US2822097A - Centrifugal trickle valve - Google Patents

Description

Feb. 4, 1958 w. J. LEE

CENTRIFUGAL TRICKLE VALVE Filed Aug. 10, 1955 INVENTOR "Wilfred J11 ee ATTORNE United States Patent CENTRIFUGAL TRICKLE VALVE Wilfred J. Lee, East Syracuse, N. Y., assignor to United States Hofiman Machinery Corporation, New York, N. Y., a corporation of New York Application August 10, 1955, Serial No. 527,541

4 Claims. (Cl. 214-17) This invention relates to rotary valved impeller means for handling substantially dry powdered or granular materials and particularly to such means rotatably associated with a rigidly mounted hopper for flowing such material to the impeller or rotary member.

One of the objects of this invention is to provide an improved throwing element of simple and practical construction and accurately controllable operation.

Another object is to provide simple and adjustable means which may be conjointly operable by centrifugal force and by gravity action, automatically to control the rate of discharge of material from said throwing member.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly consists of the features of construction, combinations of elements, and arrangement of parts as will be exemplified in the structure to be hereinafter described and the scope of which will be indicated in the following claims.

In the drawings which show one or more of the various possible embodiments of'the invention Figure 1 is an elevation and vertical section of apparatus showing a practical and efiicient embodiment of the invention;

Figure 2 is, in part, a plan view, and, in part, a horizontal cross-section taken on line 22 of Figure 1 and showing by solid lines flap valves or dampers in closed position, and, by broken lines, in one of the active positions assumed during operation of the device; and

Figure 3 is a vertical cross-section taken on line 3-3 of Figure 1 and showing in elevation the lower end of a vertical hopper or funnel discharge tube, bearing parts for the rotary element being omitted.

Like reference characters relate to like parts throughout the drawings and specification.

Rotary members or impellers of the class to which this invention belongs have long been used for separating and distributing particles, as, for instance, in grain grading machines or in air cleansing and ventilating apparatus. Such members have heretofore been made in many different forms. Some have relied entirely upon centrifugal action to discharge the material into one or more bins or other catching and storage devices. In some cases the impellers comprise rotatable disks, or boxes, having open ended radial discharge passages, extending outwardly from a central material receiving chamber into which the material is deposited through a down tube leading from a hopper, or the like, the material being brought to said hopper in a current of air, or otherwise, as by gravity.

Generally, in the case of relatively fine substances, the particles are passed through the hopper or funnel in a stream of air either under pressure or by suction and which may vary both in pressure and velocity.

The rate of discharge from the rotating element in some cases must be very accurately controlled. In some, the rate of discharge is under the control of an adjustice able damper in the down tube of the hopper which by regulating the supply to the rotary'member, alters the discharge therefrom. in 'all cases the rate of discharge is affected by the speed of rotation of the thrower, or impeller, by causing a stronger or weaker flow of the airborne material toward the mouths or outlets thereof. -It will be understood that the force attained by the centrifugally thrown particles will depend also upon the specific gravity and/ or weight of the carried material.

In some constructions the force of gravity has also been taken into account either to counter or aid the centrifugal action in controlling the path of discharged particles."

The variations mentioned above have all been more or less effective where the question is' merely one of distribution of material to circumferentially arranged receiving bins or hoppers, and the question of accurate quantity discharge was'not important.

When, however, accurate quantity discharge is important, as for instance in the. case of removing dust collected in ventilating'apparatus, it has been found necessary to adopt means located adjacent the outlets of the impeller passages by the adjustment of which the discharge may be ascertained with mathematical accuracy.

Such means will now be described in connection with a general description of the present embodiment of the invention, with specific reference to the'accompanying drawings, which disclose a central rotary impeller member or valve 2 adapted to convey material from a dust collector or hopper 4, under vacuum, though it could be atmospheric pressure, to a funnel shaped binor hopper 6. The hopper 4 is rigidly mounted in any suitable manner and provides a support 8 for an electric drive motor 10.

A tubular discharge member or down tube 12 depending from the hopper 4 serves to discharge dust, or other material, collected in the hopper 4, to the rotatable impeller or throwing member 2, which then discharges into the stationary bin 6.

Suitable bearings 14 carried by upper and lower cages 16and 18 are disposed between the down tube 12 and a concentric tubular and rotatable member 20, of greater diameter than the down tube 12. A peripheral seal 21, bearing against member 20 around to circumference is mounted between cooperating parts 22 and 23 of the top side or lid 24 of bin 6.

A belt pulley 10" is keyed to motor shaft 10 and, by means of belt '26 and pulley 28, eifects rotation of the tubular member 20, which carries at its lower end the rectangular elongated box-like impeller member-"2, the

latter having a controllable'discharge valve, as will be explained hereinafter.

The lower end of the down tube 12 extends through the upper side 2' of the impeller 2, to a point below a central circular opening 13 in said upper side 2.

From the foregoing it will be understood that the laterally extending portions of the throwing member 2 are supported for rotary movement within the upper portion of the receiving bin or hopper 6; and it should be noted that the said rotary movement is achieved by means of a power motor, which may be either of the constant or variable speed type and is operably connected to drive the whole rotatable assembly.

In order to attain more accurate control of the discharge of material from the impeller, valve or damper means are associated with the months or open ends of the member 2. As shown in Figure 1, brackets 31 extending above the top plate 2' serve pivotally to support (as at 28) the opposed dampers or flap valves 30, which latter normally tend to close against the said ends, by gravity action and by the back pressure caused by the vacuum in hopper 4, to vary the eifective area of the discharge mouths of member 2 to any desired extent, thus controlling material with speed sufficient to produce effective centrifugal action, entailing not only outward pressure of the dust and other material against the inner sides of the flaps, but also opening movement of the flaps abouttheir pivots 28', material maybe discharged at a predetermined rate.. i

, The extent or rate of discharge will depend upon several factors, one of which is the specific gravity of the material being moved. The horizontal centrifugal force exerted by the material against the inner sides of the flaps and the weight of the flaps 29' will act as a force to open the same. The moment of force resulting from the counter weight of the flaps 29, with reference to their pivots 28, and the force of vacuum act in opposition to the opening force and tend to close the flaps. These'opposing forces may each be ascertained with mathematical accuracy when the various data of construction, speed of rotation, density, degree of vacuum, etc. are known.

In Figure 1, means are shown for loading the flaps either to add to, or affect their gravity resistance to centrifugal operation. At the ends of the impeller member 2, the flap valves 30 are shown as supporting above their pivots 28' adjustable counterweights 29 which, in the position of the closed flap, will tend to increase the resistance of flap opening as mentioned above.

However, as the flaps are opened the weights 29 takes positions respectively to the right and left of the pivotal axes, in which position the counterweight action of the flap valves themselves is decreased. It will be understood that the Weights 29 may consist of a plurality of removable weight units loosely surrounding an upstanding damper projection 30, or may consist of a single weight unit adjustably movable, as by threaded connection with projection 30', to positions nearer to or further away from the pivot 28'. Instead of the adjustable weights just described, weights of the kind shown by broken lines at the right end of rotatable member 2 may be employed. By the latter arrangement the weightsupporting member may be an outwardly extending support 30", and the counterweight 29' be suitably arranged for adjustment to dilferent positions, inwardly or outwardly, along the said support 30". In the case of this alternative construction the effect of the weight 29 would be controlled by changing its position upon the support 30".

From the foregoing it will be seen that this invention is one well adapted to attain the objects hereinbefore set forth, and to accomplish other advantageous results in a simple, practical and economical manner.

As many possible embodiments may be made of this invention without departing from the scope thereof, it is to be understood that all matter set forth or shown in the drawings is to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A device of the character described for feeding granular and powdered material at a constant controllable rate, said device comprising a large receiving bin, a horizontally disposed hollow thrower arm, a short vertical tube-like member having one of its ends attached at right angles to said arm, bearing means for rotatably mounting said member in vertical position generally centrally in an end of said bin, means for rotating said member and with it said arm at high speed, material supply means at the other end of said tube-like member through which powdered material and the like can be introduced into said arm and centrifuged out its ends, and at least one flapper plate pivoted on an end of said arm and movable to close said end when said arm is not rotating and to open said end by moving outward under centrifugal force when said arm is rotating.

2. The combination of elements as in claim 1 wherein each end of said arm carries a plate and each of said plates is hinged along a top edge of said arm and said plate hangs down over the end of said arm when it is not rotating and swings outward away from said arm when it is rotating.

3. The combination of elements as in claim 2 in further combination with a concentrated counterweight adjustably mounted on each of said plates and serving to adjustably determine the amount said plate swings away from the end of said arm when said arm is rotating at a given speed.

4. A pulverulent-material feeding apparatus wherein the material is to be fed at an accurately controlled rate, said apparatus comprising means for supplying said material, an inverted conical bin into which said material is to be discharged, a short tube rotatably mounted in the center of the large end of said bin and vertically positioned, a hollow arm attached symmetrically at right angles to the lower end of said tube and lying horizontally within the upper end of said bin being rotatable along with said tube and with its two open ends pointed toward the wall thereof, two flap plates each hinged horizontally athwart a respective end of said arm and positioned to hang down and close said end when said arm is at rest and to swing outward away from said end under centrifugal force when said arm is rotating, and two small counterbalance weights, each threaded on a shaft carried on a respective one of said plates whereby adjustment of said weights can control the distance said plates swing outward when said arm is rotating.

References Cited in the file of this patent FOREIGN PATENTS 219,909 Germany Mar. 11, 1910

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