What are the selection criteria for drying equipment?

Drying equipment is widely used in chemical, pharmaceutical, agricultural and forestry products, food, light industry and other fields. It is a general-purpose mechanical product with a large quantity. The drying equipment industry has gone through many years of history from formation and development to maturity. At present, the conventional drying equipment required by the domestic market, as well as the main drying equipment required by the international market, can basically be manufactured by China. This shows that the history of importing drying equipment in China has ended.

At present, the domestic market share of drying equipment in China has reached more than 80%. It is expected that during the “10th Five-Year Plan” period, the domestic dry equipment will occupy more than 90% in the domestic market. The focus of competition is mainly on product quality, technical level, after-sales service and price.

In the type of drying equipment, hot air heating atmospheric pressure drying equipment and vacuum drying equipment will be mainly used, and other users in special fields such as far infrared drying equipment and microwave drying equipment will gradually expand the application quantity; in food and medicine drying, The demand for larger gauge equipment in vacuum freeze-drying equipment will increase; the demand for equipment with functional combinations (such as granulation-drying, drying-filtration) will also increase; high-automatic drying equipment will be welcomed in some applications. . In addition, the appearance quality of drying equipment will receive more and more attention, and the corrosion resistance and reliable service life of corrosive material drying equipment will be of particular concern to users.

The following are the general principles for the selection of drying equipment. It is difficult to say which one or which items are the most important. The ideal selection must be based on its own conditions, and sometimes compromises are necessary.

1. Applicability: Drying equipment must first be applicable to specific materials and meet the basic requirements for drying of materials, including good handling of materials (feed, transport, fluidization, dispersion, heat transfer, discharge, etc.). And can meet the basic requirements of processing volume, dehydration amount, product quality and so on.

2. High drying rate: only in terms of drying rate, the material is highly dispersed in hot air during convection drying, the critical moisture content is low, the drying speed is fast, and the same convection drying, the drying method has different critical moisture content, so the drying rate It is also different.

3. Low energy consumption: Different drying methods have different energy consumption indexes. Generally, the thermal efficiency of conductive drying can reach 100% theoretically, and convection drying can only be about 70%.

4. Saving investment: The drying equipment that performs the same function sometimes has a very different cost, and should be chosen as the lower one.

5. Low operating costs: equipment depreciation, energy consumption, labor costs, maintenance costs, spare parts costs, etc. should be as low as possible.

6. Preference is given to drying equipment with simple structure, sufficient supply of spare parts, high reliability and long service life.

7. Meet environmental protection requirements, good working conditions and high safety.

8. It is best to make the drying experiment of the material before the selection, and to understand the drying equipment (extensions and disadvantages) that have been used in similar materials, which is often helpful for proper selection.

9. Not relying entirely on past experience, focusing on absorbing new technologies and listening to expert opinions.

Each type of drying equipment has its own specific application range, and each material can find several drying equipment that can meet the basic requirements, but only one of them is most suitable. If the selection is not appropriate, in addition to the unnecessary one-time high procurement cost, the user has to pay a heavy price throughout the lifetime, such as low efficiency, high energy consumption, high operating cost, poor product quality, and even equipment fundamentals. Can’t run normally and so on.

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What are the industrial drying equipment commonly used in industrial production?

In industrial production, due to the shape of the material to be dried (block, granular, solution, slurry and paste), and properties (heat resistance, water content, dispersibility, viscosity, acid and alkali resistance, explosion-proof and The production scale or production capacity varies greatly depending on the humidity, etc. The requirements for dry products (such as water content, shape, strength and particle size) are also different. Therefore, the types of industrial drying equipment used are also various. .

Box drying equipment, also known as disc drying equipment, is one of the oldest drying equipment for intermittent operation at atmospheric pressure. Generally small is called an oven, and large is called an oven. According to the way of gas flow, it can be divided into parallel flow, through flow and vacuum.

The parallel flow drying device is placed in the shallow tray on the tray 7, and the accumulated thickness of the material is about 10 to 100 mm. The fresh air sucked by the fan 3 is preheated by the heater 5 and uniformly sweeps across the surface of the material in each shallow tray along the baffle 6 to dry the material. Part of the exhaust gas is discharged through the discharge pipe 2, and the remaining cycle is used to increase the heat efficiency. The amount of exhaust gas circulation is regulated by a baffle of the suction port or the discharge port. The flow rate of the air depends on the particle size of the material, and the material should not be taken out of the drying equipment by the airflow. The principle is generally 1 to 10 m/s. The platter of the drying device can also be placed on the movable trolley frame to facilitate loading and unloading of materials and reduce labor intensity.

If there are special requirements for the drying process, such as drying heat sensitive materials, flammable and explosive materials or the moisture content of the materials need to be recycled, the box drying equipment can be operated under vacuum, which is called box vacuum drying equipment. The drying compartment is sealed, the shallow tray is made hollow, and the heated steam passes through. When drying, the material is heated in a conductive manner to vaporize the moisture or solvent of the material in the tray, and the vaporized vapor or solvent vapor is extracted by a vacuum pump. To maintain the vacuum inside the car.

The material flowing through the flow drying device is laid on a porous shallow plate (or mesh), and the air flow passes vertically through the material layer, and a slanted baffle is arranged between the two materials to prevent the humid air blown from the layer of material. Blow into another layer. The velocity of air through the orifice is about 0.3 to 1.2 m/s. The through-flow drying equipment is suitable for ventilated granular materials, and the drying rate is usually 8 to 10 times that of cocurrent.

The box drying device can also use flue gas as a drying medium. The advantage of the box drying equipment is that the structure is simple, the equipment investment is small, and the adaptability is strong. The disadvantage is that the labor intensity is large, the heat loss of the loading and unloading materials is large, and the product quality is not easy to be uniform. Box drying equipment is generally used for drying small quantities and varieties of materials, especially for laboratory applications.

Belt drying equipment, the drying chamber has a rectangular cross section, and a mesh conveyor belt is installed inside. The material is placed on the conveyor belt, and the air flow and the material flow in a wrong flow. During the forward movement, the material is continuously contacted with hot air to be dried. The conveyor belt may be a single layer or a plurality of layers, having a bandwidth of about 1 to 3 m, a belt length of about 4 to 50 m, and a drying time of about 5 to 120 minutes. It is usually divided into a number of sections in the direction of movement of the material, and each section can be equipped with a fan and a heater. In different sections, the direction, temperature, humidity and speed of the airflow can be different. For example, in the wet section, the operating air velocity can be larger.

Depending on the nature of the material being dried, the conveyor belt can be made of canvas, rubber, rubberized cloth or wire mesh. The material can be kept in the original state in the belt drying equipment, or a plurality of solid materials can be continuously dried at the same time, but the pile thickness and the loading density of the materials are required to be uniform, otherwise the unevenness of the ventilation may result in a decrease in product quality. The drying equipment has low production capacity and thermal efficiency, and the thermal efficiency is about 40% or less. Belt drying equipment is suitable for drying granular, bulk and fibrous materials.

 

In addition, according to the structure of the vibrating screen, the commonly used dryers are: spray vibrating screen, fluidized bed vibrating screen, air flow vibrating screen, rotary cylindrical vibrating screen, drum vibrating screen, infrared vibrating screen, high-frequency vibrating screen, etc. These vibrating screens have been widely used in the feed drying industry, which greatly supports the development of the feed industry.

 

New microwave drying equipment features

1. Selective heating. Since water molecules are best for microwave absorption, the portion with a high water content absorbs more microwave power than the portion with lower water content. This is the characteristic of selective heating, which allows uniform heating and uniform drying.

2. Energy efficient. The microwave acts directly on the material, so there is no additional heat loss, the air in the furnace and the corresponding container will not heat, so the thermal efficiency is extremely high, the production environment is also obviously improved, and the electricity can be saved by 30% compared with the far infrared heating. .

3. Short time and high efficiency. Microwave heating is a process in which the object to be heated itself becomes a heating element and does not require heat conduction. The microwave penetrates the inside and outside of the object from all sides and simultaneously achieves uniform heating in a short time, which greatly shortens the drying time.

4. Microwave drying equipment is easy to control, advanced technology. Compared with the conventional method, the device is ready to use; without thermal inertia, the operation is flexible and convenient; the microwave power is adjustable, and the transmission speed is adjustable. In microwave heating, drying, no waste water, no waste gas, is a safe and harmless high-tech.

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Different types of sludge have different requirements for drying equipment

After being dried by sludge dryer, the sludge can be used in coal-fired power plants, cement plants, garbage treatment plants and other factories to replace traditional fuels. It is important that sludge can reduce waste emissions and protect the environment. Etc. The benefits of sludge drying are no longer illustrated. As we all know, different types of sludge dryers (sludge dryer specific type information: sludge dryer classification Daquan) can dry different types of sludge, of course, the dryer requirements for sludge are not the same, specifically What are the requirements?

Drying equipment requirements for different types of sludge

1. Domestic sludge

In urban construction, the organic matter content of domestic sludge is high, generally up to 30-60%, and the water content is high, usually up to 95%-99%. Even after dehydration, there is still 60%-80% of water. At the same time, the domestic sludge contains a large number of pathogenic bacteria and parasites, which are prone to rot and stink, spread bacteria and affect people’s health. The sludge dryer can meet the characteristics of this sludge and can receive good social benefits through sterilization, drying and other processes.

Sludge dryer requirements for domestic sludge: The industrial production enterprise is required to install a complete sludge dryer. After the plate is pressed, the sludge with a moisture content of 80% is put into the material truck, and one material truck. Generally, it can carry sludge of between 300 and 500, and the sludge of the whole vehicle is sent to the drying room, and then the door is closed for drying. Start the setting parameters, run in three stages in time, and finish drying in twenty-four hours.

2. Printing and dyeing sludge

The printing and dyeing sludge accounts for 0.3-1% of the total sludge volume. It is similar to domestic sludge, has high water content, is not easy to dehydrate, and has large volume and quality. Since printing and dyeing sludge generally has a high inert substance, and the content of organic matter, pathogenic bacteria and the like is small, the calorific value is also low, and the content of heavy metals is generally high.

The requirements of the dryer for printing and dyeing sludge: The printing and dyeing sludge with a water content of about 80% is pretreated in the yard. This process not only allows a part of the water in the sludge to evaporate naturally, but also homogenizes the sludge. The pretreatment time can be determined according to the size of the stacking site and the weather conditions; in order to make the sludge fully contact with heat when it is dry, improve the efficiency of sludge drying, and at the same time create conditions for sludge granulation, it will pass The pre-treated printing and dyeing sludge is uniformly distributed into a drying device through a special feeding device to perform a drying process.

The sludge coming out from a drying device is sent to the second drying device through the screw conveyor for the second stage of drying; after the two-stage drying process, the sludge is continuously continuous with the rotation of the special drying device. Under the rolling, it is effectively dried, further granulated and ground, and gradually hardened. The sludge particles from the second drying device pass through the split sieve to use the sludge agglomerates with a particle size of 2-6 mm for firing lightweight energy-saving bricks and producing cement compacts, and the particle size is greater than or less than 2 The 6mm sludge agglomerate is used as an auxiliary fuel for coal combustion or as a landfill for landfill.

3. Paper sludge

The ash content of paper sludge is relatively large, generally can reach 50-70%, the hot land and water content are higher, generally reach 95-99%, the water content after dewatering can be as high as 70-80%, and the sludge volume is relatively large. And contains a lot of fiber. After the sludge dryer is dried, it can realize the comprehensive utilization of resources.

The requirements of the dryer for paper sludge: The paper sludge needs to be treated by the sludge concentration tank. Sludge concentration is a process of increasing sludge concentration by gravity sedimentation. After the sludge concentration is increased, the utilization rate of flocculant will be correspondingly increased, but the sludge concentration should be prevented from being too high, resulting in blockage of the pipeline for sludge transportation. Before entering the mechanical dewatering, the sludge needs to be added with flocculant for chemical conditioning, so that the sludge forms better flocs.

4. Electroplating sludge

The treatment of wastewater by electroplating is the main reason for the production of sludge. The content of organic matter in the electroplating sludge is small and the calorific value is small, and it contains many heavy metals.

Drying machine requirements for electroplating sludge: sludge containing 80%-90% moisture content is dried, the moisture content of the sludge after drying is 20%-30%, and the calorific value per ton of dry sludge after treatment It can reach 1200-2000 cards (equivalent to coal 220KG-480KG), can be mixed with coal and enter the boiler for common combustion, completely solve the troubles of sludge collection and landfill.

5. Tannery sludge

The production of tannery sludge is large, and in general, 40-80 tons of sludge can be produced every day. The organic matter content in the tannery sludge is high because a large amount of fur is generated during the leather treatment process, the content of the organic matter is very high, and there are many toxic substances.

Dryer requirements for tannery sludge: Typically, sludge contains 80% to 90% water. Working at temperatures above 650 ° C, the sludge dryer can reduce the moisture content to 10%-20%. In addition, the equipment can be applied to sludge drying in paper mills, chemical, electroplating, tanning, printing and dyeing industries, and has a wide range of applications.

6. Petrochemical sludge

In industrial production, petrochemical sludge is complex in composition and contains different types of heavy metals. Generally, petrochemical sludge contains oil, has high viscosity, high water content, small organic matter content and low calorific value.

Drying equipment requirements for petrochemical sludge: Most of the oil-containing sludge in the grease trap bottom sludge, scum, etc., enters the coking unit to replace the cold coke water of the coking tower, and at the same time recovers the oil. The remaining activated sludge and part of the oily sludge produced by the biochemical process are mixed and dried by a thin layer drying method. After drying, the materials are sent to the boiler for incineration, thereby realizing all the harmless treatment of the sludge.

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Operating instructions for paddle dryer

The dryer is a device for treating the moisture of the material. The paddle dryer is popular in many industries for its high heat utilization and heat transfer and super self-cleaning ability. Today, the drying equipment manufacturer will bring you the paddle type. The relevant instructions of the dryer’s instruction manual are introduced.

First, the operating instructions of the paddle dryer

1, installation and commissioning

1.1 Before installation, check that the components are intact and clean the inside.

1.2 After installation, check whether the grease has been injected into the bearing housing before commissioning. Otherwise, it should be filled with appropriate amount of grease. Generally, use molybdenum disulfide compound calcium base grease or other high temperature resistant grease.

1.3 Before installing the rotary joint, carefully read the rotary joint “Instruction Manual” and install it correctly to prevent damage to the gasket.

1.4 Heating or cooling medium inlet pipe should be equipped with pressure gauge and voltage regulator. A valve must be installed in front of the inlet to prevent overpressure of the equipment. The temperature of the heating medium must not exceed the rated service temperature.

1.5 For the rotary joint of the shaft part, it should be noted that the surface within 200 mm of the joint part extending into the inner cavity should be smooth and non-porous, free from rust and slag, and can reach the heating (or cooling) medium. Sealing requirements and dimensions are suitable. The same type of rotating joints are installed, and the whole machine must be commissioned after the test pressure is not leaked.

1.6 Check and debug the gear drive or chain drive to meet the mechanical transmission requirements. Check the motor and electrical equipment. Touch the motor power switch, the motor and transmission parts should be free of jamming, and make sure that the spindle is turning correctly (the blade should be pointed forwards when the blade rotates).

1.7 Start the motor to make the equipment run at no load, the operation should be smooth, and no abnormal noise should appear. For the speed control device, the speed should be adjusted within the adjustable range. When accelerating, it should be carried out slowly to check whether the speed regulation meets the requirements. No more than 30 minutes of no-load operation.

1.8 Gradually heat or cool, observe the operation, and make the heat source or cold source reach the use parameters. Equipment with cooling protection must open the cooling water valve before steaming. Gradually add materials, observe and check the dry condition of the materials, and continuously adjust the feeding amount, heat (cold) source quantity, discharge amount and rotation speed according to the needs, and then put into normal operation after reaching the design requirements.

2, paddle dryer instructions

Discharge the condensate in the steam line, then close the stop valve of the paddle dryer, open the air switch of the electric control cabinet (the corresponding display is red), and start the circulation fan of each heating chamber.

When the temperature in the drying chamber reaches 145 °C, set the switch of the speed regulating motor controller to the “on” position, then turn the speed control knob clockwise to make the pointer to the desired position. At the same time adjust the tightness of the conveyor chain, and then start feeding the dryer, pay attention to the uniformity of the feed.

The steam supply shut-off valve is opened to heat the drying chamber. When the steam working pressure is 0.4~1.0Mpa, the excellent performance of the machine can be fully utilized. By adjusting the angles of the inlet and exhaust dampers, the humidity in the drying chamber is controlled so that the material is in a dry state.

2.1 Motor use and maintenance Refer to the respective service and maintenance instructions.

2.2 Turn on the power supply, paddle dryer, and listen to the abnormal sound; in the on-site debugging process, the steam pipeline must be kept open.

2.3 Since some parts of the parts are inevitably displaced during transportation, adjustments must be made before use to ensure the normal use of the dryer.

2.4 After turning on the power, the principle of the paddle dryer, see if the temperature control table shows room temperature (No, please check the connection)

2.5 Before turning on the drive motor, first turn the inverter to the 0 position (after adding the corresponding oil), then open the drive motor (pay attention to the direction), turn the inverter to make the machine run, and see if there is any abnormality. After turning the circle, increase the speed, the paddle dryer instruction, and make sure the operation is normal.

2.6 The heating medium and steam pressure during normal use of the equipment shall not exceed 0.5 MPa.

Second, the common faults and solutions in the use of paddle dryer

1, low output

The reason is: low steam pressure or water, stirring and mixing fruit difference, material running speed is low, the material level in the machine is not suitable, there is water in the blade or hollow shaft, the water content of the feeding material is too high, the heating surface is sticky Wall or scale, moisture is not discharged smoothly, condensed water is returned to the dryer, and the blade or jacket leaks.

Suggested treatment methods: whole steam pressure, discharge condensate, increase spindle rotation, increase spindle rotation or increase equipment inclination, adjust feeding amount or discharge height, repair or replace steam trap or increase steam pressure, adjust feeding Moisture rate or return material, adjust steam temperature or feedstock humidity, clean up fouling, check exhaust pipe and exhaust fan status, increase exhaust air volume, increase exhaust air temperature or increase air intake, repair, repair or Seal the crack.

2, the discharge moisture content is high

The reason is: the material residence time is short, the feed amount is too large or too wet.

Suggested treatment methods: reduce the number of spindle revolutions or reduce the equipment inclination, adjust the feed amount or feedstock humidity.

3, the rotary joint leaks

Cause: The gasket or dynamic seal is damaged.

Recommended treatment: Check and replace the gasket or dynamic seal.

4, the condensate is not clean

The reason is that the steam does not match the hydrophobic pressure, the trap is not properly selected, and the trap is damaged.

Suggested treatment: Adjust the steam pressure or trap pressure, re-select the trap, and replace the trap.

5, the rotary joint leaks

Cause: The gasket or dynamic seal is damaged.

Recommended treatment: Check and replace the gasket or dynamic seal.

6, other solutions

If the board system is a problem, it is a useful treatment to replace the damaged parts with the accessories of the new sludge dewatering equipment. However, this method does not apply to the following conditions: the parts are low; the new parts are damaged when removed; the original parts are damaged from the head, and the parts are replaced at regular intervals.

Always contact the manufacturer. If there is any problem with the sludge dewatering equipment, consult the after-sales personnel, analyze the possible causes, and consult the repair plan. The rolling accessories are refueled and maintained every month to ensure the normal operation of the sludge dewatering equipment. If the sludge dewatering equipment shows that the main electrical equipment is idling, it is necessary to close the power supply and open the equipment cover to see if it is blocked.

The above is the introduction to the use of the paddle dryer. The normal operation of the equipment is inseparable from the standard operating procedures. After purchasing the equipment, read the instruction manual in detail and pay attention to the precautions.

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Sludge drying equipment classification

The sludge dryer can dry sludge such as domestic sludge, printing and dyeing sludge, paper sludge, electroplating sludge, tannery sludge, petrochemical sludge, etc. Moreover, it can not only dry various types of sludge. It can also dry a variety of high viscosity materials. According to the different ways of contact between the heat medium and the sludge, what is its classification?

According to the contact mode of the heat medium and the sludge: the sludge drying equipment is divided into direct heating, indirect heating and direct and indirect combined heating according to the contact mode of the heat medium and the sludge. Since the direct and indirect combined heating methods are less used in engineering, there are generally two heating methods.

First, direct heating and drying equipment:

Direct drying is the process of heating the sludge by direct contact with the sludge and evaporating the water in the sludge to obtain a dry sludge product. This technology is also called heat convection drying. The direct drying sludge dryer is a direct contact between the heat medium and the sludge, and has a high heat transfer rate, thermal efficiency and evaporation rate. There are drum drying equipment, belt drying equipment, and spray drying equipment.

The representative model is a rotary cylinder dryer with an internal crushing device; a fluidized bed with internals.
Rotary cylinder dryer with internal crushing device

The dryer adopts direct drying technology to directly mix and mix the flue gas with the sludge, so that the water in the sludge can be evaporated and a dry sludge product can be obtained.

The main part of the machine is:

A rotating cylinder that is slightly inclined with respect to the horizontal line, and the drying method adopts a downstream drying method. The material is fed from the upper end of the rotary drum through the feeding device, and the flow rate entering the same end is 1.2-1.3 m/s and the temperature is 700 °C under the flipping of the plate in the drum (5-8 r/min). The hot air flow is contacted and mixed, and the rotating crushing agitating wing is arranged in the middle of the drum, so that the material entering the dryer can be quickly broken, especially the bulk material with certain viscosity can be broken into small pieces so as to be in full contact with the hot air. The drying efficiency is improved, and the small pieces of material are further broken into granules, and after being treated for 20 to 60 minutes, the dried sludge is transported through the discharge port. A dry sludge product having a moisture content of less than 14% is obtained.

Features

Through the composite effect of the crushing agitation device and the cylinder rotation, the total heat transfer coefficient is increased to 2 to 3 times that of the ordinary rotary dryer, and can reach 300 to 500 Kcal/m3•n•°C. The crushing and agitating device crushes the material, and the contact area between the material and the hot air is increased, and the short circuit of the hot air is also prevented, so that the heat of the hot air is fully utilized. As the sludge of the municipal sewage treatment plant is added with flocculant during the dehydration process, the viscosity of the sludge is increased, and it is easy to agglomerate during the drying process, which not only affects the drying effect, but also increases the difficulty of utilization (required) The last set of mud crushing equipment). In the drying equipment, the stirring and crushing device and the kiln movable plate in the cylinder act to make the mud block broken before being hardened, and the discharging material is a powdery granular product, so that the subsequent processing or utilization process of the sludge is more convenient.

Equipment shortcoming

When the sludge enters the dryer, the moisture content is very large, generally about 80%. At this time, the evaporation amount is large and the drying efficiency is higher. However, since it cannot be broken at this time, the sludge has a low degree of contact with hot air and the evaporation efficiency is low. When the crusher is in effect, the moisture content of the material is generally below 40%. At this time, the material has been run to more than half of the rotary cylinder, resulting in insufficient effective space. For occasions with high moisture requirements (such as 50%), the drying efficiency is lower, and it is generally too dry and waste. The exhaust gas exchanged with the sludge is generally discharged into the atmosphere at about 100 degrees, which wastes a large amount of heat source, increases the operating cost, and also causes atmospheric pollution.

Adaptation scale: Rotary cylinder dryer with in-band crushing device, equipment with moderate investment, high civil construction investment, high energy consumption, suitable for single machine processing capacity below 5 tons / hour, final moisture requirement is lower (less than 20 %) in the sludge drying project.

Fluidized bed with internals

The machine adopts a composite heating method of direct heating by hot air and conduction heating of internal parts to continuously dry the sludge, and a heat exchange tube bundle with different layouts is arranged in the fixed fluidized bed, and boiler steam is introduced into the bundle, and the boiler steam is a heating medium. . The air is heated by a steam heater disposed outside the fluidized bed, and then enters the fluidized bed, and the added sludge is blown in the bed to exchange heat, collide, and pulverize with the internal parts. The materials that meet the moisture and particle size requirements are taken out of the dryer by hot air and collected by a cyclone and a bag filter. The unsatisfactory materials are circulated and dried in the dryer.

Features

The internal parts play the role of crushing and conduction heat transfer, so that the fluidized bed which can not dry the sludge can be used to dry the sludge, which has the characteristics of large fluidized bed treatment, and the conductive heating internal parts play a certain energy saving. effect. The drying strength is improved.

Equipment shortcoming

The sludge particles collide with the inner parts for a long time, which shortens the life of the inner parts. There is hot air intervention, taking away heat, increasing energy consumption and increasing operating costs.

Adapt to scale

One-time equipment is moderate investment, civil construction investment costs are high, and energy consumption is too large. It is suitable for single sludge treatment with a capacity of 8 tons/hour and a low moisture content.

Second, indirect heating and drying equipment:

Indirect thermal drying, also known as heat conduction drying, in the process of operation, the heat medium does not directly contact the sludge, but the heat is transferred to the wet sludge through the medium, so that the water in the sludge can be evaporated. There are rotary drying equipment, membrane drying equipment, paddle drying equipment, and multi-layer step drying equipment.

Representative models are: hollow paddle blade dryer, disc dryer.

Hollow paddle dryer

The hollow blade dryer is a horizontal agitating dryer mainly based on heat conduction. Because the inner hollow agitating blade is shaped like a paddle, it is called a hollow blade dryer.

Features of the equipment: adjustable material retention time, can handle high water content materials, can also obtain very low water content materials; typical conduction drying method, energy saving, large transmission coefficient, high thermal efficiency; all the heat required is supplied by hollow blades and jackets, In order to reduce the humidity of the exhaust gas, a small amount of hot air can be added, the dust entrainment is low, the exhaust gas is easy to handle, and auxiliary equipment such as dust removal is not required. The blades have self-cleaning ability. The blades rotate in opposite directions, and the two inclined surfaces of the blade repeatedly stir, compress, relax and propel the material, so that the page has a unique self-cleaning ability, the heating surface is continuously updated, and the heat transfer coefficient of the blade dryer is higher than any other conduction. Drying method.

Disc dryer

The disc dryer is an indirect heated contact dryer designed for viscous products. The heating zone consists of a double-walled disc that is mounted on the hollow shaft at specific intervals; the transport paddle is mounted around the disk, along the axial direction. Transfer material.

Third, direct, indirect combined drying equipment:

The direct, indirect combined drying system is the integration of convection-conduction technology. Common equipment fluidized bed, etc.

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Drying equipment characteristics, classification, principle and material requirements

Drying equipment is a kind of mechanical equipment that uses heat to reduce the moisture of materials and is used to dry objects. The drying apparatus vaporizes moisture in the material (generally referred to as moisture or other volatile liquid component) by heating to obtain a solid material having a specified moisture content.

The purpose of drying is for the purpose of material use or further processing. For example, the drying of the wood before the production of the wood mold and the wood can prevent the deformation of the product, and the drying of the ceramic material before the calcination can prevent the product from cracking. In addition, the dried material is also convenient for transportation and storage, such as drying the harvested food to a certain moisture content to prevent mildew. Since natural drying is far from meeting the needs of production development, various mechanized drying equipments are becoming more and more widely used.

Drying equipment features

Characteristics of drying equipment Most dryers are non-standard equipment, mainly because the materials processed by each dryer are different. Many drying conditions change with materials, which leads to changes in the structure and materials of the dryer. .

Therefore, it is necessary to clarify the specific parameters of the material to be dried, such as the state of the material, the type of moisture contained, the amount of treatment, the characteristics of the material during the drying process, whether it is corrosive, burning and explosive, whether static electricity is generated, the specific requirements of the product, and the heat sensitivity of the material. The temperature, etc., can determine the various parameters of the dryer. For this reason, many dryers cannot be mass-produced, and attention must be paid to the material’s pertinence and adaptability to working conditions during the design process.

Classification of drying equipment

Types of drying equipment So far, there have been hundreds of drying equipments that have been successfully developed, and there are more than one hundred kinds of drying equipment commonly used in industrial production. There are various classification methods for drying equipment. If the heat transfer method according to the drying process can be divided into convection dryers (such as air flow dryers, spray drying equipment, rotary quick dryers, fluidized bed dryers, etc.), conduction heat transfer. Dryers (such as sputum dryers, roller dryers), radiation dryers (such as microwave dryers, far infrared dryers), etc. In addition, there are drying equipment such as paddle dryers that combine several heat transfer methods.

There are many types of drying equipment. According to the operating pressure, it can be divided into normal pressure and decompression (decompression drying equipment is also called drying equipment). According to the operation method, it can be divided into batch type and continuous type. According to the drying medium, it can be divided into air, flue gas or other drying medium. According to the movement (material movement and drying medium flow), it can be divided into cocurrent, countercurrent and crossflow.

Press operating pressure

According to the operating pressure, the drying equipment is divided into two types: atmospheric drying equipment and vacuum drying equipment. Under vacuum operation, the wet partial steam partial pressure can be reduced to accelerate the drying process, and the wet boiling point and material drying temperature can be lowered. Leakage, therefore, the vacuum dryer is suitable for drying heat sensitive, oxidizable, explosive and toxic materials and wet steam needs to be recycled.

By heating

According to the heating method, the drying equipment is divided into a convection type, a conduction type, a radiation type, a dielectric type and the like. Convection drying equipment, also known as direct drying equipment, uses a hot drying medium to directly contact wet materials to transfer heat in a convective manner and to carry the generated steam away; a conductive dryer, also known as an indirect dryer, utilizes conduction. The heat is transferred from the heat source to the wet material through the metal partition wall, and the generated wet steam can be removed by vacuum suction, a small amount of purge gas or condensation on the surface of the separately disposed low temperature condenser. This type of drying equipment does not use drying medium, has high thermal efficiency, and the product is not polluted, but the drying capacity is limited by the heat transfer area of ​​the metal wall, the structure is also complicated, and it is often operated under vacuum; the radiant drying equipment utilizes various radiations. The electromagnetic wave emitted by a certain wavelength range is selectively absorbed by the surface of the wet material and then converted into heat for drying; the dielectric drying device utilizes a high-frequency electric field to cause a thermal effect inside the wet material to be dried.

According to the way the wet material moves

According to the movement mode of wet materials, the drying equipment can be divided into fixed bed type, agitated type, spray type and combined type; according to the structure, the drying equipment can be divided into box drying equipment, conveyor type drying equipment, drum type drying equipment, and Drying equipment, mechanical agitating drying equipment, rotary drying equipment, fluidized bed drying equipment, airflow drying equipment, vibrating drying equipment, spray drying equipment, and combined drying equipment.

The drying process of the drying equipment requires a large amount of heat energy. In order to save energy, some materials with high moisture content, suspensions or solutions containing solid substances are generally mechanically dehydrated or heated and evaporated, and then dried in a dryer to obtain a dry solid.

In the drying process, the drying equipment needs to complete the transfer of heat and mass (moisture) at the same time, ensuring that the moisture partial pressure (concentration) of the surface of the material is higher than the partial pressure of moisture in the external space, and the temperature of the heat source is higher than the temperature of the material.

Heat is transferred from the high temperature heat source to the wet material in various ways, so that the surface of the material is vaporized and escaped to the external space, so that the difference in moisture content occurs on the surface and inside of the material. The internal moisture partition diffuses and vaporizes to the surface, so that the moisture content of the material is continuously reduced, and the overall drying of the material is gradually completed.

The rate of drying of the material depends on the rate of surface vaporization and the rate of diffusion of the internal moisture. Usually, the drying rate in the early stage of drying is controlled by the surface vaporization rate; then, as long as the external conditions of drying are constant, the drying rate and surface temperature of the material remain stable. This stage is called the constant-speed drying stage; when the moisture content of the material is reduced to a certain To the extent that the rate of diffusion of the internal moisture to the surface decreases and is less than the surface vaporization rate, the drying rate is mainly determined by the internal diffusion rate and decreases with the decrease of the moisture content. This stage is called the slow-down drying stage.

Drying equipment requirements for materials

The materials processed by the drying equipment are difficult to count. In addition to the physical and chemical properties of various materials and the requirements of the products, the thermophysical properties of the materials in the drying process and the material requirements for the drying system equipment during the heating process are more important issues for designers. Some methods are proposed for the use of drying equipment for designers’ reference.

Preface Drying equipment is one of the most widely used unit equipment. It can be considered that the application of drying equipment has spread throughout the various departments of national production. For drying equipment, it must not be simply considered to be a thermophysical dewatering machine. Due to the different materials processed during the drying process and the different types of wet materials, the various indicators of the products are also different. The installation location of the equipment is different. There are different requirements for the selection of the drying equipment, the type of equipment, and the manufacturing and installation methods. Proper handling of these issues is one of the important factors in the successful design of drying equipment.

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What are the benefits of using a sludge dryer?

With the improvement of people’s environmental awareness, the sewage treatment industry has developed rapidly and the production of sludge has increased significantly. All know the harmful substances in sewage sludge, such as pathogenic microorganisms, parasitic eggs and many other risk factors. At this time, a sludge dryer is needed. Why use a sludge dryer? What is the significance and value of the sludge dryer?

First, introduction to sludge dryer

The sludge dryer quickly passes through the “adhesive phase region” during the drying process. At the same time, the ingenious structure makes the sludge reach the bidirectional shear state during the drying process. The dried sludge is continuously and continuously fed into the feeding port of the dryer by the screw feeder. After the sludge enters the body, the sludge is turned over and stirred by the rotation of the blade, and the heating interface is continuously updated to contact the body and the blade. It is heated sufficiently to evaporate the surface moisture contained in the sludge.

At the same time, the sludge is conveyed in the direction of the discharge port with the rotation of the blade shaft in a spiral path, and the stirring is continued during the transportation, so that the water oozing out from the sludge continues to evaporate. The uniformly dried product is then discharged from the discharge port. The jacketed shell structure is adopted, so that the sludge is uniformly heated at various interfaces inside the machine, the shaft body rotates, the sludge does not churn in the equipment, and the heated surface is continuously refurbished. Thereby, the steaming rate of the equipment is greatly improved, the purpose of sludge drying is achieved, and the low-cost operation of the whole device is realized.

Different materials are selected for different drying processes. It is very important to choose the correct drying process. The single-drum dryer does not dry for the material to make the color of the baked material poor. The sludge is a kind of material that is not easy to dry, so that the dried material is dry and uneven. The DC vortex and AC reciprocating quick dryer make the baked materials have good color and save resources and improve economic benefits.

Second, the significance of sludge dryer

Sludge is a solid precipitation material produced by water and sewage treatment processes. Its main characteristics are: high water content (up to 99% or more), high organic content, easy to rot and odor, and fine particles, small specific gravity, and a gelatinous liquid state. The main sources of sludge are: domestic sewage sludge, industrial wastewater sludge and water supply sludge. The disposal and treatment of various sludges has become a stubborn disease that restricts urban development and urban sanitation.

With the strengthening of energy conservation and emission reduction, the improvement of people’s environmental awareness and the increasing production of municipal sludge, the problem of sludge disposal and development and utilization has become an important issue in environmental protection. The development of sludge drying treatment technology has made sludge agricultural, sludge fuel and sludge incineration possible. The improvement and innovation of sludge drying technology and sludge dryer directly promoted the development of sludge disposal methods, expanded the selection of sludge disposal methods, and made them in terms of safety, reliability and sustainability. More and more reliable guarantees.

In the environmental protection industry, sludge treatment and disposal is still a relatively backward domain. It is also a domain that I urgently need to accelerate. Along with the expansion of the scale of urban sewage treatment, sludge is also produced as a by-product of sewage treatment. According to the average solid content of 0.02% of municipal sewage on a dry matter basis, it can produce 31,400 tons/day of dry sludge. According to the 80% moisture content before sludge dewatering, 157,000 tons of wet sludge is produced every day. In the year of 360 days, the annual production of wet sludge is about 56.52 million tons.

The sludge has complex composition and contains pathogenic microorganisms, parasitic eggs, toxic and harmful heavy metals and a large number of refractory substances. If improperly treated, it is easy to cause secondary pollution to the environment. However, my sludge disposal rate is very low, and the sludge has not been disposed of in a harmless manner, posing a serious threat to the ecological environment.

Third, the value of sludge drying after using sludge dryer:

1. Incineration treatment:

The dried sludge has a calorific value of about 1300 to 1500 kcal. The three tons of dried sludge can be equivalent to 4,500 kcal of coal, which can be mixed in coal to burn in the boiler. The sludge can produce tons of steam. The blending ratio of dry sludge to coal is 100 to 200 kg of sludge per ton of coal.

2. Sludge brick:

It can be added into clay to make bricks with a mass ratio of 1:10. Its strength is equivalent to that of ordinary red bricks, and it has a certain calorific value. During the process of firing bricks, it can spontaneously ignite and increase heat.

3. Biochemical fiberboard:

Under alkaline conditions, a series of physicochemical changes (globulin denaturation) occur after heating, drying and pressurization. The activated sludge resin (protein glue) is made by this denaturation, and the fibers are bonded and pressed. Plate.

4. Admixtures in cement plants.

5. Landfill compost:

Because the sanitary landfill management is not in place, it is easy to produce secondary pollution. In addition, the company has formulated relevant standards and technical policies for sanitary landfill. The water content of the mixed landfill for printing and dyeing sludge is less than 60%, and the transverse shear is greater than 25KN/ Square meters. In fact, the moisture content of the de-cemented cake is more than 80%. The direct landfill treatment has been restricted by the current regulations, and direct landfill is not allowed. The family has increased law enforcement in this regard.

Composting treatment Because organic sludge contains nitrogen, phosphorus and potassium, it is a necessary fertilizer component for crop growth. The crude protein or globulin of the organic component in the activated sludge is a good soil conditioner, and the sludge has stable properties and can be used as a fertilizer, which has agricultural utilization value. But until now, the composting treatment of printing and dyeing sludge in the society is still unacceptable and has not been promoted.

After reading the article, did you find that it is very meaningful and valuable to use the sludge dryer? After the sludge is dried, the sludge becomes waste and the danger is avoided. Waste has become a treasure that can be used.

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How to deal with industrial sludge?

At this stage, the total amount of industrial sludge is on the rise. If it is discharged without treatment, it will cause great harm. So, how do you know how to treat industrial sludge? There are also many methods for sludge treatment. The following is a detailed description of the industrial sludge treatment method and provides you with an ideal solution for industrial sludge treatment.

First, how to deal with industrial sludge?

1. Drying heat treatment

The so-called drying heat treatment is to use the drying equipment to treat the sludge and make progressive use of the sludge. This method will reduce the volume of the sludge and make the sludge more stable, eliminating the odor of the sludge and Pathogenic organisms. The sludge after drying can be used as both a soil improver and an energy source. At present, the technology has gradually matured and is used by some developed homes.

2. Incineration treatment

Incineration is a traditional way of treating sludge in sewage treatment plants. By incineration, organic matter and pathogens in the sludge can be eliminated, and the volume of sludge can be reduced to a large extent. However, this treatment requires processing with expensive equipment, a large amount of treatment, and harmful gases are generated during the incineration process, and the sewage treatment plant must be progressively treated to treat these harmful gases.

3. Landfill treatment

Compared with other sludge disposal methods, landfill treatment is a relatively simple treatment method, and the cost of landfill is less. This method is a relatively mature sludge treatment method. However, landfill sludge treatment is poor and limited by land resources. At the same time, landfill sludge may affect local groundwater, etc., and pollute the groundwater. In order to avoid this problem, the sewage treatment plant must reduce, stabilize and harm the sludge. In order to ensure that it will not pollute the soil and groundwater, maintain a good ecological environment.

4. For agriculture

As far as the sludge itself is concerned, it contains some organic matter that can be converted into nutrients needed by the soil. For this reason, the sewage treatment plant can use the organic matter in the sludge for agriculture, which becomes a way of treating sludge. In this way, the fertilizer of the sludge can be used in forest land, vegetable fields and fields, and the pollution caused by the sludge is reduced, and it becomes a relatively green treatment.

Through the introduction of the above sludge treatment method, we can find that if it is for a large amount of industrial sludge, the practical method for reducing environmental pollution is to carry out dry heat treatment, which requires the use of a professional treatment equipment is a sludge dryer.

Second, the advantage of sludge dryer treatment sludge

Industrial sludge heat pump dryer can fully realize the utilization of municipal sludge reduction, stabilization, harmlessness and resource utilization. The final sludge particles can be turned into fertilizers, fuels, incineration, building materials, landfills, biofuels, etc.

The sludge dryer drying system is highly adaptable and can even be used for materials that are difficult to handle. The entire drying system is easy to control. It can be applied to a variety of fuels, such as various natural gas and petroleum. Throughout the drying process, the operator can observe the burning rate through a temperature instrument in the dryer discharge tube. The sludge dryer drying system can use a variety of fuels, such as electricity, oil, natural gas and the like. The hot air of the drying system can be secondary or secondary indirect hot air. The sludge dryer has a good dry fruit, which reduces the investment cost. No secondary pollution, good safety performance and low investment. After the drying process, the sludge can be reused as a useful secondary resource.

The sludge dryer has a wide range of drying and is available for customers to choose from. Drying capacity can range from 100kg/h to tens of tons per hour. The equipment has a reasonable structure and a small footprint. Lower energy consumption and lower operating costs. The system has a higher heat rate due to the air exchanger and the waste heat boiler. Compared with traditional drying systems, sludge dryer energy consumption can be reduced by 20%-30%. The dried fruit is remarkable.

The entire drying system is environmentally friendly. With a complete exhaust gas treatment system, rotary dust removal system and bag filter, it emits almost no dust to the air. The acid-base neutralization process and the dust precipitation process are carried out simultaneously, and the odor can be completely eliminated. Therefore, the exhaust gas can reach the emission standard.

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Slime dryer maintenance tips

We all want to buy a slime dryer that can last longer, so how can we make the slime dryer increase its lifespan and use it for a longer time? Of course, it is to maintain the maintenance of the slime dryer. If you find the problem ahead of time, solve the problem, can you improve the work efficiency, and the machine can always be in good condition, then let’s take a look at the slime dryer. Maintenance!

First, the maintenance rules for slime dryer

1. Daily maintenance and maintenance

(1) First of all, before we turn on the machine every day, we should check the triple piece to see if the oil is sufficient. If it is insufficient, we need to add the lubricating oil. The need to pay attention is to discharge the accumulated water.

(2) It is necessary to wipe the machine with a softer cotton cloth or a softer rag every day to keep the appearance clean and rust.

(3) The fluff inside the dust box can be cleaned by hand blower or vacuum cleaner every day, which can ensure the effective ventilation of the machine and make the machine perform the best drying effect.

2. Monthly maintenance and maintenance of the dryer.

(1) Lubricating oil is added to the moving parts such as bearings every month to avoid improper friction. Open the rear cover and clean the inside of the device with a soft cotton cloth.

(2) Use a soft cotton cloth or cloth strip to clean and maintain the equipment inside the back cover box every month.

(3) Especially for new machines, with running-in period and long time of vibration, it will cause loose screws or loose parts, such as the rocker arm of the door, the screws at the pipe joints, etc., and strengthen the fastening.

(4) Always check if the belt is loose or too tight. Adjust the transfer wheel as appropriate.

3. Maintenance and maintenance of the annual dryer

(1) Check the sensitivity of the circuit control, wind turbine and heat exchanger. It is necessary to solve it when it needs to be adjusted or replaced. Check that the mounting bolts on the base are loose and strong.

(2) Check if the parts of the machine are grounded to avoid causing certain damage to the parts caused by machine shaking.

(3) Check the spring tension of each part of the dryer and adjust it in time.

(4) Check if the screws on the base of the dryer are loose and tightened.

(5) Carry out statistical reports on the thermometer or thermometer on the equipment and submit it to the local technical supervision bureau for a comparison report.

Second, the slime dryer maintenance knowledge

First of all, if the slime dryer is working outdoors, it must be waterproof. The main material of the slime dryer is steel. If there is too much water, it will increase corrosion. Therefore, we must do a good job in rainproof sheds and other facilities, and do a comprehensive paint protection every two years.

Secondly, the hot air blower needs to add lubricating grease after working for about 100 hours. The motor is replaced with butter for maintenance for about one thousand hours of operation. The hoist and conveyor bearings need to be filled with grease every shift. This not only prevents wear and tear, but also reduces the temperature of the motor and prevents the motor from burning out. Every quarter, it needs to be replaced and maintained, the debris in the air duct of the dryer is cleaned, the fan is cleaned of the blade adhesion, and the speed regulating motor speed gauge is returned to zero.

Third, the use of slime dryer maintenance experience

1. During normal operation, the inlet hot flue gas temperature is 800-700 °C, and the outlet hot flue gas temperature is 90-150 °C.

2. Check whether the lubrication points of the rolling ring, the supporting wheel and the supporting wheel bearing are sufficient.

3. There is no weld crack between the rolling ring and the backing plate of the slime dryer, and there is no excessive wear between the rolling ring and the supporting wheel.

4. Whether the contact between the rolling ring and the supporting roller is good, the contact surface is not less than 70% of the width of the rolling ring.

5. Whether the thrust of each roller is consistent and even upward.

6. Whether the fastening bolts and anchor bolts are loose or broken.

7. The foundation has vibration, cracks and sinking.

8. Whether the rotation of the retaining wheel is flexible, whether it is in good contact with the rolling ring, whether there is excessive force and the surface of the retaining wheel is bright, and the lifting of the shell and the heating of the bearing are abnormal.

9. Whether the cylinder is flexible or stable, and whether the seal is worn or leaked.

10. Whether the transmission assembly is vibrating, and whether the lubrication point is sufficient.

In summary, everyone has an understanding of the maintenance of the slime dryer, correct maintenance, precautions, potential problems and solutions in advance, always in good condition, the service life will naturally last for a long time!

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Hollow paddle dryer installation method

The hollow blade dryer is a low-speed agitating dryer that allows the wet material to be in contact with the heat carrier and the hot surface under the agitation of the blade to achieve the purpose of drying, and can be classified into hot air type and conductive type. Two structures. The installation of the equipment has a very important impact on the later use and maintenance. Let’s take a look!

First, the installation environment, equipment quality, need consumables testing

1. Read the instructions for the main unit and auxiliary machine and related documents carefully before installation to develop a detailed installation plan. Before installation, check the number and integrity of all equipments one by one according to the packing list. Check for foreign matter inside and outside the equipment.

2. Inspect the strength, size, elevation, flatness, anchor bolt holes, etc. of each foundation to meet the design requirements. Clean or purge the base surface and bolts to the buried holes to remove debris, grease and ash.

3. Three-phase four-wire system 380V, 50Hz power supply, voltage fluctuations can not exceed 10%.

4. The air humidity is not more than 95%.

5. Electrical appliances and dryers must be effectively grounded.

6. It is best to use heat preservation for steam pipes and drying machines to avoid accidents such as burns.

7. The humidity of the installation environment should be suitable and not too humid to avoid the short circuit of the electrical appliance and the rust of the outer casing.

8. Not easy to install in the wood chips, dusty places such as the grinder, blocking the radiator.

9. Do not install in a place with or with items to avoid accidents.

Second, hollow blade dryer installation method

1. Hollow paddle dryer mainframe installation

The main unit is tilted at a certain angle according to the design requirements, or installed horizontally. Tighten the anchor bolts after installation.

2. Installation of auxiliary equipment for hollow blade dryer

a. Install parts and accessories that are shipped separately at the factory according to the instruction manual or other indicative documents.

b. When installing the adapter, you should carefully read the “Rotary Connector Instruction Manual” to prevent the gasket from being damaged.

3. Hollow blade dryer mud pump installation

a. Check the pump and motor to verify that there are no injuries during the transportation and loading and unloading process.

b. Prepare tools and lifting equipment, and review the basics of the machine according to the diagram.

c. The whole set of pump bottoms is equipped with motors. When leveling the base, the pump and motor can be removed.

d. Place the base in the basics, prepare to fill the concrete after leveling, level the anchor bolts after leveling, and fill the anchor bolts with concrete.

e. Place the steel ruler on the coupling. It is necessary to measure the upper, lower, front and rear, and check whether the axial line of the pump and the motor can coincide.

f. After the concrete of the anchor bolt to be fixed is completely dry, tighten the nut of the anchor bolt, and then check the degree of the whole pump set. It is slightly uneven and can be leveled by wedge iron.

g. According to the water absorption and outlet pipelines, when the pipeline is combined with the pump, it should be noted that the component and pressure of the pipeline should not be added to the pump to avoid the deformation of the pump.

Third, the hollow blade dryer installation precautions

1. The steam trap is generally purchased by the customer. It should be properly selected according to the process requirements. The displacement and drainage pressure are suitable. The drainage is thorough and has the function of discharging non-condensable gas. The trap should be installed at the lowest point of the equipment and the line should be provided with a bypass valve. If the trap is connected to the water storage tank or directly to the boiler room, a check valve should be installed behind the trap.

2. On the pipe network of steam inlet, pressure regulating valve, pressure gauge and safety valve should be installed to limit the maximum steam pressure to avoid accidental damage to the machine.

3. Ensure that the fixing bolts of the base are not loose and the springs are tightly connected. The control of the computer board, the wind wheel and the heat exchanger have good flexibility.

Fourth, hollow blade dryer dryer debugging method

1. After installation, check whether the grease has been injected into the bearing housing before commissioning. Otherwise, the appropriate amount of grease should be added. Generally, the molybdenum disulfide compound calcium base grease or other high temperature resistant grease is used.

2. Check and debug the gear drive or chain drive to meet the mechanical transmission requirements.

3. A pressure gauge and a voltage regulator should be installed on the inlet or outlet of the heating or cooling medium. A safety valve must be installed in front of the inlet to prevent overpressure of the equipment. The temperature of the heating medium must not exceed the rated service temperature.

4. Conduct safety inspections on electric motors and electrical appliances. Touch the motor power switch, the motor and transmission parts should be free of jamming, and make sure that the spindle is turning correctly (the blade should be pointed forwards when the blade rotates).

5. For the rotary joint with single-end configuration at the end of the shaft, it should be noted that the surface within 200 mm of the end of the nozzle extending into the inner cavity should be smooth and non-porous, free from rust and slag, and can be heated (or Cooling) The sealing requirements of the media are of a suitable size. As with the double-end installation of the rotary joint, the machine must be tested without leaking.

6. Start the motor to make the equipment run at no load, the operation should be stable, and no abnormal noise should appear. For speed control devices, the speed should be adjusted within the adjustable range. When accelerating, the speed should be slow to check whether the speed regulation characteristics meet the requirements. No more than 30 minutes of no-load operation.

7. Gradually heat or cool, observe the operation, and make the heat source or cold source reach the use parameters. Equipment with cooling protection must open the cooling water valve before steaming.

8. Gradually add materials, observe and check the dry condition of the materials, and continuously adjust the feeding amount, heat (cold) source quantity, discharge amount and rotation speed according to the needs, and then put into normal operation after reaching the design requirements.

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