Patent Publication Number: US-3874737-A

Title: Slag sand collecting hopper for a slag sand water mixture drainage silo

Description:
United States Patent 11 1 Schurhoff I 1 SLAG SAND COLLECTING HOPPER FOR A SLAG SAND WATER MIXTURE DRAINAGE SILO [75] Inventor: Walter Schurhoff, Dortmund,  
 Germany [73] Assignee: Hoesch Werke Alttiengesellschaft,  
 Dortmund, Germany [22] Filed: Dec. 11, 1973 [21] Appl. No.: 423,806  
 [30] Foreign Application Priority Data Aug, l8, I973 Germany 234l847 [52] 11.8. CI.. 302/15 (5 1] Int. Cl. 865g 53/30 [58] Field of Search 302/14-16 [56] References Cited UNITED STATES PATENTS 520,210 5/l894 Lyster 302/l4 X l.576 617 3/1926 Prince 302/15 2.078.235 4/1937 302/14 2,718,435 9/1955 Hudspcth 302/15 FOREIGN PATENTS OR APPLICATIONS 806,783 9/1935 France 302/15 51 Apr. 1, 1975 201,998 9/ I908 Germany 302/ I 5 Primary ExaminerEvon C. Blunk Assistant E.\&#39;aminerW. Scott Carson Attorney, Agent, or Firm-Walter Becker [57] ABSTRACT A slag sand collecting hopper of conical shape having its tip pointing downwardly, in which the upper portion of the hopper is connectable to the lower end of a slag waterdrainage silo while its lower end has an outflow adapted to be connected to a circulating pump for pumping drainage water back into the drainage silo. Arranged in the hopper and coaxial with its outflow is a power operable tube open at both ends and having an inner diameter greater than the diameter of the hopper outflow so that the power operable tube in its lowermost position is seated on the housing wall of the hopper to thereby trap the water-sand mixture in the hopper between the hopper wall and the outside of the power operable tube. The power operable tube is adapted by power operable means to be lifted off the outflow in the hopper but even in such elevated position has its upper edge below the water surface in the hopper.  
 3 Claims, 2 Drawing Figures SLAG SAND COLLECTING HOPPER FOR A SLAG SAND WATER MIXTURE DRAINAGE SILO In assignees copending application filed on even date herewith Ser. No. 423,807-Buescher filed Dec. 1 l, 1973 and entitled Method of and Apparatus for Processing Slags (inventor Buescher), there has been described a method and apparatus for processing slags, especially blast furnace slags, according to which the device for practicing the method comprises a draining silo serving as filtering vessel and provided with an outlet opening adapted to be closed, while the lower end of said draining silo has a conical screening cone with a screening bottom. According to this device, a shaking screen or chute and a conveyor belt are arranged below the discharge opening of said silo. This device is characterized in that at the screening bottom provided with screen slots there is arranged a conical slag sand collecting hopper for a circularing pump therebelow adapted to be turned on and off. Connected to said circulating pump is a conduit which from above leads to the filtering vessel. This device has proved useful, but it has been found that it can be improved, especially with regard to the slag sand collecting hopper. More specifically, the present invention concerns a device for processing slags, especially blast furnace slags, which comprises a drainage silo which serves as filtering ves&#39; sel and has an outlet opening adapted selectively to be closed. The lower end of said silo forms a conical screening cone with a screening bottom and has furthermore associated therewith a shaking screen or chute and a conveyor belt arranged below said outlet opening. At the screening bottom which is provided with screening slots there is arranged a conical screen ing or separating device with a circulating pump that is arranged below said screening or separating device and is adapted selectively to be turned on and off. A conduit coming from above leads into the filtering vessel.  
  it is an object of the present invention so to improve the apparatus, as set forth in the introductory part of this specification, especially the sand collecting hopper for the pump, that a fast and complete separation of the slag sand water mixture will be obtained and that the subsequent water circuit will substantially be kept free from slag sand.  
  This object and other objects and advantages of the invention will appear more clearly from the following specification, in connection with the accompanying drawings. in which:  
  HO. 1 illustrates in section the slag sand collecting hopper which is associated with the circulating pump.  
  F10. 2 shows a portion of the outlet of the sand collecting hopper with a pipe adapted to be lifted and lowered.  
  The device according to the present invention is characterized primarily in that the outlet of the conical sand collecting hopper is located at the tip of the cone and is adapted selectively to be closed by a pipe which is located inside said hopper and is adapted centrally to be lifted or lowered. The length of the pipe is so dimensioned that its upper end when in lifted position is still below the water level.  
  Expediently. at the closure end within the pipe which is adapted to be lifted and lowered, there is provided a spray ring which is L-shaped over its circumference and defines a space between said ring and the inner wall of the pipe. said spray ring being coaxially arranged with the inner wall of the pipe. The short leg of the L-shaped spray ring extends outwardly transverse to the axis of the pipe and outside the latter. Advantageously, the pipe is adapted to be lifted and lowered hydraulically or by means of the pneumatic cylinder, or the like.  
  The advantage of the slag sand collecting hopper according to the invention is seen primarily in the almost complete separation of the slag sand-water mixture and also in that the water circuit following said hopper can be held substantially free from slag sand.  
  Referring now to the drawings in detail, FlG. I shows the slag sand collecting hopper l which is of a conical shape and is arranged so as to stand on its tip. The device l communicates with a connecting pipe 2 which, in its turn, is connected to the drainage silo 3 which may be of the type set forth in assignees above mentioned copending application. The device 1 furthermore comprises an overflow pipe 4 with shut-off valve 5 and has an outlet 7 which leads to a circulating pump 6 located at a lower level than the device 1.  
  The device 1 has its upper part provided with an overflow 8 which is formed by two thin-walled rings 11, l2 arranged in radially spaced relationship to each other and arranged coaxially with regard to each other. The inner ring 11 is connected to the bottom side of the cover 9, whereas the outer ring 12 is connected to the inner surface of the outer wall l0. The outer ring 12 the upper edge of which is lower than the upper edge of ring 11 determines the water level in the device I. Within the device 1 there is arranged a hydraulic or pneumatic cylinder piston system 13 which is mounted on the cover 9 and is adapted selectively to lift and lower a pipe 14 which is open at the top and at the bottom and which is coaxially arranged with regard to the outer wall of and in housing 10 and is adapted selectively to close the outlet 7.  
  As will be seen from FIG. 2, at the closure end and within the pipe 14 there is provided a spray ring 15 the wall 15a of which has an L-shaped cross section which is radially inwardly spaced from the inner wall of the pipe 14. The short leg 16 of the spray ring 15 extends transverse to the axis of the pipe 14 and is located outside the latter while pointing radially outwardly.  
  When draining the slag sand in the drainage silo 3, the water which is still intermixed with relatively fine sand passes through the connecting pipe 2 into the device 1 while the outlet 7 is closed by the pipe 14 which by means of the cylinder piston system 13 on the cover 9 is adapted to be lifted and lowered. The valve 5 is adapted to be opened when the closure 7 is closed so that the water will, by means of the overflow pipe 4, be conveyed to a non-illustrated settling tank. The circulating pump is at this time shut off. The fine slag sand which is washed out from the drainage silo 3 deposits in the sand collecting hopper or device 1.  
  After the start of the next following drainage operation, the rotary pump 6 starts operation again, the pipe 14 is lifted by the cylinder piston system 13 whereby the outlet 7 toward the circulating pump 6 is opened again. The pipe 14 is lifted only to such an extent that its upper end still remains below the water surface. A portion of the water which returns to the drainage silo 3 through pipe 14, circulating pump 6 and pipe 17 will, when passing through the lower part of pipe 14, pass at an accelerated rate through the space between pipe 14 and the spray ring 15 of L-shaped cross section located at the closure end within the pipe 14 adapted to be lifted and lowered. The deposited slag sand in the device is subjected to turbulence by the water jet which, by means of the short horizontal leg 16, is directed toward the side wall or housing of the conical device 1 and thereby is caused to flow.  
  After a certain running period of the circulating pump 6, the slag sand deposited in the device I during the previous drainage operation and caused to flow is, through pipe 17, pumped back into the drainage silo 3. Moreover. also the slag sand obtained during the current drainage operation will, during the running period of the pump 6, return in this way to the drainage silo 3. Subsequently, the pipe 14 is lowered by means of the cylinder piston system l3 until its lower edge 14a is seated on wall 10. The outlet 7 is thus closed again, and the pump 6 is stopped with a time delay. This operation is repeated with each drainage operation.  
  It will thus be evident from the above that a watersand mixture passes through pipe 14 only as long as pump 6 is running and the outlet 7 is not closed by pipe 14. It will also be evident that the upper edge of pipe 14 must even in its elevated position be located below the water surface in order that water can flow through pipe 14 and over the spray ring 15 and can cause the sand to flow which was deposited in hopper 10 during the last drainage operation.  
  It is, of course, to be understood that the present invention is, by no means, limited to the specific showing in the drawings, but also comprises any modifications within the scope of the appended claims.  
 What I claim is:  
  1. A sand collecting hopper for use in connection with a slag processing apparatus comprising a pump, which includes: a container having conical housing walls and being adapted to be charged with a slag sand water mixture and arranged with its smallest portion pointing downwardly and with an outlet opening in said smallest portion, said outlet being connectable to a pump of a slag processing apparatus, means to maintain the water level in said hopper at a predetermined minimum water surface line, a tubular member open at both ends and arranged in substantially axial alignment with the axis of said outlet opening and having an inner diameter greater than the diameter of said outlet opening, said tubular member being movable from an ele vated position in which its lower edge is spaced from the inner surface of said conical housing wall to a lowered position in which the lower edge of said tubular member substantially sealingly engages the inner surface of said conical housing wall, and means connected to said tubular member for selectively moving the same from its lowered position to its elevated position and vice versa, the length and stroke of said tubular member being such that the upper end of said tubular member stays below said predetermined minimum water surface line in said hopper at all times.  
  2. A hopper according to claim 1, which includes a spray ring arranged in radially inwardly spaced relationship to and protruding from the lower end of said tubular member while being in substantially axial alignment with and connected to said tubular member for,  
 axial movement therewith, said spray ring having radially outwardly extending flange means located outside said tubular member for radially outwardly directing water and slag sand passing between the inner wall surface of said tubular member and the outer wall surface of said spray ring.  
  3. A hopper according to claim 1, in which the means for selectively moving said tubular member from its lowered position to its elevated position includes fluid operable cylinder-piston means.