US2248541A

US2248541A - Melting and casting of metals

Info

Publication number: US2248541A
Application number: US352597A
Authority: US
Inventors: Lewis Eric Crisp
Original assignee: Magnesium Elektron Ltd
Current assignee: Magnesium Elektron Ltd
Priority date: 1939-08-16
Filing date: 1940-08-14
Publication date: 1941-07-08
Anticipated expiration: 1958-07-08

Description

July 8, 1941. E. c. LEWIS MELTING AND CASTING OF METALS Fiied Aug. 14. 1940 Patented July 8, 1941 MELTING AND CASTING OF METALS Eric Crisp Lewis, Putney, London, England, as- ,l signor to Magnesium Elektron Limited, London, w England, a British company Application August 14, 1940, Serial No. 352,597 i In Great Britain August 16, 1939 4 Claims.

yunder pressure and having a delivery pipe adapted to extend below the level of the molten metal, its upper end being outside the crucible for delivery of molten metal and means to increase the gas pressure to force the metal up the delivery pipe and out of its upper end. An example of such an apparatus is described and illustrated in the specification of Patent No. 514,994.

According to the invention, the upper end of the deliverey pipe communicates with a delivery channel member leading outwardly from the Crucible and having means to enclose the channel in all directions except in the direction of the outlet end of the channel, and a suicient part of the means for enclosing the channel is readily removable to permit a straight cleaning rod or pyrometer tube to `be inserted in the upper-:end

' of the delivery pipe and down to the molten metal. The pipe may require replacement before the channel member and the channelc-member may therefore be made of more permanent construction than the pipe and the pipe may be readily detachable from the channel member so that the latter can be readily removed and a new pipe fitted in its place. For this purpose, the channel member may contain a hole comprising a continuation oi the bore of the delivery pipe, the latter being'secured by bolts to the underside of the channel member.

'I'he above and other features of the invention (which features are dened in the appended claims) will now be described by way of example with reference to the accompanying drawing, wherein: l

Figure 1 is a side elevational view of a delivel'i7 pipe with channel member made in accordance with the invention;

Figures 2 and 3 are a front elevation and a planlview respectively of the parts shown in Figure The delivery pipe d is tapered with its smaller end uppermost and is made of thin sheet steel, for example 16 gauge and provided with stiflening ribs l, t, of similar thin material. The reason for using such thin material isv that the tube will rapidly be heated by the molten metal to a temperature above the solidication point of the metal, thus minimizing risk of freezing of the is a hole 9 through which the gas in the crucible can escape when the level of the molten metal falls below the level of this hole and this avoids spurting of metal out of the upper end of the vtube which tends to occur when the molten metal in the crucible has fallen to a low level. The upper end of the delivery pipe has a plate I2 welded to it and thisplate is bolted by bolts II against the end surface of a base plate I3 of the channel member with its bore in line with an opening It in the said member. The opening It is taperedl in the same direction as the delivery pipe and is of slightly smaller diameter so that any metal which may become frozen in the openc ing It can be readily pushed downwardly and metal in the tube. Near the lower end of the tube will fallvdown the delivery pipe into the molten metal. The channel member comprises a V- channel section I5 welded to the base plate I3 and extending from a position slightly rearwardly of the opening lo to a convenient forward position for delivery of metal into a ladle or mould: The channel extends from the crucible at an angle between the horizontal and vertical and with its outer end lower than its inner end so that thev molten metal is held against the channel by gravity so that it gravitates smoothly along the channel. The rear end of this V-channel is closed by a rear wall i@ which extends upwardly for some distance above the opening I. Two upstandingwalls i8, I9, are welded at their lower ends to the inside surface of the V-section I5 and -walls- I8, I9. The V-section I5, walls i8, I9 and lid 20 form a channel which is enclosed in all directions except in the downward or delivery direction so that any spurting molten metal will be diverted down the channel and tendency to oxidation of metal atthe upper end of the delivery pipe and in the channel is minimised. The lid 29 can, however, be lifted to provide free access to the opening itl and delivery pipe so that a cleaning rod or brush or a pyrometer tube can be inserted into the opening' IB and pushed in a straight line down the delivery pipe into the molten metal.

The channel member can be maintained in use for an almost indenite period, whereas the delivery tube becomes corroded and requires to be replaced after much less use. The delivery pipe can be readily removed from the channel structure by removing the bolts il and can be easily replaced by a new delivery pipe.

Sulphur dust maybe dropped into the

openings

22, 23, between the walls I8, I9,`and adjacent parts of the channel section and sulphur vapours or sulphur dioxide produced therefrom will penemolten metal falls into the delivery tube, the.

inert atmosphere will be drawn into the delivery pipe and minimise oxidation of metal therein.

If sulphur is dusting on to the metal in the ladle in which the metal is caught as it leaves the channel, the sulphur laden air or sulphur dioxide therefrom will likewise be drawn up the channel and may render other supply of sulphur or sulphur dioxide unnecessary.

It will be observed that the Whole unit comprislng the channel member and the delivery pipe is carried by the plate i3 which can be bolted in position on the crucible in the place indicated by the numeral i0 in Figure 1 of the speciilcation of Patent No, 514,994 with the delivery pipe inclined in about the same way as shown in that figure and bolted in position in a readily removable and gas-tight manner.

The channel is shown fixed at right angles to the axis of the delivery pipe and whilst this is a convenient arrangement, the channel may be fixed at any other suitable angle.

Instead of hinging the cover in position, it may be xed detachably by a loose pin or other suitable means.

Different sizes of delivery pipes may be desira.- ble for different types of work and the exchange of one unit for another is readily effected.

I claim.:

l. Apparatus' for dealing with molten metals comprising a crucible adapted to contain moltenmetal and gas under pressure, a delivery pipe for themolten metal adapted to extend from the upper part of the crucible downwardly and below the level of the molten metal and having its lower end freely suspended in the metal and otherwise constructed so as to be readily removable from the crucible, its upper end being outside the crucible for delivery of molten metal, lmeans to increase the gas pressure in the crucible to force the metal up the delivery pipe and out of its upper end, a delivery channel member communicating with thedelivery pipe and leading outwardly from the crucible at an angle between the horizontal and vertical and with its outer end lower than its inner end so that the molten metal is held against the channel by gravity -so that it gravitates smoothly along the channel, and means to enclose the channel in all directions except in the direction of the outlet end of the channel, a sumcient part of the means for enclosing the channel being readily movable to permit a straight cleaning rod or pyrometer tube to be inserted in the upper end of the delivery pipe and down to the molten metal.

2. Apparatus for dealing with molten metals comprising a crucible adapted to contain molten metal and gas under pressure, aV delivery pipe for the molten metal adapted to extend from the upper part of the crucible downwardly and below the level of the molten metal and having its lower end freely suspended in theV metal and otherwise constructed so as to be readily removable from the crucible, its upper end being outside the crucible for delivery'of molten metal, means to increase the gas pressure in the crucible to force the metal up the delivery pipe and out of its upper end, a delivery channel member communicating with the delivery pipe and leading outwardly from the crucible at an angle between the horizontal and vertical and with its outer end lower than its inner end so that the molten metal is held against the channel by gravity so that it gravitates smoothly along the channel member to which the delivery pipe being secured to the channel in a readily detachable manner in line with a hole in the channel which hole forms a continuation of the bore in the pipe and leads to the channel, and means to enclose the channel in all directions except in the direction of the outlet end of the channel, a suiiicient part of the means for enclosing the channel being readily removable to permit a straight cleaning rod or pyrometer tube to be inserted in the upper end of the delivery pipe and down to the molten metal.

3. Apparatus for dealing with molten metals comprising a crucible adapted to contain molten metal and gas under pressure, a delivery pipe for the molten metal adapted to extend from the upper part of the crucible downwardly and below the level of the molten metal and having its lower end freely suspended in the metal and otherwise constructed so as to be readilyv removable from the crucible, the pipe being made of thin sheet iron of the order of of'an inch thickness and having thin stiifening iins so as to absorb but little heat from the molten metal`in reaching the temperature of the molten metal thereby minimising risk of freezing of the metal in the pipe, its upper end being outside the crucible fory delivery of molten metal, means to increase the gas pressure in the crucible to force the metal up the delivery pipe and out of its upper end, a delivery channel member communicating with the delivery pipe and leading outwardly fromthe crucible at an angle between the horizontal and vertical and with its outer end lower than its inner end so that the molten metal is held against the channel by gravity so that it gravi- Atates smoothly along the channel and means to enclose the channel in all directions except in the direction of the outlet end of the channel, a sulcient part of the means for enclosing the channel being readily movable to permit a straight cleaning rod or pyrometer tube to be inserted in the upper end of the delivery pipe and down to the molten metal.

4. Apparatus for dealing with molten metals comprising a crucible adapted to contain molten metal and gas under pressure, a delivery pipe for the molten metal adapted to extend from the upper part of the crucible downwardly and below the level of the molten metal and having its lower end freely suspended in the metal and otherwise constructed so as to be readily removable from the crucible, a base plate adapted to be detachably secured to the crucible, to the underside of which base plate the delivery pipe is detachably secured, its upper end being outside the crucible for delivery of molten metal, means to increase the gas pressure in the crucible to force the metal up the delivery pipe and out of its upper end, a delivery channel member communicating with the delivery pipe and leading outwardly from the crucible at an angle between the horizontal and vertical and with its outer end lower than its inner end so that the molten metal is held against the channel by gravity so that it gravitates smoothly along the channel, and means to enclose the channel inall directions except in the direction of the outlet end of the channel, a suiiicient part of the means for en closing the channel being readily movable to permit a. straight cleaning rod or pyrometer tube to be inserted in the upper end of the delivery pipe and down to the molten metal.

ERIC cRIs'P LEWIS.