Biogas residue drying treatment equipment

Abstract

The invention discloses biogas residue drying treatment equipment, and belongs to the technical field of drying equipment, the biogas residue drying treatment equipment comprises a main body, the main body comprises a feeding section, a working section and a discharging section, and skins are arranged on the outer sides of the feeding section, the working section and the discharging section; the drying belt is arranged in the main body in a penetrating and coiling manner, the drying belt is provided with meshes, and the internal space of the main body is vertically divided into a contact area and an air return area by the drying belt. Through the arrangement of the main body, the drying belt, the feeder, the negative pressure fan and the air heat exchanger, biogas residues with different humidity are spread to the drying belt by the feeder in different thicknesses, the drying adaptability of the equipment is improved on the premise of ensuring the consistency of the discharging humidity, the air inlet path is optimized through the air heat exchanger, and the drying efficiency is improved. Therefore, hot air is blown to one side, far away from the negative pressure fan, of the drying belt and then is sucked forwards by negative pressure of the negative pressure fan, and hot air coverage of the whole drying belt is completed in a short path.

Description

Technical Field

[0001] The present invention belongs to the technical field of drying equipment, and particularly relates to a marsh gas residue drying and processing device. Background Art

[0002] The marsh gas residue drying and processing device is applicable to the drying of wet marsh gas residues after solid-liquid separation in biogas projects, wet sludge in sewage treatment systems, and waste such as chicken manure and cow manure. In the specific processing scenario of using a belt-type marsh gas residue drying device, a heat source needs to be connected to evaporate water vapor.

[0003] The existing Chinese utility model patent with the publication number CN204313616U discloses a marsh gas residue dryer that uses a mesh belt to drive the marsh gas residue above the heat source. However, in actual use, the design of multiple mesh belts results in a lower hot air temperature and higher humidity at the upper mesh belt position, causing the hot air temperature that the marsh gas residue in the upper mesh belt can contact to be lower, and even the phenomenon of secondary condensation of water vapor in the upward airflow in the upper low-temperature marsh gas residue. This multi-layer distribution of the mesh belt leads to poor drying consistency of the marsh gas residue and also significantly increases the drying time. In view of this, a marsh gas residue drying and processing device is provided to solve the above problems. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned disadvantages of the prior art and provide a marsh gas residue drying and processing device.

[0005] The technical solution adopted to solve the above technical problem is as follows: A marsh gas residue drying and processing device includes: A main body, the main body includes a feeding section, a working section, and a discharging section, the feeding section, the working section, and the discharging section are arranged in sequence end to end, and a skin is provided on the outer sides of the feeding section, the working section, and the discharging section; A drying belt, the drying belt is wound through and arranged in the main body, the drying belt has mesh holes, and the drying belt divides the internal space of the main body into an upper contact area and a lower return air area; A feeder, the feeder is installed on the feeding section in a liftable manner, and the feeder spreads marsh gas residues with different thicknesses on the upper surface of the drying belt; A negative pressure fan, the negative pressure fan is fixed on the vertical side wall of the working section, and the negative pressure fan continuously extracts air from the contact area and the return air area; An air heat exchanger, the air heat exchanger has a thin-walled plate filled with hot water, an outer shell is sleeved outside the thin-walled plate, the outer shell is communicated with the contact area, fins are provided on the outer wall of the thin-walled plate, and the lower ends of the fins are inclined away from the negative pressure fan so that the incoming air is attracted by the negative pressure fan and crosses the drying belt.

[0006] Further, the working section includes a carrier frame, which is fixed to the bottom surface of the working section. The carrier frame is arranged below a part of the drying belt located inside the working section, and the carrier frame is in sliding contact with the drying belt.

[0007] Through the above technical solution, to ensure that the drying belt passes horizontally, the carrier frame supports a part of the drying belt located inside the working section, ensuring the flatness of the drying belt, and thus ensuring the controllability of the thickness of the feed.

[0008] Further, a lifting structure is provided at the lower part of the feeder. The lifting structure is fixedly connected to the top surface of the feeding section. A distributor is provided at the outlet of the feeder. The distributor has a plurality of outlets. A flattening member is provided at the outlet of the distributor. A material passing space is left between the bottom surface of the flattening member and the top surface of the drying belt.

[0009] Through the above technical solution, to adapt to biogas residues with different humidities, when the biogas residues are relatively wet, the lifting structure lowers the height of the feeder, reducing the material passing space between the bottom surface of the flattening member and the top surface of the drying belt, reducing the thickness of the biogas residues, and dispersing the feed through the distributor and flattening it through the flattening member to prevent incomplete drying caused by uneven stacking during drying. When the biogas residues are relatively dry, the height of the feeder can be increased to increase the amount of biogas residues entering per unit time and improve the drying efficiency.

[0010] Further, support rollers are provided on the upper part of the carrier frame. The support rollers are in rolling contact with the lower surface of a part of the drying belt located inside the working section. Support hairs are installed on the circumferential side wall of the support rollers along the tangential direction. The support hairs can be inserted into and pulled out of the mesh holes from bottom to top when the support rollers rotate.

[0011] Through the above technical solution, to improve the dehydration speed of the biogas residues on the drying belt, the support rollers lift the drying belt and provide rolling support, reducing wear. The support hairs can be inserted into the mesh holes to lift the biogas residues above the drying belt, making the biogas residues fluffy to prevent caking and keeping the mesh holes unblocked, so that hot air can pass through the stacked biogas residues more smoothly and evenly.

[0012] Further, the working section includes a keel. A top frame connected to an air heat exchanger is provided at the top of the keel. Side frames connected to a negative pressure fan are provided on the vertical side walls of the keel. Guide rails symmetrically arranged on both sides of the drying belt are fixed inside the keel. The position of the guide rails is higher than that of the side frames, and the guide rails are in sliding contact with the vertical side walls of the drying belt.

[0013] Through the above technical solution, the structure of the working section is optimized. The keel is used to enhance the structural strength. The top frame is used for top air intake, the side frames are provided for horizontal exhaust, the guide rails limit the drying belt and can also prevent the biogas residues from falling. The guide rails are narrower at the top and wider at the bottom, playing an air guiding role, so that the hot air blown on the rear side wall of the skin can flow forward and finally pass through the biogas residues and the drying belt from top to bottom to complete drying.

[0014] Furthermore, a ridger is connected to the keel. The ridger is arranged above a part of the inner side of the working section in the drying zone. The ridger includes a first actuator and a second actuator, and the first actuator and the second actuator can successively form ridging grooves at different positions of the biogas residue.

[0015] Through the above technical solution, to ensure that the deep biogas residue liquid can fully contact the hot air flow, the ridger rotates, and the flat biogas residue is formed into parallel ridging grooves along the traveling direction through the support arm. Moreover, the first actuator and the second actuator are arranged in sequence, and the support arms of the first actuator and the second actuator are arranged in a front-back staggered manner. The first actuator forms ridging grooves in the flat biogas residue, and the second actuator forms ridging grooves again at the raised positions of the biogas residue with ridging grooves and piles the biogas residue to the position of the old ridging grooves, performing alternating turning of the biogas residue to ensure that the biogas residue is fully turned.

[0016] Furthermore, the thin-walled plate adopts a serpentine coiled structure. The thin-walled plate and the fins are arranged in a grid-like and staggered manner. Both ends of the thin-walled plate are externally connected to a heat source through a circulating water pipe, and a protective net is arranged above the thin-walled plate.

[0017] Through the above technical solution, to enable the hot air to fully contact the biogas residue on the drying zone, the intake air is separated into multiple independent airflows by the thin-walled plate and the fins. In this way, after the intake air, it can be blown more dispersedly onto the vertical inner wall at the rear side of the working section and then turn back forward, evenly sweeping across the biogas residue on the drying zone from back to front. The circulating water pipe keeps the thin-walled plate in a stable high-temperature state, avoiding incomplete drying of the biogas residue caused by insufficient heat.

[0018] Furthermore, a drying zone cleaning mechanism is arranged on the main body. The drying zone cleaning mechanism includes a spray pipe and a duct. The spray pipe is erected directly above the drying zone. The spray pipe is connected to a flushing pipe through a three-way reversing valve. The flushing pipe is located downstream of the separation of the drying zone and the biogas residue in the discharge section. The duct is connected to the outlet of the negative pressure fan and extends to downstream of the separation of the drying zone and the biogas residue in the discharge section.

[0019] Through the above technical solution, to improve the continuous operation stability of the equipment and prevent the biogas residue from blocking the mesh holes of the drying zone. When not in use, the spray pipe can flush the drying zone. When in use, the spray pipe can also be manually controlled to be opened to play a fire prevention role. During the drying process, the duct collects the high-temperature and high-humidity tail gas and guides it to the downstream of the drying zone. After the biogas residue is separated from the drying zone, it blows and cleans the drying zone, making reasonable use of the tail gas. At the same time, before the blowing, the high-pressure water flow of the flushing pipe can be used to clean the drying zone, and then the high-temperature air flow is used for blowing, which can make the drying zone cleaned thoroughly and dried quickly.

[0020] Further, a waste heat recovery mechanism is provided on the main body. The waste heat recovery mechanism includes a collecting air duct connected to the outlet of the negative pressure fan. A dehumidifier is provided downstream of the collecting air duct, and a distribution air duct is installed at the outlet end of the dehumidifier. The distribution air duct is communicated with the air inlet of the air heat exchanger.

[0021] Through the above technical solution, to optimize the energy consumption of the equipment, during the drying process, after the negative pressure fan draws out the high-temperature and high-humidity tail gas from the working section, it will be concentrated by the collecting air duct to the position of the dehumidifier. On the premise of ensuring that the waste heat is fully retained, the water vapor in the tail gas is separated, and then the dried tail gas is supplemented to the position of the air heat exchanger through the distribution air duct for secondary heating and circulating drying of the biogas residue.

[0022] Further, a gas selection and circulation mechanism is provided on the main body. The gas selection and circulation mechanism includes a return air duct connected between the outlet of the negative pressure fan downstream and the air inlet of the air heat exchanger upstream. An exhaust gas pipe is installed at the outlet of the negative pressure fan upstream, and a fresh air pipe is installed at the air inlet of the air heat exchanger downstream.

[0023] Through the above technical solution, to avoid the influence of water vapor in the tail gas on the waste heat recovery efficiency, the high-humidity upstream tail gas is directly discharged from the exhaust gas pipe, and only part of the high-temperature tail gas downstream is re-introduced into the main body through the return air duct for secondary utilization. Moreover, a new drying gas source is supplemented by the fresh air pipe, while directly utilizing the waste heat of the untreated tail gas, minimizing the influence of water vapor in the tail gas on the drying progress as much as possible.

[0024] The beneficial effects of the present invention are as follows: Through the settings of the main body, drying belt, feeder, negative pressure fan and air heat exchanger in the present invention, biogas residues with different humidities are flattened by the feeder on the drying belt with different thicknesses. On the premise of ensuring the consistency of the outlet humidity, the drying adaptability of the equipment is improved. Then, the air inlet path is optimized through the air heat exchanger, so that the hot air is first blown to the side of the drying belt away from the negative pressure fan, and then attracted forward by the negative pressure of the negative pressure fan to complete the hot air coverage of the entire drying belt with a shorter path. Through the structural optimization of the working section in the present invention, a bearing frame is provided below the drying belt to ensure the levelness of the drying belt, avoid the collapse of the drying belt caused by the air pressure difference and the gravity of the biogas residue, ensure the stability of the thickness of the biogas residue, and use the bristles to penetrate the mesh holes of the drying belt from bottom to top to keep the biogas residue fluffy to prevent caking and prevent the mesh holes from being blocked to ensure the smooth passage of hot air. Through the setting of the ridging device in the present invention, when the drying belt drives the biogas residue to move, ridging grooves are opened on the biogas residue by the first actuator and the second actuator, so that the biogas residue forms a plurality of corrugated inclined planes almost perpendicular to the hot air flow direction, greatly increasing the contact area between the hot air and the biogas residue, turning the deep biogas residue to the shallow layer, ensuring the uniform drying of the biogas residue layer, and improving the outlet quality. Description of the Drawings

[0025] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is a schematic diagram of the positions among the feeder, the feeding section and the drying belt of the present invention; Figure 3 is a structural diagram of the feeding section and the working section of the present invention in the state of removing the skin; Figure 4 is a schematic structural diagram of the air heat exchanger of the present invention; Figure 5 is a schematic diagram of the state of the biogas residue in different working sections of the present invention; Figure 6 is a schematic structural diagram of the present invention with a drying belt cleaning mechanism added; Figure 7 is a sectional view of the present invention after adding the drying belt cleaning mechanism; Figure 8 is a position diagram among the discharging section, the drying belt cleaning mechanism and the drying belt of the present invention; Figure 9 is a schematic structural diagram of the present invention with a waste heat recovery mechanism added; Figure 10 is a schematic structural diagram of one of the carrier frames in the working section of the present invention; Figure 11 is a schematic structural diagram of the present invention with a gas selection and circulation mechanism added.

[0026] Reference numerals: 1, feeder; 11, lifting structure; 12, distributor; 13, flattening member; 2, feeding section; 21, driving roller; 211, tensioning frame; 22, first return and reversing roller; 3, working section; 31, skin; 32, contact area; 33, guide rail; 34, return air area; 35, carrier frame; 351, support roller; 352, support hair; 36, keel; 37, side frame; 38, top frame; 39, ridging tool; 391, first actuator; 392, second actuator; 4, discharging section; 41, discharge port; 42, rotary roller; 43, receiving hopper; 44, second return and reversing roller; 5, air heat exchanger; 51, housing; 52, thin wall plate; 53, fin; 54, air guide channel; 55, protection net; 56, circulating water pipe; 6, negative pressure fan; 61, air duct; 62, collecting duct; 63, dehumidifier; 64, air distribution pipe; 65, return pipe; 66, fresh air pipe; 67, waste gas pipe; 7, drying belt; 71, mesh hole; 8, spray pipe; 81, scouring pipe; 9, biogas residue; 91, furrow. Detailed implementation manners

[0027] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] As Figure 1 - Figure 10 shown, this embodiment provides a biogas residue drying and processing device. After the biogas residue 9 undergoes solid-liquid separation, the wet material with a moisture content of about 70% - 80% needs to be dried before it can be further utilized. Specifically, the wet material needs to be evenly spread on the drying belt 7. After the feeding is completed, the wet material moves through the drying belt 7 and is sent into the drying area. When the hot air flows through the material layer, the water vapor is carried away by convection. Subsequently, the dried material is collected uniformly, and the tail gas is discharged after being cooled. To overcome the problems existing in the prior art, the actual problem to be solved by this solution is how to ensure that the biogas residue 9 on the drying belt 7 will not be affected by the hot air flow path and show inconsistent drying degrees.

[0029] Specifically, regarding the main body, refer to Figure 1 , the main body includes a feeding section 2, a working section 3, and a discharging section 4. The feeding section 2, the working section 3, and the discharging section 4 are connected end to end and arranged in sequence from left to right. The feeding section 2 is used to input the wet material. A discharging port 41 is provided at the right end of the discharging section 4 to discharge the dried material. Among them, skins 31 are provided on the outer sides of the feeding section 2, the working section 3, and the discharging section 4 to form a box-type space and reduce the escape of heat and air flow; Regarding the drying belt 7, refer to Figure 2 , the material of the drying belt 7 is synthetic polyester, with mesh holes 71, and the mesh holes 71 are micro sieve grids, suitable for fine particles, reducing the spillage of the biogas residue 9. The drying belt 7 is arranged in a continuous and coiled manner in the main body for circulating feeding. The drying belt 7 divides the internal space of the main body vertically into a contact area 32 and a return air area 34. The biogas residue 9 is located in the contact area 32 and is dried by contacting the hot air entering from above. The tail gas with water vapor will pass downward through the biogas residue 9 and the drying belt 7 and then enter the return air area 34, waiting to be discharged centrally. Specifically, the drying belt 7 is of a two-layer type, one layer is a chain mesh, and there are sprockets and guide wheels on both sides of the chain mesh to play a supporting and guiding role, and the other layer is a polyurethane mesh belt to prevent the biogas residue 9 from sticking; Regarding the feeder 1, the feeder 1 adopts a double - helix distributor to ensure that the biogas residue 9 is evenly transported onto the drying belt 7. The feeder 1 is liftably installed on the feeding section 2, and the stacking thickness of the biogas residue 9 can be adjusted, thereby ensuring the consistency of drying. Specifically, humidity sensors are provided in the feeding section 2 and the discharging section 4. When the humidity of the incoming material is high, the stacking thickness of the biogas residue 9 is reduced, so that hot air can pass through the biogas residue 9 more quickly and carry away water vapor, and the humidity of the discharged material can be ensured to be within a reasonable range. Similarly, when the humidity of the incoming material is low, the stacking thickness of the biogas residue 9 is increased. On the premise of ensuring the reasonable humidity of the discharged material, more biogas residue 9 can be processed per unit time, improving efficiency. The feeder 1 flattens the biogas residue 9 with different thicknesses on the upper surface of the drying belt 7. After flattening, the biogas residue 9 at the bottom layer can evenly contact the hot air, and it will not cause incomplete drying of the deep biogas residue 9 at the large - thickness position because the hot air all flows downward from the biogas residue 9 with a low thickness; Regarding the negative - pressure fan 6, refer to Figure 1 , the negative - pressure fan 6 is fixed on the vertical side wall of the working section 3. The main body is installed side by side with the negative - pressure fan 6, reducing the overall height of the equipment for convenient assembly. The negative - pressure fan 6 is connected to the return air area 34, and it can also ensure that the air flow can pass through the biogas residue 9 from top to bottom and then be uniformly discharged. The negative - pressure fan 6 sucks the air in the contact area 32 into the return air area 34, and then continuously discharges the air in the return air area 34 from the main body. The hot air in the entire drying area operates under negative pressure, making the flow direction of the hot - air flow clearer, reducing the residence time of the hot air in the main body, and increasing the heat - exchange efficiency; Regarding the air heat exchanger 5, refer to Figure 1, the air heat exchanger 5 has a thin-walled plate 52 filled with hot water. The thin-walled plate 52 is filled with hot water inside and is arranged directly above the working section 3. An outer shell 51 is sleeved outside the thin-walled plate 52. The outer shell 51 is communicated with the contact area 32, so that the outside air can fully contact and heat up with the thin-walled plate 52 under the guidance of the outer shell 51, and then blow downward to the position of the biogas residue 9. Among them, fins 53 are arranged on the outer wall of the thin-walled plate 52. The fins 53 are made of heat-conducting materials, which can increase the actual contact area between the air and the thin-walled plate 52, and thus exchange heat more efficiently, so that the incoming air can be heated to a higher temperature in a short time, and the biogas residue 9 below can be efficiently dried. At the same time, the lower end of the fin 53 is inclined away from the negative pressure fan 6, that is, the incoming air will blow backward, and then under the attraction of the front negative pressure fan 6, it will flow forward across the drying zone 7. Compared with the vertical downward air intake direction and the long-distance flow along the advancing direction of the drying zone 7, the flow direction of the hot air that is inclined backward and then turns forward can make the hot air cover the entire span of the drying zone 7 with a shorter flow path. That is to say, targeted hot air compensation can be carried out for the low-flow velocity area, ensuring that the biogas residue 9 on the side of the drying zone 7 far from the negative pressure fan 6 can also be fully penetrated and dried by the hot air from top to bottom. It can also ensure that the hot air absorbing water vapor flows out of the main body as soon as possible, preventing the water vapor in the main body from being saturated and condensing again in the low-flow velocity area or low-temperature area, thereby ensuring that the entire drying zone 7 is within the range of hot air coverage with rapid replacement during drying.

[0030] In a further embodiment, to ensure that the drying zone 7 passes horizontally, refer to Figure 2 , the working section 3 includes a carrier frame 35. The carrier frame 35 has rod-shaped legs and a horizontally extending horizontal rod. The carrier frame 35 is fixed at the bottom surface of the working section 3. The carrier frame 35 is arranged below a part of the drying zone 7 located inside the working section 3. The horizontal rod of the carrier frame 35 supports a part of the drying zone 7 located inside the working section 3, ensuring that the drying zone 7 is flat and preventing the middle part of the drying zone 7 from collapsing. It can ensure that the thickness of the feed is controllable, preventing the biogas residue 9 from gathering at the collapsed position downward and resulting in an excessive stacking thickness and unable to be thoroughly dried. The carrier frame 35 is in sliding contact with the drying zone 7, without affecting the horizontal movement of the drying zone 7.

[0031] In a further embodiment, to adapt to biogas residues 9 with different humidities, refer to Figure 2, a lifting structure 11 is provided at the lower part of the feeder 1. Specifically, the lifting structure 11 includes a fixed frame, a sliding frame, and a vertical screw. The fixed frame is fixedly connected to the top surface of the feeding section 2. The vertical screw is connected to the fixed frame through a nut. The sliding frame is rotatably connected to the vertical screw, and the sliding frame is fixedly connected to the vertical side wall of the feeder 1. During adjustment, by rotating the vertical screw to jack up the sliding frame, the feeder 1 can be raised. And at the overlapping position of the fixed frame and the sliding frame in the height direction, a locking bolt is provided. The locking bolt passes through the vertical sliding opening on the fixed frame and is connected to the sliding frame. After adjustment, the fixed frame and the sliding frame can be fixed by the locking bolt to ensure the stable position during use. And, please also refer to Figure 2 , a distributor 12 is provided at the outlet of the feeder 1. The distributor 12 has multiple outlets, which can disperse and feed the biogas residue 9 front and back, facilitating the subsequent flattening work. A flattening member 13 is provided at the outlet of the distributor 12. The flattening member 13 is located downstream of the distributor 12. And the flattening member 13 is of a corrugated structure, which can push the biogas residue 9 to a position perpendicular to the advancing direction of the drying belt 7, quickly flatten the biogas residue 9. And there is a material passing space between the bottom surface of the flattening member 13 and the top surface of the drying belt 7, which can control the thickness of the biogas residue 9 after flattening. Specifically, the feeder 1 can also use a combination of a screw feeder and a spiral distributor (as shown in Figure 11 ). The feeder 1 is horizontally placed upstream of the drying belt 7 to convey the semi-dry biogas residue 9 to the upstream of the drying belt 7 and disperse it for spreading to complete the feeding. Other structures that can achieve feeding and replenishing are not elaborated here one by one. When the biogas residue 9 is relatively wet, the lifting structure 11 lowers the height of the feeder 1 to reduce the material passing space between the bottom surface of the flattening member 13 and the top surface of the drying belt 7, reduce the thickness of the biogas residue 9, and disperse the feeding through the distributor 12 and flatten it through the flattening member 13 to prevent incomplete drying caused by uneven stacking during drying. When the biogas residue 9 is relatively dry, the height of the feeder 1 can be increased to increase the amount of biogas residue 9 entering per unit time and improve the drying efficiency.

[0032] In a further embodiment, refer to Figure 2 、 Figure 3 and Figure 8, a driving roller 21 is built in the feeding section 2. The driving roller 21 is externally connected to a motor to drive the rotation of the drying belt 7. At the same time, a tensioning frame 211 is provided at the end of the driving roller 21 to straighten the drying belt 7 and prevent the lower part of the drying belt 7 from directly contacting the ground. Specifically, the tensioning frame 211 includes a sliding guide frame, a sliding bearing seat and an adjusting screw. By rotating the adjusting screw, the sliding bearing seat can be pulled to horizontally slide within the sliding guide frame, thereby causing the driving roller 21 to move left and right, and the tensioning action can be achieved. A rotary roller 42 at the same height as the driving roller 21 is built in the discharging section 4. The rotary roller 42 is an idler. A first return turning roller 22 and a second return turning roller 44 are respectively provided below the driving roller 21 and the rotary roller 42 in the feeding section 2 and the discharging section 4. The drying belt 7 is wound between the driving roller 21, the rotary roller 42, the first return turning roller 22 and the second return turning roller 44 to form a belt structure, which can rotate to realize continuous conveying of the biogas residue 9. Moreover, the first return turning roller 22 and the second return turning roller 44 make the lower part of the drying belt 7 located at the lower part outside the main body and in contact with the external air, which is convenient for maintenance from the outside of the equipment.

[0033] In a further embodiment, to improve the dehydration speed of the biogas residue 9 on the drying belt 7, referring to Figure 10 , a supporting roller 351 is provided on the upper part of the bearing frame 35. The supporting rollers 351 are arranged in the front-rear direction and extend horizontally. The supporting rollers 351 lift the drying belt 7. Moreover, the supporting rollers 351 are in rolling contact with the lower surface of a part of the drying belt 7 located inside the working section 3. The rolling support reduces wear. Supporting hairs 352 are installed on the circumferential side wall of the supporting roller 351 along the tangent direction. The supporting hairs 352 can be inserted into and pulled out of the mesh holes 71 from bottom to top when the supporting roller 351 rotates. By using the supporting hairs 352 to insert into the mesh holes 71, the biogas residue 9 above the drying belt 7 is jacked up, making the biogas residue 9 fluffy and porous, which is more convenient for air to pass through. And it can also prevent the biogas residue 9 from being compacted on the drying belt 7 due to the unidirectional flow of hot air, resulting in caking. At the same time, the insertion and extraction of the supporting hairs 352 push the biogas residue 9 in the mesh holes 71 upward, penetrating the mesh holes 71 to avoid blockage, so that the hot air can pass through the stacked biogas residue 9 more smoothly and evenly. It should be noted that the supporting hairs 352 extend along the tangent direction of the circumferential side wall of the supporting roller 351, and the free ends of the supporting hairs 352 are arranged against the advancing direction of the drying belt 7, so that it is easier to penetrate into the mesh holes 71. Therefore, an external power source can be used to make all the supporting rollers 351 rotate counterclockwise. In this way, during the movement of the drying belt 7 from left to right, the supporting hairs 352 can penetrate into the mesh holes 71 more easily and frequently, making the biogas residue 9 more fluffy and the downward flow of hot air more smooth; Specifically, at least one supporting roller 351 (not shown in the figure) can also be arranged downstream of the drying belt 7. After feeding, the supporting roller 351 drives the supporting hairs 352 to rotate to brush the surface of the drying belt 7 to prevent material adhesion and ensure complete discharging.

[0034] In a further embodiment, the structure of the working section 3 is optimized. Referring to Figure 3 , the working section 3 includes a keel 36, which adopts a galvanized steel self-supporting steel frame. The keel 36 is used to enhance the structural strength of the main body and facilitate the fixing of the skin 31. The skin 31 is divided into two layers, the inner and outer layers, which are respectively fixed on the inner and outer sides of the keel 36. The self-thickness of the keel 36 can form a sandwich layer in the skin 31 to fill the heat-insulating material to delay heat dissipation and reduce heat loss. At the same time, a top frame 38 connected to the air heat exchanger 5 is provided at the top of the keel 36 for top air intake and heating by the air heat exchanger 5. A side frame 37 connected to the negative pressure fan 6 is provided on the vertical side wall of the keel 36. By using side exhaust instead of bottom exhaust, the negative pressure fan 6 can be arranged side by side with the main body without lifting the main body above the negative pressure fan 6, reducing the equipment height and facilitating the maintenance and installation of the main body. At the same time, guide rails 33 symmetrically arranged on both sides of the drying zone 7 are fixed inside the keel 36. The position of the guide rails 33 is higher than that of the side frame 37, which does not affect the separation of the internal contact area 32 and the return air area 34 of the main body by the drying zone 7. It should be emphasized that the guide rails 33 are in sliding contact with the vertical side walls of the drying zone 7. The guide rails 33 limit the drying zone 7 to prevent it from deviating forward and backward, and can also prevent the biogas residue 9 from falling from the front and rear sides of the drying zone 7. The upper part of the guide rails 33 is narrow and the lower part is wide, which plays a role in air diversion, so that the hot air blown on the inner wall of the rear side of the skin 31 can flow downward and be attracted forward by the negative pressure fan 6 in the front, forming a flowing hot air from top to bottom and from back to front. Finally, the hot air passes through the biogas residue 9 and the drying zone 7 from top to bottom to complete the drying action.

[0035] In a further embodiment, to ensure that the deep biogas residue 9 can also fully contact the hot air flow, referring to Figure 5 and Figure 7, a ridger 39 is connected to the keel 36. The ridger 39 includes a horizontally arranged rotating shaft in the front-rear direction and arms fixed on the circumferential side wall of the rotating shaft. The ridger 39 is arranged above a part of the inner side of the drying zone 7 located in the working section 3. By rotating the ridger 39, parallel ridges 91 are formed in the smooth biogas residue 9 along the traveling direction through the arms. The ridger 39 includes a first actuator 391 and a second actuator 392. Both the first actuator 391 and the second actuator 392 are rotating shafts with arms, but the arms of the two are arranged staggeredly in the front-rear direction. And at least one first actuator 391 and one second actuator 392 are arranged on the working section 3. The first actuator 391 forms multiple parallel ridges 91 in the smooth biogas residue 9 along the advancing direction of the drying zone 7, making the upper surface of the biogas residue 9 uneven. And the hot air blows from top to bottom and from back to front, and can act on the windward surface of the ridges 91 almost vertically, greatly increasing the windward area of the biogas residue 9 and exposing the deep biogas residue 9 to the shallow layer, reducing the influence of the moisture in the upper biogas residue 9 on the drying progress of the lower biogas residue 9. At the same time, the arm of the second actuator 392 corresponds to the convex position of the biogas residue 9 where the ridges 91 have been formed, that is, the arm of the second actuator 392 is located at the gap between the adjacent arms of the first actuator 391. Ridges 91 are formed again at the convex position of the biogas residue 9 and the biogas residue 9 is piled up at the position of the old ridges 91, turning the deep biogas residue 9 that has not been turned out by the first actuator 391 to the shallow layer, and alternately turning the biogas residue 9, greatly improving the drying efficiency of the deep biogas residue 9. And multiple groups of the first actuator 391 and the second actuator 392 can be set to perform multiple reciprocating turnings, and the rapid drying of the biogas residue 9 can be completed by using a shorter drying path.

[0036] In a further embodiment, to enable the hot air to fully contact the biogas residue 9 on the drying zone 7, referring to Figure 4 , the thin-walled plate 52 adopts a serpentine coiled structure and has a certain length in the height direction. The thin-walled plate 52 and the fins 53 are arranged in a grid-like staggered manner, separating the intake air into multiple independent air guiding channels 54 through the thin-walled plate 52 and the fins 53. The thin-walled plate 52 is arranged in a structure where the bottom disperses and moves away from each other to the left and right, and is matched with the fins 53 whose bottom is inclined backward. For such air guiding channels 54, after the intake air enters, it can be blown more dispersedly to the vertical inner wall at the rear side of the working section 3, fully covering the main internal space between the two air heat exchangers 5. After the hot air turns back forward, it evenly sweeps across the biogas residue 9 on a longer length of the drying zone 7 from back to front. At the same time, referring to Figure 4 , both ends of the thin-walled plate 52 are externally connected to a heat source through a circulating water pipe 56. The circulating water pipe 56 keeps the thin-walled plate 52 in a stable high-temperature state, avoiding incomplete drying of the biogas residue 9 caused by insufficient heat. A protective net 55 is arranged above the thin-walled plate 52 to filter the intake air and prevent solid debris from entering; Preferably, the thin wall plate 52 in the air heat exchanger 5 can also use a plate heat exchange structure, a shell and tube heat exchange structure or a finned tube heat exchange structure. Based on the ability to provide a large heat exchange contact area, it can be replaced according to actual construction, which will not be elaborated here.

[0037] In a further embodiment, to improve the continuous operation stability of the equipment, a drying belt cleaning mechanism is provided on the main body to prevent the mesh holes 71 of the drying belt 7 from being blocked by the biogas residue 9. Refer to Figure 6 - Figure 8 , the drying belt cleaning mechanism includes a spray pipe 8 and a duct 61. The spray pipe 8 is installed directly above the drying belt 7. When drying is not in progress or during the drying interval, the spray pipe 8 can flush the drying belt 7. When in use for drying, the spray pipe 8 can also be controlled to open to play a fire prevention role, that is, if necessary, water mist spraying will be carried out above the biogas residue 9. Specifically, when the temperature inside the main body exceeds the limit value, the temperature sensor installed in the working section 3 will activate the valve of the spray pipe 8, and the drying belt 7 will be sprayed through the on-site water supply system. An additional manual valve can also be set to activate the spray system at any time, with good fire prevention effect; Please also refer to Figure 8 , the spray pipe 8 is connected to a flushing pipe 81 through a three-way reversing valve. The flushing pipe 81 is located downstream of the separation of the drying belt 7 and the biogas residue 9 in the discharge section 4. The duct 61 is connected to the outlet of the negative pressure fan 6 and extends to the downstream of the separation of the drying belt 7 and the biogas residue 9 in the discharge section 4. During the drying process, the duct 61 collects the high-temperature and high-humidity tail gas and guides it to the downstream of the drying belt 7. After the biogas residue 9 is separated from the drying belt 7, the drying belt 7 is purged and cleaned, and the tail gas is reasonably utilized. At the same time, before purging, the high-pressure water flow of the flushing pipe 81 can be used to clean the drying belt 7, and then purged with high-temperature air flow, so that the drying belt 7 can be thoroughly cleaned and quickly dried. A receiving hopper 43 is provided at the lower part of the discharge section 4 to collect the flushed biogas residue 9 for secondary recovery, reducing material waste.

[0038] In a further embodiment, to optimize the energy consumption of the equipment, refer to Figure 9 , a waste heat recovery mechanism is provided on the main body. The waste heat recovery mechanism includes a collecting duct 62. The collecting duct 62 is connected to the outlet of the negative pressure fan 6. A dehumidifier 63 is provided downstream of the collecting duct 62. During the drying process, after the negative pressure fan 6 draws out the high-temperature and high-humidity tail gas from the working section 3, it will be concentrated by the collecting duct 62 to the position of the dehumidifier 63. On the premise of ensuring that the waste heat is fully retained, the water vapor in the tail gas is separated. A distribution duct 64 is installed at the outlet end of the dehumidifier 63. The distribution duct 64 is communicated with the air inlet of the air heat exchanger 5, and then the dried tail gas is supplemented to the position of the air heat exchanger 5 through the distribution duct 64 for secondary heating and circulating drying of the biogas residue 9; Specifically, the dehumidifier 63 uses an electrostatic adsorption dehumidifier or a rotary adsorption dehumidifier. While removing water vapor from the tail gas, it will not reduce the temperature of the tail gas like a condensation dehumidifier, and retains the heat of the tail gas to the greatest extent to recover most of the heat to ensure efficient drying. The recycled tail gas is reheated to reduce tail gas emissions and heat loss.

[0039] In a further embodiment, referring to Figure 11 , a gas selection and circulation mechanism is provided on the main body. The gas selection and circulation mechanism includes a return pipe 65, and the return pipe 65 is connected between the outlet of the negative pressure fan 6 downstream and the air inlet of the air heat exchanger 5 upstream. Specifically, the negative pressure fan 6 downstream can be the most downstream negative pressure fan 6, and the air heat exchanger 5 upstream can be the most upstream air heat exchanger 5 and the next two consecutive air heat exchangers 5. With this design, the tail gas with low humidity and high temperature can be directly led out for direct use. Moreover, these tail gases are led to the position of the upstream marsh slag 9 with high humidity. The trace water vapor in the recycled tail gas can be ignored compared to the water content of the just-dried marsh slag 9. Therefore, these tail gases can be directly used without treatment and will not affect the drying progress. Similarly, an exhaust pipe 67 is installed at the outlet of the negative pressure fan 6 located upstream. These high-humidity tail gases cannot be directly utilized and are directly led to the deodorizing tail gas machine for treatment and emission. A fresh air pipe 66 is installed at the air inlet of the air heat exchanger 5 located downstream to introduce external air into the main body, ensuring that the total amount of air for drying in the main body is sufficient and guaranteeing the drying efficiency. Through the setting of the gas selection and circulation mechanism, while directly utilizing the waste heat of the untreated tail gas, the influence of the water vapor in the tail gas on the drying progress is minimized as much as possible.

[0040] The above is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention.

Claims

1. A biogas residue drying and processing equipment, characterized in that: include: A main body, the main body comprising a feeding section (2), a working section (3) and a discharging section (4), the feeding section (2), the working section (3) and the discharging section (4) being arranged end to end, and the outer sides of the feeding section (2), the working section (3) and the discharging section (4) are provided with a skin (31); A drying belt (7), the drying belt (7) is arranged in a coiled manner through the main body, the drying belt (7) has mesh holes (71), and the drying belt (7) divides the internal space of the main body into a contact area (32) and a return air area (34) in upper and lower parts; A feeder (1), the feeder (1) being mounted on the feed section (2) in a liftable manner, the feeder (1) spreading the biogas residue (9) of different thicknesses on the upper surface of the drying belt (7); A negative pressure fan (6), the negative pressure fan (6) being fixed to a vertical side wall of the working section (3), the negative pressure fan (6) continuously extracting air from the contact area (32) and the return air area (34); An air heat exchanger (5), the air heat exchanger (5) comprising a thin-walled plate (52) filled with hot water, an outer shell (51) being provided on the outer side of the thin-walled plate (52), the outer shell (51) being in communication with the contact area (32), a fin (53) being provided on the outer wall of the thin-walled plate (52), the lower end of the fin (53) being inclined in a direction away from the negative pressure fan (6) so that the incoming air is sucked by the negative pressure fan (6) across the drying zone (7).

2. The biogas residue drying and processing equipment according to claim 1, characterized in that: The working section (3) comprises a bearing frame (35), the bearing frame (35) being fixed to the bottom surface of the working section (3), the bearing frame (35) being arranged below a portion of the drying belt (7) located inside the working section (3), and the bearing frame (35) being in sliding contact with the drying belt (7).

3. The biogas residue drying and processing equipment according to claim 2, characterized in that: A support roller (351) is provided on the upper part of the support frame (35). The support roller (351) is in rolling contact with the lower surface of a portion of the drying belt (7) located inside the working section (3). Support hairs (352) are installed on the circumferential side wall of the support roller (351) along the tangential direction. The support hairs (352) can be inserted and pulled out of the mesh (71) from bottom to top when the support roller (351) rotates.

4. The biogas residue drying and processing equipment according to claim 2, characterized in that: A lifting structure (11) is provided at the lower part of the feeder (1), and the lifting structure (11) is fixedly connected to the top surface of the feeding section (2). A distributor (12) is provided at the outlet of the feeder (1), and the distributor (12) has a plurality of outlets. A flattening piece (13) is provided at the outlet of the distributor (12), and a material passing space is left between the bottom surface of the flattening piece (13) and the top surface of the drying belt (7).

5. The biogas residue drying and processing equipment according to claim 1, characterized in that: The working section (3) comprises a keel (36), a top frame (38) connected to the air heat exchanger (5) is provided at the top of the keel (36), a side frame (37) connected to the negative pressure fan (6) is provided on the vertical side wall of the keel (36), guide rails (33) symmetrically arranged on both sides of the drying belt (7) are fixed inside the keel (36), the guide rails (33) are located higher than the side frames (37), and the guide rails (33) are in sliding contact with the vertical side walls of the drying belt (7).

6. The biogas residue drying and processing equipment according to claim 5, characterized in that: The keel (36) is connected to a ridging device (39), and the ridging device (39) is arranged above a portion of the drying belt (7) located inside the working section (3). The ridging device (39) comprises an actuator 1 (391) and an actuator 2 (392), and both the actuator 1 (391) and the actuator 2 (392) are rotating shafts with supporting arms, and the supporting arms of the actuator 2 (392) are located in the gap between the adjacent supporting arms of the actuator 1 (391).

7. The biogas residue drying and processing equipment according to claim 6, characterized in that: The thin-walled plates (52) adopt a serpentine coiling structure, the lower parts of the thin-walled plates (52) are spaced apart from each other along the extension direction of the drying belt (7), the thin-walled plates (52) and the fins (53) are arranged in a grid-like manner to form an air guide channel (54), both ends of the thin-walled plates (52) are connected to an external heat source through a circulating water pipe (56), and a protective net (55) is provided above the thin-walled plates (52).

8. The biogas residue drying and processing equipment according to claim 1, characterized in that: The main body is provided with a drying belt cleaning mechanism, the drying belt cleaning mechanism comprising a spray pipe (8) and an air guide pipe (61), the spray pipe (8) being mounted directly above the drying belt (7), the spray pipe (8) being connected to a flushing pipe (81) via a three-way reversing valve, the flushing pipe (81) being located downstream of the drying belt (7) and the biogas residue (9) being separated in the discharge section (4), and the air guide pipe (61) being connected to the outlet of the negative pressure fan (6) and extending to the downstream of the drying belt (7) and the biogas residue (9) being separated in the discharge section (4).

9. The biogas residue drying and processing equipment according to claim 1, characterized in that: A waste heat recovery mechanism is provided on the main body, the waste heat recovery mechanism comprising an air collecting pipe (62), the air collecting pipe (62) being connected to the outlet of the negative pressure fan (6), a dehumidifier (63) being provided downstream of the air collecting pipe (62), an air distribution pipe (64) being installed at the outlet end of the dehumidifier (63), and the air distribution pipe (64) being communicated with the air inlet of the air heat exchanger (5).

10. The biogas residue drying and processing equipment according to claim 1, characterized in that: The main body is provided with an air selection circulation mechanism, the air selection circulation mechanism comprising a return pipe (65), the return pipe (65) being connected between the outlet of the downstream negative pressure fan (6) and the air inlet of the upstream air heat exchanger (5), an exhaust pipe (67) being installed at the outlet of the upstream negative pressure fan (6), and a fresh air pipe (66) being installed at the air inlet of the downstream air heat exchanger (5).

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