Sludge high dewatering treatment system combining pressing and low-temperature heat pump drying

Abstract

The utility model discloses a kind of sludge height dewatering treatment systems of pressing and low-temperature heat pump drying association, including sludge conveying system reagent and quantitative conveying system, sludge filter pressing system is respectively communicated with sludge conveying system and reagent quantitative conveying system, for mixed high-wet sludge and reagent and carry out mechanical filter pressing;Low-temperature heat pump sludge drying system cooperates with sludge filter pressing system, for sludge after sludge filter pressing system mechanical filter pressing and further dewatering sludge drying of sludge receiving.The utility model solves the problem that the existing sludge dewatering treatment system lacks the continuous, fast sludge depth dewatering of mechanical pressing and heat drying integrated in one, reduces heat drying energy consumption, uses mechanical filter pressing and low-temperature heat pump sludge drying system combined cooperation, can realize the continuous sludge from water content 80%-87% reduction to 30-40%, meet the requirement of resource treatment.

Description

Technical Field

[0001] This utility model relates to the field of sludge treatment technology, specifically to a sludge high-dehydration treatment system that combines pressing and low-temperature heat pump drying. Background Technology

[0002] With accelerated urbanization and stricter environmental standards, the amount of sludge produced by wastewater treatment plants is increasing year by year. Statistics show that urban wastewater treatment plants in my country produce over 60 million tons of wet sludge annually with a moisture content of around 80%, and the moisture content is generally high (even after traditional treatment, it still reaches 60%-80%). High-moisture sludge not only occupies a large amount of land resources but also easily causes secondary pollution (such as leachate and odor), becoming a key issue restricting the sustainable development of the wastewater treatment industry.

[0003] Current mainstream sludge dewatering technologies include mechanical pressing, thermal drying, and chemical conditioning, but all of them have significant drawbacks: High-pressure extrusion can remove interstitial and capillary water from sludge, reducing the moisture content to 60%-70%, but further reduction is difficult. While this method has low energy consumption, its dewatering efficiency is greatly affected by sludge properties (such as organic matter content and colloidal structure). Thermal drying, which evaporates moisture at high temperatures (100-200℃), can reduce the moisture content to below 10%, but it is extremely energy-intensive, requiring 300-500 kWh of electricity per ton of dried sludge. Therefore, a single technology cannot simultaneously achieve high-efficiency dewatering and low-carbon energy saving, and the moisture content of the treated sludge still cannot meet the requirements for resource utilization.

[0004] Based on the above problems, this application proposes a sludge high-dewatering treatment system that combines pressing and low-temperature heat pump drying. Utility Model Content

[0005] The technical problem to be solved by this utility model is that existing sludge dewatering treatment systems lack continuous and rapid deep sludge dewatering that integrates mechanical pressing and thermal drying, thereby reducing the energy consumption of thermal drying. The purpose is to provide a sludge high-dewatering treatment system that combines pressing and low-temperature heat pump drying.

[0006] This utility model is achieved through the following technical solution: A sludge dewatering system combining pressing and low-temperature heat pump drying, comprising: Sludge conveying system, used to convey high-moisture sludge to be treated and to crush it; A pharmaceutical dispensing system is used to provide and deliver pharmaceuticals. The sludge defiltration system is connected to the sludge conveying system and the reagent metering conveying system, respectively, and is used for mechanical defiltration after mixing sludge and reagents; The low-temperature heat pump sludge drying system, in conjunction with the sludge filter press system, is used to receive sludge after mechanical filtration by the sludge filter press system and further dewater and dry the sludge.

[0007] As one of the preferred technical solutions, a first sludge conveying device, an intermediate silo, a second sludge crusher, and a second sludge conveying device are sequentially arranged between the sludge dewatering system and the low-temperature heat pump sludge drying system.

[0008] As one of the preferred technical solutions, the sludge conveying system includes a wet sludge silo, a first sludge crusher, and a first screw pump. The first sludge crusher is located below the wet sludge silo, and the discharge port of the first sludge crusher is connected to the sludge dewatering system through the first screw pump.

[0009] As one of the preferred technical solutions, the reagent metering delivery system includes a reagent storage tank and a dosing pump. The reagent storage tank is used to store reagents and is connected to the sludge dewatering system. The dosing pump is located between the reagent storage tank and the sludge dewatering system.

[0010] As one of the preferred technical solutions, a ball valve, a flow meter, and a check valve are also provided between the reagent storage tank and the sludge dewatering system.

[0011] As one of the preferred technical solutions, the sludge dewatering system includes a conditioning tank and a sludge dewatering machine. The conditioning tank is connected to a chemical storage tank and a first sludge crusher, respectively. A second screw pump is installed at the discharge port of the conditioning tank and is located above the sludge dewatering machine. A pressing drain pipe is also installed on one side of the sludge dewatering machine.

[0012] As one of the preferred technical solutions, the preparation tank is equipped with a stirring mechanism, and the preparation time of the preparation tank is 1-2 hours.

[0013] As one of the preferred technical solutions, the agent is an aluminum salt, and the dosage of the agent is 3%-10%.

[0014] As one of the preferred technical solutions, the low-temperature heat pump sludge drying system includes a material feeder and a heat pump type low-temperature sludge dryer. The heat pump type low-temperature sludge dryer is equipped with a mesh belt conveyor system and a heat pump system to move the sludge and provide hot dry air. A drain pipe is also provided on one side of the heat pump type low-temperature sludge dryer.

[0015] As one of the preferred technical solutions, the dry hot air is circulating hot air, with a temperature of 45-60℃ and a relative humidity of 8%-12%.

[0016] Compared with the prior art, this utility model has the following advantages and beneficial effects: 1. The present invention provides a sludge high dewatering treatment system that combines pressing and low-temperature heat pump drying. The system uses mechanical filtration and low-temperature heat pump sludge drying system in combination to continuously reduce the moisture content of sludge from 80%-87% to 30-40%, meeting the requirements of resource utilization treatment.

[0017] 2. The sludge dewatering treatment system provided by this utility model, which combines pressing and low-temperature heat pump drying, can further reduce energy consumption and achieve high overall energy efficiency by using mechanical filter pretreatment followed by low-temperature heat pump drying. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model; The attached diagram shows the markings and corresponding component names: 11-Wet sludge silo, 12-First sludge crusher, 13-First screw pump, 14-First sludge conveying equipment, 15-Intermediate silo, 16-Second sludge crusher, 17-Second sludge conveying equipment; 21-Pharmaceutical storage tank, 22-First ball valve, 23-Dosing pump, 24-Second ball valve, 25-Check valve, 26-Flow meter, 27-Pressure drain pipe; 31-Combination tank; 32-Second screw pump; 33-Sludge filter press; 41-Fabricating machine; 42-Heat pump type sludge low-temperature dryer; 43-Dryer drain pipe. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0020] Example 1

[0021] This embodiment 1 provides a sludge high-dewatering treatment system that combines pressing and low-temperature heat pump drying, such as... Figure 1 As shown, It includes a sludge conveying system for transporting and crushing high-moisture sludge to be treated.

[0022] It also includes a reagent metering and delivery system for providing and delivering reagents. The reagent used in this embodiment is an aluminum salt, which can be polyaluminum chloride (PAC) or aluminum sulfate, etc. Its core function is to destroy the colloidal structure of sludge and promote sludge-water separation. After the colloidal structure is destroyed, the adsorbed water and bound water that were originally wrapped inside the particles will be converted into free water that is easier to separate. It can then be efficiently removed by pressing or drying, directly reducing the water content of the sludge.

[0023] It also includes a sludge dewatering system, which is connected to the sludge conveying system and the reagent metering system respectively. It is used to mix high-moisture sludge and reagents. The mixing, conditioning and cell wall breaking time is 1-2 hours to ensure that the colloidal structure is completely destroyed. Then, mechanical dewatering is performed to mechanically press the sludge with a moisture content of 80%-87% to dry sludge with a moisture content of 45-60% after conditioning and cell wall breaking.

[0024] It is also known that the filter cake after the colloid is broken is more likely to meet the requirements of subsequent drying and resource utilization.

[0025] The filter cake after pressing will not form a dense hard shell due to colloid adhesion, but will be in a loose block shape, which is easier to break down later, and has a larger contact area with the drying hot air, thus improving the drying efficiency.

[0026] Finally, it also includes a low-temperature heat pump sludge drying system, which works in conjunction with the sludge filter press system to receive the sludge after mechanical filtration and further dewater and dry it. Ultimately, the sludge with a moisture content of 45%-60% is dried to a moisture content of 30-40% using hot air.

[0027] Furthermore, a first sludge conveying device 14, an intermediate silo 15, a second sludge crusher 16, and a second sludge conveying device 17 are sequentially arranged between the sludge dewatering system and the low-temperature heat pump sludge drying system.

[0028] The first sludge conveying device 14 is located below the sludge dewatering system, the second sludge conveying device 17 is coordinated with the feed inlet of the low-temperature heat pump sludge drying system, the intermediate silo 15 is used to temporarily store sludge, and the second sludge crusher 16 is used to further crush the sludge.

[0029] Specifically, the filter cake after pressure filtration is mostly blocky or plate-shaped with a dense internal structure. Directly entering the drying chamber would severely restrict the drying effect. In this case, a large amount of adsorbed and bound water is trapped inside the dense sludge flocs in the blocky structure. During drying, hot air can only act on the surface, and the internal moisture needs to slowly permeate to the surface to evaporate, resulting in a dry exterior and a wet interior. The filter cake is prone to uneven stacking, and hot air cannot penetrate in thick areas, forming drying dead zones. However, after the crushing step (after crushing by the second sludge crusher 16), the filter cake is dispersed into small particles or strips, and the internal moisture is directly exposed, increasing the contact area with hot air and improving the moisture evaporation rate. In addition, the crushed particles are of uniform size, forming a loose and flat material layer on the conveyor belt. Hot air can penetrate the entire material layer evenly, reducing the final moisture content deviation.

[0030] Example 2

[0031] In the system provided by this utility model, such as Figure 1 As shown, the sludge conveying system includes a wet sludge silo 11, a first sludge crusher 12, and a first screw pump 13. The wet sludge silo 11 is a conventional sludge feeding device used for feeding wet sludge, which has a moisture content of 80%-87%. The first sludge crusher 12 is located below the wet sludge silo 11, so the fed sludge enters the first sludge crusher 12 for crushing. To improve crushing efficiency, in this embodiment, there can be 2-4 first sludge crushers 12. Multiple first sludge crushers 12 can simultaneously crush blocky, plate-like, or highly viscous sludge into small particles or strips with uniform particle size, optimizing the physical morphology of the sludge and preparing it for subsequent dewatering.

[0032] Each first sludge crusher 12 is connected to the sludge dewatering system via a first conveying pipeline, and a first screw pump 13 is installed on the first conveying pipeline at the discharge port of the first sludge crusher 12. That is, the sludge processed by the first sludge crusher 12 flows out from the discharge port, and the first screw pump 13, through the meshing rotation of the screw and the pump sleeve, smoothly and continuously conveys the crushed sludge to the sludge dewatering system.

[0033] Example 3

[0034] In the system provided by this utility model, such as Figure 1 As shown, the reagent metering delivery system includes a reagent storage tank 21 and a dosing pump 23. The reagent storage tank 21 is used to store reagents and is connected to the sludge dewatering system via a second delivery pipeline. The dosing pump 23 is located between the reagent storage tank 21 and the sludge dewatering system. Thus, the dosing pump 23 can accurately and quantitatively add reagents to the sludge dewatering system through the second delivery pipeline.

[0035] Furthermore, a ball valve, a flow meter 26, and a check valve 25 are also installed between the chemical storage tank 21 and the sludge dewatering system. Specifically, there are two ball valves, namely a first ball valve 22 and a second ball valve 24, which are respectively installed on both sides of the dosing pump 23. The check valve 25 and the flow meter 26 are both located on the side of the dosing pump 23 closest to the sludge dewatering system.

[0036] The first ball valve 22 and the second ball valve 24 serve as the main control valves for the pipeline. The ball valves quickly control the on / off flow of the reagent by rotating the valve core (90° opening and closing). For example, the ball valves are opened when the system starts up to allow the reagent to enter the dosing pipeline from the storage tank; the ball valves are closed when the system stops to cut off the reagent supply and prevent the reagent from remaining or leaking in the pipeline.

[0037] The flow meter 26 is an electromagnetic flow meter 26 or a rotor flow meter 26, which can display the instantaneous flow rate and cumulative flow rate of the agent in real time, and intuitively reflect whether the current agent dosage meets the process requirements. In this embodiment, the agent dosage is 3%-10% of the sludge dosage.

[0038] In addition, when the dosing pump 23 stops running, the check valve 25 can prevent residual chemicals in the chemical pipeline from flowing back to the dosing pump 23 or the chemical storage tank 21, thus avoiding negative pressure in the pipeline. There is no need to vent again when starting up next time, ensuring that the dosing pump 23 can quickly enter a stable working state.

[0039] Example 4

[0040] Based on Examples 1-3, such as Figure 1 As shown, in the system provided by this utility model, the sludge dewatering system includes a conditioning tank 31 and a sludge dewatering machine 33. It can be seen that the sludge dewatering system is divided into a mixing and conditioning step and a mechanical dewatering step. The conditioning tank 31 is connected to the chemical storage tank 21 and the first sludge crusher 12, so that the crushed sludge and the chemical enter the conditioning tank 31 together. The conditioning tank 31 is equipped with a stirring mechanism to evenly mix the chemical and sludge to accelerate the sludge cell wall breaking. The conditioning time of the conditioning tank 31 is 1-2 hours.

[0041] In addition, the discharge port of the conditioning tank 31 is located above the sludge filter press 33, and a second screw pump 32 is also installed at the bottom of the conditioning tank 31. The second screw pump 32 pressurizes the sludge and puts it into the sludge filter press 33.

[0042] The sludge filter press 33 uses physical pressing force to squeeze out free water and some adsorbed water from the sludge, achieving sludge volume reduction and moisture content reduction. Based on filtration-pressing synergy, it uses filter cloth (or filter plate) to trap sludge solid particles, while simultaneously squeezing out water through external force. It is known that the sludge filter press 33 also has a press drain pipe 27 on one side to discharge water. Finally, the sludge with a moisture content of 80%-87% is conditioned and broken down, then mechanically pressed to a dry sludge with a moisture content of 45-60%.

[0043] Example 5

[0044] In the system provided by this utility model, the low-temperature heat pump sludge drying system includes a material feeder 41 and a heat pump type low-temperature sludge dryer 42. The heat pump type low-temperature sludge dryer 42 is equipped with a mesh belt conveying system and a heat pump system inside, which are used to move the sludge and provide dry hot air.

[0045] In this embodiment, the spreading machine 41 evenly and stably spreads the crushed sludge filter cake onto the bearing surface of the mesh belt conveyor system, ensuring that the sludge is in full contact with the hot air. This directly determines the drying efficiency and uniformity from the material distribution level. The crushed filter cake particles may clump together locally during descent due to their stickiness or size differences. The spreading machine 41 uses a rotating feeding rod and a swinging feeding hopper to break up and flatten the accumulated filter cake.

[0046] In this process, the heat pump system provides dry hot air and dehumidifying cooling capacity. The dry hot air is circulating hot air with a temperature of 45-60℃ and a relative humidity of 8%-12%.

[0047] The heat pump type sludge low-temperature dryer 42 is also equipped with a dryer drain pipe 43 on one side. Finally, water in the circulating air is condensed by the evaporator of the heat pump system and discharged through the dryer drain pipe 43 at its bottom. After the above low-temperature drying, the sludge moisture content is reduced from 45%-60% to 30-40%.

[0048] The specific working process of this utility model is as follows: Before pressing begins, the sludge needs to be conditioned with chemicals. Both the wet sludge and the chemicals need to be buffered and stored before being transported to the conditioning tank 31 for conditioning. The wet sludge transport path is as follows: 80-87% of the sludge from the outside enters the wet sludge silo 11 from the top for temporary storage. The temporarily stored wet sludge flows out from the bottom of the wet sludge silo 11, is crushed by the first sludge crusher 12, and enters the screw pump. The screw pump transports the sludge through pipelines to the top of the conditioning tank 31, where it falls into the conditioning tank 31 and is uniformly mixed with the chemicals transported from the chemical storage tank 21 for a certain period of time. The chemical delivery path is as follows: the chemical is stored in the chemical storage tank 21 and flows out from the bottom of the chemical storage tank 21 under the power of the chemical pump. After passing through the first ball valve, the chemical pump, the check valve 25, the second ball valve, and the flow meter 26, it flows into the conditioning tank 31 to mix and condition the wet sludge. The cell walls of the microorganisms in the wet sludge are destroyed by the chemical, and the water inside the cells enters the sludge, thereby achieving the conditioning of the sludge.

[0049] After conditioning, the wet sludge flows out from the bottom of conditioning tank 31, passes through the screw pump at the bottom, and enters from the top of sludge filter press 33 under the pressure of the screw pump. After the feeding and pressing process, the water in the wet sludge is separated from the sludge during the pressing process. The water flows out from the bottom of sludge filter press 33 and is discharged through the pressing drain pipe 27. The wet sludge is pressed into 45-60% dry sludge. The dry sludge falls from the left and right sides of the sludge filter press 33 into the first sludge conveying device 14 and is temporarily stored in the intermediate silo 15. The 45-60% dry sludge flows out from the bottom of the intermediate silo 15, is crushed by the second sludge crusher 16 and the second sludge conveying device 17, and is conveyed to the hopper above the cloth feeder 41. After being crushed by the cloth feeder, it enters the heat pump type sludge low temperature dryer 42 and is dried by the 45-60℃ circulating hot air generated by the heat pump type sludge low temperature dryer 42. The sludge with a moisture content of 45%-60% is dried to a moisture content of 30-40%. The water in the circulating air is condensed by the evaporator of the heat pump system and discharged through the dryer drain pipe 43 at the bottom.

[0050] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A sludge dewatering system combining pressing and low-temperature heat pump drying, characterized in that, include: Sludge conveying system, used to transport and crush high-moisture sludge to be treated; A pharmaceutical dispensing system is used to provide and deliver pharmaceuticals. The sludge defiltration system is connected to the sludge conveying system and the reagent metering conveying system, respectively, and is used to mix high-moisture sludge and reagents and perform mechanical defiltration. The low-temperature heat pump sludge drying system, in conjunction with the sludge filter press system, is used to receive sludge after mechanical filtration by the sludge filter press system and further dewater and dry the sludge.

2. The sludge dewatering system combining pressing and low-temperature heat pump drying according to claim 1, characterized in that, The sludge dewatering system and the low-temperature heat pump sludge drying system are sequentially connected by a first sludge conveying device, an intermediate silo, a second sludge crusher, and a second sludge conveying device.

3. The sludge dewatering system combining pressing and low-temperature heat pump drying according to claim 1, characterized in that, The sludge conveying system includes a wet sludge silo, a first sludge crusher, and a first screw pump. The first sludge crusher is located below the wet sludge silo, and the discharge port of the first sludge crusher is connected to the sludge dewatering system through the first screw pump.

4. The sludge high-dewatering treatment system combining pressing and low-temperature heat pump drying according to claim 3, characterized in that, The reagent metering delivery system includes a reagent storage tank and a dosing pump. The reagent storage tank is used to store reagents and is connected to the sludge dewatering system. The dosing pump is located between the reagent storage tank and the sludge dewatering system.

5. The sludge dewatering system combining pressing and low-temperature heat pump drying according to claim 4, characterized in that, A ball valve, a flow meter, and a check valve are also installed between the reagent storage tank and the sludge dewatering system.

6. The sludge high-dewatering treatment system combining pressing and low-temperature heat pump drying according to claim 4, characterized in that, The sludge dewatering system includes a conditioning tank and a sludge dewatering machine. The conditioning tank is connected to a chemical storage tank and a first sludge crusher. The discharge port of the conditioning tank is equipped with a second screw pump and is located above the sludge dewatering machine. A pressing drain pipe is also provided on one side of the sludge dewatering machine.

7. The sludge dewatering system combining pressing and low-temperature heat pump drying according to claim 6, characterized in that, The mixing tank is equipped with a stirring mechanism, and the mixing time is 1-2 hours.

8. The sludge high-dewatering treatment system combining pressing and low-temperature heat pump drying according to claim 4, characterized in that, The agent is an aluminum salt, and the dosage of the agent is 3%-10%.

9. The sludge dewatering system combining pressing and low-temperature heat pump drying according to claim 1, characterized in that, The low-temperature heat pump sludge drying system includes a material feeder and a heat pump type low-temperature sludge dryer. The heat pump type low-temperature sludge dryer is equipped with a mesh belt conveyor system and a heat pump system to move the sludge and provide hot dry air. The heat pump type sludge low-temperature dryer is also equipped with a dryer drain pipe on one side.

10. The sludge dewatering system combining pressing and low-temperature heat pump drying according to claim 9, characterized in that, The dry hot air is a circulating hot air with a temperature of 45-60℃ and a relative humidity of 8%-12%.

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