Gravity flow type indirect cooler

Abstract

The utility model belongs to the field of material cooling, and particularly relates to a gravity flow type indirect cooler, which is characterized in that dry gas is introduced into a recooler body through a fluidization air gas distribution component, so that materials in a material fluidization section are in a fluidized state, and the materials fed from a feeding hole are quickly spread in the horizontal direction, and the material cooling efficiency is improved. Uniform particle distribution is formed in the cross section of the cooler, so that the materials integrally and uniformly move downwards to pass through a gravity cooling section, and material segregation and non-uniform cooling caused by different cooling speeds of the materials are eliminated; and the materials are fluidized by using dry gas, so that wet and hot gas brought along with the materials and moisture in pores or air holes on the surfaces of material particles can be more effectively removed, thereby avoiding scabbing of the materials on the surface of the heat exchanger assembly, ensuring more uniform cooling of the materials and more uniform moisture of the materials at all positions, and improving the heat exchange efficiency of the heat exchanger assembly. And the problems of hardening and caking in the storage and transportation process of the product can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to material cooling field, it is a gravity flow type indirect cooler. BACKGROUND

[0002] The product obtained through the microbial fermentation is one of the main production modes of the biological chemical industry. Due to the complex composition of the fermentation broth, containing various organic and inorganic metabolites, the main and by-product obtained by the post-processing of the crude fermentation broth inevitably contains various impurity components, resulting in the phenomenon of sticking and hardening of the product during storage and transportation, reducing the quality of the product and increasing the cost of transportation and fertilization.

[0003] Generally, the powder and granular products of fermentation plants need to be dried to the qualified moisture by different forms of dryers first, and then cooled to near room temperature by fluidized bed, rotary cylinder and other cooling equipment before packaging. However, for the fluidized bed, rotary cylinder and other cooling equipment, since the air directly contacts the material, the moisture will also enter the material from the air while the material is being cooled; or due to incomplete cooling process of the material, heat and moisture will migrate between the inside and surface of the material particles after cooling is completed, and between the surface of the particles and the air in the surrounding gap, etc., ultimately leading to caking, hardening and other phenomena. In order to avoid product caking, the current tendency is to reduce the moisture content of the product to far below the equilibrium moisture under ambient conditions in the drying link, and based on the characteristics of the fermentation product being easy to absorb moisture, the ambient air, especially the ambient air in the hot and humid season, is used as the coolant. While cooling the material, the moisture in the air will also enter the material, causing the material to absorb moisture; there are certain gaps between the particles of bulk material, and the humid air filling the gaps will enter the closed environment of the packaging bag, and the moisture absorption process on the surface of the particles will also cause the particles to further stick together; and if the temperature of the packaged material is higher than the ambient temperature, the moisture inside the particles will continue to migrate to the surface and continue to be released into the gap during the continuous heat dissipation process of the material to the environment, which will also continue to increase the humidity of the air, and further cause the particles to stick together. Therefore, for the equipment that directly contacts the material with air for cooling, the air needs to be deeply dehumidified to avoid the material absorbing moisture during the cooling process, and the air in the gap of the material particles is replaced with dry air; due to the efficiency problem of the cooling equipment, in order to cool the material to the ambient temperature (such as cooling the material to below 25-35℃ in summer), a lower inlet air temperature and a lower relative humidity at the inlet air temperature (such as: dry bulb temperature 20℃, relative humidity 20%) are required, but the air is humid in summer and autumn, and the energy consumption of the dehumidification and cooling link is relatively large, sometimes even accounting for more than 20~30% of the energy consumption of the drying process. And during the cooling process, the particles are in a state of intense motion, and the friction between the particles and the wall surface of the cooling equipment will cause the particles to be abraded, new dust generated by friction will enter the product, which will reduce the product quality and increase the degree of product caking.

[0004] In recent years, the fertilizer industry, especially the urea industry, has begun to introduce cooling devices for indirect heat transfer of bulk solid materials from international sources. Compared with fluidized bed coolers, these devices have significant technological advantages in energy saving, emission reduction, and cooling depth. The main body of this cooling device is a vertically arranged container, divided into three sections from top to bottom: a feeding section, a cooling section, and a discharging section. The cooling section is equipped with a heat exchanger. Free-flowing solid particles enter the container through the inlet of the feeding section and move slowly downwards under gravity. As they flow through the cooling section, they pass through the external channels of the heat exchanger, where heat is carried away by the refrigerant, cooling the material to the required temperature. The material then enters the shell of the discharging section and is discharged from its outlet. Because the material is in a slow, continuous flow state during the cooling process, friction between particles and between particles and the wall is minimal, and particle wear is essentially eliminated. Furthermore, due to the indirect heat transfer method, the material is largely in contact with air, avoiding an increase in the product's moisture content during cooling.

[0005] However, when processing granular products from fermentation plants, whether they are crystalline products or granules produced by granulation and drying of multi-component blends, some common problems exist when using gravity flow coolers for cooling:

[0006] (1) After absorbing moisture, the material is prone to forming scale on the heat exchanger wall, especially the wall of the heat exchanger located above the gravity flow cooler. This will lead to a significant decrease in heat exchange efficiency and may even cause blockage of some material flow channels in severe cases. In addition, the material itself will also form clumps after absorbing moisture.

[0007] (2) In gravity flow coolers, it is generally desirable for the material to flow downwards at a uniform speed across the entire cross-section of the cooler, i.e., to move downwards in a so-called overall flow manner, thereby achieving the best cooling effect. However, the actual application is not always so ideal, especially for materials that are prone to moisture absorption, clumping, and scaling. The clumping and scaling of the material exacerbate the unevenness of the overall flow of the material, resulting in greater differences in the degree of cooling of the material in different areas of different cross-sections of the cooling equipment. This leads to some materials still having a higher temperature, and even if the average discharge temperature meets the requirements, these materials may still caking during long-term storage.

[0008] The above problems have limited the application and promotion of gravity flow coolers in the fermentation industry or industries with similar material characteristics, making them unable to replace traditional, mature direct contact cooling devices such as fluidized beds and rotary cylinders.

[0009] Chinese patent document CN110701927A (201910776877.2) discloses a material cooling system based on a powder flow cooler. The above-mentioned material cooling system can effectively avoid scabbing of the powder flow cooler wall surface and material caking during the cooling process. However, since the above-mentioned material cooling system needs to increase the temperature of the coolant in the powder flow cooler to reduce the temperature difference between the coolant and the material in the powder flow cooler, the temperature of the coolant must be greater than the dew point value of the material. However, the material after drying is usually still at a high temperature, and the material cannot be cooled by a lower temperature coolant, resulting in a decrease in overall cooling efficiency. In addition, after the dry air introduced into the material cooling system absorbs the moisture in the material, it will collect upwards. In addition, the material sent into the material cooling system contains a large amount of hot and humid gas, so the humidity of the upper material at the top of the material cooling system is large. In order to avoid scabbing, the entering temperature of the coolant in the upper powder flow cooler needs to be further increased, resulting in a further decrease in overall cooling efficiency. Practical new type content

[0010] The main purpose of the present utility model is to provide a gravity flow type indirect cooler, the present utility model passes through setting material fluidization section and gravity cooling section from top to bottom in heavy cooler body, passes through fluidization wind gas distribution subassembly and introduces dry gas into heavy cooler body, makes material of material fluidization section present flow state, guarantees that gas passes through material uniformly upwards, thereby make material sent into from feed inlet spread fast in horizontal direction, and form even particle distribution after in cross section of cooler, pass through gravity cooling section and move down uniformly as a whole, eliminate material segregation and cooling unevenness caused by different cooling speed of material everywhere, and utilize dry gas to material flow state, can remove humid heat gas and moisture in material particle surface capillary hole or air pocket brought with material more effectively, make material after replacement of fluidization wind be in dry gas environment and enter indirect cooling process, thereby avoid material scabbing on surface of heat exchanger subassembly, guarantee material cooling more evenly, moisture of material everywhere is more uniform, help to adopt lower temperature refrigerant to material cooling, improve cooling efficiency, and help to improve product storage and transportation process problem such as hardening, caking.

[0011] The technical problem to be solved by the present utility model is solved by the following technical scheme: a gravity flow type indirect cooler, comprising a heavy cooler body, a gas distribution assembly, a heat exchanger assembly, a gas supply system and a heat exchange medium supply system.

[0012] The heat exchanger assembly is a plate heat exchanger or a tube heat exchanger, and a first material passage penetrating up and down is arranged between the heat exchange plates or the heat exchange tubes of the heat exchanger assembly.

[0013] The gas distribution assembly is horizontally arranged in the heavy cooler body, and comprises air distribution units arranged at intervals along the cross section of the heavy cooler body and second material passages arranged between the air distribution units;

[0014] The heavy cooler body is a vertical shell, and the top of the heavy cooler body is provided with a feeding port and an exhaust port, and the bottom of the heavy cooler body is provided with a discharging port.

[0015] The heavy cooler body is provided with a material fluidization section and a gravity cooling section from top to bottom.

[0016] The gravity cooling section is provided with a heat exchanger assembly connected with a heat exchange medium supply system, and the heat exchange medium supply system is used for supplying refrigerant to the heat exchanger assembly of the gravity cooling section.

[0017] The gas distribution assembly comprises a fluidization air gas distribution assembly arranged in the material fluidization section.

[0018] The fluidization air gas distribution assembly is connected with a gas supply system, and is used for introducing dry gas into the heavy cooler body, so that the material in the material fluidization section is in a fluidization state, the material entering the material fluidization section is spread in a horizontal direction, so as to ensure that the moisture in the material gap is fully replaced and discharged, and then enters the gravity cooling section. The material layer in the fluidization state can effectively eliminate the feed material cone, so that the bed layer material surface tends to be in the same horizontal plane, and the feed segregation phenomenon is also eliminated; when the material is in the fluidization state, the dry gas can more effectively remove the wet gas in the gap between the material particles, so that the replaced material is in a uniform dry gas environment, and the dew point temperature is much lower than the refrigerant temperature, so that a lower temperature refrigerant can be used to cool the material to improve the cooling efficiency; the high mass transfer rate in the fluidization state can also replace the gas in the capillary pores on the particle surface to a certain extent, so that the moisture in the material is further removed, and deep drying and cooling are achieved.

[0019] The introduced dry gas is preferably dry cold gas, which can replace the dry gas and cool the material at the same time to further improve the cooling efficiency; the dry gas is a gas after removing the moisture, and the dry cold gas is obtained by cooling the dry gas.

[0020] When the fluidization air gas distribution assembly works independently, the fluidization air speed generated by the ventilation volume of the fluidization air gas distribution assembly is 1-6 times the critical fluidization speed calculated according to the average particle size of the material. That is, the fluidization number (the ratio of the fluidization air speed to the critical fluidization speed calculated according to the average particle size of the material) of the material in the material fluidization section is between 1 and 6, so that the material is in a sufficient and uniform fluidization state, the moisture steam contained in the gas in the material gap is removed, and the material flow blockage in the local area is avoided.

[0021] The fluidizing air velocity of the fluidizing air gas distribution assembly refers to the operating air velocity when the material is in a fluidized state, and in the present patent, specifically refers to the operating air velocity formed by the total air volume passing through the material fluidizing section, which is the average air velocity passing through the cross section calculated according to the horizontal net cross-sectional area of the material fluidizing section.

[0022] In the present utility model, the selection of the fluidizing air volume should make the lower limit of the fluidizing air velocity not lower than the critical fluidizing velocity calculated according to the average particle size of the material. Specifically, the lower limit of the fluidizing air velocity is to ensure that the material is in a fluidized state to perform sufficient loosening, flowing, mutual mixing and other movements, so as to eliminate the feeding cone and make the upper surface of the material layer generally at the same level, so that the material layer is generally in a fluidized boiling state, thereby avoiding the lowest operating air velocity that can prevent local material flow from being blocked. The upper limit of the fluidizing air velocity is the maximum air velocity for maintaining stable fluidization of the material layer and preventing excessive entrainment, which can be considered by referring to the upper limit of the operating air velocity of a general fluidized bed.

[0023] From the purpose of making the material in a fluidized and flowing state to eliminate the feeding cone, it can be achieved within a certain range when the operating air velocity is from low to high and approaches the critical fluidizing velocity (for example, for 70% lysine granulation products, the operating air velocity can be basically eliminated when it is 0.7-1 times the critical fluidizing velocity calculated according to the average particle size). However, such local and insufficient fluidization cannot meet the requirements of the present utility model. Because most industrial products have a certain particle size distribution range, the average particle size is uniformly used to calculate the critical fluidizing velocity in engineering, and the range of the operating air velocity (i.e., the actual value of the air velocity during production operation) is determined accordingly. In the present utility model, when the operating air velocity is determined according to the average particle size, for materials with a wide particle size distribution, the fluidization number is below 1 but close to 1, a small part of the material below the average particle size is already in a bubbling fluidization state, and particles with a larger particle size are still in a stationary state. Such local fluidization area is randomly distributed on the entire cross section of the box. In the feeding cone area at the upper part of the material layer, the feeding cone can be basically eliminated under the action of the material pile itself gravity due to the driving of the rising bubbles and flowing particles, so as to make the bed layer tend to be substantially horizontal. However, due to the reasons such as air flow short circuit, local material flow blockage caused by the so-called "local fluidization" or "semi-fluidization", and the structure of uneven distribution of air distribution holes (only distributed at the gas distribution pipe, and the gas distribution pipe is a material flow passage), the humid air in the unfluidized area is more difficult to discharge. The existence of the material moisture absorption and caking characteristics makes the material in the unfluidized area more prone to moisture absorption, caking or scarring. Therefore, in the present utility model, it is not desirable for the operating air velocity to be below the critical fluidizing velocity calculated according to the average particle size.

[0024] The spacing distance of the gas distribution pipe of the fluidizing air gas distribution assembly, the number, shape and spacing distance of the air distribution holes, the opening rate of the air distribution holes (i.e. the ratio of the opening area to the area of the box cross section where the gas distribution pipe is located) are specially designed according to the required ventilation volume, the shape of the box cross section or the distribution of the feeding port, etc., to ensure that the gas is uniformly distributed in the whole cross section of the box and the material is smoothly moved downward from the material flow channel between the gas distribution pipes.

[0025] The utility model discloses preferably, the gravity cooling section sets up multilayer heat exchanger subassembly from top to bottom, and each layer heat exchanger subassembly forms a layer cooling section, and the temperature of the refrigerant of each layer heat exchanger subassembly reduces from top to bottom in turn.

[0026] a. The dry powder and granular material generally contains a small amount of moisture and has certain hygroscopicity. In the balanced state, the material at a certain temperature corresponds to the critical relative humidity of the gas in a certain inter-particle gap and the corresponding critical dew point temperature. When the relative humidity value or the dew point temperature of the gas is higher than the critical value, the moisture will migrate from the gas to the material, and the material will absorb moisture. In the gravity cooling section, the material layer can be regarded as a fixed bed that slowly moves along the fixed flow channel in the aerated state. As the material moves downward, the material temperature gradually decreases, and the corresponding critical relative humidity value and critical dew point value gradually decrease. The material at the end (lower end) of the different layer cooling sections is cooled to a certain temperature, which requires the refrigerant temperature of each layer cooling section to be higher than a certain temperature corresponding to it to ensure that the relative humidity of the gas environment around the particles and the dew point temperature are lower than the critical value, avoiding moisture absorption of the material.

[0027] When dry air with different dehumidification degrees is introduced into different layer cooling sections, it is necessary to prevent the gas near the heat exchange wall from being cooled to a temperature close to the wall temperature, which will cause the relative humidity to rapidly increase to the saturated state and condense on the wall, while meeting the condition that the material does not absorb moisture, to avoid the occurrence of moisture absorption, caking or scarring on the heat exchange wall or in the local material layer near the wall.

[0028] If the uniform temperature refrigerant is connected in parallel into each layer heat exchanger assembly, the temperature difference between the material and the refrigerant in the upper layer to the middle layer cooling section is too large, based on the above reasons, the probability of moisture absorption and scarring is larger; when the refrigerant flows from bottom to top in series, due to the low heat transfer speed between the material layer and the wall surface and the large refrigerant flow, the temperature rise of the refrigerant through the single layer heat exchanger assembly is still low, and the temperature difference between the material and the refrigerant is also large, so the probability of moisture absorption and scarring is still large. In order to avoid this phenomenon, the gravity cooling section is divided into multiple cooling sections, i.e. multiple layer heat exchanger assemblies, different temperature refrigerants are respectively introduced, the material temperature is high at the inlet of the heavy cooler body, the higher temperature refrigerant is introduced into the heat exchanger assembly, and the lower refrigerant temperature is used as the material temperature decreases, so that the temperature difference between the material and the refrigerant is limited to a certain range, and the phenomenon is avoided.

[0029] b. Different temperature refrigerants are introduced into each layer heat exchanger assembly, ordinary refrigerants with lower cost are used at higher material temperature, for example, circulating water provided by public engineering in the factory, and higher cost deep cooling water refrigerants are used at lower material temperature, so that the production cost is saved.

[0030] Preferably, the heat exchanger assembly of each layer adopts an independent heat exchange medium supply system, and the heat exchange medium supply system can independently control the flow and / or temperature of the refrigerant in the heat exchanger assembly connected thereto. Each layer heat exchanger assembly is provided with an independent refrigerant supply system, and the flow and temperature of the refrigerant can be independently adjusted. The purpose is that the refrigerant temperature can be flexibly adjusted to ensure that the refrigerant temperature is higher than the temperature at which the material absorbs moisture and sticks, and scarring on the surface of the cooler, i.e. the heat exchanger assembly, is avoided. The flow of the corresponding refrigerant of each heat exchanger assembly is controlled by an independent pump body, so that the corresponding refrigerant of each heat exchanger assembly can work at a large flow, the temperature difference between the inlet and outlet of the refrigerant is reduced, the heat transfer temperature difference between the refrigerant and the material is increased, and the cooling efficiency is improved.

[0031] Preferably, the gas distribution assembly further comprises a replacement air gas distribution assembly arranged in the gravity cooling section.

[0032] The replacement air gas distribution assembly is connected with the gas supply system and is used for introducing dry gas into the heavy cooler body, so that the material layer is in an aerated state and the gas in the gap between the particles is replaced, the moisture evaporated (volatilized) in the gas and the particles is carried away, the relative humidity and dew point temperature of the gas environment in which the particles are located are reduced, so that lower temperature refrigerant can be used to cool the material; the material in the aerated state can maintain good fluidity, so that the material is in an overall flowing state in the corresponding cooling section; the dry gas is preferably dry cold gas, which can also cool the material and improve the cooling efficiency.

[0033] The operation wind speed generated by the ventilation volume or the sum of the ventilation volumes of the replacement air distribution assembly is the average wind speed passing through the cross section calculated according to the horizontal net cross-sectional area of the gravitational cooling section, and the operation wind speed is 0-0.5 times the critical fluidization speed calculated according to the average particle size of the material;

[0034] When the fluidization air distribution assembly and the replacement air distribution assembly work simultaneously, the fluidization wind speed generated by the ventilation volume of the fluidization air distribution assembly calculated alone is not less than 0.7 times the critical fluidization speed calculated according to the average particle size of the material; and the fluidization wind speed generated by the sum of the ventilation volumes of the fluidization air distribution assembly and the replacement air distribution assembly is not less than 1.2 times the critical fluidization speed calculated according to the average particle size of the material.

[0035] After the material passes through the upper fluidization section, most of the humid gas has been replaced out of the material gap, and the material is in a relatively dry gas environment, at this time, only a small amount of dry gas is needed to be introduced into the heavy cooler body through the replacement air distribution assembly to take out a small amount of moisture volatilized from the material; when selecting a plurality of dry gases with different drying degrees, the lower replacement air distribution assembly can select a gas that is drier than the dry gas introduced by the upper air distribution assembly, to further reduce the dew point of the gas environment in the material gap, and correspondingly, a lower temperature coolant can be used. The dry gas introduced not only takes out the moisture vapor, but also improves the flowability of the material.

[0036] The maximum operation wind speed generated by the ventilation volume or the sum of the ventilation volumes of the gravitational cooling section is as low as possible when meeting the operation requirements, and the fluidization number is preferably between 0 and 0.5, on the one hand, the resistance of the gas passing through the material layer is very low when the gas speed is low, and the power consumption of the gas pressurization is small, on the other hand, when the operating gas speed is close to the critical fluidization gas speed, the so-called "local fluidization" or "semi-fluidization" phenomenon occurs, causing gas short circuiting and other defects, which intensifies the gravity flow blockage in the unfluidized area, and thus reduces the cooling effect;

[0037] Although the gravitational cooling section is provided with a plurality of replacement air distribution assemblies, according to production needs, the replacement air distribution assemblies can be not opened, one layer opened, multiple layers opened, or all opened, when the replacement air distribution assembly is not opened, the ventilation volume is 0; when one layer of the replacement air distribution assembly is opened, the ventilation volume is controlled so that the fluidization number is ≤0.5; when multiple layers of the replacement air distribution assembly are opened, the sum of the ventilation volumes is controlled so that the fluidization number is ≤0.5. Because no other gas discharge structure is arranged in the middle of the material layer in the present utility model, the gas always moves upward from the bottom to the top exhaust port, and the material layer at the upper part of the body always receives all the ventilation volume from the lower part thereof.

[0038] Each layer of the heat exchanger assembly is provided below with a layer of replacement air distribution assembly.

[0039] The multiple layers of heat exchanger assemblies are arranged from top to bottom, and a layer of displacement air distribution assembly is arranged below each layer of heat exchanger assembly, and the technical significance is as follows:

[0040] a. During the start-up stage, a certain amount of "bottom material" is needed to completely bury the heat exchanger assembly in the material layer, so as to start normal production. During the process of feeding the "bottom material", the discharge device is in a state of stopping or slow discharge. With the feeding process, the material layer gradually rises. When the material layer is within the height range of the bottom layer of heat exchanger assembly, the displacement air distribution assembly below it is started. When the material layer rises to the height range of the second last layer of heat exchanger assembly, the second last displacement air distribution assembly is started, and the second last displacement air distribution assembly is closed or reduced. In turn, when the material reaches the running material level, the highest fluidization air distribution assembly is started, and the system enters normal operation. This operation ensures that the moisture in the material is fully and reliably replaced by dry gas during the start-up to stable operation.

[0041] b. In the shutdown stage, the reverse sequence is adopted, and the lower position gas distribution assembly is started and the higher position gas distribution assembly is closed as the material layer decreases. This operation ensures that the moisture in the material is fully and reliably replaced by dry gas during shutdown.

[0042] c. In normal production, the displacement air distribution assembly can be selected not to be started, one layer, multiple layers or all layers according to the material properties and operation requirements. For example, for some materials, a small amount of moisture will still evaporate when the material temperature is higher in the upper region of the cooling section, and the moisture evaporation will stop when the material temperature is lower in the middle and lower regions of the cooling section. At this time, the upper gas distribution assembly should be started without starting the lower gas distribution assembly. Some materials need to be cooled to a very low temperature, and more dry gas needs to be supplemented to adapt to the lower temperature coolant. At this time, only the lower gas distribution assembly can be started. Some materials have poor flowability, and the appropriate aeration state should be maintained during the entire cooling process to increase the flowability. At this time, all gas distribution assemblies can be started to pass a small amount of dry gas. For materials with good flowability and no steam separation during the entire process, even no aeration is possible.

[0043] When multiple gas distribution assemblies are started, the displacement air flow of the cooling section in the upper position is the sum of the air flow of all started gas distribution assemblies below, and the fluidization air flow of the material fluidization section in the upper position is the sum of the air flow of all gas distribution assemblies below. The actual operating air speed of the material layer (the fluidization air speed in the fluidization section) is generated by all air flows through the cross section of the material layer.

[0044] d.In actual application, for the material with less obvious moisture absorption and scabbing characteristics, the gas distribution assembly (including the fluidizing air gas distribution assembly and the displacement air gas distribution assembly) can be sequentially connected with the gas with different drying degrees from top to bottom, as long as the dew point temperature of the gas is lower than the inlet temperature of the refrigerant of the cooling section by a certain degree, so as to further save the energy consumption and equipment cost for gas dehumidification. The drying degree of the dry gas should ensure that the wall surface of the heat exchanger assembly where the refrigerant with the lowest temperature in the cooling section of the layer is not condensed, and at the same time, ensure that the material is not absorbed, caked or scabbed when the wall surface of the heat exchanger assembly where the refrigerant with the lowest temperature is cooled.

[0045] Preferably, the material fluidization section is provided with the heat exchanger assembly connected with the heat medium supply system;

[0046] The heat medium supply system is used for providing the refrigerant for the heat exchanger assembly in the material fluidization section. By arranging the heat exchanger assembly in the material fluidization section, the heat exchanger assembly and the material in the fluidization state are heat-exchanged, so that the heat transfer coefficient can be significantly improved, and the cooling efficiency is improved. In addition, by making the material in the fluidization state, the wall surface of the heat exchanger assembly can be continuously scoured by the material, so that the surface scabbing of the top heat exchanger assembly is further avoided, and the heat exchange efficiency is improved.

[0047] Preferably, each layer of the heat exchanger assembly comprises a plurality of heat exchangers arranged in series from top to bottom, and a gas distribution assembly connected with the gas supply system is arranged between two adjacent heat exchangers, so as to reduce the height of the fluidizing air or the displacement air passing through the material layer, thereby reducing the non-uniformity of the gas distribution and reducing the resistance of the gas passing through the material layer.

[0048] Preferably, the utility model also includes auxiliary bunker, the import of auxiliary bunker is connected with the discharge port, the export of auxiliary bunker is connected with the feed port. Through setting up auxiliary bunker, be used for in the process of starting up fast filling heavy cooler body box, make the material reach the material level above the heat exchanger assembly, shorten the starting process. And can be used as the temporary storage container when the equipment is overhauled, and the material after cooling is temporarily stored.

[0049] Preferably, the auxiliary bunker is located above the heavy cooler body, and the material can be fed into the heavy cooler body by gravity.

[0050] Preferably, the utility model also includes a material level meter and an adjustable flow discharge device.

[0051] The material level meter is arranged at the top of the heavy cooler body and is used for measuring the material level height in the heavy cooler body.

[0052] The discharger is connected with the discharge port, and is used for adjusting the discharging speed of the material, so as to control the material level height in the heavy cooler body.

[0053] Preferably, the gas supply system comprises a gas dehumidification device and / or a cooling device, and the heat exchange medium supply system comprises a fluid cooling device.

[0054] The gas dehumidification device is used for removing the moisture in the gas to obtain dry gas, the gas cooling device is used for controlling the temperature of the dry gas, and the fluid cooling device is used for controlling the temperature of the refrigerant, so as to avoid moisture absorption, caking or scabbing of the material on the wall of the heat exchanger.

[0055] Preferably, the air distribution unit comprises gas distribution pipes, and air distribution holes are arranged below the gas distribution pipes.

[0056] The air distribution holes are arranged in rows along the axial direction of the gas distribution pipes and are spaced apart from each other, and at least one row of air distribution holes is arranged below each gas distribution pipe. One or more air distribution holes are arranged in the lower half of each gas distribution pipe along the axial direction, and the air distribution holes are used to send the gas in the pipe to the material channel inside the heavy cooler body. The arrangement mode of the gas distribution pipes and the hole arrangement mode of the pipe wall can ensure that the gas is uniformly distributed to the entire cross section of the heavy cooler body shell and passes through the material layer upwards. The cross-sectional shape of the gas distribution pipe can be circular, oval, rhombic, oblong or other shapes, and the shape of the air distribution hole can also be a strip-shaped gap.

[0057] Preferably, the gas distribution pipe is a straight pipe.

[0058] Preferably, the extension direction of the gas distribution pipe is perpendicular to the extension direction of the heat exchange pipe or heat exchange plate in the heat exchanger assembly in the horizontal direction. The perpendicular arrangement of the extension direction of the gas distribution pipe and the extension direction of the heat exchange pipe or heat exchange plate in the dry heat exchanger assembly or the cooling heat exchanger assembly in the horizontal direction is beneficial to more uniform distribution of the gas in the heat exchange pipe or heat exchange plate area, and avoids local airflow shortage, which causes poor material fluidization or local blockage.

[0059] The fluidization air gas distribution assembly is preferably arranged in the form of a plurality of layers, and the opening rate of the air distribution hole below the feed inlet of the uppermost layer fluidization air gas distribution assembly is greater than the opening rate of other positions.

[0060] The gas distribution pipe of the fluidization air gas distribution assembly can be adjusted, for example, the gas distribution pipe corresponding to the pipe arrangement region of the tip region of the material cone near the feed inlet can be arranged more densely, and the air distribution hole is opened more, so that the material loosening (or flowing) of the corresponding tip region is more intense even in the insufficient fluidization state, and the material cone is eliminated under the action of gravity, so that the material layer region is basically horizontal.

[0061] The heat exchanger assembly comprises a plurality of heat exchange pipes arranged in the horizontal direction, and the heat exchange pipes are serpentine pipes extending upward and downward.

[0062] The two adjacent serpentine heat exchange pipes are arranged in a staggered manner upward and downward, the number of material distribution and convergence in the flow channel is increased, the disturbance of the material side is increased, the heat transfer coefficient of the material side is increased, the flow of the material is increased, and the slight adhesion phenomenon of the material is also reduced.

[0063] The working principle of the utility model is as follows:

[0064] The dry gas is blown into the shell of the heavy cooler body through the fluidization air gas distribution main pipe, so that the material above the fluidization air gas distribution pipe is in a fluidization state, and the characteristics of the gas-solid fluidization phenomenon are used to pretreat the material from the drying process as follows:

[0065] a. Eliminate the segregation phenomenon of the feed cone and the feeding process, and make the material uniformly distributed in the cross section of the heavy cooler body.

[0066] Theoretically, it is always desirable that the material moves downward in the tank of the gravity flow type indirect cooler (hereinafter referred to as the heavy cooler) in a bulk flow manner, so that the material on the entire cross section experiences the same cooling process and obtains uniform cooling depth. However, the actual powder or granular material always has a certain particle size distribution range. When the material is freely poured from the feed inlet to the stationary heat exchanger assembly or the upper part of the material, a conical material accumulation area, i.e. the feed cone, is formed. After the formation of the feed cone, the subsequent particles will appear the phenomenon that the large particle size material is enriched in the periphery of the cone, and the small particle size and powder material is enriched in the central part, i.e. the particle segregation phenomenon. The weight of the feed cone and the impact force of the feed form uneven pressure on the material below, causing the material in the central region of the feed cone to move downward at a fast speed and the material around the feed cone to move downward at a slow speed, affecting the uniformity of the bulk flow of the material, thereby causing the cooling depth of the material in different tank cross section regions to be different. Since the material moving downward in the heavy cooler in a bulk flow manner has the same cooling time, when the segregation phenomenon occurs, the phenomenon of uneven particle size distribution of the material occurs on the cross section of the tank body of the heavy cooler, and the cooling speed of the coarse particles is slower than that of the fine particles. This uneven cooling speed will cause the temperature of the material around the feed cone to be higher than that of the material in the central region, thereby exacerbating the cooling temperature difference.

[0067] The utility model discloses a material fluidization section is arranged on the heavy cooler body, and in the fluidization state, the material has the characteristics similar to fluid, and the feed cone is automatically eliminated, and a horizontal fluidization bed upper surface is formed, thereby making the material pressure on the entire cross section of the heavy cooler body be uniform, which is beneficial to the bulk flow of the material from top to bottom in the tank of the gravity cooling section, and increases the uniformity of the cooling time of the material in the heavy cooler body cross section. Further, in the fluidization state, the particle size distribution of the material in the horizontal direction is uniform, and the segregation phenomenon of the material does not exist, thereby ensuring that the material enters the subsequent cooling process with uniform particle size distribution and eliminating the uneven cooling caused by the different particle size distribution of the feed.

[0068] b. The wet hot gas in the gap of the material particles is replaced efficiently, and the material is pre-cooled and uniformly treated.

[0069] The powder or granular material has certain porosity, and the particle gap of the material after drying treatment is usually filled with humid hot gas, which can be common air or inert gas such as nitrogen, and the humidity can be common water vapor or steam of other volatile components such as methanol vapor. The relative humidity of the humidity in the gas is very low at high temperature, but the relative humidity becomes larger after cooling, and the humidity is more easily absorbed by the particles, thereby increasing the humidity in the particles, that is, the material absorbs moisture. When the temperature of the humid gas drops below the dew point temperature of the humidity, the humid gas is more likely to condense on the surface of the particles and the wall surface of the heat exchanger, especially when the temperature of the wall surface of the heat exchanger and the surrounding area is very low, the humid gas is more likely to condense, which directly causes the material to be caked or the wall surface of the heat exchanger to be scabbed, so the humid hot gas of the material that is easy to absorb moisture must be replaced to be in a dry gas environment, and the fluidization gas can play such a role.

[0070] Further, in the fluidized state, the contact efficiency of the particles and the fluidization gas is high, the gas around each particle can be fully replaced, the high mass transfer rate in the fluidized state can replace the gas in the capillary pores on the surface of the particles to a certain extent, and the heat transfer efficiency is also high, so that the heat energy of the low-temperature fluidization gas is fully utilized to reduce the temperature of the feed, eliminate the temperature and humidity difference between the particles with different humidity and different particle size, and better cooling and moisture uniformization effect is achieved.

[0071] In addition, the gas flow of the fluidization air gas distribution assembly of the utility model makes the corresponding material layer in the fluidized bed, and the effect of eliminating the feeding cone and the material segregation is basically irrelevant to the size and shape of the cross section of the bed, so a larger cross-sectional area can be used to put in a larger heat exchanger assembly or a plurality of heat exchanger assemblies with different combination modes, without worrying about the influence of non-integral flow and uneven particle size distribution caused by the increase of the height of the feeding cone on the uniformity of cooling, so that a smaller height-diameter ratio (for a rectangular shell, it can be described as a height-width ratio or a height-length ratio, or as a height-cross-sectional area ratio) can be used to obtain larger material processing capacity, or in the case that the feeding amount is the same or the material cooling temperature difference is the same, a lower equipment height is used, and the corresponding plant height or the secondary lifting height of the material is reduced, thereby increasing the investment or energy consumption.

[0072] Compared with the prior art, the utility model has the advantages that the utility model provides a gravity flow type indirect cooler, which indirectly exchanges heat and cools the dried material through the heat exchanger assembly, avoids contact between the material and the external air, and avoids abrasion of the material particles.

[0073] The utility model discloses a material fluidization section and gravity cooling section are set from top to bottom in the vertical heavy cooler body, through setting the fluidization wind gas distribution subassembly connected with the gas supply system in material fluidization section, utilize fluidization wind gas distribution subassembly and pass into dry gas to heavy cooler body, make material of material fluidization section present flow state condition, form a flow state material layer in the upper region of the material layer of overall gravity type slow movement in heavy cooler body, thereby make the material that the feed inlet sent spreads evenly on horizontal direction (i. e. heavy cooler body cross section) and mixes evenly with the material below, eliminate the uneven distribution of particle size of material in heavy cooler body cross section, guarantee the overall uniformity of material and make material be cooled evenly when passing through gravity cooling section by heat exchanger subassembly, thereby avoid the caking problem in the transportation or storage process caused by uneven material cooling.

[0074] In addition, utilize fluidization wind gas distribution subassembly and pass into dry gas to heavy cooler body, make material of material fluidization section present flow state condition, can make material be further deeply dried under flow state condition while rapidly taking away the wet hot gas carried by material, make material be in dry gas environment, effectively avoid the scab of heat exchanger subassembly wall surface and material caking, and realize the homogenization of material moisture in the same cross section of heavy cooler body, further help heat exchanger subassembly to adopt lower temperature refrigerant, improve the cooling efficiency of material, further avoid the caking problem in the transportation or storage process caused by the uneven moisture of material and the temperature difference between material and environment. BRIEF DESCRIPTION OF DRAWINGS

[0075] Figure 1 It is the structure schematic diagram of gravity flow type indirect cooler of the utility model embodiment 1;

[0076] Figure 2 It is the structure schematic diagram of gravity flow type indirect cooler of the utility model embodiment 2;

[0077] Figure 3 It is the structure schematic diagram of gravity flow type indirect cooler of the utility model embodiment 3;

[0078] Figure 4 It is the position relation schematic diagram of gas distribution subassembly and heat exchanger subassembly;

[0079] Figure 5 It is the structure schematic diagram of gas distribution pipe longitudinal section direction;

[0080] Figure 6 It is the structure schematic diagram of gas distribution pipe cross section direction;

[0081] Figure 7 It is the structure schematic diagram of the air distribution hole of the utility model embodiment;

[0082] Figure 8 is a structural schematic view of a tube heat exchanger;

[0083] Figure 9 is a structural schematic view of a plate heat exchanger;

[0084] Figure 10 is a structural schematic view of a heat exchange plate provided with a gas exchange hole;

[0085] Figure 11 is a partial structural schematic view of the gravity flow type indirect cooler according to Embodiment 4 of the present application;

[0086] In the figure, 1 is a heavy cooler body, 2 is a fluidization wind gas distribution assembly, and 3 is a heat exchanger assembly.

[0087] 1000 is a first material passage, 2000 is a wind distribution unit, and 3000 is a second material passage.

[0088] 101 is a feeding port, 102 is an exhaust port, and 103 is a discharging port.

[0089] 100 is a material fluidization section, and 200 is a gravity cooling section.

[0090] 4 is a replacement wind gas distribution assembly, 5 is an auxiliary bin, 6 is a material level meter, 7 is a discharger, 8 is a gas distribution pipe, 81 is a wind distribution hole, and 9 is an upper surface of a material layer.

[0091] 300 is an inlet distribution main pipe, 400 is an outlet distribution main pipe, and 500 is a first connecting pipe.

[0092] 600 is a gas distribution main pipe, 700 is a second connecting pipe, 801 is a heat exchange pipe, and 802 is a heat exchange plate. DETAILED DESCRIPTION

[0093] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings.

[0094] In the present application, the definition of a net cross section is as follows: on any horizontal cross section of the bed layer, i.e. the material fluidization section or the gravity cooling section, the cross-sectional area of the material flow passage after deducting the cross-sectional area occupied by the heat exchanger assembly.

[0095] The calculation method of the critical fluidization velocity is as follows: the calculation formula given in the book “Fluidization Drying Process and Equipment” published by Science Press in 1996 and written by Tong Jingshan, page 166.

[0096] Embodiment 1

[0097] As Figure 1 and Figure 4As shown in the drawings, a gravity flow indirect cooler comprises a heavy cooler body 1, a gas distribution assembly, a heat exchanger assembly 3, a gas supply system and a heat exchange medium supply system (not shown in the drawings).

[0098] The heat exchanger assembly 3 is a plate heat exchanger or a tube heat exchanger, and first material passages 1000 are arranged vertically through the heat exchanger plates 802 or the heat exchanger tubes 801.

[0099] The gas distribution assembly is horizontally arranged in the heavy cooler body 1 and comprises air distribution units 2000 arranged at intervals along the cross section of the heavy cooler body 1 and second material passages 3000 arranged between the air distribution units 2000, the second material passages 3000 being vertically through passages.

[0100] As shown in Figure 4 , Figure 8 and Figure 9 , the air distribution unit 2000 comprises a gas distribution pipe 8, a plurality of gas distribution pipes 8 are arranged at intervals on the same horizontal plane and are arranged in parallel at intervals, as shown in Figure 5 The gas distribution pipe 8 is provided with air distribution holes 81 below, as shown in Figure 7 (a), the gas distribution pipe 8 is provided with a row of air distribution holes 81 below, as shown in Figure 7 (b), the gas distribution pipe 8 is provided with three rows of air distribution holes 81 below to increase the flow.

[0101] As shown in Figure 4 , Figure 5 and Figure 6 , the extension direction of the gas distribution pipe 8 is perpendicular to the extension direction of the heat exchanger tubes 801 or the heat exchanger plates 802 in the heat exchanger assembly 3 in the horizontal direction, so as to ensure that the first material passages 1000 and the second material passages 3000 are perpendicular to each other and communicate with each other. The arrangement mode of the gas distribution pipe 8 and the mode of the holes on the pipe wall are used to ensure that the gas is uniformly diffused to the entire shell cross section of the heavy cooler body 1 and passes through the material layer upward; a gas distribution main pipe 600 is arranged outside the shell of the heavy cooler body 1, and a second connecting pipe 700 connects the gas distribution pipe 8 and the main pipe.

[0102] As shown in Figure 1 , the heavy cooler body 1 is a vertical shell, the heavy cooler body 1 is provided with a feed inlet 101 and an exhaust outlet 102 at the top, and the heavy cooler body 1 is provided with a discharge outlet 103 at the bottom.

[0103] Specifically, the heavy cooler body 1 is provided with a material fluidization section 100, a gravity cooling section 200 and a discharge section from top to bottom. The upper half of the fluidization drying section is also the feeding section. The feeding section generally has a shell with a uniform rectangular cross section from top to bottom. The top of the feeding section shell is provided with one or more feeding ports 101 for adding the powder and particle materials to be treated. The top of the feeding section shell is provided with an exhaust port 102 for discharging gas. The internal space of the feeding section shell is used to accommodate the material, which is usually filled with a part of the shell in the working state. Under the action of fluidization, there is a clear material layer upper surface 9. There is a certain height of space above the upper part of the material, and small particles carried into the tail gas re-settle to the material layer under the action of gravity within this height. The bottom of the feeding section shell is open, generally equal to the cross section of the feeding section shell, for connecting with the feeding end of the material fluidization section 100, or the feeding section itself is the upper half of the material fluidization section 100, that is, there is a certain residual space above the material layer upper surface of the material fluidization section 100. The feeding section shell is provided with a level meter for measuring the level height and electrically transmitting to the control system.

[0104] As shown in Figure 1 , the heavy cooler body 1 is provided with a material fluidization section 100 and a gravity cooling section 200 from top to bottom.

[0105] The gravity cooling section 200 is provided with a heat exchanger assembly 3 connected with a heat exchange medium supply system for providing coolant to the heat exchanger assembly 3 of the gravity cooling section 200.

[0106] The gas supply system includes a gas dehumidification device and / or a cooling device, and the heat exchange medium supply system includes a fluid cooling device (not shown in the embodiment).

[0107] The gas dehumidification device is used to remove moisture in the gas to obtain dry gas, the gas cooling device is used to control the temperature of the dry gas, and the fluid cooling device is used to control the temperature of the coolant to avoid moisture absorption, caking or scarring on the heat exchanger wall of the material.

[0108] The heat exchanger assembly 3 is a tubular heat exchanger or a plate heat exchanger. The outer space of the heat exchanger assembly 3 is a material channel, and the inner space is a coolant fluid channel, which are separated by the heat exchange wall of the heat exchanger assembly 3, and heat is transferred through the wall.

[0109] As shown in Figure 8As shown, when the heat exchanger assembly 3 is a tube heat exchanger, the heat exchanger assembly 3 includes a plurality of heat exchange tubes 801 arranged in the horizontal direction and spaced apart from each other, arranged in the shell of the corresponding regenerator body 1 of each cooling section, for cooling the powdery material. The heat exchange tube is a serpentine tube structure extending upward and downward, each serpentine tube including horizontally arranged tube portions spaced apart from each other from top to bottom and combined with bent tube portions connecting adjacent horizontal tubes in sequence, and the horizontal tubes at the bottom and top of the serpentine tube extend to the outside of the regenerator body 1 shell and are connected with the coolant inlet or outlet distribution header; two adjacent serpentine heat exchange tubes are arranged in staggered arrangement upward and downward; the serpentine tube group formed thereby is fixed by a plurality of partitions and a panel, and combined into an independent heat exchanger assembly; the heat exchanger assembly is fixed on the regenerator body 1 shell by a fixing member (not shown in the figure), wherein the panel serves as a fixing flange and is connected with the regenerator body 1 shell by a sealing gasket, bolts and other fixing members (not shown in the figure), and the heat exchanger assembly can be conveniently pulled out and installed from the side of the regenerator body 1 shell during maintenance.

[0110] As shown in Figure 9 , when the heat exchanger assembly 3 is a plate heat exchanger, the plate heat exchanger is provided with a row of point-shaped welding areas and a line-shaped welding seam arranged in an alternating manner upward and downward, the pillow-shaped expansion area formed between the point-shaped welding areas serves as a passage for the heat exchange medium, and the surrounding area of each local welding area is raised to form a generally bowl-shaped pit, and the line-shaped welding seam arranged in an alternating manner upward and downward forms a serpentine path for the heat exchange medium. The pits of adjacent rows (or columns) are usually arranged in a staggered manner to increase the disturbance in the flow process of the internal fluid and the external powdery material, and the overall flow mode of the serpentine path avoids internal fluid short circuiting, increases the flow length, and improves the flow speed; the above measures can significantly improve the flow and heat transfer characteristics of the fluid and the material.

[0111] When the heat exchanger assembly 3 is a plate heat exchanger, in order to improve the flow of gas inside the heat exchanger assembly 3, as shown in Figure 10 , a gas exchange hole can be arranged on the heat exchange plate 802 of the plate heat exchanger for the gas to pass through, increasing the gas flow between different heat exchange plates to stabilize the gas flow state.

[0112] As shown in Figure 8 , Figure 9As shown, the heavy cooler body 1 shell outside is equipped with the inlet and outlet distribution manifold 300 and 400 of refrigerant, and the first connecting pipe 500 for connecting the heat exchanger assembly 3 and the refrigerant distribution manifold together, the refrigerant enters each heat exchanger assembly 3 from the inlet distribution manifold 300, and after indirect heat exchange with the material in the heat exchanger assembly 3, it is collected into the outlet distribution manifold 400; the refrigerant can enter the heat exchanger assembly 3 from the lower distribution manifold and be discharged from the upper distribution manifold, that is, the inlet distribution manifold 300 is arranged below the outlet distribution manifold 400, thereby forming a countercurrent heat exchange mode opposite to the flow direction of the material, obtaining a higher heat exchange temperature difference and faster cooling of the material, and the material cooling process can also be carried out gently because the heat exchange temperature difference is low.

[0113] The gas distribution assembly includes a fluidization air gas distribution assembly 2 arranged in the material fluidization section 100.

[0114] As shown in Figure 1 and Figure 4 In this embodiment, the fluidization air gas distribution assembly 2 is located at the upper part of the heat exchanger assembly 3, a plurality of gas distribution pipes 8 are distributed on the same horizontal plane and are uniformly arranged in parallel with each other, and a plurality of rows of holes are opened in the lower half of each gas distribution pipe 8 of the fluidization air gas distribution assembly 2 along the length direction, for sending the gas in the pipe to the material passage inside the heavy cooler body 1 box, to ensure that there is sufficient gas flow to make the material in a fluidized state.

[0115] The fluidization air gas distribution assembly 2 is connected with a gas supply system, for introducing dry gas into the heavy cooler body 1, to make the material in the material fluidization section 100 present a fluidized state, to make the material entering the material fluidization section 100 spread horizontally, to make the bed layer material surface tend to be the same level, to ensure that the moisture in the material gap is fully replaced and discharged before entering the gravity cooling section 200. The present application can make the material uniformly spread horizontally by using the similar liquid characteristics of fluidization, and can more fully replace the moisture by using the high heat and mass transfer characteristics of fluidization, so that the moisture of coarse and fine particles is uniformized, which cannot be achieved when the material is not in a fluidized state.

[0116] Preferably, the opening rate of the air distribution hole 81 of the uppermost fluidization air gas distribution assembly 2 below the feed inlet 101 is greater than that of other positions, to improve the uniform distribution effect of the material at the lower part.

[0117] In the embodiment, the fluidization air distribution assembly 2 is horizontally arranged in the material fluidization section 100 to fluidize the material above the fluidization air distribution assembly 2 and form a fluidized bed with a certain height (for example, 500-1000 mm). In order to achieve better cooling effect, the fluidization air distribution assembly 2 can also introduce dry cooling gas into the heavy cooler body 1. In addition, in order to improve the effect of deep drying, the fluidization air distribution assembly 2 can also introduce dry hot air with a temperature higher than the material temperature or dry air with a temperature equivalent to the material temperature into the heavy cooler body 1 to heat or keep warm the material while fluidizing the material.

[0118] In the embodiment, the cross-sectional area of the material fluidization section 100 is uniform, the fluidization air speed generated by the ventilation volume of the material fluidization section is the average air speed passing through the cross section calculated according to the horizontal net cross-sectional area of the material fluidization section 100, and the fluidization air speed when the fluidization air distribution assembly 2 works independently is 1-6 times the critical fluidization speed calculated according to the average particle size of the material.

[0119] Preferably, the fluidization state of the material is bubbling fluidization.

[0120] The gravity cooling section 200 is provided with multiple layers of heat exchanger assemblies 3 from top to bottom, each layer of heat exchanger assembly 3 forms a cooling section, as shown in the figure, three layers of cooling sections are arranged in the embodiment. Figure 1

[0121] As shown in the figure, the gas distribution assembly further includes a displacement air distribution assembly 4 arranged in the gravity cooling section 200, which has the same structure and arrangement as the fluidization air distribution assembly. Figure 1

[0122] The displacement air distribution assembly 4 is connected with the gas supply system to introduce dry gas into the heavy cooler body 1.

[0123] Each layer of heat exchanger assembly 3 in the gravity cooling section 200 is provided with a layer of displacement air distribution assembly 4 below.

[0124] In the embodiment, since the material in the gravity cooling section 200 is uniformly distributed, it is only necessary to keep the material in an aerated state, therefore, the lower half of each gas distribution pipe 8 in the displacement air distribution assembly 4 is provided with a row of air holes with the same size along the length direction.

[0125] Since the maximum ventilation volume of the fluidization air distribution assembly 2 is greater than that of the displacement air distribution assembly 4, the opening rate of the fluidization air distribution assembly 2 is greater than that of the displacement air distribution assembly 4.

[0126] ​​The cross-sectional area of the gravity cooling section 200 is uniform, and when the displacement air distribution assembly 4 is partially or fully working, the operation air speed generated by the air volume or the sum of the air volume of the displacement air distribution assembly 4 is the average air speed passing through the cross section calculated according to the horizontal net cross-sectional area of the gravity cooling section 200, which is 0-0.5 times the critical fluidization speed calculated according to the average particle size of the material. When the fluidization air distribution assembly 2 and the displacement air distribution assembly 4 work simultaneously, the fluidization air speed generated by the air volume of the fluidization air distribution assembly 2 calculated alone is not less than 0.7 times the critical fluidization speed calculated according to the average particle size of the material. The fluidization air speed generated by the sum of the air volume of the fluidization air distribution assembly 2 and the displacement air distribution assembly 4 is not less than 1.2 times the critical fluidization speed calculated according to the average particle size of the material. According to the effect of dry gas displacement and material cooling of the upper material fluidization section 100 and / or the material cooling section, the displacement air distribution assembly 4 can not be opened or can be partially opened, and the air supply amount can be adjusted.

[0127] The temperature of the refrigerant of each layer of heat exchanger assembly 3 decreases from top to bottom, and at the same time, the temperature difference between the refrigerant of the heat exchanger assembly 3 and the material outside the heat exchange wall is also reduced accordingly, so as to reduce the probability of material moisture absorption and caking. For materials with weak moisture absorption and caking characteristics, the temperature difference between the two can also be maintained to improve the cooling efficiency.

[0128] Each layer of heat exchanger assembly 3 uses an independent heat exchange medium supply system, which can independently control the flow and / or temperature of the refrigerant in the connected heat exchanger assembly 3. Each independent heat exchange medium supply system includes a refrigerant heat exchanger, a pump, a circulating water tank, and a corresponding pipeline system.

[0129] As shown in Figure 1 The gravity flow type indirect cooler further comprises an auxiliary bin 5 located above the heavy cooler body 1, the inlet of the auxiliary bin 5 is connected with the discharge port 103, and the outlet of the auxiliary bin 5 is connected with the feeding port 101. The effective loading volume of the auxiliary bin 5 is about the loading volume of the heavy cooler body 1 under normal working condition; before the heavy cooler is stopped, the cooled material is sent into the auxiliary bin 5 through the air bypass, and then quickly fed into the heavy cooler body 1 when the heavy cooler is started, so as to reach the material level above the heat exchanger assembly and shorten the starting process. Moreover, the auxiliary bin 5 can be used as a temporary storage container for storing the cooled material during equipment failure repair.

[0130] As shown in Figure 1 The gravity flow type indirect cooler further comprises a material level meter 6 and a flow-adjustable discharger 7.

[0131] The material level meter 6 is arranged at the top of the heavy cooler body 1 and is used for measuring the material level height in the heavy cooler body 1.

[0132] The discharger 7 is connected with the discharge port 103, and is used to adjust the discharging speed of the material, so as to control the material level in the heavy cooler body 1.

[0133] In the embodiment, the pneumatic conveying equipment is used for feeding, that is, the outlet of the discharger 7 is connected with the feeding equipment of the pneumatic conveying equipment, the air inlet of the pneumatic conveying equipment uses the same parameters as the dry gas, and a return bypass is arranged on the main pipeline of the pneumatic conveying equipment, which is used to feed the auxiliary bin 5.

[0134] The discharger 7 can be any one of various forms such as a rotary air-lock discharge valve, a vibrating discharger, a belt discharger, a single-shaft or multi-shaft screw discharger, etc. The discharger 7 has a driving device and a discharging speed controller. The discharging speed controller receives the electric signal of the material level meter 6 installed on the top of the heavy cooler body 1, and then controls the discharger 7 to adjust the discharging flow, so as to ensure that the upper surface 9 of the material layer is higher than the upper surface of the fluidized gas distribution assembly 2 by a certain height, thereby forming a fluidized material layer with a certain height on the upper part, ensuring that the feeding material is uniform and the wet hot gas carried by the to-be-cooled material is fully replaced, and ensuring that the material will not absorb moisture and scab on the wall of the heat exchanger assembly 3.

[0135] The discharging section is an upper-large and lower-small discharging cone bucket, which is used to receive the powder or granular material falling from the gravity cooling section 200. The upper part of the cone bucket has the same cross section as the shell of the gravity cooling section 200 and is connected together. The cone bucket gradually shrinks from top to bottom and is connected with the discharge port 103 which has the same cross section.

[0136] One or more auxiliary discharging devices such as vibration and knocking are installed on the wall surface of the discharging section, which can assist the flow of the material in the cone bucket through mechanical vibration or knocking. Alternatively, one or more auxiliary discharging devices using compressed gas to impact the material are installed, which can release the compressed gas instantaneously to loosen the material. The auxiliary discharging device can prevent the local hardening or “bridge” of the material and ensure that the material flows out smoothly in an overall manner.

[0137] The gravity flow type indirect cooler also includes supporting, fixing, hoisting, connecting, repairing, observing, detecting and other auxiliary components and structures for supporting, fixing, hoisting, connecting, repairing, observing, detecting and the like. These are required in conventional engineering or equipment design, and will not be described here.

[0138] The method for cooling the material by using the gravity flow type indirect cooler of the embodiment includes the following steps:

[0139] S1, the heat exchanger assembly 3 in the heavy cooler body 1 is completely buried by the material.

[0140] S2, dry gas is introduced into the heavy cooler body 1 by using the gas distribution assembly, so that the material in the material fluidization section 100 is in a fluidized state, ensuring that the material is uniformly distributed in the cross section of the heavy cooler body 1 and enters the gravity cooling section 200 in this uniformly distributed state, and at the same time, the dry gas fully replaces the humid gas between the material particles, taking out the moisture in the humid gas and the moisture separated from the material from the heavy cooler body 1.

[0141] S3, the material is cooled by using the heat exchanger assembly 3 of the gravity cooling section 200, and the coolant inlet temperature of each heat exchanger assembly 3 is controlled to be higher than the material moisture absorption, caking or scabbing temperature on the material side of the corresponding heat exchanger assembly 3.

[0142] The above-mentioned gas distribution assembly includes a fluidization air gas distribution assembly 2 and a replacement air gas distribution assembly 4.

[0143] In step S1, the method for completely burying the heat exchanger assembly 3 in the heavy cooler body 1 by using the material is as follows:

[0144] S11, a gas distribution assembly is arranged at the upper end inside the heavy cooler body 1.

[0145] Before the material to be cooled is cooled, the cooled material is quickly added to the preset height in the heavy cooler body 1 by the auxiliary bin 5, manual feeding or other dry cooling systems in a continuous transfer manner; the preset height is higher than the gas distribution assembly.

[0146] S12, dry gas is introduced by using the gas distribution assembly, so that the material above the gas distribution assembly is in a fluidized state.

[0147] S13, then, the material to be cooled is continuously fed into the heavy cooler body 1 from the feed inlet 101 at the top of the heavy cooler body 1.

[0148] Alternatively, in step S1, the method for completely burying the heat exchanger assembly 3 in the heavy cooler body 1 by using the material is as follows:

[0149] S11, a plurality of gas distribution assemblies are arranged in the heavy cooler body 1 from top to bottom in sequence;

[0150] The material to be cooled is continuously fed into the heavy cooler body 1 from the feed inlet 101 at the top of the heavy cooler body 1.

[0151] S12, when the material level height rises to the lowest layer of the gas distribution assembly, the lowest layer of the gas distribution assembly is started to introduce dry cooling gas, so that the material above the gas distribution assembly enters a fluidized state.

[0152] S13, when the material level height rises to the upper gas distribution assembly, the lower gas distribution assembly is closed or turned off, the upper gas distribution assembly is turned on to continue to pass in dry cold gas, and the heat exchanger assembly 3 between the lower gas distribution assembly and the upper gas distribution assembly is passed in refrigerant to cool the material.

[0153] The above operation is sequentially performed upwards until the material level reaches the preset height, and finally the material fluidization section 100 and the gravity cooling section 200 arranged upwards and downwards are formed.

[0154] The utility model has the following beneficial effects when processing powder and particle products, especially when processing products prone to moisture absorption and caking produced by fermentation plants:

[0155] 1. The problem of material caking and scarring on the surface of the heat exchange plate (or tube) is effectively solved, especially the first and second heat exchange groups in contact with the feed, thereby ensuring long-term stable operation of the equipment without blockage, scarring, and unchanged heat exchange efficiency, and the material itself is free of lumps during the cooling process.

[0156] 2. The cooling process is uniform and consistent, the cooling efficiency is further improved, and products with lower temperature, more uniform temperature and moisture, and no moisture absorption can be obtained, thereby effectively solving the product hardening phenomenon during the storage and transportation period.

[0157] 3. The functions of deep drying, moisture uniformization and deep cooling of the material are completed in the same equipment, and the performance of the equipment is widened.

[0158] 4. The height-diameter ratio (height-length ratio or height-width ratio for rectangular equipment) of the equipment is reduced, and uniform and consistent deep cooling effect can still be ensured under a lower height-diameter ratio, or a larger cross section can be used under the same height and the cooling effect is uniform and consistent, thereby improving the production capacity of the equipment. The reduction of equipment height also reduces the investment in equipment and plant.

[0159] Example 2

[0160] As shown in Figure 2 The difference from example 1 is that the material fluidization section 100 is provided with a heat exchanger assembly 3 connected with a heat exchange medium supply system for providing refrigerant for the heat exchanger assembly 3 in the material fluidization section 100. Specifically, three layers of heat exchanger assemblies are provided in this embodiment, the material fluidization section 100 is provided with one layer of heat exchanger assembly 3, and one layer of fluidization wind gas distribution assembly 2 is arranged below the heat exchanger assembly 3 in the material fluidization section 100. The gravity cooling section 200 is provided with two layers of heat exchanger assemblies 3 from top to bottom, and the corresponding displacement wind gas distribution assembly 4 is provided with two layers; the fluidization wind gas distribution assembly 2 and the displacement wind gas distribution assembly 4 are connected with the gas supply system.

[0161] The discharge speed of the material is controlled by the discharger 7, and the upper surface 9 of the material layer is higher than the uppermost heat exchanger assembly 3 by a certain height, so as to ensure that the heat exchanger assembly 3 is completely buried in the material.

[0162] In the embodiment, dry gas is introduced into the fluidization air gas distribution assembly 2, and the flow rate of the introduced gas is such that the material at the upper part thereof is in a fluidized state. While eliminating the feeding cone and segregation phenomenon and replacing the humid gas of the feed, the material is deeply dried and efficiently cooled by using the high heat transfer and mass transfer rate in the fluidized state, so as to further reduce the moisture of the feed, and eliminate the difference between the feed temperature and the moisture.

[0163] The upper surface 9 of the fluidized material layer is located above the heat exchanger assembly (for example, 0-200 mm), so as to ensure that the heat exchanger is in a full filling state with the material for heat exchange, and to reduce the energy consumption required for overcoming the resistance of the material layer.

[0164] In the embodiment, the implementation effect of an industrial device for cooling 70% lysine fluidized bed granulation products in a certain fermentation plant is given. The bulk density of the material is 580 kg / m 3 , the particle size of the material ranges from 0.6 mm to 1.7 mm, and the average particle size is 1.1 mm. The critical fluidization speed calculated according to the average particle size of the particles is 0.21 m / s (which varies with air temperature and pressure parameters). The cooling parameters and effects are as follows:

[0165] 1. The fluidization air or replacement air provided by the gas distribution assembly is dry cold air after the ambient air is dehumidified and cooled, the air temperature is 20℃-25℃, and the dew point temperature is ≤0℃. By controlling the dew point temperature of the introduced gas, the dew point temperature of the material side gas environment in the heavy cooler body 1 is reduced, the use of lower temperature refrigerant is realized, the wall of the heat exchanger assembly 3 is not scabbed, and the cooling efficiency is effectively improved.

[0166] 2. Three layers of cooling sections are arranged from top to bottom, which are high-temperature cooling section, medium-temperature cooling section and low-temperature cooling section. The high-temperature cooling section is cooled by combined cooling of cooling water and fluidization wind (a small amount of displacement wind is added when the displacement wind is opened). The cooling water inlet temperature of the heat exchanger assembly 3 is controlled at 30-35℃, which reduces the heat transfer temperature difference between the material and the coolant, and also avoids excessive air relative humidity to cause material scabbing on the wall of the heat exchanger assembly 3 or moisture absorption or condensation on the surface of the particles to form hardening. When the displacement wind gas assembly is completely closed, the fluidization wind speed is 0.3-0.6m / s, and the fluidization number is between 1.4-2.9. When the displacement wind gas assembly is opened, the total air volume of the fluidization wind and the displacement wind remains unchanged, i.e. the fluidization number generated by the total air volume is still between 1.4-2.9. At this time, the fluidization wind speed calculated according to the ventilation volume of the fluidization wind gas assembly is reduced to 0.2m / s, and the corresponding fluidization number is 0.95, so as to ensure that the material is uniformly and fully in the bubbling fluidization state under the operation of the two working conditions, and the water vapor contained in the air in the material gap is brought out to avoid the local material flow blockage. When the fluidization number is between 1.4-2.9, the heat transfer efficiency between the fluidized material and the heat transfer wall is also high, and the scouring of the material in the fluidization to the heat transfer wall also prevents or reduces the wall scabbing.

[0167] The cooling water inlet temperature of the heat exchanger assembly 3 in the medium-temperature cooling section is controlled at 22-25℃, which obtains a relatively ideal cooling effect while avoiding scabbing. At the same time, the displacement wind is introduced, and the operating wind speed is 0.05-0.1m / s, so that the material is in the fluidization number of 0.24-0.48, the water vapor in the material gap is brought out to maintain a dry air environment, and the material is in an aerated state to improve the material flowability. Because the flowability of 70% lysine particles is good, and the moisture in the material has been fully replaced in the high-temperature cooling section, the displacement wind can also not be introduced in dry seasons to save air volume.

[0168] The cooling water inlet temperature of the heat exchanger assembly 3 in the low-temperature cooling section is controlled at 8-20℃, which can obtain a deep cooling effect of 25-30℃ or below. At this time, the material has been cooled to near the discharge temperature, the heat transfer temperature difference between the material and the coolant is low, the material is in a fully dry and cold environment, and there is basically no material moisture or condensation. Generally, the displacement wind is not needed to be introduced. The displacement wind can also be opened according to the material and weather conditions, etc. If the displacement wind is introduced, the operating wind speed is similar to or lower than that in the medium-temperature cooling section, but the operating wind speed generated by the sum of the ventilation volumes of the two displacement wind gas assemblies should not exceed the fluidization number of 0.5.

[0169] The effects are as follows:

[0170] (1) In the actual application, the gravity flow indirect cooler of the embodiment can continuously run for more than 60 days without material caking and scabbing on the heat exchanger in the hot and humid weather period in summer; the cooling effect is stable and continuous, and when the feed temperature is 75-80°C, the material can be cooled to about 25°C; the temperature difference of the cooled material is very small.

[0171] The above cooling effect, combined with strict control measures for moisture in the upstream drying process and the downstream conveying and packaging process, basically eliminates the hardening phenomenon of 70% lysine granular packaging products during long-term storage.

[0172] (2) Product quality improvement. The slow and controllable flow of material particles effectively prevents product abrasion and fragmentation, and no fine powder is generated during the cooling process. The indirect heat transfer method basically avoids the contact between the material and the air, thereby avoiding the increase of the product moisture content during the cooling process; the deeply dehumidified dry air can even make the moisture distribution of the material more uniform and further reduce the moisture content.

[0173] (3) During the cooling process, only less than 1500m 3 / h of exhaust gas is discharged, which is more than 90% lower than the 15000m 3 / h of exhaust gas discharged by the fluidized bed cooling process, and nearly zero emission is achieved; the exhaust gas is combined with a large amount of dry exhaust gas for dust and odor removal treatment, without the need for separate.

[0174] (4) High energy utilization efficiency. Since indirect cooling water heat exchange is used, the dehumidification and cooling steps of air cooling are saved, and the ice water consumption in summer is reduced from 120m 3 / h to 25m 3 / h, saving about 80%.

[0175] Using the gravity flow of the material itself, a large number of pressurized and negative pressure suction steps of fluidized air and equipment operation steps are saved, and the installed power of the whole system is reduced from 125kw to 18kw, saving about 85% of power consumption.

[0176] (5) The fluidized bed and its attached bag dust collector, drum induced fan and other auxiliary equipment occupy an area of more than 200m 2 , while the heavy cooler saves large equipment such as bag dust collector and drum induced fan and has less auxiliary equipment, and occupies an area of only 60m 2 , saving 70%, thus saving equipment and plant investment.

[0177] Example 3

[0178] For example, Figure 3The difference between the embodiment 1 and the embodiment 2 is that the material fluidization section 100 is provided with a layer of heat exchanger assembly 3, and the upper and lower sides of the heat exchanger assembly 3 in the material fluidization section 100 are respectively provided with a layer of fluidization air distribution assembly 2.

[0179] In the embodiment, two groups of fluidization air distribution assemblies 2 can be used to simultaneously perform deep drying and cooling operations on the incoming material, further improving the quality of the product. The following is an explanation:

[0180] By introducing dry gas into the upper fluidization air distribution assembly 2, the flow rate of the introduced gas, or by adding the air flow rate from the lower fluidization air distribution assembly, the upper limit of the fluidization number of the fluidized material layer can be operated between 3 and 6, and the material layer is in a more intense boiling state. While completely eliminating the feed cone and segregation phenomenon, and fully replacing the moisture gas in the feed, the high heat and mass transfer rate of the fluidized material layer is used to perform deep drying on the material to further reduce the moisture content of the feed, and to eliminate the differences in moisture content of the material at different locations. In order to further improve the effect of deep drying and eliminate the moisture difference of particles of different particle sizes, the temperature of the dry gas can be appropriately increased until it approaches the feed temperature, in order to reduce the relative humidity of the gas in the gap between the particles and increase the mass transfer and heat transfer driving force for the diffusion of moisture in the material to the gas.

[0181] For materials with strong moisture absorption and caking characteristics, the material temperature is still relatively high when the material passes through the upper fluidization air distribution assembly, and the flow rate of the gas introduced by the lower fluidization air distribution assembly 2 (including the air flow rate when the displacement air distribution assembly is working) keeps the fluidization number above 1, so that the material layer in the area where the heat exchanger assembly 3 is located is also uniformly and fully operated in a bubbling fluidization state, avoiding the situation of local material flow blockage; the heat transfer efficiency of the cooling process of the material in the fluidization state with the heat exchange wall surface is also high, and the scouring of the material in the fluidization state with the heat exchange wall surface also prevents or reduces the scarring of the material at the high temperature section on the wall surface.

[0182] When processing materials with low hygroscopic and agglomerating properties, or during production in dry and cold seasons, a small amount of dry, cold gas is introduced into the lower fluidizing air distribution component 2 in conjunction with the upper fluidizing air distribution component 2. This displaces the hot gas in the voids between material particles that have moved down to the heat exchanger area (heat exchanger component 3) and discharges it upwards into the fluidized bed. Since the moisture in the material has already been further removed and homogenized in the material layer above the upper fluidizing air distribution component 2, the gas in the particle voids still maintains a very low moisture content. Therefore, the possibility of material agglomeration or scaling can be avoided by introducing a small amount of dry, cold gas. Alternatively, the lower fluidizing air distribution component 2 can be de-ventilated, and only the heat exchanger component 3 is used to cool the material. In both cases, the lower fluidizing air distribution component is equivalent to the displacement air distribution component in Example 1, and the selection of its operating air velocity is similar, thereby saving the power consumption required for gas pressurization.

[0183] Example 4

[0184] The difference from Embodiment 1 is that each heat exchanger assembly 3 includes multiple heat exchangers arranged in series, with adjacent heat exchangers spaced apart from each other, and a gas distribution assembly connected to the gas supply system is provided between two adjacent heat exchangers.

[0185] Specifically, such as Figure 11 As shown, each heat exchanger assembly 3 includes two sets of heat exchangers arranged in series, one above the other. Adjacent heat exchangers are spaced apart, and the inlet and outlet distribution manifolds of adjacent heat exchangers are connected sequentially. Refrigerant enters multiple sets of heat exchangers in series to increase the total temperature difference between the refrigerant inlet and outlet, thereby reducing the refrigerant flow rate. When each heat exchanger assembly includes multiple layers of heat exchangers, in addition to setting a gas distribution assembly in the bottom heat exchanger, gas distribution assemblies can also be set between the internal heat exchangers of each heat exchanger assembly as needed. This reduces the height of the fluidizing air or displacement air passing through the material layer, thus reducing the non-uniformity of gas distribution and the resistance of gas passing through the material layer.

Claims

1. A gravity flow indirect cooler characterized by: The heavy cooler body (1), a gas distribution assembly, a heat exchanger assembly (3), a gas supply system and a heat exchange medium supply system are included. The heat exchanger assembly (3) is a plate heat exchanger or a tube heat exchanger, and a first material passage (1000) is arranged between the heat exchange plates or the heat exchange tubes of the heat exchanger assembly (3). The gas distribution assembly is horizontally arranged in the heavy cooler body (1) and includes air distribution units (2000) arranged at intervals along the cross section of the heavy cooler body (1) and second material passages (3000) arranged between the air distribution units (2000). The heavy cooler body (1) is a vertical housing, and the top of the heavy cooler body (1) is provided with a feeding port (101) and an exhaust port (102), and the bottom of the heavy cooler body (1) is provided with a discharging port (103). The heavy cooler body (1) is provided with a material fluidization section (100) and a gravity cooling section (200) from top to bottom. The gravity cooling section (200) is provided with a heat exchanger assembly (3) connected with the heat exchange medium supply system, and the heat exchange medium supply system is used to provide refrigerant to the heat exchanger assembly (3) of the gravity cooling section (200). The gas distribution assembly includes a fluidization air gas distribution assembly (2) arranged in the material fluidization section (100). The fluidization air gas distribution assembly (2) is connected with the gas supply system and is used to introduce dry gas into the heavy cooler body (1) to make the material in the material fluidization section (100) present a fluidized state.

2. The gravity flow indirect cooler of claim 1, wherein: The gravity cooling section (200) is provided with multiple layers of heat exchanger assemblies (3) from top to bottom, each layer of heat exchanger assembly (3) forms a cooling section, and the temperature of the refrigerant of each layer of heat exchanger assembly (3) decreases from top to bottom.

3. The gravity flow indirect cooler of claim 1 or 2, wherein: Each layer of heat exchanger assembly (3) uses an independent heat exchange medium supply system, and the heat exchange medium supply system can independently control the flow and / or temperature of the refrigerant in the connected heat exchanger assembly (3).

4. The gravity flow indirect cooler of claim 3, wherein: The gas distribution assembly further includes a displacement air gas distribution assembly (4) arranged in the gravity cooling section (200). The displacement air gas distribution assembly (4) is connected with the gas supply system and is used to introduce dry gas into the heavy cooler body (1). Each layer of heat exchanger assembly (3) is provided with a layer of displacement air gas distribution assembly (4) below.

5. The gravity flow indirect cooler of claim 1, wherein: The material fluidization section (100) is provided with a heat exchanger assembly (3) connected with the heat exchange medium supply system. The heat exchange medium supply system is used to provide refrigerant for the heat exchanger assembly (3) in the material fluidization section (100).

6. The gravity flow indirect cooler of claim 5, wherein: Each layer of heat exchanger assembly (3) includes multiple layers of heat exchangers arranged in series from top to bottom, and a gas distribution assembly connected with the gas supply system is arranged between two adjacent heat exchangers.

7. The gravity flow indirect cooler of claim 1, wherein: An auxiliary bin (5) is further included, the inlet of the auxiliary bin (5) is connected with the discharging port (103), and the outlet of the auxiliary bin (5) is connected with the feeding port (101).

8. The gravity flow indirect cooler of claim 1, wherein: A material level meter (6) and an adjustable flow discharger (7) are further included. The material level meter (6) is arranged at the top of the heavy cooler body (1) and is used to measure the material level height in the heavy cooler body (1). The discharger (7) is connected with the discharge port (103) and is used for adjusting the discharging speed of the material to control the material level in the recolder body (1).

9. The gravity flow indirect cooler of claim 1 or 5, wherein: The gas supply system comprises a gas dehumidification device and / or a cooling device, and the heat exchange medium supply system comprises a fluid cooling device; The gas dehumidification device is used for removing the moisture in the gas to obtain dry gas, the gas cooling device is used for controlling the temperature of the dry gas, and the fluid cooling device is used for controlling the temperature of the refrigerant to avoid moisture absorption, caking or scabbing on the wall of the heat exchanger.

10. The gravity flow indirect cooler of claim 1, wherein: The air distribution unit (2000) comprises a gas distribution pipe (8), and the air distribution pipe (8) is provided below with air distribution holes (81). The air distribution holes (81) are arranged in rows along the axial direction of the gas distribution pipe (8) and are spaced apart from each other, and at least one row of air distribution holes (81) is arranged below each gas distribution pipe (8).

11. The gravity flow indirect cooler of claim 10, wherein: The gas distribution pipe (8) is a straight pipe.

12. The gravity flow indirect cooler of claim 10, wherein: The extending direction of the gas distribution pipe (8) is perpendicular to the extending direction of the heat exchange pipe or the heat exchange plate in the heat exchanger assembly (3) in the horizontal direction.

13. The gravity flow indirect cooler of claim 10, wherein: The opening ratio of the fluidization air gas distribution assembly (2) is greater than that of the replacement air gas distribution assembly (4).

14. The gravity flow indirect cooler of claim 10, wherein: The opening ratio of the air distribution hole (81) of the uppermost fluidization air gas distribution assembly (2) below the feed port (101) is greater than that at other positions.

15. The gravity flow indirect cooler of claim 1, wherein: The heat exchanger assembly (3) comprises a plurality of heat exchange pipes arranged in the horizontal direction and spaced apart, and the heat exchange pipes are serpentine pipes extending upward and downward.

16. The gravity flow indirect cooler of claim 15, wherein: Two adjacent serpentine heat exchange pipes are arranged in staggered rows upward and downward.

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