Exhaust gas purification and heat recovery device and method

Abstract

The present invention relates to an exhaust gas purification and heat recovery device (A) for sludge treatment, comprising: a housing defining a first space (203) and a second space (202) separated by a horizontal partition (116); the heat source generating assembly (11) is contained in the first space and comprises at least one compression device (112) and at least one first heat exchanger (114); the purification and heat recovery assembly (12) is contained in the second space and comprises a purification and heat exchange box (12c) and a second heat exchanger (124) arranged in the purification and heat exchange box. The purification and heat recovery assembly further comprises a sealing plate (12a) arranged between the second gas inlet (122) and the gas collection device and a cover plate (12b) extending from the upper end of the sealing plate to the second end wall (1d) in the horizontal direction, and the sealing plate vertically extends downwards from the cover plate to the position below the liquid level of the purification and heat exchange box. Therefore, a closed space is formed among the sealing plate, the cover plate, the liquid level and the second end wall.

Description

Technical Field

[0001] The present invention relates to the field of sludge drying, and more specifically, to a waste gas purification and heat recovery device and method. Background Art

[0002] With the continuous development of urbanization, the amount of sewage generated in industrial production and life that needs to be treated is gradually increasing. As a byproduct of sewage treatment, the output of sludge is also increasing. Compared with sewage, sludge treatment is more difficult. At present, sludge drying treatment is a relatively effective sludge treatment method. Sludge drying treatment usually adopts direct thermal drying, and the dried medium is recycled and reused.

[0003] A large amount of waste gas will be released during the sludge thermal drying process. Its composition is complex and diverse, and it is a mixture of various organic and inorganic gases. If it is discharged directly, it will cause serious secondary pollution to the surrounding environment, seriously endanger the human living environment, and cause heat loss.

[0004] Therefore, there are some waste gas treatment methods, such as biological filtration, waste gas absorption tower, dust collector, etc., but it is difficult to achieve effective waste gas treatment and heat recovery. The dried waste gas is discharged after treatment, and the heat carried by the waste gas is not recovered and reused, which increases the energy consumption cost of drying.

[0005] Existing heat recovery equipment for sludge drying usually recovers and reuses the heat of the waste gas after sludge drying by heat exchange. However, the heat recovery efficiency of existing heat recovery equipment is low, and the sludge impurities contained in the waste gas will clog the heat recovery equipment and cause corrosion, affecting the efficiency of heat recovery.

[0006] Therefore, there is a need for an exhaust gas purification and heat recovery device and method that can effectively purify exhaust gas and recover heat during the sludge drying process. Summary of the invention

[0007] In order to solve the above problems, the present invention proposes a waste gas purification and heat recovery device and method for sludge treatment.

[0008] According to one aspect of the present invention, there is provided a waste gas purification and heat recovery device for sludge treatment, comprising:

[0009] A shell, the shell comprising an upper cover, a bottom plate, a horizontal partition, a first side wall, a second side wall opposite to the first side wall, a first end wall and a second end wall opposite to the first end wall, and defining a first space and a second space separated by the horizontal partition, the shell being provided with a first gas inlet and a first gas outlet communicating with the first space, and a second gas inlet communicating with the second space, the first gas inlet being provided on the first end wall, the first gas outlet being provided on the second end wall, the second gas inlet being provided on the second end wall, and the shell being further provided with a second gas outlet;

[0010] a heat source generating assembly accommodated in the first space, the heat source generating assembly comprising at least one compression device and at least one first heat exchanger; and

[0011] a purification and heat recovery assembly accommodated in the second space, the purification and heat recovery assembly comprising a purification and heat exchange box, and a second heat exchanger disposed in the purification and heat exchange box;

[0012] The purification and heat recovery assembly further comprises a sealing plate disposed between the second gas inlet and the gas collecting device, and a cover plate extending horizontally from the upper end of the sealing plate to the second end wall, wherein the sealing plate extends vertically downward from the cover plate to below the liquid level of the purification and heat exchange box, thereby forming a closed space between the sealing plate, the cover plate, the liquid level, and the second end wall.

[0013] The first heat exchange medium circulates between at least one compression device, the first heat exchanger, and the second heat exchanger via a heat exchange medium loop, the first heat exchange medium is compressed in the at least one compression device to form a compressed first heat exchange medium, the compressed first heat exchange medium is introduced into the first heat exchanger, and heat is exchanged with the process gas introduced into the first heat exchanger via the first gas inlet, the process gas is heated to form a heated process gas, and the heated process gas is discharged via the first gas outlet for sludge treatment,

[0014] The waste gas after sludge treatment is introduced into the closed space through the second gas inlet, the waste gas is mixed with the second liquid heat exchange medium in the purification and heat exchange box, the heat is transferred to the second liquid heat exchange medium to be cooled and purified by the second liquid heat exchange medium, the first heat exchange medium flowing through the second heat exchanger exchanges heat with the second liquid heat exchange medium in the purification and heat exchange box, so that the heat of the second liquid heat exchange medium is transferred to the first heat exchange medium flowing through the second heat exchanger.

[0015] According to one example, the heat source generating assembly further comprises at least one ventilation device between the compression device and the first heat exchanger, wherein the ventilation device is used to provide the process gas introduced through the first gas inlet to the first heat exchanger.

[0016] According to one example, the purification and heat recovery component also includes a third heat exchanger and an air collecting device arranged above the liquid level of the purification and heat exchange box, and the air collecting device is arranged above the purification and heat exchange box. The purified exhaust gas of the purification and heat exchange box flows through the third heat exchanger for heat exchange with the first heat exchange medium flowing through the third heat exchanger, and at least a portion of the purified exhaust gas after the heat exchange is guided back to the first heat exchanger through the gas inlet to recycle the treated gas.

[0017] According to one example, the second heat exchanger is arranged in series with the third heat exchanger.

[0018] According to one example, the second heat exchanger is arranged in parallel with the third heat exchanger.

[0019] According to one example, the shell also includes a clear liquid inlet arranged near the bottom of the purification and heat exchange tank and configured to replenish the second liquid heat exchange medium, and a waste liquid outlet arranged near the bottom of the purification and heat exchange tank and configured to discharge the second liquid heat exchange medium; when the second liquid heat exchange medium needs to be replenished, the second liquid heat exchange medium is introduced into the purification and heat exchange tank from the clear liquid inlet; when the purification and heat exchange tank needs to be cleaned, the second liquid heat exchange medium is discharged from the waste liquid outlet.

[0020] According to one example, the shell also includes a compressed gas inlet arranged near the bottom of the purification and heat exchange box, and the purification and heat recovery component also includes a control valve and an injection pipe arranged near the bottom of the purification and heat exchange box and connected to the compressed gas inlet. The control valve is configured to introduce compressed gas into the injection pipe through the compressed gas inlet when necessary, and inject it into the second liquid heat exchange medium of the purification and heat exchange box through a plurality of injection holes arranged on the injection pipe, and then discharge it together with the purified exhaust gas.

[0021] According to an example, the second liquid heat exchange medium is one or more of water, cleaning liquid and ionic liquid.

[0022] According to one example, the purification and heat recovery component also includes an air inlet pipe connected to the second gas inlet, the air inlet pipe extending from the second gas inlet toward the sealing plate and then extending downward to below the liquid level of the purification and heat exchange box, thereby discharging the exhaust gas into the purification and heat exchange box below the liquid level of the purification and heat exchange box.

[0023] According to one example, the process gas is air.

[0024] According to one example, the shell further defines a third space located above the second space, and a secondary purification device is arranged in the third space for performing secondary purification on the purified exhaust gas.

[0025] According to one example, the secondary purification device includes an upper partition net and a lower partition net extending between a first end wall and a second end wall, and a plurality of purification balls retained between the lower partition net and the upper partition net, each purification ball being provided with at least one ball hole for absorbing impurities and moisture in the exhaust gas.

[0026] According to another aspect of the present invention, there is provided a method for purifying and recovering waste gas using the waste gas purification and heat recovery device described above, comprising:

[0027] Introducing the treated gas into the first space through the first gas inlet, exchanging heat with the first heat exchange medium flowing through the first heat exchanger, heating the treated gas to form heated treated gas, and discharging the heated treated gas through the first gas outlet for sludge treatment;

[0028] Introducing the waste gas after sludge treatment into the closed space formed by the sealing plate, the cover plate, the liquid surface and the second end wall through the second gas inlet, the waste gas is mixed with the second liquid heat exchange medium in the purification and heat exchange tank, the heat is transferred to the second liquid heat exchange medium to be cooled and purified by the second liquid heat exchange medium, the first heat exchange medium flowing through the second heat exchanger exchanges heat with the second liquid heat exchange medium in the purification and heat exchange tank, so that the heat of the second liquid heat exchange medium is transferred to the first heat exchange medium flowing through the second heat exchanger; and

[0029] The purified exhaust gas is collected by a gas collecting device for discharge or further purification.

[0030] By forming a closed space together with the sealing plate, the cover plate, the second end wall and the liquid level, the waste gas after sludge drying can enter the liquid through the air inlet pipe, and the waste gas can flow to the vicinity of the second heat exchanger and then be discharged from the liquid surface, thereby extending the residence time of the waste gas in the liquid, achieving sufficient heat exchange with the liquid, and facilitating the collection of the waste gas after primary heat recovery to the gas collecting device, thereby preventing the waste gas from being directly discharged above the liquid level near the air inlet pipe, causing heat loss.

[0031] Other exemplary embodiments of the present invention will become apparent from the detailed description provided hereinafter.It should be understood that the detailed description and specific examples, while disclosing exemplary embodiments of the present invention, are intended for purposes of illustration only and are not intended to limit the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] At least one embodiment will be described below with reference to the following drawings, wherein like reference numerals represent like elements.

[0033] Figure 1 is a perspective view of an exemplary exhaust gas purification and heat recovery device according to the present invention.

[0034] Figure 2is a cross-sectional view of an exemplary exhaust gas purification and heat recovery device according to the present invention.

[0035] Figure 3 4 is a perspective view of a second space of an exemplary exhaust gas purification and heat recovery device according to the present invention.

[0036] Figure 4 4 is a cross-sectional view of a second space of an exemplary exhaust gas purification and heat recovery device according to the present invention.

[0037] Figure 5 It is a cross-sectional view of the second space of another exemplary exhaust gas purification and heat recovery device according to the present invention, showing a sealing plate and a cover plate.

[0038] Figure 6 FIG. 4 is a schematic diagram of a sludge treatment system including an exemplary exhaust gas purification and heat recovery device according to the present invention.

[0039] List of reference numerals:

[0040] A: Exhaust gas purification and heat recovery device;

[0041] B: Blowing device;

[0042] C: Sludge drying device;

[0043] D: Finished product silo device;

[0044] E: Finished product induced draft device;

[0045] F: Bag dust removal device;

[0046] G: induced draft device;

[0047] H: spray tower;

[0048] 1: Shell;

[0049] 1a: first end wall;

[0050] 1b: upper cover;

[0051] 1c: bottom plate;

[0052] 1d: second end wall;

[0053] 2: Load;

[0054] 11: heat source generating component;

[0055] 12: Purification and heat recovery components;

[0056] 12a: sealing plate;

[0057] 12b: Cover plate;

[0058] 12c: Purification and heat exchange box;

[0059] 13: Secondary purification device;

[0060] 116: horizontal partition;

[0061] 111: First gas inlet

[0062] 112: compression device;

[0063] 113: Ventilation device;

[0064] 114: first heat exchanger;

[0065] 115: first gas outlet;

[0066] 120: jet pipe;

[0067] 121: clear liquid inlet;

[0068] 122: second gas inlet;

[0069] 123: air intake pipe;

[0070] 124: second heat exchanger;

[0071] 125: gas collecting device;

[0072] 126: the third heat exchanger;

[0073] 127: Waste liquid outlet;

[0074] 128: turbid liquid outlet;

[0075] 129: compressed gas inlet;

[0076] 131: lower screen;

[0077] 132: Upper separator;

[0078] 133: Purify the sphere;

[0079] 134: ball hole;

[0080] 135: second gas outlet;

[0081] 201: Third Space;

[0082] 202: Second space;

[0083] 203: The first space. DETAILED DESCRIPTION

[0084] The following description is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Figure 1It is a stereoscopic diagram of a preferred embodiment of an exhaust gas purification and heat recovery device A according to the present invention. Figure 2 4 is a cross-sectional view of an exemplary exhaust gas purification and heat recovery device A according to the present invention. Figure 3 2 is a perspective view of a second space 202 of an exemplary exhaust gas purification and heat recovery device A according to the present invention. Figure 4 2 is a cross-sectional view of the second space 202 of an exemplary exhaust gas purification and heat recovery device A according to the present invention. Figure 5 It is a cross-sectional view of the second space 202 of another exemplary exhaust gas purification and heat recovery device A according to the present invention, showing a sealing plate 12a and a cover plate 12b.

[0085] like Figure 1 As shown, the vertical exhaust gas purification and heat recovery device A of the present invention comprises a shell 1, a heat source generating assembly 11 and a purification and heat recovery assembly 12. The shell 1 comprises an upper cover 1b, a bottom plate 1c, a horizontal partition 116, a first side wall (not shown, such as the front wall of the shell), a second side wall opposite to the first side wall (not shown, such as the rear wall of the shell), a first end wall 1a and a second end wall 1d opposite to the first end wall 1a. Figure 1 As shown, the shell 1 is divided into a first space 203, a second space 202 and a third space 201 from bottom to top. The first space 203 and the second space 202 are separated by a horizontal partition 116. It should be understood that the shell 1 can only define the first space 203 and the second space 202 without departing from the scope of the present invention. The upper cover 1b, the bottom plate 1c, the horizontal partition 116, the first side wall, the second side wall, the first end wall 1a and the second end wall 1d can be separate components. It should be understood that one or more of the upper cover 1b, the bottom plate 1c, the horizontal partition 116, the first side wall, the second side wall, the first end wall 1a and the second end wall 1d can also be formed integrally without departing from the scope of the present invention. The shell 1 is provided with a first gas inlet 111 and a first gas outlet 115 communicating with the first space 203, and a second gas inlet 122 communicating with the second space 202. The shell 1 is also provided with a second gas outlet 135.

[0086] The heat source generation assembly 11 is arranged in the first space 203. The heat source generation assembly 11 includes at least one compression device 112 and at least one first heat exchanger 114. The heat source generation assembly also includes at least one ventilation device 113 for accelerating gas delivery between the compression device and the first heat exchanger. It should be understood that the position of the compression device 114 can be changed, that is, the compression device 114 can also be arranged between at least one ventilation device 113 and the first heat exchanger without departing from the scope of the present invention. The first heat exchange medium circulates between at least one compression device 112, the first heat exchanger 114 and the second heat exchanger 124 via a heat exchange medium loop (not shown). For clarity, the various medium pipelines of the heat exchange medium loop are not shown. The heat exchange medium loop can include any suitable device, including pipelines, control valves and check valves. The compression device 112 receives the first heat exchange medium, which is compressed in at least one compression device 112 to form a compressed first heat exchange medium, which is directed to the first heat exchanger 114 to perform heat exchange with the process gas introduced into the first heat exchanger 114 via the first gas inlet 111, and the process gas is heated to form a heated process gas for use in the load 2 (e.g., a sludge drying device). The heated process gas is discharged via the first gas outlet 115 for sludge treatment. According to one example, after heat exchange in the first heat exchanger, the first heat exchange medium becomes a liquid form.

[0087] The heated treated gas is discharged from the first gas outlet 115 and transported to the load 2 through the pipeline to dry the sludge. Since the first heat exchanger transfers the heat of the first heat exchange medium to the treated gas, the treated gas can quickly pass through the sludge to dry the sludge by utilizing the characteristics of fast flow and high energy transfer efficiency of the treated gas, thereby improving the efficiency of sludge drying and facilitating heat recovery. In one example of the present invention, Figure 1 and 2 As shown, the heat source generating assembly includes two compression devices 112 arranged one above the other. However, those skilled in the art should understand that the heat source generating assembly includes any number of compression devices 112, and the compression devices 112 can be arranged in any suitable manner, such as side by side, without departing from the scope of the present invention.

[0088] The purification and heat recovery component 12 is located above the heat source generating component 11 and is contained in the second space 202. The purification and heat recovery component includes a purification and heat exchange box 12c, a second heat exchanger 124 disposed in the purification and heat exchange box, and an air collecting device 125. The air collecting device 125 is disposed above the purification and heat exchange box 12c. The purification and heat exchange box 12c is defined by the horizontal partition 116, the middle part of the first side wall, the middle part of the second side wall, the middle part of the first end wall 1a, and the middle part of the second end wall 1d to accommodate the second liquid heat exchange medium for heat recovery. It should be understood that the purification and heat exchange box 12c can also be a separate box placed on the horizontal partition 116 without departing from the scope of the present invention.

[0089] According to one example, the housing further comprises a clear liquid inlet 121 disposed near the bottom of the purification and heat exchange tank and configured to replenish the second liquid heat exchange medium, and a waste liquid outlet 127 disposed near the bottom of the purification and heat exchange tank and configured to discharge the second liquid heat exchange medium. When the second liquid heat exchange medium needs to be replenished, the second liquid heat exchange medium is introduced into the purification and heat exchange tank from the clear liquid inlet. When the purification and heat exchange tank needs to be cleaned, the second liquid heat exchange medium is discharged from the waste liquid outlet.

[0090] According to one example, the purification and heat recovery component also includes an air intake pipe 123 connected to the second gas inlet 122, and the air intake pipe 123 extends from the second gas inlet 122 toward the sealing plate 12a and then extends downward to below the liquid level of the purification and heat exchange box, thereby discharging the exhaust gas into the purification and heat exchange box 12c below the liquid level of the purification and heat exchange box.

[0091] According to one example, the housing 1 further includes a compressed gas inlet 129 disposed near the bottom of the purification and heat exchange box 12c, and the purification and heat recovery assembly further includes a control valve (not shown) and an injection pipe 120 disposed near the bottom of the purification and heat exchange box 12c and communicating with the compressed gas inlet 129. The control valve is configured to introduce the compressed gas into the injection pipe 120 via the compressed gas inlet 129 when necessary, and inject it into the second liquid heat exchange medium of the purification and heat exchange box 12c through a plurality of injection holes disposed on the injection pipe 120, and then discharge it together with the purified exhaust gas.

[0092] The purification and heat recovery assembly 12 further includes a third heat exchanger 126 disposed above the liquid level of the purification and heat exchange tank. The purified exhaust gas of the purification and heat exchange tank flows through the third heat exchanger for heat exchange with the first heat exchange medium flowing through the third heat exchanger 126, and at least a portion of the purified exhaust gas after heat exchange is guided back to the first heat exchanger through the gas inlet to recycle the treated gas.

[0093] The gas collecting device 125 has a gas inlet for collecting the primary heat recovery waste gas and a gas outlet for discharging the waste gas to be recovered for secondary heat. The gas inlet of the gas collecting device corresponds to the liquid level so as to collect the primary heat recovery waste gas. The gas outlet of the gas collecting device corresponds to at least one third heat exchanger 126 so as to transport the collected primary heat recovery waste gas to at least one third heat exchanger 126 for secondary heat recovery. At least one third heat exchanger 126 is arranged near the turbid liquid outlet 128 and above at least one second heat exchanger 124. The gas collecting device and at least one third heat exchanger are both arranged above the liquid surface. In addition, one end of the jet pipe 120 is connected to the compressed gas inlet 129, and the other end of the pipeline extends horizontally to the inside of the purification and heat recovery component and at least one jet hole is provided on the jet pipe. The waste gas after sludge drying is transported to the outlet of the inlet pipe through the curved path of the inlet pipe for primary heat recovery with the liquid, and the heat in the waste gas is transferred to the liquid. The second liquid heat exchange medium carrying the heat then transfers the heat to at least one second heat exchanger to achieve heat exchange. After the exhaust gas undergoes primary heat recovery, it leaves the liquid and is collected in the gas collecting device. The collected exhaust gas is discharged through the outlet of the gas collecting device and transported to at least one third heat exchanger for secondary heat recovery to achieve heat exchange. Subsequently, the purified and heat-recovered gas is discharged from the outlet of the purification and heat recovery component.

[0094] The first heat exchange medium is connected in the first heat exchanger, the second heat exchanger and the third heat exchanger through a medium pipeline (not shown), and the heat recovered by the second heat exchanger and the third heat exchanger is transferred to the first heat exchanger through the first heat exchange medium to achieve heat recovery. Through the primary heat recovery of the waste gas and the liquid, the sludge impurities in the waste gas are cleaned and the heat is transferred to the liquid at the same time. The liquid then exchanges heat with the second heat exchanger, which can prevent the sludge impurities in the waste gas from corroding the second heat exchanger and improve the efficiency of heat recovery. In addition, the waste gas that has undergone primary heat recovery is heat exchanged with the third heat exchanger again to achieve full heat recovery, and then the heat is transferred to the first heat exchanger through the first heat exchange medium, thereby improving the heat supply efficiency of the first heat exchanger. In another embodiment, the purification and heat recovery component 12 may not be equipped with the gas collecting device 125, and at least one third heat exchanger 126 is arranged near the turbid liquid outlet 128 and above the at least one second heat exchanger 124. At least one third heat exchanger is arranged above the liquid surface. After the exhaust gas undergoes primary heat recovery, it rises freely after leaving the liquid and is transported to at least one third heat exchanger for secondary heat recovery to achieve heat exchange.

[0095] At least one air inlet pipe 123 may include multiple air inlet pipes extending downward and having multiple gas outlets extending below the liquid surface, so that more waste gas after sludge drying enters below the liquid surface, increasing the contact frequency between the waste gas and the liquid and improving the heat exchange efficiency.

[0096] The second liquid heat exchange medium is water, but the second liquid heat exchange medium is not limited to water, and other suitable second liquid heat exchange mediums may also be used, such as cleaning liquid, ionic liquid, etc.

[0097] In another embodiment, a sealing plate 12a is provided in the vertical direction between the air inlet pipe and the air collecting device of the purification and heat recovery component, and the sealing plate is fixedly connected to the first side wall and the second side wall. The upper part of the sealing plate extends to the cover plate 12b, and the lower part of the sealing plate extends below the liquid level, wherein the sealing plate, the cover plate, the second end wall 1d and the liquid level together form a closed space, which can allow the waste gas after sludge drying to enter the liquid through the air inlet pipe, and the waste gas can flow to the vicinity of the second heat exchanger and then be discharged from the liquid surface, thereby extending the residence time of the waste gas in the liquid and realizing sufficient heat exchange with the liquid, and facilitating the collection of the waste gas after primary heat recovery to the air collecting device, thereby preventing the waste gas from being directly discharged above the liquid level near the air inlet pipe, causing heat loss.

[0098] The secondary purification device 13 is disposed in the third space 201, above the purification and heat recovery assembly 12. It includes an upper partition 132 and a lower partition 131 extending between the first end wall 1a and the second end wall 1d, and a plurality of purification balls 133 retained between the lower partition and the upper partition, each of which is provided with at least one ball hole 134 for absorbing impurities and moisture in the exhaust gas. When the exhaust gas after secondary heat recovery rises to the secondary purification device 13, the exhaust gas passes through the ball holes 134 between the plurality of purification balls 133 or the plurality of purification balls, and the purification balls absorb impurities and moisture in the exhaust gas to convert the exhaust gas into secondary purified gas, which is discharged from the second gas outlet 135. According to one example, the second gas outlet 135 is located in the upper cover 1b of the shell 1, as shown in FIG. Figure 1 However, it should be understood that the second gas outlet 135 is located at any other suitable position of the shell 1, such as in the first side wall, the second side wall, the first end wall 1a or the second end wall 1d of the shell 1, without departing from the scope of the present invention. According to one example, the secondary purified gas is transported to the first gas inlet 111 of the heat source generating assembly 11 through a pipeline to achieve gas recycling.

[0099] According to an example of the present invention, for the flow path of the first heat exchange medium, the second heat exchanger 124 is arranged in series downstream of the third heat exchanger 126 (relative to the flow direction of the first heat exchange medium). However, the second heat exchanger 124 can also be arranged in series upstream of the third heat exchanger 126. In addition, the second heat exchanger 124 can also be arranged in parallel with the third heat exchanger 126, and a part of it can be below the liquid surface and the other part can be above the liquid surface.

[0100] The compression device 112 compresses the first heat exchange medium in a gaseous state, and delivers the compressed high-temperature and high-pressure first heat exchange medium to the first heat exchanger 114. The first heat exchange medium is condensed in the first heat exchanger 114 by the process gas (such as air from the outside) flowing through the first heat exchanger 114, and becomes liquid, thereby heating the process gas.

[0101] According to one embodiment of the present invention, the first heat exchange medium after heat exchange in the first heat exchanger 114 enters the second heat exchanger 124 and / or the third heat exchanger 126 in a low-temperature and low-pressure liquid form through corresponding pipelines and control valves (not shown). According to one embodiment of the present invention, in the second heat exchanger 124 and / or the third heat exchanger 126, the first heat exchange medium absorbs heat to evaporate, and the evaporated first heat exchange medium is sucked into the compression device 112 to perform a new compression cycle. According to another embodiment of the present invention, in the second heat exchanger 124 and / or the third heat exchanger 126, the first heat exchange medium absorbs heat but is still in liquid form, and the first heat exchange medium in liquid form is sucked into the compression device 112 to perform a new compression cycle. The first heat exchange medium can be, for example, R134a, R407c, R410a, etc. It should be understood by those skilled in the art that the first heat exchanger 114, the second heat exchanger 124 and the third heat exchanger 126 can be any other suitable type of heat exchanger without departing from the scope of the present invention.

[0102] According to a preferred embodiment of the present invention, the process gas first flows outside the compression device 112 before flowing through the first heat exchanger 114, which helps cool the compression device 112 and is thus preheated, thereby improving the heat recovery efficiency.

[0103] In one embodiment of the present invention, load 2 is disposed downstream of the first heat exchanger 114, and is used to process the sludge and discharge the waste gas. A large amount of waste gas will be released during the sludge thermal drying process, and its composition is complex and diverse, and it is a mixture of various organic and inorganic gases. If it is directly discharged, it will cause serious secondary pollution to the surrounding environment and cause serious harm to the human living environment. In addition, since there is waste heat in the waste gas, direct discharge will cause heat loss. In one embodiment of the present invention, load 2 is a sludge drying device. It should be understood by those skilled in the art that load 2 can also be any other suitable type of sludge treatment device without departing from the scope of the present invention.

[0104] A plurality of second heat exchangers 124 may be provided inside the purification and heat exchange box 12c as required, and the plurality of second heat exchangers 124 may be arranged in series or in parallel, thereby improving the efficiency of transferring the heat of the second liquid heat exchange medium to the first heat exchange medium. The exhaust gas entering the purification and heat recovery device A is purified and heat recovered in a closed environment, preventing the generation of odor, eliminating secondary pollution, and being very environmentally friendly.

[0105] In one embodiment of the present invention, the second liquid heat exchange medium is water. However, the second liquid heat exchange medium is not limited to water, and other suitable liquids may also be used, such as cleaning liquid, ionic liquid, etc.

[0106] The secondary purified gas still carries a portion of heat, which can be circulated to the first gas inlet 111 for reuse, and further heat recovery is achieved. According to an example of the present invention, the secondary purified gas is guided back to the first space 203 through the first gas inlet 111 to recycle the process gas. Of course, as needed, the secondary purified gas can be discharged only to the environment or other processing devices (not shown) through the second gas outlet; alternatively, a portion of the secondary purified gas is guided back to the first heat exchanger 114 through the first gas inlet 111 to recycle the process gas, while another portion of the secondary purified gas is discharged via the second gas outlet. Any suitable device may be included, including a pipeline, a control valve, and a check valve.

[0107] The waste gas is cleaned in the purification and heat exchange box 12c and transfers heat to the second liquid heat exchange medium, thereby being cooled. This achieves the purification of the waste gas and the recovery of heat. After cooling, the waste gas automatically rises above the liquid level of the second liquid heat exchange medium in the second liquid heat exchange medium and is then collected by the gas collection device 125.

[0108] The second liquid heat exchange medium that obtains heat from the exhaust gas transfers the heat to the first heat exchange medium flowing in the second heat exchanger 124 via the second heat exchanger 124 to evaporate the first heat exchange medium.

[0109] The exhaust gas purification and heat recovery device according to the present invention also includes an air collecting device 125, which is arranged above the purification and heat exchange box 12c and is used to collect the exhaust gas that has been heat exchanged and cleaned from the purification and heat exchange box 12c. The exhaust gas transfers heat to the second liquid heat exchange medium in the purification and heat exchange box 12c to be cooled, thereby realizing heat recovery. After cooling, the exhaust gas automatically rises above the liquid level of the second liquid heat exchange medium in the second liquid heat exchange medium, and is then collected by the air collecting device 125. The exhaust gas that has been heat exchanged and cleaned collected by the air collecting device 125 flows through the third heat exchanger 126, and is used to exchange heat with the first heat exchange medium flowing through the third heat exchanger 126. Of course, multiple third heat exchangers 126 can be set above the purification and heat exchange box 12c as needed. The multiple third heat exchangers 126 can be arranged in series or in parallel. The exhaust gas that has been heat exchanged and cleaned and collected by the gas collecting device 125 flows through the first heat exchange medium of the multiple heat exchangers for heat exchange, thereby improving the efficiency of the heat exchange.

[0110] The first heat exchange medium flowing through the second heat exchanger 124 and / or the third heat exchanger 126 is heated and vaporized, and is directed back to the first heat exchanger 114 to repeat the cycle process.

[0111] In one embodiment of the present invention, the secondary purification device 13 is arranged above the third heat exchanger 126. The secondary purification device 13 is used to perform secondary purification on the waste gas that has been heat exchanged and cleaned after heat exchange to produce secondary purified gas. In one embodiment of the present invention, the secondary purified gas is guided back to the compression device 112 or the first heat exchanger 114. The secondary purified gas treated by the secondary purification device 13 still carries a part of the heat, which can be circulated to the first gas inlet 111 for reuse, and further heat recovery is achieved. Of course, according to needs, the secondary purified gas can be discharged only from the gas outlet to the environment or other processing devices; or part of the secondary purified gas is guided back to the first heat exchanger 114 through the gas inlet to recycle the secondary treated gas, and the other part is discharged from the gas outlet.

[0112] The secondary purified gas may also be discharged to the environment via the gas outlet. The secondary purification device 13 and the purification device 129 may also include a wire mesh demister, a packing demister, etc. In addition, multiple secondary purification devices may be provided as required.

[0113] Optionally, an additional heat exchanger (not shown) may be provided through which the first heat exchange medium flows so as to transfer heat in the turbid liquid flowing out of the purification and heat exchange tank 12c to the first heat exchange medium, further improving the heat recovery efficiency.

[0114] According to a preferred embodiment of the present invention, the purification and heat exchange tank 12c includes a clean liquid inlet 121 and a waste liquid outlet 128 disposed near the bottom of the purification and heat exchange tank 12c.

[0115] Since the waste gas contains sludge impurities, during the gas-liquid interaction in the purification and heat exchange box 12c, the sludge impurities in the waste gas are cleaned by the spraying liquid and mixed with the second liquid heat exchange medium, and retained in the second liquid heat exchange medium. In order to keep the second liquid heat exchange medium clean and ensure the efficiency of heat exchange, the second liquid heat exchange medium (such as water) is introduced into the purification and heat exchange box 12c from the clear liquid inlet 121 at the bottom of the purification and heat exchange box 12c.

[0116] As the sludge impurities in the liquid continue to increase, the second liquid heat exchange medium in the purification and heat exchange tank 12c becomes turbid, which in turn affects the heat exchange and cleaning of the waste gas entering later, and some devices also need to be repaired or replaced. For this reason, the water intake can be stopped, and the liquid can be discharged from the waste liquid outlet 128 at the bottom of the purification and heat exchange tank 12c. Afterwards, the reverse operation is performed to refill water into the purification and heat exchange tank 12c.

[0117] If too much sludge impurities accumulate at the bottom of the purification and heat exchange box 12c, affecting the heat exchange efficiency of the second heat exchanger 124, the compressed gas is transported from the compressed gas inlet 129 to the jet pipe arranged near the bottom of the purification and heat exchange box 12c. After that, the compressed gas is ejected through the multiple jet holes arranged on the jet pipe, and the sludge impurities at the bottom of the purification and heat exchange box 12c are stirred up to help the sludge impurities be discharged from the waste liquid outlet 128. The compressed gas leaving the second liquid heat exchange medium is automatically raised to the third compartment, and is discharged from the second gas outlet 125 together with the secondary purified gas, or is guided back to the compression device 112.

[0118] According to a preferred embodiment of the present invention, the second heat exchanger 124 is directly placed in the purification and heat exchange box 12c, thereby achieving sufficient heat exchange.

[0119] According to a preferred embodiment of the present invention, the process gas is air. However, the process gas may also be any other gas suitable for the present invention.

[0120] According to a preferred embodiment of the present invention, the treated gas is sent to the sludge treatment device from the first heat exchanger 114 by a ventilation device (not shown). The ventilation device is preferably a blower device B and / or an induced draft device.

[0121] Figure 5Schematic diagram of a sludge treatment system including an exemplary exhaust gas purification and heat recovery device A according to the present invention. According to one example, the sludge treatment system includes an exhaust gas purification and heat recovery device A, a blast device B, a sludge drying device C, a finished product silo device D, a finished product induced draft device E, a bag dust removal device F and an induced draft device G. The sludge treatment system may also include a spray tower H in fluid communication with the second gas outlet 135 of the exhaust gas purification and heat recovery device A. The finished sludge after drying by the sludge drying device C enters the finished product silo device D, and then is discharged and loaded. The exhaust gas generated by the sludge drying device C after drying will be collected in the bag dust removal device F for the first step of dust reduction and deodorization treatment. At the same time, the dust exhaust gas generated by the finished product silo device D is also guided to the bag dust removal device F for treatment via the finished product induced draft device E. The gas treated by the bag dust removal device F is brought to the self-cleaning heat recovery device or the exhaust gas purification and heat recovery device A by the induced draft device G, and the exhaust gas is recovered by the exhaust gas purification and heat recovery device A, and secondary purification is performed to produce secondary purified gas. The secondary purified gas is heated by the first heat exchange medium to produce heated treated gas. The heated treated gas is then provided to the sludge drying device C by the blower device B to dry the sludge. From here, we can see the hot air circulation direction of the entire sludge treatment system, and we can also see the importance of heat recovery and dust removal. Although the exhaust gas introduced from the induced draft device G to the exhaust gas purification and heat recovery device A has been treated by the bag dust removal device F, it is inevitable that a small amount of dust will enter the exhaust gas purification and heat recovery device A along with the water vapor and exhaust gas, and the exhaust gas has residual heat. In addition, part of the secondary purified gas from the exhaust gas purification and heat recovery device A can be discharged to the spray tower H for another dust removal and heat recovery, and then guided to the biological deodorization device through the spray tower H for terminal treatment and then discharged to the outside, or directly discharged to the outside after being treated by the spray tower H and meeting the standards.

[0122] Next, refer to Figure 1 and 2 The operation of the exhaust gas purification and heat recovery device of the present invention is described.

[0123] First, the liquid inlet of the purification and heat recovery assembly is opened by a control valve, and liquid is injected into the purification and heat exchange tank 12c from the liquid inlet. Under normal circumstances, the liquid will reach a predetermined liquid level in the purification and heat exchange tank 12c.

[0124] The treated gas is introduced into the first space 203 through the first gas inlet 111. The treated gas first flows through the compression device and then flows to the first heat exchanger 114. The first heat exchanger heats the gas to form heated treated gas. The heated treated gas is sent to the load 2 through the first gas outlet 115 by the ventilation device (such as a blower and / or an induced draft fan) to dry the sludge and generate waste gas with sludge impurities.

[0125] The waste gas after sludge treatment is introduced into the purification and heat recovery component through the second gas inlet 122. The waste gas is discharged into the second liquid heat exchange medium in the purification and heat recovery component through the air inlet pipe 123, so as to transfer the heat in the waste gas to the liquid, realize gas-liquid heat exchange, and thus realize heat recovery of the heat in the waste gas. In this heat exchange process, the waste gas temperature is lowered and purified once, and automatically flows upward to above the liquid level, and then is collected by the gas collection device. The collected waste gas is transported to the third heat exchanger for secondary heat recovery to fully recover the heat of the waste gas. When the waste gas after secondary heat recovery rises to the secondary purification device, the waste gas flows through multiple purification spheres or multiple ball holes of purification spheres. The purification spheres absorb impurities and moisture in the waste gas to turn the waste gas into secondary purified gas, which is discharged from the gas outlet. The secondary purified gas is transported to the gas inlet of the heat source generating component through a pipeline to realize gas recycling.

[0126] At the same time, the compression device compresses the first heat exchange medium and discharges the compressed first heat exchange medium into the first heat exchanger. In the first heat exchanger, the first heat exchange medium releases heat to the gas flowing through the first heat exchanger to achieve heat exchange between the first heat exchange medium and the treated gas. Then, the condensed first heat exchange medium flows to the second heat exchanger and the third heat exchanger. As pointed out above, the first heat exchange medium in the purification and heat recovery assembly absorbs the heat in the exhaust gas, causing its temperature to rise. Therefore, the first heat exchange medium can absorb the heat in the exhaust gas and evaporate in the second heat exchanger, thereby reducing the temperature of the first heat exchange medium, so that it can continue to absorb the heat of the exhaust gas discharged therein. By converting the heat of the exhaust gas to the first heat exchange medium, and then transferring the heat energy to the treated gas by the first heat exchanger, multi-phase heat energy conversion is achieved, which greatly improves the transfer efficiency of heat energy. Through the heat conversion of the exhaust gas and the first heat exchange medium, heat can be fully recovered, heat loss can be reduced, and energy consumption can be reduced.

[0127] Since the waste gas carries some sludge impurities, when the purification and heat recovery component recovers the waste gas, the sludge impurities at the bottom accumulate too much, affecting the heat exchange efficiency of the second heat exchanger. The compressed gas can be transported from the compressed gas inlet to the jet pipe near the bottom of the purification and heat recovery component. After that, the compressed gas is ejected through the multiple jet holes set on the air pipe, and the sludge impurities at the bottom of the purification and heat recovery component are stirred up to help the sludge impurities be discharged from the waste liquid outlet 128.

[0128] As the sludge impurities in the liquid continue to increase, the second liquid heat exchange medium in the purification and heat recovery component becomes turbid, which in turn affects the heat exchange and cleaning of the waste gas entering later, and some devices also need to be repaired or replaced. Open the control valve to discharge the liquid from the waste liquid outlet of the purification and heat recovery component, and then perform the reverse operation to re-input liquid into the second liquid heat exchange medium inlet of the purification and heat recovery component.

[0129] The present invention has described certain preferred embodiments and variations thereof. Other variations and changes may occur to those skilled in the art after reading and understanding the specification. Thus, the present invention is not limited to the specific embodiments disclosed as the best mode for carrying out the present invention, and the present invention will include all embodiments falling within the scope of the claims.

Claims

1. A waste gas purification and heat recovery device for sludge treatment (A), comprising: A shell (1), the shell (1) comprising an upper cover (1b), a bottom plate (1c), a horizontal partition (116), a first side wall, a second side wall opposite to the first side wall, a first end wall (1a) and a second end wall (1d) opposite to the first end wall (1a), and defining a first space (203) and a second space (202) separated by the horizontal partition (116); the shell (1) is provided with a first gas inlet (111) and a first gas outlet (115) communicating with the first space (203), and a second gas inlet (122) communicating with the second space (202); the shell (1) is also provided with a second gas outlet (135); a heat source generating assembly (11) accommodated in the first space, the heat source generating assembly (11) comprising at least one compression device (112) and at least one first heat exchanger (114); and a purification and heat recovery component (12) accommodated in the second space, the purification and heat recovery component comprising a purification and heat exchange box (12c), and a second heat exchanger (124) arranged in the purification and heat exchange box; The purification and heat recovery assembly further comprises a sealing plate (12a) arranged between the second gas inlet (122) and the gas collecting device, and a cover plate (12b) extending horizontally from the upper end of the sealing plate to the second end wall (1d), wherein the sealing plate extends vertically downward from the cover plate to below the liquid level of the purification and heat exchange box, thereby forming a closed space between the sealing plate, the cover plate, the liquid level, and the second end wall (1d). The first heat exchange medium circulates between at least one compression device (112), a first heat exchanger (114) and a second heat exchanger (124) via a heat exchange medium loop. The first heat exchange medium is compressed in the at least one compression device (112) to form a compressed first heat exchange medium. The compressed first heat exchange medium is introduced into the first heat exchanger (114) to perform heat exchange with the process gas introduced into the first heat exchanger (114) via the first gas inlet (111). The process gas is heated to form a heated process gas. The heated process gas is discharged via the first gas outlet (115) for sludge treatment. The waste gas after sludge treatment is introduced into the closed space through the second gas inlet (122), and the waste gas is mixed with the second liquid heat exchange medium in the purification and heat exchange box (12c), and the heat is transferred to the second liquid heat exchange medium to be cooled and purified by the second liquid heat exchange medium. The first heat exchange medium flowing through the second heat exchanger exchanges heat with the second liquid heat exchange medium in the purification and heat exchange box, so that the heat of the second liquid heat exchange medium is transferred to the first heat exchange medium flowing through the second heat exchanger.

2. The exhaust gas purification and heat recovery device (A) according to claim 1, wherein: The heat source generating assembly further comprises at least one ventilation device (113) between the compression device and the first heat exchanger, wherein the ventilation device is used to provide the processing gas introduced through the first gas inlet to the first heat exchanger.

3. The exhaust gas purification and heat recovery device (A) according to claim 1, wherein: The purification and heat recovery component also includes a third heat exchanger (126) and an air collecting device (125) arranged above the liquid level of the purification and heat exchange box. The air collecting device (125) is arranged above the purification and heat exchange box. The purified exhaust gas of the purification and heat exchange box flows through the third heat exchanger to exchange heat with the first heat exchange medium flowing through the third heat exchanger, and at least a part of the purified exhaust gas after the heat exchange is guided back to the first heat exchanger through the gas inlet to recycle the treated gas.

4. The exhaust gas purification and heat recovery device (A) according to claim 3, wherein: The second heat exchanger is arranged in series with the third heat exchanger.

5. The exhaust gas purification and heat recovery device (A) according to claim 3, wherein: The second heat exchanger is arranged in parallel with the third heat exchanger.

6. The exhaust gas purification and heat recovery device (A) according to claim 1, wherein: The shell also includes a clean liquid inlet (121) arranged near the bottom of the purification and heat exchange box and configured to supply a second liquid heat exchange medium, and a waste liquid outlet (127) arranged near the bottom of the purification and heat exchange box and configured to discharge the second liquid heat exchange medium; when the second liquid heat exchange medium needs to be replenished, the second liquid heat exchange medium is introduced into the purification and heat exchange box from the clean liquid inlet; when the purification and heat exchange box needs to be cleaned, the second liquid heat exchange medium is discharged from the waste liquid outlet.

7. The exhaust gas purification and heat recovery device (A) according to claim 6, wherein: The shell also includes a compressed gas inlet (129) arranged near the bottom of the purification and heat exchange box, and the purification and heat recovery component also includes a control valve and an injection pipe (120) arranged near the bottom of the purification and heat exchange box and connected to the compressed gas inlet (129). The control valve is configured to introduce compressed gas into the injection pipe through the compressed gas inlet when needed, and inject it into the second liquid heat exchange medium of the purification and heat exchange box through a plurality of injection holes arranged on the injection pipe, and then discharge it together with the purified exhaust gas.

8. The exhaust gas purification and heat recovery device (A) according to claim 1, wherein: The second liquid heat exchange medium is one or more of water, cleaning liquid and ionic liquid.

9. The exhaust gas purification and heat recovery device (A) according to claim 1, wherein: The purification and heat recovery component also includes an air inlet pipe (123) connected to the second gas inlet (122), and the air inlet pipe (123) extends from the second gas inlet (122) toward the sealing plate (12a) and then extends downward to below the liquid level of the purification and heat exchange box, thereby discharging the exhaust gas into the purification and heat exchange box below the liquid level of the purification and heat exchange box.

10. The exhaust gas purification and heat recovery device (A) according to claim 1, wherein: The process gas is air.

11. The exhaust gas purification and heat recovery device (A) according to claim 1, wherein: The first gas inlet (111) is arranged on the first end wall (1a), the first gas outlet (115) is arranged on the second end wall (1d), and the second gas inlet (122) is arranged on the second end wall (1d). The shell further defines a third space (201) located above the second space. The second gas outlet (135) is arranged to communicate with the third space (201). The secondary purification device (13) is arranged in the third space for performing secondary purification on the purified exhaust gas.

12. The exhaust gas purification and heat recovery device (A) according to claim 11, wherein: The secondary purification device comprises an upper partition net (132) and a lower partition net (131) extending between a first end wall (1a) and a second end wall (1d), and a plurality of purification balls (133) held between the lower partition net and the upper partition net, each purification ball being provided with at least one ball hole (134) for absorbing impurities and moisture in the exhaust gas.

13. A method for purifying and recovering waste gas using the waste gas purification and heat recovery device according to any one of claims 1 to 12, comprising: Introducing the treated gas into the first space through the first gas inlet (111), exchanging heat with the first heat exchange medium flowing through the first heat exchanger, heating the treated gas to form heated treated gas, and discharging the heated treated gas through the first gas outlet (115) for sludge treatment; The waste gas after sludge treatment is introduced into the closed space formed between the sealing plate, the cover plate, the liquid surface and the second end wall (1d) through the second gas inlet (122), the waste gas is mixed with the second liquid heat exchange medium in the purification and heat exchange box (12c), the heat is transferred to the second liquid heat exchange medium to be cooled and purified by the second liquid heat exchange medium, the first heat exchange medium flowing through the second heat exchanger exchanges heat with the second liquid heat exchange medium in the purification and heat exchange box, so that the heat of the second liquid heat exchange medium is transferred to the first heat exchange medium flowing through the second heat exchanger; and The purified waste gas is collected by the gas collecting device (125) to be discharged or further purified.

14. A sludge treatment system comprising: The exhaust gas purification and heat recovery device (A) according to any one of claims 1 to 12; A blast device (B) disposed downstream of the exhaust gas purification and heat recovery device (A); a sludge drying device (C) disposed downstream of the air blowing device (B), the air blowing device (B) being configured to guide the secondary purified gas purified by the exhaust gas purification and heat recovery device (A) to the sludge drying device (C); a dust removal device (F) disposed downstream of the sludge drying device (C); and The induced draft device (G) is arranged downstream of the dust removal device (F), and the induced draft device (G) is configured to guide the exhaust gas processed by the dust removal device (F) to the exhaust gas purification and heat recovery device (A).

15. The sludge treatment system according to claim 14 further comprises a spray tower (H) fluidly connected to the second gas outlet (135) of the exhaust gas purification and heat recovery device (A), and a portion of the secondary purified gas from the exhaust gas purification and heat recovery device (A) is transported to the spray tower (H) for further purification and heat recovery.

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