Ultra-low-concentration emission RTO switching valve gas sealing device

Abstract

The utility model discloses an ultralow-concentration emission RTO switching valve air-tight sealing device which comprises an in-valve exhaust pipe arranged in a switching valve, the in-valve exhaust pipe is connected with an air-tight sealing pipeline located outside the switching valve, and a graphite packing fixing bottom ring and an annular air groove are fixed to the upper surface and the lower surface of a plate face at the joint of the top of a wall plate and a valve plate respectively. An annular graphite packing is concentrically arranged on the graphite packing fixing bottom ring, the upper surface of the graphite packing is higher than the upper surface of the graphite packing fixing bottom ring, the in-valve exhaust pipe is communicated with the annular air groove, the valve plate is connected with a pneumatic structure, and the pneumatic structure drives the valve plate to move up and down to open or close the switching valve. According to the utility model, the emission of VOCs can be effectively reduced, and the environmental pollution is reduced; more production waste gas can be treated under the condition that the requirement of the emission amount is met due to the lower emission rate, and the device can be suitable for small-specification equipment to reduce the investment cost of environment-friendly equipment and reduce the energy consumption.

Description

Technical Field

[0001] The utility model belongs to the technical field of environmental protection equipment and relates to a gas sealing device for an RTO switching valve with ultra-low concentration emissions. Background Technique

[0002] With the strengthening of domestic environmental protection policies and the drive of the dual-carbon goal, in recent years, many newly built factories have the task of controlling the total carbon emission index. In the flexible packaging printing industry, many customers require that the emission index of waste gas purification equipment be higher and higher. In view of this, the development of low-emission waste gas purification equipment has become a new market demand in the future. At present, the non-methane total hydrocarbon (NMHC) emissions of RTO (Regenerative Thermal Oxidizer) regenerative combustion devices on the market are generally around 30 mg / m 3 , which can no longer meet the emission values required by customers in some regions. The purpose of this device is to optimize and improve the design of the emissions of existing RTOs from a mechanical aspect in order to meet the current market demand.

[0003] The leakage rate and treatment efficiency of the RTO directly affect the RTO emissions. Therefore, reducing the leakage of the RTO is crucial. The leakage of the RTO mainly occurs at the valve plate sealing joint surface of the switching valve of the RTO. At present, the main valve plate sealing methods of RTO products on the market include metal hard sealing, single graphite packing soft sealing, double hard sealing + compressed air gas sealing, etc. Their sealing does not meet the requirement of zero leakage, and there will still be a small amount of VOCs gas leaking into the exhaust pipe during equipment operation or valve plate switching, thus increasing the emissions. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a gas sealing device for an RTO switching valve with ultra-low concentration emissions, which solves the problem of leakage existing in the valve plate joint surface of the existing RTO switching valve.

[0005] The technical solution adopted by the utility model is that for a gas sealing device for an RTO switching valve with ultra-low concentration emissions, the RTO regenerative thermal oxidizer includes a blower, a combustion chamber, a switching valve, an intake pipe, an exhaust pipe, and a chimney. The switching valves correspond to the combustion chambers one by one, and the switching valve is located below the corresponding combustion chamber. The switching valve is provided with two chambers, which are respectively located on the intake side and the exhaust side. Each chamber is surrounded by a wall plate and a valve plate. The gas sealing device includes an internal valve suction pipe arranged inside the switching valve. The internal valve suction pipe is connected to a gas sealing pipeline located outside the switching valve. Graphite packing fixed bottom rings and annular gas grooves are respectively fixed on the upper and lower surfaces of the plate surface at the joint of the top of the wall plate and the valve plate. An annular graphite packing is concentrically arranged on the graphite packing fixed bottom ring. The upper surface of the graphite packing is higher than the upper surface of the graphite packing fixed bottom ring. The internal valve suction pipe is communicated with the annular gas groove. The valve plate is connected with a pneumatic structure, and the pneumatic structure drives the valve plate to move up and down to open or close the switching valve.

[0006] The features of the present utility model also lie in that:

[0007] The pneumatic structure includes a connecting shaft, and a pneumatic actuator is connected to the connecting shaft.

[0008] Two graphite packing installation grooves are provided in the upper part of the graphite packing fixed bottom ring. The bottom of the graphite packing fixed bottom ring is welded and fixed to the wall plate. Graphite packing is arranged in each graphite packing installation groove. A plurality of through holes are provided between the two graphite packing installation grooves, and the through holes penetrate through the thicknesses of the graphite packing fixed bottom ring and the wall plate and are communicated with the annular air groove.

[0009] The top of the annular air groove is welded and fixed to the wall plate. An air extraction hole is provided at the bottom of the annular air groove, and an inner-valve air extraction pipe is welded at the air extraction hole. The annular air groove is communicated with the inner-valve air extraction pipe through the air extraction hole.

[0010] The airtight pipeline includes an airtight pipeline air extraction fan. The air inlet and the air outlet of the airtight pipeline air extraction fan are respectively connected with a sealed fan outlet pipe and a sealed fan inlet pipe. One end of the sealed fan outlet pipe is connected with the air inlet of the airtight pipeline air extraction fan, and the other end is connected with the air inlet of the RTO centrifugal fan. The air outlet of the RTO centrifugal fan is connected with the intake pipeline. A manual butterfly valve is arranged on the sealed fan outlet pipe. The sealed fan inlet pipe is connected with an air extraction branch pipe, and the air extraction branch pipe is connected with the inner-valve air extraction pipe.

[0011] The air extraction branch pipe includes an intake-side air extraction branch pipe and an exhaust-side air extraction branch pipe. The intake-side air extraction branch pipe is connected with the inner-valve air extraction pipe of the intake side chamber of the combustion chamber, and the exhaust-side air extraction branch pipe is connected with the inner-valve air extraction pipe of the exhaust side chamber of the combustion chamber.

[0012] An air extraction branch pipe manual ball valve, an air extraction branch pipe electric valve, and a positive and negative pressure pressure gauge are arranged on the air extraction branch pipe.

[0013] The beneficial effects of the present utility model are:

[0014] The airtight device of the RTO switching valve with ultra-low concentration emission of the present utility model can effectively reduce the emission of VOCs and reduce environmental pollution; a lower emission rate can process more production waste gas while meeting the emission requirements, and it can also be applicable to small-scale equipment to reduce the investment cost of environmental protection equipment and reduce energy consumption. Description of the Drawings

[0015] Figure 1 is a structural schematic diagram of the airtight device of the RTO switching valve with ultra-low concentration emission of the present utility model;

[0016] Figure 2 is a schematic diagram of the internal sealing structure of the switching valve of the airtight device of the RTO switching valve with ultra-low concentration emission of the present utility model;

[0017] Figure 3It is a partial view of the gas seal of the switching valve plate of the ultra-low concentration emission RTO switching valve gas seal device of the present utility model.

[0018] In the figure, 1. switching valve, 2. RTO centrifugal fan, 3. sealed air outlet pipe of the fan, 4. manual butterfly valve, 5. air extraction fan for the sealed air path, 6. air extraction branch pipe on the intake side of switching valve A, 7. air extraction branch pipe on the exhaust side of switching valve A, 8. sealed air inlet pipe of the fan, 9. air extraction branch pipe on the intake side of switching valve B, 10. air extraction branch pipe on the exhaust side of switching valve B, 11. air extraction branch pipe on the intake side of switching valve C, 12. air extraction branch pipe on the exhaust side of switching valve C, 13. manual ball valve for the air extraction branch pipe, 15. electric valve for the air extraction branch pipe, 16. positive and negative pressure gauge, 17. internal air extraction pipe of the lift valve, 18. connecting shaft, 19. valve plate, 20. graphite packing, 21. fixed bottom ring for the graphite packing, 22. annular air groove, 23. wall plate. Specific implementation mode

[0019] The present utility model will be described in detail below in conjunction with the accompanying drawings and specific implementation modes.

[0020] Embodiment 1

[0021] This embodiment provides an ultra-low concentration emission RTO switching valve gas seal device. The RTO regenerative thermal oxidizer (Regenerative Thermal Oxidizer, abbreviated as RTO) is an energy-saving environmental protection device for treating medium and low concentration volatile organic waste gases (VOCs). The RTO regenerative thermal oxidizer includes a blower, three combustion chambers (combustion chamber A, combustion chamber B, combustion chamber C), three switching valves 1 (switching valve A, switching valve B, switching valve C), an intake pipe, an exhaust pipe, and a chimney. The switching valves 1 correspond to the combustion chambers one by one. The switching valves 1 (lift valves) are located below the corresponding combustion chambers. Each switching valve 1 is provided with two chambers, which are located on the intake side and the exhaust side respectively. Each chamber is surrounded by a wall plate 23 and a valve plate 19. The VOCs waste gas is sent into the switching valve 1 through the intake pipe, and the waste gas is sent into different chambers of the combustion chamber for treatment by switching the intake side switching valve. The treated waste gas is sent into the chimney and discharged into the atmosphere through the exhaust side switching valve. Specifically, as Figure 1 shown, if the VOCs gas on the intake side leaks into the exhaust valve space through the switching valve, the VOCs gas will be discharged into the atmosphere along with the treated waste gas, causing pollution and thus reducing the actual treatment efficiency of the RTO.

[0022] The gas seal device includes an internal air extraction pipe 17 arranged inside the switching valve 1. The internal air extraction pipe 17 is connected with a gas seal pipeline located outside the switching valve, as Figure 2As shown in the figure, a graphite packing fixing bottom ring 21 and an annular air groove 22 are respectively fixed on the upper and lower surfaces of the plate surface at the joint of the top of the wall panel 23 and the valve plate 19. An annular graphite packing 20 is concentrically arranged on the graphite packing fixing bottom ring 21. The upper surface of the graphite packing 20 is higher than the upper surface of the graphite packing fixing bottom ring 21. The inner valve air extraction pipe 17 is communicated with the annular air groove 22. The valve plate 19 is connected with a pneumatic structure. The pneumatic structure includes a connecting shaft 18. The connecting shaft is connected with a pneumatic actuator. The pneumatic structure drives the valve plate 19 to move up and down to open or close the switching valve 1. Closing the switching valve 1 means that the valve plate 19 presses onto the graphite packing 20.

[0023] Embodiment 2

[0024] This embodiment provides an airtight device for an RTO switching valve with ultra-low concentration emissions. On the basis of Embodiment 1, as Figure 3 shown, two graphite packing installation grooves are provided in the upper part of the graphite packing fixing bottom ring 21. The bottom of the graphite packing fixing bottom ring 21 is welded and fixed to the wall panel 23. Each graphite packing installation groove is provided with a graphite packing 20. 20 - 30 through holes with a diameter of about Φ20 are provided between the two graphite packing installation grooves. The through holes penetrate through the thickness of the graphite packing fixing bottom ring 21 and the wall panel 23 and are communicated with the annular air groove 22.

[0025] The top of the annular air groove 22 is welded and fixed to the wall panel 23. 4 air extraction holes with a diameter of Φ30 - Φ40 are provided at the bottom of the annular air groove 22. The inner valve air extraction pipe 17 is welded at the air extraction holes. The annular air groove 22 is communicated with the inner valve air extraction pipe 17 through the air extraction holes.

[0026] Embodiment 3

[0027] This embodiment provides an airtight device for an RTO switching valve with ultra-low concentration emissions. On the basis of Embodiments 1 - 2, the airtight pipeline includes an airtight air extraction fan 5 for the airtight air path. The air inlet and air outlet of the airtight air extraction fan 5 are respectively connected with a sealed fan outlet pipe 3 and a sealed fan inlet pipe 8. One end of the sealed fan outlet pipe 3 is connected with the air inlet of the airtight air extraction fan 5, and the other end is connected with the air inlet of the RTO centrifugal fan 2. The air outlet of the RTO centrifugal fan 2 is connected with the intake pipeline. A manual butterfly valve 4 is provided on the sealed fan outlet pipe 3. The manual butterfly valve 4 can adjust the air extraction air volume and air pressure in the main pipe. The sealed fan inlet pipe 8 is connected with an air extraction branch pipe, and the air extraction branch pipe is connected with the inner valve air extraction pipe 17.

[0028] The extraction branch pipe includes an intake-side extraction branch pipe and an exhaust-side extraction branch pipe. The extraction branch pipe of switching valve A includes a switching valve A intake-side extraction branch pipe 6 and a switching valve A exhaust-side extraction branch pipe 7. The extraction branch pipe of switching valve B includes a switching valve B intake-side extraction branch pipe 9 and a switching valve B exhaust-side extraction branch pipe 10. The extraction branch pipe of switching valve C includes a switching valve C intake-side extraction branch pipe 11 and a switching valve C exhaust-side extraction branch pipe 12. The intake-side extraction branch pipe is connected to the in-valve extraction air pipe 17 of the intake-side chamber of the combustion chamber, and the exhaust-side extraction branch pipe is connected to the in-valve extraction air pipe 17 of the exhaust-side chamber of the combustion chamber.

[0029] A manual ball valve 13, an electric valve 15 for the extraction branch pipe, and a positive and negative pressure gauge 16 are provided on each extraction branch pipe. The manual ball valve 13 is used to adjust the extraction pressure and extraction air volume of each branch. The opening and closing of the electric valve 15 for the extraction branch pipe can control whether the lifting valve inside it performs extraction. The positive and negative pressure gauge 16 can view the negative pressure value inside the pipe during extraction, and the extraction situation can be judged according to the magnitude of the value.

[0030] The extraction fan 5 for the seal air path is turned on when the equipment is started and turned off when the equipment is shut down. The electric valve 15 for the extraction branch pipe is linked with the pneumatic actuator of the corresponding lifting valve. When the lifting valve is closed, the electric valve 15 for the extraction branch pipe is opened, and when the lifting valve is opened, the electric valve 15 for the extraction branch pipe is closed.

[0031] The working process of the airtight device for the RTO switching valve with ultra-low concentration emissions of the present utility model is specifically as follows:

[0032] When the RTO is operating, the VOCs waste gas will pass through one side of the lifting valve 1, and the other side is the purified gas after treatment. When there is leakage at the sealing joint surface of the valve plate 19 and the graphite packing 20, the VOCs gas will first pass through the inner (or outer) graphite packing 20. When the gas enters the space between the two graphite packings, due to the extraction of the extraction fan 5 for the seal air path, the space between the two graphite packings is in a negative pressure state, so the leaked VOCs gas will be drawn into the seal fan and then sent to the inlet position of the RTO centrifugal fan 2. The waste gas will be sent into the RTO by the RTO centrifugal fan 2 again for purification treatment.

Claims

1. An air-sealing device for an ultra-low concentration emission RTO switching valve, the RTO regenerative thermal oxidizer comprising a blower, a combustion chamber, a switching valve (1), an air intake duct, an exhaust duct, and a chimney, the switching valve (1) corresponding to the combustion chamber one by one, the switching valve (1) being located at the lower part of the corresponding combustion chamber, the switching valve (1) being provided with two chambers, the two chambers being located at the air intake side and the exhaust side respectively, each of the chambers being surrounded by a wall plate (23) and a valve plate (19), characterized in that: The air-sealing device comprises an in-valve exhaust pipe (17) arranged inside the switching valve (1), the in-valve exhaust pipe (17) being connected to an air-sealing pipeline located outside the switching valve, a graphite packing fixing bottom ring (21) and an annular air groove (22) being fixed on the plate surface and the lower surface of the plate surface where the top of the wall plate (23) and the valve plate (19) meet, respectively, an annular graphite packing (20) being concentrically arranged on the graphite packing fixing bottom ring (21), the upper surface of the graphite packing (20) being higher than the upper surface of the graphite packing fixing bottom ring (21), the in-valve exhaust pipe (17) being connected to the annular air groove (22), the valve plate (19) being connected to a pneumatic structure, the pneumatic structure driving the valve plate (19) to move up and down to open or close the switching valve.

2. The ultra-low concentration emission RTO switching valve gas sealing device according to claim 1 is characterized in that: The pneumatic structure comprises a connecting shaft (18), and the connecting shaft is connected to a pneumatic actuator.

3. The ultra-low concentration emission RTO switching valve gas sealing device according to claim 1 is characterized in that: Two millstone packing installation grooves are formed on the upper part of the graphite packing fixing bottom ring (21). The bottom of the graphite packing fixing bottom ring (21) is welded and fixed to the wall plate (23). A graphite packing (20) is arranged in each millstone packing installation groove. A plurality of through holes are formed between the two millstone packing installation grooves. The through holes penetrate the graphite packing fixing bottom ring (21) and the thickness of the wall plate (23) and are connected to the annular air groove (22).

4. The ultra-low concentration emission RTO switching valve gas sealing device according to claim 1, characterized in that: The top of the annular air groove (22) is welded and fixed to the wall plate (23); an exhaust hole is provided at the bottom of the annular air groove (22); an exhaust pipe (17) in the valve is welded at the exhaust hole; the annular air groove (22) and the exhaust pipe (17) in the valve are connected through the exhaust hole.

5. The ultra-low concentration emission RTO switching valve gas sealing device according to claim 1, characterized in that: The airtight pipeline comprises a sealed air path exhaust fan (5); the air inlet and the air outlet of the sealed air path exhaust fan (5) are respectively connected to a sealed fan outlet pipe (3) and a sealed fan inlet pipe (8); one end of the sealed fan outlet pipe (3) is connected to the air inlet of the sealed air path exhaust fan (5); the other end is connected to the air inlet of the RTO centrifugal fan (2); the air outlet of the RTO centrifugal fan (2) is connected to the air inlet pipeline; a manual butterfly valve (4) is provided on the sealed fan outlet pipe (3); the sealed fan inlet pipe (8) is connected to an exhaust branch pipe; and the exhaust branch pipe is connected to the exhaust pipe (17) in the valve.

6. The ultra-low concentration emission RTO switching valve gas sealing device according to claim 5, characterized in that: The exhaust branch pipe comprises an intake side exhaust branch pipe and an exhaust side exhaust branch pipe, wherein the intake side exhaust branch pipe is connected to the exhaust pipe (17) in the valve of the intake side chamber of the combustion chamber, and the exhaust side exhaust branch pipe is connected to the exhaust pipe (17) in the valve of the exhaust side chamber of the combustion chamber.

7. The ultra-low concentration emission RTO switching valve gas sealing device according to claim 5, characterized in that: The exhaust branch pipe is provided with an exhaust branch pipe manual ball valve (13), an exhaust branch pipe electric valve (15), and a positive and negative pressure gauge (16).

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