CN116712777A - High-pressure gradient circulation squeezing system and squeezing process - Google Patents

Abstract

The invention provides a high-pressure gradient circulation drying system and a drying process, including a left cloth machine system, a press system and a right cloth machine system. The left cloth machine system and the right cloth machine system have the same structure; The left cloth machine system and the right cloth machine system are arranged symmetrically; the press system consists of a press body, a hydraulic station, a press frame, a horizontal push-pull oil cylinder, a rising oil cylinder and a main oil cylinder. The high-pressure gradient circulation drying system of the present invention does not require any additives in the pressing process, the pressing time is about 30 minutes, normal temperature is enough, and the working pressure is 6-8Mpa; the deep dehydration process does not require auxiliary heat energy, vacuum suction, condensation system and odor adsorption. System, etc.; it can deeply dehydrate the sludge with a moisture content of 85% after initial dehydration in the form of pressing to a moisture content of less than 40% at one time, greatly reducing labor costs.

Description

A high-pressure gradient circulation drying system and drying process

Technical field

The invention belongs to the technical field of filter press dehydration treatment, and in particular relates to a high-pressure gradient circulation drying system and a drying process.

Background technique

With the rapid improvement of my country's sewage treatment capacity, sludge production has increased sharply. Relevant data shows that my country's sludge production will reach 72.883 million tons in 2022. my country's sludge treatment situation is severe, which is bound to bring a new upsurge in industry development, and Promote the improvement of the resource utilization level of sludge and the development of incineration disposal.

Sludge is a solid sedimentary substance produced by water and sewage treatment processes. Since the properties of various types of sludge vary greatly, classification is very necessary, and their treatment and disposal are also different. According to its source, it can be divided into: Municipal sludge, mainly refers to sludge from sewage plants, which is the largest type of sludge. In addition, sludge from water plants also comes from municipal facilities and can be classified into this category; pipe network sludge comes from drainage collection systems; river and lake sludge comes from rivers and lakes; industrial sludge comes from various A mixture of solids and water, oil, chemical pollution, and organic matter produced by industrial production.

In addition, the Chinese patent announcement number is CN104492134B, and the name of the invention is a sludge forced pressure deep dewatering system. The sludge forced pressure deep dehydration system consists of a stroke bracket, a front roof plate, a rear roof plate, a shrinking steel rod, a piston grouting pump, and a discharge It consists of a plate and two or more arranged dewatering units. The system uses a piston grouting pump for forced grouting, which solves the problem of difficulty in feeding sludge with high moisture content; the dehydration unit has a shrinking function, and is driven by a strong hydraulic cylinder to achieve deep dehydration of sludge; the discharge plate shrinks the steel rod In conjunction with the robot, automatic discharge of dewatered sludge is realized.

At present, the mainstream deep dewatering of sludge in the market uses a screw stacker or a decanter to dehydrate the settled sludge in the sewage sedimentation tank to a moisture content of about 85%. Then, the sludge with a moisture content of 85% is dehydrated again to a moisture content of 60% through low-pressure/medium-pressure filtration equipment, and auxiliary equipment such as heat exchange and vacuum systems are equipped to finally reduce the moisture content of the sludge to the owner's needs; these processes have a great impact on energy The consumption is huge and the cost of sludge treatment per ton is expensive.

There are mature technologies such as low-temperature vacuum dehydration for plate and frame filter press, and high-pressure and deep dehydration for single-layer hydraulic systems. However, low-temperature vacuum dehydration technology for plate and frame filter press mainly uses an oil pump to push the pressure plate horizontally to transmit pressure and squeeze multiple layers. After the filter plate reaches a certain time, the sludge is dried with a heat source to a moisture content of 40%-60%. This process requires heat exchange equipment, condensation equipment, vacuum suction equipment, and deodorization equipment in the exhaust section. . The process is complex, the energy consumption is high, and the system requires more supporting personnel.

The single-layer high-pressure deep dehydration technology of the hydraulic system mainly transports sludge to the pressing station through pipelines through feeding equipment. The hydraulic mechanism presses the sludge, and the pressed sludge is transferred through the conveying equipment. This system has a simple process and automatic production line control, but its daily sludge processing efficiency is low and the processing capacity is low. Moreover, the production area is highly polluted and does not meet the needs of ecologically civilized production.

In view of this, it is very necessary to invent a high-pressure gradient circulation drying system and drying process.

Contents of the invention

In order to solve the above technical problems, the present invention provides a high-pressure gradient circulation drying system and drying process, which can deeply dehydrate the sludge with a moisture content of 85% after initial dehydration to a moisture content of less than 40% at one time in the form of pressing. At the same time, this technology effectively reduces the treatment cost per ton of sludge, reduces auxiliary equipment, intelligently controls the system, and reduces labor costs.

A high-pressure gradient circulation drying system, including a left distributor system, a press system and a right distributor system. The left distributor system and the right distributor system have the same structure; the left distributor system The system and the right distributor system are arranged relatively symmetrically; the left distributor system and the right distributor system are located on the left and right sides of the press system respectively; the left distributor system is provided with sludge on the left side The outlet of the sludge bin is provided with a humidifying and stirring device; the outlet of the humidifying and stirring device is provided with a screw pump; the screw pump is connected to the left distributor system.

Preferably, the left distributor system and the right distributor system are composed of a distributor body, a lower motor, a lower filter cloth roller, an upper motor, an upper filter cloth roller, a redirection combination pressure roller and a distributor. The lower motor is bolted to the right side of the distribution machine body; the lower filter cloth roller is bolted to the right side of the distribution machine body and connected to the lower motor; the upper motor is bolted to the left side of the distribution machine body. side and is meshed and connected with the upper filter cloth drum; the reversing combined pressure roller is bolted to the upper left side of the distributor body; the component distributor is bolted to the upper side of the distributor body.

Preferably, the press system is composed of a press body, a hydraulic station, a pressing frame, a horizontal push-pull oil cylinder, a rising oil cylinder and a main oil cylinder. The press body is connected to the hydraulic station through pipelines; the main oil cylinder is connected to the hydraulic station. The oil cylinder is bolted to the upper part of the press body; the press body is bolted to the upper part of the press frame; the horizontal push-pull oil cylinder is set horizontally on the upper left side of the press body; the rising oil cylinder is longitudinally bolted to The lower part of the press body.

Preferably, the left cloth machine system occupies an area of about 6.5x1.6 meters, and the installation height is about 2 meters.

Preferably, the upper motor and upper filter cloth drum and the lower motor and lower filter cloth drum are arranged in upper and lower layers, which can realize multi-layer stacking of sludge between the double layers of filter cloth.

Preferably, a chain plate mechanism is provided inside the lower filter cloth drum.

Preferably, the sludge is spread on the lower filter cloth drum of the distributor through a distributor. The filter cloth of the lower filter cloth drum moves forward following the reciprocating motion of the chain plate mechanism driven by the lower motor. The filter cloth moves forward synchronously with the reversing combination pressure roller driven by the upper motor. Through the pre-adjusted gap between the upper and lower filter cloths of the lower filter cloth roller and the upper filter cloth roller, the deviation correction and flattening devices achieve uniform stacking of sludge. Effect.

Preferably, the press system occupies an area of about 10x4 meters and is installed at a height of about 8 meters from the ground.

Preferably, the sludge is stacked back and forth in the press frame through the left distributor system and the right distributor system, and the press frame is moved to the filter press station by horizontally pushing and pulling the oil cylinder. After the hydraulic station is started, the main drive is The piston rod of the oil cylinder moves downward, thereby driving the pressing platform to press and dehydrate the sludge in the pressing frame; after pressing for a certain period of time, a deeply dehydrated dry mud cake with qualified moisture content is reached.

Preferably, the hydraulic station is opened to drive the main oil cylinder to lift upward to the initial station; the horizontal push-pull oil cylinder moves the press frame body to the transfer station, and the other press frame body also enters the filter press station simultaneously to start pressing and dehydration; the transfer station The sludge mud cake in the press frame is gradually ejected through the rising oil cylinder. During the reciprocating motion of the main body of the distributor, the sludge mud cake is sent to the discharge slot. The mud cake is moved under the action of the reversing pressure roller. , automatically falls off to the discharge chute; the filter cloth after discharge automatically returns to the filter cloth drum. When the dry mud cake is completely shed, the cloth machine automatically restarts cloth distribution.

Preferably, the pressing process of the left distributor system, press system and right distributor system does not require any additives, the pressing time is about 30 minutes, normal temperature is sufficient, and the working pressure is 6-8Mpa.

The invention provides a drying process of a high-pressure gradient circulation drying system, which mainly includes the following steps:

Step 1: Humidification and discharging of sludge bin;

Step 2: Stack the sludge between the double layers of filter cloth in multiple layers;

Step 3: Stacking of reciprocating compressors for sludge;

Step 4: Forming of deeply dehydrated dry mud cake;

Step 5: The dry mud cake is completely peeled off.

Preferably, in step one, the humidification and discharging operation of the sludge bin is mainly to transport the sludge that has been initially dehydrated to 85% moisture content from the upstream to the sludge bin in a sealed manner, and the outlet of the sludge bin is equipped with a humidifier. The stirring device enables the sludge when discharging from the sludge bin to pass through the screw pump evenly and be transported to the distributor system; thereby transporting the sludge with a moisture content of 85% after initial dehydration that needs to be squeezed.

Preferably, in step two, the 85% moisture content sludge in step one is spread on the lower filter cloth drum of the distributor through a distributor, and the filter cloth of the lower filter cloth drum follows the chain plate mechanism driven by the lower motor. The reciprocating motion of the upper filter cloth drum moves forward, and the filter cloth of the upper filter cloth drum moves forward simultaneously with the reversing combined pressure roller driven by the upper motor, passing through the pre-adjusted gap between the upper and lower filter cloths of the lower filter cloth drum and the upper filter cloth drum. Deviation correction and flattening devices achieve the effect of even stacking of sludge.

Preferably, in step three, the sludge in step two is stacked back and forth on the press frame through the left distributor system and the right distributor system, and the press frame is moved to the filter press station by horizontally pushing and pulling the oil cylinder. , after the hydraulic station is started, the piston rod of the main cylinder is driven to move downward, thereby driving the press table to press and dehydrate the sludge in the pressure frame; after pressing for a certain period of time, a deeply dehydrated dry mud cake with qualified moisture content is reached.

Preferably, in step four, the hydraulic station is opened to drive the main oil cylinder to lift upward to the initial station; the horizontal push-pull oil cylinder moves the press frame to the transfer station, and the other press frame also enters the filter press station simultaneously to start. Press and dehydrate.

Preferably, in step five, the sludge cake in the press frame of the transfer station is gradually ejected through the rising oil cylinder. During the reciprocating motion of the main body of the distributor, the sludge cake is sent to the discharge slot. The mud cake automatically falls off to the discharge chute under the action of the reversing pressure roller; the unloaded filter cloth automatically returns to the filter cloth drum, and the dry mud cake falls off after completion; the moisture content of the treated sludge is 40 % or less, the deeply dehydrated dry mud cake is transported to the blanking slot of the steel platform through the chain plate transmission mechanism of the distributor. The mud cake automatically falls to the belt conveyor under the blanking slot through the action of the reversing pressure roller. On the machine, the dry mud is finally transported to the waiting transfer position through the climbing chain plate elevator.

Preferably, the decanter, sludge bin, screw pump, distributor, cleaning machine, pressing tank, press, belt conveyor and sludge used in the drying process of the high-pressure gradient circulation drying system Transfer equipment and other equipment are common application equipment in this technical field, and the specific details will not be repeated here.

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

The high-pressure gradient circulation drying system of the invention does not require any additives during the pressing process. The pressing time is about 30 minutes at room temperature and the working pressure is 6-8Mpa. According to the evaluation, the high-pressure gradient circulating drying system costs less than 50 yuan per ton of sludge treatment and is deeply dehydrated. The process does not require auxiliary heat energy, vacuum suction, condensation system and odor adsorption system. The system is fully automatically controlled. In the production area, each production line only needs one person to monitor the normal operation of the system, which greatly reduces labor costs.

It can deeply dehydrate the sludge with a moisture content of 85% after initial dehydration in the form of pressing to a moisture content of less than 40% at one time; at the same time, this technology effectively reduces the treatment cost per ton of sludge, reduces auxiliary equipment, and intelligently controls the system. Reduce labor cost issues.

Description of the drawings

Figure 1 is a schematic structural diagram of the present invention.

Figure 2 is a schematic structural diagram of the distribution machine system of the present invention.

Figure 3 is a schematic structural diagram of the press system of the present invention.

Figure 4 is a schematic structural diagram of the drying process of the present invention.

Figure 5 is a schematic diagram of the process flow diagram of the drying process of the present invention.

Figure 6 is a graph of test parameters and results of the present invention.

In the picture:

1. Left cloth machine system; 3. Right cloth machine system; 11. Main body of cloth machine; 12. Lower motor; 13. Lower filter cloth roller; 14. Upper motor; 15. Upper filter cloth roller; 16. Change direction Combined press roller; 17. Distributor; 2. Press system; 21. Press main body; 22. Hydraulic station; 23. Press frame; 24. Horizontal push-pull cylinder; 25. Rising cylinder; 26. Main cylinder.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings:

Example:

As shown in Figures 1 to 2, the present invention provides a high-pressure gradient circulation drying system and drying process, including a left distributor system 1, a press system 2 and a right distributor system 3. The left cloth machine system 1 and the right cloth machine system 3 have the same structure; the left cloth machine system 1 and the right cloth machine system 3 are arranged symmetrically; the left cloth machine system 1 and the right cloth machine The system 3 is located on the left and right sides of the press system 2 respectively; the left side of the left distributor system 1 is provided with a sludge bin, and the outlet of the sludge bin is equipped with a humidifying and stirring device; the humidifying and stirring device A screw pump is provided at the outlet; the screw pump is connected to the left distributor system 1.

In the above embodiment, specifically, the left distribution machine system 1 and the right distribution machine system 3 are composed of a distribution machine body 11, a lower motor 12, a lower filter cloth drum 13, an upper motor 14, and an upper filter cloth drum 15. The pressure roller 16 is combined to form a distributor 17. The lower motor 12 is bolted to the right side of the distributor body 11; the lower filter cloth roller 13 is bolted to the right side of the distributor body 11 and is connected to the distributor body 11. The lower motor 12 is connected; the upper motor 14 is bolted to the left side of the distributor body 11 and meshed with the upper filter cloth roller 15; the reversing combined pressure roller 16 is bolted to the distributor body 11 The upper left side of the distribution machine 17 is bolted to the upper side of the distribution machine body 11.

In the above embodiment, specifically, the press system 2 is composed of a press body 21, a hydraulic station 22, a pressing frame 23, a horizontal push-pull cylinder 24, a rising cylinder 25 and a main cylinder 26. The press body 21 is connected to the hydraulic station 22 by pipelines; the main oil cylinder 26 is bolted to the upper part of the press body 21; the press body 21 is bolted to the upper part of the press frame 23; the horizontal push-pull oil cylinder 24 It is arranged horizontally on the upper left side of the press body 21; the rising oil cylinder 25 is longitudinally bolted to the lower part of the press body 21.

In the above embodiment, specifically, the left cloth machine system 1 occupies an area of about 6.5x1.6 meters, and the installation height is about 2 meters.

In the above embodiment, specifically, the upper motor 14 and the upper filter cloth drum 15 and the lower motor 12 and the lower filter cloth drum 13 are arranged in upper and lower layers, which can realize multi-layer stacking of sludge between the double layers of filter cloth.

In the above embodiment, specifically, a chain plate mechanism is provided inside the lower filter cloth drum 13 .

In the above embodiment, specifically, the sludge is spread on the lower filter cloth drum 13 of the distributor through the distributor 7, and the filter cloth of the lower filter cloth drum 13 follows the reciprocating motion of the chain plate mechanism driven by the lower motor 12. Moving forward, the filter cloth of the upper filter cloth drum 15 moves forward simultaneously with the redirection combination pressure roller 16 driven by the upper motor 14, passing through the pre-adjusted lower filter cloth drum 13 and the upper filter cloth drum 15. The upper and lower layers of filter cloth Gap, correction and flattening devices achieve the effect of even stacking of sludge.

In the above embodiment, specifically, the press system 2 occupies an area of about 10x4 meters, and is installed at a height of about 8 meters from the ground.

In the above embodiment, specifically, the sludge is stacked back and forth on the pressing frame 23 through the left distributor system 1 and the right distributor system 3, and the pressing frame 23 is moved to the pressing frame 23 by horizontally pushing and pulling the oil cylinder 24. At the filtering station, after the hydraulic station 22 is started, it drives the piston rod of the main oil cylinder 26 to move downward, thereby driving the press table to press and dehydrate the sludge in the pressure frame 23; after pressing for a certain period of time, the deeply dehydrated dry sludge reaches the qualified moisture content. cake.

In the above embodiment, specifically, the hydraulic station 22 is opened to drive the main oil cylinder 26 to lift upward to the initial station; the horizontal push-pull oil cylinder 24 moves the pressing frame body 23 to the transfer station, and the other pressing frame body 23 also enters simultaneously. The filter press station starts pressing and dehydrating; the sludge cake in the press frame 23 of the transfer station is gradually ejected through the rising oil cylinder 25. During the reciprocating motion of the main body 11 of the distributor, the sludge cake is sent to the unloading station. In the material trough, the mud cake automatically falls off to the discharge chute under the action of the reversing pressure roller; the filter cloth after discharge automatically returns to the filter cloth drum. When the dry mud cake falls off, the distribution machine automatically restarts. cloth.

In the above embodiment, specifically, the pressing process of the left cloth machine system 1, press system 2 and right cloth machine system 3 does not require any additives, the pressing time is about 30 minutes, normal temperature is sufficient, and the working pressure is 6-8Mpa. .

The invention provides a drying process of a high-pressure gradient circulation drying system, which mainly includes the following steps:

Step 1: Humidification and discharging of sludge bin;

Step 2: Stack the sludge between the double layers of filter cloth in multiple layers;

Step 3: Stacking of reciprocating compressors for sludge;

Step 4: Forming of deeply dehydrated dry mud cake;

Step 5: The dry mud cake is completely peeled off.

In the above embodiment, specifically, in step one, the operation of humidifying and discharging the sludge bin is mainly to transport the sludge that has been initially dehydrated to a moisture content of 85% from the upstream to the sludge bin in a sealed manner. The outlet of the bin is equipped with a humidification and stirring device, so that the sludge when discharging from the sludge bin can evenly pass through the screw pump and be transported to the distributor system; thus, the sludge with a moisture content of 85% after initial dehydration that needs to be squeezed can be transported .

In the above embodiment, specifically, in step two, the 85% moisture content sludge in step one is spread on the lower filter cloth drum 13 of the distributor through the distributor 7, and the filter cloth of the lower filter cloth drum 13 is Following the reciprocating motion of the chain plate mechanism driven by the lower motor 12, the filter cloth of the upper filter cloth roller 15 moves forward simultaneously with the redirection combination pressure roller 16 driven by the upper motor 14, passing through the pre-adjusted lower filter cloth. The gap between the upper and lower filter cloths of the drum 13 and the upper filter cloth drum 15, as well as the deviation correction and flattening devices, achieve the effect of even stacking of sludge.

In the above embodiment, specifically, in step three, the sludge in step two is reciprocally stacked on the pressing frame 23 through the left distributor system 1 and the right distributor system 3, and the oil cylinder 24 is pushed and pulled horizontally. The press frame 23 moves to the filter press station. After the hydraulic station 22 is started, it drives the piston rod of the main oil cylinder 26 to move downward, thereby driving the press table to press and dehydrate the sludge in the press frame 23; after pressing for a certain period of time, the qualified water content is reached. Rate of deep dehydration dry mud mud cake.

In the above embodiment, specifically, in step four, the hydraulic station 22 is opened to drive the main oil cylinder 26 to lift upward to the initial station; the horizontal push-pull oil cylinder 24 moves the pressing frame body 23 to the transfer station, and the other pressing frame Body 23 also enters the filter press station simultaneously to start pressing and dewatering.

In the above embodiment, specifically, in step five, the sludge cake in the pressing frame 23 of the transfer station is gradually ejected through the rising oil cylinder 25. During the reciprocating movement of the distributor body 11, the sludge cake will be The sludge is sent to the discharge chute, and the mud cake automatically falls off to the discharge chute under the action of the reversing pressure roller; the unloaded filter cloth automatically returns to the filter cloth drum until the dry mud cake falls off; The moisture content of the treated sludge is below 40%. The deeply dehydrated dry sludge cake is transported to the dropping slot of the steel platform through the chain plate transmission mechanism of the distributor. The mud cake falls automatically through the action of the reversing pressure roller. On the belt conveyor under the blanking slot, the dry mud is finally transported to the waiting transfer position through the climbing chain plate elevator.

In the above embodiment, specifically, the decanter, sludge bin, screw pump, distributor, cleaning machine, pressing tank, press, and belt used in the drying process of the high-pressure gradient circulation drying system Equipment such as conveyors and sludge transfer are common application equipment in this technical field, and the details will not be described here.

The invention's high-pressure gradient circulation drying system and drying process have initially achieved the expected results after testing on the test platform. Within 30 minutes, the 85% moisture content sludge after multi-layer stacking can be directly pressed to a moisture content of less than 40% in one go. . Sludge with a moisture content of 85% and dry sludge with a moisture content of 40% after deep dehydration have been tested repeatedly with professional instruments. Examples of test parameters and results are shown in Figure 6.

The test parameter statistics are shown in Table 1 below:

Table 1

In summary, the sludge with a moisture content of 85% after initial dehydration can be deeply dehydrated in the form of pressing to a moisture content of less than 40% at one time; at the same time, this technology effectively reduces the treatment cost per ton of sludge and reduces auxiliary equipment. Intelligent system control reduces labor costs.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " The directions indicated by "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" etc. or The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation of the present invention.

Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it is still The technical solutions described in the foregoing embodiments may be modified, or some of the technical features may be equivalently replaced. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. A high-pressure gradient circulation drying system and drying process, characterized in that the high-pressure gradient circulation drying system includes a left distributor system (1), a press system (2) and a right distributor system ( 3), the left cloth machine system (1) and the right cloth machine system (3) have the same structure; the left cloth machine system (1) and the right cloth machine system (3) are arranged symmetrically; The left cloth machine system (1) and the right cloth machine system (3) are respectively located on the left and right sides of the press system (2); the left side of the left cloth machine system (1) is provided with a dirt Mud bin, the outlet of the sludge bin is provided with a humidifying and stirring device; the outlet of the humidifying and stirring device is provided with a screw pump; the screw pump is connected to the left distributor system (1). 2. The high-pressure gradient circulation drying system according to claim 1, characterized in that the left distributor system (1) and the right distributor system (3) consist of a distributor main body (11) and a lower motor. (12), the lower filter cloth roller (13), the upper motor (14), the upper filter cloth roller (15), the redirection combined pressure roller (16) and the composition distributor (17), the lower motor (12) Bolts are connected to the right side of the distribution machine body (11); the lower filter cloth roller (13) is bolted to the right side of the distribution machine body (11) and connected to the lower motor (12); the upper The motor (14) is bolted to the left side of the main body of the distribution machine (11) and is engaged and connected with the upper filter cloth roller (15); the reversing combination pressure roller (16) is bolted to the main body of the distribution machine (11) The upper left side of the distribution machine (17) is bolted to the upper side of the distribution machine body (11). 3. The high-pressure gradient circulation drying system according to claim 1, characterized in that the press system (2) consists of a press body (21), a hydraulic station (22), and a press frame (23). It consists of a horizontal push-pull oil cylinder (24), a rising oil cylinder (25) and a main oil cylinder (26). The main body of the press (21) is connected to the hydraulic station (22) by pipelines; the main oil cylinder (26) is bolted On the upper part of the press body (21); the press body (21) is bolted to the upper part of the press frame (23); the horizontal push-pull oil cylinder (24) is horizontally arranged on the press body (21) Upper left side; the rising oil cylinder (25) is longitudinally bolted to the lower part of the press body (21). 4. The high-pressure gradient circulation drying system according to claim 2, characterized in that the upper motor (14) and upper filter cloth drum (15) and the lower motor (12) and lower filter cloth drum (13) It is arranged in two layers, upper and lower, to achieve multi-layer stacking of sludge between the double layers of filter cloth. 5. The high-pressure gradient circulation drying system according to claim 2, characterized in that a chain plate mechanism is provided inside the lower filter cloth drum (13). 6. The high-pressure gradient circulation drying system according to claim 2, characterized in that the sludge is spread on the lower filter cloth drum (13) of the distributor (7) through the distributor (7), and the lower filter cloth drum The filter cloth of (13) moves forward following the reciprocating motion of the chain plate mechanism driven by the lower motor (12), and the filter cloth of the upper filter cloth roller (15) synchronously follows the reversal of the combined pressure roller (14) driven by the upper motor (14). 16) Move forward and pass through the pre-adjusted gap between the upper and lower filter cloths of the lower filter cloth roller (13) and the upper filter cloth roller (15). 7. The high-pressure gradient circulation drying system according to claim 3, characterized in that the sludge is reciprocally stacked on the pressing frame through the left distributor system (1) and the right distributor system (3). (23), by pushing and pulling the oil cylinder (24) horizontally, move the press frame (23) to the filter press station. After the hydraulic station (22) is started, it drives the piston rod of the main oil cylinder (26) to move downward, thereby driving the press platform to The sludge in the pressing frame (23) is pressed and dehydrated. 8. The high-pressure gradient circulation drying system according to claim 3, characterized in that the hydraulic station (22) opens and drives the main oil cylinder (26) to lift upward to the initial working position; the horizontal push-pull oil cylinder (24) presses the The frame (23) moves to the transfer station, and the other press frame (23) also enters the filter press station to start pressing and dewatering; the sludge cake in the press frame (23) of the transfer station passes through the rising oil cylinder ( 25) Gradually push out the sludge cake during the reciprocating motion of the main body of the distributor (11). 9. The high-pressure gradient circulation drying system according to claim 1, characterized in that the pressing process of the left distributor system (1), the press system (2) and the right distributor system (3) No additives are needed, the pressing time is about 30 minutes, normal temperature is sufficient, and the working pressure is 6-8Mpa. 10. The high-pressure gradient circulation drying system and drying process according to claim 1, characterized in that the drying process of the high-pressure gradient circulation drying system mainly includes the following steps: Step 1: Humidification and discharging of sludge bin; Step 2: Stack the sludge between the double layers of filter cloth in multiple layers; Step 3: Stacking of reciprocating compressors of sludge; Step 4: Forming of deeply dehydrated dry mud cake; Step 5: The dry mud cake is completely peeled off.