Printing roller processing wastewater treatment system

Abstract

The utility model provides a printing roller processing wastewater treatment system which comprises a first heat exchanger, an evaporation tank and a steam compressor, a heater is arranged between a wastewater outlet of the first heat exchanger and a wastewater inlet of the evaporation tank, and a wastewater opening of the evaporation tank is connected to an inlet of a circulating pump. An outlet of the circulating pump is connected to a wastewater inlet of the first heat exchanger; a steam outlet of the evaporation tank is connected to a steam inlet of the steam compressor, a steam outlet of the steam compressor is connected to a steam inlet of the first heat exchanger, and a steam outlet of the first heat exchanger is condensed into water through a secondary cooling device. According to the utility model, the problem that a large amount of water resources are wasted if waste water generated after the plate roller is processed and treated is directly discharged is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage purification, in particular to a wastewater treatment system for plate roller processing. Background Art

[0002] In the production process of gravure printing plate rollers, nickel needs to be plated on the roller body to improve the bonding force between the roller and the copper layer, then copper is plated on the roller body and patterns are engraved on the surface of the roller body, and finally chromium is plated on the roller to improve the wear resistance of the plate roller. After nickel plating and chromium plating, the plate roller needs to be cleaned to remove the electroplating solution and other impurities adhering to the roller, so a large amount of sewage containing nickel and chromium ions will be generated, and chemical drugs such as acids and alkalis are needed to treat the sewage to meet the discharge standards. Since the treated wastewater mainly contains sodium sulfate and the amount of wastewater in the factory is very large, direct discharge will cause a large waste of water resources. At the same time, in order to respond to the national clean production and zero discharge policies, a wastewater treatment system for plate roller processing needs to be invented. Content of the Utility Model

[0003] The purpose of the utility model is to provide a wastewater treatment system for plate roller processing, which solves the problem that if the wastewater after plate roller processing is directly discharged, it will cause a large waste of water resources.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] A wastewater treatment system for plate roller processing includes a first heat exchanger, an evaporation tank, and a steam compressor. A heater is arranged between the wastewater outlet of the first heat exchanger and the wastewater inlet of the evaporation tank. The wastewater outlet of the evaporation tank is connected to the inlet of a circulation pump, and the outlet of the circulation pump is connected to the wastewater inlet of the first heat exchanger. The steam outlet of the evaporation tank is connected to the steam inlet of the steam compressor, the steam outlet of the steam compressor is connected to the steam inlet of the first heat exchanger, and the steam outlet of the first heat exchanger is condensed into water through a secondary cooling device.

[0006] Further, the secondary cooling device includes a second heat exchanger. The steam inlet of the second heat exchanger is connected to the steam outlet of the first heat exchanger, and the second heat exchanger is provided with a condensate outlet.

[0007] Further, the condensate outlet is connected to a condensate collection tank, and the condensate outlet of the condensate collection tank is connected to a condensate discharge pump.

[0008] Further, the inlet of the circulation pump is connected to the wastewater outlet of a feed water tank, and a feed pump, a feed angle valve, and a feed ball valve are sequentially connected between the wastewater outlet of the feed water tank and the inlet of the circulation pump.

[0009] Further, the inlet of the circulation pump is also connected to the outlet of the cleaning pump. Between the outlet of the cleaning pump and the inlet of the circulation pump, a first cleaning valve and a check valve are connected in sequence. The outlet of the check valve is connected to the pipeline between the feed angle valve and the feed ball valve. The inlet of the check valve is connected to the pipeline between the first cleaning valve and the second cleaning valve. The outlet of the second cleaning valve is connected to the low-level waste outlet at the bottom of the evaporation tank.

[0010] Further, the outlet of the circulation pump is connected to the inlet of the fourth discharge valve for the waste water inlet of the first heat exchanger. The outlet of the fourth discharge valve is connected to the inlet of the discharge pump and the outlet of the first discharge valve.

[0011] Further, the low-level waste outlet of the evaporation tank is connected to the inlet of the salt separation tank. A cooler is connected to the salt separation tank. The fresh brine outlet of the salt separation tank is connected to the fresh brine inlet of the feed water tank.

[0012] Further, between the low-level waste outlet of the evaporation tank and the salt separation tank, a first discharge valve, a discharge pump, a second discharge valve, a cooling and stirring tank, and a salt discharge pump are connected in sequence. The outlet of the salt discharge pump is connected to the inlet of the salt separation tank.

[0013] Further, a high-level waste outlet is provided at the lower part of the evaporation tank. The high-level waste outlet is connected to the inlet of the third discharge valve. The outlet of the third discharge valve is connected to the inlet of the second discharge valve.

[0014] Further, the drain outlet of the salt separation tank is connected to the inlet of the salt water pump. The outlet of the salt water pump is connected to the inlet of the feed water tank.

[0015] The beneficial effects of the present utility model: Through the system provided by the present utility model, the waste water treated by the system after pre-treatment of sewage can be circularly heated and evaporated. The purified water condensed can be stored and reused. The excess salts can also be crystallized and recovered through low-temperature precipitation, which well solves the problem that if the water used after the processing of the printing cylinder is directly discharged, a large amount of water resources will be wasted.

[0016] The following will combine the drawings and embodiments to make a relatively detailed description of the present utility model. Description of the Drawings

[0017] Figure 1 It is a system diagram of a printing cylinder processing waste water treatment system of the present utility model. Specific Embodiments

[0018] Such as Figure 1A plate roller processing wastewater treatment system is shown, which includes a first heat exchanger, an evaporation tank, and a steam compressor. A heater is arranged between the wastewater outlet of the first heat exchanger and the wastewater inlet of the evaporation tank. The wastewater outlet of the evaporation tank is connected to the inlet of a circulation pump 4, and the outlet of the circulation pump 4 is connected to the wastewater inlet of the first heat exchanger. The steam outlet of the evaporation tank is connected to the steam inlet of the steam compressor, and the steam outlet of the steam compressor is connected to the steam inlet of the first heat exchanger. The steam outlet of the first heat exchanger is condensed into water through a secondary cooling device. A cooling inlet and outlet are provided on the steam compressor, and the cooling inlet and outlet are connected to a steam compressor cooling pump 15 and a cooling water tank to perform water circulation cooling on the steam compressor. Pressure sensors and temperature sensors are provided on the steam inlet and steam outlet pipelines of the steam compressor.

[0019] Preferably, in combination with the above solution, in order to further cool the steam and achieve a better condensation effect, the secondary cooling device includes a second heat exchanger. The steam inlet of the second heat exchanger is connected to the steam outlet of the first heat exchanger, and the second heat exchanger is provided with a condensate outlet. The second heat exchanger is provided with a cooling inlet and a cooling outlet, and a cooling circulation pump 16 is arranged on the cooling pipeline.

[0020] Preferably, in combination with the above solution, in order to store and discharge and recycle the condensed purified water, the condensate outlet is connected to a condensate collection tank, and the condensate outlet of the condensate collection tank is connected to a condensate discharge pump 17.

[0021] Preferably, in combination with the above solution, in order to pump the stored wastewater into the treatment system, the inlet of the circulation pump 4 is connected to the wastewater outlet of a feed water tank. A feed pump 1, a feed angle valve 2, and a feed ball valve 3 are sequentially connected between the wastewater outlet of the feed water tank and the inlet of the circulation pump 4. A differential pressure level gauge is arranged in the evaporation tank for easy control. When the evaporation tank is at a low liquid level and needs to be replenished with water, the feed pump 1, the feed angle valve 2, and the feed ball valve 3 are opened to let water in. When the evaporation tank is at a high liquid level, the feed pump 1, the feed angle valve 2, and the feed ball valve 3 are closed.

[0022] Preferably, in combination with the above solution, in order to solve the problem of crystallization blockage, clean water is supplemented to the first heat exchanger and the evaporation tank for flushing. The inlet of the circulation pump 4 is also connected to the outlet of a cleaning pump 5. A first cleaning valve 6 and a check valve 15 are sequentially connected between the outlet of the cleaning pump 5 and the inlet of the circulation pump 4. The outlet of the check valve 15 is connected to the pipeline between the feed angle valve 2 and the feed ball valve 3. The inlet of the check valve 15 is connected to the pipeline between the first cleaning valve 6 and a second cleaning valve 7. The outlet of the second cleaning valve 7 is connected to the low-level waste outlet at the bottom of the evaporation tank.

[0023] Preferably, in combination with the above solution, in order to facilitate the discharge of wastewater from the circulation pump 4 and the first heat exchanger, the outlet of the circulation pump 4 is connected to the inlet of the fourth discharge valve 14 at the wastewater inlet of the first heat exchanger, and the outlet of the fourth discharge valve 14 is connected to the inlet of the discharge pump 9 and the outlet of the first discharge valve 8.

[0024] Preferably, in combination with the above solution, in order to recover the crystallized precipitate of sodium sulfate in the wastewater and recycle the fresh brine, the low-level waste outlet of the evaporation tank is connected to the inlet of the salt separation tank, a cooler is connected to the salt separation tank, and the fresh brine outlet of the salt separation tank is connected to the fresh brine inlet of the feed water tank.

[0025] Preferably, in combination with the above solution, in order to discharge the low-level concentrated brine crystal material at the lower part of the evaporation tank, a first discharge valve 8, a discharge pump 9, a second discharge valve 10, a cooling and stirring tank, and a salt discharge pump 11 are sequentially connected between the low-level waste outlet of the evaporation tank and the salt separation tank, and the outlet of the salt discharge pump 11 is connected to the inlet of the salt separation tank.

[0026] Preferably, in combination with the above solution, in order to discharge a part of the high-level concentrated brine crystal material when the low-level waste outlet of the evaporation tank is blocked, a high-level waste outlet is provided at the lower part of the evaporation tank, the high-level waste outlet is connected to the inlet of the third discharge valve 13, and the outlet of the third discharge valve 13 is connected to the inlet of the second discharge valve 10.

[0027] Preferably, in combination with the above solution, in order to better extract the fresh brine in the salt separation tank, the drain outlet of the salt separation tank is connected to the inlet of the salt water pump 12, and the outlet of the salt water pump 12 is connected to the inlet of the feed water tank.

[0028] The working principle of the system of the present utility model:

[0029] The steam compressor extracts the low-temperature steam inside the evaporation tank, does work on the low-temperature steam to increase the steam temperature, and reaches the required set temperature set by the heat exchange system. The secondary steam is recycled by using the steam compressor.

[0030] The heat exchanger exchanges heat between the high-temperature steam generated by the work of the steam compressor and the wastewater, and cooperates with the electromagnetic heater to heat the wastewater to reach the evaporation temperature required for the liquid in the evaporation tank.

[0031] The wastewater in the evaporation tank exchanges heat through the heat exchanger and at the same time cooperates with the steam compressor to draw a negative pressure to reach the evaporation temperature of the liquid in the evaporation tank, and evaporation is achieved in the evaporation tank. As the wastewater evaporates and concentrates, the salt content in the wastewater gradually increases to reach the saturated and critical saturated state, and part of the crystals will precipitate from the wastewater in the evaporation tank and then be processed subsequently.

[0032] The main wastewater treatment process is as follows: After the plate roller processing wastewater treated in the previous process is collected in the feed water tank, the wastewater passes through the feed pump 1, feed angle valve 2, and feed ball valve 3 and reaches the treatment system. The wastewater is circulated and heated in turn through the first heat exchanger, the electromagnetic heater on the pipeline, the evaporation tank, and the circulation pump. The steam compressor can draw negative pressure in the evaporation tank and heat the circulating water temperature in the treatment system to about 90°C for evaporation. The high-temperature steam in the evaporation tank can reach about 110°C after entering the steam compressor. The high-temperature steam then enters the first heat exchanger to continue heating the wastewater in the first heat exchanger. The steam with cooled temperature enters the second heat exchanger from the first heat exchanger for secondary cooling, forming clean condensed water and entering the cooling water collection tank for reuse.

[0033] As the concentration of the wastewater evaporation increases, the salt content in the wastewater gradually rises, reaching the saturated and critical saturated states. Part of the crystallization will precipitate from the wastewater in the evaporation tank. The concentrated brine and crystallization in the evaporation tank can be discharged through the low-level waste outlet at the bottom of the evaporation tank, passing through the first discharge valve 8, discharge pump 9, and second discharge valve 10 and reaching the cooling and stirring tank for stirring and cooling. After the temperature drops, it is discharged into the salt precipitation tank through the salt discharge pump 11 for low-temperature salt precipitation. The outer wall of the salt precipitation tank is wound with a cooling pipe with coolant, or there is a sandwich in the salt precipitation tank, and the coolant is arranged in the sandwich; both ends of the cooling pipe are connected to the cooler to cool the concentrated brine to about 6°C. At this time, sodium sulfate in the concentrated brine will crystallize and precipitate, and finally, the crystallization is shoveled out manually for recovery. The fresh brine in the salt precipitation tank is then pumped into the feed water tank through the salt water pump for recycling.

[0034] After the system operates for a period of time, salts or viscous substances will adhere to the inner wall of the heat exchanger and in the evaporation tank, resulting in a decrease in the heat exchange efficiency of the system, thus affecting the evaporation volume and even causing crystallization blockage. Therefore, the system needs to be cleaned. Cleaning can be done with clean water flushing. To make the cleaning effect better, it can be first cleaned with acid and alkali solutions and then with clean water. The acid cleaning solution can use a dilute sulfuric acid solution with a pH value between 5 and 6; the alkali cleaning solution can use a sodium carbonate cleaning solution with a pH value of about 8 to 9; and it is necessary to clean with acid first, then with alkali, and then with clean water.

[0035] When the evaporation tank is blocked by crystallization, the cleaning pump 5 can be opened, and the cleaning water passes through the cleaning valve 6, check valve 15, and feed ball valve 3 in turn and enters the treatment system to dilute the concentrated brine, and the heated wastewater can also assist in dissolving the crystallization.

[0036] When the evaporation tank is severely blocked by crystallization, at this time, the first discharge valve 8 cannot discharge the low-level crystallization. The third discharge valve 13 can be opened first, and part of the high-level crystallization can be discharged into the cooling and stirring tank. The cleaning pump 5 can be started, and the cleaning water can be flushed into the low-level waste outlet at the bottom of the evaporation tank through the first cleaning valve 6, the second cleaning valve 7, and the first discharge valve 8 in sequence to try to flush open the crystallization. At the same time, the cleaning water can also be discharged into the treatment system through the feed ball valve 3 to dilute the concentrated brine and dissolve the crystallization.

[0037] In addition, in this embodiment, the first heat exchanger and the second heat exchanger can respectively adopt the HR-MJ-90 and HR-6 models provided by Qingdao Hongju Environmental Protection Engineering Co., Ltd. The steam compressor can adopt the SR-200 model provided by Xi'an Shaanxi Drum Power Co., Ltd., and the cooler can adopt the TZA-3AC air-cooled chiller provided by Suzhou Tianzhiao Technology Co., Ltd.

[0038] The above has made an exemplary description of a plate roller processing wastewater treatment system of the present invention in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as various improvements are made by adopting the method concept and technical solution of the present invention, or directly applied to other occasions without improvement, they all fall within the protection scope of the present invention.

Claims

1. A plate roller processing wastewater treatment system, characterized in that: The invention comprises a first heat exchanger, an evaporator, and a steam compressor. A heater is arranged between the wastewater outlet of the first heat exchanger and the wastewater inlet of the evaporator. The wastewater outlet of the evaporator is connected to the inlet of a circulation pump (4), and the outlet of the circulation pump (4) is connected to the wastewater inlet of the first heat exchanger. The steam outlet of the evaporator is connected to the steam inlet of the steam compressor, and the steam outlet of the steam compressor is connected to the steam inlet of the first heat exchanger. The steam outlet of the first heat exchanger is condensed into water through a secondary cooling device.

2. The plate roller processing wastewater treatment system according to claim 1 is characterized in that: The secondary cooling device comprises a second heat exchanger, a steam inlet of the second heat exchanger is connected to a steam outlet of the first heat exchanger, and the second heat exchanger is provided with a condensed water outlet.

3. The roller processing wastewater treatment system according to claim 2 is characterized in that: The condensed water outlet is connected to a condensed water collection tank, and the condensed water outlet of the condensed water collection tank is connected to a condensed water discharge pump (17).

4. The plate roller processing wastewater treatment system according to claim 1 is characterized in that: The inlet of the circulation pump (4) is connected to the wastewater outlet of the feed water tank, and the feed pump (1), the feed angle valve (2), and the feed ball valve (3) are connected in sequence between the wastewater outlet of the feed water tank and the inlet of the circulation pump (4).

5. The plate roller processing wastewater treatment system according to claim 4 is characterized in that: The inlet of the circulation pump (4) is also connected to the outlet of the cleaning pump (5); the outlet of the cleaning pump (5) and the inlet of the circulation pump (4) are connected to the first cleaning valve (6) and the one-way valve (15) in sequence; the outlet of the one-way valve (15) is connected to the pipeline between the feed angle valve (2) and the feed ball valve (3); the inlet of the one-way valve (15) is connected to the pipeline between the first cleaning valve (6) and the second cleaning valve (7); the outlet of the second cleaning valve (7) is connected to the low-level waste port at the bottom of the evaporation tank.

6. The plate roller processing wastewater treatment system according to claim 5 is characterized in that: The outlet of the circulation pump (4) and the wastewater inlet of the first heat exchanger are connected to the inlet of the fourth discharge valve (14), and the outlet of the fourth discharge valve (14) is connected to the inlet of the discharge pump (9) and the outlet of the first discharge valve (8).

7. The plate roller processing wastewater treatment system according to claim 5 is characterized in that: The low-level waste port of the evaporation tank is connected to the inlet of the salt precipitation box, the salt precipitation box is connected to a cooler, and the brine outlet of the salt precipitation box is connected to the brine inlet of the feed water tank.

8. The plate roller processing wastewater treatment system according to claim 7 is characterized in that: A first discharge valve (8), a discharge pump (9), a second discharge valve (10), a cooling and stirring box, and a salt discharge pump (11) are sequentially connected between the low-level waste outlet of the evaporation tank and the salt precipitation box, and the outlet of the salt discharge pump (11) is connected to the inlet of the salt precipitation box.

9. The plate roller processing wastewater treatment system according to claim 8 is characterized in that: A high-position waste port is provided at the lower part of the evaporation tank, and the high-position waste port is connected to the inlet of the third discharge valve (13), and the outlet of the third discharge valve (13) is connected to the inlet of the second discharge valve (10).

10. The plate roller processing wastewater treatment system according to claim 8, characterized in that: The drain outlet of the salt precipitation box is connected to the inlet of the brine pump (12), and the outlet of the brine pump (12) is connected to the inlet of the feed water tank.

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