Anti-polluting Waste Collector For A Burn Table

Abstract

An anti-polluting waste collector for a burn table, adapted for supporting a workpiece beneath a flame cutting machine, includes an open tank containing a liquid maintained at a predetermined level therein and a grating disposed across the tank opening. An air chamber is selectively pressurized to provide a pressure head for normally maintaining the predetermined liquid level above the grating and to lower such level below the grating for convenient removal of waste material trapped thereon.

Description

BACKGROUND OF THE INVENTION

Conventional flame cutting machines have multiple torches for cutting steel plates into desired shapes. The torches are mounted to transverse the steel plates and the cutting operation results in a considerable amount of cutting waste in the form of relatively small iron oxide particles and solidified molten metal. The small oxide particles are in the form of sparks, some of which tend to become air borne causing air pollution which is irritating to the operators and other persons working in the area. The molten metal drops to the floor where it cools and forms slag with the oxides, which when hardened, frequently must be broken up with air hammers or chisels in order to effect its removal. Also, a plurality of smaller scrap pieces are usually cut from the steel plates and fall to the floor to become part of the slag accumulation and cannot be reclaimed economically for subsequent use. Reclamation of the slag reduces its value to about one-half the value of the salvagable scrap pieces cut from the steel plates due to the presence of oxides therein.

Various methods have been employed for reducing the air pollution created by such flame cutting machines. For example, U.S. Pat. No. 3,486,744, assigned to the assignee of the present application, provides a continuous stream of water over an inclined trough disposed beneath the cutting torches. A pump is employed to recirculate the water which is contaminated by entrapped oxide particles. The abrasive nature of the oxide particles causes undue wear to the pump which necessitates its frequent replacement.

SUMMARY AND OBJECTS OF THE INVENTION

Accordingly, it is an object of this invention to provide an improved, anti-polluting waste collector for a burn table of a flame cutting machine.

Another object of this invention is to provide an improved waste collector for a burn table having a tank containing a liquid which entraps oxide particles and molten metal waste to reduce the air pollution caused by the oxide particles and to reduce the maintenance cost incurred from removing the slag formed by the molten metal waste.

Another object of this invention is to provide a waste collector for a burn table having a grating mounted directly below cutting torches for separating salvageable waste material from the oxide particles and slag.

Another object of this invention is to provide a waste collector for a burn table having a gas-pressurized chamber communicating with the liquid containing tank to provide a pressure head for normally maintaining a predetermined liquid level above the grating during operation of the burn table and for selectively lowering such level below the grating to enable salvageable waste material to be conveniently removed therefrom.

Other objects and advantages of the present invention will become more readily apparent upon reference to the accompanying drawings and the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a transverse vertical section taken through a waste collector embodying the principles of the present invention, associated with a flame cutting machine shown in an operating condition, containing a predetermined level of liquid therein;

FIG. 2 is a transverse vertical section similar to FIG. 1, but showing the flame cutting machine in a non-operating condition with the liquid level of the waste collector disposed below the level shown in FIG. 1; and

FIG. 3 is a longitudinal vertical section taken centrally through the waste collector in the condition shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, a waste collector 10 embodying the present invention is positioned beneath a conventional flame cutting machine 11. The cutting machine comprises a plurality of downwardly directed cutting torches 12 mounted on a beam 13 extending over the waste collector. The cutting machine is supported by a plurality of rollers, one of which is shown at 14, riding on a support structure 15 disposed on a support pad 16 adjacent to the waste collector for traversement of the torches along the burn table.

The waste collector includes a tank 17 having an upper portion 18, a lower portion 19 and a settling pit 21. The upper portion is disposed above support pad 16 and includes a pair of spaced side plates 22 and a pair of spaced end plates 23 individually secured to the ends of the side plates. The side plates and end plates are L-shaped and have a horizontal leg 24 directed inwardly to form a ledge which rests on the support pad.

A grating 26 has its outer edges 27 secured to legs 24 of the side plates and end plates. The grating is of conventional construction having a plurality of openings 28 therein of a size sufficient to retain the waste material of a size worth salvaging. Upper portion 18 of the tank includes a burn table 29 formed from a plurality of spaced support members 31, disposed above grating 26 to extend transversely between and in secured relationship with side plates 22. A plurality of adapters 32 are carried by each support member 31 to provide support means along with a non-ferrous rod 33 which supports a workpiece 34 to be cut, such as a steel plate or the like.

Referring to FIG. 1, lower portion 19 of the tank includes a pair of spaced vertical sidewalls 36, each having its upper edge joined, as by welding or the like, to a leg 24 of a respective side plate 22 (FIG. 1). Each sidewall 36 has a slanted section 37 sloping inwardly toward the opposite sidewall and a lower edge 38. Referring to FIG. 3, a pair of end walls 39 and 41 are disposed between sidewalls 36 and each has its upper edge secured to a leg 24 of a respective end plate 23. The end walls slope downwardly and inwardly from the legs in converging relationship. A lower edge 42 of end wall 39 and a lower portion 43 of end wall 41 cooperate with edges 38 of sidewalls (FIG. 1) to define an opening 44 at the bottom of the tank. Lower portion 43 extends below opening 44 and into settling pit 21.

Lower portion 19 of the tank includes a pair of oppositely spaced panels 46 secured between end walls 39 and 41. Each of the panels has an upper edge secured to the upper edge of its associated sidewall. The panels slope downwardly and inwardly in parallel relation to sections 37 of sidewalls 36 to form a pair of spaced air-over-liquid chambers 47, comprising liquid level control means, between the panels and the sidewalls. The panels each have a lower vertical section 48 spaced from the sidewalls to afford an opening 49 therebetween for communicating chambers 47 with the lower portion of the tank.

The liquid level control means further comprises a source of gas pressure, such as in air compressor 51, connected to chambers 47 by way of a conduit 52 having a conventional manual control valve 53 disposed therein. The control valve has a first position whereby pressurized air from the compressor is directed to the chambers, a second position for trapping the air within the chambers and a third position for which exhausting the air from the chambers is achieved.

Settling pit 21 is disposed below lower portion 19 of the tank and is in communication therewith through opening 44. The settling pit is formed at one end of the tank and includes a trough 54 secured to the outside of end wall 39 and end plate 23. An inclined endless conveyor 56 is disposed in the trough with the lower end thereof extending below opening 44 and lower portion 43 of end wall 41.

As fully explained below, tank 17 will contain a constant or fixed volume of liquid, such as water, maintained at a predetermined lower level 57, below grating 26, when the flame cutting machine is not operating (FIGS. 2 and 3). During operation of the flame cutting machine, the liquid is raised and maintained at a predetermined upper level 58, above the grating (FIG. 1).

OPERATION

While the operation of the present invention is believed clearly apparent from the foregoing description, further amplification will subsequently be made in the following brief summary of such operation. During the cutting operation (FIG. 1), the liquid is maintained at its predetermined upper level 58, above grating 26, by a pressure head of air trapped within chambers 47. Oxide particles produced by the flame cutting operation are propelled downwardly by the flame and into the liquid where they are entrapped and are permitted gradually to settle to the bottom of the tank. Molten metal produced by the cutting operation also falls downwardly from workpiece 34 and into the liquid where it solidifies and is permitted to sink along with the oxide particles. Small salvageable waste pieces cut from the workpiece drop into the liquid and are retained on the grating.

Sloping panels 46 and end walls 39 and 41 direct the oxide particles and solidified waste toward opening 44 at the bottom of the tank where they are directed by lower portion 43 of end wall 41 onto conveyor 56 which carries them out of the tank and deposits them into a suitable container, not shown. To retrieve the salvageable waste pieces from grating 26, control valve 53 is selectively adjusted to exhaust the air from chambers 47 to allow liquid in the tank to enter the chambers. Lowering of the water level to lower level 57, below the grating, permits the operator to walk on the grating to retrieve the salvageable pieces.

In order to pre-condition waste collector 10 for subsequent operation of flame cutting machine 11, control valve 53 is selectively adjusted to direct pressurized air from compressor 51 to chambers 47. The resulting air pressure head therein forces the water from the chambers, causing the water level in the tank 17 to rise to its upper level 58, above the grating. The valve is then selectively adjusted to trap the air in the chamber to maintain the water level in the tank at such predetermined, upper level.

In view of the foregoing, it is readily apparent that the structure of the present invention provides an improved waste collector which substantially reduces air pollution normally caused by the oxide particles resulting from the cutting operation. The waste collector further reduces maintenance costs normally incurred when slag is removed from cutting machines of this type. It is also significant that the waste collector successfully separates salvageable waste pieces from the slag to permit their reclamation as a higher grade of scrap in comparison to when they are combined with the slag. The tank contains a constant and substantially static volume of liquid, the level of which can be expeditiously adjusted by the selectively air-pressurizing chambers 47 to thereby eliminate the need for expensive pumps and attendant moving parts. The only additional liquid required during operation constitutes periodic replacement of minimal amounts lost by evaporation.

While the invention has been described and shown with particular reference to the preferred embodiments, it will be apparent that variations might be possible that would fall within the scope of the present invention which is not intended to be limited, except as defined in the following claims. For example, it should be noted that chambers 47 could be placed exteriorly of tank 17. However, the illustrated embodiment constitutes the preferred one primarily due to its compactness and economical make-up.

Claims

What is claimed is:

1. A waste collector adapted for supporting a workpiece beneath a flame cutting machine and to receive waste material therefrom comprising;

a tank having an open top and containing a liquid normally maintained at a predetermined upper level;

liquid level control means connected to said tank for normally maintaining said liquid at said upper level and for selectively lowering and maintaining the liquid level at a predetermined lower level disposed vertically below said upper level; and

a horizontally disposed grating means attached to said tank to extend across the open top thereof and disposed vertically below said upper level and vertically above said lower level.

2. The invention of claim 1 further comprising support means mounted vertically above and closely adjacent to said grating means for supporting a workpiece thereon and a flame cutting machine mounted vertically above said support means.

3. The waste collector of claim 1 wherein said liquid level control means includes means forming at least one expansible chamber normally containing a pressurized gas therein, said chamber communicating with said tank to normally provide a pressure head sufficient to support and maintain said liquid at said predetermined upper level until the gas pressure in said chamber is reduced to permit a portion of the liquid to drain from the tank and into the chamber to lower the liquid to said lower level.

4. The waste collector of claim 3 wherein said liquid level control means further comprises a source of gas under pressure and control valve means for selectively communicating said gas to said chamber.

5. The waste collector of claim 3 wherein said chamber is integrally formed within said tank.

6. The waste collector of claim 1 wherein said grating means comprises a grate having a plurality of openings formed therethrough, said openings being sized to allow the passage of fine waste material therethrough while retaining larger salvageable material thereon.

7. A waste collector for use with a flame cutting machine to receive and retain waste material therefrom comprising,

a tank having an open top portion and a lower portion containing a substantially constant volume of liquid, means forming a burn table across said top of the tank for supporting a workpiece beneath the flame cutting machine,

grating means in predetermined spaced relation below the burn table for collecting and retaining a portion of such waste material thereon,

a downwardly directed baffle plate disposed within said tank forming an air-liquid chamber having a bottom opening into the tank, and means to selectively provide a pressure head within the chamber sufficient to elevate and support said liquid within the tank at a predetermined upper level until the pressure in the chamber is reduced to enable a portion of said constant volume of liquid to drain from the tank into the chamber in order to lower the liquid level in the tank from said upper level to a predetermined lower level below the grating.

8. The waste collector of claim 7 wherein said tank includes downwardly sloping sidewalls converging toward said lower portion of the tank, and a pair of said baffles individually disposed in spaced and substantially parallel relation to said sidewalls to form a pair of said chambers within the tank with said baffles terminating in lower ends spaced from said lower portion of the tank to permit the transfer of said liquid between the chambers and the tank.

9. The waste collector of claim 8 wherein said tank includes a pair of end walls and an opening at said lower portion thereof, a trough adjacent to one end wall forming a settling pit below said opening, a conveyor disposed in said trough and extending below said opening, and the end wall opposite to said one end wall having an extension extending below the opening to afford a waste material guide means to direct the waste material gravitating through said opening onto the conveyor to elevate the waste material from said settling pit.

10. A waste collector adapted for supporting a workpiece beneath a flame cutting machine and to receive waste material therefrom comprising:

a tank having an open top and containing a liquid normally maintained at a predetermined upper level; and

liquid level control means connected to said tank for normally maintaining said liquid at said upper level and for selectively lowering and maintaining the liquid level at a predetermined lower level disposed vertically below said upper level, said liquid level control means including

means forming at least one expansible chamber normally containing a pressurized gas therein, said chamber communicating with said tank to normally provide a pressure head sufficient to support and maintain said liquid at said predetermined upper level until the gas pressure in said chamber is reduced to permit a portion of the liquid to drain from the tank and into the chamber to lower the liquid to said lower level.

11. The waste collector of claim 10 wherein said liquid level control means further comprises a source of gas under pressure and control valve means for selectively communicating said gas to said chamber.

12. The waste collector of claim 10 wherein said chamber is integrally formed within said tank.