Sulfuric acid flue gas combination valve

Abstract

The utility model discloses a sulfuric acid flue gas combination valve, include: valve body, valve plate, shaft sleeve and valve rod, the shaft sleeve is installed in the mounting hole of valve body both ends, the valve body includes first valve body and second valve body, first valve body and second valve body fold and accommodate valve plate and valve rod in, the cooperation face of first valve body and second valve body is equipped with flange face respectively, the flange face is detachable connection fold through bolt, the flange face is equipped with two sections of clamps outward, and two sections of clamps are symmetrical and surround the circumference of flange face and are connected as a whole through bolt. The utility model has the beneficial effects that the first valve body and second valve body combination type assembly technology are used, and a clamp structure is added in the middle part of the valve body formed by first valve body and second valve body folding, and the telescopic function is increased on the single side of valve body, and the design of this structure makes when maintaining and overhauling, the valve body can be easily removed, and the time of on -the -spot rapid online cleaning overhauling is greatly shortened.

Description

Technical Field

[0001] This utility model relates to the field of sulfuric acid production, and in particular to a combined valve for sulfuric acid flue gas. Background Technology

[0002] The butterfly valve is a simple regulating valve. Its design features include good wear resistance, stable and reliable operation, convenient operation, and sensitive action, making it an ideal choice for handling dusty gases and flue gas pipelines. It is widely used in ventilation and dust removal systems, especially in dusty gases, ventilation and purification devices, and sulfuric acid flue gas pipelines, as a flow regulation and throttling device. This application of butterfly valves is not limited to the shut-off type, used to isolate or cut off airflow in pipelines, but also includes the regulating type, which plays a role in balancing flow regulation in ventilation systems.

[0003] Dust and acid sludge are present in flue gas ducts. When conventional butterfly valves are shut down, the temperature drops, and the acid sludge easily accumulates and hardens at the valve stem and bushing. Simultaneously, the metal profiles have a coefficient of thermal contraction; changes in operating temperature can cause the gaps between the metal parts to narrow, leading to the valve stem and bushing seizing together and the valve failing to open or close. Furthermore, excessive dust in the flue gas ducts can accumulate on the valve body sealing surface, exceeding its height and obstructing valve operation. This necessitates valve disassembly, making quick on-site cleaning and maintenance difficult and severely impacting production.

[0004] For example, Chinese Utility Model Patent Publication No. CN221943208U discloses a corrosion-resistant and wear-resistant butterfly valve, including a valve body, a valve stem, and a valve plate. The valve body includes a base layer, a wear-resistant layer, and a reinforcing layer. Heat transfer holes are formed on both sides of the valve stem, and a heating rod is installed inside the valve stem. A connection hole is formed on one half of the side surface of the valve plate, and a heating chamber is formed inside the valve plate. This patent effectively increases the overall wear resistance and corrosion resistance of the valve body by spraying the wear-resistant layer onto the outer surface of the base layer. The heating rod slowly raises the temperature inside the heating chamber. Its valve body is a one-piece structure, avoiding the problem of acid sludge accumulating and hardening at the valve stem bushing, which can cause the valve stem and bushing to seize up during temperature changes, hindering quick maintenance.

[0005] For example, Chinese utility model patent publication number CN222351589U discloses a butterfly valve with a heating structure, including a butterfly valve body, a heating component mounted on the butterfly valve body, a protective shell, a primary motor mounted on the protective shell, a lead screw connected to the output end of the primary motor, and a bearing rotatably connecting the end of the lead screw away from the primary motor to the butterfly valve body. The lead screw is threadedly connected to a movable mounting seat, which is located inside the protective shell. A heating plate is mounted on the movable mounting seat, extending into the butterfly valve body and into its internal cavity, allowing it to contact the fluid and reduce heat loss during heat transfer. However, this patented butterfly valve is a one-piece structure, making quick maintenance difficult when disassembly is required.

[0006] Chinese utility model patent publication number CN208565581U discloses a butterfly valve for preventing valve stem jamming, including a valve body, valve stem, butterfly plate, bracket, and transmission device. The valve body has a shaft hole at both the top and bottom. The valve stem passes through the shaft hole and is fixedly connected to the butterfly plate by a cylindrical pin. Disc springs are fitted at the upper and lower ends of the valve stem in the gap between the butterfly plate and the valve body. An upper bushing and a lower bushing are respectively installed at the shaft hole positions on both ends of the valve stem. The gap between the upper bushing and the shaft hole is filled with packing material. A pressure plate is fitted on the valve stem above the packing material. The top of the valve stem is fixedly connected to the transmission device. This patent uses disc springs at the upper and lower ends of the valve stem in the gap between the butterfly plate and the valve body to prevent dust and particles from entering between the valve stem and the shaft hole. However, the disc springs are located inside the valve body, which can easily obstruct the operation of the valve plate and cause dust to accumulate on the disc springs, hindering the opening and closing of the valve plate. Utility Model Content

[0007] The technical problem to be solved by this utility model is that the existing butterfly valve body is an integral structure, which makes it impossible to quickly disassemble and repair when the valve stem encounters a problem. At least one of the valve stem and bushing is prone to seizing in the flue gas pipeline. Therefore, a sulfuric acid flue gas combination valve is provided.

[0008] The technical solution of this utility model is: a sulfuric acid flue gas combination valve, comprising: a valve body, a valve plate, a bushing, and a valve stem. The bushing is installed in the mounting holes at both ends of the valve body. The valve body includes a first valve body and a second valve body. The first valve body and the second valve body are closed to accommodate the valve plate and the valve stem. The mating surfaces of the first valve body and the second valve body are respectively provided with flange surfaces. The flange surfaces are detachably connected by bolts. Two clamps are provided on the outside of the flange surfaces. The two clamps symmetrically surround the circumference of the flange surfaces and are connected as one unit by bolts.

[0009] The improvement of the above solution is that the mounting hole has a reserved installation space at one end near the valve plate, and one end of the valve stem is provided with a boss located in the installation space. The end of the boss near the valve plate is connected to a metal bellows that fits the valve stem. The end of the metal bellows is connected to a retaining ring that slides with the valve stem. The retaining ring is made of polymer material.

[0010] The retaining ring described in the above scheme is an arc shape that bends towards the valve plate.

[0011] The boss described in the above scheme includes a base and a thickened part. The base is made of the same material as the valve stem, and the thickened part is made of polymer material.

[0012] The boss described in the above scheme is an arc shape that bends away from the valve plate.

[0013] The boss described in the above scheme is made of polymer material, and the boss is in the shape of an arc that bends away from the valve plate.

[0014] A further improvement to the above scheme is that temperature control mechanisms are installed at both ends of the valve stem located outside the valve body.

[0015] A further improvement to the above solution is that an expansion joint is installed on the outer end face of the first valve body.

[0016] In the above scheme, the sealing surface of the valve plate and the sealing surface of the valve body are complementary spherical tangents.

[0017] The beneficial effects of this utility model are that it adopts a combined assembly process of the first valve body and the second valve body. A clamp structure is added to the middle of the valve body formed by the combination of the first valve body and the second valve body, and the valve body has a telescopic function on one side. This structural design makes it easy to remove the valve body during maintenance and repair, which greatly shortens the time for on-site quick online cleaning and maintenance. Through this design, the valve's opening and closing function can be quickly restored, ensuring the efficient operation of the equipment and the convenience of maintenance. Through the cooperation of the boss, metal bellows and retaining ring, it can prevent smoke and dust from entering the installation space when the valve body is working, protect the bushing, and provide an isolated heat-insulating space, reducing the possibility of the medium condensing into acid sludge and invading the valve stem bushing, causing the bushing and valve stem to seize up. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the sulfuric acid flue gas combination valve of this utility model in the explosion stage;

[0019] Figure 2 yes Figure 1 Schematic diagram of the central boss, metal bellows, and retaining ring;

[0020] Figure 3 This is a schematic diagram of the boss and retaining ring of a preferred embodiment of the present invention;

[0021] Figure 4 This is a cross-sectional view of the sulfuric acid flue gas combination valve of this utility model after removing the boss, metal bellows and retaining ring;

[0022] Figure 5 This is a schematic diagram of the sulfuric acid flue gas combination valve of this utility model;

[0023] In the figure, 1. Valve body, 11. First valve body, 12. Second valve body, 13. Flange face, 14. Clamp, 2. Valve plate, 3. Bushing, 4. Valve stem, 5. Mounting hole, 6. Boss, 61. Base, 62. Thickened part, 7. Metal bellows, 8. Retaining ring, 9. Temperature control mechanism, 10. Expansion joint. Detailed Implementation

[0024] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments implemented by those skilled in the art without creative effort are within the protection scope of this utility model.

[0025] like Figure 1 , Figure 5 As shown, a sulfuric acid flue gas combination valve includes: a valve body 1, a valve plate 2, a bushing 3, and a valve stem 4. The bushing is installed in mounting holes 5 at both ends of the valve body. The valve body includes a first valve body 11 and a second valve body 12, each with two corresponding mounting holes. The first and second valve bodies are closed to accommodate the valve plate and valve stem. The bushing is installed in the mounting holes and has a clearance fit with the valve stem. The mating surfaces of the first and second valve bodies are respectively provided with flange faces 13. The flange faces are detachably connected by bolts. Two clamps 14 are provided on the outside of the flange faces. The two clamps symmetrically surround the circumference of the flange faces and are connected as a whole by bolts. The first and second valve bodies are fixed in one dimension through the corresponding flange faces, and fixed in a second dimension through the cooperation of the two clamps, ensuring the stability of the valve body after closure. When disassembly is required, only the clamps and the bolts corresponding to the flange faces need to be released, and the two clamps need to be separated. An expansion joint 10 is installed on the outer end face of the first valve body. By pushing the expansion joint, the valve body can be easily opened in half. This design greatly simplifies the process of quickly cleaning and inspecting internal parts, thus significantly improving maintenance efficiency. This allows maintenance personnel to complete the inspection and maintenance of the valve body in a shorter time, ensuring the normal operation of the equipment and extending its service life.

[0026] like Figures 1-4 As shown, in a preferred embodiment of this utility model, the mounting hole has a reserved installation space at one end near the valve plate. One end of the valve stem is provided with a boss 6 located within the installation space. A metal bellows 7, which houses the valve stem, is connected to the end of the boss near the valve plate. A retaining ring 8, which slides with the valve stem, is connected to the end of the metal bellows. The retaining ring is made of a polymer material. Specifically, the retaining ring can be polytetrafluoroethylene (PTFE) or polyetheretherketone (PEEK), which has a large coefficient of thermal expansion and expands significantly when heated. It also has good high-temperature resistance and corrosion resistance. The boss, metal bellows, and retaining ring constitute a protective structure. This structure prevents the condensed medium from entering the bushing and causing the bushing and valve stem to jam, and also prevents temperature changes from causing the valve stem and bushing to seize. This protective structure relatively isolates the internal temperature of the valve body from the temperature of the bushing area. The protective structure is located within the installation space and does not obstruct the normal operation of the valve plate.

[0027] like Figure 3As shown, the retaining ring is an arc-shaped bend towards the valve plate. When the valve body is working, the high temperature brought by the high temperature flue gas causes the retaining ring to expand due to heat, and the deformation direction tends to be towards the bushing, so that it fits tightly or even has an interference fit with the installation space, thus isolating the medium from flowing into the valve body.

[0028] In a preferred embodiment of this invention, the boss includes a base 61 and a thickened portion 62. The base is made of the same material as the valve stem, and the thickened portion is made of a polymer material, such as polytetrafluoroethylene or polyetheretherketone. The thickened portion will thermally expand under high-temperature flue gas conditions, and cooperates with the retaining ring to isolate the bushing from the valve body. The boss has an arc shape that bends away from the valve plate, and expands towards the valve plate during expansion. Alternatively, the entire boss can be made of a polymer material.

[0029] In a preferred embodiment of this invention, temperature control mechanisms are installed at both ends of the valve stem located outside the valve body. These mechanisms can be based on a thermocouple and PID controller, a resistance temperature detector (RTD) and intelligent temperature controller, or an infrared temperature sensor and PLC; these are all existing technologies and will not be elaborated upon here. Real-time monitoring of the valve temperature and automatic adjustment of the heating device ensure stable valve operation under any working environment, preventing the valve stem and bushing from seizing together and preventing acid sludge from invading and solidifying in the valve stem and bushing.

[0030] The sealing surface of the valve plate and the sealing surface of the valve body are complementary spherical sections. This allows the sealing surface of the sulfuric acid flue gas combination valve to automatically align with the center of the ball and automatically compensate for wear during over-travel, ensuring sealing performance. At the moment of opening and closing, no friction occurs on the sealing surface. When opening, the projected cross-section of the valve plate continuously retracts inward and backward; initially, the backward retraction is faster than the inward retraction. Different types of materials can be used to handle various working conditions and media, resulting in excellent sealing performance and a long sealing life. Its size and weight are significantly smaller than ball valves, reducing costs. The opening and closing torque is much lower than that of butterfly valves. It achieves zero leakage.

[0031] Each component of this invention, including the valve stem, valve plate, and sealing surface, can be disassembled and replaced individually, avoiding the high cost and complexity of replacing the entire valve and saving maintenance time and economic costs.

[0032] A method for using a sulfuric acid flue gas combination valve includes the following steps: The sulfuric acid flue gas combination valve is connected to a flue gas pipeline. Under high-temperature flue gas conditions, the metal bellows expands and elongates due to heat, pushing the retaining ring towards the valve plate. Simultaneously, the retaining ring expands and interlocks with the installation space to prevent dust from entering the installation space. When the sulfuric acid flue gas combination valve stops working, the metal bellows and retaining ring cool and contract. The contraction of the retaining ring may create a gap with the installation space, while the radial expansion of the metal bellows ensures a tight fit with the installation space, preventing dust from entering the bushing through the gap and providing insulation space for the bushing. Therefore, regardless of whether it is in a high-temperature working environment with high-temperature flue gas or a low-temperature environment after shutdown, and regardless of whether the retaining ring and metal bellows are in a contracted or expanded state, the protective structure always maintains isolation between the valve body and the bushing.

Claims

1. A combined valve for sulfuric acid flue gas, comprising: The valve body (1), valve plate (2), bushing (3) and valve stem (4) are characterized in that: the bushing is installed in the mounting holes (5) at both ends of the valve body, the valve body includes a first valve body (11) and a second valve body (12), the first valve body and the second valve body are closed to accommodate the valve plate and the valve stem, the mating surfaces of the first valve body and the second valve body are respectively provided with flange surfaces (13), the flange surfaces are detachably connected by bolts, and two clamps (14) are provided outside the flange surfaces, the two clamps are symmetrically surrounded around the circumference of the flange surfaces and are connected as one piece by bolts.

2. The sulfuric acid flue gas combination valve as described in claim 1, characterized in that: The mounting hole has a reserved mounting space at one end near the valve plate. One end of the valve stem is provided with a boss (6) located in the mounting space. The end of the boss near the valve plate is connected to a metal bellows (7) that fits the valve stem. The end of the metal bellows is connected to a retaining ring (8) that slides with the valve stem. The retaining ring is made of polymer material.

3. A sulfuric acid flue gas combination valve as described in claim 2, characterized in that: The retaining ring is in the shape of an arc that bends toward the valve plate.

4. A sulfuric acid flue gas combination valve as described in claim 2, characterized in that: The boss includes a base (61) and a thickened part (62). The base is made of the same material as the valve stem, and the thickened part is made of polymer material.

5. A sulfuric acid flue gas combination valve as described in claim 4, characterized in that: The boss is in the shape of an arc that curves away from the valve plate.

6. A sulfuric acid flue gas combination valve as described in claim 2, characterized in that: The boss is made of polymer material and is in the shape of an arc that bends away from the valve plate.

7. A sulfuric acid flue gas combination valve as described in claim 1, characterized in that: Temperature control mechanisms (9) are installed at both ends of the valve stem located outside the valve body.

8. A sulfuric acid flue gas combination valve as described in claim 1, characterized in that: An expansion joint (10) is installed on the outer end face of the first valve body.

9. A sulfuric acid flue gas combination valve as described in claim 1, characterized in that: The sealing surface of the valve plate and the sealing surface of the valve body are complementary spherical tangents.

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