CN112923082A - Movable stuffing box and application thereof in valve - Google Patents

Abstract

The invention discloses a movable stuffing box and application thereof in a valve. The movable stuffing box is arranged at the inlet and outlet end sides of the valve plate on the valve body and comprises a box body, sealing stuffing, a flange gland and a fastener, wherein flanges are arranged at two ends of the box body; the flange a at one end far away from the valve body is connected with the flange gland through a fastener; a pipe sleeve is arranged between the flange b close to one end of the valve body and the valve body; the inner size of the pipe sleeve is larger than the size of the valve plate entering and exiting from the end side of the valve body, one end of the pipe sleeve is fixed at the entering and exiting end side of the valve plate of the valve body, and the other end of the pipe sleeve is provided with a flange c; a sealing ring is clamped between the flange b and the flange c and is connected through a fastening piece; the connecting hole on the flange c is a long hole S, and the long edge of the connecting hole is along the axial direction of the valve body. The movable stuffing box can be widely applied to gate valves and glasses valves, is simple in structure and easy to manufacture, and particularly can effectively guarantee that the valve plate and the valve seat are compressed everywhere and avoid the interference phenomenon of the traditional fixed stuffing box when the valve plate is compressed.

Description

Movable stuffing box and application thereof in valve

Technical Field

The invention relates to a movable stuffing box and application thereof in a valve, in particular to a gate valve and a glasses valve with the movable stuffing box.

Background

The valve is a control part in a fluid conveying system and has the functions of stopping, adjusting, guiding, preventing counter flow, stabilizing pressure, shunting or overflowing and relieving pressure and the like. The variety and specification are various.

The sealing performance of the valve refers to the capability of each sealing part of the valve for preventing medium leakage, and is the most important technical performance index of the valve. The sealing part of the valve has three parts: the contact part between the opening and closing piece and the two sealing surfaces of the valve seat; the matching part of the packing, the valve rod and the packing box; the valve body is connected with the valve cover. Where the former leak is called an internal leak, known as a leak that is not tight, it will affect the ability of the valve to shut off the media. Internal leakage is not allowed for shut-off valves and the like. The latter two leaks are called external leaks, i.e. leakage of medium from the inside of the valve to the outside of the valve. The leakage can cause material loss and environmental pollution, and can also cause accidents in serious cases. For flammable and explosive, toxic or radioactive media, leakage is not allowed, and the valve must have reliable sealing performance. Cuminum cyminum is used for obtaining excellent sealing performance, and the result is difficult to satisfy.

Valves used in many occasions, such as cigarette machine entrances and exits used in oil refineries, some desulfurization systems, sulfur recovery systems and the like, are arranged according to the requirements of the state on environmental protection: the leakage is zero or is a standard class VI seal in the united states. For larger valve sizes, it is difficult to meet this standard. At high temperatures, this is more difficult to achieve. Such as: the inlet valve of high-temperature smoke machine is used for designing smoke gas field with 700 deg.C of temp., its diameter is up to 1850, and its technological requirement is zero leakage. The butterfly valve manufactured by the German Adam company has the selling price of more than 50-60 ten thousand dollars per unit, has larger size and higher temperature, even exceeds ten million RMB, for example, the butterfly valve imported from Germany has the design temperature of 680 ℃ and the design temperature of DN2400 has the selling price of 1200 ten thousand RMB. The price of the butterfly valve manufactured in China also reaches 100-300 ten thousand yuan per butterfly valve. Even so, after a period of use, because of the scouring and wearing of medium, all have the problem of not tight seal and leakage.

Still some domestic refinery's catalytic system, flue gas temperature 680 many degrees, in order to realize zero leakage, adopt the method of water-sealed tank to realize sealed, adopt this kind of sealed mode, its drawback includes:

1. the pressure loss is large, the energy consumption is increased: the smoke returns to an outlet above the outer cylinder from the lower part of the inner cylinder and is bent by two bends, so that the pressure loss is large;

2. the investment is large: about 100 to 300 ten thousand yuan;

3. the occupied area is large: land resources are wasted due to extra occupied land;

4. environmental pollution: the water for water sealing is polluted by the flue gas to form acidic water, and if the acidic water is directly discharged, the environment is polluted, and if the acidic water is discharged after treatment, the treatment cost is high;

5. high use and maintenance costs: the flue gas is hot, the anti-freezing is considered, water needs to be circulated, a whole set of control system is needed, anti-freezing heat preservation measures need to be adopted in some cold regions, water needs to be supplemented in operation, the maintenance and the maintenance of the equipment need about 8-10% of the investment amount every year, and the operation cost of the equipment needs tens of thousands yuan every year;

6. reliability is worse than valve: the water seal system uses more types of equipment and instruments, and increases fault points, so the reliability is poor; in addition, the inner barrel is corroded after the high-temperature sulfur-containing flue gas reacts with water, so that the inner barrel is easy to fall off, and the problem that the inner barrel falls off after several times of reaction in China already occurs.

Many water-sealed tanks are adopted in the gas field, and anti-freezing measures are required, so that the corresponding cost and problems are undoubtedly increased.

In order to realize zero emission, other enterprises adopt measures of a butterfly valve with a double-layer structure or a blower positive pressure ventilation between two gate valves to realize zero leakage, the structure is complex, the manufacturing cost is high, the size of a valve used in the occasion is often large, the deformation caused by the temperature, the medium pressure and the like in the manufacturing, transporting, installing and using processes is large, the zero leakage is very difficult to realize, the deformation caused by various reasons is large, an air curtain formed by the blower ventilation between the butterfly valve with the double-layer structure or the two gate valves is sealed, the air quantity required by the blower positive pressure ventilation is large, and the long-term power consumption is large, so the energy consumption is large. In addition, according to the requirements of national standards or ministerial standards, when sealing is realized by using sealing air, the sealing air needs to be heated to more than 100 ℃, the hot sealing air is blown away at any time, the energy consumption is huge, the hot sealing air is equivalent to steam, a large amount of water can be formed in a pipeline, the equipment and the pipeline are corroded after the hot sealing air reacts with harmful media, caking, scaling and crystallization are formed after the hot sealing air is mixed with dust, the sealing and the opening and closing of a valve are further seriously influenced, and the example cannot be taken out. The applicant has entered into several desulfurization flues, which are referred to above. The applicant has also studied a variety of valves and used the studied valves in a variety of different situations, where the experience is considerable for various drawbacks.

For example, the Chinese patent "flue gas baffle door and its sealing device, No. CN 201526980U", uses inflatable sealing tube to realize sealing, and its disadvantages are that the sealing is made of rubber material, it is not high temperature resistant, and the sealing material is easy to age. The same problem exists with the sealing structure of chinese patent "gate valve, application publication No. CN 104006176A".

The anti-explosion electric open-type gate valve has the advantage of good sealing performance like the Chinese patent No. CN 204592362U. Its disadvantages are also prominent, including:

1. the pressure loss is large, and the energy consumption is increased: in order to ensure that the sealing surface is not washed away, the sealing surface is protected by a method of reducing the caliber of the valve, so that the pressure loss of the valve is increased, and the energy consumption is increased;

2. the structure is complicated, and manufacturing cost is high, and influences the use reliability: compared with the conventional gate valve, the gate valve additionally increases a valve seat (piston type valve seat) and a valve seat sleeve, and according to common knowledge, when an actuating mechanism of a piston is required to be lost, even a large-size valve can require a plurality of sets, so that the structure is complex, and the manufacturing cost is increased: if the alloy is used in high-temperature occasions, high alloy steel is needed, so that the cost of raw materials is increased; and the valve seat sleeve can generate relative motion; when the sizes of the valve seat and the valve seat sleeve are larger or impurities enter between the valve seat and the valve seat sleeve, the valve seat and the valve seat sleeve are easy to clamp; the valve cover 4 is used for accommodating the valve cover 4 which is inserted in and out of the inserting plate 2, the valve cover 4 is equivalent to a box body, namely, a plurality of box bodies are arranged compared with a conventional inserting plate valve, the box body not only increases the manufacturing cost, but also has a dead zone in the box body and is easy to deposit dust, when the valve cover is used for a smoke medium containing sulfur, the cold and hot walls in the box body are easy to dewe, water formed by dewing reacts with the smoke to form a corrosive medium to corrode equipment, and meanwhile, the formed water can agglomerate, scale and crystallize with dust in the smoke to seriously affect the opening and closing and sealing of the valve, and at the moment, the valve seat and the valve seat sleeve are possibly blocked due to the agglomeration; for another example, the valve seat below the valve body forms a groove, and the groove is used for influencing the closing of the valve after dust is accumulated in the groove. After entering the groove, the dewed water is easy to agglomerate, scale, crystallize and even freeze with dust in the medium; the above-mentioned various problems naturally affect the reliability of use, as well as making the structure complicated, making it difficult and expensive to manufacture.

For another example, the chinese patent "a two-way sealing knife gate valve, grant publication No. CN 203453505U", has the advantages of novel conception, and its disadvantages are highlighted as follows:

1. various factors in the practical application process result in the failure to achieve a truly effective seal: firstly, when the gate valve is connected with a pipeline on site, if the movable elastic sealing sleeve is in the pipeline, the pressing force of the sealing ring and the sealing sleeve cannot be adjusted. This is particularly true for valves of large dimensions (which are almost non-deformable in field installations and which, in addition to the deformations caused by the various factors mentioned above), which tend to displace the upper part of the movable elastic sleeve 3 axially outwards if the outer axial end face of the elastic sealing sleeve 3 is connected to a pipe in the field, since this part of the upper part is the weakest, with the result that: the upper part of the sealing ring can not be contacted with the valve plate, and the upper part of the sealing ring on the other side can be the same, at the moment, the sealing ring is difficult to be pressed by the elastic sealing sleeve through a screw, and particularly, after the valve body is twisted and deformed, the sealing effect is not mentioned; secondly, in a high-temperature situation, the sealing filler cannot be made of rubber, usually a graphite packing is adopted, for example, the sealing filler below the screw 9 and the sealing ring 10 in the figure 2 in the specification are both made of graphite packing, when the sealing ring 10 is worn, if the sealing ring is pressed by an elastic sealing sleeve, the sealing filler below the screw 9 is not worn, and the interference problem during pressing is generated, so that the sealing is difficult to realize in fact, and the sealing cannot be realized; furthermore, the diameter of the valve rod 6 is usually dozens of millimeters, the diameter of the valve rod nut 11 is larger than that of the valve rod 6, and the thickness of a valve cover plate connected with the movable elastic sealing sleeve is added, so that the axial length of the movable elastic sealing sleeve is longer, the axial rigidity of the movable elastic sealing sleeve is larger, the elasticity is poor, and the sealing ring 10 and the sealing ring 8 on the other side are difficult to be pressed everywhere; similarly, it has been found that when the valve body is torsionally deformed and is hardly fully compressed, the seal is not mentioned.

2. The machining position is many, and the structure is complicated, and is with high costs and the reliability of using is difficult to guarantee: the same as the former patent, the valve body below the groove brought after the deposition influence the valve close, the water of dewing gets into this groove after easily with the dust caking in the medium, scale deposit, crystallization, probably even freeze the problem that the reliability is used to serious influence such as.

In fact, many gate valves at home and abroad are similar to the structure and have the technical problems.

A single plate eye valve (open type) manufactured by Deenjie, Germany (ZMMERMANN & JANSEN) and SchuF and Staphylotricha Kogyo of Tianjin, China, as shown in FIG. 1, is provided with an expansion joint for compression. The double-plate eye valve (closed type) manufactured by the two-plate eye valves is characterized in that two similar box bodies are symmetrically fixed on two sides of the axial line outside the valve body respectively, and as shown in figure 2, the double-plate eye valve has the problems of complicated structure, increased manufacturing cost, dust accumulation and condensation in the box bodies and the like as the anti-explosion electric open type gate valve in the Chinese patent with the same authorization publication number CN 204592362U; meanwhile, two sides of the eye valve with the structure are provided with the sealing cavities, when the eye valve is large in size, the end sockets are required to be adopted, N actuating mechanisms for compressing the valve plate are arranged outside the valve body, the whole eye valve is particularly heavy and natural, the manufacturing cost, the transportation cost, the installation cost, the maintenance cost and the like are correspondingly improved, and the use reliability is inevitably reduced.

The SchuF company also manufactures an eye valve combining an open type and a closed type, which is based on fig. 2, and a guide rail is fixed above the valve, the two side sealed cavities are hung on the guide rail, and the two side sealed cavities can be separated from each other, so that the structure has the advantages that: after the sealing cavity is opened, internal leakage cannot be generated, and external leakage can be checked. It has the following disadvantages: besides the problems of the eye valve, the space occupied by the opened sealing cavity is very large, which is equivalent to the width of 4-5 valve bodies, and the sealing surfaces and the guide rails of the two valve bodies and the sealing cavity are also increased. When the valve is closed, the sealed cavity must be opened to prevent internal leakage, and if the medium in the cavity is toxic or inflammable, potential safety hazards exist, and troublesome measures need to be taken. After the sealing cavity is opened, sundries can enter the cavity or the sealing surface and the sealing surface of the valve body are frozen, so that the use reliability is influenced, and the soft seal between the sealing cavity and the valve body can be damaged.

In addition, other types of valves, such as a flue damper hinge four-bar sealing mechanism with an authorization notice number CN201100649U and a four-bar sealing door with an authorization notice number CN202165597U in Chinese patents, occupy less space, have simple structure and good sealing effect compared with the existing gate valve. But the following disadvantages exist at the same time:

1. the manufacturing precision and the deformation caused by manufacturing, transportation, installation and use make the realization of zero leakage difficult, and when the size is large, the deformation which cannot be avoided makes the realization of zero leakage more difficult; the position precision requirement of the four connecting rods is strict; the four connecting rods are different in length, and the valve plate and the valve seat are easy to displace due to different thermal deformation, so that a gap is easy to generate to influence the sealing effect;

2. the four-bar mechanism in the flue is provided with a plurality of friction pairs, when the medium in the flue contains dust, the friction pairs are easy to clamp, particularly after the medium is condensed, the medium and the dust form blocks and scales, and the friction pairs are easy to clamp or lock. Therefore, production stop is easy to cause, and loss is brought.

3. When the four-bar mechanism is used in a high-temperature occasion, expensive high-alloy steel is needed to be adopted for the four-bar mechanism, so that the four-bar mechanism is high in manufacturing cost. In some high temperature occasions, the valve body is required to be internally provided with a heat-insulating and wear-resisting lining, such as: the medium temperature is 680 ℃, namely the temperature borne by the valve internal part is 680 ℃, after the heat-insulating lining is arranged, the temperature of the valve body is less than 200 ℃, and the expansion difference between the annular valve seat and the valve body in the valve body exceeds 1%, so that a top between the valve plate and the valve body is pushed, and the valve plate and the valve body generate yielding or high-temperature creep deformation, thereby affecting sealing.

The environmental protection does not reach the standard due to the untight sealing of the valve; and hot flue gas can flow backward, so the fan is corroded on one hand, and manpower cannot enter the flue for construction on the other hand.

As can be seen, the problem of sealing valves has been a technical problem in the art, especially for large size valves. The method comprises the steps of machining and manufacturing precision, deformation caused by transportation and installation, deformation caused by medium temperature and pressure in the using process, influence on sealing caused by dust deposition or impurities on a valve seat in the using process and scouring and abrasion of particles in the medium on a sealing surface, and the like.

Disclosure of Invention

In view of the above problems in the prior art, the present invention is directed to a movable stuffing box, and discloses application of the movable stuffing box to gate valves and eye valves, for example, to solve the sealing problem caused by interference when the gate valves are closed by a pressing mechanism and to solve the problems of complicated structure and high cost caused by the sealing of the two-plate eye valves.

The technical solution of the invention is realized as follows:

a movable stuffing box is arranged at the inlet and outlet end sides of a valve plate on a valve body and comprises a box body with a flange, sealing stuffing, a flange gland and a fastener;

two ends of the box body are provided with flanges; the flange a at one end far away from the valve body is connected with the flange gland through a fastener; a pipe sleeve is arranged between the flange b close to one end of the valve body and the valve body;

the inner size of the pipe sleeve is larger than the size of the valve plate entering and exiting from the end side of the valve body; one end of the pipe sleeve is fixed at the inlet and outlet end sides of the valve plate of the valve body, and the other end of the pipe sleeve is provided with a flange c; a sealing ring is clamped between the flange b and the flange c and is connected through a fastening piece; specifically, the sleeve is of a square tube structure;

the connecting hole on the flange c is a long hole S, the long edge of the long hole S is along the axis direction of the valve body, and the size of the long hole S is larger than the outer diameter of a fastener matched with the long hole S.

Preferably, in order to improve the moving flexibility of the movable stuffing box, the stuffing box further comprises a movable flange and an antifriction structure;

the movable flange is sleeved on the periphery of the pipe sleeve, is parallel to the flange c and is positioned between the flange c and the valve body; specifically, the movable flange is a rectangular annular structure corresponding to the sleeve of the square tube structure;

the antifriction structure is clamped between the movable flange and the flange c;

the flange b, the flange c, the antifriction structure and the movable flange are connected in sequence through fasteners.

Specifically, the sealing filler and the sealing ring are made of rubber, graphite packing, oil-immersed packing or polytetrafluoroethylene;

the antifriction structure adopts graphite packing, oil immersion packing, polytetrafluoroethylene board or equipartition N universal ball in plane.

The invention also discloses a valve with the movable stuffing box.

Specifically, the valve may be a gate valve.

Alternatively, the valve can be a double-plate glasses valve; the stuffing box is arranged on the end side of the valve body corresponding to the valve plate entering the valve body direction; the sealing cavity is opposite to the stuffing box and fixed on the end side of the valve body corresponding to the direction of the valve plate away from the valve body so as to accommodate the opened valve plate.

Further, for the double-plate glasses valve, in order to avoid the medium from contacting with the inner wall of the sealed cavity for a long time, the stuffing box comprises a first stuffing box and a second stuffing box, the first stuffing box and the second stuffing box are symmetrically arranged at two inlet and outlet end sides of the valve plate of the valve body, the first stuffing box is positioned at the end side of the valve body corresponding to the direction that the valve plate enters the valve body, and the second stuffing box is positioned at the end side of the valve body corresponding to the direction that the valve plate leaves the valve body; and the sealing cavity is fixed on the flange gland of the second stuffing box.

Further, the valve further comprises a compensator; the valve plate is fixed on the valve body and positioned on one side of the valve plate close to the valve seat, and the axis of the valve plate is parallel to the axis of the valve body; and under the condition that the pressing mechanism of the valve plate is loosened, a piston rod of the compensator abuts against a flange b of the stuffing box to push the valve plate to leave the valve seat. In particular, the compensator is a pneumatic actuator.

Further, in order to ensure the sealing effect, a groove is formed in the axial surface of the valve seat of the valve body, and sealing filler is contained in the groove; specifically, the sealing filler extends out of the axial sealing surfaces of the groove and the valve seat to ensure the sealing effect.

Preferably, the groove is in a narrow-mouth wide-belly shape, such as a dovetail groove.

Further, under the valve opening state, a distance larger than the axial displacement of the valve plate exists between the valve plate and the inner wall of the sleeve.

Specifically, the compressing mechanism of the valve plate is fixed on the valve body and comprises a plurality of sets of straight stroke air cylinders or oil cylinders with piston rods, the straight stroke air cylinders or the oil cylinders are evenly arranged right opposite to the periphery of the valve seat, and the piston rods of the compressing mechanism are perpendicular to the valve plate and extend into the valve body.

The valve plate is internally provided with an electric heater for solving the problems of corrosion, scaling, caking and crystallization caused by dew condensation on cold and hot walls in the existing gate valve and eye valve, and then the sealing and closing of the valve are influenced.

The working principle of the invention is as follows:

1. when the valve is applied to a horizontal pipeline, the valve plate of the valve is vertical to the ground, after the valve plate is sent to a valve closing position (usually positioned at the lower part) by the actuating mechanism a, the actuating mechanism b drives the shaft to rotate, the cam fixed on the shaft pushes the valve plate to generate displacement towards the direction of the valve seat, and finally the valve plate is pressed on the valve seat; in the displacement process of the valve plate, the stuffing box can be driven to synchronously displace; after the actuating mechanism b is released, the stuffing box is pushed by the compensator to move back to the initial position before closing and the valve plate is driven to leave the valve seat.

2. When the valve is applied to a vertical pipeline, the valve plate of the valve is parallel to the ground, the valve plate is positioned below the valve seat, after the valve plate is sent to the valve closing position by the actuating mechanism a, the actuating mechanism b drives the shaft to rotate, the cam fixed on the shaft pushes the valve plate to generate displacement towards the valve seat, and finally the valve plate is pressed on the valve seat; in the displacement process of the valve plate, the stuffing box can be driven to synchronously displace; and after the actuating mechanism b is released, the stuffing box is pushed to move back to the initial position before closing by the self weight of the valve plate and the valve plate is driven to be far away from the valve seat. The self weight of the valve plate can move the stuffing box back to the initial position, so that a compensator can be omitted when the stuffing box is applied to the occasion.

Compared with the prior art, the invention has the advantages that:

the movable stuffing box disclosed by the invention effectively ensures that the valve plate and the valve seat are compressed everywhere, avoids the interference phenomenon of the traditional fixed stuffing box when the valve plate is compressed, thereby ensuring that the valve plate and the valve seat are closely attached everywhere, ensuring the sealing performance and the sealing effect, combining the soft and hard sealing modes, and solving the problem that zero leakage is difficult to realize after a large-size gate valve or an eye valve is deformed in the prior art. Meanwhile, the requirement on the manufacturing precision of the valve is reduced, and the manufacturing cost is reduced.

Meanwhile, compared with various existing valve products, the valve mainly comprises a gate valve and a double-plate glasses valve, and has the characteristics of simple structure, easiness in manufacturing, convenience in use and substantial cost saving on the premise of ensuring the sealing performance, and undoubtedly better meets the requirements and expectations of customers:

for example, compared with the existing double-gate valve, the valve disclosed by the invention is equal to one valve and various actuating mechanisms of the valve, so that the cost is greatly reduced, and particularly, high alloy steel used in high-temperature occasions is very expensive, such as 06Cr25Ni20 steel, the price is 4-8 ten thousand yuan/ton, so that the manufacturing cost is greatly reduced, and the burden of a user is lightened. In addition, the double gate valve requires sealing air to be communicated between the two gates, thereby increasing the operation cost. There are occasions when hot sealing air is required, which further increases the operating costs. After hot sealing air is introduced, condensation is often formed in the pipeline to form a large amount of water, and when the medium is sulfur-containing flue gas, the water reacts with sulfur to form a medium with extremely high corrosivity to corrode a flue or a heat-insulating lining.

For example, compared with a four-bar linkage actuating mechanism, the four-bar linkage actuating mechanism has the problems that a plurality of movable parts are available, lubrication cannot be realized, a rotary friction pair is easy to block, maintenance cannot be realized without dismounting, the reliability is poor, sealing is not tight, the pressure is high, the four-bar linkage actuating mechanism is difficult to open when the size is large, and the like; it is clear that the use of the present invention makes the above problem easy to solve.

By using the double-plate glasses valve disclosed by the invention, sulfur-containing smoke can not exist or not exist in the sealed cavity for a long time, so that the valve is not easy to dewing, scaling, caking and crystallization, the flexibility and reliability of opening and closing are ensured, the sealing performance is also ensured, and the use reliability is improved. Meanwhile, the water after condensation reacts with the medium to corrode the valve and the pipeline or the heat-insulating lining.

Meanwhile, the structure of the invention can ensure that the problems of switch jam or poor sealing can not occur even if the valve is deformed greatly after being installed.

Moreover, the valve disclosed by the invention does not need a corrugated pipe on a blind plate valve, so that the problem that the service life of the corrugated pipe is influenced due to the fragile corrugated pipe is avoided.

Drawings

Fig. 1 is a schematic structural view of a movable stuffing box according to embodiment 1 of the present invention;

FIG. 2 is a schematic structural view of a gate valve according to embodiment 2 of the present invention in vertical use;

FIG. 3 is a cross-sectional view A-A of FIG. 2;

FIG. 4 is a schematic structural view of a gate valve according to embodiment 2 of the present invention in horizontal use;

FIG. 5 is a schematic structural view of a two-plate eye valve I according to embodiment 3 of the present invention;

FIG. 6 is a schematic structural view of a two-plate eye valve II according to embodiment 4 of the present invention.

In the figure: 1. the valve comprises a valve body 2, a valve plate 3, a valve seat 4, a flange cover 402, a flange a 403, a box body 404, sealing filler 405, a flange b 406, a flange c 407, a sealing ring 408, a sleeve 409, a movable flange 410, antifriction structures 411 and 412, fasteners 5, a compensator 6, a sealing cavity 7, an electric heater 8, an actuator a 801, an actuator bracket 9, a pressing mechanism 901, an actuator b 902, a shaft 903, a shaft sealing mechanism 904 and a cam 10.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings.

Example 1: movable stuffing box

A movable stuffing box 4 according to the present invention, as shown in fig. 1, is provided at the end side of the valve plate 2 on the valve body 1, and includes a flanged box 403, a packing seal 404, a flange cover 401, and a fastener;

two ends of the box body 403 are provided with flanges; wherein, the flange a402 at one end far from the valve body is connected with the flange gland 401 through a fastener 412; a pipe sleeve 408 is arranged between the flange b405 at one end close to the valve body and the valve body 1;

the inner dimension of the sleeve 408 is larger than the dimension of the valve plate 2 entering and exiting the end side of the valve body; one end of the pipe sleeve 408 is fixed on the end side of the valve plate of the valve body 1 which is inserted and removed, and the other end is provided with a flange c 406; a sealing ring 407 is clamped between the flange b405 and the flange c406 and is connected through a fastener 411; specifically, the sleeve 408 is of a square tube structure; in the valve opening state, a distance larger than the axial displacement of the valve plate exists between the valve plate 2 and the inner wall of the sleeve 408.

Both of the fasteners 411, 412 may be screw and nut structures.

In order to ensure the smooth movement and movement of the stuffing box, the connecting hole on the flange c406 is a long hole S, the long edge of the long hole S is along the axial direction of the valve body 1, and the size of the long hole S is larger than the outer diameter of the fastener 411 matched with the long hole S.

In this way, a movable stuffing box 4 is formed.

In order to improve the movement flexibility of the movable stuffing box 4, the stuffing box 4 can be further provided with a movable flange 409 and an antifriction structure 410;

the movable flange 409 is sleeved on the periphery of the pipe sleeve 408, is parallel to the flange c406 and is positioned between the flange c406 and the valve body 1; specifically, the movable flange 409 may generally adopt a rectangular annular structure corresponding to the sleeve 408 of the square tube structure;

the friction reducing structure 410 is sandwiched between the movable flange 409 and the flange c406 to improve the flexibility of the stuffing box 4 in moving;

the flange b405, the flange c406, the friction reducing structure 410 and the movable flange 409 are connected in sequence by fasteners 411.

The movable stuffing box 4 can be widely applied to various valves including a gate valve, a glasses valve and the like, for example:

example 2: gate valve

A gate valve, as shown in figures 2-4, comprises a valve body 1, a valve plate 2, a valve seat 3, a movable stuffing box 4, an actuator a8, a pressing mechanism 9 of the valve plate, and a compensator 5; the valve body 1 is fixed with the actuating mechanism bracket 801 and the pressing mechanism 9 together, the valve seat is connected to the valve body 1, and the actuating mechanism a is connected with the valve plate 2;

the pressing mechanism of the valve plate is fixed on the valve body and comprises an actuating mechanism b901, a shaft 902, a shaft seal mechanism 903 and a cam 904 fixed on the shaft 902, wherein the actuating mechanism comprises a plurality of sets of straight stroke cylinders or oil cylinders with piston rods, the straight stroke cylinders or the oil cylinders are evenly arranged right opposite to the periphery of the valve seat, and the piston rods of the actuating mechanism are perpendicular to the valve plate and extend into the valve body.

The stuffing box 4 is arranged at the end side of the valve plate 2 on the valve body 1, and the structure and installation thereof are as described in embodiment 1, which is not repeated;

when the valve is applied to a horizontal pipeline, the valve plate 2 is vertical to the ground, as shown in fig. 2 and 3, after the actuator a8 sends the valve plate 2 to a valve closing position (normally located at the lower part) in the valve body 1, the actuator b901 drives the shaft 902 to rotate, the cam 904 fixed on the shaft 902 pushes the valve plate 2 to generate displacement towards the valve seat 3, and finally the valve plate 2 is pressed on the valve seat 3; in the displacement process of the valve plate 2, the stuffing box 4 is driven to synchronously displace; after the actuator b901 is released, the stuffing box 4 is pushed by the compensator 5 to move back to the initial position before closing and to bring the valve plate 2 away from the valve seat 3.

When the valve is applied to a vertical pipeline, the valve plate is parallel to the ground, as shown in fig. 4, the valve plate 2 is positioned below the valve seat 3, after the actuator a8 sends the valve plate 2 to the position where the valve is closed in the valve body 1, the actuator b901 drives the shaft 902 to rotate, the cam 904 fixed on the shaft 902 pushes the valve plate 2 to generate displacement towards the valve seat 3, and finally the valve plate 2 is pressed on the valve seat 3; in the displacement process of the valve plate 2, the stuffing box 4 is driven to synchronously displace; after the actuating mechanism b901 is released, the stuffing box 4 is pushed to move back to the initial position before closing by the self weight of the valve plate 2 and the valve plate 2 is driven to be far away from the valve seat 3. In this application, the compensator 5 may not be used in conjunction with the valve plate 2, since the self-weight of said valve plate may move the stuffing box 4 back to the starting position.

Typically, the compensator 5 is a hydraulic compensator with an accumulator, and a pneumatic actuator may be used.

The actuator a8 can adopt a straight stroke air cylinder or an oil cylinder.

The actuator b901 may adopt a pneumatic actuator or an electric actuator.

The cam 904 may be configured with an archimedes spiral or involute profile.

In order to ensure the sealing effect, a groove is usually formed on the axial surface of the valve seat 3, and if a dovetail groove is formed, the sealing filler 10 is accommodated in the dovetail groove, and when the sealing device is used, the sealing filler 10 extends out of the groove and the axial sealing surface of the valve seat to ensure the sealing effect.

The sealing ring 407 and the sealing packing 404, 10 are made of rubber, graphite packing, oil-impregnated packing or polytetrafluoroethylene.

The antifriction structure 410 adopts one of graphite packing, oil immersion packing, polytetrafluoroethylene board or evenly distributed N plane universal balls.

In order to further solve the problems of corrosion, scaling, agglomeration and crystallization caused by dew condensation on cold and hot walls in the existing gate valve and eye valve, which affect the sealing and closing of the valve, an electric heater 7 is arranged in the valve plate 2 of the valve.

Example 3: double plate glasses valve I

A two-plate ocular valve I, as shown in fig. 5, comprising: the valve comprises a valve body 1, a valve plate 2, a valve seat 3, a movable stuffing box 4, a compensator 5, a seal cavity 6, an actuating mechanism a8, an actuating mechanism support 801 and a pressing mechanism 9 of the valve plate.

The stuffing box 4 is arranged at the end side of the valve body 1 corresponding to the valve plate 2 entering the valve body direction;

the seal cavity 6 is opposite to the stuffing box 4 and fixed on the end side of the valve body 1 corresponding to the direction of the valve plate 2 away from the valve body to accommodate the opened valve plate 2.

The structure of the stuffing box 4 and the operation and principle thereof are as described in embodiment 1 and embodiment 2, and detailed description thereof is omitted.

Example 4: double plate glasses valve II

A double-plate spectacle valve II, as shown in fig. 6, is different from embodiment 3 in that the spectacle valve II is provided with two movable stuffing boxes, namely a first stuffing box 4 and a second stuffing box 4 ', which are symmetrically arranged at two end sides of the valve plate inlet and outlet of the valve body 1, the first stuffing box 4 is positioned at the end side of the valve body 1 corresponding to the valve plate 2 entering the valve body direction, namely the stuffing box in embodiment 3, and the second stuffing box 4' is positioned at the end side of the valve body 1 corresponding to the valve plate 2 leaving the valve body direction;

correspondingly, the seal housing 6 is fixed to the flange cover 401 'of the second stuffing box 4'.

The second stuffing box 4' is also a movable stuffing box, the structure and the working way and principle of which are the same as those of the first stuffing box 4, as described in embodiment 1 and embodiment 2; the synchronous displacement of the second stuffing box 4' along with the displacement of the valve plate 2 relative to the valve seat 3 effectively avoids the medium from contacting the inner wall of the sealed chamber 6 for a long time.

Although the present invention has been described with reference to a preferred embodiment, many applications or various valves may be used, but the scope of the present invention is not limited thereto, and is not limited to a gate valve and a four-bar mechanism sealing door.

Claims (10)

1. The utility model provides a mobilizable stuffing box, sets up the distolateral side of valve plate business turn over on the valve body, including the box of flanged, sealed packing, flange gland and fastener, its characterized in that:

two ends of the box body are provided with flanges; the flange a at one end far away from the valve body is connected with the flange gland through a fastener; a pipe sleeve is arranged between the flange b close to one end of the valve body and the valve body;

the inner size of the pipe sleeve is larger than the size of the valve plate entering and exiting from the end side of the valve body; one end of the pipe sleeve is fixed at the inlet and outlet end sides of the valve plate of the valve body, and the other end of the pipe sleeve is provided with a flange c; a sealing ring is clamped between the flange b and the flange c and is connected through a fastening piece;

the connecting hole on the flange c is a long hole S, the long edge of the long hole S is along the axis direction of the valve body, and the size of the long hole S is larger than the outer diameter of a fastener matched with the long hole S.

2. A stuffing box according to claim 1 wherein:

the anti-friction structure also comprises a movable flange and an anti-friction structure;

the movable flange is sleeved on the periphery of the pipe sleeve, is parallel to the flange c and is positioned between the flange c and the valve body;

the antifriction structure is clamped between the movable flange and the flange c;

the flange b, the flange c, the antifriction structure and the movable flange are connected in sequence through fasteners.

3. A stuffing box according to claim 2, wherein:

the sealing filler and the sealing ring are made of rubber, graphite packing, oil-immersed packing or polytetrafluoroethylene;

the antifriction structure adopts graphite packing, oil immersion packing, polytetrafluoroethylene board or equipartition N universal ball in plane.

4. A valve having a removable stuffing box according to claim 1 or 2.

5. The valve of claim 4, being a gate valve.

6. The valve of claim 4, being a dual plate spectacle valve, wherein:

the stuffing box is arranged on the end side of the valve body corresponding to the valve plate entering the valve body direction;

the sealing cavity is opposite to the stuffing box and fixed on the end side of the valve body corresponding to the direction of the valve plate away from the valve body so as to accommodate the opened valve plate.

7. The valve of claim 4, being a dual plate spectacle valve, wherein:

the stuffing boxes comprise a first stuffing box and a second stuffing box which are symmetrically arranged at the two inlet and outlet end sides of the valve plate of the valve body, the first stuffing box is positioned at the end side of the valve body corresponding to the direction that the valve plate enters the valve body, and the second stuffing box is positioned at the end side of the valve body corresponding to the direction that the valve plate leaves the valve body;

the sealing device further comprises a sealing cavity body which is fixed on the flange pressing cover of the second stuffing box.

8. The valve according to any one of claims 5 to 7, wherein:

the device also comprises a compensator; the valve plate is fixed on the valve body and positioned on one side of the valve plate close to the valve seat, and the axis of the valve plate is parallel to the axis of the valve body; and under the condition that the pressing mechanism of the valve plate is loosened, a piston rod of an actuating mechanism of the compensator abuts against a flange b of the stuffing box.

9. The valve according to any one of claims 5 to 7, wherein:

the axial surface of the valve seat of the valve body is provided with a groove, and sealing filler is contained in the groove.

10. The valve of claim 9, wherein:

the groove is in a narrow-mouth wide-belly shape.

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