Aerating fan combined filter press sludge drying system

Abstract

This invention discloses a sludge drying system combining an aeration blower and a filter press. The aerobic tank of a wastewater treatment plant requires aeration blowers for aeration. Due to the high pressure, the blowers output high-temperature, low-humidity dry air. Sludge is inevitably generated during wastewater treatment. Existing solutions initially use mechanical filter press drying, followed by off-site disposal or further drying, both of which increase costs and energy consumption. This invention combines an aeration blower and a sludge filter press for sludge drying. The sludge is first pumped to the filter press via a diaphragm pump, and then the flow path of the aeration blower is switched and introduced into the filter press. The aeration blower generates high-temperature air to heat the sludge cake and remove moisture. The gas and filtrate are then sent together to a gas-liquid separator. The filtrate is discharged in batches according to the liquid level, and the gas is introduced into the aeration tank for aeration.

Description

Technical Field

[0001] This invention relates to the field of sludge drying technology, and in particular to a sludge drying system combining an aeration blower and a filter press. Background Technology

[0002] Wastewater treatment plants are equipped with aerobic tanks. Aeration blowers aerate and oxygenate these tanks. For every meter the water depth increases in the aerobic tank, the exhaust temperature of the blowers rises by approximately 12°C from room temperature. Since aerobic tanks are typically 4-6 meters deep, the exhaust temperature rises by 48-72°C. Directly supplying this heat to the aerobic tank results in wasted energy. Furthermore, wastewater treatment inevitably produces large amounts of wet sludge. Currently, this is typically handled through mechanical filtration followed by off-site disposal or deep drying using drying equipment. Both methods increase energy consumption and costs, failing to fully utilize the waste heat from the wastewater treatment system and thus hindering energy conservation and environmental protection. Summary of the Invention

[0003] To fully utilize the waste heat from wastewater treatment plants for deep drying of sludge, thereby saving energy and costs, this invention provides a sludge drying system combining an aeration blower and a filter press for deep drying of sludge. To achieve the above objectives, this invention adopts the following technical solution: The sludge drying system combining an aeration blower and a filter press provided by this invention includes a sludge filter pressing unit and an aerobic tank aeration unit. The sludge filter pressing unit includes a sludge tank, a diaphragm pump, a filter press, a gas-liquid separator, and a drain valve. The diaphragm pump pumps the prepared sludge from the sludge tank to the filter press. The filtrate produced during the filter pressing process is transported through pipelines to the gas-liquid separator tank. The filtrate is then discharged into the wastewater tank through the drain valve according to the liquid level inside the gas-liquid separator tank. The aerobic tank aeration unit includes an aeration blower, an inlet valve, an outlet valve, a bypass valve, and an aerobic tank. The aeration blower draws in air and discharges high-pressure, high-temperature, low-humidity air. This gas is guided to the filter press through the opening of the inlet valve and outlet valve and the closing of the bypass valve to heat and dehumidify the sludge cake. The sludge cake and the gas are in direct contact with each other through the filter cloth, and the two can exchange energy and matter. Then, the cooled and humidified air and filtrate are transported to the gas-liquid separator tank through pipelines. The air after gas-liquid separation is sent to the aerobic tank for aeration through pipelines.

[0004] Furthermore, the filter press may be a plate and frame filter press, a chamber filter press, or a high-pressure box filter press.

[0005] Furthermore, the diaphragm pump used in this invention to transport sludge from the sludge tank to the filter press can be replaced with other pumps, such as screw pumps, depending on different requirements.

[0006] The filter plates in the filter press of the sludge filter press unit mentioned above need to have openings at the top and bottom to facilitate the entry of high-temperature, low-humidity air from the aeration blower and the discharge of air and filtrate to the gas-liquid separator.

[0007] The high-temperature, low-humidity air generated by the aeration blower in the aerobic tank aeration unit is used to dry and dehumidify the sludge while ensuring aeration of the aerobic tank through the opening and closing of the inlet valve, outlet valve, and bypass valve.

[0008] The gas-liquid separator in the sludge depressurization unit can control the opening and closing of the drain valve according to the liquid level to drain the liquid and ensure the stable aeration pressure of the aerobic tank.

[0009] The filter press in the sludge filter press unit has a connector and a flexible conduit installed above the filter plate to connect to the air inlet manifold on the top of the filter press, and a connector and a flexible conduit installed below the filter plate to connect to the exhaust manifold below the filter press.

[0010] A gas-liquid separator is provided between the filter press and the aerobic tank.

[0011] The embodiments of the present invention have at least the following beneficial effects: utilizing the waste heat of the high-temperature, low-humidity gas generated by the aeration blower enhances the sludge drying effect and saves on sludge drying costs; the cooled gas continues to flow into the aerobic tank for aeration without affecting the aeration effect of the original aeration system. The present invention can be widely used in the field of sludge drying in wastewater treatment plants. Attached Figure Description

[0012] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Figure 1 This is a schematic diagram of the sludge drying system of an aeration blower combined with a filter press according to the present invention.

[0014] Explanation of reference numerals in the attached figures: 1. Aeration blower; 2. Filter press; 3. Gas-liquid separator; 4. Aerobic tank; 5. Sludge tank; 6. Diaphragm pump; 7. Inlet valve; 8. Outlet valve; 9. Bypass valve; 10. Drain valve; Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0016] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0017] Example 1 Reference Figure 1 This is the first embodiment of the present invention, which provides an aeration blower combined with a filter press sludge drying system, comprising a sludge filter press unit and an aerobic tank aeration unit. Specifically, in the aerobic tank aeration unit, the inlet valve (7) and outlet valve (8) are closed, the bypass valve (9) is opened, and the aeration blower (1) is started to aerate the aerobic tank (4).

[0018] Then the hydraulic system in the filter press (2) of the sludge filter press unit is started to lock the pressure. The diaphragm pump (6) is started to pump the sludge prepared in the sludge tank (5) to the filter press (2) for filtration. The solid matter in the sludge is intercepted by the filter plate. The filtrate passes through the filter plate and is collected in the exhaust manifold below the filter press through the drain hole of the filter plate. It is then transported to the gas-liquid separator (3) through the pipeline. When the liquid level in the gas-liquid separator (3) rises to the high point, the drain valve (10) is opened to discharge the filtrate to the sewage tank. When the liquid level drops to the low point, the drain valve (10) is closed.

[0019] After the sludge filter press (2) has been running for a period of time, open the air inlet valve (7) and the air outlet valve (8), and then close the bypass valve (9) to guide the high temperature and low humidity air generated by the aeration blower (1) into the filter press (2). The high temperature and low humidity air enters each filter plate through the air inlet manifold and deeply dries the sludge cake through the filter plate, which can reduce the moisture content of the sludge cake to below 30%. After the set drying time is reached, open the bypass valve (9), close the air inlet valve (7) and the air outlet valve (8), close the diaphragm pump (6), and the filter press (2) will depressurize and discharge the sludge. The sludge cake will fall into the hopper below the filter press (2).

[0020] Example 2 Reference Figure 1This is the first embodiment of the present invention, which provides an aeration blower combined with a filter press sludge drying system, comprising a sludge filter press unit and an aerobic tank aeration unit. Specifically, in the aerobic tank aeration unit, the inlet valve (7) and outlet valve (8) are closed, the bypass valve (9) is opened, and the aeration blower (1) is started to aerate the aerobic tank (4).

[0021] Then, the hydraulic system in the filter press (2) of the sludge dewatering unit is activated to lock the pressure. The diaphragm pump (6) is activated to pump the prepared sludge from the sludge tank (5) to the filter press (2) for dewatering. The solid matter in the sludge is intercepted by the filter plate, and the filtrate passes through the filter plate and is collected in the exhaust manifold below the filter press through the drain hole of the filter plate. It is then transported to the gas-liquid separator (3) through the pipeline. When the liquid level in the gas-liquid separator (3) rises to the high point, the drain valve (10) is opened to discharge the filtrate to the sewage tank. When the liquid level drops to the low point, the drain valve (10) is closed. The filter press is then purged with compressed air or high-pressure liquid to perform secondary dewatering of the sludge cake.

[0022] After the sludge filter press (2) has been running for a period of time, the pressure of the secondary filter press is released. The air inlet valve (7) and the air outlet valve (8) are opened, and the bypass valve (9) is closed to guide the high temperature and low humidity air generated by the aeration blower (1) into the filter press (2). The high temperature and low humidity air enters each filter plate through the air inlet manifold and the sludge cake is deeply dried through the filter plate, which can reduce the moisture content of the sludge cake to below 30%. After the set drying time is reached, open the bypass valve (9), close the air inlet valve (7) and the air outlet valve (8), close the diaphragm pump (6), and the filter press (2) will depressurize and discharge the sludge. The sludge cake will fall into the hopper below the filter press (2).

[0023] As shown, The above descriptions are merely some embodiments of the present invention.

Claims

1. A sludge drying system combining an aeration blower and a filter press, characterized in that: include The sludge dewatering unit includes a sludge tank (5), a diaphragm pump (6), a filter press (2), a gas-liquid separator (3), and a drain valve (10). The diaphragm pump (6) pumps the sludge prepared in the sludge tank (5) into the filter press (2). The filtrate generated during the dewatering process is transported to the gas-liquid separator tank (3) through a pipeline. The filtrate is then discharged into the wastewater tank through the drain valve (10) according to the liquid level.

2. Aerobic tank aeration unit, the aerobic tank aeration unit includes an aeration blower (1), an inlet valve (7), an outlet valve (8), a bypass valve (9), and an aerobic tank (4). The high-pressure, high-temperature, low-humidity air generated by the aeration blower (1) is guided to the filter press (2) through the opening of the inlet valve (7) and the outlet valve (8) and the closing of the bypass valve (9) to heat and dehumidify the sludge cake. The sludge cake and the high-temperature, low-humidity gas are in direct contact with the filter cloth, and the two can exchange energy and matter. Then, the cooled and humidified air and filtrate are transported to the gas-liquid separator tank (3) through the pipeline. The air after gas-liquid separation is sent to the aerobic tank (4) through the pipeline for aeration.

3. The sludge drying system combining aeration blower and filter press according to claim 1, characterized in that, The filter press (2) in the sludge filter press unit mentioned above, and the filter plate in the filter press, need to have holes in the upper and lower parts to facilitate the entry of high temperature and low humidity air from the aeration blower (1) and the discharge of air and filtrate to the gas-liquid separator (3).

4. The sludge drying system combining aeration blower and filter press according to claim 1, characterized in that, The high-temperature, low-humidity air generated by the aeration blower (1) in the aerobic tank aeration unit is used to dry and dehumidify the sludge while ensuring aeration of the aerobic tank (4) through the opening and closing of the inlet valve (7), outlet valve (8), and bypass valve (9).

5. The sludge drying system combining aeration blower and filter press according to claim 1, characterized in that, The gas-liquid separator (3) in the sludge filter press unit can control the opening and closing of the drain valve (10) according to the liquid level to drain the liquid and ensure the stable aeration pressure of the aerobic tank.

6. The sludge drying system combining aeration blower and filter press according to claim 2, characterized in that, The filter press (2) in the sludge filter press unit has a connector and a flexible conduit installed above the filter plate to connect to the air inlet manifold above the filter press (2), and a connector and a flexible conduit installed below the filter plate to connect to the exhaust manifold below the filter press (2).

7. The sludge drying system combining aeration blower and filter press according to claims 3 to 4, characterized in that, A gas-liquid separator (3) is provided between the filter press (2) and the aerobic tank (4).

Images