A cascade utilization system for demister flushing water

Abstract

The invention discloses a demister flushing water cascade utilization system, comprising a demister flushing water tank, a demister flushing water pump, a reuse water tank, a stirrer, a reuse water pump, a confluence trough and a drain pipe; the inlet of the demister flushing water pump is connected with the outlet of the demister flushing water tank, the outlet of the demister flushing water pump is connected with a lower flushing water pipe of a second-stage demister, an upper flushing water pipe of a second-stage demister, a lower flushing water pipe of a third-stage demister and an upper flushing water pipe of a third-stage demister; a confluence trough is arranged at the bottom of the lower end of the second-stage demister, the bottom outlet of the confluence trough is connected with the reuse water tank through a drain pipe; the inlet of the reuse water pump is connected with the outlet of the reuse water tank, the outlet of the reuse water pump is connected with the lower flushing water pipe of a first-stage demister and the upper flushing water pipe of the first-stage demister, the system can realize the demister flushing water cascade utilization in an absorption tower and reduce water consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of water saving and relates to a demister flushing water cascade utilization system. Background Art

[0002] At present, the high-efficiency ridge-type demister installed at the top outlet of the desulfurization absorption tower is generally used to achieve the purpose of separating flue gas and droplets (droplets containing slurry) after wet desulfurization of industrial flue gas. The ridge-type demister adopts the inertial interception principle, has high gas-liquid separation efficiency, and can meet the ultra-low emission requirements of industrial flue gas. However, with the increase of environmental protection equipment, the water balance of the system is difficult to maintain, and the large amount of flushing water required for flushing the demister cannot be met, causing the demister to be frequently blocked, seriously affecting the safe operation of the unit. Taking coal-fired power plants as an example, the ultra-low emission transformation of the wet desulfurization system generally increases the number of demister stages and transfer equipment, and the consumption of demister flushing water and equipment cooling water increases. In addition, the flue gas temperature at the inlet of the desulfurization system generally decreases by 30 to 50°C due to the commissioning of the low-temperature economizer, which greatly reduces the evaporation water consumption of the desulfurization system. As a result, the amount of water entering the desulfurization system increases while the amount of water consumed by the desulfurization system decreases, and the water balance is difficult to ensure. Therefore, it is necessary to develop a technology to recover and utilize the demister flushing water in stages to reduce water consumption, which is an important measure to save water and maintain water balance in the desulfurization system. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a demister flushing water cascade utilization system, which can realize the demister flushing water cascade utilization in the absorption tower and reduce water consumption.

[0004] To achieve the above-mentioned purpose, the demister flushing water cascade utilization system of the present invention comprises a demister flushing water tank, a demister flushing water pump, a recycling water tank, an agitator, a recycling water pump, a confluence trough and a drain pipe;

[0005] The inlet of the demister flushing water pump is connected with the outlet of the demister flushing water tank, and the outlet of the demister flushing water pump is connected with the lower flushing water pipe of the second-stage demister, the upper flushing water pipe of the second-stage demister, the lower flushing water pipe of the third-stage demister and the upper flushing water pipe of the third-stage demister;

[0006] A confluence trough is provided at the bottom of the lower end of the second-stage demister, and the bottom outlet of the confluence trough is connected to the recycling water tank through a drainage pipe;

[0007] The inlet of the recycling water pump is connected with the outlet of the recycling water tank, and the outlet of the recycling water pump is connected with the lower flushing water pipe of the first-stage demister and the upper flushing water pipe of the first-stage demister.

[0008] The outlet of the demister flushing water pump is connected to the second-stage demister lower flushing water pipe, the second-stage demister upper flushing water pipe, the third-stage demister lower flushing water pipe and the third-stage demister upper flushing water pipe through the demister flushing water pipe.

[0009] It also includes a water source, a first water replenishment valve and a control system; the outlet of the water source is connected to the water replenishment port of the demister flushing water tank through the first water replenishment valve, a first liquid level gauge is arranged in the demister flushing water tank, and the first liquid level gauge and the first water replenishment valve are connected to the control system.

[0010] The outlet of the recycling water pump is connected to the lower flushing water pipe of the first-stage demister and the upper flushing water pipe of the first-stage demister through the recycling water main pipe.

[0011] A stirrer is provided in the recycled water tank.

[0012] A second liquid level meter is arranged in the recycling water tank, and the second liquid level meter and the recycling water pump are connected with the control system.

[0013] The inlet of the reuse water pump is connected to the outlet of the reuse water tank through a filter.

[0014] The second-stage demister is an inverted roof structure.

[0015] The second stage demister is a ridge type structure.

[0016] The present invention has the following beneficial effects:

[0017] The demister flushing water cascade utilization system of the present invention collects most of the flushing water of the second-stage demister and the third-stage demister into the recycling water tank through the confluence trough and the drainage pipe during specific operation, and then uses the recycled water in the recycling water tank to flush the first-stage demister, so as to realize the graded cascade utilization of the demister flushing water and significantly reduce the water consumption of the desulfurization system. In addition, it should be noted that the present invention realizes the recycling and cascade utilization of the demister flushing water, so the flushing frequency and flushing time of the demister can be increased, so that the demister and the flushing water recovery system are in a moist and water-flowing state, and are not easy to be blocked. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a system diagram of the present invention;

[0019] Figure 2 It is a structural schematic diagram of embodiment 1;

[0020] Figure 3 It is a structural diagram of embodiment 2.

[0021] Among them, 1 is the demister flushing water tank, 2 is the demister flushing water pump, 3 is the demister flushing water pipe, 4 is the reuse water tank, 5 is the agitator, 6 is the filter, 7 is the reuse water pump, 8 is the reuse water pipe, 9 is the confluence trough, 10 is the drain pipe, 11 is the demister support beam, 12 is the first-stage demister, 13 is the second-stage demister, 14 is the third-stage demister, 15 is the first-stage demister lower flushing water pipe, 16 is the first-stage demister upper flushing water pipe, 17 is the second-stage demister lower flushing water pipe, 18 is the second-stage demister upper flushing water pipe, 19 is the third-stage demister lower flushing water pipe, and 20 is the third-stage demister upper flushing water pipe. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only an embodiment of a part of the present invention, not all embodiments, and is not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0023] The accompanying drawings show schematic diagrams of structures according to embodiments disclosed in the present invention. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0024] refer to Figure 1 The demister flushing water cascade utilization system of the present invention comprises a demister flushing water tank 1, a demister flushing water pump 2, a demister flushing water pipe 3, a reuse water tank 4, a stirrer 5, a filter 6, a reuse water pump 7, a reuse water pipe 8, a confluence tank 9 and a drain pipe 10;

[0025] The inlet of the demister flushing water pump 2 is connected with the outlet of the demister flushing water tank 1, and the outlet of the demister flushing water pump 2 is connected with the second-stage demister lower flushing water pipe 17, the second-stage demister upper flushing water pipe 18, the third-stage demister lower flushing water pipe 19 and the third-stage demister upper flushing water pipe 20 through the demister flushing water pipe 3, and the second-stage demister 13 is flushed through the nozzles on the second-stage demister lower flushing water pipe 17 and the second-stage demister upper flushing water pipe 18, and the third-stage demister 14 is flushed through the nozzles on the third-stage demister lower flushing water pipe 19 and the third-stage demister upper flushing water pipe 20.

[0026] The outlet of the water source is connected to the water supply port of the demister flushing water tank 1 through the first water supply valve. A first liquid level gauge is provided in the demister flushing water tank 1. The first liquid level gauge and the first water supply valve are connected to the control system to replenish process water according to the liquid level of the demister flushing water tank 1.

[0027] A confluence trough 9 is provided at the bottom of the lower end of the second-stage demister 13, and the bottom outlet of the confluence trough 9 is connected to the reuse water tank 4 through a drain pipe 10. The flushing water flowing down from the second-stage demister 13 and the third-stage demister 14 is collected through the confluence trough 9, wherein the drain pipe 10 is inserted below the liquid level of the reuse water tank 4 to prevent smoke leakage through the water seal principle.

[0028] The inlet of the reuse water pump 7 is connected with the outlet of the reuse water tank 4 through the filter 6, and the outlet of the reuse water pump 7 is connected with the first-stage demister lower flushing water pipe 15 and the first-stage demister upper flushing water pipe 16 through the reuse water mother pipe 8. The first-stage demister 12 is flushed with water sprayed from the nozzles of the first-stage demister lower flushing water pipe 15 and the first-stage demister upper flushing water pipe 16.

[0029] A stirrer 5 is provided in the reuse water tank 4 to prevent the deposition of solid particles in the reuse water; a second liquid level gauge is provided in the reuse water tank 4, and the second liquid level gauge and the reuse water pump 7 are connected to the control system. By adjusting the flushing frequency of the demister, the water inlet and outlet of the reuse water tank 4 are balanced, and the balance is appropriately adjusted by adding process water.

[0030] The main features of the present invention are:

[0031] Taking advantage of the inclined arrangement of the ridge-type (or inverted ridge-type) demister, most of the flushing water of the second-stage demister 13 and the third-stage demister 14 is collected into the reuse water tank 4 through the confluence trough 9 and the drain pipe 10, and the first-stage demister 12 is flushed with the reuse water in the reuse water tank 4, thereby realizing the graded and cascaded utilization of the demister flushing water and significantly reducing the water consumption of the desulfurization system.

[0032] The present invention inserts the drain pipe 10 below the liquid level of the recycling water tank 4, and through the water seal principle, smoke leakage is avoided while the demister flushing water is recovered.

[0033] The present invention realizes the recycling and cascade utilization of the demister flushing water, thereby increasing the flushing frequency and flushing time of the demister, and making the demister and the flushing water recovery system in a moist and water-flowing state, and not easy to be blocked.

[0034] Embodiment 1

[0035] refer to Figure 2 The second-stage demister 13 is of an inverted ridge type. The second-stage demister 13 and the third-stage demister 14 are fixed to the inner wall of the desulfurization absorption tower body through the demister support beam 11; a confluence trough 9 is arranged at the lower part of the lowest part of the inverted ridge of the second-stage demister 13 to collect the flushing water flowing down from the second-stage demister 13 and the third-stage demister 14.

[0036] Embodiment 2

[0037] refer to Figure 3 The second-stage demister 13 is of ridge type, and a demister support beam 11 is separately provided; at the lowest point on both sides of the ridge of the second-stage demister 13, on the side or bottom of the demister support beam 11, a confluence trough 9 is provided to collect the flushing water flowing down from the second-stage demister 13 and the third-stage demister 14.

Claims

1. A cascade utilization system for demister flushing water, characterized in that: It comprises a demister flushing water tank (1), a demister flushing water pump (2), a recycling water tank (4), an agitator (5), a recycling water pump (7), a confluence trough (9) and a drainage pipe (10); The inlet of the demister flushing water pump (2) is connected to the outlet of the demister flushing water tank (1), and the outlet of the demister flushing water pump (2) is connected to the second-stage demister lower flushing water pipe (17), the second-stage demister upper flushing water pipe (18), the third-stage demister lower flushing water pipe (19) and the third-stage demister upper flushing water pipe (20); A confluence trough (9) is provided at the bottom of the lower end of the second-stage demister (13), and a bottom outlet of the confluence trough (9) is connected to a recycling water tank (4) through a drainage pipe (10); The inlet of the recycling water pump (7) is connected to the outlet of the recycling water tank (4), and the outlet of the recycling water pump (7) is connected to the lower flushing water pipe (15) of the first-stage demister and the upper flushing water pipe (16) of the first-stage demister; The outlet of the demister flushing water pump (2) is connected to the second-stage demister lower flushing water pipe (17), the second-stage demister upper flushing water pipe (18), the third-stage demister lower flushing water pipe (19) and the third-stage demister upper flushing water pipe (20) through the demister flushing water pipe (3); It also includes a water source, a first water replenishment valve and a control system; the outlet of the water source is connected to the water replenishment port of the demister flushing water tank (1) through the first water replenishment valve, a first liquid level gauge is arranged in the demister flushing water tank (1), and the first liquid level gauge and the first water replenishment valve are connected to the control system.

2. The demister flushing water cascade utilization system according to claim 1, characterized in that: The outlet of the recycling water pump (7) is connected to the first-stage demister lower flushing water pipe (15) and the first-stage demister upper flushing water pipe (16) through the recycling water main pipe (8).

3. The demister flushing water cascade utilization system according to claim 1, characterized in that: A stirrer (5) is arranged in the recycled water tank (4).

4. The demister flushing water cascade utilization system according to claim 1, characterized in that: A second liquid level meter is arranged in the recycling water tank (4), and the second liquid level meter and the recycling water pump (7) are connected to the control system.

5. The demister flushing water cascade utilization system according to claim 1, characterized in that: The inlet of the recycling water pump (7) is connected to the outlet of the recycling water tank (4) through the filter (6).

6. The demister flushing water cascade utilization system according to claim 1, characterized in that: The second-stage demister (13) is of an inverted ridge structure.

7. The demister flushing water cascade utilization system according to claim 1, characterized in that: The second stage demister (13) is a ridge type structure.

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