A system and method for recycling demister flushing water

Abstract

This invention discloses a demister flushing water recycling system and method. The outlet of the demister flushing water tank is connected to the inlet of the demister flushing water pump, and the outlet of the recycled water tank is connected to the inlet of the recycled water pump. The outlet of the recycled water pump and the outlet of the demister flushing water pump are connected to one end of the clarifier flushing water valve and the demister flushing water pipe through a parallel pipe. The other end of the clarifier flushing water valve is connected to the clarifier flushing water tank. The top opening of the demister flushing water collection tank faces the lower end of the demister. The bottom outlet of the demister flushing water collection tank is connected to one end of the collection tank drain pipe, and the other end of the collection tank drain pipe is inserted into the clarifier flushing water tank. The top of the clarifier flushing water tank is provided with a clarifier flushing water overflow trough, and the outlet of the clarifier flushing water overflow trough is connected to the recycled water tank. This system and method can realize the recycling of demister flushing water in the absorption tower, reducing water consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of water conservation and relates to a defogger flushing water recycling system and method. Background Art

[0002] Desulfurization absorption towers are generally equipped with high-efficiency ridge-type demisters. However, after the ultra-low emission transformation, the water balance of the desulfurization system is difficult to ensure. The only way is to reduce the flushing frequency of the demister, which is the largest water consumption equipment in the desulfurization system, which leads to frequent blockage and collapse of the demister, seriously threatening the safe operation of the unit. Therefore, it is necessary to develop a technology for recycling the flushing water of the demister in the absorption tower, increase the flushing frequency of the demister, or even flush it continuously, to completely solve the water balance problem of the desulfurization system, so that the demister can operate efficiently and stably, and at the same time realize the water consumption of the unit. 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 recycling system and method, which can realize the recycling of demister flushing water in an absorption tower and reduce water consumption.

[0004] To achieve the above-mentioned purpose, the demister flushing water recycling system of the present invention comprises a demister flushing water tank, a clarifying water tank, a recycling water tank, a demister flushing water collecting tank, a collecting tank drain pipe, a recycling water pump and a demister flushing water pipe;

[0005] The outlet of the demister flushing water tank is connected to the inlet of the demister flushing water pump, the outlet of the reuse water tank is connected to the inlet of the reuse water pump, the outlet of the reuse water pump and the outlet of the demister flushing water pump are connected to one end of the clear water tank flushing water valve and the demister flushing water pipe through a pipeline, the other end of the clear water tank flushing water valve is connected to the clear water tank, the top opening of the demister flushing water collecting tank is directly opposite to the lower end of the demister, the bottom outlet of the demister flushing water collecting tank is connected to one end of the collecting tank drain pipe, and the other end of the collecting tank drain pipe is inserted into the clear water tank;

[0006] A clarifying water tank cofferdam overflow trough is arranged on the top of the clarifying water tank, and an outlet of the clarifying water tank cofferdam overflow trough is connected with the recycled water tank.

[0007] A recycling water shut-off valve is provided at the outlet of the recycling water pump.

[0008] A demister flushing water shut-off valve is provided at the outlet of the demister flushing water pump.

[0009] The bottom outlet of the clarified water tank is divided into two routes, one of which is connected to the clarified water tank underflow pump, and the other is connected to the desulfurization island drainage pit.

[0010] A clarified water tank underflow pump inlet valve is arranged between the bottom outlet of the clarified water tank and the clarified water tank underflow pump.

[0011] A clarified water tank drain valve is provided between the bottom outlet of the clarified water tank and the desulfurization island drainage pit.

[0012] A recycling water tank agitator and a recycling water tank level gauge are provided in the recycling water tank.

[0013] The outlet of the overflow trough of the clarified water tank cofferdam is connected to the recycled water tank through an overflow water pipe.

[0014] A method for recycling flushing water of a desulfurization absorption tower demister comprises the following steps:

[0015] Open the flushing water valve of the clarified water tank, and inject water into the clarified water tank through the demister flushing water pump until the liquid level in the clarified water tank is higher than the designed liquid level, and then close the flushing water valve of the clarified water tank;

[0016] Open the defogger flushing pump and flush the defogger intermittently;

[0017] The flushing water after flushing the demister flows through the gap between the inclined blades of the demister, and is directed to the demister flushing water collection tank, and flows by gravity to the clarified water tank;

[0018] When the clarified water tank reaches the highest liquid level, it overflows into the reuse water tank through the clarified water tank cofferdam overflow tank;

[0019] Turn off the demister flushing water pump, turn on the recycled water pump, and start flushing the demister with recycled water.

[0020] The present invention has the following beneficial effects:

[0021] During specific operation, the demister flushing water recycling system and method described in the present invention first injects water into the clarified water tank through the demister flushing water pump until the liquid level in the clarified water tank is higher than the designed liquid level, and then uses the clarified water tank to flush the demister, wherein the demister flushing water is collected into the clarified water tank through the demister flushing water collection tank, and the clarified water is circulated to flush the demister, so as to achieve the purpose of recycling the demister flushing water, solve the problem of water balance of the unit desulfurization system, and reduce water consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a system diagram of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the arrangement of the demister flushing water collection tank 4 in the first embodiment;

[0024] Figure 3 It is a structural schematic diagram of the arrangement of the demister flushing water collection tank 4 in the second embodiment.

[0025] Among them, 1 is the demister flushing water tank, 2 is the clarified water tank, 3 is the recycled water tank, 4 is the demister flushing water collecting tank, 5 is the collecting tank drain pipe, 6 is the demister flushing water pump, 7 is the demister flushing water shut-off valve, 8 is the clarified water tank flushing water valve, 9 is the clarified water tank cofferdam overflow tank, 10 is the clarified water tank underflow pump, 11 is the clarified water tank underflow pump inlet valve, 12 is the clarified water tank vent valve, 13 is the desulfurization island drainage pit, 14 is the overflow water pipe, 15 is the recycled water tank agitator, 16 is the recycled water tank level gauge, 17 is the recycled water pump, 18 is the recycled water shut-off valve, 19 is the demister support beam, 20 is the demister, and 21 is the demister flushing water pipe. DETAILED DESCRIPTION

[0026] 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.

[0027] 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.

[0028] refer to Figure 1 The demister flushing water recycling system of the present invention comprises a demister flushing water tank 1, a clarified water tank 2, a recycled water tank 3, a demister flushing water collecting tank 4 and a collecting tank drain pipe 5;

[0029] The outlet of the demister flushing water tank 1 is connected with the inlet of the demister flushing water pump 6, the outlet of the reuse water tank 3 is connected with the inlet of the reuse water pump 17, the outlet of the reuse water pump 17 and the outlet of the demister flushing water pump 6 are connected with one end of the clear water tank flushing water valve 8 and the demister flushing water pipe 21 through a pipeline, a reuse water shut-off valve 18 is provided at the outlet of the reuse water pump 17, a demister flushing water shut-off valve 7 is provided at the outlet of the demister flushing water pump 6, the other end of the clear water tank flushing water valve 8 is connected with the clear water tank 2, the top opening of the demister flushing water collecting tank 4 is directly opposite to the lower end of the demister 20, the bottom outlet of the demister flushing water collecting tank 4 is connected with one end of the collecting tank drain pipe 5, and the other end of the collecting tank drain pipe 5 is inserted into the clear water tank 2;

[0030] A clarified water tank cofferdam overflow trough 9 is provided on the top of the clarified water tank 2 , and an outlet of the clarified water tank cofferdam overflow trough 9 is connected to the recycled water tank 3 via an overflow water pipe 14 .

[0031] The bottom outlet of the clarified water tank 2 is divided into two routes, one of which is connected to the clarified water tank underflow pump 10 through the clarified water tank underflow pump inlet valve 11, and the other is connected to the desulfurization island drainage pit 13 through the clarified water tank vent valve 12.

[0032] A recycling water tank agitator 15 and a recycling water tank liquid level meter 16 are arranged in the recycling water tank 3 .

[0033] The method for recycling flushing water of a desulfurization absorption tower demister of the present invention comprises the following steps:

[0034] Before starting the system, close the recycled water shut-off valve 18, open the demister flushing water shut-off valve 7, and close the clarified water tank underflow pump inlet valve 11 and the clarified water tank vent valve 12.

[0035] Open the clear water tank flushing water valve 8, and inject water into the clear water tank 2 through the demister flushing water pump 6 until the liquid level in the clear water tank 2 is higher than the designed liquid level, and then close the clear water tank flushing water valve 8, wherein the designed liquid level is higher than the liquid column obtained by adding the lowest point of the collecting tank drain pipe 5 inserted into the clear water tank 2 to the maximum flue gas pressure in the absorption tower;

[0036] Turn on the defogger flushing water pump 6 and intermittently flush the defogger 20;

[0037] The flushing water after flushing the demister 20 flows through the gap between the inclined blades of the demister 20, and is guided to the demister flushing water collecting tank 4, and flows to the clear water tank 2 through the collecting tank drain pipe 5. The collecting tank drain pipe 5 is inserted below the liquid level of the clear water tank 2, which can play a water seal role to prevent the flue gas in the absorption tower from escaping to the clear water tank 2;

[0038] When the clarified water tank 2 reaches the highest liquid level, the clarified water overflows to the reuse water tank 3 through the clarified water tank cofferdam overflow trough 9 and overflow pipe 14;

[0039] Close the demister flushing water pump 6 and the demister flushing water shut-off valve 7, open the recycled water shut-off valve 18 and the recycled water pump 17, and start flushing the demister 20 with recycled water.

[0040] It should be noted that the demister 20 is flushed by recycling the recycled water in an intermittent flushing manner or a continuous flushing manner.

[0041] When the liquid level of the reuse water tank 3 is lower than the minimum liquid level, water is directly added to the reuse water tank 3 to make the reuse water flushing system reach dynamic balance, that is, the demister flushing water pump 6 is started, and the demister 20 is flushed with the demister 20 flushing water to replenish the flushing water volume of the reuse water tank 3, so that the reuse water flushing system reaches dynamic balance.

[0042] In addition, it is necessary to regularly open the clarified water tank underflow pump inlet valve 11, flush the desulfurization system pipelines and pumps through the clarified water tank underflow pump 10, reduce the solid content of the water in the clarified water tank 2, and achieve dynamic balance.

[0043] At the same time, it is necessary to regularly open the clear water tank drain valve 12 to regularly drain the water with high solid content at the bottom of the clear water tank 2 to the desulfurization island drainage pit 13 to reduce the solid content in the water of the clear water tank 2 and achieve dynamic balance.

[0044] Embodiment 1

[0045] refer to Figure 2 The first-layer demister 20 and the third-layer demister 20 are of ridge-type structure and are arranged on the bottom-layer demister support beam 19. The second-layer demister 20 are of inverted ridge-type structure and are arranged together with the third-layer demister 20 on the upper demister support beam 19. The demister flushing water collection tank 4 is arranged on the side or bottom of the bottom-layer demister support beam 19.

[0046] Embodiment 2

[0047] refer to Figure 3 The three-layer demisters 20 are all ridge-type structures and are respectively arranged on the three-layer demister support beams 19; the demister flushing water collection tank 4 is arranged on the side or bottom of the bottom demister support beam 19.

[0048] The main features of the present invention are:

[0049] The present invention utilizes the demister flushing water collection tank 4 to collect the demister 20 flushing water to the clarified water tank 2, and the clarified clean water is circulated to flush the demister 20, and the turbid water at the bottom of the clarified water tank 2 flushes the desulfurization system pipelines and pumps or is discharged to the desulfurization island drainage pit 13, so as to achieve the purpose of recycling the demister 20 flushing water in the simplest and feasible way, solve the water balance problem that plagues most units of desulfurization systems, and obtain the following effects:

[0050] When the demister 20 is flushed in an intermittent manner, the present invention can increase the frequency of flushing the demister 20, reduce the risk of clogging of the demister 20, and reduce the overall water consumption of the desulfurization system.

[0051] When the demister 20 is flushed in a continuous flushing manner, the present invention completely solves the risk of clogging of the demister 20 and reduces the overall water consumption of the desulfurization system. Since the flue gas is continuously washed during the continuous flushing of the demister 20, the dust in the flue gas can be significantly reduced.

Claims

1. A demister flushing water recycling system, characterized in that: It comprises a demister flushing water tank (1), a clarified water tank (2), a recycled water tank (3), a demister flushing water collecting tank (4), a collecting tank drain pipe (5), a recycled water pump (17) and a demister flushing water pipe (21); The outlet of the demister flushing water tank (1) is connected to the inlet of the demister flushing water pump (6), the outlet of the recycling water tank (3) is connected to the inlet of the recycling water pump (17), the outlet of the recycling water pump (17) and the outlet of the demister flushing water pump (6) are connected to one end of the clear water tank flushing water valve (8) and the demister flushing water pipe (21) through a pipeline, the other end of the clear water tank flushing water valve (8) is connected to the clear water tank (2), the top opening of the demister flushing water collecting tank (4) is directly opposite to the lower end of the demister (20), the bottom outlet of the demister flushing water collecting tank (4) is connected to one end of the collecting tank drain pipe (5), and the other end of the collecting tank drain pipe (5) is inserted into the clear water tank (2); A clarified water tank cofferdam overflow trough (9) is provided on the top of the clarified water tank (2), and an outlet of the clarified water tank cofferdam overflow trough (9) is connected to the recycled water tank (3); A recycling water shut-off valve (18) is provided at the outlet of the recycling water pump (17); A demister flushing water shut-off valve (7) is provided at the outlet of the demister flushing water pump (6).

2. The demister flushing water recycling system according to claim 1, characterized in that: The bottom outlet of the clarified water tank (2) is divided into two paths, one of which is connected to the clarified water tank underflow pump (10), and the other is connected to the desulfurization island drainage pit (13).

3. The demister flushing water recycling system according to claim 2, characterized in that: A clarified water tank underflow pump inlet valve (11) is provided between the bottom outlet of the clarified water tank (2) and the clarified water tank underflow pump (10).

4. The demister flushing water recycling system according to claim 2, characterized in that: A clear water tank drain valve (12) is provided between the bottom outlet of the clear water tank (2) and the desulfurization island drainage pit (13).

5. The demister flushing water recycling system according to claim 1, characterized in that: A recycling water tank agitator (15) and a recycling water tank liquid level meter (16) are arranged in the recycling water tank (3).

6. The demister flushing water recycling system according to claim 1, characterized in that: The outlet of the overflow trough (9) of the clarified water tank cofferdam is connected to the recycled water tank (3) via an overflow water pipe (14).

7. A method for recycling flushing water of a desulfurization absorption tower demister, characterized in that: The demister flushing water recycling system according to claim 1 comprises the following steps: Open the clear water tank flushing water valve (8), and inject water into the clear water tank (2) through the demister flushing water pump (6) until the liquid level in the clear water tank (2) is higher than the designed liquid level, and then close the clear water tank flushing water valve (8); Turn on the demister flushing water pump (6) to intermittently flush the demister (20); The flushing water after flushing the demister (20) is directed to the demister flushing water collection tank (4) through the gaps between the inclined blades of the demister (20), and flows by gravity into the clarified water tank (2); When the clarified water tank (2) reaches the highest liquid level, the clarified water overflows into the recycled water tank (3) through the clarified water tank cofferdam overflow tank (9); The demister flushing water pump (6) is turned off, and the recycled water pump (17) is turned on to start flushing the demister (20) with the recycled water.

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