US2355362A

US2355362A - Method and apparatus for removing sulphur and phosphorus from molten metals

Info

Publication number: US2355362A
Application number: US443774A
Authority: US
Inventors: Donald J Campbell
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-05-20
Filing date: 1942-05-20
Publication date: 1944-08-08
Anticipated expiration: 1961-08-08

Description

- 1944. D. .1. CAMPBELL METHOD AND APPARATUS FOR REMOVING SULPHUR AND PHOSPHORUS FROM MOLTEN METALS Filed May 20, 1942 4 Sheets-Sheet 1 Inventor Douala JGaryfflw/l @lm/zm k/ Dot/ 4 Quorum 8, 1944- D J. CAMPBELL 2,355,362

METHOD AND API ARATUS FOR REMOVING SULPHUR AND PHOSPHORUS FROM MOLTEN METALS Filed May 20, 1942 4 Sheets-Sheet 2 86 a7 6 Z I 8.4- 83\ 2 millwl 118 I 17 78 5 M 6 Q @1 77 \L i Q K 7c (,2 IZADV 42 {04' Summer Ol/a/d J. an 179611 6114/11 u rad/ 5 Aug. 8, 1944. D. J. CAMPBELL METHOD AND APPARATUS FOR REMOVING SULPHUR AND PHOSPHORUS FROM MOLTEN METALS I 4 Sheets-Sheet 3 Filed May 20; 1942 3IlDlltOt C'vyflbdl 6mm 1 Rake N mN d Na Q: .3 m w H a q& gwsmv W M. :Exx qm mfin m p a a9. w? D .N 43 u mm 3 .2 an N MW MNW w w, w b ,1 51/9,, u I! 114,. 1 s W x 11.. .f g a. I h fwwifiu /5 M .n 8 mw U WWW" Gttorncg 1944- D. J CAMPBELL 2,355,362

' METHOD AND APPARATUS FOR REMOVING SULPHUR AND PHOSPHORUS FROM MOLTEN METALS FiledMayZO, 1942 4Sheets-Sheet4 Snvcntor Patented Aug. 8, 1944 METHOD AND APPARATUS FOR REMOVING SULPHUR AND PHOSPHORUS FROM MOL- TEN METALS Donald J. Campbell, Spring Lake, Mich.

Application May 20, 1942, Serial No. 443,774

9 Claims.

This invention relates, primarily, to the methd and apparatus for removing sulphur and phosphorus from molten metals and, particularly the removal of sulphur and phosphorus from molten ferrous metal; and has for objects, first, the removal of sulphur from molten ferrous metal; second, the removal of phosphorus from molten ferrous metal; third, the removal of both sulphur and phosphorus from molten ferrous metal; fourth, the removal of such other impurities as can be separated from'metals by centrifugal force while the metal is in a molten state; fifth, the general refining of molten metals, and particularly, ferrous metal.

These named objects and other objects are attained by the method described in the specification, and by the employment of the apparatus disclosed by the accompanying drawings, in Which--- Figure 1 is a side elevation view of the apparatus by which the method of removing sulphur, phosphorus and the like, are removed from the molten metal; Figure 2 is a front end elevation view of the apparatus as itappears in readiness to put in operation; Figure 3 is a sectional view of the apparatus taken on a plane extending 1ongitudinally of the apparatus from vertical line V, V, of Figure 2, and in which certain parts are shown in full line; Figure 4 is a cross-sectional view of the apparatus taken on line I, I, of Figure 1, and looking in the direction the arrow indicates; Figure 5 is a plan view of two of the resistor elements by which the lining of the apparatus is heated during the time the molten metal is not being operated upon, Figure 6 is a side view of one of the resistor heating units, and showing the ends bent and with a nut screwthreaded thereon. Figure '1 is a top plan view of the skimming apron which is hooked onto the front of the apparatus at the time of removing slag. Figure 8 is a top plan view of the electrilow shaft 12, supporting the barrel l3. The said barrel l3 consists of the structure comprising the cylindrical conical shell l4, having therein insulation lining l5, inside of which a fire brick lining I 6, having therein an inner lining of specially shaped refractory blocks l1. Each (if said blocks has its back in spaced apart'relation to the interior of the liner periphery of the refractory block lining, one or more scallops'l8 in which is held by fire clay the resistor heating units i9, having electrical connection with connector 20, an 20', or the bus rings 2| and 2| embedded in the refractory back 22. The said connectors extend through the refractory back 22, and through the back plate 23' of the shell l4,'from which the connectors are insulated by insulating sleeve 24. They are engaged by electrical con-' tact members 25 and 25', of which there is one for each pair of terminals of the resistor heating units, both of which are supported by insulating block 26, secured to carriage 21.- Slideways .23are'secured to the bearing housing at 29, and slidable in relation thereto, by adjusting screw 30 turned by hand wheel 3|, to slide the carriage 21 for making and breaking contact with the

connectors

20 and 20. Cables 3| and 32 conduct electricity-to the contact members 25 and 25'. These have connection therewith made by terminal members-33 and 34, secured to the contact members by headed screws 35. At the front of the shell I4 is molten metal tapping out hole 33, closed by botting clay plug 36, in front of which is spout 31. They comprise the metal shell 38, having upwardly 7, extending flanges 39, with lug 40 extending toward the front of the shell 14. Under this is placed the botting clay plug locking bar 4 I, engaging screwthreaded bar 42, which is there holding the botting plug in the hole 33, and thereby preventing the plug being forced out of the hole 36 by the molten metal. The spout shell 38 has refractory lining 43, whereby the shell is prevented from being melted by the molten metal as it is tapped from the barrel. At the front of the barrel I3 is inwardly extending flange M, for holding the refractory lining 43 in place, and through which at the axis of thebarrel' [3, extends skim Numeral I designates the concrete foundation hole 43 having fiatted portion 41, for increas- 'ing the capacity of the barrel when the barrel is at rest, over what it would be had there been no flat and the hole were cylindrical. The flat also provides a support for the scraper employed in skimming slag from the top of the molten metal. This skim hole 46 is always closed during processing of the metal by the rotatable sealing head 48, which is provided with an air insulating chamber 49, and composition insulating member 58. The'head 48 has trunnion 5|, extending axially from its side farthest removed from its face 52, for rotatably supporting the head around the periphery of which extends annular packing 53, for preventing air entering the barrel during processing of the molten metal. Numeral 54 refers to a sealing plate secured to the inwardly extending flange 44 of the shell I4, and engaging the packing 53. The trunnion H of the head 48 is supported by, and rotatable in bearing 55, provided, with anti-friction rollers 55, rotatable in housing 51, where they are retained by flange 58 having a portion 59, screwthreaded in the hole in the trunnion 5|. The bearing housing 51 is'of semi-spherical form, and is socketed in concave cup CI of the arm 52, extending from and forming a part of vertically extending column 58 This column 53 has supporting hinge lugs 54, extending from its back, with pivot pins 55 extending downward therefrom, through bearings 55 of brackets 51, secured to I beams, for swingably supporting the column 58, arm 52, and parts'associated therewith. The annular collar 58, which is shaped at one of its sides to the contourof the semi-spherical portion of the bearing housing, retains the bearing housing in the concave cup 5 I.

Encircling the shell I4 at its front portion, is annular track 13, engaged by rollers 14, rotatably mounted in suitable bearings carried by supporting saddle bracket 15. The said bracket has portions extending in a curve part way up each side of the arrel I3. Each portion has hinged thereto as, by pins 15, inwardly curved arms 11 and 11', each carrying roller 18 rotatable on bearing pin 18. One of said arms having lugs 80 to which is pivotally connected by pin 8|, eye bolt 82 which has screw threaded shank 88 surrounded by spring 84, secured to the shank by nut 85, wherebytension of the spring may be set. The spring :84 at its end farthest removed from the nut 85, engages washer 85 resting against slotted lug 81, extending upward from the end of the arm 11'. The purpose of this spring arrange ent is to bring the rollers 18 forcibly against e annular track 13, and against which they roll. Its purpose being to prevent the track 13 leaving the rollers 14, while at the same time by the give of the helical spring 84, allowing the track to expand without binding. Adjacent the refractory back 22, is refractory lining 82', having a recess 23' into which is set porous refractory block 28", for preventing molten metal being drawn to the air pump through tube 98.

At the rear or smaller end of the barrel shell I4, and secured thereto, is spider 88, integral with the hollow shaft I2, which is provided with an insulating chamber 89, and longitudinally extending bore 98. This chamber is closed against entrance of air thereto by packing 9|, consisting of annular disc 82 secured to the end of the hollow shaft I2 and rotatable therewith. This stationary annular flange 83 has hub 94, extending into and secured to the housing 95, extending from and forming a part of the suction pipe 95, the open top ,'of which is vacuum control closing valve 91. Th s is provided with operating lever 88. Extending longitudinally of the bore 98 of the hollow shaft, and supported therein by the hub 84, is hollow tube 99 of high heat resisting metal, or of a' suitable refractory. The lower end of the pipe is connected to the air pump I88 driven by belts IIII, engaging grooved pulley I88 on the pump shaft, and the grooved pulley I88 of the hollow shaft I2. The said grooved pulley I88 is also engaged by drive belts I84, engaging the grooved pulley I85, on the shaft of the drive motor I88, provided for operating the apparatus. Also secured to the hollow shaft I2 is brake drum I81. This is engaged by brake band I88, operated when applying brake by any suitable means for turning the screw II8, rotatably supported by bracket III, secured to the frame of the appsratus. The spider 88 has diametrically opposite the connector members 88, a notch I I2 into which dog II8 of the slidable rack II4 extends, and is operated by gear pinion on the shaft II5, on the shaft of the hand wheel II8. By this the said gear can be turned, and in so doing slide the rack II4 upward, and thereby the dog I I8 into engagement with the said notch of the spider. The said notch is so located that the drum will be held in such position, that the fiatted portion of the hole 48 will be extending horizontally below the axis of the drum.

Just previous to tappins the molten metal from the barrel I8, it is necessary to draw or skim the slag and dross from the top of the molten metal. This is done by a suitable skim bar extended into the barrel through the hole 48. This slag or dross is of a thick syrupy nature, and unless prevented would fall on the spout 81 when skimming, and prevent flow of the molten metal. Therefore, skim apron H8 is provided, having upward projecting side ribs H8 and hook like projections I28, whereby the apron is applied to the front plate 54 of the barrel, by extending the projections into the elongated holes III, extending through plate 54 and flange 44, at a higher level than the spout 81.

In carrying out the method of my invention, I provide an apparatus substantially as described. Molten metal having a temperature exceeding 2800 degrees Fahrenheit, is deposited in the barrel I 8, through the hole 48. When suflicient of the molten metal is deposited to bring its top surface of the metal almost to the surface of the flatted side 41 of the hole 45, extending through the front of the barrel when the barrel is at rest, the sealing head 48 is swung away from in front of the hole. When the molten metal has been deposited in the barrel, I swing the arm 18, and thereby the sealing head against the front sealing plate 54 of the barrel, after which I start the motor I88, and thereby rotate the barrel I8 and the molten metal therein. By starting the said motor and barrel, the air pump is started also, and by its connecting pipe 88 and tube 99 extending and open to the interior of the barrel, draw a, partial vacuum within the barrel and on the molten metal therein, which when the barrel is first started the molten metal is carried upward at the rising side of the barrel by the refractory lining blocks I1, and rolls back in an endeavor to level 011' until sufficient rotational speed is reached, which for a barrel having a six foot internal diameter the speed should approximate 200 revolutions per minute. At this speed the molten metal by the centrifugal force, is distributed over the entire inner circumference of the lining, and will have a substantially uniform inner thickness. The first tumbling or sliding back of the molten metal as the barrel starts to rotate, churns and mixes the metal, thereby working the lighter impurities from the molten metal to its inner periphery, and where the solid impurities can be skimmed 01!. When the rotative speed of approximately 200 revolutions per minute is reached, substantially all sulphur and phosphorus is squeezed out of the molten metal by centrifugal force, and drawn from the barrel by suction formed by the air pump. When the sulphur and phosphorus which are in a gaseous state in the center of the revolving mass, are drawn from the barrel by the air pump and discharged into the atmosphere, the vacuum control valve 9'! is opened, but during processing the metal the valve is employed to regulate the amount of vacuum.

Having described my invention, the rights it is desired to secure are disclosed in the hereafter named claims, and I claim:

1. Apparatus for removing sulphur and phosphorus from molten metals, comprising a conical shell of wrought metal having a back at its smaller end, and an inwardly extending flange at its larger end, with a semi-circular hole at its axis having a flattened side, the shell having a lining of heat insulating material, a second lining of refractory blocks each having a recess with a portion of an electrical heating unit therein, having a connectorexte'nding exterior of the shell for engaging an electrical contact member connected to an electrical circuit, and a third lining.

hollow shaft extending axially from the back of the said shell and rotatable in bearings supported by the apparatus, a dog latch engaging the back of the shell for preventing rotation of the shell, during the skim and tap out periods of the molten metal within the lining of the said shell, a tubular member extending longitudinally of and within the said hollow shaft, and extending into a hollow head having connection with a pipe connected to an air pump for drawing a partial vacuum in the said shell.

3. Apparatus for removing sulphur and phosphorus from molten metals, comprising a conical shell of wrought metal having a back at its smaller end, and an inwardly extending flange at'its larger end, with a semi-circular hole at its axis having a flattened side, the shell having a lining of refractory blocks within the said second lin- I ing, the said inwardly extending flange front of the shell having a refractory linging with a tap out hole at the inner periphery of the shell lining, and in radially spaced apart relation to the flattened side of the hole at the axis of the inwardly extending flange front, and having a spout extending from adjacent the said tap out hole for conveying the molten metal away from the said tap out hole, a skim apron adapted to be attached to the front of the shell between the flat side of the skim hole at the axis of the inwardly extending flange and'the said tap out hole, a' hollow shaft extending axially from the back of the said shell, and rotatable in bearings supporting an end of the shell and refractory lining therein, a dog latch engaging the back of the shell for preventing rotation of the shell during the skim and tap out periods of the molten metal within the lining of the said shell, the said dog latch forming a part of a slidable rack moved by a gear rotated by a hand wheel, a tubular member extending longitudinally of and within the said hollow shaft, and supported by a hollow head having connection with a pipe connected to an air pump, for drawing a partial vacuum in the said shell, and a valve associated with the said pipe for breaking the said partial vacuum.

2. Apparatus for removing sulphur and phos-,

phorus from molten metals, comprising a conical shell of wrought metal having a back at its smaller end, and an inwardly extending flange at its larger end, with a semi-circular hole at its axis having a flattened side,'the shell having a lining of heat insulating material, a' second lining of refractory .blocks each having a recess with a portion of an electrical heating unit therein, havof heat insulating material, and a second lining of refractory blocks each having a recess with a portion of an electrical heating unit therein, having a connector extending exterior of the shell for engaging an electrical contact member connected to an electrical circuit, the said inwardly extending flange front of the shell having a refractory lining with a tap out hole at the inner periphery of the shell lining, and in radially spaced apart relation to the flattened side of the hole at the axis of the inwardly extending flange front, and having a spout extending from adjacent the said tap out hole for conveying the molten metal away from the said tap out hole, a hollow shaft extending axially'from the back of the said shell and rotatable in bearings supan air pump for drawing a partial vacuum in the said shell.

4. Apparatus for removing sulphur and phosphorus from molten metals, comprising a conical shell of wrought metal having a back at its smaller end, and an inwardly extending flange at its larger end, with a semi-circular hole at its axis havinga flattened side, the shell having a lining of heat insulating material, a-second lining of refractory blocks each having a recess with'a portion of an electrical heating unit therein, and having a connector extending exterior of the shell for engaging an electrical contact member connected to an electrical circuit, the said inwardly extending flange front of the shell having a refractory lining with a tap out hole at the inner periphery of the shell lining, and in radially spaced apart relation to the flattened side of the hole at the axis of the'inwardly extending flange front, and having a, spout extending from adjacent the said tap out hole for conveying the molten metal away from the said tap out hole, a hollow shaft extending axially from the back of the said shell and rotatable in bearings supporting an end of the shell by the apparatus, a tubular member extending longitudinally of and within the said hollow shaft, and supported at one of its ends by a hollow head having connection with a pipe connected to an air pump for drawing a partial vacuum in the said shell.

5. Apparatus forremoving sulphur and phosphorus from molten metal, having a refractory lined conical shell, including a back and a front, the said front having a tap out hole for removing molten metal from the interior of the shell lining,

and a flattened sided hole through which to skim the molten metal, a hollow shaft extending axially from the back of the shell and rotatable in bearings supporting an end of the shell, a tubular member extending longitudinally of and within the said hollow shaft, and an air pump having connection with the said tubular member for drawing a partial vacuum at the interior of the conical shell, and means for starting and accelerating rotation of the shell having molten metal therein.

6. .Apparatus for removing sulphur from molten metal, having a refractory lined conical shell including a back, and a. front having a tap out hole for removing molten metal from the interior of the shell, a flattened hole at the axis through which to skim the molten metal, a hol- 'low shaft extending axially from the back of the shell, and rotatable in bearings supporting an end of the shell bythe. apparatus, a tubular member extending longitudinally of and within the said hollow shaft, and an air pump having connection with the said tubular member for drawing a-partial vacuum at the interior of the conical shall, and means for starting and accelerating rotation of the shell having molten metal therein.

7. Apparatus for removing phosphorus from molten metal, having a refractory lined conical shell including a back, and a front having a tap out hole for removing molten metal from the interior of the shell lining, and a flattened hole through which to skim the molten metal, a

hollow shaft extending axially from the back of the shell, and rotatable in bearings supporting a portion of the conical shell by the apparatus, a tubular member extending longitudinally of and within the said hollow shaft, and an air pump having connection with the said tubular member for drawing a partial vacuum at the interior of the conical shell.

8. Apparatus for removing sulphur from molten metal, having a refractory lined conical shell including a back, and a front having a tap out hole for removing molten metal from the interior of the shell lining, and a hole through which to skim the molten metal, a hollow shaft extending axially from the back of the shell and rotatable in bearings supporting the shaft, a tubular member extending longitudinally of and within the saidhollow shaft, air pump having connection with the said tubular member for drawing a partial vacuum at the interior of the conical shell, and means for rotating of the shell having molten metal therein.

9. In the invention comprising improvements in removing sulphur and phosphorus from molten metal, an apparatus having a refractory lined rotatable barrel, having a skim hole at one of its ends and a hollow supporting shaft extending from the opposite end through a pair of bearings, with means on the shaft for rotating the shaft and barrel and means for applying suction to the interior of the barrel through the hollow shaft.

DONALD J. CALIPBELL