US1893505A - Apparatus for collecting and conveying dusts - Google Patents

Description

Jan. 10, 1933. P. P. NUNGESSER APPARATUS FOR COLLECTING AND CONVEYING DUS'IS Filed Feb. 6, 1931 2 Sheets-Sheet INVENTOR ATTORNEY Jan. 10, 1933. P. P. NUNGESSER APPARATUS FOR COLLECTING AND CONVEYING DUSTS Filed Feb. 6. 1951 2 Sheets-Sheet HIL/P P- NUNEES'EER lNVENTOR YEY ATTORNEY Patented Jan. 10, 1933 PATENT OFFICE PHILIP P. NU NGESSER, F CLEVELAND HEIGHTS, OHIO APPARATUS FOR COLLECTING AND CONVEYING DUSTS Application filed February 6, 1931. Serial No. 513,941.

My invention relates to a method and apparatus for producing and collecting comminuted materials, especially bronze powders. To exemplify, in the manufacture of finely-divided aluminum or powdered aluminum the practice is to reduce pieces of aluminum to a flaky condition and then to a fine powder by repeated stamping operations within a closed mortar or vessel. Stamping machines or mills of that type are'customarily operated in banks or batteries, the coarser product of one machine being transferred to lighter machines to produce a more finelydivided product or powder. One problem of the manufacturer of such powders is to make and collect the finely-divided product without having it escape and accumulate to the detriment and danger of the operators and other persons in the rooms and vinicity where the work is being carried on. In that connection it is well known that the hazards of fire and explosion alone are very great. The reduction of the material toa desired fineness is also a time-consuming operation requiring skillful attention for its proper execution and the production of a good product. Now, my object in general is toprovide a safe and eifective method and apparatus which will speed up production, promote uniformity in the final product, and reduce or eliminate the hazards of fire and explosion in the stamping and collecting operations. To

achieve these objects, and incidently others,-

I have devised the present metl 0d and apparatus whereby the stamping of metallic pieces, such as aluminum pieces, may be effected under a reduced atmospheric pressure or a partial vacuum, maintained at a predetermined degree of intensity in the stamp- 40 ing machine or vessel, say by creating a constant suction or exhaust of approximately one and one-half inches (water gauge) ,at the outlet of an auxiliary exhaust chamber for the machine or vessel. At this relatively low suction value only the very lightest floating particles in the stamping machine will be withdrawn continuously and expeditiously during stamping operations. Thus, as rapidly as the metal is reduced and burnlshed to a desired uniform fineness and luster it is immediately separated from the other particles in suspension and under agitation in the stamping mill, and then after a short travel under a low degree of suction it is conveyed by air under pressure and at high velocity through closed conduits until finally deposited in air filters or separators and suitable collecting containers or receptacles, all as hereinafter shown and described in detail and more concisely set forth in the claims. In the accompanying drawings, Figs. 1 and 2 are plan and side views, respectively, on a reduced scale and in part diagrammatic, of an apparatus for producing and collecting powdered materials, according to my invention. Fig. 3 is a sectional view of one of the ejectors and a stamping machine connected operatively together, and Fig. 4 is a sectional view of the graduated exhaust connection for the stamping machine.

In the manufacture of metallic powder, particularly lustrous aluminum powder, by stamping operations, the pressure and burnishing action of stamping gives such powder its desired characteristics, appearance and value. Such operations can also be unduly prolonged with objectionable results, using the stamping machines orbatteries of such machines as commonly. These machines vary in design and construction, but in general,

embody steel drop hammers operating within a closed vessel.

Machine A shown in the drawings is merely an exemplification of one machine which may be used, it being understood that such machines also include cam or pneumatic means to operate the hammers.

When banks or batteries of such machines are operated in a room or building, as customarily, the fine dust or powder escapes and accumulates to such an objectionable and unsafe degree that extreme caution must be exercised to prevent fire and explosion, due

to heating of the machinery or exposure to within the machine or stamping vessel itself' so that the dust or powder cannot escape 5 into the room but only can be withdrawn slowly and by degrees from the vessel and thence conveyed by air pressure through conduits or pipes to a remote point outside of the stamping room or building where the air may be filtered and the powder collected in safety.

In Figs. 1- and 2, I show a walled enclosure or building B in which a number of stamping machines A, or batteries of such machines, are arranged in a row at opposite sides of the enclosure beneath overhead'air pipes C and powder discharge conduits D, respectively, which extend parallelly the length of the building. Preferably, air line C is composed of a series of pipe sections 2 united together by flanged joints, the sections beingreduced in diameter successively, in the direction of flow to provide an elongated airdistributing manifold of gradually decreasing size having an intake branch 3 at its larger end through which air under pressure may be supplied by a fan or blower .(not shown). Discharge conduit Don the other hand is composed of a series of pipe sections 4, which are successively larger in the direction of fiow, to provide an elongated manifold of gradually increasing size having discharge connection with air filtering and powder collecting appliances E. The first and largest section of pipe in air line C is arranged opposite the smallest pipe section in the conveyor or discharge line D, and the smallest pipe section in air line C is opposite the last and largest pipe section in discharge line D. The respective pairs of pipe sections are connected together by a series of branch pipes 5 and ejectors F which extend from one pipe section to the other at an inclination in the direction of flow, say at an angle of approximately forty-five degrees (45) in respect to the main pipes. A, slide valve G is embodied in branch pipe 5 to control the flow of air to ejector F, which is a tube of the Venturi type having a tapering nozzle 6 therein, the outlet end of which is dimensioned according to the degree of suction desired. Ejector F has a downwardly extending intake branch 7 to which a flexible hose or tube is attached, and the lower end of this tube is connected to a tapered spout or discharge funnel 9 affixed to one side wall of stamping machine A. The round entrance or intake mouth 10 of the discharge spout .is relatively large and the spout passage curves upwardly and tapers gradually to smaller dimensions, substantially as delineated in Figs. 3 and 4. A relatively large exit in the side of the vessel is desired to reduce the speed of flow of air contiguous to the-stamping hammer so that only the very lightest and finest of the comminuted materials will be withdrawn from the stamping machine and the spout. This spout isin effect an auxiliary suction chamber in which the suction is approximately the same at its large mouth as in the working chamber itself, or 'say at approximately the same reduced atmospheric pressure, so that the speed of flow of air is considerably less at the bottom than at the top of the spout, thus promoting the separation of the finished floating products from the heavier unfinished products in this enlarged exhaust chamber and permitting the heavier separations to return to the working chambers: The stamping machine itself is closed or substantially closed to the atmosphere during stamping operations, excepting that air-tight joints are not necessarily present at the filling door 11 and/or the shaft bearing 12. Hence, stamping and reduction of the metal to a powdered condition proceeds constantly under a slight suction or a reduced atmospheric pressure, thereby preventing the escape of dust or powder from the machine at all places excepting at the discharge spout.

'A relatively low degree of suction is constantly maintained for aluminum powders,

say about one and one-half inches water gauge, at the discharge end of the spout or auxiliary chamber, so that none of the material under treatment is withdrawn until it is reduced to the desired fineness. Moreover, there is no re-working of the material after it is reduced to the desired fineness inasmuch as the finished product is withdrawn by suction as rapidly as it is produced. The product is also of uniform weight and fineness when it passes through hose 7 into ejector F, from whence it is conveyed through the Venturi tube into and through the discharge line or duct D at a high velocity, which in the case of aluminum powder is preferably about 6,000 feet per minute, under about four ounces of pressure in the tapering branch pipe 5 where connected with the main air duct or pipe C. As a result the commlnuted material cannot collect in the ejector, branch tubes, or the discharge duct D, but 1s all conveyed rapidly through these "parts to the air-filtering device and collecting bags outside of building B.

The angular relationship of the ejectors to the parallel air and discharge lines C and D, respectively, is also important in keeping the pipes and ducts free from deposits, and by using a series of ejectors at spaced intervals between the pipes the volume and velocity of flow of the air and material through the discharge line D is augmented successively in the'direction of flow. The reversely graduated arrangement of the air and discharge lines promotes uniform suction results at the successive ejectors, and a free unobstructed flow of the material through the discharge line as the air and material increases in volume. The air filterin and powder collecting apparatus E may of any suitable kind or character, located preterably outside of building B. As shown, this apparatus includes a relatively large receiver or separator 14 to decrease the ressure and to effect further separation of t e materials before the air and fine powder are directed to a series of finely-woven air filtering bags or collecting receptacles 15.

The overhead pipes C and D, and the stamping machine are electrically grounded, that is, separately, especially in case hose 7 is made of rubber or other insulating material, the purpose being to eliminate the hazard of explosion from static electricity due to friction inconveyingthe materials through the conduits at -high velocity.

What I claim is:

1. An apparatus for producing and collecting bronze powders, comprising a stamping machine embodying a plurality of stamping vessels, separate air and discharge conduits arranged parallel with respect to each other above said machine and connecting pipes between said air and discharge conduits extending at an inclination thereto in the direction of flow of theair therethrough, each of said connecting pipes containing an ejector I connected in suction relation to one of said vessels.

2. An apparatus for producing and collecting bronze powders, comprising parallel air and discharge conduits having branch connections inclined in respect thereto andejectors within said branch connections, in comblnation with a series of substantially closed stamping vessels having tubular exhaust connections with said ejectors.

3. An apparatus for producing and collecting bronze powders, comprising a plurality of stamping machines, and parallel air and discharge conduits having branch pipes provided with ejectors in exhaust connection with said machines, said parallel conduits being reversely graduated in cross section at intervals the length thereof to promote uniform suction at the successive ejectors and a free flow of the material through the discharge line.

In testimony whereof I afiix my signature. PHILIP P. NUNGESSER.

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