Rust removal method for plate heat exchanger

Abstract

The invention provides a plate heat exchanger derusting method which comprises the following steps: circulating water flows out of a secondary side outlet of a plate heat exchanger, and the circulating water flows into a cooling water tower after passing through a negative electron generator; circulating water flows into the water storage tank after being cooled by the cooling water tower and flows into the bag type filter; the bag filter is used for filtering particle impurities in the circulating water; the circulating water flows through the negative electron generators, the circulating water flows back to the plate heat exchanger, and rust removal is conducted on the plate heat exchanger. Through cooperation of the 2-3 negative electron generators, the lifting water pump and the bag type filter, the circulating water circularly flows in the whole pipeline, rust in the pipeline and the plate heat exchanger is removed; according to the plate heat exchanger, rust deposition on the plate of the plate heat exchanger is avoided, the plate of the plate heat exchanger does not need to be disassembled or cleaned during equipment maintenance, the workload of equipment maintenance is greatly reduced, no chemical agent is used in the scheme, the plate heat exchanger is green and pollution-free, and good environmental and economic values are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchanger rust removal, in particular to a plate heat exchanger rust removal method. Background Art

[0002] Existing heat exchangers are mainly shell and tube heat exchangers, and there are also plate heat exchangers, plate-fin heat exchangers, spiral plate heat exchangers, and shell-and-tube heat exchangers. In the technical field of circulating water treatment systems, plate heat exchangers are used as equipment for heat exchange between cooling circulating water and production materials. During the operation of the equipment, rust will be generated in the pipeline, and the rust will be deposited on the plate heat exchanger, affecting normal use. The rust on the heat exchanger plates needs to be removed in time. After the plate heat exchanger has been in operation for about 3-5 months, the plates on the plate heat exchanger will appear dark red. The reason for this dark red color is that rust is deposited on the surface of the plates. The heat exchanger needs to be disassembled and cleaned. During the disassembly and cleaning process, the water treatment system often needs to be shut down and stopped. After cleaning, the heat exchanger needs to be installed back, which is not only time-consuming and labor-intensive, but also has a great impact on the operation of the circulating water treatment system.

[0003] In order to solve the above technical problems, it is necessary to make further improvements and develop a method to prevent rust from depositing on the plates of the plate heat exchanger and to avoid disassembling the plate heat exchanger during equipment maintenance. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a rust removal method for a plate heat exchanger, which solves the technical problem that rust is easily deposited on the existing plate heat exchanger and the plate heat exchanger needs to be disassembled for maintenance.

[0005] The present invention is achieved through the following technical solutions: A method for removing rust from a plate heat exchanger comprises the following steps: S1: Circulating water flows out of the secondary side outlet of the plate heat exchanger, and the circulating water flows to the negative electron generator driven by the lifting water pump. The negative electron generator continuously releases a large number of negative electrons into the circulating water; S2: Circulating water flows through the negative electron generator and then flows into the cooling water tower; S3: The circulating water is cooled by the cooling tower and then flows into the water storage tank; S4: The lifting water pump draws water from the water storage tank, and the drawn circulating water flows into the bag filter; S5: The bag filter filters the particulate impurities in the circulating water; S6: The circulating water treated by the bag filter flows through the negative electron generator, which continuously releases a large amount of negative electrons into the circulating water; S7: The circulating water with a large amount of negative electrons flows back to the plate heat exchanger to remove rust from the plate heat exchanger, and then steps S1 to S6 are repeated to complete the pipeline circulation.

[0006] Preferably, the cooling water tower is connected to a negative electron generator, and the negative electron generator is connected to a water supply port.

[0007] Preferably, the cooling water tower is provided with a water inlet and a water outlet, and both the water inlet and the water outlet are provided with a temperature detection device.

[0008] Preferably: the water storage tank is provided with a drain outlet, the water storage tank is connected to the negative electron generator, and the negative electron generator is connected to the water supply port.

[0009] Preferably, the water storage tank is provided with a liquid level sensor.

[0010] Preferably, the bag filter consists of a filter cartridge, a filter bag, and a cover.

[0011] Preferably, the bag filter is provided with a sewage outlet, and the sewage outlet is located at the bottom of the bag filter.

[0012] Preferably, a bypass pipe is provided before and after the bag filter, and a valve is provided on the bypass pipe.

[0013] Preferably, a sampling valve is provided on the outlet pipe of the bag filter.

[0014] Preferably: Step S1: a portion of the circulating water flowing out of the secondary side outlet of the plate heat exchanger flows into the negative electron generator; and a portion of the circulating water flows into the cooling water tower.

[0015] The patented solution of the present invention has the following beneficial effects: the technical solution of the present invention allows the circulating water to circulate in the entire pipeline through the cooperation of 2-3 negative electron generators, a lifting water pump and a bag filter. The 2-3 negative electron generators continuously release a large number of negative electrons into the circulating water, and the rust in the pipeline and the plate heat exchanger is removed by a large number of negative electrons, thereby avoiding the deposition of rust on the plates of the plate heat exchanger. When maintaining the equipment, there is no need to disassemble the plates of the plate heat exchanger or clean the plates, which greatly reduces the workload of equipment maintenance. In addition, the solution of the present invention does not use chemical agents, is green and pollution-free, and achieves good environmental and economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of Example 1 of a plate heat exchanger rust removal method proposed by the present invention; Figure 2 This is a flow chart of a second embodiment of a method for removing rust from a plate heat exchanger proposed by the present invention; Figure 3 This is a flow chart of embodiment 3 of a method for removing rust from a plate heat exchanger proposed by the present invention. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0018] The plate heat exchanger itself has a primary inlet, a primary outlet, a secondary inlet, and a secondary outlet; the primary inlet is used for the inflow of high-temperature fluid; the primary outlet is used for the outflow of high-temperature fluid after releasing heat; the secondary inlet is used for the inflow of low-temperature fluid; the secondary outlet is used for the outflow of low-temperature fluid after absorbing heat.

[0019] like Figure 1-3 As shown, the technical solution of the present invention provides three embodiments. Embodiment 1: A method for removing rust from a plate heat exchanger comprises the following steps: S1: Circulating water flows out of the secondary side outlet of the plate heat exchanger, and the circulating water flows to the negative electron generator driven by the lifting water pump. The negative electron generator continuously releases a large amount of negative electrons into the circulating water.

[0020] The negative electron generator is an SPL negative electron generator independently developed by the applicant. Its working principle is that after the equipment is powered on, a large number of negative electrons are released into the circulating water, and an electric double layer potential is quickly formed on the surface of the pipeline or equipment. The released negative electrons quickly undergo a reduction reaction with the iron ions in the circulating water, reducing the iron ions to iron atoms, and forming a coexistence of iron and water. Due to the reducing effect of the negative electrons, the formation of rust can be completely prevented. At the same time, under the action of the negative electrons, the rust that has already been generated will also be completely eliminated; when the circulating water flowing out of the plate heat exchanger is very clear, the circulating water can also flow directly into the cooling water tower without passing through the negative electron generator; or part of the circulating water can flow into the negative electron generator, and part of the circulating water can flow into the cooling water tower.

[0021] S2: The circulating water flows through the negative electron generator and then flows into the cooling water tower. Since the position of the negative electron generator is higher than the water level of the cooling water tower, the circulating water can flow into the cooling water tower under the action of gravity. The specific position where the circulating water flows into the cooling water tower is the upper part of the cooling water tower.

[0022] The cooling water tower is provided with a water inlet and a water outlet, the water inlet is at the upper part, and the water outlet is at the lower part. The water inlet and the water outlet of the cooling water tower are both provided with temperature detection devices for detecting the water temperature difference between the water inlet and the water outlet. The staff can judge the cooling effect of the cooling tower according to the water temperature difference. The cooling water tower adopts two cooling methods: natural cooling and fan cooling.

[0023] A liquid level sensor and an electric valve are installed in the cooling water tower. The liquid level sensor is used to detect the water level in the cooling water tower. When the water level is lower than the set value, the liquid level sensor transmits a signal to the electric valve, and the electric valve opens. The electric valve is also connected to another negative electron generator, and the negative electron generator is connected to the water supply port. The newly added water flows through the negative electron generator and flows into the cooling water tower. The function of the negative electron generator is to allow the newly added water to carry a large number of negative electrons, thereby improving the rust removal effect.

[0024] S3: The circulating water cooled by the cooling tower flows into the water storage tank under the action of gravity; the cooling tower is located higher than the water storage tank, so the circulating water flowing to the cooling tower will flow to the water storage tank again, and the circulating water will not stay in the cooling tower.

[0025] The water storage tank is made of stainless steel or fiberglass. There is a drain outlet at the bottom of the water storage tank. After the water storage tank has been running for several months, impurities will accumulate in the water. The circulating water can be drained through the drain outlet. The water storage tank is also equipped with a liquid level sensor to detect the water level. When the water level is higher than the set value, the liquid level sensor can send out an audible and visual alarm to remind the staff. After receiving the reminder, the staff will close the valve of the water inlet and stop replenishing water.

[0026] S4: The water pump's suction pipe extends into the water storage tank to pump water, and the pumped water flows into the bag filter.

[0027] The water storage tank is equipped with a liquid level sensor. When the water level in the water storage tank is lower than the set value, the liquid level sensor will emit an audible and visual alarm. After receiving the reminder, the staff will turn off the lifting water pump to avoid idling of the lifting water pump, which plays a role in energy saving. The lifting water pump uses a variable frequency pump, and the speed of the water pump can be adjusted to avoid excessive or insufficient water pressure, thereby improving the stability of the circulating water treatment system.

[0028] S5: The bag filter filters impurities in the circulating water.

[0029] The bag filter consists of a filter cartridge, a filter bag, and a cover. The function of the bag filter is to remove particulate impurities in the water and prevent impurities from entering the plate heat exchanger. The flow channel of the plate heat exchanger is narrow. If impurities enter the plate heat exchanger, it is easy to get clogged. Pressure detection devices are provided before and after the bag filter to detect the pressure difference before and after the bag filter. The value of the pressure difference is directly related to the degree of blockage of the bag filter. When the pressure difference value is too large, it means that the bag filter is seriously clogged and needs to be maintained immediately.

[0030] After the bag filter has been used for a long time, particulate impurities inside the bag filter will accumulate, causing the bag filter to become clogged and require maintenance and cleaning. The circulating water treatment system needs to be stopped during the cleaning. In order to allow the circulating water treatment system to continue running when the bag filter is maintained and cleaned, an additional bypass pipe is set before and after the bag filter, and the bypass pipe is equipped with a valve. When the bag filter is maintained and cleaned, if the water quality is visibly clear to the naked eye, the bypass pipe can be switched to temporary water supply. At this time, although the circulating water is not filtered by the bag filter, when the circulating water quality is visibly clear, there are very few particulate impurities in it, which will not affect the normal operation of the circulating water treatment system.

[0031] S6: The circulating water treated by the bag filter flows through the negative electron generator, which continuously releases a large number of negative electrons into the circulating water. The concentration of negative electrons around the negative electron generator is high. After the circulating water flows through the negative electron generator, the concentration of negative electrons in the circulating water increases, and the rust removal effect of the circulating water will be enhanced.

[0032] S7: When the circulating water with a large number of negative electrons flows through the plate heat exchanger, the circulating water can remove rust from the plate heat exchanger, and then repeat steps S1-S6 to complete the pipeline circulation.

[0033] The technical solution of the present invention also provides a second embodiment. The difference between the second embodiment and the first embodiment is that the water replenishment port is arranged on the water storage tank instead of the cooling water tower. Since the water storage tank is at a low position, water replenishment is more convenient.

[0034] The technical solution of the second embodiment: a method for removing rust from a plate heat exchanger, comprising the following steps: S1: Circulating water flows out of the secondary side outlet of the plate heat exchanger, and the circulating water flows to the negative electron generator driven by the lifting water pump. The negative electron generator continuously releases a large number of negative electrons into the circulating water; S2: Circulating water flows through the negative electron generator and then flows into the cooling water tower; S3: After cooling down in the cooling tower, the circulating water flows into the water storage tank, which is connected to the negative electron generator, and the negative electron generator is connected to the water supply port; S4: The lifting water pump draws water from the water storage tank, and the drawn circulating water flows into the bag filter; S5: The bag filter filters the particulate impurities in the circulating water; S6: The circulating water treated by the bag filter flows through the negative electron generator, which continuously releases a large amount of negative electrons into the circulating water; S7: The circulating water with a large amount of negative electrons flows back to the plate heat exchanger to remove rust from the plate heat exchanger, and then steps S1 to S6 are repeated to complete the pipeline circulation.

[0035] The technical solution of the present invention also provides a third embodiment: a method for removing rust from a plate heat exchanger, comprising the following steps: S1: Circulating water flows out of the secondary side outlet of the plate heat exchanger, and the circulating water flows to the negative electron generator driven by the lifting water pump. The negative electron generator continuously releases a large number of negative electrons into the circulating water; S2: Circulating water flows through the negative electron generator and then flows into the cooling water tower; S3: The circulating water is cooled by the cooling tower and then flows into the water storage tank; S4: The lifting water pump draws water from the water storage tank, and the drawn circulating water flows into the bag filter; S5: The bag filter filters the particulate impurities in the circulating water; The bag filter is provided with a sewage outlet; the sewage outlet is located at the bottom of the bag filter. When maintaining and cleaning the bag filter, the staff can first empty the sewage in the filter cartridge to avoid sewage splashing during disassembly. The bag filter outlet pipe is also provided with a sampling valve to facilitate water sampling. S6: The circulating water treated by the bag filter flows through the negative electron generator, which continuously releases a large amount of negative electrons into the circulating water; S7: The circulating water with a large amount of negative electrons flows back to the plate heat exchanger to remove rust from the plate heat exchanger, and then steps S1 to S6 are repeated to complete the pipeline circulation.

[0036] The patented solution of the present invention has the following beneficial effects: the technical solution of the present invention allows the circulating water to circulate in the entire pipeline through the cooperation of 2-3 negative electron generators, a lifting water pump and a bag filter. The 2-3 negative electron generators continuously release a large number of negative electrons into the circulating water, and the rust in the pipeline and the plate heat exchanger is removed by a large number of negative electrons, thereby avoiding the deposition of rust on the plates of the plate heat exchanger. When maintaining the equipment, there is no need to disassemble the plates of the plate heat exchanger or clean the plates, which greatly reduces the workload of equipment maintenance. In addition, the technical solution of the present invention does not use chemical agents, is green and pollution-free, and achieves good environmental and economic value.

[0037] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions may be made to these embodiments without departing from the principles of the present invention, and these changes and substitutions are also within the scope of protection of the present invention.

Claims

1. A method for removing rust from a plate heat exchanger, characterized in that: It includes the following steps: S1: Circulating water flows out of the secondary side outlet of the plate heat exchanger. Driven by the lifting water pump, the circulating water flows to the negative electron generator, which continuously releases a large number of negative electrons into the circulating water. S2: Circulating water flows through the negative electron generator and then flows into the cooling water tower; S3: The circulating water is cooled by the cooling tower and then flows into the water storage tank; S4: The lifting water pump draws water from the water storage tank, and the drawn circulating water flows into the bag filter; S5: The bag filter filters the particulate impurities in the circulating water; S6: The circulating water treated by the bag filter flows through the negative electron generator, which continuously releases a large amount of negative electrons into the circulating water; S7: The circulating water with a large amount of negative electrons flows back to the plate heat exchanger to remove rust from the plate heat exchanger, and then steps S1 to S6 are repeated to complete the pipeline circulation.

2. The rust removal method for a plate heat exchanger according to claim 1, characterized in that: The cooling water tower is connected to the negative electron generator, and the negative electron generator is connected to the water supply port.

3. The rust removal method for a plate heat exchanger according to claim 1, characterized in that: The cooling water tower is provided with a water inlet and a water outlet, and both the water inlet and the water outlet are provided with temperature detection devices.

4. The rust removal method for a plate heat exchanger according to claim 1, characterized in that: The water storage tank is provided with a drain outlet, the water storage tank is connected to the negative electron generator, and the negative electron generator is connected to the water supply outlet.

5. The plate heat exchanger rust removal method according to claim 2, characterized in that: The water storage tank is provided with a liquid level sensor.

6. The method for removing rust from a plate heat exchanger according to claim 1, wherein: The bag filter consists of a filter cartridge, a filter bag and a cover.

7. The plate heat exchanger rust removal method according to claim 1, characterized in that: The bag filter is provided with a sewage outlet, and the sewage outlet is located at the bottom of the bag filter.

8. The method for removing rust from a plate heat exchanger according to claim 1, wherein: A bypass pipe is arranged before and after the bag filter, and a valve is provided on the bypass pipe.

9. The method for removing rust from a plate heat exchanger according to claim 1, wherein: A sampling valve is provided on the outlet pipe of the bag filter.

10. The method for removing rust from a plate heat exchanger according to claim 1, wherein: Step S1: Part of the circulating water flowing out of the secondary side outlet of the plate heat exchanger flows into the negative electron generator; and part of the circulating water flows into the cooling water tower.

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