Chemical filtration aiding and mechanical hot-pressing coupling dehydration process and system for treating municipal sludge

Abstract

The invention discloses a chemical filtration aiding and mechanical thermocompression coupling dehydration process and system for treating municipal sludge, and relates to the technical field of sludge dehydration, and the system efficiently treats municipal sludge generated by a sewage treatment plant in a chemical filtration aiding and mechanical thermocompression coupling dehydration mode. Sludge and a medicament are respectively fed into a sewage pretreater through a feeding device and a medicament feeding device, the sewage pretreater is provided with a stirring and uniformly mixing device, the sewage and the medicament are fed into a hot-pressing dehydration device after being fully and uniformly mixed, a steam switch valve is opened, and a dehydration process of chemical filtration aiding and mechanical hot-pressing coupling is carried out; the dehydrated finished product can be used for preparing a high-performance desorption material, and when the removed moisture impurities are excessive, the high-performance desorption material can be discharged after being purified by a wastewater purifier. The water content of the treated municipal sludge can be greatly reduced, reduction and resource utilization of the municipal sludge are realized, and the economic benefit is remarkable.

Description

Technical Field

[0001] The invention relates to the technical field of sludge dehydration, and in particular to a process and system for treating urban sludge by coupling chemical filtration aids with mechanical heat and pressure dehydration. Background Art

[0002] Urban sewage is a general term for sewage discharged into urban sewage systems. Urban sewage mainly includes domestic sewage and industrial sewage, which is generally collected by urban drainage pipes and transported to sewage treatment plants for treatment. Domestic sludge is a regular product of sewage treatment. The sludge discharged from sewage treatment contains a large amount of water. A large amount of water brings many difficulties to the subsequent treatment of sludge, which has always been one of the important issues facing municipal management.

[0003] Sludge dehydration is a high-energy consumption and high-investment process. For this reason, urban sludge in my country has not been effectively treated for a long time. At present, the main methods of sludge dehydration are natural evaporation, mechanical dehydration, evaporation drying and chemical dehydration. The natural evaporation method is to spread the sludge into a thin layer on the sludge drying field. Part of the water contained in the sludge evaporates naturally, and part of it seeps into the soil or filter layer. This method is simple and easy to manage, but it occupies a large area, takes a long time, is greatly affected by the climate, has poor sanitary conditions, and is not effective for some sludge that is not easy to dehydrate. Mechanical dehydration uses mechanical pressure to squeeze out the interstitial water in the sludge. This method has a low dehydration rate and the sludge moisture content is as high as 70% to 80%. The sludge is large in volume and unstable. It is not suitable for direct use and landfill. Incineration is easy to cause secondary pollution and requires secondary dehydration. Evaporation drying dehydration uses heating to evaporate the sludge moisture. This method has a high dehydration rate and the sludge moisture content is below 40%, but it consumes a lot of energy, requires a large investment, occupies a large area, and has high operating costs. Chemical dehydration uses chemicals to destroy the dehydration structure, reduce the affinity between mud and water, and improve the sludge concentration and dehydration performance. This method has a good dehydration effect and the sludge moisture content is below 40%, but the cost of the chemicals is relatively high.

[0004] Therefore, developing low-cost and high-efficiency sludge dewatering methods has become the key to reducing sludge treatment costs and is also a key technical issue in sludge treatment. Summary of the invention

[0005] The purpose of the present invention is to provide a process and system for treating municipal sludge by chemical filtration aid and mechanical heat-pressure coupling dehydration, so as to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above object, the present invention provides a system for treating municipal sludge by chemical filtration aid and mechanical heat-pressure coupling dehydration, comprising:

[0007] A sewage preprocessor, wherein the sewage preprocessor is connected to a medicine feeding device and a material feeding device, a stirring device is arranged inside the sewage preprocessor, and the sewage preprocessor is used to mix the municipal sludge with the medicine;

[0008] The hot-press dehydration device is used to dehydrate the mixed urban sludge and collect the water removed from the urban sludge;

[0009] The steam generating device is used to generate high-temperature and high-pressure steam. The steam generating device is connected to the hot-pressing dehydration device. A steam switching valve is installed on the pipeline between the steam generating device and the hot-pressing dehydration device.

[0010] Preferably, it also includes:

[0011] A wastewater purifier is used to purify the water removed from urban sludge.

[0012] Preferably, the steam generating device is a boiler.

[0013] A process for treating municipal sludge by chemical filtration aid and mechanical heat-pressure coupling dehydration, comprising the following steps:

[0014] a. The municipal sludge and chemical filter aids are put into the sewage pre-treatment device and fully stirred. The mixed municipal sludge is sent to the hot pressure dehydration device, and the hot pressure dehydration device is sealed;

[0015] b. Steam switch valve, which introduces steam into the hot-press dehydration device to heat the municipal sludge to the process temperature. The steam generated by the steam generating device is in direct contact with the municipal sludge for heating. The hot-press dehydration device is used to couple chemical filtration and mechanical hot-pressing dehydration and shaping of the municipal sludge;

[0016] c. De-mould the dehydrated and shaped sludge and send it to the finished product warehouse after cooling.

[0017] Preferably, the method further comprises the following steps:

[0018] d. When the water impurities removed by the hot pressure dehydration device are too much, they are purified by the wastewater purifier before discharge.

[0019] Preferably, the operating temperature of the hot pressing dehydration device is 150-220°C.

[0020] Preferably, the working pressure of the hot pressing dehydration device is 5MPa-12MPa.

[0021] Preferably, the steam introduced into the hot-press dehydration device comes from steam generated by a steam generating device.

[0022] Compared with the prior art, the present invention has the following advantages and technical effects:

[0023] 1. The present invention is suitable for efficient dehydration and recovery of urban sludge. It adopts a dehydration process that couples chemical filtration aids with mechanical heat and pressure, optimizes the product structure, and achieves full recovery of useful components while ensuring the quality of sludge filter cake products;

[0024] 2. The temperature and pressure in the hot-press dehydration device are adjustable, which can better adapt to the fluctuation of the moisture content of the sludge in the sewage treatment plant. When the moisture content is high, the temperature and pressure can be appropriately increased to meet the moisture requirements of the filter cake; when the moisture content is low, the temperature and pressure can be appropriately lowered to ensure the moisture content of the filter cake while reducing energy consumption and achieving maximum recovery of useful components;

[0025] 3. The moisture content of the filter cake after dehydration can be reduced to below 20%, which can reduce the cost of urban sludge treatment and reduce environmental pollution. At the same time, the treated sludge turns waste into treasure. The dried sludge filter cake can be made into high-performance adsorption materials and used as environmental materials in wastewater treatment.

[0026] 4. The addition of wastewater purifier not only ensures the recovery of sludge products, but also avoids polluting the natural water environment;

[0027] 5. The separation process proposed by the present invention is simple, requires little investment, has low operating costs, and has significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is a system diagram of the present invention for treating municipal sludge by chemical filtration aid and mechanical heat-pressure coupling dehydration;

[0030] Figure 2 It is a structural schematic diagram of the hot pressing dehydration device of the present invention;

[0031] In the figure: 1. Sewage pretreatment device; 2. Hot pressure dehydration device; 2-1. Feed inlet; 2-2. Filter plate; 2-3. Filtrate collecting tank; 2-4. Filter cloth; 2-5. Filtrate discharge port; 3. Wastewater purifier; 4. Steam generating device; 5. Steam switch valve; 6. Drug feeding device; 7. Feeding device. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0033] like Figure 1 and 2 As shown, the present invention provides a system for treating municipal sludge by chemical filtration aid and mechanical heat-pressure coupling dehydration, comprising:

[0034] The sewage preprocessor 1 is connected with a medicine feeding device 6 and a material feeding device 7. A stirring device is arranged inside the sewage preprocessor 1. The sewage preprocessor 1 is used to mix the municipal sludge with the medicine;

[0035] The hot-press dehydration device 2 is used to dehydrate the mixed urban sludge and collect the water removed from the urban sludge;

[0036] The steam generating device 4 is used to generate high-temperature and high-pressure steam. The steam generating device 4 is connected to the hot-pressing dehydration device 2 . A steam switching valve 5 is installed on the pipeline between the steam generating device 4 and the hot-pressing dehydration device 2 .

[0037] A further optimized solution is that the hot pressing dehydration device 2 includes a device body, a feed inlet 2-1 is arranged on the top of the device body, a filter plate 2-2 is arranged on the bottom of the device body, a filter cloth 2-4 is arranged on the inner top of the filter plate 2-2, a filtrate discharge port 2-5 is opened on the filter plate 2-2, and a filtrate collecting tank 2-3 is arranged below the filtrate discharge port 2-5.

[0038] Further optimization plans also include:

[0039] The wastewater purifier 3 is used to purify the water removed from the urban sludge.

[0040] To further optimize the solution, the steam generating device 4 adopts a boiler.

[0041] The working process of the present invention is as follows: the municipal sludge and the reagent are respectively sent to the sewage pretreatment device 1 through the feeding device 7 and the reagent feeding device 6. The specific addition ratio of the municipal sludge and the reagent is 400mL of municipal sludge, 2000g / t of cationic surfactant, and 2000g / t of cationic flocculant. The sewage pretreatment device 1 is equipped with a stirring device. After the municipal sludge and the reagent are fully mixed, they enter the hot pressure dehydration device 2 and are sealed. The steam generating device 4 is turned on, the steam switch valve 5 is opened, and steam is introduced into the hot pressure dehydration device 2 to heat the municipal sludge to the process temperature, which is 150-220°C and the pressure is 5MPa-12 MPa, the steam generated by the steam generating device 4 is in direct contact with the municipal sludge for heating, the steam comes from the steam generated by the steam generating device 4, and the municipal sludge is dehydrated and shaped by coupling chemical filtration and mechanical heat pressure; the pressure and temperature can be adjusted, and the dehydration process of coupling chemical filtration and mechanical heat pressure is carried out. The sludge after dehydration and shaping is demolded and sent to the finished product warehouse after cooling. The dehydrated finished product can be used to make high-performance desorption materials. When too much water and impurities are removed, it can be purified by the wastewater purifier 3 and then discharged.

[0042] The above are only preferred specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A system for treating municipal sludge by coupling chemical filtration aids with mechanical heat and pressure dehydration, characterized in that: include: A sewage pretreatment device (1), wherein the sewage pretreatment device (1) is connected to a drug feeding device (6) and a material feeding device (7), a stirring device is provided inside the sewage pretreatment device (1), and the sewage pretreatment device (1) is used to mix urban sludge with the drug; A hot-pressing dehydration device (2) is used to dehydrate the mixed urban sludge and collect the water removed from the urban sludge; A steam generating device (4) is used to generate high-temperature and high-pressure steam. The steam generating device (4) is connected to the hot-pressing dehydration device (2). A steam switching valve (5) is installed on the pipeline between the steam generating device (4) and the hot-pressing dehydration device (2).

2. The system for treating municipal sludge by chemical filtration aid and mechanical heat-pressure coupling dehydration according to claim 1 is characterized in that: Also includes: A wastewater purifier (3) is used to purify the water removed from urban sludge.

3. The system for treating municipal sludge by chemical filtration aid and mechanical heat-pressure coupling dehydration according to claim 1 is characterized in that: The steam generating device (4) is a boiler.

4. A process for treating municipal sludge by coupling chemical filtration aids with mechanical heat and pressure dehydration, characterized in that: The system for treating municipal sludge with chemical filtration aid and mechanical heat-pressure coupled dehydration according to any one of claims 1 to 3 comprises the following steps: a. The municipal sludge and the chemical filter aid enter the sewage pretreatment device (1) and are fully stirred. After stirring and mixing, the municipal sludge is sent to the hot pressure dehydration device (2), and the hot pressure dehydration device (2) is sealed; b. The steam switch valve (5) is used to introduce steam into the hot pressure dehydration device (2) to heat the municipal sludge to the process temperature. The steam generated by the steam generating device (4) is directly in contact with the municipal sludge for heating. The hot pressure dehydration device (2) is used to couple the chemical filtration aid with the mechanical hot pressure to dehydrate and shape the municipal sludge; c. De-mould the dehydrated and shaped sludge and send it to the finished product warehouse after cooling.

5. The process for treating municipal sludge by coupling chemical filtration aid and mechanical heat pressure dehydration according to claim 4, characterized in that: The following steps are also included: d. When the amount of water and impurities removed by the hot pressure dehydration device (2) is too much, the wastewater is purified by the wastewater purifier (3) before being discharged.

6. The process for treating municipal sludge by coupling chemical filtration aid and mechanical heat pressure dehydration according to claim 4, characterized in that: The working temperature of the hot pressing dehydration device (2) is 150-220°C.

7. The process for treating municipal sludge by chemical filtration aid and mechanical heat-pressure coupling dehydration according to claim 4, characterized in that: The working pressure of the hot-pressing dehydration device (2) is 5MPa-12MPa.

8. The process for treating municipal sludge by chemical filtration aid and mechanical heat-pressure coupling dehydration according to claim 4, characterized in that: The steam introduced into the hot pressure dehydration device (2) comes from the steam generated by the steam generating device (4).

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