A system and method for recycling and utilizing wastewater from fiber cement boards.

Abstract

A system and method for recycling and utilizing wastewater from fiber cement board production includes a blanket with an absorbent hood underneath. The absorbent hood is connected to a pumping tank via a pipe, and the pumping tank is connected to a vacuum pump. The system also includes a drainage ditch located beneath the blanket, one end of which connects to a pit containing a stirrer. The bottom of the pit is connected to a sedimentation tank inlet via a submersible pump, and the sedimentation tank outlet is connected to a circulating water tank via a pipe. The bottom of the sedimentation tank is connected to a mixing section via a mud pump. The bottom of the circulating water tank is connected to a flushing pipe equipped with a circulating water pump, a diversion pipe, and multiple nozzles. One end of the diversion pipe is located within the drainage ditch, and the nozzles are used to flush the blanket. A first solenoid valve is installed on the diversion pipe. The pit is connected to a feeding tank via a feeding pipe. This invention addresses the problems of easily clogging pipes and pits in fiber cement board production, affecting production capacity and resulting in high solid waste disposal costs.

Description

Technical Field

[0001] This invention relates to a system and method for recycling and utilizing wastewater from fiber cement boards. Background Technology

[0002] The production process of fiber cement board involves preparing various raw materials into a slurry of a certain concentration, spreading it evenly on a permeable blanket, and then vacuum dewatering it to form a semi-dry wet blank, which is then pressed into shape. During the vacuum dewatering process, fine aggregates are lost and return to the system's circulating water. These aggregates, mainly composed of cement and mortar, are prone to sedimentation and hardening, clogging pipes and pits, thus hindering normal fiber cement board production and necessitating frequent cleaning of pits and pipes, impacting production capacity. Furthermore, the waste generated cannot be recycled, resulting in high monthly solid waste disposal costs. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a system and method for recycling and reusing wastewater from fiber cement board production, which solves the problems of easy blockage of pipes and pits by water used in fiber cement board production, affecting production capacity and high cost of cleaning up solid waste.

[0004] To solve the above problems, the technical solution of the present invention is as follows:

[0005] A wastewater recycling system for fiber cement boards includes a blanket with an absorbent hood underneath. The absorbent hood is connected to a pumping tank via a pipe, and the pumping tank is connected to a vacuum pump. The system also includes a drainage ditch located beneath the blanket, one end of which connects to a pit containing a stirrer. The bottom of the pit is connected to a sedimentation tank inlet via a submersible pump, and the sedimentation tank outlet is connected to a circulating water tank via a pipe. The bottom of the sedimentation tank is connected to a mixing section via a mud pump. The bottom of the circulating water tank is connected to a flushing pipe equipped with a circulating water pump, a diversion pipe, and multiple nozzles. One end of the diversion pipe is located within the drainage ditch, and the nozzles are used to flush the blanket. A first solenoid valve is installed on the diversion pipe, and the pit is connected to... The system includes a feed tank connected via a feed pipe, a metering pump installed on the feed pipe, a water supply pipe connected to the circulating water tank, a second solenoid valve installed on the water supply pipe, a drainage ditch connected to the pumping tank via a drain pipe, a third solenoid valve installed on the drain pipe, a first liquid level sensor installed on the pit, a second liquid level sensor installed on the circulating water tank, a vent pipe connected to the pumping tank, a fourth solenoid valve installed on the vent pipe, and a controller. The first and second liquid level sensors are connected to the controller input, and the first, second, third, and fourth solenoid valves, the metering pump, the submersible pump, the agitator, and the circulating water pump are connected to the controller output.

[0006] The beneficial effects of this invention are as follows: after adding flocculant to the water filtered by the blanket, it is pumped to the sedimentation tank for sedimentation. The precipitated clear water can be reused, and the precipitated sludge is sent to the mixing section to be mixed with fiber cement board raw materials and reused. No wastewater is generated in the entire wastewater recycling process. At the same time, the wastewater is used to intermittently flush the ditches to ensure that there are no hardened sediments in the ditches and pits. Attached Figure Description

[0007] The invention will be further described below with reference to the accompanying drawings:

[0008] Figure 1 This is a schematic diagram of the structure of the present invention.

[0009] Figure 2 This is a schematic diagram of the enlarged structure of the present invention.

[0010] Figure 3 This is a schematic diagram showing the connection relationship between the various electrical components of the present invention.

[0011] In the diagram: 1. Air pump; 2. Water tank; 3. Blanket; 4. Nozzle; 5. Water suction cover; 6. Drainage ditch; 7. Pit; 8. Sedimentation tank; 9. Circulating water tank; 21. Fourth solenoid valve; 22. Third liquid level sensor; 23. Fifth solenoid valve; 24. Water distribution pipe; 25. First solenoid valve; 26. Third solenoid valve; 71. First liquid level sensor; 72. Submersible pump; 73. Agitator; 74. Metering pump; 81. Slurry pump; 82. Mixing section; 91. Second solenoid valve; 92. Overflow valve; 93. Circulating water pump; 94. Second liquid level sensor. Detailed Implementation

[0012] like Figures 1 to 3As shown, a wastewater recycling system for fiber cement boards includes a blanket 3, with an absorbent hood 5 located below the blanket 3. The absorbent hood 5 is connected to a pumping tank 2 via a pipe. The pumping tank 2 is connected to a vacuum pump 1. The system also includes a drainage ditch 6 located below the blanket 3. One end of the drainage ditch 6 is connected to a pit 7. A stirrer 73 is installed in the pit 7. The bottom of the pit 7 is connected to the inlet of a sedimentation tank 8 via a submersible pump 72. The outlet of the sedimentation tank 8 is connected to a circulating water tank 9 via a pipe. The bottom of the sedimentation tank 8 is connected to a mixing section 82 via a mud pump 81. The bottom of the circulating water tank 9 is connected to a flushing pipe. A circulating water pump 93, a diversion pipe, and multiple nozzles 4 are installed on the flushing pipe. One end of the diversion pipe is located inside the drainage ditch 6. The nozzles 4 are used to flush the blanket 3 or the mesh cage. A first solenoid valve 25 is installed on the diversion pipe. The pit 7 is connected to a feeding pipe. The system includes a material tank with a metering pump 74 installed on the feeding pipe, a circulating water tank 9 connected to tap water via a water supply pipe with a second solenoid valve 91 installed on the water supply pipe, a pumping tank 2 connected to a drainage ditch 6 via a drain pipe with a third solenoid valve 26 installed on the drain pipe, a first liquid level sensor 71 installed on the pit 7, a second liquid level sensor 94 installed on the circulating water tank 9, a venting pipe connected to the pumping tank 2 with a fourth solenoid valve 21 installed on the venting pipe, and a controller. The first liquid level sensor 71 and the second liquid level sensor 94 are connected to the controller input, and the vacuum pump 1, the first solenoid valve 25, the second solenoid valve 91, the third solenoid valve 26, the fourth solenoid valve 21, the metering pump 74, the submersible pump 72, the agitator 73, and the circulating water pump 93 are connected to the controller output. The controller is a PLC controller. The feeding tank, not shown in the diagram, contains a polyacrylamide solution.

[0013] A third liquid level sensor 22 is installed on the water tank 2. The flushing pipe is connected to the water distribution pipe 24 located inside the water tank 2 via the flushing pipe. The water distribution pipe 24 and the drain pipe are respectively located on both sides of the water tank 2. A fifth solenoid valve 23 is installed on the flushing pipe. The third liquid level sensor 22 is connected to the controller input terminal, and the fifth solenoid valve 23 is connected to the controller output terminal. To prevent sediment from accumulating in the water tank 2, the controller controls the fifth solenoid valve 23 to open intermittently, sending clean water intermittently into the clean water tank. The clean water evenly flushes the bottom of the water tank 2, preventing sediment from accumulating at the bottom of the water tank 2.

[0014] A check valve is installed on the pipe connecting the air pump 1 to the water tank 2 to prevent air from flowing back into the water tank 2.

[0015] The flushing pipe is connected to the circulating water tank 9 via an overflow pipe, and an overflow valve 92 is installed on the overflow pipe. The overflow valve 92 protects the circulating water pump 93 and the flushing pipe from excessive pressure and pipe bursting.

[0016] A method for recycling and utilizing wastewater from fiber cement board systems includes the following steps:

[0017] S1: The vacuum pump 1 starts, drawing water from the sizing material on the blanket 3 into the water tank 2. Simultaneously, the third liquid level sensor 22 monitors the water level in the water tank 2 in real time. When the water level reaches the high level, the controller controls the third solenoid valve 26 and the fourth solenoid valve 21 to open, and the vacuum pump 1 to stop. The water in the water tank 2 flows into the drainage ditch 6 through the drain pipe. When the third liquid level sensor 22 detects that the liquid level has reached the low level, the controller controls the fifth solenoid valve 23 to open for 10 seconds, allowing clean water to rinse the bottom of the water tank 2. After rinsing, the controller controls the third solenoid valve 26, the fourth solenoid valve 21, and the fifth solenoid valve 23 to close, and simultaneously starts the vacuum pump 1 to extract water from the sizing material on the blanket 3 again. This cycle is repeated.

[0018] S2: Water in drainage ditch 6 flows into pit 7. At the same time, the first liquid level sensor 71 detects the liquid level of water in pit 7 in real time. When the liquid level reaches the high level, metering pump 74 quantitatively extracts flocculant from feeding tank into pit 7. At the same time, stirrer 73 is started to mix flocculant with water in pit 7.

[0019] S3: Submersible pump 72 pumps water from pit 7 to sedimentation tank 8 for sedimentation. When the water level in pit 7 reaches a low level, submersible pump 72 stops. The clean water entering sedimentation tank 8 flows into circulating water tank 9. The sludge settled in sedimentation tank 8 is then sent by mud pump 81 to mixing section 82 to mix with fiber cement board raw materials, allowing the sludge to be reused.

[0020] S4: The water entering the circulating water tank 9 is pumped by the circulating water pump 93 to the nozzle 4 to rinse the blanket 3. At the same time, the first solenoid valve 25 is intermittently activated to intermittently rinse the drainage ditch 6 with the water in the circulating water tank 9 to prevent the sediment from hardening in the drainage ditch 6.

[0021] In addition, a second liquid level sensor 94 detects the liquid level in the circulating water tank 9 in real time. If the liquid level is low, the controller controls the second solenoid valve 91 to open and replenish the circulating water tank 9 with tap water.

Claims

1. A fiber cement board wastewater recycling system, comprising a blanket (3), a water absorption shell (5) is arranged below the blanket (3), the water absorption shell (5) is connected with a water suction box (2) through a pipeline, and the water suction box (2) is connected with a suction pump (1), characterized in that: Further comprising a drain ditch (6) arranged below the blanket (3), one end of the drain ditch (6) is communicated with a pit (7), the pit (7) is provided with a stirrer (73), the bottom of the pit (7) is communicated with a water inlet of a sedimentation tank (8) through a submerged pump (72), the water outlet of the sedimentation tank (8) is communicated with a circulating water tank (9) through a pipeline, the bottom of the sedimentation tank (8) is communicated with a mixing part (82) through a slurry pump (81), the bottom of the circulating water tank (9) is communicated with a flushing pipe, the flushing pipe is provided with a circulating water pump (93), a shunt pipe and a plurality of nozzles (4), one end of the shunt pipe is arranged in the drain ditch (6), the nozzles (4) are used for flushing the blanket (3), a first electromagnetic valve (25) is arranged on the shunt pipe, the pit (7) is communicated with a feeding tank through a feeding pipe, a metering pump (74) is arranged on the feeding pipe, the circulating water tank (9) is communicated with tap water through a water supplementing pipe, a second electromagnetic valve (91) is arranged on the water supplementing pipe, the water pumping tank (2) is communicated with the drain ditch (6) through a water discharging pipe, a third electromagnetic valve (26) is arranged on the water discharging pipe, a first liquid level sensor (71) is arranged on the pit (7), a second liquid level sensor (94) is arranged on the circulating water tank (9), a vent pipe is arranged on the water pumping tank (2) and communicated with the water pumping tank (2), a fourth electromagnetic valve (21) is arranged on the vent pipe, further comprising a controller, the first liquid level sensor (71) and the second liquid level sensor (94) are connected with an input end of the controller, the air pumping pump (1), the first electromagnetic valve (25), the second electromagnetic valve (91), the third electromagnetic valve (26), the fourth electromagnetic valve (21), the metering pump (74), the submerged pump (72), the stirrer (73) and the circulating water pump (93) are connected with an output end of the controller; a third liquid level sensor (22) is arranged on the water pumping tank (2), the flushing pipe is communicated with a water distribution pipe (24) arranged in the water pumping tank (2) through a flushing pipe, the water distribution pipe (24) and the water discharging pipe are arranged on two sides of the water pumping tank (2) respectively, a fifth electromagnetic valve (23) is arranged on the flushing pipe, and the fifth electromagnetic valve (23) is connected with the output end of the controller.

2. The fiber cement board wastewater recycling system according to claim 1, characterized in that: A one-way valve is arranged on the pipeline through which the air pumping pump (1) is communicated with the water pumping tank (2).

3. The fiber cement board wastewater recycling system of claim 1, wherein: The flushing pipe is communicated with the circulating water tank (9) through an overflow pipe, and an overflow valve (92) is arranged on the overflow pipe.

4. A method of using the wastewater recycling system for fiber cement board according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: S1: the air pumping pump (1) is started, and the water in the sizing material on the blanket (3) is pumped into the water pumping tank (2) by the air pumping pump (1), and the water in the water pumping tank (2) flows into the drain ditch (6) and enters the pit (7) with the intermittent starting of the third electromagnetic valve (26); S2: the water entering the pit (7) is detected by the first liquid level sensor (71), when the liquid level reaches a high liquid level, the metering pump (74) quantitatively extracts the flocculating agent in the feeding tank into the pit (7), at the same time, the stirrer (73) is started, and the flocculating agent is mixed with the water in the pit (7); S3: The submersible pump (72) pumps the water in the pit (7) to the sedimentation tank (8) for sedimentation. When the water level in the pit (7) is low, the submersible pump (72) stops, and the clean water in the sedimentation tank (8) flows into the circulating water tank (9), and the sludge deposited in the sedimentation tank (8) is pumped into the mixing part (82) by the sludge pump; S4: The water in the circulating water tank (9) is pumped to the nozzle (4) by the circulating water pump (93) to wash the blanket (3), and the first electromagnetic valve (25) is intermittently started to intermittently wash the water in the circulating water tank (9) to the drain (6).

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