Tail gas purification heat recovery device and sludge drying system comprising same

Abstract

The utility model relates to a tail gas purification heat recovery device which comprises a vertically-arranged barrel, a gas inlet and a liquid outlet are formed in the lower portion of the barrel, a gas outlet used for discharging purified gas is formed in the upper portion of the barrel, and therefore a tail gas channel flowing from bottom to top is formed. Wherein at least two spraying heat recovery units are arranged in the barrel body, each spraying heat recovery unit comprises a heat exchange assembly and a spraying assembly, each heat exchange assembly is composed of a plurality of heat exchange parts, a heat exchange medium is arranged in each heat exchange assembly, each spraying assembly comprises a plurality of nozzles, and the direction of the nozzles is opposite to the flowing direction of the tail gas. And the tail gas is subjected to water washing purification and heat recovery through the spraying heat recovery unit, so that the tail gas can be discharged up to the standard. The utility model further relates to a sludge drying system comprising the tail gas purification and heat recovery device.

Description

TECHNICAL FIELD

[0001] The utility model relates to sludge drying tail gas deep treatment technical field, concretely relates to a tail gas purification heat recovery device and including its sludge drying system. BACKGROUND

[0002] In the current sludge treatment process, low-temperature drying process is generally used to convert liquid sludge with water content of 99% or more into granular or powder sludge with water content of 30%-40%. This not only reduces the volume of sludge, but also lays the foundation for subsequent disposal and resource utilization. However, during the low-temperature drying process, tail gas containing impurities and carrying residual heat is generated. If these tail gases are directly discharged without treatment, not only will they pollute the environment, but also the residual heat resources will be wasted. Currently, the existing technology uses a heat pump system to recover the residual heat in the tail gas and simultaneously purify the tail gas during the recovery process. Although this method achieves preliminary recycling of resources and preliminary purification of tail gas to some extent, impurities are still present in the treated tail gas, and the heat recovery efficiency is not high. That is, the final tail gas still does not fully meet the strict environmental emission standards when it is discharged, and the potential pollution risk still exists. Therefore, how to develop a tail gas purification heat recovery device to achieve deep purification and residual heat recovery of tail gas is an urgent problem to be solved. SUMMARY

[0003] In view of the problems existing in the prior art, the first object of the utility model is to provide a tail gas purification heat recovery device, comprising a cylinder and at least two spray heat recovery units arranged in the cylinder. The tail gas is washed and purified by the spray heat recovery unit, so that the tail gas can be discharged up to standard.

[0004] The second object of the utility model is to provide a sludge drying system using the above-mentioned tail gas purification heat recovery device.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0006] A tail gas purification heat recovery device, comprising: a vertically arranged cylinder, the lower part of the cylinder is formed with an air inlet for receiving sludge drying tail gas and a liquid outlet for discharging liquid, and the upper part of the cylinder is formed with an air outlet for discharging purified gas to form a tail gas channel flowing from bottom to top; wherein the inside of the cylinder has at least two spray heat recovery units, the spray heat recovery unit comprises a heat exchange assembly and a spray assembly, the heat exchange assembly is composed of a plurality of heat exchange parts, and has a heat exchange medium inside, the spray assembly comprises a plurality of nozzles, and the direction of the nozzles is opposite to the flow direction of the tail gas.

[0007] Further, the number of the spray heat recovery units is three, and the three spray heat recovery units are arranged at intervals along the vertical direction of the cylinder body, and the spray assembly is located above the heat exchange assembly.

[0008] Further, the heat exchange part is a spiral heat exchange member, a sheet heat exchange member, a honeycomb heat exchange member or a fan-shaped heat exchange member.

[0009] Further, the heat exchange part is a spiral heat exchange member, the spiral heat exchange member is defined as a heat exchange coil and is arranged in a spiral around the central axis of the cylinder body, and the heat exchange medium inlet and the heat exchange medium outlet of the spiral heat exchange member extend to the outside of the cylinder body, respectively.

[0010] Further, a circulating water tank is arranged on the lower outer wall of the cylinder body, the circulating water tank comprises a tank body and a water pump arranged on the upper portion of the tank body, the upper portion of the tank body is formed with a liquid outlet, and the lower portion of the tank body is formed with a liquid inlet and a sewage outlet, the water pump is communicated with the spray assembly through the liquid outlet, and the liquid outlet is connected with the liquid inlet.

[0011] Further, a defoaming assembly is further arranged, the defoaming assembly is located below the heat exchange assembly, the defoaming assembly comprises a fixing frame fixed to the inner wall of the cylinder body and a plurality of defoaming spheres defined in the fixing frame, and the defoaming assembly is used for blocking the water carried by the tail gas when the tail gas is cleaned by the spray assembly.

[0012] Further, a spiral flow guide member for gas guiding is arranged on the lower inner wall of the cylinder body and is located near the gas inlet.

[0013] Further, a plurality of observation openings are arranged at intervals along the vertical direction of the outer wall of the cylinder body, and the observation openings correspond to the spray heat recovery units.

[0014] Further, the cylinder body comprises an inner cylinder body and an outer cylinder body, and the inner cylinder body and the outer cylinder body have a heat preservation layer therebetween.

[0015] A sludge drying system comprises: a sludge drying device having a tail gas outlet and a drying gas inlet; a heat exchange device having a hot end and a cold end, the sludge drying device being communicated with the cold end of the heat exchange device through the tail gas outlet, and the sludge drying device being communicated with the hot end of the heat exchange device through the drying gas inlet; and the tail gas purification heat recovery device according to the above, the tail gas purification heat recovery device being communicated with the cold end of the heat exchange device through the gas inlet.

[0016] The utility model has the advantages of:

[0017] The tail gas purification heat recovery device of the utility model adopts multistage purification structure, through arrangement multiple modularized spray heat recovery unit, can according to actual processing capacity flexible adjustment device scale, to meet the tail gas treatment demand under different working conditions. In each stage purification structure, all be provided with the heat exchange assembly and spray assembly of upper and lower arrangement. The nozzle of spray assembly is opposite to the tail gas flow direction, this increases gas-liquid contact time, thereby improves the removal efficiency of particulate matter and pollutants in tail gas. Meanwhile, the spiral flow guide near the gas inlet is further optimized gas flow path, makes tail gas evenly distribute in the device. The heat exchange assembly adopts spiral arrangement heat exchange coil, this increases the heat exchange area with tail gas, and then improves heat recovery efficiency. Through the circulation flow of heat exchange medium, the waste heat in tail gas is recovered and used for other process, effectively reduces energy consumption. In addition, the tail gas purification heat recovery device of the utility model is also provided with demisting component, and the demisting component is located below the heat exchange assembly, and the demishing ball body arranged in the demishing component can effectively prevent tail gas from taking away moisture during the purification process, thereby reducing the risk of secondary pollution. The utility model also constructs the circulating water system composed of circulating water tank and water pump, and the system ensures the continuous circulation of spray liquid in the device, reduces operation cost. Through the synergistic effect of the spray assembly, heat exchange assembly and demishing component, the tail gas heat can be effectively recovered, the temperature is reduced, the mist is removed, the gas volume is reduced, the amount is reduced, the processing efficiency is improved, the processing load of the rear end (such as deodorization equipment) is reduced, and the overall deodorization effect is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the tail gas purification heat recovery device of the utility model three-dimensional structure schematic diagram.

[0019] Figure 2 It is the tail gas purification heat recovery device of the utility model three-dimensional sectional view.

[0020] Figure 3 It is the three-dimensional structure schematic diagram of the three spray heat recovery units of the utility model.

[0021] Figure 4 It is the front view of the three spray heat recovery units of the utility model.

[0022] Figure 5 It is the three-dimensional structure schematic diagram of the heat exchange assembly and demishing component of the upper layer spray heat recovery unit and the spray assembly of the lower layer spray heat recovery unit.

[0023] Wherein, 1 is the cylinder, 1a is the outer cylinder, 1b is the inner cylinder, 1c is the insulation layer, 101 is the air inlet, 102 is the liquid outlet, 103 is the gas outlet, 104 is the spiral flow guide, 105 is the observation port, 106 is the reinforcing rib, 2 is the spray heat recovery unit, 201 is the fixed frame, 202 is the heat exchange assembly, 202a is the heat exchange coil, 202a1 is the heat exchange medium inlet, 202a2 is the heat exchange medium outlet, 203 is the spray assembly, 203a is the nozzle, 204 is the demister assembly, 204a is the demister ball, 3 is the circulating water tank, 301 is the tank, 301a is the liquid outlet, 301b is the sewage outlet, 301c is the liquid inlet, 302 is the water pump. DETAILED DESCRIPTION

[0024] The utility model will be combined with the specific implementation and the drawings to make further detailed explanation.

[0025] As Figure 1 shown, a tail gas purification heat recovery device mainly includes a vertically arranged cylinder 1, the cylinder 1 is cylindrical structure, can be integrally formed or formed in parts, in this embodiment, the cylinder 1 is integrally formed, and the reinforcing rib 106 is arranged on the outer wall of the cylinder 1 along its vertical direction and is spaced, for improving the rigidity of the cylinder 1, and in another embodiment, the cylinder 1 is formed in parts, the cylinder 1 can be divided into a plurality of sub-cylinder 1, each cylinder 1 is detachably connected together from bottom to top, the working volume inside the cylinder 1 can be adjusted according to the processing capacity of tail gas. Figure 1 , the lower part of the cylinder 1 is formed with the air inlet 101 for receiving sludge drying tail gas and the liquid outlet 102 for discharging liquid, the sludge drying tail gas is a gas with a certain temperature and with sludge dust, the air inlet 101 is located on the side wall of the lower part of the cylinder 1 and is communicated with the cold end of the heat exchange device or the gas outlet end of the sludge drying device through a pipeline, and the upper part of the cylinder 1 is formed with the gas outlet 103 for discharging purified gas, to form a tail gas channel flowing from bottom to top, the gas outlet 103 can be connected to the rear-end deodorization device or directly discharged to the external environment. In this embodiment, the gas outlet 103 is arranged at the top of the cylinder 1, and can also be arranged on the side wall of the upper part of the cylinder 1, the tail gas entering from the air inlet 101 can flow from bottom to top to the top of the cylinder 1 and be discharged from the gas outlet 103, to prolong the flow path of the tail gas in the cylinder 1 and improve the processing efficiency.

[0026] Referring to Figure 2As shown in the perspective cutaway view of the tail gas purification heat recovery device, the inside of the cylinder 1 has at least two spray heat recovery units 2, the number of spray heat recovery units 2 is 3, the 3 spray heat recovery units 2 are arranged on the inner wall of the cylinder 1 in the vertical direction of the cylinder at certain intervals and located between the gas inlet 101 and the gas outlet 103, so that the tail gas can flow from the bottom of the cylinder 1 upwards in turn through the three spray heat recovery units 2 and then discharged to the outside, so as to realize multi-stage water washing and heat exchange of the tail gas. Of course, the number of spray heat recovery units 2 can be configured as needed, for example, 2, 4, 6, etc.

[0027] Next, with reference to Figures 2-4, the spray heat recovery unit 2 comprises a heat exchange assembly 202 and a spray assembly 203, the spray assembly 203 is located above the heat exchange assembly 202, the spray assembly 203 is arranged near the upper spray heat recovery unit 2, and a certain space is left between the spray assembly 203 and the heat exchange assembly 202, so that the path of the spray liquid sprayed to the heat exchange assembly is longer and the contact is more sufficient. Of course, the spray assembly 203 can also be located below the heat exchange assembly 202 according to the needs, and the heat exchange assembly 202 is sprayed and washed by the spray assembly 203 located in the upper spray heat recovery unit 2. The heat exchange assembly 202 is composed of a plurality of heat exchange parts, which are spiral heat exchange parts, sheet heat exchange parts, honeycomb heat exchange parts or fan-shaped heat exchange parts. In this embodiment, the heat exchange part is a spiral heat exchange part, which is defined as a heat exchange coil 202a, the heat exchange coil 202a has a heat exchange medium inlet 202a1 and a heat exchange medium outlet 202a2, the heat exchange coil 202a is composed of a plurality of arc-shaped pipes, and the two adjacent arc-shaped pipes have a joint. The heat exchange coil 202a has heat exchange medium inside, which is used to recover heat from tail gas, wherein the heat exchange coil is arranged in a spiral around the central axis of the cylinder 1, and the heat exchange medium inlet 202a1 and the heat exchange medium outlet 202a2 of the heat exchange coil extend to the outside of the cylinder 1 respectively. Among them, the number of heat exchange coil 202a is 1, and it is communicated with the heat exchange coil 202a of another adjacent spray heat recovery unit 2, for example, the number of spray heat recovery units 2 is 3, the heat exchange medium inlet 202a1 of the heat exchange coil 202a located in the upper spray heat recovery unit 2 is connected with other external treatment equipment needing heat, while the heat exchange medium outlet 202a2 of the heat exchange coil 202a is connected with the heat exchange medium inlet 202a1 of the heat exchange coil 202a located in the middle layer spray heat recovery unit 2, the heat exchange medium inlet 202a1 of the heat exchange coil 202a located in the lower layer spray heat recovery unit 2 is connected with the heat exchange medium outlet 202a2 of the heat exchange coil 202a located in the middle layer spray heat recovery unit 2, and finally the heat exchange medium outlet 202a2 of the heat exchange coil 202a located in the lower layer spray heat recovery unit 2 is connected with other external treatment equipment needing heat, thereby constructing a heat exchange medium circulating heat exchange system. Of course, the heat exchange coil 202a of each spray heat recovery unit 2 can also be arranged as needed, for example, 2, 3, 5 and the like, and each heat exchange coil 202a is stacked together in turn from bottom to top and is in fluid communication to achieve heat exchange efficiency.

[0028] With reference to the above Figures 2-4The spray assembly 203 comprises a plurality of nozzles 203a arranged regularly or irregularly, the plurality of nozzles 203a are communicated with each other through a plurality of branch pipes, the plurality of branch pipes converge into a main pipe extending to the outside of the cylinder 1, the nozzles 203a are opposite to the flow direction of the tail gas, the tail gas is first sprayed and washed by the spray liquid sprayed by the plurality of nozzles 203a, and then flows through the heat exchange coil 202a to exchange heat with the heat exchange medium in the heat exchange coil 202a. In this embodiment, the number of the spray heat recovery units 2 is 3, and three groups of nozzle 203a arrays are formed, the main pipes of each group of nozzle 203a array extend to the outside of the cylinder 1 and are connected together, so that the spray liquid is synchronously delivered to each group of nozzles 203a through the external pressurizing device, the main pipe and the branch pipe to wash the tail gas.

[0029] With reference to Figure 1 and Figure 2 , the lower outer wall of the cylinder 1 is provided with a circulating water tank 3 for providing spray liquid for the spray assembly 203, the circulating water tank 3 comprises a tank body 301 and a water pump 302 arranged at the upper part of the tank body 301, the tank body 301 is loaded with spray liquid, wherein the spray liquid can be water, ionized water, cleaning liquid or acid-base liquid, etc. The upper part of the tank body 301 is formed with a liquid outlet 301a, one end of the water pump 302 extends below the liquid level in the tank body 301, the other end of the water pump 302 is communicated with the main pipe of the spray assembly 203 through the liquid outlet 301a, the lower part of the tank body 301 is formed with a liquid inlet 301c and a sewage outlet 301b, the liquid outlet 102 is connected with the liquid inlet 301c, during operation, the water pump 302 extracts the spray liquid in the tank body 301, and delivers the spray liquid to the nozzles 203a through the main pipe and the branch pipe of the spray assembly 203, under the pressurizing action of the nozzles 203a, the spray liquid is sprayed into the inside of the cylinder 1, and then flows from top to bottom to the bottom of the cylinder 1, and then returns to the tank body 301 through the liquid outlet 102 and the liquid inlet 301c for recycling. If the impurities in the spray liquid in the tank body 301 are too much, the water pump 302 can be stopped and the sewage outlet 301b is opened to discharge the liquid, and then new spray liquid is supplemented, so as to construct a spray water circulation system.

[0030] As Figures 2-5As shown, the cylinder 1 is provided with a demisting assembly 204 below the heat exchange assembly 202. The demisting assembly 204 includes a fixed frame 201 fixed to the inner wall of the cylinder and a plurality of demisting spheres 204a defined in the fixed frame. The demisting spheres 204a are polyhedral hollow plastic spheres, and their main function is to attach the mist carried in the tail gas to the polyhedral hollow plastic spheres by inertial collision when the tail gas is washed by the spray assembly 203, to form larger droplets and fall down, thereby achieving the effect of demisting. The fixed frame 201 is composed of a first frame body and a second frame body arranged above and below, and the shapes of the two are matched with the cylinder 1 and fixed to the inner wall of the cylinder. The first frame body and the second frame body are both provided with a plurality of communication ports, and the plurality of demisting spheres 204a are located between the first frame body and the second frame body. The heat exchange coil 202a and the nozzle 203a are both located above the first frame body, and the coverage area of the heat exchange coil 202a is approximately the same as the area of the first frame body. The tail gas is first washed by the spray liquid sprayed by the nozzle 203a, and the impurities in the tail gas are removed. Subsequently, the tail gas contacts the demisting spheres 204a, and the water vapor is attached to the demisting spheres. Then, the tail gas contacts the heat exchange coil 202a and exchanges heat with the heat exchange medium therein. After that, the tail gas enters the upper spray heat recovery unit 2 through the nozzle 203a and repeats the above process. Finally, the purified gas is discharged from the gas outlet 103 at the top of the cylinder 1 to the outside. Such arrangement makes the tail gas first undergo water washing and then undergo heat exchange with the heat exchange coil 202a, avoiding corrosion of the heat exchange coil by corrosive impurities in the tail gas. At the same time, the water washed liquid still carries some heat and can flow through the heat exchange coil 202a for secondary heat exchange, thereby improving the heat exchange efficiency. In addition, the position of the demisting assembly 204 can be adjusted according to actual needs, for example, it can be placed between the heat exchange assembly 202 and the spray assembly 203.

[0031] With reference back to Figures 2-5 , the lower inner wall of the cylinder 1 is provided with a spiral flow guide 104 for gas guiding near the gas inlet 101, and the spiral flow guide 104 includes a plurality of spiral vanes. In this embodiment, the number of spiral vanes is 2. The spiral flow guide 104 makes the gas flow path longer by setting spiral vanes on the inner wall of the cylinder 1, increases the residence time of the tail gas in the cylinder 1, reduces the wind speed, and further improves the spray water washing effect and heat exchange efficiency.

[0032] With reference back to Figure 2 , the outer wall of the cylinder 1 is provided with a plurality of observation ports 105 at certain intervals along its vertical direction, and each observation port 105 corresponds to one spray heat recovery unit 2. The number of observation ports 105 is 3, and the 3 observation ports 105 correspond to the 3 spray heat recovery units 2 one by one, which facilitates observation of the spray heat exchange condition.

[0033] With reference back to Figure 2The cylinder body 1 comprises an inner cylinder body 1b and an outer cylinder body 1a, and a sandwich layer is formed between the inner cylinder body 1b and the outer cylinder body 1a, and the sandwich layer is provided with a heat preservation layer 1c, which can reduce the heat loss of the tail gas.

[0034] In an embodiment not shown, a spraying pipe is further arranged on the inner side wall of the upper part of the cylinder body 1, and the spraying end of the spraying pipe faces the spraying heat recovery unit 2 located below. Through the arrangement of the spraying pipe, the effect of water washing and purification of the tail gas is further ensured, and the heat exchange assembly 202 of the spraying heat recovery unit 2 located in the uppermost layer can also be cleaned.

[0035] In an embodiment not shown, a sludge drying system mainly comprises a sludge drying device, a heat exchange device and the above-mentioned tail gas purification heat recovery device. The sludge drying device has a tail gas outlet and a drying gas inlet, and has a sludge inlet and a sludge outlet. The sludge to be treated enters the internal space from the sludge inlet, and the drying gas is introduced from the drying gas inlet to directly dry the sludge. The dried sludge is discharged from the sludge outlet, and the dried gas is discharged from the tail gas outlet.

[0036] The heat exchange device comprises a cold end and a hot end. The sludge drying device is in communication with the cold end of the heat exchange device through the tail gas outlet, and the sludge drying device is in communication with the hot end of the heat exchange device through the drying gas inlet. The tail gas purification heat recovery device is in communication with the cold end of the heat exchange device through the gas inlet 101. Thus, through the heat exchange device, the tail gas is subjected to primary treatment and heat exchange, and then enters the tail gas purification heat recovery device for secondary treatment and heat exchange, so as to improve the heat recovery efficiency. The heat exchange device mainly comprises an evaporator, a compressor, a condenser, a throttling device and a heat exchange medium flowing therebetween. The cold end of the heat exchange device comprises the evaporator, and the hot end of the heat exchange device comprises the condenser.

[0037] In summary, the tail gas purification heat recovery device adopts a multi-stage purification structure, and through arrangement of multiple modularized spray heat recovery units, the device scale can be flexibly adjusted according to the actual processing capacity, so as to meet the tail gas treatment demand under different working conditions. In each stage of the purification structure, a heat exchange assembly and a spray assembly arranged in an up-down mode are arranged. The nozzle of the spray assembly is opposite to the tail gas flow direction, which increases the gas-liquid contact time, thereby improving the removal efficiency of particulate matters and pollutants in the tail gas. Meanwhile, the spiral flow guide member arranged near the gas inlet further optimizes the gas flow path, so that the tail gas is uniformly distributed in the device. The heat exchange assembly adopts a spiral-shaped heat exchange coil, which increases the heat exchange area with the tail gas, thereby improving the heat recovery efficiency. Through circulation of the heat exchange medium, the waste heat in the tail gas is recovered and used for other processes, effectively reducing the energy consumption. In addition, the tail gas purification heat recovery device of the utility model is also provided with a demisting assembly, the demisting assembly is located below the heat exchange assembly, and the demisting balls arranged in the demisting assembly can effectively prevent the tail gas from taking away water during the purification process, thereby reducing the risk of secondary pollution. The utility model also constructs a circulating water system composed of a circulating water tank and a water pump, which ensures the continuous circulation of the spray liquid in the device, reducing the operation cost. Through the synergistic effect of the spray assembly, the heat exchange assembly and the demisting assembly, the tail gas heat can be effectively recovered, the temperature can be reduced, the mist can be removed, and the gas volume can be reduced, so as to achieve the purpose of reducing the amount, thereby improving the treatment efficiency, reducing the load of the rear-end treatment (such as deodorization equipment), and enhancing the overall deodorization effect.

[0038] The above embodiments are the preferred embodiments of the utility model, but the embodiments of the utility model are not limited by the above embodiments, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the utility model should be equivalent replacement methods, all of which are included in the protection scope of the utility model. The described embodiments of the disclosure are intended to serve as non-limiting examples, and other embodiments can take various and alternative forms. In addition, the drawings are not necessarily to scale and can present some simplified representations of various features of the disclosure, including, for example, specific dimensions, directions, positions, and shapes. Details associated with such features will be determined in part by the intended application and use environment of the described embodiments.

[0039] The detailed description and the accompanying drawings or diagrams support and describe the present teachings, but the scope of the present teachings is limited only by the claims. Although some of the best modes and other embodiments for carrying out the present teachings have been described in detail, various alternative designs and embodiments exist for practicing the present teachings defined in the appended claims. Furthermore, the disclosure expressly includes combinations and subcombinations of the elements and features set forth above and below.

Claims

1. A tail gas purification heat recovery apparatus characterized by comprising: include: A vertically arranged cylinder has an air inlet at the bottom for receiving sludge drying exhaust gas and a liquid outlet at the top for discharging liquid, forming an exhaust gas channel that flows from bottom to top. The cylinder has at least two spray heat recovery units inside. Each spray heat recovery unit includes a heat exchange component and a spray component. The heat exchange component is composed of multiple heat exchange parts and contains a heat exchange medium. The spray component includes multiple nozzles, and the nozzles are oriented in the opposite direction to the flow direction of the exhaust gas.

2. The exhaust gas purification heat recovery device according to claim 1, characterized by The number of spray heat recovery units is three, and the three spray heat recovery units are arranged at certain intervals along the vertical direction of the cylinder; the spray assembly is located above the heat exchange assembly.

3. The exhaust gas purification heat recovery device according to claim 1, characterized by The heat exchange section is a spiral heat exchanger, a plate heat exchanger, a honeycomb heat exchanger, or a fan-shaped heat exchanger.

4. The exhaust gas purification heat recovery device according to claim 1 or 2, characterized by The heat exchange section is a spiral heat exchange element, which is defined as a heat exchange coil and is arranged spirally around the central axis of the cylinder. Its heat exchange medium inlet and heat exchange medium outlet extend to the outside of the cylinder, respectively.

5. The exhaust gas purification heat recovery device according to claim 1, characterized by A circulating water tank is provided on the lower outer wall of the cylinder. The circulating water tank includes a tank body and a water pump located on the upper part of the tank body. The upper part of the tank body has an outlet, and the lower part has an inlet and a drain. The water pump is connected to the spray assembly through the outlet, and the drain is connected to the inlet.

6. The exhaust gas purification heat recovery device according to claim 1, characterized by A demisting assembly is also provided, which is located below the heat exchange assembly. The demisting assembly includes a fixing frame fixed to the inner wall of the cylinder and a plurality of demisting balls confined within the fixing frame. It is used to prevent the exhaust gas from carrying away moisture when the exhaust gas is cleaned by the spray assembly.

7. The exhaust gas purification heat recovery device according to claim 1, characterized by A spiral guide for gas guidance is provided on the lower inner wall of the cylinder and is located near the air inlet.

8. The exhaust gas purification heat recovery device according to claim 1, characterized by The outer wall of the cylinder is provided with a plurality of observation ports at certain intervals along its vertical direction, and the observation ports correspond to the spray heat recovery unit.

9. The exhaust gas purification heat recovery device according to claim 1, characterized by The cylinder includes an inner cylinder and an outer cylinder, with an insulation layer between the inner cylinder and the outer cylinder.

10. A sludge dewatering system characterized by, include: The sludge drying device has an exhaust gas outlet and a drying gas inlet; A heat exchange device having a hot end and a cold end, wherein the sludge drying device is connected to the cold end of the heat exchange device through the exhaust gas outlet, and the sludge drying device is connected to the hot end of the heat exchange device through the drying gas inlet; According to any one of claims 1 to 9, the exhaust gas purification heat recovery device is connected to the cold end of the heat exchange device through the air inlet.

Images