US3735641A

US3735641A - Diverting and sampling gate

Info

Publication number: US3735641A
Application number: US00077985A
Authority: US
Inventors: W Bink; G Dempster
Original assignee: Sherritt Gordon Mines Ltd
Current assignee: Viridian Inc Canada
Priority date: 1970-10-05
Filing date: 1970-10-05
Publication date: 1973-05-29
Anticipated expiration: 1990-05-29

Abstract

A gate for diverting and/or sampling the entire flow of particulate material in an upright chute. The gate includes a gate means positioned to extend slidably from an inoperative position in which the gate means spans substantially none of the cross-sectional area of the upright chute means through an opening in a wall of the upright chute to an operative position in which the gate means spans the entire cross-sectional area of the upright chute. Not only is the chute easily constructed and operated, it permits taking a sample with greater confidence in the qualititative and quantitative analysis of the sample.

Description

llited tates Patent 1 Pink et a1.

[451 May 29, 1973 DIVERTING AND SAMPLING GATE Inventors: Werner R. Bink, Fort Saskatchewan, Alberta; George Dempster, Edmonton, Alberta, both of Canada Assignee: Sherritt Gordon Mines Limited,

Toronto, Ontario, Canada Filed: Oct. 5, 1970 Appl. No.: 77,985

References Cited I UNITED STATES PATENTS 2,550,240 4/1951 Geiger et a1 143/31 R X 3,253,470 5/1966 Platzer et al ..73/423 X 1,521,545 12/1924 Kistler ..73/423 S 7] ABSTRACT A gate for diverting and/or sampling the entire flow of particulate material in an upright chute. The gate includes a gate means positioned to extend slidably from an inoperative position in which the gate means spans substantially none of the cross-sectional area of the upright chute means through an opening in a wall of the upright chute to an operative position in which the gate means spans the entire cross-sectional area of the upright chute. Not only is the chute easily constructed and operated, it permits taking a sample with greater confidence in the qualititative and quantitative analysis of the sample.

5 Claims, 3 Drawing Figures PATENIEU NW2 9 I973 Agent 1 DIVERTING AND SAMPLING GATE This invention relates to gates for diverting and/or sampling the flow of material, particularly gates which involve diverting the entire flow of material.

Handling materials flowing through chutes and other conduits often requires sampling the material as it flows through the chute. A number of devices have already been proposed for sampling material flowing through chutes.

U.S. Pat. No. 1,966,712 teaches such a prior art sampler intended for sampling grain. The sampler inserts a tube open at one side into a stream of grain flowing inside a larger diameter tube. Only the grain which happens to be intercepted by the inserted tube appears in the sample. Since the area of the opening in the tube is substantially smaller than the cross-sectional area of the larger diameter tube, any segregation by grain size would result in a non-representative sample being obtained.

US. Pat. No. 2,370,260 also teaches the insertion of a small diameter tube open at one side for intercepting a portion of the fine particles flowing through a larger tube. The particles flow through the small diameter tube to a sample container, instead of being retained temporarily in the small tube. Again, the sampler does not necessarily provide a representative sample.

US. Pat. No. 2,683,373 teaches the swivelling insertion of an open-sided small diameter horizontal tube into a vertical chute containing falling grain. The tube opening faces upward inside the chute, the tube being swivelled or rotated 180 upon withdrawal to face the opening downward for automatic emptying. Not only does this sampler intercept only a portion of the material flowing within the chute but it is relatively complicated due to the swivelling feature.

U.S. Pat. No. 3,066,539 teaches the insertion of a grooved plunger into a conduit containing wood pulp flowing under pressure. The pulp incident upon the groove is deflected along the groove to be deposited outside the conduit in a sample container.

The flow of dry, particulate solids flowing through chutes, as in drying and blending circuits is commonly regulated by a number of two-way valves.

In addition to flow regulating, two-way valves are adaptable to flow sampling. When used for flow sampling, conventional two-way valves yield samples which are biased by flow segregation, a phenomenon which occurs especially near'the walls of the chute when a distribution of particle size exists.

, A number of factors contribute to flow segregation, including the size, specific gravity and shape of the particles of material, the slope of the chute, the roughness of the interior surfaces of the chute, and the coefficient of friction betweenthe chute and the individual particles. The result of flow segregation may be an uneven distribution of particles of the same size throughout a cross-section of the flow. Hence, a sampler which intercepts but a portion of the flow of material in the chute inherently yields a sample which is not representative of the entire range of particle sizes occurring in the flow.

It is an object of this invention to provide a gate which ensures either diverting or sampling the entire flow of dry, particulate matter flowing within a chute.

It is a further object of this invention to provide a diverting-sampling gate which is simple in action and construction.

It is a yet further object of this invention to provide a sampling gate which will yield a totally representative sample of the material in the chute, regardless of the flow segregation occurring within the chute.

It is additionally an object of this invention to provide a diverting gate which is readily convertible to a sampling gate.

Other objects and advantages of this invention will become obvious to those skilled in the art.

It has been surprisingly found that it is possible to divert the complete flow of material in a chute, for regulation or for obtaining fully representative samples, by using a simple yet completely effective gate.

The gate is basically a diverting gate which, with the addition of a sample pocket or other sample retainer, may be used as a sampling gate.

The diverting gate comprises, in combination, a substantially upright chute means having at least one wall, a gate means positioned to extend slidably from an inoperative position in which the gate means spans substantially none of the cross-sectional area of the upright chute means through a first opening in one of said at least one wall of the upright chute means to an operative position in which the gate means spans the entire cross-sectional area of the upright chute means, second chute means for receiving diverted material through a second opening in one of said at least one wall of the upright chute means when said gate means is in said operative position, said second chute means having at least one wall, actuating means for extending the gate means across the upright chute means, so that extending the gate means across the entire cross-sectional area of the upright chute means to the operative position results in diversion of the entire flow of material from the upright chute means to the second chute means.

The operation and construction of the diverting/sampling gate will be better understood when considering attached FIGS. 1, 2 and 3 which illustrate a preferred embodiment of the diverting/sampling gate. in these Figures,

FIG. 1 shows a partially cut away perspective view of the preferred diverting gate according to this invention;

FIG. 2 shows a vertical cross-section of the preferred diverting gate in the non-diverting position; and

FIG. 3 shows a perspectigve view of a preferred embodiment of the sampling gate according to the invention showing the chutes in dotted outline.

FIG. 1 shows an upright first chute 10 having a wet angular cross-section and flanged ends. Chute 10 includes inclined gate 12 fitted inside chute 10 which is in the operative position, i.e. the position in which the gate 12 spans the entire cross-sectional area of upright chute l0. Chute 10 includes funnel l4 upstream from the gate to restrict the cross-sectional area of the flow of material to less than the cross-sectional area of the substantially upright chute 10. This helps to prevent the particulate matter from being lost between gate 12 and the walls of the upright chute 10. The gate includes a seal 16 which is shown against the wall of upright chute 10 opposite the opening 18 through which gate 12 slides. Seal 16 prevents particulate matter from leaving upright chute 10 when the gate 12 is moved to the inoperative position, i.e. the position in which the gate 12 spans substantially none of the cross-sectional area of the upright chute 10. For air-tightness, seal 16 includes a gasket 20 which comprises a circumferential strip of sealing material.

The gate 12 also includes side walls 22 which are mounted on the edges of the gate 12 to prevent particulate material from being lost between the gate 12 and the walls of the upright chute 10. The upper edges of the walls 22, the gate 12 and the lower end of funnel 14 are all parallel. The lower the bottom end of funnel 14 is, the less particulate material will be lost between the gate 12 and the walls of upright chute 10.

Gate 12 extends into a second chute 24 which receives particulate material diverted by gate 12. Within second chute 24 is a fixed rod 26 which supports the lower end of gate 12. The other end of gate 12 is supported by rod 28 which passes through the wall of upright chute opposite opening 18. Rod 28 transmits the motion of pneumatic cylinder 30 to the gate 12 via seal 16.

The upright chute 10 has

flanges

44, 46 on its upper and lower ends respectively to permit easy and quick installation and removal of the diverting gate.

FIG. 2 shows the gate 12 in the inoperative position with seal 16 and gasket registering with opening 18.

Rod 28 passes through a removable wall portion 32 which may be removed to permit removing the gate 12 from the diverting gate.

Funnel 14 narrows quickly at its top and extends downward to a bottom edge out parallel to gate 12. The bottom edge of funnel 14 is positioned as low as possible without interfering with the operation of gate 12 or the flow of particulate material into chute 24.

FIG. 3 shows in dotted outline part of the upright chute 10', the flange at its lower end, and second chute 24'. In addition to seal 16 and walls 22', there is mounted on gate 12 an end wall 34 which stops particulate material flowing along gate 12. Taken together, seal 16, side walls 22, gate 12 and end wall 34 form a sample pocket which retains whatever particulate material is incident on gate 12 when moved to the operative position. When the gate is moved to the inoperative position shown in FIG. 3, the sample is removed through the access door 36 in second chute 24, both shown in dotted outline.

When in operation, the diverter gate is in the position shown in FIG. 1. The flow of particulate material enters chute 14 which restricts its cross-sectional area to less than that of upright chute 10. Then the restricted flow of particulate material is deflected by gate 12, as shown by arrow 38. The deflected flow travels along gate 12 into second chute 24 and through chute 24 as shown by arrow 40. When it is no longer desired to divert the flow to chute 24, the pneumatic cylinder is used to move gate 12 into the inoperative position shown in FIG. 2. Now the flow passes downwardly through chute 10 in the direction of arrow 42 deflected only slightly by rod 28. Seal 16 prevents the escape of any particles through opening 18. Pneumatic cylinder 30, which is double acting, is used to move the gate 12 back to its operative position when flow diversion is once again desired.

When the gate 12 is modified as shown in FIG. 3 with walls which form a sample pocket, the diverting gate may be used as a sampling gate. The gate 12 is moved to the operative position by pneumatic cylinder 30 for a fixed period of time. Then gate 12 is moved back to the inoperative position by pneumatic cylinder 36 and the flow sample removed through access door 36. Since the sample is completely representative of the particulate material flowing through chute 10', a quantitative analysis of the sample may be made with confidence.

The sampling gate may not only be used for sampling the composition of the material flowing through the substantially upright chute, but may also be used to quantitatively determine the rate at which the material flows through the chute. The period of time during which the sample is taken may be accurately determined and accurately repeated by using a timing means to regulate the amount of time the gate means is operative. Weighing the sample taken during the measured period of time permits calculating the flow rate in, for example, tons per hour.

Gate 12 is shown in all drawings as being inclined from the horizontal. To encourage the flow of particulate material along it, the angle of inclination of gate 12 should be greater than the angle of repose of the particulate material being handled.

Although the Figures all show gate 12 as moving coaxially with chute 24, gate 12 could also be moved in a direction perpendicular to the plane formed by the upright chute 10 and the second chute 24. In this embodiment, a seal would be mounted at the lower end of and perpendicular to the outer face of one of the walls 22 to register with opening 18 when the gate 12 is removed from chute 10.

Although funnel 14 is shown entirely within chute 10, it may be separate from chute 10 and may be open to the air at its upper end.

In an arrangement which requires no funnel, but which performs in a mechanically equivalent manner, chute 10 ends just above gate 12 or walls 22 or seal 16, whichever is higher, and is cut at an oblique angle similar to funnel 14. Another chute, which is coaxial with chute 10, flares outwardly to gate 12 from a few feet above it, and encloses gate 12, thus permitting gate 12 to be wider than chute 10. Although no funnel, per se, is required, equivalent operation is obtained.

Although rod 28 is shown attached to seal 16, it could alternatively be attached to gate 12.

It will be understood, of course, that modifications can be made in the preferred embodiment of the present invention as described hereinabove without departing from the scope and purview of the appended claims.

What I claim as new and desire to protect by Letters Patent of the United States is:

l. A diverting gate for diverting the vertically downward flow of particulate material comprising, in combination, substantially upright chute means having at least one wall in which is formed an opening, gate means inclined from the horizontal at an angle greater than the angle of repose of the material flowing through the upright chute and positioned to extend slidably from an inoperative position in which said gate means is outside said chute and spans none of the crosssectional area of the upright chute means to an operative position in which said gate means is within said chute and spans the entire cross-sectional area of the upright chute means and thereby serves to divert the flow of particulate material from a vertically downward direction to a direction along the gate means and to said opening, said gate means having at least one upstanding wall mounted on a lower end thereof across the flow of material to stop the flow along the gate means, said gate means having a wall mounted on an upper end thereof and which, in co-operation with said one upstanding wall, forms a sample pocket for diverted material, a substantially air tight seal on said wall on the upper end of said gate means and disposed the second chute means.

2. A diverting gate according to claim 1, wherein the substantially upright chute means includes a funnel upstream from the gate means to restrict the crosssectional area of the flow of material to less than the cross-sectional area of the substantially upright chute.

3. A diverting gate according to claim 1 including at least one side wall mounted on an edge of the gate means parallel to the flow of material to prevent material flowing along the gate means from being lost between the gate means and the walls of the chute wherein said at least one side wall is mounted on an edge of the gate means parallel to the direction of flow.

4. A diverting gate according to claim 1 wherein the substantially upright chute means has a rectangular cross-section.

5. A diverting gate according to claim 1 wherein the actuating means is a pneumatic cylinder.

Claims

1. A diverting gate for diverting the vertically downward flow of particulate material comprising, in combination, substantially upright chute means having at least one wall in which is formed an opening, gate means inclined from the horizontal at an angle greater than the angle of repose of the material flowing through the upright chute and positioned to extend slidably from an inoperative position in which said gate means is outside said chute and spans none of the cross-sectional area of the upright chute means to an operative position in which said gate means is within said chute and spans the entire cross-sectional area of the upright chute means and thereby serves to divert the flow of particulate material from a vertically downward direction to a direction along the gate means and to said opening, said gate means having at least one upstanding wall mounted on a lower end thereof across the flow of material to stop the flow along the gate means, said gate means having a wall mounted on an upper end thereof and which, in co-operation with said one upstanding wall, forms a sample pocket for diverted material, a substantially air tight seal on said wall on the upper end of said gate means and disposed within the upright chute, said seal registering with the opening to minimize the loss of material from the chute when the gate means is in said inoperative position, second chute means in communication with said opening when said gate means is in the operative position and receiving diverted material, and actuating means for extending the gate means across the upright chute means to the operative position in order to divert the entire flow of material from the upright chute means to the second chute means.

2. A diverting gate according to claim 1, wherein the substantially upright chute means includes a funnel upstream from the gate means to restrict the cross-sectional area of the flow of material to less than the cross-sectional area of the substantially upright chute.