CN220413149U

CN220413149U - Sludge low-temperature desiccator

Info

Publication number: CN220413149U
Application number: CN202321785298.2U
Authority: CN
Inventors: 吴俊平
Original assignee: Foshan Yongbang Environmental Protection Technology Co ltd
Current assignee: Foshan Yongbang Environmental Protection Technology Co ltd
Priority date: 2023-07-07
Filing date: 2023-07-07
Publication date: 2024-01-30
Anticipated expiration: 2033-07-07

Abstract

The utility model relates to a sludge low-temperature desiccator, which has the technical scheme that: comprising the following steps: a drying bin and a control mechanism; the control mechanism is positioned at one side outside the drying bin; the drying cabin is internally divided into a drying chamber and a heat pump chamber by a plurality of partition boards; the top of the drying chamber is communicated with the top of the heat pump chamber, and a first conveying mechanism and a second conveying mechanism are sequentially arranged in the drying chamber from top to bottom: at least one heat pump mechanism and at least one first fan assembly corresponding to the heat pump mechanism are arranged in the heat pump chamber; the first fan assembly is positioned at the bottom of the drying chamber; through the design of internal and external environment isolation, the sludge is dried in a low-oxygen micro-oxygen environment, so that the energy consumption is low, the environment is protected, the efficiency is high, and the drying effect is good.

Description

Sludge low-temperature desiccator

Technical Field

The utility model relates to the technical field of sludge drying equipment, in particular to a sludge low-temperature dryer.

Background

With the development of urban construction and the improvement of living standard, the generation amount of urban domestic sludge is larger and larger, and the accumulation of the urban domestic sludge in a long time very affects urban environment and air quality; the current method for carrying out batch treatment on municipal domestic sludge is generally a physical method and a biochemical method, wherein the physical method is generally drying treatment, namely, most of water contained in the sludge is removed, and then the rest slag is subjected to innocent treatment or is converted into other use; compared with the biochemical treatment mode, the physical drying treatment mode has obvious advantages, such as small occupied area of treatment equipment, short treatment period, difficult secondary pollution and the like.

The existing physical drying treatment mode generally utilizes heat energy to remove most of water content from the sludge, and moisture in the sludge generally refers to moisture or other volatile liquid components to be vaporized and escaped through heating, so that drying of the sludge is realized; for example, patent number CN202210509779.4 discloses a belt type sludge drier using electric heat drying, which uses electric heat drier to generate heat, uses blower to blow the heat generated by electric heat drier to the position of sludge to be dried, and heats the sludge to evaporate water and other volatile liquid components in the sludge, thus realizing drying operation of the sludge; however, a large amount of electric power energy is consumed in the drying process, so that the energy consumption is high, and the drying treatment efficiency is low; and the vaporized volatile matters are easy to cause environmental pollution in the drying process.

Disclosure of Invention

Aiming at the defects existing in the prior art, the utility model aims to provide a sludge low-temperature desiccator so as to solve the technical problems existing in the technical background.

The technical aim of the utility model is realized by the following technical scheme: a sludge low temperature dryer comprising: a drying bin and a control mechanism; the control mechanism is positioned at one side outside the drying bin; the drying cabin is internally divided into a drying chamber and a heat pump chamber by a plurality of partition boards; the top of the drying chamber is communicated with the top of the heat pump chamber, and a first conveying mechanism and a second conveying mechanism are sequentially arranged in the drying chamber from top to bottom: at least one heat pump mechanism and at least one first fan assembly corresponding to the heat pump mechanism are arranged in the heat pump chamber; the first fan assembly is positioned at the bottom of the drying chamber; the air inlet end of the first fan assembly penetrates through the partition plate and then is communicated with the heat pump chamber; the air outlet end of the first fan assembly is communicated with the drying chamber and is positioned below the second conveying mechanism; a second fan assembly is arranged in the drying chamber; the air inlet end of the second fan assembly penetrates through the partition plate and then is communicated with the heat pump chamber; the first conveying mechanism, the second conveying mechanism, the heat pump mechanism, the first fan assembly and the second fan assembly are respectively and electrically connected with the control mechanism; a feeding hole is formed in one end of the top of the drying bin; a first hopper, a second hopper and a third hopper are arranged in the drying chamber; the first hopper and the feeding hole are provided with a discharge hole facing the feeding end of the first conveying mechanism; the second hopper is positioned below the discharge end of the first conveying mechanism, and the outlet of the second hopper faces the feed end of the second conveying mechanism; the third hopper is positioned below the discharge end of the second conveying mechanism; the drying bin is provided with a discharge hole; the discharge hole of the third hopper is communicated with the discharge hole; a plurality of fresh air inlets are formed in the top of the drying bin; and the upper cover of the fresh air port is provided with a sealing cover.

Optionally, the heat pump mechanism includes: 2 heat pump units; 2 heat pump units are oppositely arranged in the heat pump chambers; the air inlet of the first fan assembly faces 2 heat pump units; the heat pump unit includes: the device comprises a first compressor, a second compressor, a first liquid storage tank, a second liquid storage tank, an evaporator, a first condenser, a second condenser, a first expansion valve, a second expansion valve, a first filter, a second filter, a heat regenerator and an electric heater; the first compressor and the second compressor are fixedly arranged at the bottom of the heat pump chamber in a longitudinal arrangement manner; the first liquid storage tank and the second liquid storage tank are longitudinally arranged and are positioned at one side of the first compressor and one side of the second compressor; the evaporator is arranged at the other side of the first compressor and the second compressor; the heat regenerator is arranged above the first compressor and the second compressor; the second condenser is fixedly arranged on one side of the heat regenerator; the electric heater is arranged on one side, far away from the heat regenerator, of the second condenser; an air duct corresponding to the second fan assembly is arranged in the heat pump chamber; an air outlet of the air duct is communicated with the second fan assembly and is positioned above the heat regenerator; the first condenser is fixedly arranged at an air inlet of the air duct; one end of the evaporator, the first compressor, the first liquid storage tank, the first condenser, the first expansion valve and the first filter are communicated through copper pipes; the other end of the evaporator, the second compressor, the second liquid storage tank, the second condenser, the second expansion valve and the second filter are communicated through copper pipes.

Optionally, the first fan assembly includes: 2 first fans; the 2 first fans are fixedly arranged at the bottom of the drying chamber; the air inlets of the 2 first fans face to the 2 heat pump units in a one-to-one correspondence mode.

Optionally, the first conveying mechanism includes: the first transmission net belt, a plurality of first transmission shafts and a first motor; the first transmission shafts are rotatably arranged in the drying chamber; the first conveying mesh belt is wound on a plurality of first transmission shafts; the first motor is fixedly arranged on the outer wall of the drying bin; the output end of the first motor passes through the drying bin and is fixedly connected with the input end of any one of the first transmission shafts.

Optionally, the second conveying mechanism includes: the second transmission net belt, a plurality of second transmission shafts and a second motor; the second transmission shafts are rotatably arranged in the drying chamber and are positioned above the second conveying mesh belt; the second conveying mesh belt is wound on a plurality of second transmission shafts; the second motor is fixedly arranged on the outer wall of the drying bin; the output end of the second motor passes through the drying bin and is fixedly connected with the input end of any second transmission shaft.

Optionally, the second fan assembly includes: a plurality of second fans; the second fans are fixedly arranged in the drying chamber, and air inlets of the second fans penetrate through the partition plates and then are communicated with the air channels.

Optionally, the control mechanism includes: the device comprises an electric cabinet, at least one electric box, a controller and a control screen; the control screen is arranged at the upper end of one side of the electric cabinet; the electric box and the controller are arranged in the electric cabinet; the control screen is respectively and electrically connected with the electric box and the controller.

In summary, the utility model has the following beneficial effects: the whole adopts the design of isolating the internal environment and the external environment, and the sludge is dried in a low-oxygen micro-oxygen environment, so that the emission of harmful gases is reduced, and simultaneously, harmful substances generated by oxidative decomposition of the sludge in high-temperature drying are avoided; through the design of internal and external environment isolation, the sludge is subjected to drying treatment in a low-oxygen micro-oxygen environment, so that the emission of harmful gases is reduced, and meanwhile, harmful substances generated by oxidative decomposition of the sludge in high-temperature drying are avoided; the circulating air system is utilized to enable the surface of the sludge to be fully contacted with the heated air, so that the drying speed is faster and the effect is better.

Drawings

FIG. 1 is an assembly view of the present utility model;

FIG. 2 is a schematic diagram of the structural relationship of the components of the present utility model;

FIG. 3 is a left side view of FIG. 2;

fig. 4 is a right side view of fig. 3.

In the figure: 1. a drying bin; 2. a control mechanism; 2001. an electric cabinet; 2002. a control screen; 3. a drying chamber; 4. a thermal pump chamber; 5. a heat pump mechanism; 51. a heat pump unit; 5101. a first compressor; 5102. a first liquid storage tank; 5103. an evaporator; 5104. a first condenser; 5105. a first expansion valve; 5106. a first filter; 5107. a regenerator; 5108. an electric heater; 5109. a second condenser; 6. a first fan assembly; 6001. a first fan; 7. a second fan assembly; 7001. a second fan; 8. a first conveying mechanism; 8001. a first conveyor belt; 9. a second conveying mechanism; 9001. a second conveyor belt; 9002. a second motor; 10. a first hopper; 11. a third hopper; 12. a feed hole; 13. a discharge hole; 14. a sealing cover; 15. and an air duct.

Detailed Description

In order that the objects, features and advantages of the utility model will be readily understood, a more particular description of the utility model will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Several embodiments of the utility model are presented in the figures. This utility model may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances. The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

In the present utility model, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature. The terms "vertical," "horizontal," "left," "right," "up," "down," and the like are used for descriptive purposes only and are not to indicate or imply that the devices or elements being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the utility model.

The present utility model will be described in detail below with reference to the accompanying drawings and examples.

The utility model provides a sludge low-temperature desiccator, as shown in figures 1-4, comprising: a drying bin 1 and a control mechanism 2; the control mechanism 2 is positioned at one side outside the drying bin 1; the drying bin 1 is internally divided into a drying chamber 3 and a heat pump chamber 4 by a plurality of partition boards; the top of the drying chamber 3 is communicated with the top of the heat pump chamber 4, and a first conveying mechanism 8 and a second conveying mechanism 9 are sequentially arranged in the drying chamber 3 from top to bottom: at least one heat pump mechanism 5 and at least one first fan assembly 6 corresponding to the heat pump mechanism 5 are arranged in the heat pump chamber 4; the first fan 6001 is located at the bottom of the drying chamber 3; the air inlet end of the first fan assembly 6 passes through the partition plate and then is communicated with the heat pump chamber 4; the air outlet end of the first fan assembly 6 is communicated with the drying chamber 3 and is positioned below the second conveying mechanism 9; a second fan assembly 7 is arranged in the drying chamber 3; the air inlet end of the second fan assembly 7 passes through the partition plate and then is communicated with the heat pump chamber 4; the first conveying mechanism 8, the second conveying mechanism 9, the heat pump mechanism 5, the first fan assembly 6 and the second fan assembly 7 are respectively and electrically connected with the control mechanism 2; a feeding hole 12 is formed in one end of the top of the drying bin 1; a first hopper 10, a second hopper and a third hopper 11 are arranged in the drying chamber 3; the first hopper 10 and the feeding hole 12 have a discharging hole facing the feeding end of the first conveying mechanism 8; the second hopper is positioned below the discharge end of the first conveying mechanism 8, and the outlet of the second hopper faces the feed end of the second conveying mechanism 9; the third hopper 11 is positioned below the discharge end of the second conveying mechanism 9; a discharge hole 13 is formed in the drying bin 1; the discharge hole 13 is communicated with the discharge hole of the third hopper 11; a plurality of fresh air inlets are formed in the top of the drying bin 1; the fresh air port upper cover is provided with a sealing cover 14.

In the embodiment, as shown in fig. 1-4, a drying bin 1 is formed by splicing three bins which are arranged in parallel and are communicated in sequence, and 1 heat pump mechanism 5, a first fan assembly 6 and a second fan assembly 7 are arranged in any drying bin 1; the drying bin 1 is divided into a drying chamber 3 and a heat pump chamber 4 by a plurality of partition boards, and the heat pump chamber 4 and the drying chamber 3 are arranged side by side; the first conveying mechanism 8 and the second conveying mechanism 9 span three chambers; the first conveying mechanism 8 and the second conveying mechanism 9 are arranged in the drying chamber 3 from top to bottom, and the conveying directions of the first conveying mechanism 8 and the second conveying mechanism 9 are opposite, so that sludge with drying can be conveyed in the drying chamber 3 in a rotary mode, and the drying effect of the sludge is improved.

Further, the heat pump mechanism 5 includes: 2 heat pump units 51;2 heat pump units 51 are disposed in the heat pump chamber 4 in opposition; the air inlet of the first fan assembly 6 faces 2 heat pump units 51; the heat pump unit 51 includes: a first compressor 5101, a second compressor, a first liquid storage tank 5102, a second liquid storage tank, an evaporator 5103, a first condenser 5104, a second condenser 5109, a first expansion valve 5105, a second expansion valve, a first filter 5106, a second filter, a regenerator 5107, and an electric heater 5108; the first compressor 5101 and the second compressor are fixedly arranged at the bottom of the heat pump chamber 4 in a longitudinal arrangement; the first liquid storage tank 5102 and the second liquid storage tank are longitudinally arranged and are positioned at one side of the first compressor 5101 and one side of the second compressor; the evaporator 5103 is provided at the other side of the first compressor 5101 and the second compressor; the regenerator 5107 is disposed above the first compressor 5101 and the second compressor; the second condenser 5109 is fixedly arranged at one side of the regenerator 5107; the electric heater 5108 is disposed on a side of the second condenser 5109 remote from the regenerator 5107; an air duct 15 corresponding to the second fan assembly 7 is arranged in the heat pump chamber 4; the air outlet of the air duct 15 is communicated with the second fan assembly 7 and is positioned above the heat regenerator 5107; the first condenser 5104 is fixedly arranged at the air inlet of the air duct 15; one end of the evaporator 5103, the first compressor 5101, the first liquid storage tank 5102, the first condenser 5104, the first expansion valve 5105 and the first filter 5106 are communicated through copper pipes; the other end of the evaporator 5103, the second compressor, the second liquid storage tank, the second condenser 5109, the second expansion valve and the second filter are communicated through copper pipes.

In the present embodiment, the heat pump mechanism 5 is constituted by two 2 heat pump units 51 arranged in parallel, and the heat pump units 51 mainly include: the device comprises a first compressor 5101, a second compressor, a first liquid storage tank 5102, a second liquid storage tank, an evaporator 5103, a first condenser 5104, a second condenser 5109, a first expansion valve 5105, a second expansion valve, a first filter 5106, a second filter, a regenerator 5107 and an electric heater 5108; one end of the evaporator 5103, the first compressor 5101, the first liquid storage tank 5102, the first condenser 5104, the first expansion valve 5105 and the first filter 5106 are connected through copper pipes to form first circulation refrigeration; the other end of the evaporator 5103, the second compressor, the second liquid storage tank, the second condenser 5109, the second expansion valve and the second filter are connected through copper pipes to form a second refrigeration cycle; 2 circulation refrigeration working principle: the compressor compresses refrigerant vapor having a low pressure into vapor having a high pressure, and the vapor is sent to the condenser after the pressure is increased, condensed into liquid having a high pressure in the condenser (heat release, heating process), throttled by the expansion valve, sent to the evaporator 5103 after becoming liquid having a low pressure, evaporated in the evaporator 5103 to become vapor having a low pressure (heat absorption, cooling process), and sent to the inlet of the compressor, thereby completing the refrigeration cycle.

Further, the first fan assembly 6 includes: 2 first fans 6001; the 2 first fans 6001 are fixedly arranged at the bottom of the drying chamber 3; the air inlets of the 2 first fans 6001 face the 2 heat pump units 51 in a one-to-one correspondence manner.

In the present embodiment, the first fan assembly 6 is constituted by 2 first fans 6001 corresponding to the 2 heat pump units 51, respectively, the first fans 6001 being blowers; the tuyere of the first fan 6001 faces the second condenser 5109 so as to blow out the heat generated in the second condenser 5109, and the sludge on the first conveyor mechanism 8 and the second conveyor mechanism 9 is subjected to low-temperature heating and drying operation.

Further, the first conveying mechanism 8 includes: the first conveying net belt 8001, a plurality of first transmission shafts and a first motor; the first transmission shafts are rotatably arranged in the drying chamber 3; the first conveying mesh belt 8001 is wound around a plurality of first transmission shafts; the first motor is fixedly arranged on the outer wall of the drying bin 1; the output end of the first motor passes through the drying bin 1 and is fixedly connected with the input end of any first transmission shaft; in application, the first motor is a servo motor; the first transfer belt 8001 is composed of a stainless steel mesh and a polyester mesh laid on the surface of the stainless steel mesh.

Further, the second conveying mechanism 9 includes: a second conveyor belt 9001, a plurality of second transmission shafts and a second motor 9002; the second transmission shafts are rotatably arranged in the drying chamber 3 and are positioned above the second conveying mesh belt 9001; the second conveying mesh belt 9001 is wound on a plurality of second transmission shafts; the second motor 9002 is fixedly arranged on the outer wall of the drying bin 1; the output end of the second motor 9002 passes through the drying bin 1 and is fixedly connected with the input end of any second transmission shaft; in application, the second motor 9002 is also a servo motor; the second conveyor belt 9001 is composed of a stainless steel mesh and a polyester mesh laid on the surface of the stainless steel mesh, like the first conveyor belt 8001, and has a mesh slightly larger than that of the second conveyor belt 9001 because the sludge on the conveyor belt can change in quality and shape during drying.

Further, the second fan assembly 7 includes: a plurality of second fans 7001; the second fans 7001 are all fixedly arranged in the drying chamber 3, and air inlets of the second fans penetrate through the partition plates and then are communicated with the air duct 15.

In this embodiment, the second fan assembly 7 is composed of a plurality of second fans 7001 disposed in parallel in the drying chamber 3, the second fans 7001 are mainly exhaust fans, the second fans 7001 are disposed in gaps between the first conveying mesh belt 8001 and the second conveying mesh belt 9001, and are mainly used for feeding high-humidity medium-temperature gas into the hot pump chamber 4 through the top of the drying chamber 3, and after being heated by the first condenser 5104, the gas is blown into the drying chamber 3 under the action of the second fans 7001, so as to perform compensation heating on sludge on the first conveying mechanism 8 in the drying chamber 3, thereby further improving drying efficiency.

Further, the control mechanism 2 includes: an electric cabinet 2001, at least one electric box, a controller, and a control screen 2002; the control screen 2002 is arranged at the upper end of one side of the electric cabinet 2001; the electric box and the controller are arranged in the electric cabinet 2001; the control screen 2002 is electrically connected to the electronic box and the controller, respectively.

In this embodiment, the controller may be a single-chip microcomputer, an MCU, a PLC, or the like, and may control various electrical components, and in this embodiment, the MCU is selected.

As shown in fig. 1-4:

in the specific implementation process, the equipment condition is checked, and the equipment can be ensured to normally run; the control mechanism 2 controls the electric heater 5108 in the heat pump mechanism 5 to be electrified and heated, when the air around the heater reaches a certain temperature (and the heating operation of the heater is cut off when appropriate), the first fan 6001 works, and the air with high temperature and drying near the electric heater is blown into the drying chamber 3 so as to heat and dry the sludge on the first conveying mesh belt 8001 and the second conveying mesh belt 9001 in the drying chamber 3, and after the sludge absorbs heat in the process, the air with high temperature and drying becomes air with high humidity and medium temperature, and enters the heat pump chamber 4 from the top of the drying chamber 3; under the cooperation of the first condenser 5104 and the second fan 7001, part of the high-humidity medium-temperature air entering the heat pump chamber 4 is heated by the first condenser 5104 and then is conveyed into the drying chamber 3 from a gap between the first conveying mechanism 8 and the second conveying mechanism 9, so that the sludge on the first conveying mechanism 8 is subjected to compensation heating, and the drying operation of the sludge on the first conveying mechanism 8 is accelerated; the other part of the high-humidity medium-temperature air is dehumidified in the heat pump chamber 4 through the evaporator 5103, the high-humidity medium-temperature air is changed into dry low-temperature air, the dry low-temperature air reaches the second condenser 5109 through the regenerator 5107 to be heated, the low-temperature air after being heated and warmed is changed into dry high-temperature air, and the dry high-temperature air enters the drying chamber 3 along with the negative pressure of the first fan 6001 to heat and dry the sludge on the first conveying mesh belt 8001 and the second conveying mesh belt 9001; through the design of internal and external environment isolation, the sludge is subjected to drying treatment in a low-oxygen micro-oxygen environment, so that the emission of harmful gases is reduced, and meanwhile, harmful substances generated by oxidative decomposition of the sludge in high-temperature drying are avoided; the whole operation adopts a heat pump heat recovery technology, the closed drying mode has no waste heat emission, the energy consumption is effectively reduced, and the emission of dangerous waste is reduced; in the working process, the sludge is statically spread and has no mechanical static friction with the contact surface; through setting up second fan subassembly 7, utilize the circulated air system, make the abundant contact heating air in mud surface, drying speed is faster, and the effect is better.

According to the sludge low-temperature desiccator, the design of isolating the internal environment from the external environment is adopted integrally, and the sludge is dried in a low-oxygen micro-oxygen environment, so that the emission of harmful gases is reduced, and meanwhile, harmful substances generated by oxidative decomposition of the sludge in high-temperature drying are avoided; through the design of internal and external environment isolation, the sludge is subjected to drying treatment in a low-oxygen micro-oxygen environment, so that the emission of harmful gases is reduced, and meanwhile, harmful substances generated by oxidative decomposition of the sludge in high-temperature drying are avoided; the circulating air system is utilized to enable the surface of the sludge to be fully contacted with the heated air, so that the drying speed is faster and the effect is better.

The above description is only a preferred embodiment of the present utility model, and the protection scope of the present utility model is not limited to the above examples, and all technical solutions belonging to the concept of the present utility model belong to the protection scope of the present utility model. It should be noted that modifications and adaptations to the present utility model may occur to one skilled in the art without departing from the principles of the present utility model and are intended to be within the scope of the present utility model.

Claims

1. A sludge low-temperature desiccator, which is characterized by comprising: a drying bin and a control mechanism; the control mechanism is positioned at one side outside the drying bin; the drying cabin is internally divided into a drying chamber and a heat pump chamber by a plurality of partition boards; the top of the drying chamber is communicated with the top of the heat pump chamber, and a first conveying mechanism and a second conveying mechanism are sequentially arranged in the drying chamber from top to bottom: at least one heat pump mechanism and at least one first fan assembly corresponding to the heat pump mechanism are arranged in the heat pump chamber; the first fan assembly is positioned at the bottom of the drying chamber; the air inlet end of the first fan assembly penetrates through the partition plate and then is communicated with the heat pump chamber; the air outlet end of the first fan assembly is communicated with the drying chamber and is positioned below the second conveying mechanism; a second fan assembly is arranged in the drying chamber; the air inlet end of the second fan assembly penetrates through the partition plate and then is communicated with the heat pump chamber; the first conveying mechanism, the second conveying mechanism, the heat pump mechanism, the first fan assembly and the second fan assembly are respectively and electrically connected with the control mechanism;

a feeding hole is formed in one end of the top of the drying bin; a first hopper, a second hopper and a third hopper are arranged in the drying chamber; the first hopper and the feeding hole are provided with a discharge hole facing the feeding end of the first conveying mechanism; the second hopper is positioned below the discharge end of the first conveying mechanism, and the outlet of the second hopper faces the feed end of the second conveying mechanism; the third hopper is positioned below the discharge end of the second conveying mechanism; the drying bin is provided with a discharge hole; the discharge hole of the third hopper is communicated with the discharge hole; a plurality of fresh air inlets are formed in the top of the drying bin; and the upper cover of the fresh air port is provided with a sealing cover.

2. A sludge cryogenic dryer according to claim 1, characterized in that the heat pump mechanism comprises: 2 heat pump units; 2 heat pump units are oppositely arranged in the heat pump chambers; the air inlet of the first fan assembly faces 2 heat pump units; the heat pump unit includes: the device comprises a first compressor, a second compressor, a first liquid storage tank, a second liquid storage tank, an evaporator, a first condenser, a second condenser, a first expansion valve, a second expansion valve, a first filter, a second filter, a heat regenerator and an electric heater; the first compressor and the second compressor are fixedly arranged at the bottom of the heat pump chamber in a longitudinal arrangement manner; the first liquid storage tank and the second liquid storage tank are longitudinally arranged and are positioned at one side of the first compressor and one side of the second compressor; the evaporator is arranged at the other side of the first compressor and the second compressor; the heat regenerator is arranged above the first compressor and the second compressor; the second condenser is fixedly arranged on one side of the heat regenerator; the electric heater is arranged on one side, far away from the heat regenerator, of the second condenser; an air duct corresponding to the second fan assembly is arranged in the heat pump chamber; an air outlet of the air duct is communicated with the second fan assembly and is positioned above the heat regenerator; the first condenser is fixedly arranged at an air inlet of the air duct; one end of the evaporator, the first compressor, the first liquid storage tank, the first condenser, the first expansion valve and the first filter are communicated through copper pipes; the other end of the evaporator, the second compressor, the second liquid storage tank, the second condenser, the second expansion valve and the second filter are communicated through copper pipes.

3. The sludge cryogenic dryer of claim 2, wherein the first fan assembly comprises: 2 first fans; the 2 first fans are fixedly arranged at the bottom of the drying chamber; the air inlets of the 2 first fans face to the 2 heat pump units in a one-to-one correspondence mode.

4. The sludge cryogenic dryer of claim 1, wherein the first conveying mechanism comprises: the first transmission net belt, a plurality of first transmission shafts and a first motor; the first transmission shafts are rotatably arranged in the drying chamber; the first conveying mesh belt is wound on a plurality of first transmission shafts; the first motor is fixedly arranged on the outer wall of the drying bin; the output end of the first motor passes through the drying bin and is fixedly connected with the input end of any one of the first transmission shafts.

5. The sludge cryogenic dryer of claim 4, wherein the second conveying mechanism comprises: the second transmission net belt, a plurality of second transmission shafts and a second motor; the second transmission shafts are rotatably arranged in the drying chamber and are positioned above the second conveying mesh belt; the second conveying mesh belt is wound on a plurality of second transmission shafts; the second motor is fixedly arranged on the outer wall of the drying bin; the output end of the second motor passes through the drying bin and is fixedly connected with the input end of any second transmission shaft.

6. The sludge cryogenic dryer of claim 2, wherein the second fan assembly comprises: a plurality of second fans; the second fans are fixedly arranged in the drying chamber, and air inlets of the second fans penetrate through the partition plates and then are communicated with the air channels.

7. The sludge cryogenic dryer of claim 1, wherein the control mechanism comprises: the device comprises an electric cabinet, at least one electric box, a controller and a control screen; the control screen is arranged at the upper end of one side of the electric cabinet; the electric box and the controller are arranged in the electric cabinet; the control screen is respectively and electrically connected with the electric box and the controller.