Anti-corrosion energy-saving system for sludge drying

Abstract

The anti-corrosion energy-saving system comprises a machine shell, a heat recovery unit, a temperature increasing unit and a sludge purification unit, the heat recovery unit, the temperature increasing unit and the sludge purification unit are arranged in the machine shell, and an air return opening and an air supply opening are formed in the machine shell; the heat recovery unit comprises a pre-cooling part and a reheating part, the temperature increasing unit comprises a first compressor, a first condenser, a first throttling valve and a first evaporator, and the sludge purification unit comprises a low-temperature plasma purification assembly and an activated carbon purification assembly. Exhaust air of the sludge drying line sequentially passes through the air return opening, the pre-cooling part, the low-temperature plasma purification assembly, the first evaporator, the activated carbon adsorber, the reheating part, the first condenser and the air supply opening, is subjected to humidity reduction and temperature increase and then is sent back to the sludge drying line. The anti-corrosion energy-saving system for sludge drying has the advantages that waste gas of a sludge drying line can be recycled, a dry and hot clean air heat source is provided for the sludge drying line, and the anti-corrosion energy-saving system has a good energy-saving effect and anti-corrosion performance.

Description

Technical Field

[0001] The invention relates to the technical field of energy-saving air conditioning equipment, and in particular to an anti-corrosion and energy-saving system for sludge drying. Background Art

[0002] Sludge drying is an important technology in the sludge disposal technology route. The difficulty of sludge disposal is to reduce the moisture content. After dehydration, the moisture content of sludge is reduced from 80% to 30%, and the total amount is reduced by 71%. Sludge drying is the most direct way to reduce sludge. The products after sludge drying also create conditions for carbonization and resource utilization. At present, the equipment used for sludge drying on the market generally has high investment costs, and the existing sludge drying equipment generally adopts technology similar to chemical drying equipment, and has not carried out technical settings to reduce energy consumption. The operating cost and energy consumption exceed the company's ability to bear, and the excessive energy consumption does not meet the requirements of energy conservation and emission reduction in my country; these characteristics have greatly limited the application of sludge drying technology.

[0003] Existing equipment for drying sludge by low temperature heating adopts heat recovery technology, and the fully enclosed drying mode does not emit any waste gas. The low temperature heating technology accelerates the rapid evaporation of water in the sludge and improves the sludge treatment effect. However, the sludge contains a large amount of fungi, microorganisms, heavy metals, and inorganic substances, and the sludge usually has a certain acidity or alkalinity. In the low temperature heating sludge drying equipment, the recovered sludge waste gas passes through the heat exchange components in the equipment, which is easy to corrode the heat exchange components, so that the equipment can no longer be used.

[0004] In the patent with publication number CN216711889U, a "modular mesh belt type sludge low temperature drying treatment equipment with high anti-corrosion structure design" is disclosed. The windward surface of the unit condenser and evaporator is set in an independent air duct, so the welding port and pipeline, compressor, liquid storage tank, expansion valve, etc. are separated from the air duct and have independent chambers, wherein the compressor chamber is below the unit, which can effectively reduce the corrosion hazard of corrosive gas in the sludge drying process and improve the life and durability of the whole machine parts. The equipment has the following problems: in the closed-loop heating main section, since fungi and microorganisms cannot be processed by the filter, the acidic or alkaline air carrying these substances will pass through the condenser and evaporator. These corrosive substances circulate in the closed-loop heating main section and are easily attached to the condenser and evaporator. After a certain period of time, the condenser and evaporator will still be corroded, and the pipeline of the heat exchanger is in a corrosive environment for a long time, and the refrigerant in the pipeline is easy to leak, which requires a lot of manpower to repair or replace parts, increasing the maintenance cost of the equipment.

[0005] To this end, we proposed an anti-corrosion and energy-saving system for sludge drying. Summary of the invention

[0006] The purpose of the present invention is to provide an anti-corrosion and energy-saving system for sludge drying, which can recycle the exhaust gas of the sludge drying line, provide a dry hot clean air heat source for the sludge drying line, and has good energy-saving effect and anti-corrosion performance.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A corrosion-proof and energy-saving system for sludge drying comprises: a casing and a heat recovery unit, a temperature increase unit and a sludge purification unit arranged in the casing; the casing is provided with a return air port and an air supply port; the heat recovery unit comprises a heat recovery heat exchanger, and the heat recovery heat exchanger comprises a pre-cooling part and a reheating part; the temperature increase unit comprises a temperature increase module, and the temperature increase module comprises a first compressor, a first condenser, a first throttle valve and a first evaporator connected by a copper tube; the sludge purification unit comprises a low-temperature plasma purification component and an activated carbon purification component, and the low-temperature plasma purification component comprises a low-temperature plasma generator, and the activated carbon purification component comprises an activated carbon adsorber.

[0009] The return air inlet is connected to the air outlet of the sludge drying line, and the air supply outlet is connected to the air inlet of the sludge drying line. The exhaust air of the sludge drying line passes through the return air inlet, the precooling part, the low-temperature plasma purification component, the first evaporator, the activated carbon adsorber, the reheating part, the first condenser, and the air supply outlet in sequence, and is sent back to the sludge drying line after dehumidification and temperature increase. The precooling part, the first evaporator, the reheating part and the first condenser are treated with anti-corrosion. A compressor cavity is provided in the casing, and the compressor cavity is separated from the path of the exhaust air of the sludge drying line.

[0010] Furthermore, the activated carbon purification component also includes an activated carbon desorption device.

[0011] Furthermore, the activated carbon desorption device includes a second compressor, a second condenser, a second throttle valve and a second evaporator connected by a copper tube. The second evaporator is arranged between the activated carbon adsorber and the reheat part. A bypass air duct is provided in the casing, and a bypass air valve is provided at the air inlet of the bypass air duct. The second condenser is arranged in the bypass air duct. There are two activated carbon adsorbers, namely a first activated carbon adsorber and a second activated carbon adsorber. A fresh air valve is provided on the casing. The exhaust air of the sludge drying line passes through the return air port, the precooling part, the low-temperature plasma purification component, the first evaporator, the first activated carbon adsorber in turn, and is mixed with the fresh air. After passing through the second evaporator, the reheat part and the first condenser, part of the air is sent back to the sludge drying line through the air supply port, and the other part of the air is sent to the second activated carbon adsorber through the second condenser.

[0012] Furthermore, a first activated carbon air duct and a second activated carbon air duct are provided in the casing, and a first main air inlet valve, a first main air outlet valve, a first bypass air inlet valve and a first bypass air outlet valve are correspondingly provided on the first activated carbon air duct, and a second main air outlet valve, a second bypass air inlet valve and a second bypass air outlet valve are correspondingly provided on the second activated carbon air duct, the first activated carbon adsorber is located in the first activated carbon air duct, and the second activated carbon adsorber is located in the second activated carbon air duct, the opening and closing states of the first main air inlet valve, the first main air outlet valve, the second bypass air inlet valve and the second bypass air outlet valve are consistent, and the opening and closing states of the second main air inlet valve, the second main air outlet valve, the first bypass air inlet valve and the first bypass air outlet valve are consistent.

[0013] Furthermore, the second evaporator and the second condenser are subjected to anti-corrosion treatment.

[0014] Furthermore, the first bypass gas outlet valve and the second bypass gas outlet valve are both connected to the catalytic combustion furnace.

[0015] Furthermore, the wind direction of the exhaust air of the sludge drying line passing through the activated carbon adsorber when undergoing adsorption treatment is opposite to the wind direction of the exhaust air of the sludge drying line passing through the activated carbon adsorber when undergoing desorption treatment.

[0016] Furthermore, an auxiliary heating device is provided in the bypass air duct.

[0017] Furthermore, the heat recovery heat exchanger is a heat pipe heat recovery device.

[0018] Furthermore, an air filter is provided at the return air outlet.

[0019] The present invention includes a casing and a heat recovery unit, a heating unit and a sludge purification unit arranged in the casing. The casing is provided with a return air port and an air supply port; the heat recovery unit includes a precooling part and a reheating part, the heating unit includes a first compressor, a first condenser, a first throttle valve and a first evaporator, the sludge purification unit includes a low-temperature plasma purification component and an activated carbon purification component, and the exhaust air of the sludge drying line passes through the return air port, the precooling part, the low-temperature plasma purification component, the first evaporator, the activated carbon adsorber, the reheating part, the first condenser, and the air supply port in sequence, and is sent back to the sludge drying line after dehumidification and temperature increase. The anti-corrosion and energy-saving system for sludge drying has the advantages of being able to recycle the exhaust gas of the sludge drying line, first subjecting the exhaust gas of the sludge drying line to three-stage cooling and dehumidification, purification through the low-temperature plasma purification component and the activated carbon purification component, and then two-stage temperature increase, providing a dry hot clean air heat source for the sludge drying line, and having good energy-saving effect and anti-corrosion performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1It is a schematic diagram of the system principle of the first embodiment of the anti-corrosion and energy-saving system for sludge drying;

[0021] Figure 2 A schematic diagram of the system principle of a second embodiment of an anti-corrosion and energy-saving system for sludge drying;

[0022] Figure 3 A top view of the third embodiment of the anti-corrosion and energy-saving system for sludge drying, with the top of the housing hidden;

[0023] Figure 4 for Figure 3 AA section view;

[0024] Figure 5 for Figure 3 BB section view;

[0025] Figure 6 for Figure 3 CC section view. DETAILED DESCRIPTION

[0026] The present invention provides an anti-corrosion and energy-saving system for sludge drying. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0027] The present invention provides an anti-corrosion and energy-saving system for sludge drying, the structure of which is as follows: Figure 1-Figure 6 As shown, it includes: a housing 1 and a heat recovery unit 2, a temperature increasing unit 3 and a sludge purification unit 4 arranged in the housing 1. Figure 1In the first embodiment shown, the housing 1 is provided with a return air port 11 and an air supply port 12 . The heat recovery unit 2 includes a heat recovery heat exchanger 21, which includes a pre-cooling part 211 and a reheating part 212; the temperature increasing unit 3 includes a temperature increasing module 31, which includes a first compressor 311, a first condenser 312, a first throttle valve 313 and a first evaporator 314 connected by a copper tube. The refrigerant circulates in the first compressor 311, the first condenser 312, the first throttle valve 313 and the first evaporator 314 along the copper tube. The first compressor 311 converts the low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant. After the refrigerant reaches the first condenser 312, it transfers heat to the air passing through the first condenser 312. The refrigerant is cooled and condensed into a liquid. After throttling by the first throttle valve 313, the refrigerant is converted into a low-pressure liquid refrigerant, and then absorbs the heat of the air passing through the first evaporator 314. The refrigerant is converted into a low-temperature and low-pressure gaseous refrigerant and returns to the first compressor 311 to continue circulating. Thus, the temperature of the air passing through the first condenser 312 increases, and the temperature of the air passing through the first evaporator 314 decreases.

[0028] The sludge purification unit 4 includes a low-temperature plasma purification component 41 and an activated carbon purification component 42. The low-temperature plasma purification component 41 includes a low-temperature plasma generator. The suitable ambient temperature of the low-temperature plasma generator is 40°C-60°C. The positive ions and negative ions simultaneously generated by the low-temperature plasma generator generate huge energy release at the moment of neutralization of positive and negative charges in the air, thereby causing changes in the structure of bacteria around them or energy conversion, thereby causing the death of bacteria and achieving its sterilization effect. The activated carbon purification component 42 includes an activated carbon adsorber 421. The suitable ambient temperature for the adsorption work of the activated carbon adsorber 421 is 20°C-40°C. The activated carbon can effectively adsorb acidic or alkaline components in the exhaust gas.

[0029] The return air port 11 is connected to the air outlet of the sludge drying line 5, and the air supply port 12 is connected to the air inlet of the sludge drying line 5. The exhaust air of the sludge drying line 5 passes through the return air port 11, the precooling part 211, the low-temperature plasma purification component 41, the first evaporator 314, the activated carbon adsorber 421, the reheating part 212, the first condenser 312, the air supply port 12 in sequence, and is sent back to the sludge drying line 5 after dehumidification and temperature increase. The trajectory of the exhaust air of the sludge drying line 5 is as follows: Figure 1As shown: A1→A2→A3→A4. The exhaust air of the sludge drying line 5 has a higher temperature when passing through the precooling section 211, and has a lower temperature after being cooled and dehumidified by the first evaporator 314. In this way, the higher temperature air passing through the precooling section 211 and the lower temperature air passing through the reheating section 212 are heat exchanged through the heat recovery heat exchanger 21. The air passing through the precooling section 211 is cooled, and the air passing through the reheating section 212 is heated. In this way, the waste heat of the sludge drying line 5 is recovered, the waste gas of the sludge drying line 5 is cooled and dehumidified, and then the waste gas is heated and sent back to the sludge drying line 5 for the drying process, which has a good energy-saving effect.

[0030] The precooling part 211, the first evaporator 314, the reheating part 212 and the first condenser 312 are treated with anti-corrosion, and a compressor cavity 17 is provided in the casing 1, and the compressor cavity 17 is separated from the path of the exhaust air of the sludge drying line 5. The existing anti-corrosion treatment method is generally to dip the surface into an anti-corrosion coating, but in order to ensure that the heat exchange efficiency of the heat exchanger is not lost too much, the material and thickness of the anti-corrosion coating are required to be high, so that the anti-corrosion coating cannot completely prevent the heat exchanger from being corroded, but it can delay the corrosion of the heat exchanger. The first compressor 311, the first throttle valve 313 and other components that do not need to exchange heat with the air are placed in the compressor cavity 17, which effectively prevents the first compressor 311, the first throttle valve 313 and other components from being corroded by the exhaust air of the sludge drying line 5.

[0031] The anti-corrosion and energy-saving system for sludge drying provided by the present invention provides a heat source temperature of about 70°C to the sludge drying line 5, and the return air temperature returning from the sludge drying line 5 to the anti-corrosion and energy-saving system for sludge drying provided by the present invention is about 60°C. After preliminary cooling and dehumidification by the pre-cooling part 211, the exhaust gas temperature is cooled to about 40°C, and the exhaust gas is sterilized by a low-temperature plasma generator. In such an environment, the heat dissipation and sterilization effects of the low-temperature plasma generator are better. The exhaust gas is further cooled and dehumidified by the first evaporator 314, and the exhaust gas temperature is cooled to about 30°C. The activated carbon adsorber 421 adsorbs the acidic or alkaline substances in the exhaust gas. The purified exhaust gas passes through the reheating part 212 and the first condenser 312, and is heated twice to about 70°C and sent to the sludge drying line 5 to continue drying the sludge. The anti-corrosion and energy-saving system for sludge drying provided by the present invention can not only recycle the waste heat of the sludge drying line 5, recycle the waste heat of the sludge drying line 5, use the heat pump technology to provide the sludge drying line 5 with a high-temperature heat source for drying the sludge, and dehumidify the waste heat to reduce the air humidity of the sludge drying line 5, which has a good energy-saving effect and improves the efficiency of sludge drying. It also purifies the air passing through the system, reduces corrosive substances in the air, makes the heat exchange components have better durability, and reduces the maintenance cost of the anti-corrosion and energy-saving system.

[0032] Specifically, Figure 2In the second embodiment shown, the activated carbon purification component 42 further includes an activated carbon desorption device 422. Since the concentration of harmful substances in the sludge is generally high, the activated carbon adsorber 421 needs to be replaced more frequently. The activated carbon desorption device 422 is used to desorb the used activated carbon adsorber 421, so that the activated carbon adsorber 421 can be regenerated and reused, which effectively reduces the cost of the activated carbon adsorber 421.

[0033] Specifically, the activated carbon desorption device 422 includes a second compressor 422a, a second condenser 422b, a second throttle valve 422c and a second evaporator 422d connected by a copper tube, the second evaporator 422d is arranged between the activated carbon adsorber 421 and the reheating part 212, a bypass air duct 13 is arranged in the casing 1, and a bypass air valve 131 is arranged at the air inlet of the bypass air duct 13, the second condenser 422b is arranged in the bypass air duct 13, and the activated carbon adsorber 421 is provided with two, namely, a first activated carbon adsorber 421a and a second activated carbon adsorber 421d. The first activated carbon adsorber 421b is provided with a fresh air valve 14 on the housing 1, and the fresh air valve 14 can be arranged before the reheating part 212. In the anti-corrosion and energy-saving system for sludge drying provided by the present invention, the fresh air valve 14 is arranged between the first activated carbon adsorber 421a and the second evaporator 422d. The fresh air with a lower temperature enters the housing 1 after being filtered, and is mixed with the exhaust air of the sludge drying line 5 that has been cooled and treated. After cooling and dehumidifying again by the second evaporator 422d, it enters the reheating part 212 and exchanges heat with the exhaust air of the sludge drying line 5, that is, the trajectory of the fresh air is as follows: Figure 2 As shown: C1→C2→C3. The exhaust air of the sludge drying line 5 passes through the return air port 11, the precooling part 211, the low-temperature plasma purification component 41, the first evaporator 314, the first activated carbon adsorber 421a, and is mixed with the fresh air. After passing through the second evaporator 422d, the reheating part 212, and the first condenser 312, a part of the air is sent back to the sludge drying line 5 through the air supply port 12. Its trajectory is as shown in the figure. Figure 2 As shown: B1→B2→B3→B4→B5→B6→B7, another part of the air is sent to the second activated carbon adsorber 421b through the second condenser 422b, and its trajectory is as follows Figure 2 As shown: B1→B2→B3→B4→B5→B6→B8→B9.

[0034] When the second activated carbon adsorber 421b needs to be desorbed, the second compressor 422a is started, the bypass valve 131 and the fresh air valve 14 are opened, and the refrigerant circulates in the system consisting of the second compressor 422a, the second condenser 422b, the second throttle valve 422c and the second evaporator 422d connected by the copper tube. The refrigerant in the second condenser 422b releases heat, causing the temperature of the air passing through the second condenser 422b to rise, and the refrigerant in the second evaporator 422d absorbs heat, causing the temperature of the air passing through the second evaporator 422d to drop. The exhaust air of the sludge drying line 5 is sequentially cooled and dehumidified by the precooling part 211, the first evaporator 314, and the second evaporator 422d in three stages, so that the moisture content of the air sent to the sludge drying line 5 is extremely low, which effectively improves the drying efficiency of the sludge drying line 5. After the air is heated in three stages, namely, the reheating section 212, the first condenser 312, and the second condenser 422b, it is sent to the second activated carbon adsorber 421b for desorption treatment. In this way, a high-temperature heat source can be provided to the sludge drying line 5, and a higher-temperature heat source can be provided to the second activated carbon adsorber 421b, so that the activated carbon in the second activated carbon adsorber 421b can be regenerated, thereby saving the energy consumption of the activated carbon desorption device 422. In this way, the functions of the entire anti-corrosion and energy-saving system are diversified, and a better energy-saving effect is achieved.

[0035] Specifically, after the first activated carbon adsorber 421a has been used for a period of time, it is necessary to exchange the positions of the first activated carbon adsorber 421a and the second activated carbon adsorber 421b to perform a desorption process on the first activated carbon adsorber 421a. Figure 3-Figure 6 In the third embodiment shown in the figure, the interior of the casing 1 is a separated upper and lower structure, and a first activated carbon air duct 15 and a second activated carbon air duct 16 are provided in the casing 1. The first activated carbon air duct 15 is correspondingly provided with a first main air inlet valve 151, a first main air outlet valve 152, a first bypass air inlet valve 153 and a first bypass air outlet valve 154, and the second activated carbon air duct 16 is correspondingly provided with a second main air inlet valve 161, a second main air outlet valve 162, a second bypass air inlet valve 163 and a second bypass air outlet valve 164, and the activated carbon adsorber 421 is provided with two, and the first ... An activated carbon adsorber 421a is located in the first activated carbon air duct 15, and the second activated carbon adsorber 421b is located in the second activated carbon air duct 16. The opening and closing states of the first main air intake valve 151, the first main air outlet valve 152, the second bypass air intake valve 163 and the second bypass air outlet valve 164 are consistent. The opening and closing states of the second main air intake valve 161, the second main air outlet valve 162, the first bypass air intake valve 153 and the first bypass air outlet valve 154 are consistent. When the anti-corrosion and energy-saving system is working, the opening and closing states of the first main air intake valve 151 and the second main air intake valve 161 are inconsistent.

[0036] When the first activated carbon adsorber 421a in the first activated carbon air duct 15 performs adsorption treatment and the second activated carbon adsorber 421b in the second activated carbon air duct 16 performs desorption treatment, the first main air inlet valve 151, the first main air outlet valve 152, the second bypass air inlet valve 163 and the second bypass air outlet valve 164 are opened, and the second main air inlet valve 161, the second main air outlet valve 162, the first bypass air inlet valve 153 and the second bypass air outlet valve 154 are closed. Figure 3-Figure 6 As shown, the fresh air is mixed with the exhaust air of the sludge drying line 5 at F06 (E1), and the trajectory of the fresh air is: E1→E2→E3, and the trajectory of part of the exhaust air of the sludge drying line 5 is: F01→F02→F03→F04→F05→F06→F07→F08, and is sent back to the sludge drying line 5, and the trajectory of the other part of the exhaust air of the sludge drying line 5 is: F01→F02→F03→F04→F05→F06→F07→F09→F10→F11→F12→F13, which is used to desorb the second activated carbon adsorber 421b. When the first activated carbon adsorber 421a in the first activated carbon air duct 15 performs desorption treatment and the second activated carbon adsorber 421b in the second activated carbon air duct 16 performs adsorption treatment, the first main air inlet valve 151, the first main air outlet valve 152, the second bypass air inlet valve 163 and the second bypass air outlet valve 164 are closed, and the second main air inlet valve 161, the second main air outlet valve 162, the first bypass air inlet valve 153 and the second bypass air outlet valve 154 are opened. In this way, it is only necessary to control the opening and closing of each valve through the circuit, without changing the position of the first activated carbon adsorber 421a and the second activated carbon adsorber 421b, thereby reducing the maintenance time of the anti-corrosion and energy-saving system.

[0037] Specifically, the second evaporator 422d and the second condenser 422b are treated with anti-corrosion. The anti-corrosion level of the pre-cooling unit 211 and the first evaporator 314 can be higher than that of the second evaporator 422d, the reheating unit 212, the first condenser 312 and the second condenser 422b, so that all heat exchangers can provide sufficient heat exchange efficiency, the anti-corrosion and energy-saving system has good durability, and the cost of the anti-corrosion and energy-saving system is reduced.

[0038] Specifically, the first bypass outlet valve 154 and the second bypass outlet valve 164 are both connected to the catalytic combustion furnace 6, which converts the desorbed high-concentration exhaust gas into carbon dioxide and water through an oxidation reaction with a catalyst, and the exhaust gas after oxidation and decomposition meets the emission standards. The first bypass outlet valve 154 and the second bypass outlet valve 164 can also be connected to other exhaust gas treatment devices to allow the exhaust gas to be discharged after being treated to meet the standards.

[0039] Specifically, the wind direction of the exhaust air of the sludge drying line 5 passing through the activated carbon adsorber 421 when the exhaust air of the sludge drying line 5 is subjected to adsorption treatment is opposite to the wind direction of the exhaust air of the sludge drying line 5 passing through the activated carbon adsorber 421 when the exhaust air of the sludge drying line 5 is subjected to desorption treatment. In this way, the desorption effect on the activated carbon adsorber 421 is enhanced, and the desorption efficiency of the activated carbon is improved.

[0040] Specifically, an auxiliary heating device 132 is provided in the bypass air duct 13. The suitable temperature for desorption of activated carbon is 80°C-150°C. The auxiliary heating device 132 can be an electric heating device, or a heat exchanger for recovering waste heat from the catalytic combustion furnace 6, so as to avoid the situation where the air temperature reaching the desorbed activated carbon adsorber 421 is insufficient under low temperature conditions, thereby ensuring more complete desorption of activated carbon.

[0041] Specifically, the heat recovery heat exchanger 21 is a heat pipe heat recovery device. One end of the heat pipe heat recovery device is an evaporation section, and the other end is a condensation section. When one end of the heat pipe heat recovery device is heated, the liquid evaporates rapidly, and the steam flows to the other end under the action of a small pressure difference, and releases heat in the condensation section and condenses into liquid again. The liquid then flows back to the evaporation end along the porous material by capillary action and gravity, and the cycle continues in this way, so that heat can be transferred continuously. The heat pipe heat recovery device has the advantages of small size, high heat exchange efficiency, and easy maintenance.

[0042] Specifically, an air filter 18 is provided at the return air port 11. The air filter 18 adopts a primary and medium efficiency composite filter group, which can filter solid particles in the exhaust air of the sludge drying line 5 and effectively reduce the corrosion effect of the exhaust gas of the sludge drying line 5 on the anti-corrosion and energy-saving system.

[0043] In summary, the present invention includes a casing and a heat recovery unit, a heating unit and a sludge purification unit arranged in the casing, and the casing is provided with a return air port and an air supply port; the heat recovery unit includes a precooling part and a reheating part, the heating unit includes a first compressor, a first condenser, a first throttle valve and a first evaporator, and the sludge purification unit includes a low-temperature plasma purification component and an activated carbon purification component. The exhaust air of the sludge drying line passes through the return air port, the precooling part, the low-temperature plasma purification component, the first evaporator, the activated carbon adsorber, the reheating part, the first condenser, and the air supply port in sequence, and is sent back to the sludge drying line after dehumidification and temperature increase. The advantages of the anti-corrosion and energy-saving system for sludge drying are that it can recycle the exhaust gas of the sludge drying line, firstly subject the exhaust gas of the sludge drying line to three-stage cooling and dehumidification, then purification through the low-temperature plasma purification component and the activated carbon purification component, and then two-stage temperature increase, so as to provide a dry hot clean air heat source for the sludge drying line, and has good energy-saving effect and anti-corrosion performance.

[0044] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. An anti-corrosion and energy-saving system for sludge drying, characterized in that: include: A casing and a heat recovery unit, a temperature increasing unit and a sludge purification unit arranged in the casing; The housing is provided with an air return port and an air supply port; The heat recovery unit includes a heat recovery heat exchanger, and the heat recovery heat exchanger includes a pre-cooling part and a reheating part; The temperature increasing unit comprises a temperature increasing module, and the temperature increasing module comprises a first compressor, a first condenser, a first throttle valve and a first evaporator connected by a copper tube; The sludge purification unit includes a low-temperature plasma purification component and an activated carbon purification component, the low-temperature plasma purification component includes a low-temperature plasma generator, and the activated carbon purification component includes an activated carbon adsorber; The return air inlet is connected to the air outlet of the sludge drying line, and the air supply outlet is connected to the air inlet of the sludge drying line. The exhaust air of the sludge drying line passes through the return air inlet, the precooling part, the low-temperature plasma purification component, the first evaporator, the activated carbon adsorber, the reheating part, the first condenser, and the air supply outlet in sequence, and is sent back to the sludge drying line after dehumidification and temperature increase. The precooling part, the first evaporator, the reheating part and the first condenser are treated with anti-corrosion. A compressor cavity is provided in the casing, and the compressor cavity is separated from the path of the exhaust air of the sludge drying line.

2. The anti-corrosion and energy-saving system for sludge drying according to claim 1, characterized in that: The activated carbon purification component also includes an activated carbon desorption device.

3. The anti-corrosion and energy-saving system for sludge drying according to claim 2, characterized in that: The activated carbon desorption device includes a second compressor, a second condenser, a second throttle valve and a second evaporator connected by a copper tube. The second evaporator is arranged between the activated carbon adsorber and the reheating part. A bypass air duct is arranged in the casing. A bypass air valve is arranged at the air inlet of the bypass air duct. The second condenser is arranged in the bypass air duct. There are two activated carbon adsorbers, namely a first activated carbon adsorber and a second activated carbon adsorber. A fresh air valve is arranged on the casing. The exhaust air of the sludge drying line passes through the return air port, the precooling part, the low-temperature plasma purification component, the first evaporator, the first activated carbon adsorber in sequence, and is mixed with the fresh air. After passing through the second evaporator, the reheating part and the first condenser, part of the air is sent back to the sludge drying line through the air supply port, and the other part of the air is sent to the second activated carbon adsorber through the second condenser.

4. The anti-corrosion and energy-saving system for sludge drying according to claim 3, characterized in that: A first activated carbon air duct and a second activated carbon air duct are provided in the casing, and a first main air inlet valve, a first main air outlet valve, a first bypass air inlet valve and a first bypass air outlet valve are correspondingly provided on the first activated carbon air duct, and a second main air inlet valve, a second main air outlet valve, a second bypass air inlet valve and a second bypass air outlet valve are correspondingly provided on the second activated carbon air duct. The first activated carbon adsorber is located in the first activated carbon air duct, and the second activated carbon adsorber is located in the second activated carbon air duct. The opening and closing states of the first main air inlet valve, the first main air outlet valve, the second bypass air inlet valve and the second bypass air outlet valve are consistent, and the opening and closing states of the second main air inlet valve, the second main air outlet valve, the first bypass air inlet valve and the first bypass air outlet valve are consistent.

5. The anti-corrosion and energy-saving system for sludge drying according to claim 4, characterized in that: The second evaporator and the second condenser are subjected to anti-corrosion treatment.

6. The anti-corrosion and energy-saving system for sludge drying according to claim 4, characterized in that: The first bypass gas outlet valve and the second bypass gas outlet valve are both connected to the catalytic combustion furnace.

7. The anti-corrosion and energy-saving system for sludge drying according to claim 4, characterized in that: The wind direction of the exhaust air of the sludge drying line passing through the activated carbon adsorber when the exhaust air is subjected to adsorption treatment is opposite to the wind direction of the exhaust air of the sludge drying line passing through the activated carbon adsorber when the exhaust air is subjected to desorption treatment.

8. The anti-corrosion and energy-saving system for sludge drying according to claim 4, characterized in that: An auxiliary heating device is arranged in the bypass air duct.

9. The anti-corrosion and energy-saving system for sludge drying according to claim 1, characterized in that: The heat recovery heat exchanger is a heat pipe type heat recovery device.

10. The anti-corrosion and energy-saving system for sludge drying according to claim 1, characterized in that: An air filter is arranged at the return air port.

Images