JPH0343164B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a pneumatic conveyor system, and more particularly to a line charge system having a screw conveyor and a discharge chamber for feeding solid particulate material to a pneumatic conveyor line. This invention relates to the flap valve device used. The invention also relates to a valve for closing the outlet of a screw conveyor through which the shaft of the screw vanes extends.

Prior to the present invention, it was generally known to provide pneumatic conveyor systems and line charge systems for conveying solid particulate materials, which transfer the solid particulate materials to a source such as a hopper. It includes a screw rotatably mounted within the bore of the casing for transporting from the region to the outlet of the casing. A discharge chamber or windbox is fluidly connected to the outlet of the casing for receiving particulate material. The discharge chamber is supplied with a pressurized gaseous fluid to entrain the particulate material and convey such material from the discharge chamber through a pneumatic conveyor line connected to the discharge chamber.

An early design of a pneumatic conveyor system of the type to which the present invention relates is generally known as shown in U.S. Pat. No. 1,677,119, dated July 10, 1928. This design uses front and rear bearings to rotatably support the screw blade at both ends. A compression screw formed by either a reduced pitch screw, or a reduced diameter casing bore, or an increased diameter screw wing shaft, or a combination thereof, serves to tightly pack the material within the casing bore; This forms a raw material seal within the casing between the raw material outlet of the casing and the raw material inlet of the casing. This material seal prevents "backflow" from the discharge chamber into the material feed hopper, i.e., the pressurized air used to feed the material through the line feeds the material through the pneumatic conveyor line. This serves to prevent short circuits from occurring through holes in the casing and into the material feed hopper.

Subsequent developments in pneumatic conveyor equipment of the type to which this invention relates generally occurred in October 1942.
No. 2,299,470, dated May 20th.
In this device, the front bearing supporting the screw wing of earlier designs is eliminated. The flared screw wing is supported by a rigid rear bearing. The forward end of the screw wing is held in a central position within the bore or pump barrel by employing a weighted wing shaft and by keeping the barrel full of material. In this latter device, a weighted flap valve is used to close the casing outlet. During the first start-up of the pump, the feedstock is pumped by the screw vanes from the inlet to the outlet of the pump barrel. The valve assists in forming a material seal at the outlet by remaining closed until sufficient material has accumulated to form a seal and overcome the weight closing the valve. play a role. Once the feed seal is formed, the flapper valve swings from the casing outlet to the discharge chamber and remains open as long as feed is being delivered. The raw material seal prevents "backflow".
If the flow of feed through the outlet ceases, the valve swings closed, sealing the end of the pump barrel.

U.S. Pat. No. 1,677,119 has an advantage over U.S. Pat. No. 2,299,470 in that the pump screw is supported by bearings at both ends, which prevents the pump barrel from operating at less than full capacity. This is because it allows for smooth operation. The latter patent had the advantage that the flap valve helped prevent backflow.

Attempts have been made to combine the advantages of both pumps by employing a flap valve to assist in forming a seal for the material at the outlet of the pump barrel, and by continuing to use front and rear bearings to support the pump screw. ing. Such devices are disclosed, for example, in U.S. Patent No. 5, December 1972.
No. 3704917, US Pat. No. 3704917, dated August 29, 1978.
No. 4109966, U.S. Patent No. 13, December 1983
No. 561095, French Patent No. 2 June 1972
7039326 and European Patent No. 098340 of January 4, 1983.

Some prior art techniques utilize side discharge devices, where the seal is formed perpendicular to the screwshaft. Although this device has been used successfully, many operators do not
It is preferred that the outlet of the pump screw is aligned with the pump barrel and that the outlet of the discharge chamber is aligned with the pump barrel. Previous attempts to utilize aligned outlets, such as U.S. Pat. No. 3,704,917 and European Patent No. 098,340, However, this method has disadvantages due to the wear that occurs.

In order to swing the valve freely relative to the shaft of the screw wing, European Patent No. 098340
When using a swinging valve such as that described in the above issue, it is necessary to make the opening through the valve large. This creates a large gap between the valve element and the screw shaft, causing leakage of the air being delivered and the feedstock. This annular member, as attached to the shaft, would rotate and contact the valve, causing wear. If this annular member were to be supported by some device from a stationary outer cylinder, material blockage would occur, which is undesirable and wastes energy. To overcome this, an oversized annular member is mounted on the shaft to provide a sealing point for the valve element.
It is desirable to eliminate such devices.

Other valves, such as those shown in French Patent No. 7,039,326 and US Pat. No. 1,563,826, utilize grooved valves to allow the valve element to swing on a screw shaft. This groove prevents the valve from closing the outlet of the pump barrel.

It would be desirable to provide a pneumatic conveyor system of the screw-wing type in which the screw-wings are supported by both front and rear bearings and utilize a flap valve capable of closing the outlet of an axially aligned pump cylinder. . This can be accomplished with respect to the present invention by utilizing a novel valve arrangement that is capable of sealing both with a significant sealing area around the screwshaft.

SUMMARY OF THE INVENTION The object of the present invention is to provide a pneumatic conveyor system using a novel valve arrangement which adopts the advantages of pneumatic conveyor systems of this type according to the prior art and eliminates their disadvantages.

Another object of the invention is to provide a new valve for closing the outlet of a screw conveyor through which the shaft of the screw conveyor extends.

Generally speaking, what has been described and the object is to provide a housing having an inlet at one end and an outlet at the other end, the outlet being coaxial with the housing; a screw wing having a shaft extending therethrough and a helical vane that rotates to propel feedstock from the inlet through the housing to the outlet; and a valve closing the outlet of the housing. a valve device for sealing an outlet of the housing having an opening with a diameter greater than a diameter of the shaft; and a valve element pivotally mounted for movement relative to the housing and the shaft to open the outlet. the valve element having a first portion forming a first half constituting one half of the aperture and a second portion forming a second half constituting the other half of the aperture. , wherein the first half is longitudinally spaced apart from the second half toward the entrance of the housing. This will be achieved by providing.

In connection with the present invention, a novel valve arrangement is provided for closing an outlet of a screw conveyor through which the shaft of the screw conveyor extends. The novel valve is capable of pivoting relative to the casing and shaft. The valve element is also designed to substantially seal around the screwshaft without impeding the rotational movement of the screwshaft and without the need for complex enlargements on the screwshaft. . This means that when the valve arrangement is pivoted from the closed position to the open position, the area of the valve arrangement adjacent to the pump shaft is free from the shaft until the valve element reaches a position where the material can freely flow out of the casing. This is accomplished by designing the valve elements to pivot apart. The opening through the valve element is large enough to allow the shaft to rotate freely, and small enough to provide a substantially seal around the shaft in the closed position.

The invention will now be described with reference to the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a pneumatic conveyor apparatus or line charger according to the present invention is shown for supplying solid particulate material from a source region to a pneumatic conveyor line. from which the raw material will be delivered to a remote location by pressurized gaseous fluid. The device comprises a casing, generally indicated at 1, which is formed by a hollow cylindrical part 3 having a wear-resistant liner 4. A raw material supply hopper 5 is fixed to said cylindrical part 3 by means of a suitable device, which is connected to a raw material source area (not shown). Connected to the other end of the casing 3 is a hollow part 6, which acts as a discharge chamber as will be explained later. The hopper 5 is connected to the pedestal 8, and the discharge chamber 6 is connected to the casing 3.
A pedestal 9 for supporting the device 1 and the device 1 on a foundation 10 is formed.

The casing 3 and the wear resistant liner 4 define a hole 12 extending through the casing. Said bore has an inlet 13 for feeding solid particulate material, which inlet 13 opens into the hopper 5. The casing 3 and the bore 12 also include a raw material outlet 14, which extends into the section 6 and discharges the raw material into the discharge chamber. The outlet 14 is coaxial with the hole 12.

A screw wing, generally indicated at 20, is inserted into the bore 12 of the casing 3 by a front bearing assembly, generally indicated at 21, and a rear bearing assembly, indicated generally at 22. , rotatably mounted. These bearing assemblies are known to those skilled in the art and are described in more detail in US Pat. No. 4,109,966. The wing 20 has a shaft 24 and a helical screw vane 25, which are also known in the art. The helical screw vane terminates near the outlet 14 of the wear resistant liner 4, while the shaft 24 extends through the outlet 14 and is adapted to be supported by the bearing assembly 21. .

A valve, generally indicated at 30, is used to selectively close the outlet 14 of the pumping device casing. The valve is pivoted from a closed position, as shown in FIG. 1 and in phantom in FIG. 3, to an open position, as shown in solid line in FIG. According to the prior art, this valve serves to form a feed seal at the outlet 14 of the pump body to prevent "backflow" and also to swing closed when the flow of feed through the pump is terminated. There is.

During the feeding operation, the screw blades are connected to the shaft 2.
A motor (not shown) connected to the end 23 of 4
is rotated by a suitable device, such as, to advance the feedstock from the hopper 5 and the inlet 13 through the casing hole 12. The feedstock will be tightly packed against the valve 30, forming a seal of the feedstock at the outlet 14. valve 3
When the 0 is rocked open, the raw material is discharged from the outlet 14 into the discharge chamber 6. As is known in the art, pressurized gaseous fluid is passed from a gas source (not shown) through the inlet 31 to the discharge chamber 6.
The feedstock fed into the casing and discharged from the casing outlet 14 is entrained by said pressurized gaseous fluid and is fed from the discharge chamber through an outlet such as at 33 in FIG. Fluidly connected to a conveyor line (not shown). During feeding of the raw material, the screw blades 20 continue to supply the raw material to be fed and maintain a raw material seal at the outlet 14. The feedstock flowing through the casing is reduced to the point where it is no longer possible to form a feedstock seal;
When the pressure is no longer adequate to maintain the valve element 30 in the open position, the valve 30 is rocked closed by a weight mechanism to prevent compressed gas from flowing into the casing 3. Will.
To do this, it is necessary to provide a sealable valve element to the housing of the casing and to provide a suitable seal around the shaft 24.

In the embodiments shown in FIGS. 1, 5, 7 and 8, the casing has bolts 36
It includes an extension 35 attached to the wall of the discharge chamber 6 by. This part 35 is shown in FIG.
As clearly shown in FIGS.
is cut so as to extend downward and inward toward the inlet of the casing. The valve element 30
is pivotally connected to this extension 35 at 37.

The valve element of the present invention is normally closed;
It includes a counterweight device 138 mounted on an arm 139, said arm being connected to the shaft 14.
0 to the crank arm 141, and positions the valve 30 in the closed position. In order to open the valve, sufficient pressure must be applied by the feedstock delivered to valve 30 to overcome the force of weight 138. A seal of the feedstock is thus formed at the outlet 14 in a manner known in the art.

Valve 30 surrounds shaft 24 and includes a valve element, generally indicated at 40, which seals to the housing for the screw conveyor in general and to extension 35 in particular. do. Valve 30 has an opening 41 therein;
It has a larger diameter than the diameter of the shaft 24, so that said shaft can rotate freely within the bore 12. Said opening 41 is small enough to at least partially close the outlet around the shaft 24 and to ensure that the shaft 24 and the valve element 3
It is possible to almost prevent leakage of raw materials and gas between the In terms of the functionality of the invention, the valve 30 can be swung open to its maximum extent such that the raw material can be freely discharged from the bore 12 into the discharge chamber 6 without the edges of the opening coming into contact with the shaft 24. is important. This can be achieved by making the opening larger, but such a design results in significant leakage of raw materials and gases around the shaft 24 or on the shaft 24 after the valve 30. would require a specially enlarged section.

In terms of the present invention, the valve is designed to be able to swing open so that the material can be freely discharged from the housing of the screw conveyor. This means that the edge of the aperture is in close proximity to the shaft 24 of the screw wing 20 so that the material can flow from the shaft 24 through the outlet 14 to the hole 12.
This is achieved by setting the valve to be able to swing at least until valve 30 opens sufficiently to release the liquid from the air.

The concept of driving the edges of the aperture 41 away from the widest portion of the shaft, rather than toward the shaft, allows the aperture 41 to be driven between the first half 42 forming one half and the second half forming the other half. This can be achieved by dividing the shaft 24 into two halves 43 and separating the first half from the second half along the length of the shaft 24. In the illustrated embodiment, the first half is an open bottom half 42 located longitudinally towards the casing inlet 13 from the second or top half 43 . This is because the valve is pivoted at the top; if the valve were pivoted at the bottom, its position would be reversed.

The principles of the invention are most easily visually understood with reference to FIG. In this embodiment, valve 30 is defined by a Z-shaped valve element 45 . The flap 45 includes a first portion 46 having a lower half or first half 42 of the opening 41 and a first portion 46 having a lower half or first half 42 of the opening 41
and a second portion 47 having an upper half or second half 43 of. The legs 48 and 49 are the first portion 46
and a second portion 47, separated by a length equal to the diameter of the opening 41. Second part 47
includes a housing 50 having an opening 51 for pivotally mounting valve 45 on shaft 140.

In combination with the Z-shaped flap 45 of FIG. 6, the outlet end 3 of the casing 3 of the housing
5 is stepped and includes a first portion 53 that mates with the first portion 46 of the valve element 45 and a second portion 47.
A second portion 54 is provided. The horizontal portion 55 coincides with the legs 48, 49 and therefore in the closed position said portions 46, 47, 4.
8 and 49 seal against the outlet end 35 of the casing 3 at 53, 54 and 55, respectively. According to the geometry of this design, when the valve plate 45 swings away from the outlet of the casing 3, the bottom half 42 of the opening 41
It will swing away from you. Similarly, the second or top half 43 of the aperture is also connected to the shaft 24.
It will swing away from the diameter of. The pivot point of the flap defined by the housing 50 is
It must be located before the first part of element 45.

In the embodiment shown in FIG. 5, a flat valve plate 60 is positioned above the Z-shaped flap 45. In order to support the valve plate 60, ribs 72 are added to the legs 48, 49. If a valve plate 60 is used, the end of the casing is cut so that it slopes downwardly and inwardly toward the entrance of the bore 12, as in FIG. In the embodiment of FIG. 5, the opening 41 through the valve 30 is defined by a lower half 42 and an upper half 43, similar to the embodiment of FIG. In FIG. 5, valve plate 60 is provided with an enlarged opening 64. In FIG. This opening is large enough that when the valve opens, its bottom half swings away from the shaft 24, and its top half 64a swings toward the shaft.
Edge 64a is not in the immediate vicinity of shaft 24,
No contact will occur.

Referring to FIGS. 1-4, a preferred form of valve 30 is shown. In this embodiment, the bottom leg 46 of the Z-shaped flap 45 in FIGS. 5 and 6 is eliminated, but a flat valve plate similar to that shown in FIG. 5 is used; The valve plate may be circular.
In the embodiment of FIGS. 1 to 4, valve 3
0 is a flat valve plate 70 with an oval opening 71
including. This oval opening has opening 7 in the closed position.
1 wall or edge 72 is parallel to the shaft 24 of the screw wing 20 (see FIGS. 1 and 3). The oval opening is also positioned such that the center of its lower curve is aligned with the axis 26 of the shaft 24 when the valve 30 is in the closed position (see FIG. 4).

An angle member 8 is provided on the back of the valve plate 70.
0 is attached. The angle 80 includes a first leg 81 that is generally vertical when the valve is in the closed position and a second leg 82 that is generally horizontal when the valve is in the closed position. The second legs 82 are bifurcated so that they can extend on both sides of the shaft 24. The angle member 80
has a through opening 83, which is formed by a semicircular opening in the leg 81 and a bifurcated or split leg 82.
It is formed by. This opening is in close or proximate contact with the top half of the shaft 24 when the valve is closed, and it is located in the valve plate 70.
In combination with the lower half of the aperture 71 in the valve is defined an opening 41 through the valve which surrounds the shaft 24 and at least partially seals around the shaft when the valve is closed. Therefore, the first
The valve of FIGS. 4 through 4 is similar to the valve of FIGS.
It is similar in that it forms a first portion defining a first half 42 of an opening 41 therethrough, and that it is similar to the lower plate 46 of FIG. The valve of FIGS. 1-4 has a second portion defined generally by angle member 80 and specifically by leg 81, which defines the opening through the valve. 41 and a sixth half 43;
It is similar to the top plate 47 of the valve shown. In the embodiment of FIGS. 1-4, the first portions are spaced apart longitudinally along shaft 24. In the embodiment of FIGS.
Second leg 82 of angle member 80 is similar to legs 48, 49 of FIGS. 5 and 6.

As in the case of FIGS. 5 and 6, when the valve 30 of FIGS. 1-4 swings from the closed position to the open position, the edge of the through-opening of the valve closest to the shaft will cause the raw material to flow into the casing hole. 12 will swing away from the shaft until the valve opens far enough to allow sufficient release. This is a nearly vertical position when viewed in FIG. Of course, if the valve is successively swung open, the edge will be swung closer to the shaft. For this purpose, an adjustable stopper 90 may be arranged in the discharge chamber 6.
The edges closest to the shaft 24 are the lower half 72a of the opening 71 in the valve plate 70, the upper half 83 of the angle leg 81, and the angle member 8.
The space between the legs 82 of 0.

The total diameter of all openings through the valve is shaft 2
It needs to be slightly larger than 4,
The opening is thus large enough to allow the shaft to rotate freely, and small enough to form a labyrinth-like seal around the shaft when the valve is closed. This ensures that a sufficient seal around the shaft is formed and that
Unlike No. 098340, this means that there is no need for complex sealing enlargements around the shaft 24 behind the valve 30.

Another modification of the invention is shown in FIGS. 7 and 8, in which the inlet for the gaseous fluid and the outlet for the gas and the entrained solid particulate material are coaxial with the casing. aligned with and spaced from the casing and provided with a forward discharge device.

From what has been said above, it should be clear that the objectives of the invention can be achieved.
A novel valve arrangement for a pneumatic conveyor apparatus is provided such that the valve element seals against the wall of the housing and forms a sufficient seal around the screw shaft at the outlet coaxial with the bore. be done. This will prevent backflow in the casing when feedstock is not being fed.

Valve elements 30 and 45 have been shown as a unitary structure. However, the invention also contemplates a split construction, for example, where the leg 46 is made as a separate piece bolted to the leg 48 and the leg 47 is made as a separate piece bolted to the leg 48. You should be able to understand what you are doing. Additionally, valve plate 70 can be divided into two or more sections.

Although the valve is specifically designed for use in pneumatic conveyor equipment or line chargers, it closes the outlet of all screw conveyors or all casings where the shaft extends through the outlet. It can also be used for

What has been described above is that of the preferred embodiments, and the invention is limited only by the scope of the claims appended hereto.

[Brief explanation of drawings]

1 is a sectional view of a pneumatic conveyor device according to the invention; FIG. 2 is a sectional view taken along line 2--2 of FIG. 1 in the direction of the arrow; and FIG. 3 is a sectional view of an improved valve element according to the invention Schematic diagram in open position, Figure 4 looking from the inlet end of the pump casing towards the outlet;
5 is a perspective view of a valve element according to the invention with the shaft and casing of the screw conveyor shown in phantom; FIG. 6 shows a modification of the invention; FIG. FIG. 7 is a view similar to FIG. 2 showing a modified example of the present invention; FIG. 8 is a view similar to FIG.
FIG. In the figure, 3...housing, 6...discharge chamber, 12...hole, 13...inlet, 14...
Outlet, 21, 22...bearing, 24...shaft,
30... Valve, 31... Inlet, 33... Outlet,
41...Opening, 42...First half, 43...Second
Half body, 46...first part, 47...second part, 5
3...first part, 54...second part, 55...horizontal part, 70...flat plate, 80...angle member, 81...first leg part, 82...second leg part, 83
...Enlarged aperture, 90...Stopper, 138...
It's a weight.

Claims (1)

Claims: 1. A housing having an inlet at one end and an outlet at the other end, the outlet being coaxial with the housing, a shaft extending through the outlet, and a screw wing having helical vanes that rotate to advance feedstock from the inlet through the housing to the outlet; and a valve closing the outlet of the housing, the valve having a diameter larger than the diameter of the shaft. a valve element for sealing an outlet of the housing, the valve element having an opening, and a device for pivotally mounting the valve element for movement relative to the housing and the shaft to open the outlet; a first portion forming a first half forming one half of the opening; and a second portion forming a second half forming the other half of the opening; A screw conveyor characterized in that the screw conveyor is spaced longitudinally from the two halves toward the entrance of the housing. 2. A screw conveyor according to claim 1, wherein the device for pivotally mounting the valve element is located close to the second part and remote from the first part, and the device is located close to the second part and remote from the first part, A screw conveyor, wherein the first portion is configured to move a greater arcuate distance than the second portion when pivoted to an open position. 3. A screw conveyor according to claim 1, wherein the outlet of the housing is inclined downwardly and inwardly towards its inlet, and the valve element is pivotally connected at the top. 4. The screw conveyor according to claim 3, wherein the first portion of the valve element forms a bottom half of the opening, and the second portion forms a top half of the opening. and the first part has a flat plate sealing the housing, and the second part has an angle member mounted on the flat plate, and the angle member is substantially in contact with the valve when the valve is closed. A screw conveyor having a first leg that is vertical and forms the top half of the opening, and a second leg that is substantially horizontal when the valve is closed. 5. The screw conveyor according to claim 4, wherein the second leg portion is bifurcated and extends on both sides of the shaft in the diametrical direction. 6. A screw conveyor according to claim 2, wherein the outlet of the housing is stepped and includes a first section spaced longitudinally from a second section; a horizontal portion connecting a second portion, the first portion of the valve element sealing a first portion of the outlet of its housing, and the second portion of the valve element sealing a second portion of the outlet of the housing. A rustic screw conveyor.