Absorption tower for flue gas desulfurization

Abstract

The utility model relates to the technical field of desulfurization, in particular to an absorption tower for flue gas desulfurization, which comprises an absorption tower body, a slurry spray pipe arranged in the absorption tower body, a slurry tank below the slurry spray pipe, a slurry pump communicated between the slurry tank and the slurry spray pipe, and a demister arranged at the top of the absorption tower. At least two layers of defoaming nets are arranged above the slurry tank, a plurality of defoaming rods are vertically arranged at the bottoms of the defoaming nets, and flushing pipes are arranged above and below the demister. The utility model can solve the problem that the liquid level measurement is influenced by the foaming of the slurry.

Description

Technical Field

[0001] The utility model relates to the technical field of desulfurization, in particular to an absorption tower for flue gas desulfurization. Background Art

[0002] Flue gas desulfurization (FGD) refers to the removal of sulfur oxides from flue gas or other industrial waste gas. In FGD technology, according to the type of desulfurizer, it can be divided into the following five methods: calcium method based on CaCO3 (limestone), magnesium method based on MgO, sodium method based on Na2SO3, ammonia method based on NH3, and organic alkali method based on organic alkali. According to the dry and wet state of the absorbent and the desulfurization product in the desulfurization process, the desulfurization technology can be divided into wet method, dry method and semi-dry (semi-wet) method. The wet FGD technology uses a solution or slurry containing an absorbent to desulfurize and treat the desulfurization product in a wet state.

[0003] Among them, the wet desulfurization process based on limestone is the most widely used desulfurization technology. Its working principle is: limestone powder is added with water to make slurry, and the slurry pool at the bottom of the absorption tower is pumped to the middle of the absorption tower to spray the flue gas entering from the bottom of the absorption tower. The slurry is fully contacted and mixed with the flue gas as an absorbent. The sulfur dioxide in the flue gas reacts with the calcium carbonate in the slurry and the air blown in from the bottom of the tower to form calcium sulfate. After the calcium sulfate reaches a certain saturation, it crystallizes to form dihydrate gypsum. The desulfurized flue gas is discharged after the mist droplets are removed by the demister at the top of the absorption tower.

[0004] The absorption tower uses a level gauge to measure the slurry level, which is calculated based on the differential pressure measured by the level gauge and the slurry density. However, during operation, the slurry will bubble. Due to the slurry bubbling, the actual liquid level is higher than the level displayed by the system, which in turn causes the control system to fail to take effective measures in time, and overflow and other problems are prone to occur, resulting in reduced desulfurization efficiency, reduced gypsum quality, and even accidents. Utility Model Content

[0005] The utility model aims to provide an absorption tower for flue gas desulfurization to solve the problem that slurry foaming affects liquid level measurement.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] An absorption tower for flue gas desulfurization comprises an absorption tower body. A slurry spray pipe is arranged in the absorption tower body. A slurry pool is provided below the slurry spray pipe. A slurry pump is connected between the slurry pool and the slurry spray pipe. A demister is arranged on the top of the absorption tower. At least two layers of defoaming nets are arranged above the slurry pool. A plurality of defoaming rods are vertically arranged at the bottom of the defoaming net. Flushing pipes are arranged above and below the demister.

[0008] Preferably, as an improvement, the defoaming net is hollow inside, the defoaming net is connected to a water supply pipe, and the defoaming net is connected to a plurality of defoaming nozzles.

[0009] Preferably, as an improvement, the defoaming net is provided with two layers, and the mesh holes of the two layers of defoaming net are staggered.

[0010] Preferably, as an improvement, the defoaming rods on the two layers of defoaming nets are also staggered.

[0011] Preferably, as an improvement, the flushing pipe and the defoaming net share a water supply pipe.

[0012] Preferably, as an improvement, an agitator is installed in the slurry pool, and the agitator is arranged at the bottom of the slurry pool.

[0013] Preferably, as an improvement, agitators are arranged on both sides of the slurry pool, and at least two agitators are arranged on the side of the slurry pool where the slurry pump is arranged, and the agitators and the slurry pump are staggered.

[0014] Preferably, as an improvement, the flushing pipe includes a circular flushing pipe rack and a plurality of flushing nozzles installed on the flushing pipe rack, the flushing nozzles are aligned with the channel of the demister, and the middle part of the flushing pipe rack of the flushing pipe below the demister protrudes upward.

[0015] The principles and beneficial effects of this scheme are:

[0016] 1. This solution sets a defoaming net above the slurry pool of the absorption tower, and sets a defoaming rod vertically at the bottom of the defoaming net. When the bubbles generated by the slurry in the slurry pool collide with the defoaming net under the stirring action, they can be squeezed and broken; in addition, the vertically set defoaming rod can also directly puncture the bubbles, thereby achieving defoaming. This solution completes defoaming under the joint action of the defoaming net and the defoaming rod, and the defoaming effect is good. After defoaming, it is easy to measure the liquid level of the slurry, thereby improving the accuracy of the slurry level measurement.

[0017] 2. Based on the defoaming net and defoaming rod, this solution also sets the defoaming net as a hollow structure and connects it to a water supply pipe. The process water in the production process is connected to the defoaming net and sprayed from the defoaming nozzle to the surface of the slurry to defoam. Under the defoaming effect of the defoaming net and defoaming rod, combined with the water spraying effect, the defoaming effect can be effectively improved.

[0018] 3. Furthermore, the present invention arranges the defoaming net into two layers, and the mesh holes and defoaming rods of the two layers of defoaming net are staggered, which can produce a double defoaming effect compared to only one layer, further improving the defoaming effect.

[0019] 4. This solution sets flushing pipes above and below the demister to flush the demister, which can effectively extend the service life of the demister. In addition, the flushing water from the flushing pipes that impacts the slurry surface may also cause bubbles to be generated, but since this solution sets at least two layers of defoaming nets above the slurry pool, the impact of the flushing water can be buffered on the defoaming nets, thereby reducing the bubbles generated by the impact of the flushing water.

[0020] 5. In this scheme, the middle part of the flushing pipe rack of the flushing pipe below the demister bulges upward so that its edge is lower than the middle part, which can play a certain guiding role for the flushing water, so that most of the flushing water falls along the edge of the flushing pipe rack and then falls along the inner wall of the absorption tower, which can effectively reduce the impact on the slurry liquid surface and control the generation of bubbles.

[0021] 6. The flushing pipe and the defoaming net share a water supply pipe. In actual use, the process water outside the water supply pipe is supplied to the defoaming nozzle for spraying defoaming on the one hand, and to the flushing pipe for flushing the demister on the other hand.

[0022] 7. Placing the agitator at the bottom of the slurry pool can effectively prevent the slurry from settling; in addition, at least two agitators are arranged on the side where the slurry pump is arranged, which can enhance the stirring of the slurry at the slurry pump and facilitate the slurry pump to pump the slurry. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of an embodiment of the utility model.

[0024] Figure 2 It is a schematic diagram of the structure of the defoaming net in the embodiment of the utility model.

[0025] Figure 3 It is a schematic diagram of the structure of the baffle demister in the embodiment of the utility model.

[0026] Figure 4 It is a structural schematic diagram of a flushing pipe rack of a flushing pipe below the demister in an embodiment of the utility model. DETAILED DESCRIPTION

[0027] The following is further described in detail through specific implementation methods:

[0028] The figure marks in the drawings of the specification include: absorption tower body 1, slurry spray pipe 11, slurry pump 12, flue gas inlet 13, slurry pool 2, agitator 21, defoaming net 22, defoaming rod 221, defoaming nozzle 222, demister 3, flushing pipe 31, water supply pipe 32, channel 33, flushing pipe rack 34.

[0029] Embodiment 1:

[0030] like Figure 1As shown, an absorption tower for flue gas desulfurization includes an absorption tower body 1, in which a plurality of slurry spray pipes 11 are installed, and the plurality of slurry spray pipes 11 are arranged in a staggered manner. In this embodiment, the slurry spray pipes 11 are four layers. Below the slurry spray pipes 11 is a slurry pool 2, and a slurry pump 12 is connected between the slurry pool 2 and the slurry spray pipes 11. The slurry pump 12 is used to pump the slurry in the slurry pool 2 into the slurry spray pipe 11 and spray it into the absorption tower body 1 to contact with the flue gas. The slurry after the reaction with the flue gas falls into the slurry pool 2 below, and the slurry circulates between the slurry pool 2 and the slurry spray pipes 11 repeatedly.

[0031] The slurry pool 2 is provided with an agitator 21, which is installed at the bottom of the slurry pool 2. The slurry pool 2 is provided with a slurry pump 12 on one side ( Figure 1 At least two agitators 21 are installed (on the left side in the middle). In this embodiment, there are two agitators 21, and the two agitators 21 are staggered with the slurry pump 12.

[0032] A demister 3 is installed on the top of the absorption tower. In this embodiment, the demister 3 is Figure 3 The baffle demister 3 shown in the figure has flushing pipes 31 installed above and below the demister 3. The flushing pipes 31 include a circular flushing pipe rack 34 and a plurality of flushing nozzles installed on the flushing pipe rack 34. The flushing nozzles are aligned with the channel 33 of the demister, as shown in FIG. Figure 4 As shown, the middle portion of the flushing pipe support 34 of the flushing pipe 31 below the demister protrudes upward.

[0033] A defoaming net 22 is installed above the slurry pool 2. Figure 2 As shown, a plurality of defoaming rods 221 are vertically welded to the bottom of the defoaming net 22. The defoaming net 22 is made of corrosion-resistant hard metal or plastic. The interior of the defoaming net 22 is hollow. A plurality of defoaming nozzles 222 are connected to the defoaming net 22. The defoaming net 22 is connected to a water supply pipe 32. The water supply pipe 32 is also connected to the flushing pipe 31. The water supply pipe 32 is used to access process water in the production system.

[0034] In actual use, the flue gas enters the absorption tower body 1 from the flue gas inlet 13, and flows to the outlet at the top of the absorption tower body 1. The slurry pump 12 pumps the slurry in the slurry pool 2 into the slurry spray pipe 11. The slurry spray pipe 11 sprays the slurry on the flue gas, and the flue gas contacts and reacts with the slurry to complete the desulfurization. The desulfurized flue gas is defogged by the demister 3 and then discharged from the outlet at the top of the absorption tower body 1. The flushing nozzle is regularly started to spray process water on the demister 3 to flush it, which can effectively extend the service life of the demister 3.

[0035] During operation, the stirrer 21 stirs the slurry in real time, and the bubbles generated in the slurry float on the surface of the slurry. When the bubbles come into contact with the vertical defoaming rod 221, the defoaming rod 221 can puncture the bubbles to complete defoaming; when the bubbles that are not in contact with the defoaming rod 221 come into contact with the defoaming net 22, they can also hit the defoaming net 22 to complete defoaming when they are affected by the floating slurry. On this basis, the process water flows into the defoaming net 22 and is sprayed onto the slurry surface through the defoaming nozzle 222 on the defoaming net 22 to further defoam and ensure the defoaming effect.

[0036] Embodiment 2:

[0037] The difference between this embodiment and embodiment 1 is that the defoaming net 22 is provided with two layers, the meshes of the two layers of defoaming nets 22 are staggered, and the defoaming rods 221 on the two layers of defoaming nets 22 are also staggered. The use of two layers of defoaming nets 22 can better defoam and further improve the defoaming effect.

[0038] The above is only an embodiment of the utility model, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. An absorption tower for flue gas desulfurization, comprising an absorption tower body, a slurry spray pipe is arranged in the absorption tower body, a slurry pool is below the slurry spray pipe, a slurry pump is connected between the slurry pool and the slurry spray pipe, and a demister is arranged on the top of the absorption tower, characterized in that: At least two layers of defoaming nets are arranged above the slurry pool, a number of defoaming rods are vertically arranged at the bottom of the defoaming nets, and flushing pipes are arranged above and below the demister.

2. The flue gas desulfurization absorption tower according to claim 1, characterized in that: The defoaming net is hollow inside, is connected with a water supply pipe, and is connected with a plurality of defoaming nozzles.

3. The flue gas desulfurization absorption tower according to claim 2, characterized in that: The defoaming net is provided with two layers, and the mesh holes of the two layers of defoaming net are staggered.

4. The flue gas desulfurization absorption tower according to claim 3, characterized in that: The defoaming rods on the two layers of defoaming nets are also staggered.

5. The flue gas desulfurization absorption tower according to claim 4, characterized in that: The flushing pipe and the defoaming net share the same water supply pipe.

6. The flue gas desulfurization absorption tower according to claim 5, characterized in that: A stirrer is installed in the slurry pool and is arranged at the bottom of the slurry pool.

7. The flue gas desulfurization absorption tower according to claim 6, characterized in that: The agitators are arranged on both sides of the slurry pool, and at least two agitators are arranged on one side of the slurry pool where the slurry pump is arranged, and the agitators and the slurry pump are arranged staggered.

8. The flue gas desulfurization absorption tower according to claim 7, characterized in that: The flushing pipe comprises a circular flushing pipe rack and a plurality of flushing nozzles installed on the flushing pipe rack. The flushing nozzles are aligned with the passage of the demister. The middle part of the flushing pipe rack of the flushing pipe below the demister protrudes upward.

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