US3817459A - Device and process for reclaiming used wood - Google Patents

Abstract

A used wood reclaiming device has a receiving means for material including miscellaneous used wood pieces and accompanying debris. The received material is conveyed to a water tank to effect a separation of floating material from sinking material. The sinking material is conveyed away from the tank while the floating material is conveyed to a wood mill shredding the wood pieces into small particles. Metal is magnetically removed. The remaining shredded wood is then carried to a sizing device from which the smaller particles are sent to storage while the larger particles are carried away.

Description

United States Patent 1 1 Keller et al.

[ DEVICE AND PROCESS FOR RECLAIMING USED WOOD Inventors: David Keller, 7601 14th Ave,

Sacramento, Calif. 95820; Henry Keller, Rt. 1, Box 188A, Sacramento, Calif. 95632 Filed: Jan. 2 1973 'Appl. No.: 320,274

Int. Cl. .l B02c 21/00 Field of Search 241/20, 24, 25, 28, 30, 241/38, 68, 77, 79.1

References Cited UNITED STATES PATENTS 5/1972 Brewer 241/24 X June 18, 1974 Marsh 241/20 Primary Examinew-Granville Y. Custer, Jr. Attorney, Agent, or Firm-Lothrop & West 57] ABSTRACT 9 Claims, 10 Drawing Figures Brooks 241/28 RECEIVING 5T. 7 CHAIN coNv. -'l6 1 MAT. TRANSF.

BELT com. 32

I L wATER TANK T 1 1 1 39 1 REFUSE ROLLER WATER PUMP FLoATERIwATER LEVEL) CHAIN CONV. SEPARAT. 8| 3 JETS SOLENOID OPERATED MAlN INTAKE a BRAIN 1 5| -76 4o SHAKER P scREEN v TAKE AWAY '02 BELT CONV.

1 93 BOARD a wooo CHIPPER CLEANING BELT CONV. HOG BRUSH 1 I 1 96 CHIPS CHAIN CONV. B

CHAIN CONV. COLLECTING DRUM I03 l CHIPS BELT coNv. (MAG. PULLEY) /IO4 I06 .1 I05 MAG CHUTE a I BELT coNv. coLLEcT. DRUM SHAKER SEPARATOR 1 1 1 1' 1 1' CHUTE a CHIPS CLEAN CHUTE BLOWER coLLEcT. DRUM BELT coNv. coARsE NIAT FINE MAT.

(MAG. PULLEY) REcYcLE 1 1 123 no CHUTE SPREADER BIN COLLECT. CHAIN cow. 5M DUST LOADING "9 TRUCK r- PATENIEDIIIII I 8 I974 SHEU 1 [If 6 RECEIVING sT. f CHAIN CONv. -Ie

MAT. TRANSF. /26

BELT COM. 32

WATER TANK I I 3 I REFUSE ROLLER WATER PUMP .FLOATER(WATER LEVEL) CHAIN CONv. SEPARAT. a 3 JETS SOLENOID OPERATE MAIN INTAKE B DRAIN 5| 76 40 I SHAKER sCREEN TAKE AWAY BELT CONV. IO

. I 93 BOARD a wow CHIPPER CLEANING BELT CONv. HOG BRUSH 96 CHIPS I CHAIN CONv. B I

CHAIN CONV. COLLECTING DRUM I03 CHIPS BELT CONv. MAG. PULLEY) /IO4 MAG CHUTE' & I BELT CONv. COLLECT. DRUM SHAKER SEPARATOR H5 I2I /IO7 l CHUTE a CHIPS CLEAN CHuTE BLOWER COLLECT. DRUM BELT CONv. CoARsE MAT FINE MAT.

(MAG. PULLEY) RECYCLE I I23 I I IIO CHuTE SPREADER BIN COLLECT. CHAIN cow. SAW DUST I LOADING 9 FIG TRUCK PATENTEDJun 18 m4 SHEET 2 0F 6 SHEET 3 [IF 6 PATENTEDJUN 16 m4 PATENTEDJun '8 m4 SHE u or 6 m di a. m

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PATENTEDJuu 18 m4 sum 5 UF 6 DEVICE AND PROCESS FOR RECLAIMING USED j WOOD The value of wood products, particularly old lumber, parts of wrecked buildings, boxes and the like, is presently of sufficient economic importance and worth to justify reclaiming the material. Hand labor for this purpose is prohibitive in cost. Furthermore, available used 1 material of this nature is often of widely variant wood sizes, shapes and conditions. Particularly, the wood is intermixed with all sorts of debris, such as concrete, brick, glass, metal, nails, cans, paper, fiber and comparable items. Mass handling of such used material in an economic and satisfactory fashion is a very difficult problem although a solution thereto is highly desirable from the standpoint of improved ecology and conservation of natural resources.

It is therefore an object of the invention to provide a machine and method for taking used wood material and its accompanying or associated debris in virtually any condition, i.e., as found after the demolition of buildings, the unpacking of goods and'the like and treating such used wood material'to afford a further usable and economic wood product. Usable by-products such as metal and the like may also be recovered.

Another object of the invention is to provide a device for effectively and economically reclaiming used wood from debris.

. A further object of the invention is to provide an effective method for reclaiming used wood from debris.

A further object of the invention is to provide a plant that will handlevery large quantities of used wood and debris with only a small amount of manual supervision and labor to afford an acceptable and reusable wood product.

Another object of the invention is in general to provide a way of treating for reuse used wood contaminated with debris.

Other objects, together with the foregoing, are attained in the embodiment of the invention described in the accompanying description and illustrated in the accompanying drawings, in which:

FIG. 1 is a diagram showing a flow chart of the machine operation and the process pursuant to the invention;

FIG. 2A is a plan of one portion of a device or'plant constructed to reclaim used wood material;

FIG. 2B is a plan of the remaining portion of the plant of FIG. 2A;

FIG. 3A is a side elevation of the portion'of the plant shown in FIG. 2A;

FIG. 3B is a side elevation of the remaining portion of the plant of FIG. 3A;

FIG. 4 is an elevation of one end of the plant shown in FIG. 2A;

FIG 5 is a side elevation to an enlarged scale of a water bath utilized in the plant and process, portions being broken away;

FIG. 6 is a plan of the water bath shown in FIG. 5, certain portions being broken away;

FIG. 7 is a fragmentary, enlarged cross-section, the plane of which is indicated by the line 7-7 of FIG. 3A; and

FIG. 8 is a fragmentary view showing some of the interior construction of the wood mill.

Whilethe used wood reclaiming device can be embodied and the process can be practiced in a large number of different ways, depending upon the particular requirements at a particular area, a protracted operation in the form illustrated herein has been conducted with considerable success. In this instance there are received wooden crates with banding straps, miscellaneous materials from demolished buildings, wood scraps from lumber yards and various other wood materials which have been used or have been discarded. Normally, these have no further economic utility and represent only a burden or waste. With such wood material there is usually intermixed all sorts of debris, particularly in connection with the substance of demo]- ished buildings. The debris may be in the nature of cement, plaster, miscellaneous plumbing, wire, bottles, paper, cloth, tar, roofing, bricks and comparable nonwood items.

The plant or device for carrying out the present reclaiming process is situated in an appropriate area on the ground 6 at a convenient point for access. There is a sunken receiving pit 7 having an open top 8 near a discharging area 9. Within the pit there is preferably provided downwardly converging side walls 11 and end walls 12 and also side guard rails 13 at the ground level. The arrangement is such that trucks or other carriers can utilize the area 9 to approach the rails 13 and dump their burden of used materials into the pit 7 by gravity. In one example, the pit is approximately 16 feet deep, about 60 feet long and about 20 feet wide.

Near the bottom of the pit and at the converging portion of the walls 11 and 12 thereis provided a receiving conveyor 16 conveniently trained over rollers 17 and 18. At least one of these is power driven, in the direction of the arrow 19. The conveyor 16 conveniently includes chains spanned by transverse rails or cleats 21 so that material dumped into the pit along its length is conveyed toward the left end thereof, as seen in FIGS. 2A and 3A. The end wall 12 at the left end is interrupted to provide an opening 22 at the end of the receiving conveyor 17. All the material on the conveyor 16, which usually is in the nature of wood, tramp metal and other debris, is dumped by gravity through the opening 22 onto a first conveyor 26.

The conveyor 26 is preferably a plain belt conveyor ascending at a gradual angle from a point near the bottom of the pit through an opening 27 in the end wall of the pit 7. The conveyor 26 rises to and above the level of the ground 6 in a trough 28, in effect a continuation of the pit. The first conveyor 26 extends to a satisfactory height above the level of the ground 6 and thereat discharges all of the conveyed material over the upper end of the conveyor 26 into a water bath 31. v

As shown to a large scale in FIGS. 5 and 6, the water bath is confined in a metal tank 32 having the customary bottom, sides and ends and left open at the top. Water is supplied to the tank through a supply line 33 from any appropriate source through a regulating valve 34 and enters the tank through a fitting 36. Water rises in the tank until it achieves an approximate level 37 which is especially regulated. Adjoining and communicating with the tank 32 is a quiet tank 38 disposed at one end of the tank 32 and containing a small volume of water at approximately the level 37. The tank 38 has a float 39 actuating an air valve 41 receiving air through a supply line 42. The air valve controls air flow through a line 43 to an air responsive controller 44 for the water valve 34. When the level 37 in the tank 32 and correspondingly in the quiet tank 38 falls and permits the float 39 to drop, the air valve 41 is correspondingly opened thus actuating the regulator 44 so that water flows in from the line 33 to the valve 34 and through the fitting 36 to add water to the bath 31. When the level is sufficiently high, the float 39 rises, cuts off the air and correspondingly cuts off the addition of water.

Periodic draining of water and sludge and refilling of the tank with fresh water can be accomplished through solenoid controlled valves 40.

Used wood and debris falling by gravity from the upper end of the first conveyor 26 (FIG. drops into the water bath 31. Much of that material is much heavier than water and so falls by gravity or settles out in the bath 31 and tends to fall toward the bottom of the tank 32. This debris includes not only heavy metal bodies, concrete, plaster, glass and items of that sort, but also sometimes may include extra heavy pieces of wood which might have become waterlogged, saturated with heavy fluid or encased with heavy material. All heavy components fall and tend to congregate on the bottom of the tank 32. Virtually all of the heavy, nonwood debris falls by gravity and separates from the floating wood in the water bath 31. Such heavy materials, as is particularly apparent from FIGS. 5 and 6, in dropping toward the bottom of the tank tend to lodge upon a conveyor belt 51. This has its upper run traveling in the direction of the arrow 52 in FIGS. 5 and 6 and ascends from a position near the bottom of the tank through an attached lateral trunk tank 53 to a level above that of the water bath level 37.

Particularly as shown in FIG. 2B, the debris is carried to a conventional shaker screen separator 58 or the like. Therein much of the entrained water is shaken off and drained and returns to the water tank through a duct 59. Debris separated from water or dewatered at the elevated shaker 58 falls by gravity into a suitable receptacle (not shown) for ultimate discharge.

This miscellaneous heavy material at the present time has little or no economic value. If it happens to contain a substantial portion of metal the shaker separator 58 or the upper pulley for the conveyor 51 can incorporate a magnetic separating means to segregate the metal from the remainder of the debris. In most instances, however, there is little or no material worth reclaiming in the wet debris on the belt 51. In this fashion much of the entering debris accompanying the used wood is immediately removed from the necessity for further handling and is taken away from the water bath and separately disposed of.

Material remaining in the water bath is largely flotsam disposed near the water level 37. It enters the tank 32 near one end. Means are provided for impelling such flotsam toward the other end of the tank. For that reason there is provided a circulating pump 66 (FIGS. Sand 6) driven by an electric motor 67 and having an intake line 68 connected to the trunk tank 53 at a convenient point below the water level therein. The pump 66 also has a discharge line 69 for pressure fluid which extends to the intake area of the tank 32. The line 69 is connected to a plurality of horizontal nozzles 71 mounted on a pipe manifold 72 and positioned to discharge horizontally away from the intake end of the tank at a height slightly below the water level 37.

When the pump 66 is operating water is removed from the trunk tank 53 and is projected with considerable velocity from the nozzles 71 so as to impel an upper level current of water to flow along the top of the tank from the right end toward the left end, as seen in FIG. 6. This water current tends to advance floating and nearly floating wood toward the left in the tank.

Should there be an excessive pile up of wood shapes near the top of the tank due to intermittent discharge from the first conveyor 26 or for other causes, the arriving floating material is spread and somewhat evened or dispersed by the operation of a roll 76 having a plurality of radial arms 77 thereon and mounted on a shaft 78 for rotation about a transverse horizontal axis just above the water level in the tank. The roll is driven by an electric motor 79 (FIG. 6) in a counter-clockwise direction, as seen in FIG. 5, to act as a spreader and separator so that the net effect of the operation of the water jets 71 and of the counter-rotating fingers 77 is to provide a reasonably uniform, slightly subaqueous flow of used wood, separated from the debris, toward the left in FIG. 6 and just above and onto a second conveyor 81. The upper run of this second conveyor 81 travels from right to left in FIG. 6 and emerges from the bath 31 at a gentle incline. The return run of the belt conveyor 81 reenters the tank through a trunk 82 adjoining the discharge end thereof.

The flotsam or supernatant or light, wood material on the upper run of the conveyor 81 continues in a generally upward direction from the water bath 31 to a wood mill 84 often referred to in the lumber and associated industries as a chipper hog. This is an enclosure in which there is a concave plate 86 with inwardly projecting teeth and a rotor 87 driven by an electric motor 88, the rotor having radially projecting teeth 89 intermeshing with the concave teeth 85. Wood shapes such as boards, beams, planks, panels and the like introduced into the wood mill 84 and worked upon by the rotor teeth 89 and concave teeth 85 emerge as wood splinters or slivers and finer particles. The wood received is, in effect, disintegrated or divided into relatively small particles of varying sizes. These particles for the most part fall by gravity into a receiving chamber 91.

Some of the particles, because of the wet nature of the material and because of their adhesive characteristics, tend to adhere to the conveyor belt 81 and even round the upper pulley 92 at the wood mill and tend to return on the lower run of the conveyor. Much of such material is not advantageously returned to the water bath and so there is in contact with the lower or return of the belt 81 a brush 93. This is propelled by a suitable electric motor and is effective to wipe off or scrape off any adherent material from the belt and to deposit such material in a trough 94. Near the bottom of the trough 94 is a transverse chain conveyor 96 extending laterally and conveying the received material away from the trough 94 to a collecting drum 95. Liquid and finely dissolved material brushed off by the brush and not large enough to be carried away by the conveyor 96 is taken back by a flume 97 returning to the water bath. To make sure that such returned material does not adhere to the flume but flows freely to the water bath, there is a jet spray from the end of a water pipe 98. This extends from the supply pipe 33 and washes the return material into the bath from which it is discharged ultimately on the cross conveyor belt 51. Alternatively, if

the material is extremely fine it is drained out with the periodic drainage of the water bath.

In some areas, there is available additional wood material which does not need to be treated in the water bath. For example, there may be clean wood shavings and the like or discard small wood from a lumber mill. This uncontaminated wood can be deposited from outside directly onto an auxiliary conveyor 102 leading into the upper portion of the mill 84 and discharged therefrom in disintegrated form. All 'of the finely divided material from the wood mill falls by gravity onto a chain conveyor 101. It is then transferred onto a conveyor 103 extending from a relatively low point near the ground and curved around a drum 104 at a rela tively high point.

At this location all of the material on the belt 103 is discharged by gravity. Material discharging from the end of the conveyor 103 and rounding the drum 104 may be subjected to magnetic attraction in the drum. If so, while the other, non-magnetic material and larger metal parts may discharge off the end of the conveyor, some small metallic particles adhere to the return run of the belt for a short distance due to the influence of the magnetized drum 104. Such metal may fall into a chute 105 leading into a suitable receptacle for small metallic particles. Falling material from the conveyor 103 is dropped onto a special belt conveyor 106 provided with means for establishing a magnetic field at the conveyor. The magnetic field causes any larger metallic items, such as wire bits, nails, screen shreds or the like to travel upwardly on the conveyor belt 106 and to discharge into a transverse trough 107 in turn leading to a discharge collector 108. Here the metallic material is released into a collecting drum or other suitable container so that any accompanying tramp metal is at this point finally removed from the treated wood. The recovered metal may be further processed by removal of the container 108. Material transferred to the belt 106 and of a non-magnetic nature, such as wood, falls eventually into a relatively large shaker and separator 111.

The separating device 111 includes a number of inclined plates or tables, as shown in FIG. 7. The upper plate has a series of relatively large openings 113 therein. An intermediate plate has a number of intermediate size openings 114 therein and the lowest plate has no openings therein. The device 111 includes a shaker or vibrator impelling the tables to shake or vibrate. Received materials are first directed through the openings 113 if their size is appropriate. Material which does not go through the openings 113 is discharged into a chute 115 onto the first conveyor for recycling. Material that does go through the openings 113 into the intermediate plate but not through the openings 114 travels over the lower edge of the intermediate table onto a conveyor 116 leading up to a loading and distributing conveyor 117 that extends generally horizontally at a substantial elevation. There are cleats 118 on the conveyor 117 to advance the conveyed material. The conveyor 116 discharges over its high end and deposits the conveyed material into a vehicle 119 stationed on the ground below. The operator of the vehicle 119 drives it forward slowly as the conveyor 117 operates and in that fashion gets a substantially uniform lading of his vehicle. This lading is the finished, fragmented, used wood of relatively large size. To make sure that no tramp metal is released into the truck 119, the upper pulley for the conveyor 116 may be magnetic and may discharge into a metal collection chute 110.

Material which passes through the table openings 114 and is of smaller size then is discharged from the separator 111 and sucked into a duct 120 leading through a blower 121 and discharged by the blower through a pipe 122 into a storage bin 123. The result of this operation is that fine particles such as sawdust or comparably sized material is well separated from the larger material going to thetruck 119 and is carried ultimately to storage. In one instance, the larger materials carried away by the truck 119 go to a paper manufactory for pulping, whereas the smaller particles that are carried to storage 123 are periodically removed therefrom in order to be further processed as fine particle wood.

In this fashion, there is provided a mechanism and method for taking at random miscellaneous and heterogeneous used wood of various shapes, sizes and kinds accompanied by debris and contaminating matter of all sorts and ultimately supplying separate wood particles of relatively large size useful in the manufacture of paper pulp and of relatively small size utilized in connection with other products. The final wood products are devoid of metal, separated and sold for reuse, and devoid of cement, sand and glass, and other materials 7 of that nature. These have no present economic use but are segregated and can be taken away from the site as a separate entity.

The method employed includes taking in the initial used wood and debris, separating the wood and some debris in the water bath, then grinding or milling the wood into myriad small particles, dewatering it, separating any entrained tramp metal from the wood particles for separate disposition and finally sizing the treated wood particles into those of larger size and those of smaller size and taking the separated wood sizes to other sites for further utilization.

What is claimed is:

1. A used wood reclaiming device comprising:

a. means for receiving material including miscellaneous wood pieces and accompanying debris;

b. a water tank;

c. a first conveyor for transferring said material to said water tank;

d. a wood mill for reducing wood pieces to particles;

e. a second conveyor for carrying floating material from said tank to said mill;

f. a third conveyor for carrying sinking material from said tank;

g. means for separating the reduced wood pieces emergent from said mill at least into a first portion of one size particles and a second portion of another size particles;

h. a fourth conveyor for carrying said reduced wood pieces from said wood mill to said separating means;

i. means associated with said fourth conveyor for removing magnetically responsive metal from said reduced wood pieces;

j. a loading means;

k. means for carrying said first portion from said separating means-to said loading means;

1. a storage means; and,

m. means for carrying said second portion to said storage means.

6. A device as in claim 1 in which said first conveyor is a belt having an upper run and a lower run and including means for removing adhering material from said lower run.

7. A used wood reclaiming process comprising subjecting received material containing wood pieces and debris to a water bath in one area in which one part of said material floats and another part of said material sinks, removing said one part from said water bath area, then comminuting said one part, and then sizing said one part at least into large pieces and small pieces.

8. A process as in claim 7 including the step of re moving said other part from said water bath area.

9. A process as in claim 7 including the step of subjecting said one part to a magnetic field.

Claims (8)

1. 2. A device as in claim 1 including means for urging floating material in said tank toward said second conveyor.
2. 3. A device as in claim 1 including means for maintaining a predetermined level of water in said tank.
3. 4. A device as in claim 1 including means in said loading means for distributing said first portion over a predetermined area.
4. 5. A device as in claim 1 including means associated with said separating means for directing oversize material from said separating means to said first conveyor.
5. 6. A device as in claim 1 in which said first conveyor is a belt having an upper run and a lower run and including means for removing adhering material from said lower run.
6. 7. A used wood reclaiming process comprising subjecting received material containing wood pieces and debris to a water bath in one area in which one part of said material floats and another part of said material sinks, removing said one part from said water bath area, then comminuting said one part, and then sizing said one part at least into large pieces and small pieces.
7. 8. A process as in claim 7 including the step of removing said other part from said water bath area.
8. 9. A process as in claim 7 including the step of subjecting said one part to a magnetic field.

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