A starch production plant wastewater treatment device

Abstract

The application provides a starch production workshop sewage treatment device, and relates to the technical field of sewage treatment. The device comprises a sewage treatment tank, a treatment mechanism for conveniently filtering sewage is arranged on the sewage treatment tank, the treatment mechanism comprises a coarse filter grid structure and a fine filter grid structure, the coarse filter grid structure and the fine filter grid structure are fixedly installed on the inner side wall of the sewage treatment tank, and the fine filter grid structure is located behind the coarse filter grid structure. The two-stage heating structure of the coarse filter grid structure and the fine filter grid structure is used in cooperation, so that the sewage is heated in a gradient heating mode. The preliminary heating is completed in the coarse filter stage, and the secondary heating is completed in the fine filter stage. According to the characteristics that the starch sewage contains a large number of starch particles, the gradient heating can make the water temperature rise stably in stages, avoid local high-temperature points formed by single rapid heating, control the water temperature below the starch gelatinization temperature throughout the process, and prevent the starch particles from being gelatinized due to local overheating.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and more specifically, relates to a wastewater treatment device for a starch production workshop. Background Technology

[0002] Wastewater from wheat starch production workshops is the process drainage generated from all stages of wheat raw material washing, grinding, starch screening, and slurry purification. The water contains wheat bran fiber, free fine starch particles, soluble plant protein, and sugars. It is classified as high-suspended solids and high-COD organic wastewater from agricultural and sideline food processing. If it is discharged directly into the downstream wastewater treatment unit without effective pretreatment, the unsettled fine starch particles will accumulate and clog pipes and sedimentation tank packing. At the same time, the discharge of high-concentration organic matter will cause eutrophication of the water body and blackening and foul odor of the water.

[0003] The Chinese patent publication number is CN119118257A, which discloses a multi-stage potato starch wastewater treatment device. This invention drives the lifting frame to rise, and then drives the movable screen to rotate 180 degrees through the movement of the reciprocating box. This facilitates the discharge of solid waste accumulated on the movable screen into the isolation tank, so that the device can continuously block solid waste in potato starch wastewater and automatically discharge the blocked material, reducing the amount of manual labor and improving the pretreatment efficiency of potato starch wastewater.

[0004] Existing wastewater treatment methods for starch processing plants have the following drawbacks: 1. In the existing wastewater treatment process of starch production workshop, the influent water temperature is low in winter, usually only 10 to 15 degrees Celsius. The low water temperature will slow down the settling speed of starch particles in the wastewater. A large number of fine starch particles cannot be effectively settled in the sedimentation tank. After entering the subsequent biological treatment unit with the water flow, it will increase the treatment load of the biological treatment unit. 2. In the existing technology, if low-temperature wastewater is to be heated, an independent heating device is usually set up after the bar screen unit, which separates the filtration function and the heating function into two independent units. This not only increases the overall footprint of the treatment device, but also requires the wastewater to pass through an additional water layer before being heated after being filtered by the bar screen, resulting in relatively low heat exchange efficiency.

[0005] In view of this, we have studied and improved the existing structure and its shortcomings, and provided a wastewater treatment device for starch production workshops, in order to achieve a more practical purpose. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a wastewater treatment device for starch production workshops.

[0007] A wastewater treatment device for a starch production workshop includes a wastewater treatment tank. The wastewater treatment tank is equipped with a treatment mechanism for filtration of wastewater. The treatment mechanism includes a coarse filter screen structure and a fine filter screen structure, both fixedly installed on the inner wall of the wastewater treatment tank. The fine filter screen structure is located after the coarse filter screen structure. The coarse filter screen structure integrates a fixed horizontal cover and a filter horizontal plate, while the fine filter screen structure integrates a fixed horizontal bar and a filter thin bar. An inlet pipe is provided at the side end of the wastewater treatment tank. An installation groove is formed at the upper end of the wastewater treatment tank. A downstream treatment tank is located at the rear end of the wastewater treatment tank. A first return pipe and a second return pipe are fixedly installed at the lower end of the wastewater treatment tank. A first diversion pipe is fixedly installed at the side end of each fixed horizontal cover. A first control valve is fixedly installed on the inner wall of the mounting groove. Each filter cross plate is arranged in an array at the lower end of the fixed cross cover. A drive shaft is fixedly installed at the upper end of each filter cross plate. The drive shaft is rotatably installed through the inner wall of the fixed cross cover. A drive gear is fixedly installed at the circumferential end of each drive shaft. The same drive toothed belt is sleeved on the outer wall of each drive gear. A motor is fixedly installed on the fixed cross cover. The drive shaft on one side is fixedly installed at the output end of the motor. A spiral tube is fixedly installed on the inner wall of each filter cross plate. A first inlet pipe and a first outlet pipe are fixedly installed at the upper and lower ends of each spiral tube. The first inlet pipe is fixedly installed on the inner wall of the first branch pipe. The end of each first outlet pipe is fixedly installed on the inner wall of the first return pipe.

[0008] Preferably, a second diversion pipe is fixedly installed on the side end of the fixed crossbar, and a second control valve is fixedly installed on the side end of the second diversion pipe. The second control valve is fixedly installed on the inner side wall of the mounting groove.

[0009] Preferably, each of the filter rods is fixedly installed at the lower end of the fixed crossbar, a second inlet pipe is fixedly installed between the filter rod and the second diverter pipe, and a second outlet pipe is fixedly installed between the filter rod and the second return pipe.

[0010] Compared with the prior art, the present invention has the following beneficial effects: In this invention, a coarse filter grid structure and a fine filter grid structure are used in combination to integrate the filtration and water heating functions into the same grid unit. While the wastewater flows through the grid gaps and completes the filtration of impurities, the water is heated by the temperature of the grid elements themselves, eliminating the need for a separate heating unit. For the pretreatment stage of starch wastewater treatment, this integrated structure allows the wastewater to simultaneously complete heat exchange and temperature rise while completing impurity interception, without adding extra steps or residence time to the wastewater treatment process. The treatment efficiency of the pretreatment stage remains consistent with that of a pure filtration grid. Furthermore, all wastewater flowing through the grid can uniformly contact the heated grid wall, preventing some wastewater from entering subsequent units without sufficient heating, thus ensuring the efficiency and continuity of wastewater treatment.

[0011] In this invention, a two-stage heating structure with coarse and fine filter screens is used to heat wastewater using a gradient heating method. The coarse filtration stage completes the initial heating, and the fine filtration stage completes the secondary heating. Considering the characteristic of starch-containing wastewater containing a large number of starch particles, the gradient heating allows the water temperature to rise steadily in stages, avoiding localized high temperatures caused by rapid heating in a single cycle. The water temperature is controlled below the starch gelatinization temperature throughout the process, preventing starch particles from gelatinizing due to localized overheating and forming sticky colloids that are difficult to settle and easily adhere to, thus avoiding clogging of the treatment elements in subsequent sedimentation and biological treatment tanks. Simultaneously, the two-stage heating eliminates temperature stratification within the water body, ensuring a uniform overall temperature of the wastewater entering the subsequent sedimentation and biological treatment units, guaranteeing stable sedimentation and biochemical degradation efficiency for all water bodies.

[0012] In this invention, a heated grid element with filter plates and filter rods is used to ensure that the temperature of the grid wall is higher than that of the flowing water, forming an extremely thin temperature boundary layer between the grid wall and the water. Addressing the issue of starch particles being highly adhesive and easily adhering to the grid at low temperatures, the temperature boundary layer reduces the viscosity of the water near the wall, weakening the adhesion between the starch particles and the grid wall. This allows a small number of starch particles in contact with the wall to naturally detach with the water flow or gravity, preventing them from accumulating in the grid gaps and causing blockages. The filtration gaps of the grid can remain stable over a long period, and the filtration accuracy and flow rate will not decrease with operating time. Frequent interruptions to the wastewater treatment process for grid cleaning are unnecessary, ensuring a continuous and stable filtration process.

[0013] In this invention, a first control valve and a second control valve are respectively connected to the waste heat pipeline in the workshop. This allows the waste heat generated during starch production to be used as a heating medium to heat the wastewater, eliminating the need for additional heating energy. Given the continuous generation of waste heat during starch production, this structure can directly utilize this waste heat to raise the wastewater temperature, eliminating the need for separate electric or steam heating equipment and avoiding the problems of large temperature fluctuations and poor temperature control accuracy associated with additional heating equipment. Simultaneously, the flow rate of the waste heat medium through the two control valves can be adjusted separately for each stage of the screen, flexibly adjusting the heating power according to the influent water temperature to consistently maintain the effluent water temperature within a suitable range for sedimentation and biochemical processes, adapting to changes in influent water temperature under different seasons and production loads.

[0014] In this invention, a motor, a transmission toothed belt, and filter crossbars are integrated to allow for synchronous adjustment of the angles of all filter crossbars via motor drive, flexibly changing the gap size of the coarse filter screen. Addressing the significant differences in wastewater quality across different production stages in a starch workshop, this structure can quickly adjust the filter gap based on varying water quality conditions, such as large-diameter impurities in the raw material washing stage and small-diameter starch particles in the starch washing stage. This eliminates the need for downtime to disassemble and replace screen elements, and wastewater treatment continues normally during the adjustment process. The large gaps can accommodate wastewater with high impurity content, preventing rapid clogging, while the small gaps enhance the interception of fine particles, ensuring stable impurity interception under different operating conditions. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the wastewater treatment tank of the present invention; Figure 2 This is a schematic diagram of the structure of the first reflux tube of the present invention; Figure 3 This is a schematic diagram of the coarse filter grid structure of the present invention; Figure 4 This is a schematic diagram of the fine filter grid structure of the present invention; Figure 5 This is a schematic diagram of the structure of the filter plate of the present invention; Figure 6 This is a schematic diagram of the structure of the fixed horizontal cover of the present invention; Figure 7 This is a schematic diagram of the spiral tube structure of the present invention; Figure 8 This is a schematic diagram of the structure of the fixed crossbar of the present invention.

[0016] In the diagram, the correspondence between component names and attached drawing numbers is as follows: 1. Wastewater treatment tank; 11. Inlet pipe; 12. Installation groove; 13. Subsequent treatment tank; 2. Coarse filter screen structure; 21. Fixed horizontal cover; 22. First diversion pipe; 23. First control valve; 3. Fine filter screen structure; 4. Filter horizontal plate; 41. First inlet pipe; 42. First outlet pipe; 43. Spiral pipe; 45. Drive shaft; 46. Drive gear; 47. Drive toothed belt; 48. Motor; 49. First return pipe; 5. Fixed horizontal bar; 51. Second diversion pipe; 52. Second control valve; 53. Filter rod; 54. Second inlet pipe; 55. Second outlet pipe; 56. Second return pipe. Detailed Implementation

[0017] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0018] Please see Figure 1 - Figure 8 This invention provides a wastewater treatment device for a starch production workshop, including a wastewater treatment tank 1. The wastewater treatment tank 1 is equipped with a treatment mechanism for filtration of wastewater. The treatment mechanism includes a coarse filter screen structure 2 and a fine filter screen structure 3. Both the coarse filter screen structure 2 and the fine filter screen structure 3 are fixedly installed on the inner wall of the wastewater treatment tank 1. The fine filter screen structure 3 is located after the coarse filter screen structure 2. The coarse filter screen structure 2 integrates a fixed horizontal cover 21 and a filter horizontal plate 4. The fine filter screen structure 3 integrates a fixed horizontal bar 5 and a filter thin bar 53. An inlet pipe 11 is provided at the side end of the wastewater treatment tank 1, and an installation groove 12 is opened at the upper end of the wastewater treatment tank 1. A downstream treatment tank 13 is provided at the rear end of the wastewater treatment tank 1. The wastewater from the wheat starch production workshop is generated from wheat raw materials... The process wastewater generated from the entire process of washing, grinding, starch screening, and slurry purification carries wheat bran fiber, free fine starch particles, soluble plant protein, and sugars. In winter, the influent water temperature is usually low. The wastewater first flows into the internal cavity of the wastewater treatment tank 1 through the inlet pipe 11 set at the side end of the wastewater treatment tank 1. After being adjusted by the flow stabilizing structure built into the inlet pipe 11, the wastewater flows into the internal cavity of the wastewater treatment tank 1 at a uniform speed. The wastewater first flows through the coarse filter screen structure 2 set at the front of the inner wall of the wastewater treatment tank 1, completing the first stage of interception of large particles and preliminary preheating of the water. After the coarse filtration, the wastewater continues to flow to the rear of the wastewater treatment tank 1, flowing through the fine filter screen structure 3 set after the coarse filter screen structure 2, completing the second stage of fine filtration of small impurities and secondary heating of the water. After being filtered and heated by two stages of screens, the wastewater finally flows into the subsequent sedimentation tank, biological treatment tank, and other treatment units through the downstream treatment tank 13 located at the rear end of the wastewater treatment tank 1, where it undergoes further treatment such as starch particle sedimentation and organic matter biochemical degradation. Throughout the treatment process, the coarse filter screen 2 is connected to the low-temperature exhaust gas output of the drying section of the starch production workshop via an external pipe through its first control valve 23. This exhaust gas is low-grade waste heat generated during starch drying, serving as the heating medium for the coarse filtration stage. The fine filter screen 3 is connected to the steam return chamber of the cooking section of the starch production workshop via an external pipe through its second control valve 52. This steam return is condensed waste heat generated during starch cooking, serving as the heating medium for the fine filtration stage. Both stages of heating utilize waste heat resources originally wasted during production, achieving cascaded energy recovery without the need to introduce additional fresh steam or electrical energy for heating. A first return pipe 49 and a second return pipe 56 are fixedly installed at the lower end of the sewage treatment tank 1. A first diversion pipe 22 is fixedly installed at the side end of each fixed horizontal cover 21. A first control valve 23 is fixedly installed at the side end of the first diversion pipe 22. The first control valve 23 is fixedly installed on the inner side wall of the mounting groove 12. Each filter plate 4 is arranged in an array at the lower end of the fixed horizontal cover 21. A drive shaft 45 is fixedly installed at the upper end of each filter plate 4. The drive shaft 45 is rotatably installed inside the fixed horizontal cover 21. Each drive shaft 45 has a drive gear 46 fixedly installed at its circumferential end. The outer wall of each drive gear 46 is fitted with the same drive belt 47. A motor 48 is fixedly installed on the fixed cross cover 21. The drive shaft 45 on one side is fixedly installed at the output end of the motor 48. During the flow of wastewater through the coarse filter screen structure 2, the coarse filter screen structure 2 can flexibly adjust the opening angle of the filter cross plate 4 according to the particle size and content of impurities in the wastewater, thereby adapting to different filtration needs. When the wastewater contains large-diameter particles... Impurities such as wheat bran fiber and free fine starch particles can increase the gap between the filter plates 4 to prevent large particles of impurities from accumulating and clogging the gaps. When the particle size of impurities in the wastewater is small, the gap between the filter plates 4 can be reduced to improve the interception effect of small particles of impurities. The angle adjustment process of the filter plates 4 is as follows: The user starts the motor 48 fixedly installed on the fixed cover 21. The output end of the motor 48 drives the transmission shaft 45 fixedly connected to it to rotate. When the transmission shaft 45 rotates, it drives the transmission gear 46 fixedly installed at its circumferential end to rotate synchronously. The transmission gear 46 drives the transmission gear 46 at the end of all other transmission shafts 45 to rotate synchronously without slippage through the synchronous transmission toothed belt 47 sleeved on its outer side wall. This causes all the transmission shafts 45 arranged in the array at the lower end of the fixed cover 21 to rotate synchronously. Each transmission shaft 45 drives the filter plate 4 fixedly connected to it to rotate synchronously at an angle, thereby achieving uniform adjustment of the gap of all filter plates 4. The adjustment process does not require manual adjustment of each grid element. Each filter plate 4 has a spiral tube 43 fixedly installed on its inner wall. Each spiral tube 43 has a first inlet pipe 41 and a first outlet pipe 42 fixedly installed at its upper and lower ends. The first inlet pipe 41 is fixedly installed on the inner wall of the first branch pipe 22, and the end of each first outlet pipe 42 is fixedly installed on the inner wall of the first return pipe 49. In winter, when the wastewater temperature is low, the coarse filter screen structure 2 simultaneously activates its heating function. The first control valve 23 can automatically adjust the flow of waste heat exhaust gas according to the influent water temperature. The low-temperature exhaust gas generated in the drying section of the starch workshop is transported to the first control valve 23 through a pipeline. After flow regulation, it enters the first diversion pipe 22 fixedly installed at the side end of the fixed horizontal cover 21. After being evenly divided in the first diversion pipe 22, the low-temperature exhaust gas flows into the spiral tube 43 fixedly installed on the inner wall of each filter plate 4 through the first inlet pipe 41 set on each filter plate 4. The low-temperature exhaust gas flows along the spiral channel inside the spiral tube 43, which can prolong the residence time of the heat exchange medium compared with the direct flow channel, and at the same time makes the medium Turbulence is generated inside the material to avoid temperature stratification. The heat carried is evenly transferred through the tube wall of the spiral tube 43 to the filter plate 4 body made of thermally conductive stainless steel, so that the filter plate 4 as a whole maintains a stable temperature. The low-temperature exhaust gas after heat exchange is collected and flows out through the first outlet pipe 42 set at the end of each spiral tube 43, and finally flows into the first return pipe 49 fixedly installed at the lower end of the sewage treatment tank 1. It is then transported back to the air preheating system of the workshop for secondary use through the first return pipe 49. In this process, each filter plate 4 is both a filter element that intercepts large particles of impurities in the sewage and a heat exchange element that heats the sewage flowing through it. When the low-temperature sewage flows through the gap between the filter plates 4, the water directly contacts the heated filter plate 4 wall for heat exchange. There is no additional heat exchange medium layer, and the heat exchange resistance is much lower than that of the indirect heat exchange of the external coil. There are no dead zones for heat exchange. While intercepting large particles of impurities, the water temperature of the sewage can be stably raised, providing a suitable temperature basis for the subsequent treatment process. A second diversion pipe 51 is fixedly installed on the side end of the fixed crossbar 5, and a second control valve 52 is fixedly installed on the side end of the second diversion pipe 51. The second control valve 52 is fixedly installed on the inner side wall of the mounting groove 12. Each filter rod 53 is fixedly installed on the lower end of the fixed crossbar 5. A second inlet pipe 54 is fixedly installed between the filter rod 53 and the second diversion pipe 51, and a second outlet pipe 55 is fixedly installed between the filter rod 53 and the second return pipe 56. The wastewater treated by the coarse filter screen structure 2 continues to flow to the fine filter screen structure 3 for secondary treatment. The filter rods 53 arranged in an array on the fine filter screen structure 3 are thin-walled stainless steel hollow cavity structures. The hollow cavity is equipped with guide ribs to make the heat exchange medium flow evenly. The steam generated by the starch workshop cooking section is returned to the second control valve 52 through a pipeline. The second control valve 52 is... The steam flow rate is automatically adjusted according to the temperature of the effluent after coarse filtration. After flow regulation, the steam enters the second diversion pipe 51 fixedly installed at the side end of the fixed crossbar 5. After being evenly distributed in the second diversion pipe 51, the steam flows into the hollow cavity of each filter rod 53 through the second inlet pipe 54 fixedly installed between each filter rod 53 and the second diversion pipe 51. As the steam flows along the guide ribs in the hollow cavity of the filter rod 53, it evenly transfers heat to the outer wall of the filter rod 53, keeping the filter rod 53 at a stable temperature. The steam condensate after heat exchange is collected and flows out through the second outlet pipe 55 set at the end of each filter rod 53, and finally flows into the second return pipe 56 fixedly installed at the lower end of the sewage treatment tank 1. It is then transported back to the raw material cleaning section of the workshop for recycling as production water through the second return pipe 56.

[0019] Working principle: The first step involves wastewater from the wheat starch production workshop, which is the process drainage generated from the entire process of washing, grinding, starch screening, and slurry purification of wheat raw materials. This wastewater contains a mixture of wheat bran fibers, free fine starch particles, soluble plant proteins, and sugars. In winter, the influent water temperature is typically low. The wastewater first flows through the inlet pipe 11 located at one end of the wastewater treatment tank 1. After being regulated by the flow stabilizing structure built into the inlet pipe 11, the wastewater flows at a uniform speed into the internal cavity of the wastewater treatment tank 1. The wastewater first passes through the coarse filter screen 2 located at the front of the inner wall of the wastewater treatment tank 1, completing the process... The wastewater undergoes the first stage of large particle impurity interception and preliminary water preheating. After coarse filtration, the wastewater continues to flow to the rear of wastewater treatment tank 1, passing through the fine filter structure 3 located after the coarse filter structure 2. This completes the second stage of fine impurity filtration and secondary water heating. After filtration and heating treatment by the two-stage screens, the wastewater finally flows into the subsequent treatment tank 13 located at the rear end of wastewater treatment tank 1, and then into subsequent treatment units such as sedimentation tanks and biological treatment tanks for subsequent starch particle sedimentation and organic matter biochemical degradation treatment. Throughout the process, the coarse filter grid structure 2 is connected to the low-temperature exhaust gas output of the drying section of the starch production workshop via an external pipe through the first control valve 23 installed on it. This exhaust gas is the low-grade waste heat generated during the starch drying process, which is used as the heating medium for the coarse filtration stage. The fine filter grid structure 3 is connected to the steam return chamber of the cooking section of the starch production workshop via an external pipe through the second control valve 52 installed on it. This steam return is the condensed waste heat generated during the starch cooking process, which is used as the heating medium for the fine filtration stage. Both stages of heating use the waste heat resources that were originally wasted during the production process, realizing energy cascade recovery without the need to introduce additional fresh steam or electric energy for heating. This application integrates filtration and water heating functions into a single grid unit by using a coarse filter grid structure 2 and a fine filter grid structure 3 in combination. While wastewater flows through the grid gaps and undergoes impurity filtration, the water is heated by the temperature of the grid elements themselves, eliminating the need for a separate heating unit. For the pretreatment stage of starch wastewater treatment, this integrated structure allows wastewater to simultaneously undergo heat exchange and heating while impurity interception is completed, eliminating the need for a separate "filtration then heating" process. This avoids adding extra steps and residence time to the wastewater treatment process, maintaining the same treatment efficiency as a pure filter grid. Furthermore, all wastewater flowing through the grid can uniformly contact the heated grid wall, preventing unheated wastewater from entering subsequent units and ensuring the efficiency and continuity of wastewater treatment. This application employs a two-stage heating structure, consisting of a coarse filter screen 2 and a fine filter screen 3, to heat wastewater using a gradient heating method. The coarse filtration stage provides initial heating, while the fine filtration stage provides secondary heating. Given that starch-rich wastewater contains a large number of starch particles, the gradient heating allows the water temperature to rise steadily in stages, avoiding localized high temperatures caused by rapid heating in a single cycle. The water temperature is maintained below the starch gelatinization temperature throughout the process, preventing starch particles from gelatinizing due to localized overheating and forming sticky colloids that are difficult to settle and easily adhere to, thus avoiding clogging of subsequent sedimentation and biological treatment components. Simultaneously, the two-stage heating eliminates temperature stratification within the water body, ensuring a uniform overall temperature of the wastewater entering the subsequent sedimentation and biological treatment units, guaranteeing stable sedimentation and biodegradation efficiency across all water bodies.

[0020] The second step involves the coarse filter screen structure 2, where the opening and closing angle of the filter plates 4 can be flexibly adjusted according to the particle size and content of impurities in the wastewater to adapt to different filtration needs. When the wastewater contains a high content of large-particle impurities such as wheat bran fiber, the gap between the filter plates 4 can be increased to prevent large particles from accumulating and clogging the screen gaps. When the impurities in the wastewater are small, the gap between the filter plates 4 can be decreased to improve the interception effect of small particles. The angle adjustment process of the filter plates 4 is as follows: the user starts the motor 48 fixedly installed on the fixed cover 21. The output end of the motor 48 drives the transmission shaft 45 fixedly connected to it to rotate. When the transmission shaft 45 rotates, it drives the transmission gear 46 fixedly installed at its circumferential end to rotate synchronously. The transmission gear 46 drives the transmission gears 46 at the ends of all other transmission shafts 45 to rotate synchronously without slippage through the synchronous transmission belt 47 sleeved on its outer wall. The rotation causes the drive shafts 45 of all arrays located at the lower end of the fixed horizontal cover 21 to rotate synchronously. Each drive shaft 45 drives the filter horizontal plate 4 fixedly connected to it to rotate synchronously, thereby achieving uniform adjustment of the gap of all filter horizontal plates 4. The adjustment process does not require manual adjustment of each grid element. The deflection angle of all filter horizontal plates 4 is completely consistent, avoiding local leakage or blockage caused by uneven gaps. In the case of low sewage water temperature in winter, the coarse filter grid structure 2 synchronously starts the heating function. The first control valve 23 can automatically adjust the flow rate of waste heat exhaust gas according to the influent water temperature. The low temperature exhaust gas generated in the drying section of the starch workshop is transported to the first control valve 23 through the pipeline. After the flow rate is adjusted, it enters the first diversion pipe 22 fixedly installed at the side end of the fixed horizontal cover 21. After the low temperature exhaust gas is evenly divided in the first diversion pipe 22, it flows into the spiral pipe 43 fixedly installed on the inner wall of the filter horizontal plate 4 through the first inlet pipe 41 set on each filter horizontal plate 4.The low-temperature exhaust gas flows along the spiral channel inside the spiral tube 43, which prolongs the residence time of the heat exchange medium compared to a direct flow path. It also creates turbulence within the medium, preventing temperature stratification and evenly transferring the heat carried by the exhaust gas through the tube wall of the spiral tube 43 to the filter plate 4 body made of thermally conductive stainless steel. This ensures that the filter plate 4 maintains a stable temperature overall. After heat exchange, the low-temperature exhaust gas is collected and flows out through the first outlet pipe 42 at the end of each spiral tube 43, ultimately flowing into the first return pipe 49 fixedly installed at the lower end of the wastewater treatment tank 1, and is then transported back to the workshop through the first return pipe 49. The air preheating system is reused. In this process, each filter plate 4 is both a filter element that intercepts large particles of impurities in the sewage and a heat exchange element that heats the sewage flowing through it. When the low-temperature sewage flows through the gap between the filter plates 4, the water directly contacts the wall of the filter plate 4 which is heated, and there is no additional heat exchange medium layer. The heat exchange resistance is much lower than that of the indirect heat exchange of the external coil. There are no heat exchange dead zones. While intercepting large particles of impurities, the water temperature of the sewage can be stably increased, providing a suitable temperature basis for the subsequent treatment process. This application utilizes a motor 48, a transmission toothed belt 47, and filter crossplates 4 in coordination. The motor 48 drives the synchronous adjustment of the angles of all filter crossplates 4, flexibly changing the gap size of the coarse filter screen. Addressing the significant differences in wastewater quality across different production stages in a starch workshop, this structure can quickly adjust the filter gap based on varying water quality conditions, such as large-diameter impurities in the raw material washing stage and small-diameter starch particles in the starch washing stage. This eliminates the need for downtime to disassemble and replace screen elements, and wastewater treatment continues normally during the adjustment process. The large gaps can accommodate wastewater with high impurity content, preventing rapid clogging, while the small gaps enhance the interception of fine particles, ensuring stable impurity interception under different operating conditions.

[0021] In the third step, the wastewater treated by the coarse filter screen structure 2 continues to flow to the fine filter screen structure 3 for secondary treatment. The filter rods 53 arrayed on the fine filter screen structure 3 are thin-walled stainless steel hollow cavity structures with guide ribs inside to ensure uniform flow of the heat exchange medium. The steam generated in the starch workshop's cooking section is returned to the second control valve 52 through a pipeline. The second control valve 52 automatically adjusts the steam flow rate according to the temperature of the effluent after coarse filtration. After flow regulation, the steam enters the second diversion pipe 51 fixedly installed at the side end of the fixed crossbar 5. After being evenly distributed in the second diversion pipe 51, the steam flows through each A second inlet pipe 54 is fixedly installed between the filter rod 53 and the second diversion pipe 51, flowing into the hollow cavity of each filter rod 53. As the steam flows along the guide ribs in the hollow cavity of the filter rod 53, it evenly transfers heat to the outer wall of the filter rod 53, keeping the filter rod 53 at a stable temperature. The steam condensate after heat exchange is collected and flows out through the second outlet pipe 55 set at the end of each filter rod 53, and finally flows into the second return pipe 56 fixedly installed at the lower end of the sewage treatment tank 1. It is then transported back to the raw material cleaning section of the workshop through the second return pipe 56 for recycling as production water. Because the gaps between the filter rods 53 are smaller than those between the filter plates 4 in the coarse filtration stage, the wastewater after coarse filtration can be finely filtered a second time to intercept small starch particles and protein colloidal impurities that were not intercepted by the coarse filter grid structure 2. The removal rate of suspended solids in the wastewater is high after two-stage filtration. At the same time, the wastewater is heated a second time by utilizing the wall temperature of the filter rods 53. After two-stage gradient heating, the water temperature of the wastewater gradually and steadily increases to reach the optimal temperature for starch particle sedimentation, which is also the suitable activity temperature for biochemical treatment microorganisms. Gradient heating avoids the problem of gelatinization of a small number of starch particles caused by excessively high single heating temperature. At the same time, the two-stage heating process can make the temperature distribution of the water more uniform and prevent local water temperatures from being too high or too low. During the process of sewage flowing through the two-stage screen, the temperature difference between the screen wall and the water can create a slight turbulence effect in the flowing water, which promotes the collision and aggregation of fine starch particles in the sewage, forming particle clusters of a certain size. The settling speed is increased compared to the original fine particles, which facilitates the sedimentation and interception of starch particles in the subsequent sedimentation tank. The settling time in the subsequent sedimentation tank can be shortened, effectively reducing the load on the subsequent treatment unit. This application utilizes a heated grid element consisting of a filter plate 4 and a filter rod 53 to ensure that the temperature of the grid wall is higher than that of the flowing water, forming an extremely thin temperature boundary layer between the grid wall and the water. Addressing the issue of starch particles being highly adhesive and easily adhering to the grid at low temperatures, the temperature boundary layer reduces the viscosity of the water near the wall, weakening the adhesion between the starch particles and the grid wall. This allows a small number of starch particles in contact with the wall to naturally detach with the water flow or gravity, preventing them from accumulating in the grid gaps and forming blockages. The filtration gaps of the grid can remain stable over a long period, and the filtration accuracy and flow rate will not decrease with operating time. Frequent interruptions to the wastewater treatment process for grid cleaning are unnecessary, ensuring a continuous and stable filtration process. This application utilizes a first control valve 23 and a second control valve 52, respectively connected to the waste heat pipeline in the workshop, to heat wastewater using the waste heat generated during starch production as a heating medium, eliminating the need for additional heating energy. Given the continuous generation of waste heat during starch production, this structure can directly utilize this waste heat to raise the wastewater temperature, eliminating the need for separate electric or steam heating equipment and avoiding the problems of large temperature fluctuations and poor temperature control accuracy associated with additional heating equipment. Simultaneously, the flow rate of the waste heat medium through the two control valves can be adjusted to regulate the two-stage screens, flexibly adjusting the heating power according to the influent water temperature, ensuring the effluent water temperature remains stable within a suitable range for sedimentation and biochemical processes, adapting to changes in influent water temperature under different seasons and production loads.

[0022] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A wastewater treatment device for a starch production workshop, comprising a wastewater treatment tank (1), characterized in that: The sewage treatment tank (1) is equipped with a treatment mechanism that facilitates the filtration of sewage; The treatment mechanism includes a coarse filter screen structure (2) and a fine filter screen structure (3). Both the coarse filter screen structure (2) and the fine filter screen structure (3) are fixedly installed on the inner wall of the sewage treatment tank (1). The fine filter screen structure (3) is located behind the coarse filter screen structure (2). The coarse filter screen structure (2) is equipped with a fixed horizontal cover (21) and a filter horizontal plate (4). The fine filter screen structure (3) is equipped with a fixed horizontal bar (5) and a filter thin bar (53).

2. The wastewater treatment device for a starch production workshop as described in claim 1, characterized in that, The sewage treatment tank (1) is provided with an inlet pipe (11) at its side end, and an installation groove (12) is provided at the upper end of the sewage treatment tank (1).

3. The wastewater treatment device for a starch production workshop as described in claim 2, characterized in that, The sewage treatment tank (1) is provided with a downstream treatment tank (13) at its rear end, and a first return pipe (49) and a second return pipe (56) are fixedly installed at the lower end of the sewage treatment tank (1).

4. The wastewater treatment device for a starch production workshop as described in claim 3, characterized in that, Each of the fixed transverse covers (21) is fixedly installed with a first diversion pipe (22) at its side end, and a first control valve (23) is fixedly installed at its side end.

5. The wastewater treatment device for a starch production workshop as described in claim 4, characterized in that, The first control valve (23) is fixedly installed on the inner side wall of the mounting groove (12).

6. The wastewater treatment device for a starch production workshop as described in claim 5, characterized in that, Each of the filter plates (4) is arranged in an array at the lower end of the fixed cover (21), and a drive shaft (45) is fixedly installed at the upper end of each filter plate (4). The drive shaft (45) is rotatably installed through the inner wall of the fixed cover (21).

7. The wastewater treatment device for a starch production workshop as described in claim 6, characterized in that, A transmission gear (46) is fixedly installed at the circumferential end of each of the transmission shafts (45), and the same transmission toothed belt (47) is sleeved on the outer side wall of each of the transmission gears (46). A motor (48) is fixedly installed on the fixed cross cover (21), and the transmission shaft (45) located on one side is fixedly installed at the output end of the motor (48).

8. The wastewater treatment device for a starch production workshop as described in claim 7, characterized in that, Each of the filter cross plates (4) has a spiral tube (43) fixedly installed on its inner sidewall. Each of the spiral tubes (43) has a first inlet pipe (41) and a first outlet pipe (42) fixedly installed at its upper and lower ends. The first inlet pipe (41) is fixedly installed on the inner sidewall of the first branch pipe (22), and the end of each first outlet pipe (42) is fixedly installed on the inner sidewall of the first return pipe (49).

9. The wastewater treatment device for a starch production workshop as described in claim 8, characterized in that, The second diversion pipe (51) is fixedly installed on the side end of the fixed crossbar (5), and the second control valve (52) is fixedly installed on the side end of the second diversion pipe (51). The second control valve (52) is fixedly installed on the inner wall of the mounting groove (12).

10. The wastewater treatment device for a starch production workshop as described in claim 9, characterized in that, Each of the filter rods (53) is fixedly installed at the lower end of the fixed crossbar (5). A second inlet pipe (54) is fixedly installed between the filter rod (53) and the second diversion pipe (51). A second outlet pipe (55) is fixedly installed between the filter rod (53) and the second return pipe (56).

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