JPH0126433B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates generally to piping transportation systems and more particularly to valve housings.

The valve housing of the present invention can be applied to slurry transfer in piping by liquid or gas streams.

This valve housing can also be used for the transport of liquids, gaseous materials, soft abrasive materials such as suspensions, and other materials.

Valve housings are already known which consist of a coaxial arrangement of end tubes for connection with piping in order to form a straight flow path for a fluid carrying abrasive solids to be transported. It is being (SF USSR Inventor's Certificate No. 479925) A gate for closing the straight flow passage is arranged in the upper part of the valve housing so as to move in a vertical plane. The lower portion of the interior of the valve housing includes a plurality of continuous asperities disposed along the length of the straight flow passage. Each protrusion or rib extends substantially across the rectilinear flow path in an arc of not less than 120 degrees.

Each protrusion or rib is shaped like a trapezoid in a cross section through the longitudinal centerline of the rectilinear flow passage. The ribs are made from the same material as the valve housing and end tube. The ribs are intended to facilitate the formation of a layer of solid particles on the lower part of the inner wall of the valve housing. These solid particles tend to settle down between the ribs and become stable, and are stacked one after another.

The presence of a submerged layer of solids protects the lower portion of the inner wall of the valve housing from being abraded by particulates carried by the transported fluid. To reduce flow resistance and prevent pressure loss within the valve housing, the depth of the submerged particulate layer is
It is preferable to make it as small as possible. However, if the depth is too shallow, large solid particles carried by the fluid flow will easily penetrate into the layer of submerged solids.

Furthermore, the ribs of the valve housing are made of the same material as the housing and the end tubes and are therefore susceptible to premature wear due to larger particles having an abrasive action penetrating the layer of smaller settled particles. . As a result of the rapid wear of the ribs, the life of the valve housing and end tube is very short.

The shape of the ribs in the cross section through the straight flow passage of the above known valve housing provides a layer of solid particles between the ribs, which is sufficiently stable, especially at increased flow rates under certain operating conditions. It cannot be said that it is a certain thing. There, the depth of the solid matter subsidence layer is
It tends to be substantially lower than the height of the ribs, which results in faster wear of the lower portion of the wall of the valve housing.

The invention thus provides a valve housing in which the ribs of the lower inner wall portion reliably form a stable layer of solid matter in a cross section passing through the longitudinal centerline of the straight flow passage in the valve housing. It is an object.

It has an end tube that mates with the piping to form a straight flow path for the fluid flow to be transferred, and a lower portion of the inside wall of the flow path having a plurality of ribs, each rib having a , extending substantially transversely to the straight flow passage, and according to the invention, each rib is serrated in cross-section through the longitudinal centerline of the straight flow passage. The thickened part of the rib faces the inlet of the fluid to be transported.

Because of the cross-sectional shape of the ribs, the thickened portion of each rib facing the fluid inlet ensures that the settling of solids onto the lower portion of the inner wall of the valve housing in front of this thickened portion of the rib. promotes the formation of a stable layer of solids. The depth of this layer remains unchanged during long-term use of the valve housing.

There, in fact, larger solid particles carried by the flow cannot penetrate this layer. On the other hand, the layer itself serves to protect the ribs and the lower inner wall of the valve housing from abrasion and abrasion.

The rib having the above cross-sectional shape may be formed by surface hardening the lower portion of the inner wall of the housing, or may be made of a material different from the material of the valve housing.

Preferably the ribs are made from a wear resistant material.

This wear resistant material increases the life of the ribs and the durability of the valve housing.

Preferably, the surface of each rib facing the inlet of the fluid to be transported is at an angle with a plane transverse to the straight flow path. The value of this angle should not exceed the value of the friction angle of the solid particles carried by the fluid against the ribs.

By providing each rib with such an angle, the layer of solids sinking into the lower inner wall of the passage can be made very stable. The depth of such a layer is therefore stable even at high velocities of fluid flow.

Preferably, the height of each rib is in the range of 0.03 to 0.05 of the maximum cross-sectional diameter of the straight flow passage.

If the ratio of the height of each rib to the maximum cross-sectional size of the straight flow passageway, or the diameter of such passageway when it is substantially circular, is less than 0.03, the layer of solids completely covers the ribs. They are not deep enough to cover them and will cause them to wear out quickly.

Conversely, if the above ratio exceeds 0.05, the depth of the solid material layer becomes very large, but this results in a decrease in the cross-sectional area of the straight flow passage, increasing fluid resistance and pressure loss in the valve housing. It will affect its efficiency.

In view of the foregoing, the valve housing of the present invention has a long service life. Furthermore, it is very efficient and is achieved without any pressure loss of the transported fluid. On the other hand, expensive wear-resistant materials are only used in small amounts on the ribs and not on the entire valve housing.

Referring to FIG. 1, a valve housing embodying the invention is shown here with a straight flow passage 3 for a valve or a fluid to be transferred, such as a slurry.
including end tubes for coupling to piping (not shown) defining the housing, which are disposed coaxially on opposite sides of the housing. The end tube 2 can be connected to a pipe by means of a flange 4. In the example,
The end tube 2 is made in one piece with the housing 1. The end tubes may be joined by any other known suitable means, such as screw connections, welding, soldering, etc.

In another alternative variant, the end tube 2 would also be firmly fixed to the valve housing 1.

The end tube is arranged to coincide with the longitudinal centerline 5 of the valve housing 1. Furthermore, a branch pipe 7 is provided in the upper part of the valve housing 1 with an axis 6 perpendicular to the longitudinal centerline 5. The branch pipe 7 is such that a valve member 8 can be attached to a valve seat 9 within the valve housing 1 . A groove or inner shoulder (not indicated by a reference number) is provided in the inner wall of the housing 1 for receiving a valve seat 9 which can be mounted within the housing 1 by any suitable means known in the art.

The valve member 8 is disposed so as to coincide with the vertical axis 6 and engages with the valve seat 9 by means of an annular convex portion provided around the periphery of the valve member on the side facing the valve seat 9. The side of the valve member opposite to the above-mentioned side is, in the upper part of the valve member, a generally flat surface 11 perpendicular to the longitudinal centerline 5 of the valve housing, while the valve member 8 on this side is In its lower part it is a flat surface 12 which is inclined with respect to the horizontal center line 5.
In the lower part of the valve member 8, the cross-sectional area taken parallel to the horizontal longitudinal centerline 5 and substantially parallel to the vertical axis 6 is greater than the cross-sectional area taken in a similar manner in the upper part of the valve member 8. small. That is, it increases gradually from the lowest end of the valve member 8 up along the vertical axis 6, as seen in FIG.

In order to perform the reciprocating motion, the valve member 8
It is coupled to drive means (not shown) of known and suitable construction. This connection to the drive means is connected to the first
This is done via a rod 13, shown at 14 in the figure, which is attached by any known suitable screw connection. A recess 15 is provided in the lower part of the valve housing extending up to the longitudinal centerline 5, assuming that it assumes its lowermost position when the valve member closes or obstructs the straight flow passage 3. , making it easier to operate the valve member.

The cylindrical recess 15 extends through a tapered joint 16 to the right-hand end tube 2 . The valve member is placed at a fixed distance from the lower wall of the cylindrical recess 15 in its lowermost position. The solid particle layer of slurry that has accumulated at the bottom of the channel 3 is thereby transferred to the correct direction of the end tube 2, allowing the member 8 to block the channel 3 completely.

A plurality of ribs 17 are arranged in the lower part of the passage 3.

Each rib 17 extends along the cross-section of the passageway 3 in an arc of not less than 120 DEG, which in this embodiment best shown in FIG. 1 is exactly 120 DEG.

Referring now to FIG. 2, the rib 17 is located directly on the lower part of the wall of the passage 3 of the end tube 2.

In another embodiment of the invention shown in FIG. 3, the ribs 17 are arranged in recesses 17a made in the lower part of the wall of the passageway 3.

Such an arrangement of the ribs 17 within the recess 17a is
The fluid resistance of the valve housing 1 will be felt.

Each rib 17 is serrated in a cross section through the longitudinal centerline of the passageway 3, as best shown in FIG. The thicker part of each rib 17 faces the inflow of the fluid carried through the passageway 3, the direction of this flow being indicated by B in FIG.

The previously described shape of the ribs 17 facilitates the settling of the grains in front of their thickened parts.

The ribs 17 are made of a hard-faced wear-resistant material on the inner wall of the passageway 3. This anti-wear material extends the life of the valve housing, while the surface hardening
Saves the amount of expensive material required for rib formation.

Referring to FIG. 4, the surface 18 of each rib facing the fluid inlet is sloped at an angle .alpha. with a surface 19 across the passageway 3. The conveyed fluid is in this case a slurry or a mixture of water and solid mineral particles. The angle α is selected to be less than or equal to the friction angle of the solid mineral grains carried by the fluid on the ribs 17. Experiments have shown that at this value of angle α, rib 17
It has been found that the depth of the layer of intervening solids does not decrease even when the velocity at which the fluid is carried increases, and this protects the lower part of the passage 3 from abrasion and abrasion.

Each rib 17 has a height h that is 0.04 of the passage diameter. At such values of the height h of the ribs 17, the layer of stuck particles prevents the lower part of the channel 3 from premature wear and provides a sufficient service life. This height of the ribs 17 also prevents increased resistance to fluid entering the valve housing and pressure losses therein.

The valve housing of the present invention operates in the following manner.

When the valve member 8 is moved upwards, the mouth of the valve seat 9 opens so that the fluid flow moves in the direction indicated by B, and the fluid flows from the piping to the right end tube 2 as shown in FIG. It then flows out of the valve housing 1 through the open valve seat 9. This flow carries abrasive solids due to the known fact that the hydrodynamic lifting force created by the transported fluid stream exceeds the gravity of each solid particle. . Since the fluid flow velocity near the ribs 17 is less than the flow velocity near the longitudinal centerline, this lifting force is overcome by the gravity of the solid particles. Therefore, each solid particle tends to sink and is carried away by the longitudinal flow of the passage 3. There, the path of the solid particles is curved, as indicated by C in FIG. Upon impacting the surface 18 of the rib 17 facing the flow, each solid particle exerts a force designated D on the surface 18. Power D
The components of are a force E normal to the surface 18 and a force F tangential. The angle of incidence on the surface 18 of the solid particle (the angle between the normal to the surface 18 and the incident vector of the solid particle) is an angle only when the gravity of the solid particle is zero and it moves in the direction B of the fluid flow. equal to α and less than angle α when gravity is not zero. Since the angle between force D and force E is α when the gravity is zero, the tangential force F is equal to or smaller than E multiplied by the tangent α. The force F acts to push the solid grain upwards, but this action is counteracted by the frictional force G of the solid grain against the surface 18 of the rib 17. As is well known, the force of friction is equal to the product of the force perpendicular to the friction surface and the tangent of the angle of friction. In this case, the force directed perpendicular to the friction surface 18 is E, so the force G is the force E multiplied by the tangent of the friction angle. The force G is always greater than the force F, since the value of the angle α is chosen to be substantially smaller than the friction angle of the solid particles against the ribs 17. Therefore, the solid grains do not move upward and the rib 17
during which it settles and remains there even as the velocity of fluid flow increases. As a result, a stable layer of submerged solid particles is formed, which serves to protect the lower portion of the inner wall of the valve housing from abrasion and abrasion.

At a height of the ribs 17 of 0.04 of the cross-sectional diameter of the passageway 3, the layer of submerged solids allows the lower part of the internal wall of the valve housing 1 to flow freely without substantially any increase in the fluid resistance of the valve housing 1. It is well protected against being abraded by such solids carried by the flow.

Valve housings embodying the invention have shown excellent results when tested against soft abrasive piping transport in the coal industry.
The life of such a valve housing was several times that of known valve housing constructions used for the same purpose, and without a substantial increase in the fluid resistance of the transported fluid flow. Further, the rib having the shape of the present invention does not require any additional processing, has a low manufacturing cost, and is suitable for mass production.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a valve housing of the present invention. FIG. 2 is a sectional view taken along the line - in FIG. 1. FIG. 3 is a sectional view of another embodiment of the valve housing of the present invention, in which the lower portion of the straight flow passage has a recess with internal ribs. FIG. 4 is an enlarged view of section A in FIG. 1. DESCRIPTION OF SYMBOLS 1... Housing, 2... End tube, 3... Passage, 4... Flange, 5... Longitudinal center line, 6
...Axle perpendicular to center line 5, 7...Vertical branch pipe,
8... Valve member, 9... Valve seat, 10...
... Annular convex portion, 11 ... Flat surface, 12 ... Inclined flat surface, 13 ... Rod, 14 ... Threaded joint, 15 ... Cylindrical recess, 16 ... Joint part, 1
7... Rib, 18... Rib surface facing the fluid flow to be transported, 19... Surface crossing the passage, B... Direction of fluid flow, C... Passage of solid particles, D... Solid particle Impact force on the rib surface, E... Force perpendicular to the surface, F
... tangential force, G ... gravity, α ... angle between the surface of the rib facing the transported fluid stream and the surface across the passage.

Claims (1)

Claims: 1. An end tube 2 that joins the pipe to form a straight flow passage 3 for the fluid flow to be transported; a lower part of the inner wall of the straight flow passage having a plurality of ribs 17; and each rib 17 extends substantially transversely to the straight flow passage 3. In the valve housing, each rib 17 has a serrated shape in a cross section through the longitudinal centerline 5 of the straight flow passage 3. A valve housing characterized in that the thickened portion of the rib 17 faces the inflow of fluid. 2. The valve housing according to claim 1, wherein the ribs 17 are made of a wear-resistant material. 3 In the valve housing described in claim 1, the rib 17 facing the fluid inflow
is characterized in that its surface forms an angle α with respect to a plane across the straight flow path 3, and the value of this angle α does not exceed the value of the friction angle of the solid particles carried by the fluid flow on the ribs 17. valve housing. 4. In the valve housing described in claim 1, the height h of each rib 17 is
A valve housing characterized in that the maximum cross-sectional diameter of the straight flow passage 3 is in the range of 0.03 to 0.05.