GB2142121A - Gate valve - Google Patents

Abstract

A gate valve comprises a housing (1) having butt pipes (6) to form with a pipeline a straight-flow passage (8), and a gate (10) having a hole (11) therein, the gate (10) being adapted to come into engagement with one of the butt pipes (6) to close the straight-flow passage (8). The gate 10 is connected by its ends (16) to the ends (17) of rods (13) movable by a drive means (14). The gate (10) and each of the rods (13) have equal areas taken in a cross-section perpendicular to the longitudinal axis (2) of the rods (13). The ends (16) of the gate (10) and the ends (17) of the rods (13) connected to the gate ends (16) have shaped end faces (18,19) disposed in opposition to each other and serving to facilitate the passage inside the housing (1) of the gate and rods through solid particles accumulated from the fluid being conveyed. <IMAGE>

Description

SPECIFICATION Gate valve This invention relates generally to equipment for hydraulic and pneumatic pipe transport systems, and more particularly to a gate valve.

A gate valve emobodying the present invention can find application in pipelines intended to convey loose materials containing high amounts of solid abrasive particles, especially to transport slurries in pipes.

The device according to the invention can also be used for transporting various materials in the mining, construction, chemical and other industries by pipe-transporting fluid suspensions of solid particles.

The invention provides a gate valve comprising a housing having butt pipes for connection to a pipeline to form therewith a straight-flow passage and a gate having a hole therein for a fluid containing suspended solid particles to pass therethrough, the gate being adapted to come into contact with at least one of the butt pipes for blocking this butt pipe and connected by its ends furthest from a longitudinal centerline of the butt pipes to ends of rods of drive means for imparting reciprocating motion to the gate to thereby open and close the straight-flow passage, the rods being disposed inside the housing for part of their length on opposite sides of the longitudinal centerline of the butt pipes, the gate and each of the rods having equal areas taken in cross-sections perpendicular to a longitudinal axis of the rods, the ends of the gate and the ends of the rods having shaped end faces arranged in opposition to each other and adapted to facilitate the passage inside the housing of solid particles contained in the fluid being conveyed in the course of reciprocating motions of the gate, these particles tending in use to pass from a volume partially occupied by the gate to a volume being relieved by the adjacent rod, and from a volume occupied by the other of the two rods to a volume being relieved by a portion of the gate adjacent thereto.

By virtue of the foregoing arrangement the gate is capable of easy displacements throughout extended operating life of the gate valve whilst conveying fluids containing high amounts of solids, even when such solids occupy the entire interior of the gate valve housing.

Preferably, the connection of the ends of the gate to respective ends of the rods is effected by means of a lug provided at each end of the gate and a fork provided at the corresponding ends of each rod, the shaped end face of each end of the gate having a portion adjacent to a side surface of the gate to form therewith an acute angle in a longitudinal section taken transversely of the direction of the fluid flow, and portion between the lugs and the above firstmentioned portion of the shaped end face of the gate having in a longitudinal section taken in line with the direction fo the fluid flow the shape of a wedge with an apex thereof facing the longitudinal centerline of the straight-flow passage, the shaped end face of the end of each rod defining a side surface of each jaw of the fork making with a generatrix of the side surface of the rod in a longitudinal section passing in line with the direction of the fluid flow an acute angle, lines tangent to the shaped end face of the end of each rod making therebetween an acute angle in a longitudinal section taken transversely of the direction of the fluid flow.

The above arrangement of the end faces of the gate and the rod ends connected to the gate provide for free movement of solid particles settled inside the housing during reciprocating motions of the gate from a volume partially occupied by the gate to a volume relieved by the adjacent rod. Simultaneously, the solids settled in the housing tend to pass from a volume occupied by the other rod to a volume relieved by a portion of the gate adjacent to this rod.

A gate valve embodying the present invention provides reliable closing and opening of a pipeline and offers long service life when operated with fluids containing high amounts of abrasive solids.

These and other advantages of the invention are disclosed in greater detail in a description of preferred embodiments thereof that follows taken in conjunction with the accompanying drawings in which: Figure 1 is a longitudinal sectional view of a gate valve embodying the present invention; Figure2 is an enlarged view of section A in Figure 1; Figure 3 is an enlarged view taken along the arrow B in Figure 2; Figure 4 is a section taken along the line IV-IV in Figure 3; Figure 5 is a schematic axonometric illustration by solid lines of ends of gate rods for connection to ends of a gate member, dash-dot lines showing the upper end of the gate member;; Figure Shows schematically by solid lines the gate member and the rods in their initial position, the dash-dot lines showing the gate member and the rods in an intermediate position during their downward movement.

The gate valve embodying the present invention is intended predominantly for use in slurry pipe transportation.

With reference to Figure 1, the gate valve comprises a housing 1 of cylindrical shape having a vertical longitudinal axis 2. The housing 1 is enclosed at the upper and lower ends by lids 3 of hemispherical shape attached to flanges 4 of the housing 1 by their mating flanges 5.

The housing 1 has butt pipes 6 made integral therewith and serving for connection to a pipeline (not shown) by its flanges 7 to form with the pipeline a straight-flow passage 8 for a fluid to be conveyed therethrough in a direction indicated by the arrow C.

A longitudinal centerline 9 of the passage 8 is substantially perpendicular to the vertical longitudinal axis 2 of the housing 1 and is also the longitudinal centerline of the two butt pipes 6.

The butt pipes 6 extend inside the housing 1 for part of their length.

Accommodated inside the housing 1 between the butt pipes 6 in line with the vertical longitudinal axis 2 of the housing 1 is a gate 10.

The gate 10 has a hole 11 for the passage of a fluid, such as a liquid carrying suspended solid particles therethrough.

When the straig ht-flow passage 8 is closed, the gate 10 firmly contacts by its face 12 the left-hand butt pipe 6 as best seen in Figure 1 and therefore closes this butt pipe 6. The gate 10 is spaced a certain distance from the right-hand butt pipe 6.

Disposed also for a part of their length inside the housing 1 are rods 13 arranged in line with the vertical longitudinal 9 of the butt pipes 6. The rods 13 are kinematically linked with a drive means 14 providing for reciprocations of the gate 10 to effect closing and opening of the straight-flow passage 8.

Alternatively, each rod 13 may have a separate drive means.

The drive means 14 of any known suitable design not to be described hereinafter. The rods 13 are adapted to extend to the interior of the housing 1 through bores (not indicated by reference numerals) in the lids 3 in line with the vertical axis 2 of the housing 1. The rods 13 are packed against leaks relative the lids 3 by sealing rings 15. Opposite ends 16 of the gate 10 are connected to adjacent ends 17 ofthe rods 13; the connection between the ends 16 and 17 will be described later in the description.

The gate 10 and each of the rods 13 have equal cross-sectional areas taken perpendicularly to the vertical axis 2, each rod 13 being essentially round and the gate 10 being rectangular in cross-section.

The ends 16 ofthe gate 10 haveshaped end faces 18, while the ends 17 of the rods 13 have shaped end faces 19. The shaped end faces 18 and 19 oppose each other and are arranged such that solid particles of the fluid being conveyed are capable of free passage inside the housing 1 in the course of reciprocations of the gate 10 from a volume partially occupied thereby to a volume released by the adjacent rod 13, as well as from a volume occupied by the other rod 13 to a volume relieved by the adjacent portion of the gate 10. As has been mentioned earlier, the gate 10 and each of the two rods 13 have equal cross-sectional areas. Thanks to the aforedescribed, complete passage of all solid particles carried by the fluid is facilitated between the two said volumes, which in turn aids in the movement of the gate 10.

Connection of the ends 16 of the gate 10 to the corresponding ends 17 of the rods 13 is effected by means of a lug 20 provided at each end 16 of the gate 10 and a fork 21 provided at the respective ends 17 of each rod 13.

The lug 20 of each end 16 of the gate 10 has a hole 22 the axis of which is parallel with the longitudinal centerline 9.

The fork 21 has two jaws 23 in which there are provided two drillings 24 (Figure 2). Axes of the drillings 24 are close to coinciding with the axis of the hole 22 when the ends 16 of the gate 10 are connected to the ends 17 of the rods 13. Said ends 16 and 17 are interconnected by means of a pin 25 having a head 26 at one end and a clip ring 27 at the other end thereof.

A certain amount of setting clearance (not indicated by a reference character) is allowed between the pin 25 and the walls of the hole 22 of the gate 10.

The jaws 23 of the fork 21 are parallel with the axis 2.

Outer surfaces 28 of the jaws 23 are cylindrical and integral with the outer surface of each rod 13, whereas inner surfaces 29 of the jaws 23 which face the ends 16 of the gate 10 are planar.

Clearances (not indicated by reference characters) are provided between each end 16 of the gate 10 and the inner surfaces 29 of the jaws 23, as well as between each end 16 of the gate 10 and a surface 30 connecting the inner surfaces 29 of the jaws 23.

With reference to Figure 3, the shaped end face 18 of each end 16 of the gate 10 has a portion 31 adjacent to a side surface 32 of the gate 10.

The portion 31 defines with the side surface 32 an acute angle a if viewed in a longitudinal section parallel with the surface 12 of the gate 10.

This makes it possible for the solids occupying the interior of the housing to travel along the portion 31 of the end face 18 during displacement of the gate 10, which will be elaborated on when operation of the gate valve is described.

The end face 18 of each end 16 of the gate 10 also has portions 33 interposed between the lug 20 and the portion 31.

In a longitudinal section perpendicularto the face 12 of the gate 10 these portions 33 are wedgeshaped as seen best in Figure 4, their apices 34 facing the adjacent rod 13.

The heretofore described arrangement of the end face 18 of each end 16 ofthe gate 10 providesfor a free passage of solids during displacements of the gate 10.

Referring now to Figure 5, the shaped faces 19 of the end 17 of each rod 13 define side surfaces of the jaws 23 of the fork 21.

The shaped end face 19 of each end 17 of the rod 13 defining the side surfaces of each jaw 23 makes with the generating line of the side surface of the rod 13 an acute angle p if viewed in a longitudinal section taken perpendicularly to the face 12 of the gate 10.

Therewith, lines tangent to this shaped end face make an acute angle w if viewed in a longitudinal section parallel with the face 12 of the gate 10.

Such an arrangement of the jaws 23 of the fork 21 serves to further facilitate the free travel of solids inside the housing 1.

The gate valve embodying the present invention operates as follows.

Upon engagement of the drive means 14 the rods 13 kinematically linked therewith initiate their reciprocating motion along the vertical axis 2.

The lower rod 13 imparts movement to the gate 10 via the pin 25 tightly fitted in holes 24 of the jaws 23 of the fork 21 and received loosely in the hole 22 of the lug 20 whereby the gate 10 is caused to move along the vertical axis 2.

While being displaced along the vertical axis 2 the gate 10 also imparts movement to the upper rod 13 (Figure 1), this movement being transmitted through the pin 25 engageable with the fork 21 of the upper rod 13 and the upper lug 20 of the gate 10.

Upon the movement of the rods 13 the face 12 of the gate 10 displaces relative to the left-hand butt pipe 6 (Figure 1).

Thereafter, the hole 11 of the gate 10 is put in registration with the direct-flow passage 8 to ensure complete opening of the passage 8 when the axis of the hole 11 is in complete alignment with the longitudinal centerline 9 of the passage 8.

Concurrently, the end face 18 of the lower end 16 of the gate 10 and the end face 19 of the end 17 of the rod 13 are drawn nearer to the lower lid 3 (Figure 1) of the housing 1, whereas the respective end faces 18 and 19 of the upper end 16 of the gate 10andthe end 17 of the upper rod 13 move away from the upper lid 3 of the housing 1.

Referring now to Figure 6, the gate 10 and the rods 13 assume a position shown in this Figure by solid lines prior to executing the movements described heretofore.

After executing a downward movement at a distance indicated by D (Figure 6), the gate 10 and the rods 13 assume a position shown in Figure 6 by dash-dot lines.

Therewith, the lower rod 13 will release a volume equal to a product of the cross-sectional area of the lower rod 13 and the distance D of displacement.

To ensure a free movement of the gate 10, it is necessary that solid particles be removed from under the lower end 16 of the gate 10, these solid particles occupying a volume equal to a product of the cross-sectional area of the gate 10 and the distance D of diplacement.

Because the cross-sectional areas of the gate 10 and each of the rods 13 are equal, the above volume occupied by the solid particles is likewise equal to the volume relieved by the rod 13.

Therefore, the movement of the lower rod 13 ensures the provision of a volume for the solid particles which is equal to the volume occupied by the gate 10 during its downward movement.

In a likewise manner a volume is provided near the upper end 16 of the gate 10 which is equal to the volume occupied by the upper rod 13 during its downward movement.

The en'd surfaces 18 of the gate 10 have areas common with the end surfaces 19 of the rods 13, these areas being confined by points 35,36, 37 and 38.

A volume relieved by the rod 13 during its downward movement is occupied by the body of the gate 10.

To ensure unobtrusive movement of lye gate 10 downwards solid particles occupying volumes confined by points 35,36,35', 36', 39,40,39', 40' and points 37,38,37', 38,41,42,41', 42' are caused to pass into volumes relieved by the lower rod 13 as shown in Figure 6 by points 35,38,43,35', 38', 43' and 36,37,44,36',37',44'.

The shaped configuration of the end face 18 of each end 16 of the gate 10 provides for the passage of solid particles from under the end face 18 of the lower end 16 of the gate 10 to the volumes relieved by the lower rod 13 in directions indicated by the arrows E, F, G and H.

For the sake of clarifying the abovementioned passage of the solids, the arrow E shows the path of travel of such solids from the volume of a prism having a base area indicated by S1 and height D to an equal volume of a cylinder having a height D and base area indicated by S2 which is substantially the same as the area S1,thetwo base portions having areas S, and S2 being hatched.

The aforedescribed takes place due to the fact that during lowering of the end face 19 of the end 17 of the upper rod 13 into a bed of settled solids the latter tend to travel along portions 31 thanks to the acute angle a between a side surface 32 (Figure 3) of the gate 10 and the portion 31 toward the longitudinal vertical axis 2 to thereby get closer to the volume relieved by the lower rod 13.

Along the path of their travel the solid particles run against the intermediate portions 33 having in a longitudinal section the shape of a wedge with an apex at 34.

The apex 34 separates the solid particles into two equal flows which are directed by the portions 33 toward the volumes having the base area indicated by S2 in Figure 6.

In this manner the solid particles pass inside the housing 1 to occupy the volumes relieved by the lower rod 13 from under the end face 18 of the lower end 16 of the gate 10, which facilitates the unobtrusive movement of the gate 10 downwards.

During the downward movement of the gate 10 the end face 18 of its upper end 16 and the end face 19 of the end 17 of the upper rod 13 pass through the distance D from the position shown in Figure 6 by a solid line to the position indicated by a dash-dot line.

Due to the equality of the cross-sectional areas of each rods 13 and the gate 10 the volume relieved by the gate 10 is equal to the volume occupied by the solid particles under the end face 19 of the end 17 of the upper rod 13.

From under the end face 19 of the end 17 of the upper rod 13 the solid particles tend to follow paths indicated in Figure 6 by the arrows J, K, Land M.

This movement of the solids occurs by virtue of the fact that the shaped end face 19 of the end 17 of the upper rod 13 defining the side surface of each jaw 23 of the fork 21 makes relative to the generatrix of the side surface of the rod 13 the acute angl p in a longitudinal section of the rod 13 passing in line with the direction of the fluid flow indicated by C, whereas the lines tangent to the shaped end face 19 of the end 17 of each rod 13 make therebetween the angle y (Figure 5) in a longitudinal section transverse to the flow direction indicated by C.

Thanks to the inclination of the side surfaces of the shaped end face 19 of each jaw 23 of the fork 21 at the angle p, the solids tend to pass from the periphery of the rod 13 in a direction toward the vertical longitudinal axis 2.

The inclination of the lines tangent to said surfaces to define therebetween the angle y in a longitudinal section transverse to the flow direction indicated by Cfacilitatesthe passage of solids toward the side surfaces 32 of the gate 10.

Concurrently, the provision of the angles p and z ensures the passage of solids in the direction indicated by the arrows J, K, Land M from under the shaped end face 19 of the end 17 of the upper rod 13 (Figure 6), the solids thus passing from the volumes having the base areas indicated by S2 to the volumes having the base areas S,=S2 relieved in the course of the downward movement of the gate 10. The passage of solids from under the shaped end face 19 of the end 17 of the upper rod 13 (Figure 6) to the volumes relieved by the gate 10 facilitates easy movement of the upper rod 13.

The movement of solids from under the shaped end face 18 of the lower end 16 of the gate 10 to the volume relieved by the lower rod 13 and simultaneous travel of solids from under the shaped end face 19 of the end 17 of the upper rod 13 (Figure 6) to the volume being relieved by the gate 10 promotes easy opening of the straight-flow passage 8.

When the rods 13 and the gate 10 are moved upwards, the face 12 of the gate 10 comes into contact with the left-hand butt pipe 6 (Figure 1) to be pressed thereagainst by the flow of fluid being conveyed in the direction indicated by C.

The provision of clearances between the holes 22 in the lugs 20 and the pins 25, as well as the spacings between each end 16 of the gate 10 and the inner surfaces 29 of the jaws 23 and the inner surface 30 between these inner surfaces 29 enable the face 12 of the gate 10 to tightly fit against the end face of the left-hand butt pipe 6 as best seen in Figure 6, which ensures hermetic blocking of the straight-flow passage 8.

During the upward movement of the gate 10 and the rods 13 solids travelling along their end faces 18 and 19 tend to pass to the volumes being relieved.

Therewith, solid particles passing through the shaped end face 18 ofthe upperend 16 ofthegate 10 move to the volume being relieved by the upper rod 13, while from under the shaped end face 19 of the end 17 of the lower rod 13 (Figure 1) the solid particles are forced into the volume relieved by the gate 10, the solids being moved in a manner similar to what has been described with reference to the downward movement of the gate 10 and the rods 13.

The aforedescribed provides for a reliable movement of the gate even when the housing 1 of the gate valve is filled with a large amount of solid particles.

A pilot model of the gate valve embodying the present invention has been manufactured and successfully passed tests when operated with coal slurries containing high concentrations of solid particles.

In view of the foregoing, the proposed gate valve provides reliable opening and closing of slurry pipes.

Claims (3)

1. A gate valve comprising a housing having butt pipes intended for connection to a pipeline to form therewith a straight-flow passage and a gate having a hole therein for a fluid containing suspended solid particles to passtherethrough; said gate being adapted to come into contact with at least one of said butt pipes for blocking this butt pipe and connected by its ends furthest from a longitudinal centerline of said butt pipes to ends of rods of drive means for imparting reciprocating motion to said gate to thereby open and close said straight-flow passage; said rods being disposed inside said housing for part of their length on opposite sides of the longitudinal centerline of said butt pipes; said gate and each of said rods having equal areas taken in cross-sections perpendicular to a longitudinal axis of said rods, said ends of said gate and said ends of said rods having shaped end faces arranged in opposition to each other and adapted to facilitate the passage inside said housing of solid particles contained in the fluid being conveyed in the course of the reciprocating motions of said gate, these particles tending in use to pass from a volume partially occupied by said gate to a volume relieved by the adjacent of said rods, and from a volume occupied by the other of said two rods to a volume relieved by a portion of said gate adjacent thereto.

2. A gate valve according to claim 1, wherein the connection of said ends of said gate to respective ends of said rods is effected by means of lugs provided at each of said ends of said gate and a fork provided at the corresponding ends of each of said rods; the shaped end face of each end of said gate having a portion adjacent to a side surface of said gate to form therewith an acute angle if viewed in a longitudinal section taken transversely of the direction of the fluid flow, and portions between the lug and said portion having in a longitudinal section taken in line with the direction of the fluid flow the shape of a wedge with an apex facing the longitudinal centerline of said straight-flow passage; the shaped end face of the end of each said rod defining a side surface of each jaw of said fork making with a generatrix of the side surface of said rod in a longitudinal section passing in line with the direction of the fluid flow an acute angle, whereas lines tangent to the shaped end face of said end of each said rod making therebetween an acute angle in a longitudinal section taken tranversely of the direction of the fluid flow.

3. A gate valve substantially as hereinbefore described with reference to and as shown in the accompanying drawings.