WO2024037444A1

WO2024037444A1 - Sludge dewatering system and use thereof

Info

Publication number: WO2024037444A1
Application number: PCT/CN2023/112514
Authority: WO
Inventors: 张辰; 熊建英; 贺骏; 石广甫; 谢太平
Original assignee: 上海市政工程设计研究总院（集团）有限公司
Priority date: 2022-08-15
Filing date: 2023-08-11
Publication date: 2024-02-22
Also published as: CN115304235A

Abstract

The present invention provides a sludge dewatering system and a use thereof. The system comprises a stacked screw dewatering system, a belt type dewatering system and a low-temperature drying system. Sludge discharged from the stacked screw dewatering system enters the belt type dewatering system via a first intermediate buffer tank, sludge discharged from the belt type dewatering system enters the low-temperature drying system via a second intermediate buffer tank, and sludge discharged from the low-temperature drying system enters a dry sludge silo for temporary storage and then is transported externally. The entering sludge can be thickener sludge having a water mass fraction of about 97%-99% or centrifugal dewatered sludge having a water mass fraction of 80%-85%, and a water content of sludge is adjustable, such that the system has the advantages of flexible process, large adjustability, and high adaptability. According to the present invention, the optimal efficient sections of different dewatering systems are combined and utilized, such that the operation flexibility of a sludge treatment apparatus can be remarkably improved, the sludge dewatering efficiency is improved, and the operation energy consumption is reduced.

Description

A sludge dewatering system and its application

This application claims priority from Chinese patent application 202210973220.7 with a filing date of August 15, 2022. This application cites the full text of the above-mentioned Chinese patent application.

Technical field

The invention belongs to the technical field of sludge dehydration treatment, and in particular relates to a sludge reduction system and its application.

Background technique

With the increase of urban sewage discharge and the continuous improvement of sewage treatment rate in my country, the sludge production of urban sewage treatment plants has also gradually increased. From 2014 to 2020, urban domestic sewage discharge increased from 51.03 billion tons to about 55.05 billion tons. Under normal circumstances, a sewage treatment plant can produce 5-8 tons of sludge with a moisture content of 80% when treating 10,000 tons of domestic sewage. Calculated based on a unit output of 6.5 tons, China's domestic sludge production will remain above 35 million tons from 2014 to 2020.

The moisture content of the sludge in the thickening tank of the sewage plant is about 98%, and the moisture content of the sludge produced by the ordinary centrifugal dehydration process is about 80%. Dehydrating sludge to reduce its moisture content is an effective method to reduce sludge volume and increase sludge calorific value.

The stacked screw sludge dehydrator consists of a fixed ring and a moving ring stacked on top of each other, with a spiral shaft running through them to form a filter body. When the stacked screw sludge dehydrator is running, the sludge enters the filter cartridge from the feed port and is pushed by the spiral shaft vanes and moves toward the discharge port. Since the pitch between the spiral shaft vanes gradually decreases, the sludge is The pressure also increases, and dehydration begins under the action of the pressure difference. The filtrate is discharged from the filter gap formed by the fixed ring and the movable ring. At the same time, the filter is cleaned by relying on the self-cleaning function between the fixed plate and the movable plate. The gap prevents clogging, and the mud cake is discharged from the discharge port under the propelling action of the screw shaft after being fully dehydrated.

The belt dehydration system mainly has the following two steps: ① sludge modification - to sludge through the dosing system Add chemicals in the mud modification mixer and react with the sludge evenly to change the physical and chemical properties of the sludge. In the sludge modification mixer, sludge and chemicals are mixed quickly and evenly. The function of the agent is to destroy the cell wall and destabilize the colloid, thereby reducing the water-holding capacity of the sludge and converting the bound water into "destabilized water"; increasing the internal porosity of the sludge is beneficial to the distribution and distribution of the subsequent deep dehydration stage. Dehydration. ② Sludge dehydration - the modified sludge is transported to the belt-type deep dewatering machine. Under the squeezing force of the high-pressure belt machine, the sludge is deeply dehydrated. The sludge after deep dehydration forms 5-10mm porous flake mud. cake, which is much lower than the mud cake thickness (20-30mm) of the high-pressure plate and frame sludge depth dewatering machine.

The low-temperature drying process uses a dehumidification heat pump to use hot air circulation, condensation, dehumidification and drying of the sludge. The dehumidification heat pump serves as the power source of the dryer and does not require the addition of additional heat sources to achieve energy saving purposes. Dehumidification heat pump drying uses a refrigeration system to cool down the humid air from the drying room. It dehumidifies and uses the heat pump principle to recover the latent heat of moisture condensation and heat the air to dry the materials. The dehumidification heat pump is a combination of dehumidification (dehumidification and drying) and heat pump (energy recovery), and the energy is recycled during the drying process.

The above three main processes all have their own optimal dehydration and high-efficiency sections. The present invention organically combines the three processes to improve the efficiency of sludge dewatering and reduce operating costs.

Contents of the invention

The invention provides a sludge dehydration system and its application. The system can realize the organic combination of snail dehydration, belt dehydration, low-temperature drying and dehydration and other technologies, so as to significantly improve the processing efficiency of sludge dehydration and reduce operating costs. .

The technical solution of the present invention is described in detail below.

In order to achieve the purpose of the present invention, a technical solution adopted by the present invention is specifically:

The invention provides a sludge dehydration system, which includes a centrifugal pump, a homogenizing tank, a wet sludge silo, a screw pump, an integrated dosing system, a screw stacking dehydrator, a #1 intermediate buffer bin, a conditioning agent system, and a sludge dewatering system. Conditioning machine, belt dehydrator, 2# intermediate buffer bin, low-temperature drying system and dry sludge silo; the integrated dosing system is connected to the screw stacking dehydrator through a screw pump, and the outlet end of the homogenization tank is connected to the screw pump through a screw pump. The sludge inlet end of the snail stacking dehydrator is connected, and the sludge outlet end of the snail stacking dehydrator is connected to the inlet end of the 1# intermediate buffer bin. The outlet end of the 1# intermediate buffer bin is connected to the sludge inlet end of the sludge conditioner through a screw conveyor. The outlet end of the wet sludge bin is connected to the wet sludge inlet end of the sludge conditioner through a screw pump. The tap water pipeline is connected to the sludge inlet end of the sludge conditioner. The conditioner system is connected. The conditioner outlet of the conditioner system is connected to the conditioner inlet of the sludge conditioner. The sludge outlet of the sludge conditioner is connected to the sludge inlet of the belt dehydrator. The belt dehydrator The sludge outlet end is connected to the sludge inlet end of the 2# intermediate buffer bin through a lifting scraper conveyor, and the sludge outlet end of the 2# intermediate buffer bin is connected to the sludge inlet end of the low-temperature drying system through a screw conveyor. The sludge outlet end of the low-temperature drying system is connected to the sludge inlet end of the dry sludge silo via a lifting scraper conveyor.

A further preferred solution is that the filtrate outlet end of the screw stacking dehydrator, the filtrate outlet end of the belt dehydrator, and the condensed water discharge end of the low-temperature drying system are respectively connected to the sewage well.

A further preferred solution is that the centrifugal pump is a spiral centrifugal pump or an open impeller centrifugal pump.

A further preferred solution is that in the vertical arrangement, the snail stacking dehydrator is arranged on the upper level of the belt dewatering machine workshop, and the discharged material from the snail stacking dehydrator can flow into the 1# intermediate buffer bin by gravity.

A further preferred solution is that the belt dehydrator is equipped with a flushing system and an air compressor system, and the water used in the flushing system is factory recycle water; the air compressor system is mainly used for tensioning and correcting the filter belt; the low-temperature drying The system is equipped with a circulating cooling system, and the cooling water is recycled water from the factory.

A further preferred solution is that the snail stacking dehydrator, belt dehydrator, low-temperature drying system, wet sludge silo, and dry sludge silo are all equipped with sealing covers, and the sealing covers are connected to a negative pressure exhaust device. , perform negative pressure extraction and deodorization.

Further, the present invention provides the application of the above-mentioned sludge dehydration system. Using the above-mentioned sludge dehydration system to process sludge with a water content of 99%-97% includes the following steps:

S1: The sludge from the concentration tank with a water content of 99%-97% enters the homogenization tank, and enters the snail-stacking dehydrator from the outlet end of the homogenization tank through the screw pump; tap water and chemicals enter the snail-stacking dehydrator through the screw pump. , the sludge and chemicals are fully mixed in the mixing box in the snail stacking dehydrator, and the mixed material is pushed and squeezed by the spiral shaft of the snail stacking dehydrator to obtain sludge with a water content of about 80%. Enter the 1# intermediate cache warehouse;

S2: The sludge with a water content of about 80% in the 1# intermediate buffer bin is sent to the Sludge conditioner, the medicament from the conditioner system enters the sludge conditioner. The sludge is mixed with the medicament and then enters the belt dehydrator. It is dehydrated under the squeezing action of the high-pressure belt machine. The sludge from the belt dehydration system is then passed through Lift the scraper conveyor into the 2# intermediate buffer bin;

S3: The sludge from the 2# intermediate buffer bin enters the low-temperature drying system through spiral conveying. The dehumidification heat pump uses hot air circulation, condensation, dehumidification and drying to dry the sludge. After dehydration, the sludge with a certain moisture content is obtained, and then enters the drying system through the lifting scraper conveyor. The sludge is temporarily stored in the silo and then shipped out.

A further preferred solution is to use a spiral centrifugal pump or an open impeller centrifugal pump to transport the sludge from the concentration tank with a water content of 99%-97% into the homogenization tank.

A further preferred solution is to send the filtrate discharged from the snail stacking dehydrator and the belt dehydrator to the sewage well respectively, and to send the condensed water discharged from the low-temperature drying system to the sewage well.

A further preferred solution is that in the low-temperature drying system described in this application, the dehumidification heat pump uses hot air circulation, condensation, dehumidification and drying of the sludge, and the water content of the sludge obtained after dehydration is 50%-10%. The water content of the sludge produced by the belt dehydration system is 68%-72%, which facilitates the cutting and forming of sludge from the low-temperature drying system.

Furthermore, the present invention also provides another application of the above-mentioned sludge dehydration system. Using the above-mentioned sludge dehydration system to process sludge with a water content of 80-85% includes the following steps:

S1: The sludge with a water content of 80-85% enters the wet sludge silo for temporary storage and is transported to the sludge conditioner through the sludge screw pump. It is mixed with the agent from the conditioner system and then enters the belt dehydrator. Dehydration is completed under the squeezing action of the high-pressure belt machine, and the mud produced by the belt dehydration system is transported by the lifting scraper conveyor into the 2# intermediate buffer bin;

S2: The sludge from the 2# intermediate buffer bin enters the low-temperature drying system through a spiral. The dehumidification heat pump uses hot air circulation, condensation, dehumidification and drying to complete the sludge dehydration. After dehydration, the sludge with a certain moisture content is obtained, and then it is upgraded The scraper conveyor enters the dry sludge silo for temporary storage before being transported out.

A further preferred solution is to send the filtrate discharged from the belt dehydrator to the sewage well, and send the condensed water discharged from the low-temperature drying system to the sewage well.

A further preferred solution is that in this application the low-temperature drying system and the dehumidification heat pump dehumidify the sludge Hot air circulation condensation, dehumidification and drying are used, and the water content of the sludge obtained after dehydration is 50%-10%. The water content of the sludge produced by the belt dehydration system is 68%-72%, which facilitates the cutting and forming of sludge from the low-temperature drying system.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The sludge dehydration system provided by the present invention includes a centrifugal pump, a wet sludge silo, a sludge conveying screw pump, an integrated dosing system, a snail stacking dehydrator, a #1 intermediate buffer bin, a conditioning agent system, and a sludge conveying screw pump. Mud conditioner, belt dehydrator, 2# intermediate buffer bin, low temperature drying system and dry sludge silo, etc., organically combine the technologies of stacked snail dehydration, belt dehydration and low temperature drying and dehydration to make them in their respective The high-efficiency section of the process can effectively improve the efficiency of sludge dewatering and reduce operating costs;

(2) The sludge dehydration system provided by the present invention uses a spiral or open impeller centrifugal pump to transport concentrated sludge, which solves the problem of easy blockage during sludge transport;

(3) The sludge dehydration system provided by the present invention, in order to ensure that the three processes are closely connected, is equipped with intermediate cache silos between process sections, which solves the problem of equipment processing capabilities not being well matched during operation;

(4) In the application of the sludge dehydration system provided by the present invention, in order to ensure the favorable operation of the sludge cutting and forming machine in the low-temperature drying process section, the water content of the sludge produced by the belt dehydrator can be preferably controlled to about 70%, which solves the problem The problem of uneven sludge cutting and shaping in the low-temperature drying process section;

(5) The sludge dehydration system provided by the present invention, in order to ensure that the odor of the sludge during the dehydration process can be effectively controlled, includes stacked snail dehydrators, belt dehydrators, low-temperature drying systems, sludge silos and other equipment. The use of negative pressure extraction after covering or sealing solves the problem of odor leakage during sludge treatment;

(6) The sludge dehydration system and its application provided by the present invention can effectively treat municipal sludge. Compared with the traditional single sludge dehydration method, the present invention can significantly improve the operational flexibility of the system and enhance the future impact of the process system. Adaptability to mud moisture content.

Description of drawings

Figure 1 is a schematic diagram of a sludge dehydration system according to an embodiment of the present invention.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Example

See a sludge dehydration system shown in Figure 1, which includes a centrifugal pump, a homogenizing tank, a wet sludge silo, a screw pump, an integrated dosing system, a snail stacking dehydrator, a #1 intermediate buffer bin, and a conditioning agent system, sludge conditioner, belt dehydrator, 2# intermediate buffer bin, low-temperature drying system and dry sludge silo, etc.

The integrated dosing system is connected to the snail stacking dehydrator via a screw pump. The outlet end of the homogenization tank is connected to the sludge inlet end of the snail stacking dehydrator via a screw pump. The sludge outlet end of the snail stacking dehydrator is connected to the 1# intermediate buffer. The inlet end of the silo is connected, the outlet end of the 1# intermediate buffer silo is connected to the sludge inlet end of the sludge conditioner through a screw conveyor, and the outlet end of the wet sludge silo is connected to the wet sludge inlet end of the sludge conditioner through a screw pump. Connection, the tap water pipeline is connected to the conditioner system, the conditioner outlet end of the conditioner system is connected to the conditioner inlet end of the sludge conditioner, and the sludge outlet end of the sludge conditioner is connected to the sludge inlet end of the belt dehydrator. , the sludge outlet end of the belt dehydrator is connected to the sludge inlet end of the 2# intermediate buffer bin through a lifting scraper conveyor, and the sludge outlet end of the 2# intermediate buffer bin is connected to the sludge inlet of the low-temperature drying system through a screw conveyor. The sludge inlet end of the low-temperature drying system is connected to the sludge inlet end of the dry sludge silo through the lifting scraper conveyor; the filtrate outlet end of the stacked screw dehydrator and the filtrate outlet end of the belt dehydrator , and the condensed water discharge end of the low-temperature drying system are connected to the sewage well respectively.

The sludge dehydration system is arranged vertically, and the snail stacking dehydrator is arranged in the upper workshop of the belt dehydrator. The belt dehydrator is equipped with a flushing system, and the water used in the flushing system is recycled water from the factory. The low-temperature drying system is equipped with a circulating cooling system, and the cooling water is recycled water from the factory area. The snail stacking dehydrator, belt dehydrator, low-temperature drying system, wet sludge silo, and dry sludge silo are all equipped with negative pressure air sealing covers, which can perform negative pressure air extraction and deodorization. The cache volumes of the 1# intermediate cache bin and 2# intermediate cache bin are designed to effectively connect with the subsequent processing system.

Application 1. The sludge dehydration system of the present invention is used to treat sludge with a water content of 98%, including the following steps:

S1: Spiral dehydration system: The sludge from the concentration tank with a water content of about 98% enters the homogenization tank through a spiral centrifugal pump or an open impeller centrifugal pump, and enters the screw pump from the outlet end of the homogenization tank through a screw pump. Dehydrator; tap water and chemicals (PAM, mass concentration 0.1%, dosage mass fraction 3‰~5‰,) enter the snail-stacking dehydrator through the screw pump, and the sludge and reagents are in the mixing box in the snail-stacking dehydrator. After thorough mixing, the mixed material is pushed and squeezed by the spiral shaft and blade of the screw stacking dehydrator to obtain sludge with a water content of about 80%, and enters the 1# intermediate buffer bin. Send the filtrate discharged from the snail stacking dehydrator to the sewage well respectively.

S2: Belt dehydration system: The sludge with a water content of about 80% in the 1# intermediate buffer bin is sent to the sludge conditioner via a screw conveyor. The chemicals (combined salts, mass concentration 20) from the conditioner system %-30%, the dosage mass fraction is 1.5%) and enters the sludge conditioner through the diaphragm metering pump. After the sludge is mixed with the chemicals, it enters the belt dehydrator and is dehydrated under the squeezing action of the high-pressure belt machine. After dehydration The water content of the sludge is about 70%, and it enters the 2# intermediate buffer bin via the lifting scraper conveyor. Send the filtrate discharged from the belt dehydrator to the sewage well.

S3: Low-temperature drying and dehydration system: The sludge with a water content of 70% in the 2# intermediate buffer bin is transported by the spiral into the low-temperature drying system. The dehumidification heat pump uses hot air circulation, condensation, dehumidification and drying for the sludge (the standard drying return air temperature is 45~56℃, air supply temperature is 60~75℃), after dehydration, the sludge with a water content of about 50% (the moisture content of the sludge is adjustable) is obtained, and then enters the dry sludge material through the lifting scraper conveyor Temporarily stored in warehouse and shipped out later. Send the condensed water discharged from the low-temperature drying system to the sewage well.

Application 2. Use the sludge dehydration system of the present invention to treat sludge with a water content of 80% to 85%, including the following steps:

S1: Belt dehydration system: sludge with a water content of 80% to 85% enters the wet sludge silo for temporary storage and is then transported to the sludge conditioner and the agent (combined salt) from the conditioner system through the sludge screw pump. Class, mass concentration 20%-30%, dosage mass fraction 1.5%) is mixed and enters the belt dehydrator. Dehydration is completed under the squeezing action of the high-pressure belt machine. The moisture content of the dehydrated sludge is about 70 %about, Then it is transported by the lifting scraper conveyor into the 2# intermediate buffer bin. Send the filtrate discharged from the belt dehydrator to the sewage well.

S2: Low-temperature drying and dehydration system: The sludge with a water content of 70% from the 2# intermediate buffer bin enters the low-temperature drying system through a spiral. The dehumidification heat pump uses hot air circulation, condensation, dehumidification and drying for the sludge (the standard drying return air temperature is 45～56℃, supply air temperature is 60～75℃) to complete sludge dehydration. After dehydration, the sludge with a water content of 50% (the moisture content of the sludge is adjustable) is obtained, and then enters the dry sludge silo for temporary storage via a lifting scraper conveyor before being transported outside. Send the condensed water discharged from the low-temperature drying system to the sewage well.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above. Those skilled in the art can make various variations or modifications within the scope of the claims, which does not affect the essence of the present invention.

Claims

A sludge dehydration system, which is characterized by including a centrifugal pump, a homogenizing tank, a wet sludge silo, a screw pump, an integrated dosing system, a snail stacking dehydrator, a #1 intermediate buffer bin, a conditioning agent system, and a sludge dewatering system. Sludge conditioner, belt dehydrator, 2# intermediate buffer bin, low-temperature drying system and dry sludge silo; the integrated dosing system is connected to the spiral screw dehydrator via a screw pump, and the sludge outlet end of the concentration tank is connected to a centrifugal pump It is connected to the inlet end of the homogenization pool. The outlet end of the homogenization pool is connected to the sludge inlet end of the snail stacking dehydrator through the screw pump. The sludge outlet end of the snail stacking dehydrator is connected to the inlet end of the 1# intermediate buffer bin. 1# The outlet end of the intermediate buffer bin is connected to the sludge inlet end of the sludge conditioner through a screw conveyor. The outlet end of the wet sludge bin is connected to the wet sludge inlet end of the sludge conditioner through a screw pump. The tap water pipeline is connected to the conditioner. System connection, the conditioner outlet of the conditioner system is connected to the conditioner inlet of the sludge conditioner, the sludge outlet of the sludge conditioner is connected to the sludge inlet of the belt dehydrator, and the sludge inlet of the belt dehydrator is connected. The sludge outlet end is connected to the sludge inlet end of the 2# intermediate buffer bin through a lifting scraper conveyor. The sludge outlet end of the 2# intermediate buffer bin is connected to the sludge inlet end of the low-temperature drying system through a screw conveyor. The low-temperature drying system The sludge outlet end of the chemical system is connected to the sludge inlet end of the dry sludge silo via a lifting scraper conveyor.
The sludge dehydration system according to claim 1, characterized in that the filtrate outlet end of the snail stacking dehydrator, the filtrate outlet end of the belt dehydrator, and the condensed water discharge end of the low-temperature drying system are respectively Connected to the entrance of the sewage well.
The sludge dehydration system according to claim 1 or 2, characterized in that the centrifugal pump is a spiral centrifugal pump or an open impeller centrifugal pump.
The sludge dehydration system according to any one of claims 1 to 3, characterized in that, in a vertical arrangement, the screw stacking dehydrator is arranged on the upper level of the belt dewatering machine workshop.
The sludge dewatering system according to any one of claims 1 to 4, characterized in that the belt dehydrator is equipped with a flushing system and an air compressor system, and the water used in the flushing system is factory recycle water; the low-temperature dryer The chemical system is equipped with a circulating cooling system, and the cooling water source is factory reused water.
The sludge dehydration system according to any one of claims 1 to 5, characterized in that: The snail stacking dehydrator, belt dehydrator, low-temperature drying system, wet sludge silo, and dry sludge silo are all equipped with sealing covers, and the sealing covers are connected to the negative pressure exhaust device.
The application of the sludge dehydration system according to any one of claims 1-6, characterized in that using the sludge dehydration system to process sludge with a water content of 99%-97% includes the following steps:

S1: The sludge from the concentration tank with a water content of 99%-97% enters the homogenization tank, and enters the snail-stacking dehydrator from the outlet end of the homogenization tank through the screw pump; tap water and chemicals enter the snail-stacking dehydrator through the screw pump. , the sludge and chemicals are fully mixed in the mixing box in the snail stacking dehydrator. The mixed materials are pushed and squeezed by the spiral shaft of the snail stacking dehydrator to obtain sludge with a moisture content of about 80%, which enters 1 #Intermediate cache warehouse;

S2: The sludge with a water content of about 80% in the 1# intermediate buffer bin is sent to the sludge conditioner via a screw conveyor. The agent from the conditioner system enters the sludge conditioner, and the sludge is mixed with the agent. The belt dehydrator dehydrates under the squeezing action of the high-pressure belt machine. The mud produced by the belt dehydration system enters the 2# intermediate buffer bin through the lifting scraper conveyor;

S3: The sludge from the 2# intermediate buffer bin enters the low-temperature drying system through spiral conveying. The dehumidification heat pump uses hot air circulation, condensation, dehumidification and drying to dry the sludge. After dehydration, the sludge with a certain moisture content is obtained, and then enters the drying system through the lifting scraper conveyor. The sludge is temporarily stored in the silo and then shipped out.
The application of the sludge dehydration system according to any one of claims 1 to 7, characterized in that using the sludge dehydration system to process sludge with a water content of 80 to 85% includes the following steps:

S1: The sludge with a water content of 80-85% enters the wet sludge silo for temporary storage and is transported to the sludge conditioner through the sludge screw pump. It is mixed with the agent from the conditioner system and then enters the belt dehydrator. Dehydration is completed under the squeezing action of the high-pressure belt machine, and the mud produced by the belt dehydration system is transported by the lifting scraper conveyor into the 2# intermediate buffer bin;

S2: The sludge from the 2# intermediate buffer bin enters the low-temperature drying system through a spiral. The dehumidification heat pump uses hot air circulation, condensation, dehumidification and drying to complete the sludge dehydration. After dehydration, the sludge with a certain moisture content is obtained, and then it is upgraded The scraper conveyor enters the dry sludge silo for temporary storage before being transported out.
The application of the sludge dewatering system according to claim 7, characterized in that the snails are removed from the The filtrate discharged from the water machine and the belt dehydrator is sent to the sewage well respectively, and the condensed water discharged from the low-temperature drying system is sent to the sewage well.
The application of the sludge dehydration system according to claim 8, characterized in that the filtrate discharged from the belt dehydrator is sent to the sewage well, and the condensed water discharged from the low-temperature drying system is sent to the sewage well.
The application of the sludge dehydration system according to claim 7 or 8, characterized in that in the low-temperature drying system, the dehumidification heat pump adopts hot air circulation condensation, dehumidification and drying of the sludge, and the water content mass fraction of the sludge obtained after dehydration is Between 50%-10%.
The application of the sludge dehydration system according to claim 7 or 8, characterized in that the water content of the sludge produced by the belt dehydration system is 68%-72%.