US3450529A - Metal briquette compacting method and machine therefor - Google Patents

Description

June 17,1969 a McDONALD 3,450,529

METAL BRIQUETTE COMPACTING METHOD AND MACHINE THEREFOR Filed March 19, 1968 INVENT OR WARD D. MucDONALD W. H wfw ATTORNEY United States Patent US. Cl. 75211 9 Claims ABSTRACT OF THE DISCLOSURE This disclosures relates to a process and apparatus for making metal briquettes for foundry operations. The briquettes are made, for example, from oily metal particles, such as metal turnings, which are fed to a furnace to burn the oil therefrom. In the furnace, the particles are heated to a high temperature of, for example, 1200 to 1400 F. The heated and de-oiled particles are passed directly to a hopper which feeds the briquetting mechanism. The temperature of the de-oiled particles are sensed and is maintained within a predetermined range for briquetting by adjusting the feed to the furnace in accordance with the sensed temperature. The amount of de-oiled particles in the feed hopper is controlled to prevent overflow of the feed hopper and to maintain the density of the briquettes by sensing the level of de-oiled particles in the feed hopper and adjusting the speed of the briquetting rolls accordingly to maintain the proper level.

This invention relates to processing of metallic particulate materials. In one of its aspects it relates to a sintering operation for compacting de-oiled metal particles, such as turnings, into briquettes where the de-oiled particles are fed at a high temperature to a hopper and passed from the hopper through briquetting rolls, wherein the level of particles in the hopper is sensed and the speed of the briquetting rolls is adjusted accordingly to maintain the level of particles within the hopper such that the particles do not overflow the hopper and such that suflicient particles are present in the hopper to adequately feed the briquetting rolls to make high density metal briquettes.

In another of its aspects, the invention relates to a sintering operation wherein oily metallic particles are fed to a de-oiling zone, the particles are heated to a de-oiling temperature in the presence of oxygen, and are then fed directly to a briquetting zone wherein the particles are compacted to high density briquettes, wherein the temperature of the de-oiled particles is sensed between the de-oiling zone and the briquetting zone, and the amount of oily particles fed to the de-oiling zone is adjusted to maintain the temperature of the de-oiled particles suitable for hot briquetting.

In still another of its aspects, the invention relates to an apparatus for compacting de-oiled metallic particles such as turnings comprising: compacting rolls which form metallic briquettes when particulate metallic material is fed between the rolls as they turn, a feed hopper means aligned with the rolls to feed hot de-oiled turnings between the rolls for compacting, means to rotate the compacting rolls, and means to vary the speed of the rolls so that the amount of de-oiled metallic particulate material in the hopper can be maintained at a predetermined level, such that suflicient material is fed to the rolls to produce a dense briquette and so that the amount of hot particulate material in the feed hopper will be insuflicient to overflow the hopper.

In still another of its aspects, the invention relates to a de-oiling apparatus wherein oily metallic material is passed to a de-oiling means which is adapted to burn the oil from the metallic material while heating the metallic material to a high temperature, means are provided to sense the temperature of the de-oiled material passing from the de-oiling means, and means are provided to regulate the amount of oily material fed to the de-oiling means in accordance with the sensed temperature such that the temperature of the metallic effluent from the deoiling means is maintained within a predetermined tem perature range.

Murphy, in Iron Age, June 22, 1967, pp. 65-67, discloses a new process for making dense metal briquettes wherein oily iron borings are heated in a de-oiling furnace and passed directly to compacting rolls.

One requirement of this process is that the temperature of the heated metallic material fed to the rolls must be in the range of 1000 to 1400 F., preferably in the range of 1200 to 1400 F. De-oiling furnaces using an excess of oxygen and in some cases fuel, generally produce hot de-oiled metallic material in the range of 1200 to 1400 F. However, the oil content of the charge varies, and therefore, the temperature of the de-oiled borings passing out of the de-oiling furnace will fluctuate. Sometimes, the temperature of the eflluent boring from the de-oiling furnace will exceed 1400 F. and in some cases be less than 1000 F.

I have now discovered that the temperature of metallic material fed to the compacting rolls can be controlled by sensing the temperature of the de-oiled borings as they pass from the de-oiling furnace and, according, adjusting the speed of the material to the furnace to maintain the temperature within the predetermined range.

When the briquetting rolls are fed from the eflluent from the de-oiling furnace, the hopper load tends to fluctuate due to the varying amounts of de-oiled material fed to the compacting rolls. When the hopper gets too full, the de-oiling furnace must be shut down to prevent the hopper from overflowing and in some cases to prevent sintering or fusing together of the de-oiled borings in the feed hopper. When the level of de-oiled borings becomes too low, for example, below about 500 lbs., the density of the briquettes drops appreciably.

I have now discovered that the density of the briquettes can be maintained at a high level without overflow or sintering in the hopper by sensing the level of metallic material in the hopper and, accordingly, adjusting the speed of the rolls to maintain the proper range of material within the hopper.

By various aspects of this invention one or more of the following, or other, objects can be obtained.

It is an object of this invention to provide an improved process and apparatus for producing high density metallic briquettes.

It is a further object of this invention to provide an integrated process and apparatus for producing high density metal briquettes from oily metal borings wherein variation in temperature of feed to the briquetting rolls is minimized.

It is a further object of this invention to provide a method and apparatus for producing high density metal briquettes wherein overflow of and sintering in the feed hopper to the compacting rolls is eliminated.

It is yet another object of this invention to provide a process and apparatus for producing high density metal briquettes wherein the propensity to produce low density metal briquettes due to little metallic material in the feed hopper is eliminated.

Other aspects, objects, and the several advantages of this invention are apparent to one skilled in the art from a study of this disclosure, the drawings, and the appended claims.

According to the invention, there is provided an operation for compacting de-oiled metal particles wherein deoiled particles such as iron turnings and borings are fed to a feed hopper and passed from the hopper through compacting rolls. The level of the hot metal material within the feed hopper is sensed and the speed of the compacting rolls is adjusted accordingly to maintain the level within the feed hopper at a predetermined range such that sufficient turnings are maintained in the hopper to adequately feed the briquetting rolls for making high density briquettes and to eliminate overflow of the material in the feed hopper.

Further according to the invention, the compacting rolls are fed by the effluent from a de-oiling furnace in which the temperature of the effluent from a de-oiling furnace is sensed and the amount of material fed to the de-oiling furnace is controlled so as to maintain the temperature of the de-oiled turnings Within a range suitable for briquetting.

With the operation of the manual controls can be employed for adjusting the speed of the compacting rolls responsive to the level of material in the hopper or the speed of the rolls can be adjusted manually.

Similarly, the control of the feeder device for the deoiling furnace can be done automatically or manually responsive to the sensed temperature of the de-oiled turnings.

The invention will now be described with reference to the accompanying drawing in which a schematic embodiment of the invention is shown.

Referring now to the drawing, oily iron turnings or borings 2 are loaded into hopper 4 for processing. The oily iron turnings pass from the lower portion of the hopper 4 onto a conveyor 6 driven by motor 7, and are passed to a bucket conveyor 8 driven by a motor 9. The oily iron turnings in the bucket conveyor are dumped into a feed trough 10 through which the turnings pass to a rotary de-oiling furnace 12. The de-oiling furnace 12 is of conventional design and is described more fully in my US. Patent Nos. 2,852,418 and 2,925,821. In the deoiling furnace, the iron turnings are heated in the presence of oxygen to a temperature of about l200 to 1300 F.

After the turnings have been de-oiled, they pass from the exit end of rotary furnace 12 onto chute 14 and into feed hopper 16.

The de-oiled turnings 26 pass from feed hopper 16 through throat 18 and then through briquetting rolls 20 which compress and compact the de-oiled turnings into briquettes 28. Each roll 20 has a plurality of pockets which are aligned with pockets on the adjacent roll so that de-oiled turnings falling between the rolls 20 will be compacted in the pockets to form briquettes. A screen vibratory conveyor 22 latches the briquettes and immediately passes them into a quench tank containing water 32. The elapse of time between the removal of the briquettes 28 from the briquetting rolls 20 and the quenching in the water tank preferably is the range of 30 seconds to 2 minutes.

A small percentage of the turnings passing through the briquetting rolls are not pressed into briquettes. These turnings will drop through the screen vibratory conveyor 22 onto a collector 24 and will be directed by a chute 34 to a suitable conveyor 36 to be recycled to the vibratory conveyor 6.

For a proper briquetting operation, the de-oiled turnings must have a temperature of 1200 to 1300 F. The de-oiling process in the rotary furnace generally heats the turnings during the de-oiling process so that the turnings at the exit end of the furnace are at a temperature in the range of 1500 F. depending on the amount of oil on the original turnings and the amount of turnings fed into the furnace. According to one embodiment of the invention, the temperature of the turnings at the exit end invention, automatic or of the furnace 12 is maintained at about 1200 to 1300 F. by sensing the temperature at the exit end of the furnace and controlling the speed at which the oily turnings are fed to the furnace to maintain the predetermined temperature. To this end, a temperature sensing probe 38 senses the temperature of the de-oiled turnings as they leave the furnace 12 and transmits this information to a temperature recorder controller 40 which, in turn, controls a speed controller 42 for motor 7. Accordingly, if the temperature of the de-oiled turnings coming out of the furnace 12 is too high, the temperature recorder controller 40 will cause speed controller 42 to reduce the speed of motor 7 to cause fewer oily turnings to be fed to furnace 12. Conversely, if the temperature of the deoiled turnings is too low, the temperature recorder controller 40 will cause the speed controller 42 to speed motor 9 to increase the amount of de-oiled turnings fed to the rotary furnace 12.

According to another embodiment of the invention, the de-oiled turnings 26 are maintained at a predetermined level in throat 18 of the feed hopper 16. The deoiled turnings are at a temperature in the range of 1200 to 1300 F. as they pass from the rotary furnace 12. If too many of these de-oiled turnings at 1200 to 1300 F. accumulate in the feed hopper 16, the de-oiling operation will have to be stopped to prevent overflow of the turnings in the feed hopper 16 conversely if insufficient de-oiled turnings are in the throat 18 an insufficient amount of these turnings will be passed to briquetting rolls 20 and the resulting briquettes will have a low density.

To this end, a probe 44 and a probe 46 are provided at different levels of throat 18 of feed hopper 16. These probes are used to indicate the level of turnings within the feed hopper 18. Suitable probes include Bindicator probes manufactured by the Bindicator Co. of Detroit. The level of turnings in throat 18 of feed hopper 16 is maintained at a predetermined level, or between certain predetermined points in the feed hopper, by sensing the level of the de-oiled turnings 26 in throat 18 and, accordingly, controlling the speed at which the briquetting rolls are turned. Thus, if the level of de-oiled turnings 26 in throat 18 rises to or above probe 44, the speed of the briquetting rolls will be increased so as to decrease this level of de-oiled turnings. Conversely, in the event that the level of de-oiled turnings within the throat 18 falls to or below probe 46, the speed at which the briquetting rolls 20 are turned will be reduced to increase the level within the throat.

To this end, a level controller 48 can be attached to probe 44 and 46. The level controller can control the speed controller 50 attached to motor 21 which drives the briquetting rolls 20.

Thus the invention involves, in a more specific embodiment, maintaining the temperature of the de-oiled iron turnings in the feed hopper at about 1200" to 1300 F. and maintaining the level within throat 18 at a predetermined level to, on the one hand, maintain at least a minimum value for the density of the briquettes and, on the other hand, to prevent the de-oiled turnings from sintering and fusing together within the feed hopper.

The metallic materials can be compacted to make briquettes or similar compressed articles from such materials as iron and steel turnings, copper, aluminum turnings and other particulate metallic material. As used throughout this specification, the term briquette is intended to signify all forms of compressed metal such as sheets, rectangles, etc., as well as the well-known cylindrical shape.

The process and apparatus is especially suitable for compacting particulate iron materials such as results from oily iron borings and turnings.

Generally, for iron borings, the weight of the borings in the feed hopper above the rolls will be at least 500 lbs.

Reasonable variation and modification are possible within the scope of the foregoing disclosure, the drawings, and the appended claims without departing from the spirit of the invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a sintering operation for compacting de-oiled metal particles at elevated temperatures into high density briquettes wherein feeding means are provided to feed the de-oiled particles to a compacting means, the improvement which comprises sensing the amount of the de-oiled particles in said feeding means being fed to said compacting means, and adjusting the speed of said compacting means to maintain a predetermined amount of particles being fed to said compacting means such that said particles do not overflow said feeding means and such that sufficient amount of particles are maintained in said feeding means to adequately feed said compacting means to make high density briquettes.

2. A sintering operation according to claim 1 wherein said metal particles are iron turnings and the temperature of said de-oiled turnings are in the range of 1000 to 1400 F.

3. A sintering operation according to claim 2 wherein said feeding means is a feed hopper and the weight of said metallic particles in said hopper above said compacting means is at least 500 lbs.

4. A sintering operation according to claim 1 wherein said feeding means receives said particles as the effluent from a de-oiling zone.

5. A sintering operation according to claim 4 wherein said de-oiled metallic particles are heated to a temperature in the range of 1200 to 1400 F. in said de-oiling zone.

6. In a sintering operation wherein oily metallic particles are fed to a dc-oiling zone, said oily metallic particles are heated to a de-oiling temperature in the presence of oxygen to burn oil from said metallic particles, the hot de-oiled metallic particles are passed to a hot briquetting zone wherein said hot de-oiled metallic particles are compacted to high density articles, the improvement which comprises: sensing the temperature of said de-oiled turnings between said de-oiling zone and said briquetting zone and adjusting the speed of said oily metallic particles to said de-oiling zone to maintain the temperature of said de-oiled metallic particles at a suitable temperature for said compacting step.

7. A sintering operation according to claim 6 wherein said de-oiled metallic particles are iron borings and are maintained in the range of 1000 to 1400 F.

8. A sintering operation according to claim 6 wherein said de-oiled metallic particles are iron borings and the temperature of said de-oiled metallic particles is maintained in the range of 1200 to 1400 F.

9. A sintering operation according to claim 6 wherein said de-oiled metallic particles are passed from said deoiling zone to a hopper prior to passing to' said briquetting zone, the level of said de-oiled metallic particles in said hopper is sensed and the rate at which said de-oiled metallic particles are compacted is adjusted to maintain the level in said hopper such that said metallic particles do not overflow said hopper, and to maintain the level such that sufiicient de-oiled metallic particles are present so that a high density sintered product is produced.

References Cited UNITED STATES PATENTS 2,814,564 11/1957 Hayden 75211 3,298,060 1/1967 Michalak 18-9 3,328,843 7/1967 Murphy 189 X 3,366,717 1/1968 Rohaus 264--40 BENJAMIN R. PADGETT, Primary Examiner.

ARTHUR I. STEINER, Assistant Examiner.

US. Cl. X.R.

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