Patent Publication Number: US-3874439-A

Title: Device for cooling the crystallizer in a plant for casting metal ingots with a periodic discharge thereof

Description:
United States Patent Korshunov et al.  
 1 DEVICE FOR COOLING THE CRYSTALLIZER IN A PLANT FOR CASTING METAL INGOTS WITH A PERIODIC DISCHARGE THEREOF [76] Inventors: Evgeny Alexeevich Korshunov,  
  pereulok Otdelny, 5a, kv. 29; Jury Avramovich Samoilovich; ulitsa Engelsa, 27, kv. 26; Valery -Pavlovich Kostrov, ulitsa Bazhova,  
 57, kv. 10; Oleg Ashotovich Aragilian, ulitsa Kuibysheva, 137, kv. 3; Vladimir Alexeevich Goryainov, ulitsa Malyshcva, 82, kv. 2; Anatoly Grigorievich Tarasov, ulitsa Lunacharskogo, 76, kv. 75, all of Sverdlovsk, USSR.  
 [22] Filed: Oct. 2, 1974 [21] Appl. No.: 429,830  
 [52] U.S. Cl. 164/283 M, 164/154, 165/34,  
 [51] Int. Cl. B22d 11/14, F28d 15/00 [58] Field of Search 164/48, 49, 82, 154, 250,  
 [56] References Cited UNITED STATES PATENTS 2,224,984 12/1940 Morin 164/49 1451 Apr. 1, 1975 FOREIGN PATENTS OR APPLICATIONS 175,671 1/1953 Austria 164/82 Primary Examiner-R. Spencer Annear [5 7] ABSTRACT A device for cooling the crystallizer in a plant for casting metal ingots comprises pipelines connecting at least two coolant vessels to the pump and the crystallizer. According to the invention, one of the vessels incorporates an arrangement for lowering the coolant temperature, while the other one incorporates a heater for raising the coolant temperature to 400C. Both vessels are connected to pipelines bringing the coolant to the crystallizer and taking it away there from, whereas the pipelines and pipe connections mount valves to ensure an alternate delivery of coolants from said vessels to the crystallizer.  
 Successive change of coolant temperature in the crystallizer brings more favourable conditions for forming an ingot and its discharge and for producing an ingot with an upgraded surface quality.  
 3 Claims, 1 Drawing Figure nrinnnn IJUUUU&#39; DEVICE FOR COOLING THE CRYSTALLIZER IN A PLANT FOR CASTING METAL INGOTS WITH A PERIODIC DISCHARGE THEREOF The invention relates to devices for cooling the crystallizers in metal ingot casting plants with a periodic discharge of ingots, primarily upwards.  
  Semi-continuous, and particularly continuous, metal casting plants have become widely popular in a relatively short period of time. There are known for example such plants of vertical, radial, curvilinear and horizontal types. I  
  Recently, there has been developed and disclosed a continuous metal ingot casting method providing for positive delivery of liquid metal through the siphon device from underneath into the curved and cooled crystallizer and a periodic discharge ofingots from the crystallizer upwards into the secondary cooling device, under the condition of a periodically variable pressure of liquid metal on the ingot crust in the crystallizer zone.  
  The known crystallizer cooling devices usually incorporate pipelines connecting the coolant vessel to the pump and the crystallizer being cooled. Water is most frequently used as a coolant, delivered from a water supply system at a temperature close to that of the ambient medium which is warmed up several degrees when passing through the crystallizer. This warmed water is cooled down by means of special facilities before being directed to the crystallizer cooling device.  
  The temperature of water delivered to the crystallizer may vary within narrow limits, but such variations are not called for by the production process requirements especially in those plants where the ingot is drawn from the crystallizer continuously.  
  However, the research and estimations performed by the inventorshave shown that the continuous metal casting process accompanied by a periodic drawing of the ingot from the crystallizer being cooled. under the conditions of varying the crystallizer coolant temperature within the given limits during stop periods in the course of drawing the ingot from the crystallizer, affords substantial technological advantages to produce a higher-quality ingot.  
  The known crystallizer cooling devices, however, are unable to vary the temperature of coolant delivered to the crystallizer within a range of several hundred degrees, for example 2(l()-4()0C, whereas this particular variation of the coolant temperature is desirable in the plants with a periodic drawing of the ingot during stop periods in the course of drawing the ingot from the crystallizer.  
  The principal object of the invention is to provide a device for cooling the crystallizer in the metal ingot casting plant, which would upgrade the quality of ingot surface.  
  Another important object of the invention is to provide such temperature conditions in the crystallizer that are favourable for forming an ingot and its subsequent extraction from the crystallizer upwards.  
  One more object of the invention is to provide such a device that would allow a liquid metal heat carrier to be used as a coolant, for example, a sodium and potassium alloy possessing high chemical activity.  
  These and other objects are achieved due to the provision of a device for cooling the crystallizer in a metal ingot casting plant with a periodic discharge of ingots,  
 comprising a coolant storage connected by a pipeline to a coolant vessel connected further by inflow and outcorporating a preheater to heat the coolant to approximately400C and said latter vessel has pipe connections to connect it to inflow and outflow pipelines, whereas the pipe connections and pipelines correspondingly have valves for an alternate connection of said vessels to or their disconnection from the crystallizer to ensure an alternate inflow of the coolant at a corresponding temperature to or its outflow from the crystallizer.  
  Due to this device the crystallizer is cooled alternately by heated and cooled coolant, thus accelerating the forming of an ingot and facilitating its discharge from the crystallizer which brings a favourable effect on forming a higher-quality outer surface of the ingot.  
  It is convenient that the device be equipped with an additional pump and the latter be connected by pipe connections to each of said coolant vessels and to the pipeline connected to the coolant storage, while the walls of said vessels above the given level of coolant therein might have holes to make up a passage for communicating these vessels with each other to transfer the coolant from one vessel to another.  
  The passage in the walls of vessels makes the latter intercommunieating, while the additional pump transfers the coolant from vessel to vessel, thus allowing the coolant temperature in each vessel to be stabilized according to the given value, and in addition, fills vessels and pipelines of the device with the coolant taken from the storage before commencing operation of the plant.  
  It is advisable that the device he provided with a reservoir to be connected by pipe connections to a source of compressed gas and to one of said coolant vessels.  
  The expediency of filling &#39;the crystallizer cooling device preminently with inert gas should be understood as follows.  
  At present, the cooling agent of the-crystallizer may be effectively represented by a liquid metal heat carrier such as a sodium-potassium alloy. Sodium and potassium are chemically active metals particularly intensively interacting with hydrogen and water vapours which as a rule are found in the air. To prevent objectionable interaction of sodium and potassium with air when the above alloy is used as a coolant it is reasonable before feeding the eoolant to the vessels to fill the inner passages of the crystallizer and the pipelines of the device pro-eminently with inert gas supplied from the above-mentioned reservoir.  
  In order to make the present invention more readily understood an actual embodiment of the device for cooling the crystallizer in a metal ingot casting plant will now be described with reference to the accompanying drawing that gives a schematical representation of the device disclosed herein, according to the invention.  
  The device for cooling the crystallizer in a metal ingot casting plant with a periodic discharge of ingots from the crystallizer incorporates a vessel 1 to contain coolant 2 of low-melting temperature. The vessel 1 is connected to an inflow manifold 3 of a crystallizer 4 by means of an inflow pipeline 5 through which the coolant is delivered to the crystallizer. Installed between the sections of the pipeline 5 is a pump 6 to deliver the coolant through the pipeline 5 to the crystallizer 4.  
  Connected to an outflow manifold 7 of the crystallizer 4 is one end of an outflow pipeline 8 for the coolant outflow from the crystallizer 4. The other end of the outflow pipeline 8 is connected to the vessel 1.  
  Provided inside the vessel 1 is an arrangement 9 for cooling the coolant 2 which is actually a coiled pipe for a cooling medium, preferably water to flow through.  
  Installed adjacent to the vessel 1 is an additional vessel 10 for a high temperature coolant 11, equipped with a heater 12 for preferentially initial heating of the coolant 11 to a temperature of approximately 400C.  
  Instead of the two vessels the device may incorporate a chamber having several compartments.  
  The vessel 10 has two pipe connections 13 and 14 through which this vessel is connected to the inflow pipeline 5 and the outflow pipeline 8.  
  Installed respectively on the pipelines 5 and 8 and pipe&#39;connections 13 and 14 are valves l5, l6, l7 and 18 for an alternate connection of the vessels 1 and 10 to alternately deliver the coolant of the given temperature to the crystallizer 4.  
 A passage 19 is made in the upper portions of the walls of the vessels 1 and 10 to allow the coolant to transfer from one vessel into another.  
 I The inner spaces of vessels 1 and 10 are also interconnected by pipe connections 20 with an additional pump 21 installed there between to transfer the coolant from one vessel into another.  
  Coupled to one of the pipe connections 20 is a pipeline 22 which is connected to a coolant storage 23. The pipe connection 20 of the vessel 10 and the pipeline 22 are fitted with valves 24.  
  One end of a pipe connection 25 may be coupled atop to either of the vessels 1 and 10, whereas the other end thereof is coupled to a reservoir 26 containing preferably an inert gas.  
  The reservoir 26 in its turn is connected through a pipe connection 27 fitted with a valve 28, to a compressed-gas source 29.  
  Installed on the pipe connection 20 coupled to the vessel 1 is a valve 31 coupled through a pipe 32 to a vacuum source (not shown in the drawing), wherein the gas pressure is below the atmospheric.  
  The recommended coolant is a liquid-metal heat carrier with low melting temperature such as a sodiumpotassium alloy which at the eutectic content (22.8 per cent sodium and 77.2 per cent potassium) has a melting point at l2C, a boiling point at 784C and is readily transferred by induction pumps. Other substances, however, may also be used as a coolant.  
  The device for cooling the crystallizer in a metal ingot casting plant functions as follows.  
  Before starting the plant for metal casting, the device is prepared for operation. For this purpose the device is first prepared for filling with the coolant, then the device is filled with the coolant, thereafter the coolant itself is correspondingly preparcd so that it could be delivered alternately at different temperatures to the crystallizer 4.  
  The preparation of the device for cooling and for filling with the coolant consists in that all the pipelines and pipe connections, the vessels 1 and 10 and the passages of the crystallizer 4 are filled preferably with an inert gas supplied from the reservoir 26. The gas is delivered to the reservoir 26 from the compressed gas source 29 through the pipe connection 27 and valve 28.  
  Having filled the device with the inert gas, the coolant should start to be filled thereinto.  
  Because a sodium-potassium alloy is recommended as a cooler the latter is transferred to the cooling device from the storage 23 through the pipeline 22 and the open valve 24 by means of the induction-type pump.  
  Inside the storage 23 the sodium-potassium alloy is kept under the bed of a mineral oil 30.  
  To make it possible to start the induction pump 21, its passage should be first filled with the coolant transferred from the storage 23. This operation can be effected after evacuation the pipeline 22 through the valve 31 installed on the pipe connection 20 coupled to the vessel 1. The zone of the valve 31 is evacuated through the pipe 32 connected to an evacuation outfit (not shown in the drawing).  
  After filling the passage of the induction pump 21 with the coolant the pump is started and at the same time the valve 31 is used to close the passage of the pipeline 32 and open that of the pipe connection 20.  
  The coolant taken from the storage 23 flows via the pipeline 22, pump 21 and pipe connection 20 first to the vessel 1, then via pipelines 5 and pipe connection 13, with valves 15 and 16 kept open, to the vessel 10 and the passage of the main induction-type pump 6.  
  Further filling of the cooling device with the coolant is effected with the induction pump 6 engaged, which first brings the coolant to the passages of the crystallizer 4, then to the outflow pipeline 8.  
  Filling of the device with the coolant may be considered complete after the pipelines, pipe connections and passages of the crystallizer 4 are fully filled with the coolant, while in the vessels 1 and 10 the coolant 2 reaches approximately the level of the passage 19 connecting the vessel 1 and 10.  
  Further, the valve 24 on the pipe connection 20 is opened and the valve 24 on the pipeline 22 is closed to shut off coolant supply from the storage 23.  
  In the course of filling the device with the coolant, the inert gas is expelled from the device into the reservoir 26, wherein it is compressed and via the reduction valve (not shown in the drawing) is finally released into the atmosphere.  
  Upon filling the device with the coolant, idle transfer of the coolant is recommended to be carried out by the pumps 6 and 21 during a certain period of time required for a complete extraction of gas from the cooling device, afterwards the pumps 6 and 21 are disengaged and all pipe connections and pipelines are closed by valves with the exception of the pipe connection 20 coupled to the vessel 1, said pipe connection being held open during operation of the device in the course of metal casting. v  
  Further preparation of the device for operation consists in that in the vessel 10 the coolant 2 is heated to the required temperature of approximately 400C (designated herein at Ref. No. 11) while the arrangement 9 installed in the vessel 1 is fed with a cooling medium, preferably water.  
  This terminates the preparation of the device for operation.  
  In the course of metal casting in the plant with a periodic discharge of ingots from the crystallizer 4, in accordance with the adopted technological process, the pump 6 periodically feeds the crystallizer 4 with the low-temperature coolant 2 from the vessel 1 and the high-temperature coolant 11 from the vessel in the alternate succession. When feeding the lowtemperature coolant 2, valves 16 and 17 are open, while valves and 18 are closed. For feeding the high temperature coolant, valves 15 and 18 are open, while valves 16 and 17 are closed.  
  The low-temperature coolant 2 and the hightemperature coolant 11, after having passed through the crystallizer 4, have their temperature raised by several degrees.  
  The following measures are taken to prevent gradual overheating of the coolants 2 and 11.  
  The low-temperature coolant 2 is cooled by giving off its heat through the arrangement 9 in which the cooling medium is circulated. The high-temperature coolant 11 is cooled by its being diluted with the low-temperature coolant 2, which is forced to flow by means of the auxiliary pump 21. In this case, the valve 24 on the pipeline 20 is opened, and the induction pump 21 forces the required amount of the low-temperature coolant 2 through the pipe connection 20 into the vessel 10, whereas the surplus of the high-temperature coolant 11 from the vessel 10 overflows into the vessel 1 via the passage 19.  
  On completion of the plant operation the coolant from the pipelines, pipe connections, crystallizer passages and the vessels 1 and 10 of the device for cooling the crystallizer 4 is returned to the storage 23 with simultaneously filling the above components of the device with the inert gas taken from the reservoir 26.  
 What is claimed is:  
  l. A device for cooling the crystallizer in a plant for casting metal ingots with a periodic discharge thereof,  
 comprising: a coolant storage; a vessel for lowtemperature coolant connected by pipeline to said storage; an arrangement for reducing the coolant temperature built in into said vessel for low-temperature coolant; an inflow pipeline connecting said crystallizer being cooled to said vessel for low-temperature coolant; an outflow pipeline connecting said crystallizer being cooled to said vessel for low-temperature coolant; a vessel for high-temperature coolant coupled by means of pipe connections to said inflow and outflow pipelines; a heater mounted in said vessel for hightemperature coolant to heat it to approximately 400C valves installed on said pipelines and pipe connections for an alternate connection of each of said vessels to said crystallizer being cooled for the purpose of an alternate inflow to or outflow from the crystallizer of the coolant of the corresponding temperature and for a correspondingly alternate disconnection of said vessels from the crystallizer; a pump connected to said inflow pipeline to alternately deliver the coolant from said vessels to said crystallizer being cooled.  
  2. A device according to claim 1, wherein an auxiliary pump is provided. connected by means of pipe connections to each of said vessels and to said pipeline coupled to said coolant storage, and the walls of said vessels above the required level of coolant contained therein, have holes forming a passage to communicate these vessels with each other.  
  3. A device according to claim 1, wherein a reservoir is provided, connected by means of pipe connections to a source of compressed gas and to one of said coolantcontaining vessels.  
  UNITED STA&#39;I.ES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3, 874,439  
 DATED April 1, 1975 INVENTOR(S) Evgeny A. Korshunov It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:  
 [22] Filing Date:  
 January 2, 1974 Signed and sealed this 20th day of May 1975,  
 (SEAL) Attest:  
  C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks