US2901006A - Vacuum bailing boat particularly for baths of molten metal - Google Patents

Description

Aug. 25, 1959 s. ANDREWS 2,901,006

VACUUM BAILING BOAT PARTICULARLY FOR BATHS OF MOLTEN METAL Filed Jan. 25', 1958 v III I MI,

:III LI I I l h hil INVE/VT'OR STEVE ANDREWS By Maw Aflarney United States Patent 2,901,006 VACUUMBAILING BOAT PARTICULARLY roR w BATHSOF MOLTEN METAL Steve Andrews, Fairless' Hills, Pa *assignor *to United States Steel Corporation, aKEOI'POIfafiOH of New "Jersey The present invention relates generally to material handling equipment and more "particularlyito amaterial transfer vessel in the form ofra vacuum bailing boat especially suitable for use with molten metal.

In the art of coating objects with a corrosion-resistant metal such as zinc or tin by means of a hot dip process wherein the objects to be coated are dipped into a molten bath of the coating material, it is often necessary to remove or transfer the molten metal from the primary container to another container in order to facilitate repairs or replacement of the primary container. Prior to the present invention various devices such as dip buckets, scoops, ladies and pumps were used to transfer the molten metal from the primary container. None of these devices performed in a fully satisfactory manner since they were slow acting and ineflicient. The prior art devices were particularly unsatisfactory when used for removing molten metal from the lower extremities of deep containers. The rate of metal removal with these devices progressively diminished as the metal level in the primary container decreased.

It is accordingly, an object of the present invention to provide an improved material transfer vessel for removing molten metal or similar fluid material from a primary container and transferring it to another container in an expeditious manner at a consistent and fast rate regardless of the depth of the molten metal in the primary container.

It is a further object of the present invention to provide a bailing vessel which can be disposed on a bath of molten metal and then be filled readily with molten metal by reducing the pressure on the interior of the vessel.

These and other objects will become more apparent after referring to the following specification and attached drawings, in which:

Figure l is a longitudinal sectional view showing the device of the invention in position prior to filling; and

Figure 2 is a view similar to Figure 1 showing the device after filling.

Referring more particularly to the drawings reference numeral 2 designates a galvanizing kettle or primary container of conventional design containing a bath M of molten zinc. In Figure 1 the bailing boat of the invention, designated generally by reference numeral 4, is shown suspended in bailing position afloat on the bath M.

The bailing boat 4 is a substantially air-tight vessel substantially in the shape of a rectangular parallelepipedon having a downwardly and angularly extending spout 6 integral with one end thereof. The opening 8 on the bottom end of spout 6 is in a horizontal plane lower than the bottom of the boat 4 when the boat is in horizontal position. This insures submersion of the spoutend when the boat is positioned on the surface of the molten bath, as shown in Figure 1.

An opening 10 is provided in the top of the boat 4 for connection with an air evacuating device which I have shown in the form of a steam syphon 12 supplied by a steam hose from a boiler (not shown). Other air evacuating means such as van air syphon, vacuum pump and other commercially available vacuum producing equipment could betused insteado'f the steam syphon if desired.

An-inspect ionport il4 is provided in vthe top .of the boat to fHGllllfllGrPCl'lQdlC inspection and also to permit the removal of any metal build-up linthe boat or openings therein after use,

Spacedchain lugs 16 and 18 which arefixedly attached to (the .boat as qby welding -or similar means are provided for snspendingthe boat from the main "hook '20 and auxiliary hook ZZ of-an overheadcrane .(not shown) by means of chains .24 and 26, respectively.

A.vacuum gauge 28 isco-nnected-to the boat in communication with ithe interior thereof through opening 10 for indicating pressure on theinside of the boat.

T he specific gravity. or the molten bath being trans ferred and-the weight of'the bailingboat 4 will the horizontal position of opening8 of spout 6 relative to the bottom of the boat during a bailing operation. As pointed out above, the opening 8 is always submerged below the surface of the molten bath when the boat is in bailing position. For the removal of the last load of molten metal from the primary container it is preferable for the opening 8 not to be in contact with the bottom of the primary container. This may be accomplished by manipulating the overhead crane so that the boat is suspended at a suitable height relative to the bottom of the container. Another means for accomplishing this is to provide lugs (not shown) on the bottom of the boat 4 so that the spout opening 8 would be slightly above the bottom of the primary container when the lugs were resting thereon.

In operation, the bailing boat 4 is positioned on the surface of the molten bath with its bottom floating in the bath, as shown in Figure 1. When the boat is in this position the open end 8 of the spout 6 is submerged. Then the steam syphon 12 is actuated to reduce the pressure on the inside of the boat. When this pressure has been reduced sufliciently the molten metal rapidly fills the vessel. After the vessel has been filled the steam syphon is de-actuated and the vessel is hoisted out of the galvanizing kettle to transfer the molten metal to another container.

The bailing boat 4 of the invention is built shallow to expedite filling. The vessel is no dimensioned that when it is in bailing position the vertical distance, designated x, from the plane containing opening 8 to the spillover point, designated 0, of the spout is always greater than the vertical distance, designated y, from the liquid level line of the primary container 2 to the spill-over point 0. By restricting distance x, to under 10 inches and y, always being less than distance x the bailing boat 4 will operate at the lower negative pressures for handling heavy fluids such as molten zinc and molten lead in order to expedite the filling of the boat. For example, molten zinc which theoretically can be made to rise to a height of approximately 60 inches in a perfect vacuum at sea level, can 'be made to use distance y in spout 8 by creating a negative pressure inside boat 4 approximately one-seventh of a perfect Vacuum (i.e. 4 to 5 inches of mercury column).

Similarly, molten lead, which will rise to a height of approximately 36 inches in a perfect vacuum at sea level, can be made to rise distance y by creating a negative pressure inside of boat 4 equivalent to approximately one-fourth of a perfect vacuum (i.e. 7 to 8 inches of mercury column).

The desired volume to be carried by the boat is obtained by establishing the width and length dimensions of the boat 4 accordingly.

While one embodiment of my mvention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claim.

I claim: I

A bailing boat for removing molten metal fluid and the like from an open top container which comprises a fluid-tight vessel substantially in the shape of a rectangular parallelepipedon, said vessel being substantially shallow and having a length substantially greater than its height, a downwardly and angularly extending spout on one end of said vessel, said spout communicating with the interior of said vessel, said spout being rigid and forming an integral part of said vessel, the junction of said spout with the end of said vessel constituting a spill-over point for fluid traveling through said spout into said vessel, said spill-over point beingin a horizontal plane above the horizontal plane containing the bottom of said vessel when the longitudinal axis of said vessel is in a horizontal plane, the distance between the horizontal plane containing the free end of said spout and the horizontal plane containing said spill-over point being greater than the distance between the horizontal plane containing the spill-over point and the horizontal plane containing the bottom of said vessel when the longitudinal axis of said vessel is in a horizontal plane, a connection on said vessel to an air evacuating means for reducing the pressure in said vessel, said last named means being an ejector mounted on the top of said vessel, a first lift lug on the vtop of said vessel adjacent the end thereof remote from said spout, a second lift lug on the top of said vessel spaced from said first lift lug at a point adjacent the end of the vessel from which said spout projects, a first lifting means attached to said first and second lift lugs whereby said vessel is adapted to be lifted in a level position, and a second lifting means attached to said first lift lug whereby said vessel can be tilted from a level position to a position wherein the end of said vessel from which said spout projects is below the end of the vessel adjacent said first lift lug to thereby cause emptying of said vessel.

References Cited in the file of this patent UNITED STATES PATENTS 2,223,553 Davis et al. Dec. 3, 1940

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