US3394649A - Liquid extracting device - Google Patents

Description

, July 0, 1968 H. L. KEMPER ETAL 3,394,649

LIQUID EXTRACTING DEVICE Filed June 27, 1966 5 Sheets-Sheet 1 PULP INVENTORS M 0w yaw/ 52 65mm? 6' 62444340, we.

BY M. 4.. at

ATTORN .9

y 30, 1963 I H. 1.. KEYMPER ETAL 3,394,649

LIQUID EXTRAG'IIING DEVICE Filed June 27, 1966 5 Sheets-Sheet 2 INVENTOR$ H. l 7* (EM/ 6K. 64-01966 F. K0644541 4.

l QM ATTORNEY July 30, 1968 H. L. KEMPER ETAL LIQUID EXTRACTING DEVICE Filed June 27, 1966 5 Sheets-Sheet 5 INVENTORS l-l. rw A/EMPEIE 6601966 6 kantiA ndt.

ATTORNEY.

5 Sheets-Sheet 4 ATTORNEY;

HfL. KEMPER ETAL LIQUID EXTRACTING DEVICE INVENTORS h. if eoece July 30, 1968 Filed June 27, 1966 'II III I If United States Patent 3,394,649 LIQUID EXTRACTING DEVICE Harry Lyn Kemper, Narvon, and George F. Rogalsky, Jr.,

Gladwyne, Pa., assignors to Somat Corporation, Coatesville, Pa., a corporation of Delaware Filed June 27, 1966, Ser. No. 560,474 7 Claims. (Cl. 100-43) ABSTRACT OF THE DISCLOSURE In a hydro-extractor a screw shaft mounting a conical member within a cylindrical sieve concentric with said shaft in which the small diameter end of the cone is within the sieve and the large diameter end of the cone is without the sieve, said cone and said sieve defining a discharge zone the size of which is variable by movement of the sieve relative to the cone.

This invention relates generally to devices for extracting water and other liquids from liquid impregnated ma terials, such as waste and pulp, and more particularly to such a unit including a helical inclined plane in the form of a screw undergoing relative rotation with respect to a surrounding drainage screen.

The device which is the subject of this invention finds particular use with apparatus such as waste disposal apparatus wherein upon treatment of the waste material means must be provided for separating the solids and the liquids from within a slurry. Such waste disposal apparatus in general consists of a tank containing the waste material, fibrous material, garbage and other disposable waste in the presence of a high percentage of water, all being subjected to the disintegrating action of a rotatable impeller having a working face with projecting cutters, such as tungsten carbide, as shown in US. Patent No. 2,729,146. In apparatus of this type there is associated with the tank discharge a means for delivering the waterladen disintegrated material to a liquid extracting device often referred to as a hydro-extractor of the type in which a screw or helical plane is made to undergo rotation within a cylindrical sieve. The hydro-extractor separates the solids from the liquids by withdrawing the liquid from the material received from the disintegrating unit.

The hydro-extractor must be designed so that it will efliciently separate the liquids and the solids and not overload the screw during the process. Additionally, the back pressure or pressure against which the material moves on the helical plane must be maintained within predetermined limits and the device must be capable of operating almost immediately after shutdown during which period materials within the device can dry and harden and often tend to raise the back pressure.

The invention disclosed herein has, as its principal object, the furnishing of a novel liquid extracting device for use primarily with a disintegrating impeller which has markedly increased drainage capability.

Another object of this invention is to provide in a hydro-extractor device means for preventing the plug on the screw from overloading the screw driving means while maintaining the optimum back pressure for satisfactory operation with respect to the solids content of the materials.

Still another object of the invention is to provide in a hydro-extractor means for varying the back pressures of the plug on the rotating screw in accordance with the requirements of a variety of different types of materials which can be passed through the extracting device.

A further object of the invention is to provide a hydroextractor which will not be subject to jamming due to dry plug on the screw when started up after a period of shutdown and one in which the length of the plug can be set to a predetermined dimension.

A liquid extracting device embodying the invention and the manner of using the same is described herein with references to the drawings in which:

FIG. 1 is a side elevation of a liquid extracting device constructed in accordance with the teachings of this invention with portions thereof cut away to disclose certain details of construction;

FIG. 2 is a plan view of the liquid extracting device shown in FIG. 1 with portions cut away to disclose certain details of construction;

FIG. 3 is an end elevation of the liquid extracting device looking lfrom the left end in FIG. 1 with portions cut away to disclose certain details of construction;

FIG. 4 is a sectional view taken along the line 44 in the direction of the arrows in FIG. 2;

FIG. 5 is an enlarged segmentary view of the connection of one of the hydraulic cylinder screen-positioning pistons connected to the screen; and

FIG. 6 is a schematic of the controls.

The liquid extracting device has a frame or chassis consisting of longitudinal side members 10 and 11, supporting end bearing supports 12 and 13 at either end. Transverse baflie 14 through which screw shaft 15 is journaled and baffle 16 provided with an opening through which the screw passes together with bottom plate 18 defining pulp or waste feed chamber 19. Transverse baflles 16 and 20 with arcuate bottom 21 define the drainage chamber. Baffle 20 with transverse baffle 22 defines a pulp discharge zone. In the elevation of FIG. 1, covers 23 and 24 cover the drainage chamber and the pulp discharge zone respectively.

The chassis is supported above a horizontal surface by a pair of front legs 25 and a pair of rear legs 26.

The screw 23 of the hydro-extractor consists of a hollow cylindrical screw shaft 15 having flights 24' providing an inclined surface in the form of a helix of screw surrounding and attached to the hollow shaft. A cylindrical screen or hollow cylindrical sieve 25 surrounds the major portion of screw 23' in the zone beyond the pulp feed chamber 19.

One end of shaft 15 is supported in end bearing 26 in member 12 and the shaft is supported at its remaining end in bearing 27 mounted in member 13. Members 12 and 13 have previously been referred to as end bearing supports.

At the termination of flight 12 at the rear end of the device and to the right, as seen in FIGS. 1, 2 and 4, the shaft 15 is provided with a plurality of through holes 28 which connect the bore 29 of shaft 15 with its outer surface at the zone of the shaft in which holes 28 are provided is surrounded by cone 30 which is mounted on the shaft and rigidly attached thereto. Cone 30 is provided with an enlarged bore 31 overlying holes 28 and bore 31 communicates with the outside surface of cone 28 through a plurality of through holes formed in the cone and indicated in the figures by the numeral 32. A cutter 33 having a cylindrical body 34 and blades 35 is also mounted on shaft 15 and spaced from cone 30 by cylindrical spacer 36 with the ends of blades 35 overlying the end of cone 30. The end of cone 30 adjacent flights 24 is the small diameter end of the cone and the end of the cone which is beneath the blades 35 is the large diameter end of the cone. Cutter member 33 is keyed to shaft 15 so that there is no relative motion between shaft 15, cone 30 and cutter member 33 when the shaft is rotated.

Means are provided for rotating screw 23 consisting of drive motor 37 supported by the chassis, drive sheave 38, drive belt 39, driven sheave 40, reducer 41 and coupling 44. Belt 40 is surrounded by belt guard 45.

The bottom 21 of the drainage chamber slopes downwardly forwardly (to the right in FIGS. 1 and 4) and is provided with drainage means at its lowermost zone consisting of spout 46, hose 47, elbow 48, pipe 49, pump 50 and hose connection 51'. Thus, as will be explained below, water removed from the material and passing through the sieve 25 will fall by gravity into the drainage chamber and be removed therefrom by the action of pump 50 out of connection 51.

Also, the purpose of which will appear below, a housing 51 surrounds the open end of the bore of shaft and is connected with the drainage chamber through hose 52. The purpose of this will be explained in detail below. However, its purpose in general is to receive water flowing out of the bore of shaft 15 and return it to the drainage chamber.

The screw 23, as mentioned previously, is disposed for rotation within screen 25. The screen is supported in the unit by screen guide assembly 53 consisting of straps 54 and 55 which are spaced from one another longitudinally of the screen and which encircle the screen and which are attached to one another by a plurality of ribs 56. Hydraulic cylinders 57 are supported at their ends by brackets 58 attached to bearing support 13 and extend toward the screen guide assembly 53 with the piston rods 59 of the hydraulic cylinders extending through openings in baflie for attachment to the screen guide assembly 53 as viewed most clearly in FIG. 5 wherein it is seen that brackets 60 which are attached to ribs 56 are in turn attached to the ends of the piston rods 59 by clevis rod 61, pin 62, spacer 63, clamps 64 and bolt 65. The hydraulic cylinders are identical and their connections to the screen guide assembly 53 are identical.

Facing ears 66 project from strap 54 and facing ears 67 project from strap 55 respectively providing channels within which screen bar guide 68 is disposed.

Screen bar guide 68 is supported at one end by bafile 16 and at its other end by bafile 20 and extends parallel to shaft 15 providing a guide for the screen when the screen is moved longitudinally and also aiding the hydraulic cylinder pistons in preventing the rotation of the screen during operation of the device. The numeral 69 indicates the zone between the outer surface of cone 30 and the inner surface of screen 25.

In use the liquefied waste material is placed within chamber 19 with motor 37 energized so that screw 23' is rotated in the direction of the arrows as indicated in the figures with the solids and liquid material moving to the right along the screw flight toward the cone 30. The material moves within the screen toward the discharge zone 69 with the specific discharge area defined by the end of the screen and the outer surface of cone being annular. As the material moves under the rotation of the screw, the deliquefied material moves to the right as liquid is drained off through screen 25 into the discharge chamher. The solids deposited by the screw in the annular area following the terminus of the helical flight and before the discharge opening are referred to as the plug. The annular discharge area is determined by the relative positions of screen 25 and cone 30. Hence with screen 25 toward the right, the annular discharge area will be less than with screen 25 to the left. The positioning of screen 25 longitudinally with respect to cone 30 and hence the area of discharge is established by the position of pistons 59 of the hydraulic cylinders 57.

As stated above, the shaft 15 is rotated by motor 37. Means are provided for determining the load on screw 23' and shaft 15 and positioning the screen 25 so as to provide a load on screw 23' and shaft 15 which is predetermined with respect to the optimum drainage conditions for the material within the device. The point of the extreme left hand position of the screen in FIG. 4 is indicated by the line yy. Depending upon the nature of the pulp or waste material, optimum drainage will result from a predetermined specific back pressure or force developed by the plug at zone 69. This, in turn, is determined by the area of the annular discharge zone which, in turn, is determined by the relative position of cone 30 and screen 25. Hence the provision of suitable means to determine the load on shaft 15 will determine the back pressure and the hydraulic pistons 57 can be adjusted accordingly to position the screen 25.

In the particular embodiment shown herein as one means of determining and positioning screen 25 relative to cone 30, a current sensing device is provided in the electrical input circuit to motor 37 and the device is connected with hydraulic cylinder controls 70 for positioning the pistons 59 of the hydraulic cylinders with respect to the current flow in the electrical input circuit to motor 37. Variation in the current flow will be sensed and cause a re-positioning of pistons 59. In this embodiment therefore a predetermined current in the input circuit to motor 37 will result in the optimum positioning of screen 25 and upon increase of pressure beyond the desirable amount the additional loading on shaft 15 will result in additional or increased current in the input to motor 37 which will be sensed and through controls 70 result in the re-positioning'of the screen 25.

Thus a constant optimum pressure on the plug of solid material discharging from the screw can be maintained. This provides for optimum drainage and prevents a runaway condition wherein the plug could become tighter and tighter and finally overload the motor to a damaging point. The provision of holes 28 in the shaft and holes 32 in the cone permits water drainage not only through sieve 25 but at the plug also through cone 30 and shaft 15 and out of the end of shaft 15 into housing 51 and thence to the drainage chamber.

Cutting blades 35 project within the annular discharge zone 69. The cutter bodies 34 are keyed to shaft 15 at longitudinal keyway 71 provided therein which allows the cutting members, although prevented from rotational motion relative to the shaft, to be adjusted longitudinally. The cutting blades perform the function of determining the length of plug by cutting the material as it is projected against the blades and through the annular discharge zone. These blades also aid in the prevention of clogging of the discharge area.

Screen 25 can be pulled back along screen bar guide 68 in order to fully expose the plug and allow for cleaning the same so that when the unit is started up again after a rest period the device is ready for operation.

Lands 72 are provided on the under surface of hood 73 which is hingedly connected to baffle 16 at 74 and project downwardly from the hood and toward screw 23' while being elongated in the direction of shaft 15 in order to prevent the material as it is initially fed into screw 23 from rotating, thus insuring that the material moves in the direction of cone 30.

FIG. 6 is a schematic of the control system of the embodiment disclosed herein. As seen in FIG. 6, drive motor 37 supplied by electrical line has coupled into its input circuit motor load recorder and transmitter 81, time delay 82 for motor recovery, and power operated four-way valve 83. The hydraulic pump 84 feeds valve 83 through flow control adjustment valve 85. The fourway valve 83 is connected with hydraulic cylinders 57 through compensated flow control valves 86. The pistons of cylinders 57 as described above are coupled to screen 25 for movement thereof. Hence the motor load recorder and transmitter 81 in main power source line 80 determines the longitudinal position of screen 25 in accordance with the fiow of current in line 80.

Hence it is seen that a device has been provided which will insure optimum drainage of waste material.

In the preferred embodiment the holes 32 are provided in cone 30 and holes 28 in shaft 15. However, in certain applications it has been found that the proper results can be achieved by utilization of a solid shaft and elimination of means for draining the plug through the cone and shaft.

Thus, among others, the several objects in the invention, as specifically aforenoted, are achieved. Obviously, numerous changes in construction and rearrangement of parts might be resorted to without departing from the spirit of the invention as defined by the claims.

We claim:

1. 'In a hydro-extractor of the type designed to receive a mixture of liquid and solids and to form a substantially solid dry plug of material therefrom, in combination, a shaft, a helical screw formed on a portion of said shaft, means for introducing said mixture onto said screw, a cylindrical sieve surrounding said screw and concentric with said shaft, a conical member supported by said shaft with its small diameter end within said sieve and its large diameter end without said sieve, a discharge space defined by said conical member and said sieve, means for rotating said screw within said sieve and emitting liquid from said mixture through said sieve to form and move said plug axially toward said discharge space, sensing means for determining the load of said plug on said screw, said sieve being movable longitudinally of said conical member to vary the size of said discharge space and positioning means responsive to said sensing means for positioning said sieve relative to said conical member in response to the load of said plug on said screw.

2. A hydro-extractor in accordance with claim '1 in which said positioning means includes a hydraulic cylinder having a piston therein the position of which is determined by the load of said plug on said screw and said piston is operatively attached to said sieve.

3. A hydro-extractor in accordance with claim 2 in which guide means are provided defining a longitudinal track for movement of said sieve.

4. A hydro-extractor in accordance with claim 1 in which said shaft is hollow and drainage holes are formed in said conical member and said shaft beneath said conical member and means are provided for withdrawing liquid from the bore of said shaft.

5, A hydro-extractor in accordance with claim 1 in which cutting blades are provided within said discharge space and which cut said plug upon relative rotation of said plug and said cutting blades.

6. A hydro-extractor in accordance with claim 5 in which the axial position of said cutting blades is adjustable to determine the length of said plug.

7. A hydro-extractor in accordance with claim 1 in which an end of said screw is disposed within a feed chamber and elongated lands parallel to the axis of said shaft overlie said shaft and engage said mixture of liquids and solids whereby materials disposed upon said end of said screw will be prevented from rotating with said screw.

References Cited UNITED STATES PATENTS 647,354 4/1900 Anderson -98 2,340,009 1/ 1944 Meakin 100 147 XR 2,658,445 1 1/ 1953 Wilen et al. 100-147 XR 3,034,421 5/1962 Pence 10043 3,062,129 11/1962 Wandel 10043 3,143,956 8/1964 Hurtig 100-43 BILLY J. WILHI'IE, Primary Examiner.

Images