US2681610A - Paper machinery - Google Patents

Description

June 22, 1954 SCHRQCK 2,681,610

PAPER MACHINERY Filed July 27, 1951 INVENTOR. RAYMOND I... Scmzo cm WWQM I ATTORNEYS Patented June 22, 1954 UNITED STATES ATENT OFFICE PAPER MACHINERY Application July 27, 1951, Serial No. 238,988

Claims.

This invention relates to apparatus for separating grit and other solid particles from a liquid suspension such as paper making stock, and the invention has special relation to the removal of the separated reject particles from cleaning and separating apparatus of this character, including both centrifugally operated ap- .quantity of liquid from the separating apparatus at a point where the separated reject material collects within the apparatus, but in such operations it then becomes necessary either to conduct the resulting mixture of liquid and reject to the sewer, or else to concentrate by a further straining or drying treatment. In either case, the liquid lost with the reject material or the further concentrating treatment add undesirably to the cost of the separating operation and correspondingly reduce efiiciency.

Improved results from the standpoint of simplicity, convenience and economy have been obtained by equipping cleaning and separating apparatus of the above character with a continuously operating reject removing device comprising a motor driven conveyor screw located in position to receive the separated reject material and mounted in a complementary tube having a closure door opening exteriorly of the apparatus and counterbalanced to a normally 'closed position, examples of such constructions being disclosed, for example, in the copending applications of Joseph Baxter, Jr., Serial No. 57,559 filed October 30, 1948, now Patent No. 2,622,795, and Stephen A. Staege, et al., Serial No. 163,112 filed May 20, 1950, now Patent No. 2,645,346, and both assigned to the same assignee as this application. In operation, the conveyor screw collects and compacts the reject material into the form of a relatively solid slug between the end of the screw and the closure door, and then as additional reject accumulates and is forced against this slug, the door will be opened against its counterbalance to effect gradual discharge of the reject, in the form of a damp Sludge roughly comparable in consistency to sand .free discharge.

Several factors are important in obtaining optimum efficiency in the operation of a reject removing device of this character. For example, the closure door should be sufficiently counterbalanced to provide an adequately tight seal against the maximum hydraulic pressure within the body of the apparatus in order to assure that no leakage of liquid occur, particularly when the device is starting up and before there has been sufficient time for the slug of reject material to accumulate. Also, the closure door should provide sufiicient resistance to movement of the slug of accumulated reject material to cause proper compaction of the slug before the door opens in order to assure that this slug will provide the desired continuosuly effective seal after the door opens, and on the other hand the door should not oiier such high resistance to opening as to cause compaction of the reject to such extent that it will lock in place against the desired discharging movement.

These factors with respect to the closure door also effect the conveyor screw. In particular, the comparatively large counterbalancing force required for proper operation of the door as described imposes a corresponding load on the screw, and especially on the end portion of the screw which is required to drive the accumulated slug of reject material through the reject tube with sufiicient force to open the door and to hold it open for the desired continuous extrusion of reject material. When apparatus of this character is utilized for cleaning paper making stock, and particularly waste paper and other comparatively dirty stock in which the reject includes a high percentage of gritty particles, the abrasive forces on the screw tend to be severe, especially on the end portion of the screw in contact with the slug, and sometimes may be so severe as actually to wear away the end flight of the screw in a comparatively short time if the device is not operating properly.

It is accordingly a principal object of the present invention to provide a reject removing device of the above character wherein the closure door is constructed and mounted to establish proper sealing action at all times against the hydraulic pressure within the cleaning and separating apparatus but which at the same time will open and remain open without undesirable load on the conveyor screw when the proper slug of reject material has accumulated between the end of the screw and the door in sufficient quantity for discharging.

A further object of the invention is to provide a reject removing device as discussed above wherein the closure door is mounted. for swinging movement in a substantially straight line between its closed and opened positions and wherein a counterbalancing mechanism. is incorporated for the closure door which offers maximum counterbalancing force in the closed position of the door and decreased counterbalancing force after the door has been opened in order to minimize the operating load on the conveyor screw. 7

Other objects and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims.

In the drawing- Fig. l is a View in side elevation, partly broken away, showing a vortex type of cleaning and separating apparatus embodying a reject removing device constructed in accordance with the present invention;

Fig.2 is a detail view in side elevation illustrating the closure door unit for the reject removing 'device and with the door shown in closed position;

Fig. 3 is an enlarged view similar to Fig. 2

showing the door in open position;

Fig. 4 is a front elevational view of the door unit; and

Fig. 5 is a partial top plan view of the unit.

Referring to the drawing, which illustrates a preferred embodiment of the invention, Fig. 1 shows a vortex separator generally of the construction disclosed in the above noted Staege et a1. patent, which includes a main base is supporting a cylindrical casing i enclosing a son arating chamber I2. A center section 53 is positioned between the casing i l and base it to form an extension of chamber l2, and it includes an outlet conduit 1! 5 which projects upwardly for a substantial distance within chamber i2 and is curved forwardly through section 3 for attachment at l 5 to a suitable discharge pipe. An inlet conduit 2c is mounted on the upper end of casing H, and it includes a tangentially arranged inlet connection 2! at its upper end. A helix comprising'a core 22 and a helical vane 23 is mounted within the inlet conduit 28, and the core 22 extends downwardly through the upper part of the chamber l2 and into the upper end of the outlet conduit !5 as shown.

The adjacent ends of the inlet and outlet conduits i5 and 2d are spaced axially to provide an annular gap 25 between the lower end of the inlet conduit and the upper end of the outlet conduit, and in operation, the stock entering the ap- Z I paratus is provided with a whirling motion by the tangential arrangement of the inlet connection 2! and the helical vane 23 before it reaches the chamber 12. The centrifugal force resulting from this whirling motion causes heavy particles in the stock to be thrown radially through the discharge passage or gap 25 as the clean stock flows across this gap into the upper end of the outlet conduit [5. These discharged heavy particles will also whirl in a larger spiral as they are assignee as this application, which discloses a ail) T ii

composite screw construction especially satisfactory for use as screw in Fig. 1.

This conveyor unit is provided with an outlet door unit which includes a main casting d8 bolted to the base it at ll and receiving the forward end of sleeve 33 therethrough to form a continuation of the conveyor passage. A bracket 42 is mounted on top of castin st and forms the support for the closure door plate 44, which has a conical nose piece :5 arranged to fit within and seal the outer end of sleeve 33 in the closed position of the door. The bracket 32 is mounted on casting GE! by means of a pair of yoke arms 46 projecting upwardly at opposite sides of the casting, and the rearward end of bracket 42 is bolted at ll to the top of the casting 59.

The mounting for door plate M includes a parallel linkage providing for movement of the door with respect to the conveyorpassage and sleeve 33 while maintaining the longitudinal axis of the door substantially parallel with the axis of the screw 35. An arm 56 is pivoted to the front of the door plate at 5! and to the front end of bracket 2 at 52. Behind arm 56 is a pair of links 55, one on each side of casting 49, and the upper end of each arm 55 is pivoted at 5t to bracket 62 while the lower end of each of these arms 55 is pivoted in a yoke portion 5'! projecting rearwardly from one or the other of the side extensions with 55 on door plate Ml, with the pivots for arms 55 being equally spaced from the corresponding pivots for arm 59. As shown, the upper pivot axes 56 for the arms 55 are located in the same horizontal plane with the pivot 52 of arm 50, and the lower pivot axes of the arms. and are all located on the central plane of the door plate and its nose piece 45 in such relation with the pivot axes of the upper ends of these arms that the fully closed and fully opened positions of the door shown in Figs. 2 and 3 are approximately equally removed from the lower dead center position of the door, so that in the operating movement of the door, its longitudinal axis is maintained substantially parallel with the screw 35, and there is minimum change of its vertical position with respect to the end of the sleeve 33.

The counterbalance for door t l includes counterweights to on each side of the device and each mounted on an elongated lever arm 6! keyed to a shaft 62 projecting at opposite ends from bosses 53 on a bracket portion 8 extending along'the underside of casting it, and a short lever arm 65 is also keyed to each end of shaft 62 to form a bell crank with the adjacent arm 6!. The upper end of each lever arm 65 is'pivoted to a pair of links as having their opposite ends adjustably connected by an eye bolt 61 with the extension portions 58 of the door plate. Thus the counterweights it provide a constant counterbalancing force urging the door is towards the closed position of its nose plate 55 in the outer end of sleeve 33.

It will be noted that in the closed. position of the door shown in Fig. 2, the counterweight arms 6| extend in nearly horizontal direction so that the effective counterbalancing action of the weights 6!! will be near a maximum, whereas in the open position of the door shown in Fig. 3,

the counterweight arms El extend upwardly at a substantial angle to the horizontal, producing l corresponding shortenin of their effective length with resulting decrease in the counterbalancing load. Thus in the closed position of the door,

there is high counterbalancing force exerted in the direction to hold the door closed, but as the door opens, this counterbalancing force is decreased.

In the operation of the vortex separator as shown in Fig. 1 in conjunction with this reject door unit, the reject material discharged through gap 25 into the chamber l2 ultimately settles to the bottom of the chamber and through the throat 3i! into the sleeve where it is picked up and carried by the screw 35 towards the outer end of the sleeve and the door dd.

It is desirable to have the screw terminate at a position spaced from door nose piece 65 by an appreciable distance as shown, for example six to eight inches,

and under these conditions the accumulated reject first forms a relatively solid slug between the end of the screw and the door. The counterbalancing mechanism for the door is correlated with the hydraulic pressure within the chamber I2 to hold the door closed against both the hydraulic pressure and the initial pressure of the accumulated reject until a slug has been formed which is suihciently solid to seal the end of sleeve 33 even if the door were completely opened but which will at the same time move through the sleeve for discharge as the door is opened.

When a slug of this desired consistency has been formed, then as additional reject accumulates and is forced against the inner end of the maining in and moving through the end of the sleeve 33 will effectively seal against free discharge, and since in the accumulation of the reject slug, the water will be effectively squeezed out and back into the body of the device, the

material as discharged is in the form of a damp sludge containing practically no more liquid than may adhere to the individual particles therein, so that this sludge can be readily handled by shovels or otherwise conveniently loaded for removal to a dump or other waste receptacle.

The construction and mounting of the closure door as shown, which provides for its straight line movement and also for the change in eifective counterbalancing force as the door opens, is of material aid in providing improved and more efficient operation of the reject removing device. The desired initial accumulation of the reject slug is readily effected without danger of leakage, but thereafter the door opens without unduly loading or straining the conveyor screw and its drive motor, since the movement of the door is substantially along the axis of the screw and discharge sleeve 33 so that the load on the screw is balanced equally around the inner periphery of the sleeve 33.

In particular, the easy opening action of the door, and its reduced resistance to discharge after it is opened, combine to reduce the working load on the screw 35, and this is an important factor in reducing abrasive wear on the screw and hence in contributing to a longer useful life for all of the parts. The pointed formation of the door nose piece is also an aid to efficient and economical operation, hence it acts in use to prevent unduly tight packing of the reject and to distribute the force evenly around the door for easy opening at the proper moment for maintained low operating stress on the screw.

While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. An outlet assembly for a reject removing device of the character described for handling solid particles and including a discharge tube having a conveyor screw rotatably mounted therein, comprising means forming an outlet from said tube spaced from the end of said screw and substantially coaxial therewith, a closure door for said outlet, a plurality of supporting arms for said door, means pivoting one end of each of said arms to said door on axes lying transversely of said outlet in a plane coincident with the axis of said tube and screw, means pivoting the other ends of said arms to said outlet means in a plane substantially parallel with the other said plane to support said door for movement towards and away from said outlet while maintaining the longitudinal axis of said door substantially parallel with the axis of said outlet and said screw, and means for counterbalancing said door to the closed position thereof providing for opening of said door by the pressure of accumulated solid particles between the end of said screw and said door, said linkage connection being locateol entirely externally of said outlet means and forming the entire support for said door to leave said outlet unobstructed by said door upon opening thereof.

2. An outlet assembly for a reject removing device of the character described for handling solid particles and including a discharge tube having a conveyor screw rotatably mounted therein, comprising means forming an outlet from said tube spaced from the end of said screw and substantially coaxial therewith, a closure door for said outlet, a plurality of arms pivoted to said outlet means and said door to form a parallel linkage connection therebetween providing for movement of said door with respect to said outlet while maintaining the longitudinal axis of said door substantially parallel with the axis of said outlet and said screw, means for counterbalancing said door to the closed position thereof providing for opening of said door by the pressure of accumulated solid particles between the end of said screw and said door, said linkage connection being located entirely externally of said outlet means and forming the entire support for said door to leave said outlet unobstructed by said door upon opening thereof, and means responsive to movement of said door .from the closed to the opened position thereof for decreasing the effective counterbalancing action of said counterbalancing means to provide decreased resistance to thedischarge of material from said outlet as said door is opened.

3. An outlet assembly for a reject removing device of the character described for handling solid particles and including a discharge tube having a conveyor screw rotatably mounted therein, comprising a hollow body member adapted for mounting at the outer end of said discharge tube to form an outlet substantially coaxial with said tube, a closure door for said outlet, a plurality of arms pivoted in parallel relation to said body member and to said door to form a parallel linkage connection between said door and said body supporting said door for movement with respect to said outlet while maintaining the longitudinal axis of said door substantially parallel with the axis of said tube, and means carried by said body member for counterbalancing said door to closed position providing for opening thereof by the pressure of said solid particles accumulated in the end of said tube between said screw and said door.

4. An outlet assembly for a reject removing device of the character described for handling solid particles and including a discharge tube having a conveyor screw rotatably mounted therein, comprising a hollow body member adapted for mounting at the outer end of said discharge tube to form an outlet substantially coaxial with said tube, a closure door for said outlet, a plurality of supporting arms for said door, means pivoting one end of each of said arms to said door on axes lying transversely of said outlet in a plane coincident with the axis of said outlet, means pivoting the other ends of said arms to said body member in a plane substantially parallel with the other said plane to support said door for movement towards and away from said outlet while maintaining the longitudinal axis of said door substantially parallel the axis of said outlet and said screw, and means carried by said body member for counterbalancing said door to closed position providing for opening thereof by the pressure of til said solid particles accumulated in the end of said tube between said screw and said door.

5. An outlet assembly for a reject removing device of the character described for handling solid particles and including a. discharge tube having a conveyor screw rotatably mounted therein, comprising means forming an outlet from said tube spaced from the end of said screw and substantially coaxial therewith, a closure door for said outlet, a plurality of arms pivoted to said outlet means and to said door to form a parallel linkage connection therebetween providing for movement of said door with respect to said outlet while maintaining the longitudinal axis of said door substantially parallel with the axis of said outlet and said screw, a counterbalance for said' door including a weight arm, means forming a pivotal mounting for said weight arm on said. outlet means and means connecting said weight arm with said door to counterbalance said door to the closed position thereof providing for opening of said door by the pressure of accumulated solid particles between the end of said screw'and said door, said connecting means being constructed to locate said weight arm in generally horizontal position in said closed position of said door and to cause movement of said weight arm towards the vertical upon opening of said door to reduce the effective counterbalancing force of said weight arm as said door opens.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 19,421 Helton Feb. 23, 1858 4232 10 Graebert Mar. 1.1, 1890 446,002 McGowan Feb. 10, 1891 585,800 Toulouse et' al. July 6, 1897 647,354 Anderson Apr. 10, 1900 731,734 Anderson June 23, 1903 909,409 Herschler Jan. 12, 1909 1,331,115 Luby et a1 Feb. 17, 1920 2,246,045 Hirschberg June 17, 1941

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