Three-eccentric center butterfly valve suitable for combined soda production device

Abstract

The utility model provides a three-eccentric center butterfly valve suitable for a combined alkali device, which comprises a valve body, a valve shaft and a valve plate are arranged in an inner cavity of the valve body, the valve plate and the valve shaft are connected through a titanium flat key, the valve plate is arranged on the periphery of the valve shaft and rotates around the valve shaft, and an upper bearing is arranged between the valve shaft above the valve plate and the valve body. A lower bearing is arranged between the valve shaft below the valve plate and the valve body, teflon O-shaped rings are installed on the inner sides of the upper bearing and the lower bearing, the teflon O-shaped rings and the outer circle of the valve shaft can form an independent sealing cavity, and media are prevented from entering a gap between the valve shaft and the bearings. And a step part is arranged at the lower end of the valve shaft at the lower end of the lower bearing and provided with a limiting piece, and a bottom flange is arranged at the bottom end of the valve shaft. According to the three-eccentric center butterfly valve suitable for the combined-soda device, the problem of valve failure caused by medium corrosion and existence of medium solid-liquid double phases can be effectively avoided, normal work of the valve is ensured, and normal operation of the combined-soda device is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to a triple-eccentric butterfly valve suitable for a caustic soda device. Background Art

[0002] The products of the combined alkali unit are mainly soda ash, baking soda and ammonium chloride. In the agricultural field, they are used to manufacture fertilizers, pesticides, herbicides and other products. They can also be used as neutralizers, solvents and catalysts in the process of fertilizer manufacturing to help improve the purity and effectiveness of pesticides. In the medical field, combined alkali products are used to manufacture medicines, disinfectants and detergents. In short, combined alkali unit products are widely used in agriculture, industry, medicine and other fields, and are important devices in my country's chemical industry.

[0003] The main components of the ammonia mother liquor medium in the alkali-processing unit are ammonium chloride, sodium chloride, sodium hydroxide, potassium hydroxide and sodium bicarbonate. These chemical components are not only highly corrosive, but also produce crystallization. The temperature of ammonia mother liquor varies in the range of 10℃ to 50℃. When the temperature is lower than 35℃, the ammonia mother liquor will produce crystals within a certain component concentration range. The crystal size of sodium bicarbonate is 50-200μm, and the crystal size of ammonium chloride is 200-500μm. The solid content in the ammonia mother liquor can reach up to 60%; therefore, the ammonia mother liquor medium exists in the situation where liquid and crystal phases switch between each other, or exist at the same time; when the medium penetrates between the valve shaft and the bearing in liquid state, and then converts into crystals under the working conditions of temperature and concentration changes, the change in medium volume can easily cause stress on the valve shaft and bearing, increasing the torque value normally required for the valve, and also causing damage to the valve shaft and bearing parts during the valve operation, eventually causing the valve to become stuck and unable to operate; in addition, the corrosiveness of the ammonia mother liquor medium, coupled with the erosion of the valve trim by the crystals in the medium during the flow, can also easily cause the connection of some parts of the valve trim to fail, thereby causing failures and quality accidents.

[0004] The valve regulates and cuts off the flow of ammonia mother liquor in the pipeline and is an important control unit in the alkali-water unit. Faced with such harsh working conditions, a low-cost, anti-jamming valve is an important guarantee for the smooth production of the alkali-water unit. Summary of the Invention

[0005] To address the shortcomings of the existing technology, the present invention provides a triple-eccentric butterfly valve suitable for a combined alkali plant. This sealing butterfly valve employing this technology can significantly extend the normal service life of the valve's internal components under corrosive conditions while using low-cost raw materials. This prevents valve jamming caused by the crystallization of the medium, extending the valve's service life under medium-flushing conditions, ensuring the valve maintains optimal operating conditions for a long time in the combined alkali plant, and guaranteeing safe and stable operation of the plant.

[0006] The technical solution adopted in this utility model is:

[0007] A triple-eccentric butterfly valve suitable for a joint alkali device, comprising: a valve body, an inner cavity of the valve body is provided with a valve shaft and a valve plate, the valve plate is provided on the periphery of the valve shaft and rotates around the valve shaft, the valve shaft (3) and the valve plate (2) are connected by a flat key, an upper bearing is provided between the valve shaft above the valve plate and the valve body, a lower bearing is provided between the valve shaft below the valve plate and the valve body, a packing group is provided above the upper bearing, a gland assembly is provided at one end of the packing group away from the upper bearing, the gland assembly is connected to the valve body, a step portion is provided at the lower end of the valve shaft below the lower bearing, a limit piece is provided on the step portion, and a bottom flange is provided at the bottom end of the valve shaft.

[0008] Preferably, in the triple-eccentric butterfly valve suitable for the alkali joint device, the valve plate and the valve shaft are axially positioned by positioning bolts; and the flat key is made of titanium alloy.

[0009] Preferably, the three-eccentric butterfly valve suitable for the alkali joint device, wherein: the gland assembly includes a packing pressure plate and a packing gland, a packing gland is provided at one end of the packing group away from the upper bearing, a packing pressure plate is provided at one end of the packing gland away from the packing group, and the packing pressure plate and the valve body are connected by fasteners.

[0010] Preferably, in the triple-eccentric butterfly valve suitable for a combined alkali plant, sealing rings are provided between the packing pad and the valve shaft and between the packing pad and the shaft hole of the valve body.

[0011] Preferably, in the triple-eccentric butterfly valve suitable for a combined alkali plant, a sealing ring is provided between the inner hole of the packing pad and the valve shaft.

[0012] Preferably, the triple-eccentric butterfly valve suitable for the alkali joint device is characterized in that: grooves are provided at both ends of the inner holes of the upper bearing and the lower bearing near the end portions, and sealing rings are provided in the grooves.

[0013] Preferably, in the triple-eccentric butterfly valve suitable for a combined alkali plant, sealing rings and pressure rings are provided between both ends of the valve plate and the valve body.

[0014] Preferably, the triple-eccentric butterfly valve suitable for the alkali joint device, wherein: the sealing ring and the pressure ring are sequentially mounted on the valve plate and fastened by a circle of hexagonal screws provided at the pressure ring.

[0015] Preferably, in the triple-eccentric butterfly valve suitable for the alkali-coated device, the sealing ring is made of a polytetrafluoroethylene-coated material.

[0016] Preferably, the triple-eccentric butterfly valve suitable for the alkali joint device, wherein: the sealing surfaces of the valve body and the sealing ring are provided with an STL alloy layer; the valve body includes positioning stops at the upper and lower ends and a straight flow section in the middle, and the inner cavity of the straight flow section is provided with an STL alloy layer.

[0017] Advantages of this utility model:

[0018] (1) The three-eccentric butterfly valve of the utility model is suitable for the alkali joint device. The valve shaft and the valve plate are connected by a flat key. The flat key is installed inside the valve plate shaft hole and is not easily directly eroded by medium crystals. The flat key is made of titanium alloy with extremely low material cost, which greatly extends the connection effectiveness and service life of the valve internal parts. It can prevent the valve plate and the valve shaft from being connected by a pin, which may cause the pin anti-falling device to fail due to erosion by medium crystals, and the pin interference to cause the valve internal parts to fall off due to corrosion by the medium. It can also prevent the valve plate and the valve shaft from being connected by a spline, which may cause the valve internal parts to fall off due to corrosion by the splines of the valve plate and the valve shaft.

[0019] (2) The utility model is suitable for the triple eccentric butterfly valve of the alkali joint device. The bearings in the triple eccentric butterfly valve are chrome-plated and hardened. O-rings are used to seal the two ends of the bearing and the valve shaft to form a separate sealing chamber, which can effectively prevent the medium from entering the space between the shaft and the bearing in a liquid state and then converting into crystals. During the operation of the valve, the crystal medium is easy to damage the valve shaft and affect the valve operation. The outer PTFE O-ring is used, which has excellent corrosion resistance in the alkali joint medium.

[0020] (3) The three-eccentric butterfly valve of the utility model is suitable for the joint alkali device. The inner and outer circles of the packing pad are provided with grooves, and O-rings are installed to form redundant seals with the packing, meeting the requirements of ISO15848-B level; the valve sealing surface has a smoothness better than 0.4μm, which can effectively prevent crystals from adhering to the sealing surface, effectively protect the cleanliness of the sealing surface, improve the valve life and reduce the valve closing torque value.

[0021] (4) The three-eccentric butterfly valve of the utility model is suitable for the alkali joint device. The straight section of the inner cavity of the valve body is welded with STL alloy to prevent the erosion of the valve cavity by the crystal medium, so as to meet the normal operation of the device within a four-year maintenance cycle. The actuator configuration is selected according to the safety factor of 2 times the valve torque to prevent the accumulation of medium crystals before and after the online valve, which affects the opening and closing of the valve, and ensure the smoothness of the valve opening and closing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural diagram of the utility model structure.

[0023] Figure 2 yes Figure 1 A partial enlarged view of Figure I.

[0024] Figure 3 yes Figure 1 A partial enlarged view of middle II.

[0025] Explanation of the accompanying drawings: 1-valve body; 2-valve plate; 3-valve shaft; 4-packing pressure plate; 5-packing cover; 6-packing group; 7-packing gasket; 8-upper bearing; 9-O-ring; 10-sealing ring; 11-pressure ring; 12-locating bolt; 13-flat key; 14-lower bearing; 15-limiting assembly; 16-adjusting gasket; 17-bottom flange. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] like Figure 1-3 As shown: This embodiment provides a three-eccentric butterfly valve suitable for a joint alkali device, which includes a valve body 1, a valve shaft 3 and a valve plate 2 are arranged in the inner cavity of the valve body 1, the valve plate 2 is arranged on the periphery of the valve shaft 3 and rotates around the valve shaft 3, an upper bearing 8 is arranged between the valve shaft 3 above the valve plate 2 and the valve body 1, a lower bearing 14 is arranged between the valve shaft 3 below the valve plate 2 and the valve body 1, a packing group 6 is arranged above the upper bearing 8, a pressure cover assembly is arranged at the end of the packing group 6 away from the upper bearing 8, the pressure cover assembly is connected to the valve body 1, a step portion is arranged at the lower end of the valve shaft 3 below the lower bearing 14, a limiter 15 is arranged on the step portion to prevent the valve shaft 3 from blowing out, and a bottom flange 17 is arranged at the bottom end of the valve shaft 3.

[0028] The valve plate 2 and the valve shaft 3 are axially positioned by a positioning bolt 12 , and the flat key 13 is made of titanium alloy.

[0029] The gland assembly includes a packing pressure plate 4 and a packing gland 5. The packing gland 5 is provided at one end of the packing group 6 away from the upper bearing 8, and the packing pressure plate 4 is provided at one end of the packing gland 5 away from the packing group 6. The packing pressure plate 4 and the valve body 1 are connected by fasteners.

[0030] A packing pad 7 is arranged between the packing group 6 and the upper bearing 8, and a sealing ring 9 is arranged between the packing pad 7 and the valve shaft 3 and between the packing pad 7 and the axial hole of the valve body 1. The sealing ring 9 between the packing pad 7 and the axial hole of the valve body 1 serves as the first seal at the packing group 6; a sealing ring 9 is arranged between the inner hole of the packing pad 7 and the valve shaft 3 as a dynamic seal, and the outer one serves as a static seal; grooves are arranged at both ends of the inner holes of the upper bearing 8 and the lower bearing 14 near the end, and a sealing ring 9 is arranged in the groove to form a sealed chamber with the valve shaft 3.

[0031] The sealing ring 10 and the pressure ring 11 are sequentially mounted on the valve plate 2 and fastened by a circle of hexagonal screws provided on the pressure ring 11 ; an adjustment pad 16 is provided between the bottom end of the valve shaft 3 and the bottom flange 17 .

[0032] The sealing ring 9 is made of polytetrafluoroethylene coating material; the sealing surface of the sealing ring 10 of the valve body 1 is provided with an STL alloy layer; the valve body 1 includes positioning stops at the upper and lower ends and a straight flow section in the middle, and the inner cavity of the straight flow section is provided with an STL alloy layer.

[0033] The flat key 13 connecting the valve shaft 3 and the valve plate 2 is made of titanium alloy material, the sealing ring 9 is an O-ring, and the O-ring is a PTFE-coated material with outstanding corrosion resistance in the combined alkali medium; the sealing ring 10 adopts an all-metal structure to prevent medium crystals from getting stuck in the interlayer of the sealing ring 10, damaging the sealing surface of the sealing ring 10, and ultimately affecting the valve seal; the valve seat of the valve body 1 and the sealing surface of the sealing ring 10 are welded with STL alloy; the straight flow section of the inner cavity of the valve body 1 is welded with STL alloy to prevent the crystallized medium from eroding the valve internals, thereby ensuring the normal operation of the combined alkali device within a four-year inspection and maintenance cycle.

[0034] In the alkali-coal-fired device, the medium is easily corroded and exists in two phases of liquid and crystal. The medium temperature ranges from 5°C to 40°C. As the concentration, pressure and temperature of the medium change, the liquid and crystal switch with each other. The triple-eccentric butterfly valve of the utility model can effectively avoid the valve failure problem caused by medium corrosion and the existence of two phases of solid and liquid in the medium, ensure the normal operation of the valve, and guarantee the normal operation of the alkali-coal-fired device.

[0035] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the utility model and are not limiting. Although the utility model is described in detail with reference to examples, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A triple eccentric butterfly valve suitable for a caustic soda unit, characterized by: The invention comprises a valve body (1), wherein a valve shaft (3) and a valve plate (2) are arranged in an inner cavity of the valve body (1), the valve shaft (3) and the valve plate (2) are connected via a flat key, the valve plate (2) is arranged on the outer periphery of the valve shaft (3) and rotates around the valve shaft (3), an upper bearing (8) is arranged between the valve shaft (3) above the valve plate (2) and the valve body (1), a lower bearing (14) is arranged between the valve shaft (3) below the valve plate (2) and the valve body (1), a packing group (6) is arranged above the upper bearing (8), a gland assembly is arranged at one end of the packing group (6) away from the upper bearing (8), the gland assembly is connected to the valve body (1), a step portion is arranged at the end of the valve shaft (3) below the lower bearing (14), a stopper (15) is arranged on the step portion, and a bottom flange (17) is arranged at the bottom of the valve shaft (3).

2. The triple eccentric butterfly valve suitable for the alkali-linked device according to claim 1 is characterized in that: The valve plate (2) and the valve shaft (3) are axially positioned by means of positioning bolts (12); the flat key (13) is made of titanium alloy.

3. The triple eccentric butterfly valve suitable for the alkali-linked device according to claim 1 is characterized in that: The gland assembly comprises a packing pressure plate (4) and a packing gland (5); the packing pressure plate (5) is arranged at one end of the packing group (6) away from the upper bearing (8); the packing pressure plate (4) is arranged at one end of the packing gland (5) away from the packing group (6); and the packing pressure plate (4) and the valve body (1) are connected via fasteners.

4. The triple eccentric butterfly valve suitable for the alkali-linked device according to claim 1 is characterized in that: A packing pad (7) is arranged between the packing group (6) and the upper bearing (8), and a sealing ring (9) is arranged between the packing pad (7) and the valve shaft (3) and between the packing pad (7) and the shaft hole of the valve body (1).

5. The triple eccentric butterfly valve suitable for the alkali-linked device according to claim 4 is characterized in that: A sealing ring (9) is provided between the inner hole of the packing pad (7) and the valve shaft (3).

6. The triple eccentric butterfly valve suitable for the alkali-solution unit according to claim 1, characterized in that: Grooves are arranged at both ends of the inner holes of the upper bearing (8) and the lower bearing (14) near the end, and sealing rings (9) are arranged in the grooves.

7. The triple eccentric butterfly valve suitable for the alkali-solution unit according to claim 1, characterized in that: The sealing ring (10) and the pressing ring (11) are sequentially mounted on the valve plate (2) and fastened by a circle of hexagon socket screws provided on the pressing ring (11).

8. The triple eccentric butterfly valve suitable for the alkali-linked device according to claim 1, characterized in that: An adjustment pad (16) is provided between the bottom end of the valve shaft (3) and the bottom flange (17).

9. The triple eccentric butterfly valve suitable for a combined alkali plant according to any one of claims 4 to 6, characterized in that: The sealing ring (9) is made of a polytetrafluoroethylene coated material.

10. The triple eccentric butterfly valve suitable for the alkali-solution unit according to claim 7, characterized in that: The sealing surfaces of the valve body (1) and the sealing ring (10) are provided with STL alloy layers; the valve body (1) comprises positioning stoppers at upper and lower ends and a straight flow section in the middle, and the inner cavity of the straight flow section is provided with the STL alloy layer.

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