Tail gas treatment system in lime slaker

Abstract

The utility model discloses a tail gas treatment system in a lime slaker, which comprises an induced draft fan, a dust remover and a water tank, two venturi tubes are arranged in parallel between the induced draft fan and the dust remover, a cyclone condenser is arranged on the dust remover, a discharge pipe on the cyclone condenser extends into the water tank, and the water tank is communicated with the venturi tubes. An air inlet valve and an air inlet pressure gauge are arranged between the venturi tube and the induced draft fan, an air outlet valve and an air outlet pressure gauge are arranged between the venturi tube and the dust remover, a high-pressure air source is communicated between the air outlet valve and the air outlet pressure gauge, a dust storage device is communicated between the air inlet valve and the air inlet pressure gauge, and a dust stopping valve is arranged in front of a feeding port of the dust storage device. A high-pressure air source is communicated between the air outlet valve and the air outlet pressure gauge, and an air stop valve is arranged in front of an air outlet of the high-pressure air source. The venturi tube dredging device is simple in structure and high in dust removal efficiency, and dredging can be achieved without shutdown or disassembly when the venturi tube is blocked.

Description

Technical Field

[0001] The utility model relates to the field of quicklime digestion equipment, in particular to a tail gas treatment system in a lime digester. Background Art

[0002] Lime digester is a special equipment for digesting quicklime into lime milk. Quicklime undergoes a violent chemical reaction when it meets water during the digestion process, and a large amount of water vapor and lime dust will be produced during the reaction. This requires the treatment of the tail gas produced by the lime digester. At present, the market generally uses an induced draft fan to send high-temperature steam into the heat exchanger for heat exchange and cooling, and then sends the condensed water to the dust collector for filtration. The dust mixed in the condensed water is easy to adhere to the inner wall of the heat exchanger after cooling, causing the heat exchanger to be blocked.

[0003] In response to the above defects, a quicklime digestion system with a dust removal device with announcement number: CN209906652U and a quicklime digestion dust-containing water vapor purification device with announcement number: CN212492144U are disclosed on the market. Both patents require the use of sponges for adsorption and then spraying dust removal with spray pipes, which not only has a complex structure but also causes waste of water resources. Utility Model Content

[0004] The utility model aims to provide an exhaust gas treatment system in a lime digester which has a simple structure, high dust removal efficiency and can clear the Venturi pipe without stopping the machine when the Venturi pipe is blocked.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: an exhaust gas treatment system in a lime digester, comprising: an induced draft fan, a dust collector and a water tank, two venturi tubes are arranged in parallel between the air outlet of the induced draft fan and the air inlet of the dust collector, a cyclone condenser is arranged on the air outlet of the dust collector, the discharge pipe on the cyclone condenser extends into the water tank, an air inlet valve and an air inlet pressure gauge are arranged between the air inlet of the venturi tube and the induced draft fan, an air outlet valve and an air outlet pressure gauge are arranged between the air outlet of the venturi tube and the dust collector, a high-pressure gas source is connected between the air outlet valve and the air outlet pressure gauge, a dust storage device is connected between the air inlet valve and the air inlet pressure gauge, a dust cut-off valve is arranged in front of the feed port of the dust storage device, a high-pressure gas source is connected between the air outlet valve and the air outlet pressure gauge, and an air cut-off valve is arranged in front of the air outlet of the high-pressure gas source.

[0006] Furthermore, in the exhaust gas treatment system in the aforementioned lime scavenger, the connection structure between the induced draft fan and the two venturi tubes is as follows: a first three-way pipe is connected to the air outlet of the induced draft fan, two first folded pipes are flange-connected to the first three-way pipe, a second three-way pipe is connected to each first folded pipe, each second three-way pipe is respectively connected to the air inlet of a venturi tube, an air inlet valve is arranged between the first folded pipe and the second three-way pipe located on the same side, an air inlet pressure gauge is arranged between the second three-way pipe and the venturi tube located on the same side, and a dust collector is connected to the second three-way pipe.

[0007] Furthermore, in the exhaust gas treatment system of the aforementioned lime scavenger, a third three-way pipe is arranged on the feed port of the dust storage device, and both ends of the third three-way pipe are respectively connected to two second three-way pipes, and dust intercepting valves are arranged between the third three-way pipe and the two second three-way pipes.

[0008] Furthermore, in the exhaust gas treatment system of the aforementioned lime digester, the connection structure between the dust collector and the two venturi tubes is as follows: a fourth three-way pipe is connected to the air inlet of the dust collector, two second folded pipes are flange-connected to the fourth three-way pipe, a fifth three-way pipe is connected to each of the second folded pipes, each fifth three-way pipe is connected to the air outlet of a venturi tube, an air outlet valve is arranged between the second folded pipe and the fifth three-way pipe located on the same side, an air outlet pressure gauge is arranged between the fifth three-way pipe and the venturi tube located on the same side, and a high-pressure gas source is connected to the fifth three-way pipe.

[0009] Furthermore, in the exhaust gas treatment system of the aforementioned lime digester, a sixth three-way pipe is arranged on the gas outlet of the high-pressure gas source, and both ends of the sixth three-way pipe are respectively connected to the two fifth three-way pipes, and air shut-off valves are arranged between the sixth three-way pipe and the two fifth three-way pipes.

[0010] Furthermore, in the exhaust gas treatment system in the aforementioned lime digester, the air inlet pressure gauge and the air outlet pressure gauge are both electromagnetic pressure gauges, the air inlet valve, air outlet valve, dust interception valve and air cut-off valve are all electromagnetic valves, and the air inlet pressure gauge, air outlet pressure gauge, air inlet valve, air outlet valve, dust interception valve and air cut-off valve are all electrically connected to the central control device.

[0011] Furthermore, in the exhaust gas treatment system in the aforementioned lime digester, an overflow port and a drainage solenoid valve are provided on the water tank, and the overflow port is located below the discharge pipe.

[0012] Furthermore, in the exhaust gas treatment system in the aforementioned lime digester, a U-shaped exhaust pipe is provided on the top wall of the water tank, the gas outlet end of the U-shaped exhaust pipe faces downward, and a filter membrane is provided on the U-shaped exhaust pipe.

[0013] The advantages of the utility model are: simple structure, the high-temperature steam delivered by the induced draft fan can be accelerated through the venturi tube, so that the high-temperature steam can enter the dust collector at a high speed to remove large particles of dust, and the remaining fine dust enters the cyclone condenser at a high speed with the high-temperature steam to undergo high-speed swirl and condensation, the fine dust and the condensed water enter the water tank through the discharge pipe under their own weight for storage, the fine dust will settle in the water tank by its own weight, and the separated gas has a higher temperature and enters the water tank after passing through the discharge pipe. The impurities in the venturi tube will directly float upward and then be discharged outward; when the throat of the venturi tube in any passage is blocked, the passage is closed and switched to another passage for steam transmission. When the dust cut-off valve and the air cut-off valve are opened between the closed passages, a passage is formed between the high-pressure gas source, the blocked venturi tube and the dust collector. Then the high-pressure gas source is opened to allow the high-pressure gas to recoil and dredge the venturi tube, and the impurities blocked in the throat of the venturi tube are recoiled into the dust collector. In this way, the blocked venturi tube can be dredged without disassembly during the gas transmission process, thereby improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the tail gas treatment system in the lime slaker described in the utility model. DETAILED DESCRIPTION

[0015] The technical solution of the utility model is further described below in conjunction with the accompanying drawings and preferred embodiments.

[0016] like Figure 1As shown, the exhaust gas treatment system in the lime digester described in the utility model includes: an induced draft fan 1, a dust collector 2 and a water tank 3, a first three-way pipe 11 is connected to the air outlet of the induced draft fan 1, two first folded pipes 12 are flange-connected to the first three-way pipe 11, a second three-way pipe 13 is connected to each first folded pipe 12, an air inlet valve 14 is arranged between the first folded pipe 12 and the second three-way pipe 13 located on the same side, a venturi tube 4 is arranged on each second three-way pipe 13, an air inlet pressure gauge 15 is arranged between the second three-way pipe 13 and the air inlet of the venturi tube 4 on the same side, a fifth three-way pipe 21 is connected to the air outlet of each venturi tube 4, and an air outlet pressure gauge 15 is arranged between the venturi tube 4 on the same side and the fifth three-way pipe 21. 22. A second folded tube 23 is connected to each fifth three-way pipe 21. An air outlet valve 24 is arranged between the fifth three-way pipe 21 and the second folded tube 23 on the same side. The two second folded tubes 23 are flange-connected to the same fourth three-way pipe 25. The fourth three-way pipe 25 is connected to the air inlet of the dust collector 2. A cyclone condenser 7 is arranged on the air outlet of the dust collector 2. The discharge pipe 71 on the cyclone condenser 7 extends into the water tank 3. An overflow port 31 and a drain solenoid valve 32 are arranged on the water tank 3. The overflow port 31 is located below the discharge pipe 71. A U-shaped exhaust pipe 33 is arranged on the top wall of the water tank 3. The air outlet end of the U-shaped exhaust pipe 33 faces downward to prevent external dust from falling from the U-shaped exhaust pipe 33 into the water tank 3. A filter membrane is arranged on the U-shaped exhaust pipe 33.

[0017] A third three-way pipe 51 is connected between the two second three-way pipes 13, a dust cut-off valve 52 is provided between the third three-way pipe 51 and the two second three-way pipes 13, the third three-way pipe 51 is connected to the feed port of the dust storage container 5, a sixth three-way pipe 61 is connected between the two fifth three-way pipes 21, an air cut-off valve 62 is provided between the fifth three-way pipe 21 and the two sixth three-way pipes 61, and the sixth three-way pipe 61 is connected to the air outlet of the high-pressure gas source 6.

[0018] The working process is as follows: open the air inlet valve 14 and the air outlet valve 24 on any side to form a passage on that side. At this time, the induced draft fan 1 introduces the high-temperature steam in the lime slaker into the first three-way pipe 11, and then enters the venturi tube 4 through the first folded pipe 12 and the second three-way pipe 13 on that side. The venturi tube 4 accelerates the high-temperature steam. The accelerated high-temperature steam passes through the fifth three-way pipe 21, the second folded pipe 23 and the fourth three-way pipe 25 and then enters the dust collector 2. The dust collector 2 filters out large particles of dust in the high-temperature steam. The high-temperature steam after dust removal maintains a high speed and enters the cyclone condenser 7 for centrifugal condensation. Under the centrifugal action, the high-temperature steam undergoes water vapor separation, and the fine dust mixed in the high-temperature steam passes through the discharge pipe under the action of gravity along with the condensed water. 71 enters the water tank 3 together for storage, the fine dust will settle in the water tank 3, and the separated high-temperature gas enters the water tank 3 along the discharge pipe 71, and then is directly discharged from the U-shaped exhaust pipe 33. The filter membrane in the U-shaped exhaust pipe 33 filters the high-temperature gas to prevent the high-temperature gas from carrying fine dust to the outside. Since the overflow port 31 in the water tank 3 is located below the discharge pipe 71, the highest liquid level in the water tank 3 is lower than the discharge pipe 71, and the water in the water tank 3 will not contact the gas discharged from the discharge pipe 71. After opening the drain solenoid valve 32, the water in the water tank 3 can be discharged from the drain solenoid valve 32. If the water tank 3 is connected to the lime digester, the water in the water tank 3 can flow back to the lime digester for digestion.

[0019] When the pressure of the air inlet pressure gauge 15 on the above-mentioned side increases, while the pressure of the air outlet pressure gauge 22 decreases, it means that the throat in the Venturi tube 4 is blocked by a large amount of dust. At this time, it is necessary to switch the passage, open the air outlet valve 24 and the air inlet valve 14 on the other side in turn, so that a passage is formed on the other side, and then quickly close the air inlet valve 14 and the air outlet valve 24 on this side in turn, and the high-temperature steam induced by the induced draft fan 1 is transported to the dust collector 2 from the passage on the other side, and a closed circuit is formed on this side, and then the dust cut-off valve 52 and the air cut-off valve 62 connected to the second three-way pipe 13 and the fifth three-way pipe 21 of the closed circuit on this side are opened, so that the high-pressure gas source 6 forms a passage through the fifth three-way pipe 21, the Venturi tube 4, the second three-way pipe 13 and the dust storage device 5 on this side, and then the high-pressure gas source 6 is opened, and the high-pressure gas passes through the sixth three-way pipe 61 , the fifth three-way pipe 21 enters the Venturi tube 4 from the air outlet of the Venturi tube 4 to recoil the Venturi tube 4, so that the dust blocked in the throat of the Venturi tube 4 is blown away, and the blown dust passes through the second three-way pipe 13 and the third three-way pipe 51 and enters the dust collector 5. In the recoil and dredging process, the pressure monitored by the air outlet pressure gauge 22 is relatively large at the beginning. After a period of recoil, the pressure value monitored by the air outlet pressure gauge 22 will gradually decrease, and the pressure value monitored by the air inlet pressure gauge 15 will gradually increase. When the pressure values ​​monitored by the air outlet pressure gauge 22 and the air inlet pressure gauge 15 are respectively stabilized for a certain period of time, it means that the dust blocked in the Venturi tube 4 is recoiled into the dust collector 5, and the high-pressure air source 6, the air cut-off valve 62 and the dust cut-off valve 52 are closed in turn.

[0020] In order to improve the automation degree of the system, in this embodiment, the air inlet pressure gauge 15 and the air outlet pressure gauge 22 are electromagnetic pressure gauges, and the air inlet valve 14, the air outlet valve 24, the dust interception valve 52 and the air interception valve 62 are electromagnetic valves. Then the air inlet pressure gauge 15, the air outlet pressure gauge 22, the air inlet valve 14, the air outlet valve 24, the dust interception valve 52, and the air interception valve 62 are electrically connected to the central control device. Among them, it is necessary to set the safety pressure threshold value X of the air inlet pressure gauge 15 and the pressure threshold value Y of the air outlet pressure gauge 22. The safety pressure threshold value X of the air inlet pressure gauge 15 is set to prevent the pressure in the pipe from being too high. The large pressure causes leakage at the connection. The pressure threshold Y of the air outlet pressure gauge 22 is the same as the pressure of the high-pressure gas in the high-pressure gas source 6. When the pressure value of the air inlet pressure gauge 15 of a certain passage is higher than X, it means that the Venturi tube 4 in the passage is blocked and the passage needs to be switched. The central control device controls the air inlet valve 14 and the air outlet valve 24 on both sides to switch, and then controls the opening of the corresponding dust cutoff valve 52 and the air cutoff valve 62 to recoil and dredge the blocked Venturi tube 4. During the dredging process, when the pressure value of the air outlet pressure gauge 22 drops to Y, it means that the Venturi tube 4 is dredged.

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model is described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the utility model can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the utility model should be included in the scope of protection of the claims of the utility model.

Claims

1. The tail gas treatment system in the lime digester is characterized by: include: An induced draft fan, a dust collector and a water tank, two venturi tubes are arranged in parallel between the air outlet of the induced draft fan and the air inlet of the dust collector, a cyclone condenser is arranged on the air outlet of the dust collector, the discharge pipe on the cyclone condenser extends into the water tank, an air inlet valve and an air inlet pressure gauge are arranged between the air inlet of the venturi tube and the induced draft fan, an air outlet valve and an air outlet pressure gauge are arranged between the air outlet of the venturi tube and the dust collector, a high-pressure gas source is connected between the air outlet valve and the air outlet pressure gauge, a dust storage device is connected between the air inlet valve and the air inlet pressure gauge, a dust cut-off valve is arranged in front of the feed inlet of the dust storage device, a high-pressure gas source is connected between the air outlet valve and the air outlet pressure gauge, and an air cut-off valve is arranged in front of the air outlet of the high-pressure gas source.

2. The tail gas treatment system in the lime slaker according to claim 1, characterized in that: The connection structure between the induced draft fan and the two venturi tubes is as follows: a first three-way pipe is connected to the air outlet of the induced draft fan, two first folded pipes are flange-connected to the first three-way pipe, a second three-way pipe is connected to each of the first folded pipes, each second three-way pipe is respectively connected to the air inlet of a venturi tube, an air inlet valve is arranged between the first folded pipe and the second three-way pipe on the same side, an air inlet pressure gauge is arranged between the second three-way pipe and the venturi tube on the same side, and a dust collector is connected to the second three-way pipe.

3. The tail gas treatment system in the lime slaker according to claim 2, characterized in that: A third three-way pipe is arranged on the feed port of the dust storage device, and both ends of the third three-way pipe are respectively connected to the two second three-way pipes, and dust interception valves are arranged between the third three-way pipe and the two second three-way pipes.

4. The tail gas treatment system in the lime slaker according to claim 1, 2 or 3, characterized in that: The connection structure between the dust collector and the two Venturi tubes is as follows: a fourth three-way pipe is connected to the air inlet of the dust collector, two second folded pipes are flange-connected to the fourth three-way pipe, each of the second folded pipes is connected to a fifth three-way pipe, each of the fifth three-way pipes is connected to the air outlet of a Venturi tube, an air outlet valve is arranged between the second folded pipe and the fifth three-way pipe located on the same side, an air outlet pressure gauge is arranged between the fifth three-way pipe and the Venturi tube located on the same side, and a high-pressure gas source is connected to the fifth three-way pipe.

5. The tail gas treatment system in the lime slaker according to claim 4, characterized in that: A sixth three-way pipe is arranged on the gas outlet of the high-pressure gas source, and both ends of the sixth three-way pipe are respectively connected to the two fifth three-way pipes, and air cut-off valves are arranged between the sixth three-way pipe and the two fifth three-way pipes.

6. The tail gas treatment system in the lime slaker according to claim 5, characterized in that: The air inlet pressure gauge and the air outlet pressure gauge are both electromagnetic pressure gauges, the air inlet valve, air outlet valve, dust cutoff valve and air cutoff valve are all electromagnetic valves, and the air inlet pressure gauge, air outlet pressure gauge, air inlet valve, air outlet valve, dust cutoff valve and air cutoff valve are all electrically connected to the central control device.

7. The tail gas treatment system in the lime slaker according to claim 6, characterized in that: An overflow port and a drainage solenoid valve are arranged on the water tank, and the overflow port is located below the discharge pipe.

8. The tail gas treatment system in the lime slaker according to claim 7, characterized in that: A U-shaped exhaust pipe is arranged on the top wall of the water tank, the air outlet end of the U-shaped exhaust pipe faces downward, and a filter membrane is arranged on the U-shaped exhaust pipe.

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