| 摘要 |
PURPOSE:To make use of a high pressure gas compressor unnecessary and to reduce power cost and maintenance cost by a method wherein liq. nitrogen is compressed into a high pressure tank by means of a high pressure pump and after high pressure nitrogen gas is generated by heating and vaporizing the liq. nitrogen, it is brought to a vacuum at a specified range by means of a pressure reducing valve and put into a molten synthetic resin. CONSTITUTION:Liq. nitrogen 2 is taken out from the bottom part of a vacuum heat-insulated liq. nitrogen bomb 1 and is compressed into a high pressure tank 5 through a high pressure pump 3 and a check valve 4. In addition, quantity of heat to be necessary for vaporization heat of liq. nitrogen and heating to ordinary temp. is fed by means of a heater 6 of the bottom part of the high pressure tank 5 and the high pressure nitrogen gas 7 at ordinary temp. is temporarily stored in the high pressure tank 5. Then, after the pressure is reduced to 50-500atm by means of a pressure reducing valve 8, a compression valve 9 is opened and nitrogen gas is compressed into a molten synthetic resin in a mold 12 from a nozzle 11 of an injection molding machine 10. High pressure nitrogen gas is obtd. by using this method by utilizing the vapor pressure of liq. nitrogen without using a high pressure gas compressor. |
