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628. Consumable electrode vacuum remelting furnaces
Classified Abstracts Vacuum Apparatus 20.
Pumping
Systems
628. Consumable electrode vacuum remelting furnaces. Great Britain. The deleterious effects of occluded oxygen, hydrogen and nitrogen on the metallurgical properties of steel are well known, and more than one method of controlling these effects has been devised. Vacuum remelting in an electric arc furnace, using the steel itself as a consumable electrode, is a method which is finding increasing use for the production of high-grade steels, though it was originally developed for melting titanium and other highly reactive metals. The equipment was originally quite small, but sizes have jncreased in the last few years, and a furnace recently commissioned at Sheffield will produce ingots weighing up to 20,000 lb. The furnace is (Author) described in the article. Anon., Engineer,
213 (5530),
19 Jan. 1962, 140-141.
20 Bell furnace bright annealing installation. Anon., Engineer, 213 (5530), 19 Jan. 1962, 145. 629.
630. Vacuum or pressure furnaces for research. Anon., Engineer, 213 (5530), 19 Jan. 1962, 145.
631. Vacuum heat treatment furnace. Anon., Engineer, 213 (5540), 30 March 1962, 587. 20 632. One-ton vacuum induction furnace. Anon., Engineer, 213 (5542), 13 April 1962, 667-668. 20 633. High-vacuum temperatures.
furnace
for metallographic
analysis
at high
Czechoslovakia. The apparatus consists of a tipping crucible to which a tubular furnace, which is connected to the vacuum and measuring equipment, is moved. The apparatus is used for heating metallographic specimens of metals and alloys which tend to oxidize at high temperatures. One or several specimens are placed in a MO boat in the crucible, which is a quartz tube with an internal diameter of 30 mm, sealed at one end. A vessel with a cooling medium is connected to the tube ; when the tube is rotated around the horizontal axis, the specimen to be quenched drops into this vessel. Liquids with a vapour pressure of < 1 x low5 mm Hg, for example Si oil, are used as cooling media. The outside of the tube is water cooled. A vacuum of 1 x lO-2 mm Hg is produced in 5 min by means of a rotary pump with a capacity of 7 m3/hr, and a vacuum down to 5 x lOA mm Hg is produced by an oil diffusion pump in 20 mm. The intensity of the heat in the furnace is regulated by means of a semi-automatic compensation thermoregulator connected with a PtjPt-Rh thermocouple which is placed inside the furnace. The maximum heating temperature of the specimens is 1100”. The temperature of the specimens is measured using a chromelalumel thermocouple which is in a quartz tube. The apparatus can be used for annealing and quenching specimens by heating in a vacuum, and also for exposing the microstructure at a high temperature, or for colour selective oxidation (in Czech). F. Slancar and V. KovanicovB, Zfutn. Listy., 16 (8), 1961,582-583.
20 : 49 634. Substitute for metal boats used in vacuum evaporation. India. This note describes a modification to a conical wire basket, used as an evaporation source, by placing a piece of foil
628-631
325
and Auxiliaries (of the same material as the wire) at the bottom of the basket to prevent powdered material from running out. (Author, modified) R. L. N. Sastry, .7. Sci. Znstrum., 38 (9), Sept. 1961, 376. 20 635. Vacuum melting research in Australia. Australia. The article describes a vacuum melting furnace supplied by Efco-Edwards High Vacuum Metallurgy Ltd. to the Australian Atomic Energy Commission. The furnace was required to : (1) be capable of melting and casting 200 kg of uranium ; (2) permit other operations, such as sintering, consumable and non-consumable ore melting, to be carried out in vacua ; (3) be capable of reaching a temperature of 1800°C using a power supply of 100 kW on a IO-in. diameter by 16%. graphite crucible ; (4) obtain an ultimate pressure of lO-B mm Hg, the speed of the pumps within the range I-1OOcr being sufficient to cope with the released gases ; (5) be constructed to minimize radioactive contamination and to allow safe decontamination. The furnace used is constructed of stainless steel and is doublewalled for water cooling. The roughing and backing pump is a Kinney GKD 310 air-ballasted rotary pump with a free air displacement of 8700 l./min capable of obtaining 10m2mm Hg in the chamber ; on full air ballast it can handle 20-30 lb/hr water vapour. One Edwards Speedivac 30B4 4-stage booster pump, connected to the pumping manifold via a refrigerated baffle and 16-in. baffle and isolation valve, provides the required high pumping speed at intermediate pressures (4500 l./sec from 1O-3 to 10-l mm Hg unbaffled and 3000l./sec from 1O-2 to 10-l mm Hg baffledy. Two Edwards Speedivac F 1605 fractionating pumps are also connected in parallel to the manifold through 16-in. baffle valves. Each has a speed of XtOOl./sec between 10v3 and IO-” mm Hg unbaffled and 300 I./set baffled with an ultimate pressure of less than 5 x lo-’ mm Hg. These two pumps are backed by an Edwards Speedivac 9B1 booster pump and the Kinney pump ; an Edwards Speedivac lS150 rotary pump is used for backing when the diffusion pumps are not connected to the chamber. The high frequency supply for the induction coil is obtained from a 100 kW 2850 c/s singlephase generator direct coupled to a 160 h.p. a.c. motor. The output from the generator is fed to the copper induction coil through switchable paper dielectric capacitors of 1250 kVAv capacity. Bottom pouring into the water-cooled mould chamber which is attached to the base of the furnace is achieved by the use of a water-cooled hemispherical copper stopper which closes a hole in the base of the crucible. As soon as the charge melts a small quantity freezes on coming in contact with the stopper and effectively seals the hole. When it is desired to discharge the contents of the crucible into the mould the stopper is withdrawn to one side and the metal plug melts in 10-30 seconds. The article also describes the instrumentation and controls, the preliminary tests and commissioning procedure, the initial experiments on the melting of uranium and the future work which it is proposed to carry out. J. N. W. J. Wright and M. E. Harper, Nuclear Engng, 6 (63), Aug. 1961, 344-347. 21.
Pumps and Pump Fluids ?I L1
636. Sorption pumps. Manufacturer’s announcement, of the Mullard type VAPIO. Anon., Brit. Commun. & Electronics, 9 (3), March 1962, 227. 21 637. Two-stage rotary vacuum pumps. Manufacturer’s announcement, by N.G.N. Electrical. Anon., J. Sci. Znsfrum., 38 (ll), Nov. 1961, 455.
Pumping
Systems
628. Consumable electrode vacuum remelting furnaces. Great Britain. The deleterious effects of occluded oxygen, hydrogen and nitrogen on the metallurgical properties of steel are well known, and more than one method of controlling these effects has been devised. Vacuum remelting in an electric arc furnace, using the steel itself as a consumable electrode, is a method which is finding increasing use for the production of high-grade steels, though it was originally developed for melting titanium and other highly reactive metals. The equipment was originally quite small, but sizes have jncreased in the last few years, and a furnace recently commissioned at Sheffield will produce ingots weighing up to 20,000 lb. The furnace is (Author) described in the article. Anon., Engineer,
213 (5530),
19 Jan. 1962, 140-141.
20 Bell furnace bright annealing installation. Anon., Engineer, 213 (5530), 19 Jan. 1962, 145. 629.
630. Vacuum or pressure furnaces for research. Anon., Engineer, 213 (5530), 19 Jan. 1962, 145.
631. Vacuum heat treatment furnace. Anon., Engineer, 213 (5540), 30 March 1962, 587. 20 632. One-ton vacuum induction furnace. Anon., Engineer, 213 (5542), 13 April 1962, 667-668. 20 633. High-vacuum temperatures.
furnace
for metallographic
analysis
at high
Czechoslovakia. The apparatus consists of a tipping crucible to which a tubular furnace, which is connected to the vacuum and measuring equipment, is moved. The apparatus is used for heating metallographic specimens of metals and alloys which tend to oxidize at high temperatures. One or several specimens are placed in a MO boat in the crucible, which is a quartz tube with an internal diameter of 30 mm, sealed at one end. A vessel with a cooling medium is connected to the tube ; when the tube is rotated around the horizontal axis, the specimen to be quenched drops into this vessel. Liquids with a vapour pressure of < 1 x low5 mm Hg, for example Si oil, are used as cooling media. The outside of the tube is water cooled. A vacuum of 1 x lO-2 mm Hg is produced in 5 min by means of a rotary pump with a capacity of 7 m3/hr, and a vacuum down to 5 x lOA mm Hg is produced by an oil diffusion pump in 20 mm. The intensity of the heat in the furnace is regulated by means of a semi-automatic compensation thermoregulator connected with a PtjPt-Rh thermocouple which is placed inside the furnace. The maximum heating temperature of the specimens is 1100”. The temperature of the specimens is measured using a chromelalumel thermocouple which is in a quartz tube. The apparatus can be used for annealing and quenching specimens by heating in a vacuum, and also for exposing the microstructure at a high temperature, or for colour selective oxidation (in Czech). F. Slancar and V. KovanicovB, Zfutn. Listy., 16 (8), 1961,582-583.
20 : 49 634. Substitute for metal boats used in vacuum evaporation. India. This note describes a modification to a conical wire basket, used as an evaporation source, by placing a piece of foil
628-631
325
and Auxiliaries (of the same material as the wire) at the bottom of the basket to prevent powdered material from running out. (Author, modified) R. L. N. Sastry, .7. Sci. Znstrum., 38 (9), Sept. 1961, 376. 20 635. Vacuum melting research in Australia. Australia. The article describes a vacuum melting furnace supplied by Efco-Edwards High Vacuum Metallurgy Ltd. to the Australian Atomic Energy Commission. The furnace was required to : (1) be capable of melting and casting 200 kg of uranium ; (2) permit other operations, such as sintering, consumable and non-consumable ore melting, to be carried out in vacua ; (3) be capable of reaching a temperature of 1800°C using a power supply of 100 kW on a IO-in. diameter by 16%. graphite crucible ; (4) obtain an ultimate pressure of lO-B mm Hg, the speed of the pumps within the range I-1OOcr being sufficient to cope with the released gases ; (5) be constructed to minimize radioactive contamination and to allow safe decontamination. The furnace used is constructed of stainless steel and is doublewalled for water cooling. The roughing and backing pump is a Kinney GKD 310 air-ballasted rotary pump with a free air displacement of 8700 l./min capable of obtaining 10m2mm Hg in the chamber ; on full air ballast it can handle 20-30 lb/hr water vapour. One Edwards Speedivac 30B4 4-stage booster pump, connected to the pumping manifold via a refrigerated baffle and 16-in. baffle and isolation valve, provides the required high pumping speed at intermediate pressures (4500 l./sec from 1O-3 to 10-l mm Hg unbaffled and 3000l./sec from 1O-2 to 10-l mm Hg baffledy. Two Edwards Speedivac F 1605 fractionating pumps are also connected in parallel to the manifold through 16-in. baffle valves. Each has a speed of XtOOl./sec between 10v3 and IO-” mm Hg unbaffled and 300 I./set baffled with an ultimate pressure of less than 5 x lo-’ mm Hg. These two pumps are backed by an Edwards Speedivac 9B1 booster pump and the Kinney pump ; an Edwards Speedivac lS150 rotary pump is used for backing when the diffusion pumps are not connected to the chamber. The high frequency supply for the induction coil is obtained from a 100 kW 2850 c/s singlephase generator direct coupled to a 160 h.p. a.c. motor. The output from the generator is fed to the copper induction coil through switchable paper dielectric capacitors of 1250 kVAv capacity. Bottom pouring into the water-cooled mould chamber which is attached to the base of the furnace is achieved by the use of a water-cooled hemispherical copper stopper which closes a hole in the base of the crucible. As soon as the charge melts a small quantity freezes on coming in contact with the stopper and effectively seals the hole. When it is desired to discharge the contents of the crucible into the mould the stopper is withdrawn to one side and the metal plug melts in 10-30 seconds. The article also describes the instrumentation and controls, the preliminary tests and commissioning procedure, the initial experiments on the melting of uranium and the future work which it is proposed to carry out. J. N. W. J. Wright and M. E. Harper, Nuclear Engng, 6 (63), Aug. 1961, 344-347. 21.
Pumps and Pump Fluids ?I L1
636. Sorption pumps. Manufacturer’s announcement, of the Mullard type VAPIO. Anon., Brit. Commun. & Electronics, 9 (3), March 1962, 227. 21 637. Two-stage rotary vacuum pumps. Manufacturer’s announcement, by N.G.N. Electrical. Anon., J. Sci. Znsfrum., 38 (ll), Nov. 1961, 455.