Cooling water circulation system for mechanical seal of evaporation pump

Abstract

The utility model discloses a mechanical seal cooling water circulation system of an evaporation pump, and belongs to the technical field of mechanical seal cooling of pumps. According to the mechanical seal cooling water circulation system of the evaporation pump, the mechanical seal water tank for feeding water to the evaporation pump is arranged higher than the evaporation pump, cooling water is fed into the evaporation pump through self pressure, and the evaporation pump is sequentially connected with the mechanical seal water return pipe, the soft water pool and the soft water pump at the same time. The soft water pump can pump water recycled into the soft water pool into the mechanical seal water tank again to achieve circulation of cooling water. Meanwhile, the mechanical seal water tank is provided with an electrical loop comprising a field lamp, a main control lamp and a DCS, and the on-off of the electrical loop depends on the height of the water level of the mechanical seal water tank. According to the system, water is fed to the evaporation pump through self pressure, the pressure of cooling water is stable and small in volatility, meanwhile, water shortage can be avoided by monitoring the water level of the mechanical seal water tank, and therefore effective protection on the mechanical seal of the evaporation pump is achieved, and stable operation of the evaporation pump is facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of cooling the mechanical seal of a pump, and in particular relates to a cooling water circulation system for the mechanical seal of an evaporation pump. Background Art

[0002] The statements in this section are merely intended to provide background information related to the technical solution of the present application to aid understanding, and they do not necessarily constitute prior art for the technical solution of the present application.

[0003] In the production of alumina (AO), evaporation is an important production process to maintain liquid balance, evaporate the mother liquor to a concentration that meets production requirements, and remove impurities accumulated during the production process. It has an important impact on the stability of the production indicators of the next process of dissolution and slurry preparation. Taking the Bayer process as an example, the Bayer process requires about 3-4 tons of water to evaporate for every ton of AO produced. The evaporation process consumes a lot of heat energy, accounting for about 30-45% of the energy consumed by the Bayer process. At present, domestic alumina plants all use six-effect or seven-effect falling film evaporators. Each evaporator unit contains more than 20 evaporation pumps. The sealing method of the evaporation pump equipment is mechanical seal. The stable operation of pump equipment is crucial to the stability of the unit, and the maintenance of mechanical seals is the top priority. In order to maintain the stable operation of the evaporator pump unit, it is usually necessary to cool the mechanical seal in the evaporator pump by water. The commonly used method of adding cooling water is to pump cooling water into the evaporator pump. However, the pressure is unstable and fluctuates greatly through simple pumping, which will cause mutual influence between different pump equipment in the unit. At the same time, when cooling water cannot be added in time, the mechanical seal will burn out, affecting the normal operation of the unit. Utility Model Content

[0004] In view of the problems in the prior art, the utility model proposes an evaporator pump mechanical seal cooling water circulation system and circulation method. The specific technical scheme is as follows:

[0005] A cooling water circulation system for an evaporator pump mechanical seal comprises a soft water tank, a soft water pump, a float valve, a machine seal water tank, a machine seal water pipe, an evaporator pump, a machine seal return pipe, a plurality of relays KA, a master control lamp, a site lamp and an electrical circuit, wherein the machine seal water tank is connected with a machine seal water pipe below, the machine seal water pipe is connected with the evaporator pump, the machine seal return pipe and the soft water tank in sequence, and the machine seal water tank is connected with a pipeline above, the pipeline is connected with the soft water tank through the soft water pump, and the float valve is placed in the machine seal water tank; the machine seal water tank is located at least 25 meters above the evaporator pump; an electrical circuit is connected between point B and point C on the machine seal water tank, point B is located near the top of the machine seal water tank, and point C is located below point B, a switch A is provided between point B and point C in the electrical circuit, the relay KA, the master control lamp and the site lamp are arranged on the electrical circuit, wherein the master control lamp and the site lamp are arranged in parallel, and at least one relay KA is provided in series on the branch where the master control lamp and the site lamp are located.

[0006] Furthermore, a DCS is also arranged on the electrical circuit, and the DCS contains at least one relay KA, and the DCS branch is arranged in parallel with the master control lamp branch and the field lamp branch.

[0007] Compared with the prior art, the beneficial technical effects of the utility model are:

[0008] (1) The cooling water of the utility model flows into the mechanical seal pipeline of the evaporator pump from a high place by self-pressure. The pressure generated by the height difference is stable and has small fluctuation, which is conducive to the normal operation of the mechanical seal, thereby ensuring the normal operation of the evaporator pump and the unit;

[0009] (2) The utility model sets an electrical circuit for monitoring the water level on the mechanical seal water tank, and can realize water shortage alarm through indicator lights and DCS display. Both the on-site operator and the manager at the remote control end can monitor the water tank liquid level in real time and remotely without obstacles. The process is simple, which ensures that the mechanical seal cooling water of the evaporator pump is always controlled at a reasonable liquid level, ensures the normal water use of the mechanical seal, and ultimately ensures the stable operation of the evaporator unit. At the same time, it also reduces the frequency of mechanical seal damage and reduces the consumption of spare parts. The utility model has obvious technical and economic advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic diagram of the flow of the cooling water circulation system of the evaporation pump mechanical seal of the utility model.

[0011] Among them, soft water tank-1, soft water pump-2, float valve-3, machine seal water tank-4, machine seal water pipe-5, evaporator pump-6, machine seal return pipe-7, relay KA-8, main control light-9, site light-10, DCS-11, electrical circuit-12. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solution and advantages of the utility model more clear, the evaporation pump mechanical seal cooling water circulation system of the present application is described in detail below in combination with the embodiments and drawings. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0013] In one embodiment, a mechanical seal water tank 4 in an evaporator pump mechanical seal cooling water circulation system is located 26 meters above the evaporator pump 6, and a mechanical seal water pipe 5 is connected below the mechanical seal water tank 4. The mechanical seal water pipe 5 is connected to the evaporator pump 6, the mechanical seal return pipe 7, and the soft water tank 1 in sequence. A pipeline is connected above the mechanical seal water tank 4, and the pipeline is connected to the soft water pump 2. The soft water pump 2 pumps water from the soft water tank 1 into the mechanical seal water tank 5 through the pipeline. A float valve 3 is placed in the mechanical seal water tank, and the float valve 3 is automatically controlled to prevent water from bubbling. An electrical circuit 12 is connected between point B and point C on the mechanical seal water tank 4, and point B is located near the top of the mechanical seal water tank 4, and point C is located below point B. The electrical circuit 12 is provided with a switch A between point B and point C. When the liquid level is higher than point B, switch A connects the electrical circuit 12 to form a passage. When the liquid level is lower than point B, switch A disconnects the electrical circuit 12 to break the circuit. The master light 9 is connected in series with a relay KA-1, the field light 10 is connected in series with a relay KA-2, and the DCS is connected in series with a relay KA-3. The field light 10, the master light 9, the relay KA, and the DCS11 are all arranged on the electrical circuit 12, wherein the master light 9 is connected in parallel with the branch of the relay KA-1, the field light 10 is connected in parallel with the branch of the relay KA-2, and the DCS11 is connected in parallel with the branch of the relay KA-3. When the electrical circuit 12 is connected, the connection status of the field light 10 and the master light 9 is on, and the connection status of the DCS (connected to the computer) is green. When the electrical circuit is broken, the breaking status of the field light and the master light is not luminous, and the breaking status of the DCS (connected to the computer) is red flashing. The specific locations of point B and point C of the machine seal water tank 4 are determined according to the requirements and conditions such as the evaporator pump unit and the capacity of the machine seal water tank.

[0014] When the loop system is enabled:

[0015] First, start the soft water pump 2 to send the soft water in the soft water tank 1 to the mechanical seal water tank 4 to fill the tank. The float valve 3 automatically controls the mechanical seal water tank 4 to prevent water from bubbling. The soft water passes through the mechanical seal return pipe 7 below the mechanical seal water tank 4 and reaches the evaporation pump 6 by gravity, i.e., self-pressure. After cooling the mechanical seal of the evaporation pump 6, it enters the soft water tank 1 through the mechanical seal return pipe 7 to realize the circulation of cooling water.

[0016] When the water level of the machine-sealed water tank 4 is higher than point B, switch A is connected, the electrical circuit 12 is in the on-line state, the main control light 9 and the on-site light 10 connected to the relay KA are on to show the on-line state, and DCS11 is displayed green on the computer. When the water level of the machine-sealed water tank 4 is lower than point B, it is in the off-circuit state, then switch A is disconnected, the electrical circuit 12 is in the off-circuit state, the main control light 9 and the on-site light 10 connected to the relay KA are off to show the off-circuit state, and DCS11 is displayed red on the computer and flashes to alarm. Operators or managers can add soft water to the soft water pool according to the water level monitoring situation to prevent the water level of the machine-sealed water tank 4 from being too low.

Claims

1. An evaporative pump mechanical seal cooling water circulation system, characterized in that: The invention comprises a soft water tank (1), a soft water pump (2), a float valve (3), a mechanical seal water tank (4), a mechanical seal water pipe (5), an evaporation pump (6), a mechanical seal water return pipe (7), a plurality of relays KA (8), a main control lamp (9), a field lamp (10) and an electrical circuit (12), wherein the mechanical seal water tank (4) is connected with the mechanical seal water pipe (5) below, the mechanical seal water pipe (5) is connected with the evaporation pump (6), the mechanical seal water return pipe (7) and the soft water tank (1) in sequence, and a pipeline is connected with the mechanical seal water tank (4) above, the pipeline is connected with the soft water tank (1) through the soft water pump (2), and the float valve (3) is placed on the mechanical seal water tank (4). ); the machine-sealed water tank (4) is located at least 25 meters above the evaporation pump (6); an electrical circuit (12) is connected between point B and point C on the machine-sealed water tank (4), point B is located near the top of the machine-sealed water tank, and point C is located below point B, a switch A is provided between point B and point C in the electrical circuit (12), the relay KA (8), the main control light (9), and the on-site light (10) are provided on the electrical circuit (12), wherein the main control light (9) and the on-site light (10) are provided in parallel, and at least one relay KA is provided in series on the branch where the main control light (9) and the on-site light (10) are located.

2. The evaporation pump mechanical seal cooling water circulation system according to claim 1, characterized in that: A DCS (11) is also provided on the electrical circuit (12), and the DCS (11) includes at least one relay KA. The branch of the DCS (11) is connected in parallel with the branch where the master control lamp (9) is located and the branch where the field lamp (10) is located.

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