Patent Publication Number: US-2016243610-A1

Title: System and method for monitorinig mold flux consumption

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(e) of the earlier filing date of U.S. Provisional Patent Application No. 61/540,616 filed on Sep. 29, 2011, which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This application discloses an invention which is related, generally and in various embodiments, to the metal casting field wherein mold flux consumption is monitored. 
     BACKGROUND OF THE INVENTION 
     It is customary to apply a mold flux, which may be a powder or granular material, onto the top of a shapes mold during the continuous casting of a molten metal, typically steel, as shown in U.S. Pat. No. 6,474,398, the disclosure of which is incorporated by reference. The mold flux turns into slag when sufficiently heated by the molten steel. Typically, the mold flux being fed is in the form of a granulated powder from a bulk source such as a bag. The mold flux is fed by way of a vacuum from the bulk source to an intermediate feeder hopper. In prior arrangements such as that shown in U.S. Pat. No. 6,474,398, a constant level is maintained within the intermediate hopper with a proximity sensor which measures the level of mold flux within the hopper. The operator adjusts the set point level on a feed controller to deliver a steady feed of Mold flux from a feed box. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the invention are described herein in by way of example in conjunction with the following figures, wherein like reference characters designate the same or similar elements. 
         FIG. 1  illustrates a front view of various embodiments of a system for measuring mold flux consumption in a continuous casting operation. 
         FIG. 2  illustrates a back perspective view of the system of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     It is to be understood that at least some of the figures and descriptions of the invention have been simplified to illustrate elements that are relevant for a clear understanding of the invention, while eliminating, for purposes of clarity, other elements that those of ordinary skill in the art will appreciate may also comprise a portion of the invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the invention, a description of such elements is not provided herein. 
       FIG. 1  illustrates various embodiments of a system  10  for measuring mold flux consumption in a continuous casting operation; common parts will be represented by the same reference numeral. As shown, the continuous casting operation is for the continuous casting of any shape, from molten metal  15 , which in the illustrated embodiment is molten steel. Mold flux  11  in granular or powder form is fed onto the top of the shapes mold  13 . The shapes mold can be, by way of example, a slab mold. The mold flux  11  becomes a slag when sufficiently heated by the molten steel. 
     The system of various embodiments is indicated generally by reference number  10 . The system generally includes four major components: a transfer apparatus  12 ; an intermediate hopper  14 , a feed control apparatus  16 , and a delivery apparatus  18 . The transfer apparatus  12  transfers powder mold flux from a bulk source  20  to the intermediate hopper  14 . The bulk source of powder mold flux  20  may be, for example, a large bag or barrel. After the delivery apparatus  18  feeds powder mold flux  11  from the intermediate hopper to the top of the mold. 
     The transfer apparatus includes a vacuum  22  having an inlet port  24  to which one end  26  of a flexible suction tube  28  is connected. The other end  30  of flexible suction tube  28  extends into the bulk source  20 . Vacuum  22  has an outlet at the bottom for transferring mold flux to the intermediate hopper  14 . On the bottom of the vacuum hopper  22 , there is a valve such as a flapper  43  with a counter weight attached. While the vacuum  22  is energized this creates a seal between the flapper  43  and the bottom of the vacuum bin  22 . When the vacuum  22  stops, the weight of the material that was picked up allows the flapper  43  to open and the material drops into the intermediate hopper  14 . The intermediate hopper  14  has a fitting on the bottom that extends into the top of the feed hopper  31 . The delivery apparatus  18  includes a feed hopper  31  and feeds mold flux from a pair (could be up to six outlets) of outlet ports  32 ,  34  of the feed hopper  31  to the top of a mold. There is no contact between the intermediate hopper  14  and feed hopper  31  as this would give a false weight. 
     The delivery apparatus  18  includes a pair (could be up to six delivery tubes) of delivery tubes  36 ,  40  each having one end connectable to an outlet port  32 ,  34 , and the other end having anywhere from one to six feed heads  46  (two shown in the illustrated embodiment) disposed above a mold or series of molds. The mold flux is pneumatically fed from the feed hopper  31  with 1 inch venturi pumps  41  which are operatively connected to the outlet ports  32 ,  34 . The number of ports or 1 inch venturi pumps could vary depending on the type of continuous casting machine or shapes cast. For example: If the continuous caster is a small 6-strand billet machine, there would be a total of six molds, each mold being the size of the cast product. This would require six 1 inch venturi pumps and feed lines. 
     The control apparatus  16  includes at least one load cell  42  supporting the intermediate hopper  14  for weighing the intermediate hopper  14  and its contents of mold flux over a period of time for measuring the real time consumption of mold flux. The at least one load cell  42  preferably includes a plurality of load cells  42 , each supporting a side of the intermediate hopper  14 . There are three load cells  42  in this embodiment. Only two load cells  42 , however, can be seen in  FIG. 1 . The control apparatus further includes a programmable logic controller (PLC)  44  ( FIG. 2 ) receiving input from the load cells for controlling the operation of the vacuum  22 . The PLC  44  causes the vacuum  22  to turn on, thus causing mold flux to feed into the intermediate hopper  14 , based on a predetermined weight of the feed bin as compared to the consumption or loss of weight of mold flux calculated using the output of the at least one load cell  42 . The use of PLC  44  allows the ability to record daily mold flux consumption files. Alternative to a PLC  44 , any suitable processor having the appropriate software such as FACTORY TALK software may be used. Also, alternative to measuring mold flux consumption by weight, it may be desirable to measure mold flux consumption volumetrically. The rate of which the mold flux is delivered onto the mold can be adjusted by the operator using an operator control screen  48  on the PLC  44  that can be used for adjusting the feed rate. The operator control screen  48  is a touch screen display that gives the operator a scale of 0-100. This scale represents the mA voltage sent from the PLC  44  to the current to pressure transducers that are located in the feed hopper. Alternatively, the rate of which the mold flux is delivered onto the mold can be adjusted by the operator by a handheld wireless controller  50  in communication with a receiver  52  on PLC  44 . The wireless controller  50  can be used to control the feed rate instead of the operator control screen  48  on the PLC display. 
     Nothing in the above description is meant to limit the invention to any specific materials, geometry, or orientation of elements. Many part/orientation substitutions are contemplated within the scope of the invention and will be apparent to those skilled in the art. The embodiments described herein were presented by way of example only and should not be used to limit the scope of the invention. 
     Although the invention has been described in terms of particular embodiments in this application, one of ordinary skill in the art, in light of the teachings herein, can generate additional embodiments and modifications without departing from the spirit of, or exceeding the scope of, the claimed invention. Accordingly, it is understood that the drawings and the descriptions herein are proffered only to facilitate comprehension of the invention and should not be construed to limit the scope thereof.