Industry News

Equipment safety features cryogenic oxygen legal

2014/04/18

Method using cryogenic oxygen , the first to liquefy the air , according to an oxygen , nitrogen, different boiling points to separate them . Liquefied air temperature must be reduced to -140.6 ℃ or less . Air separation is generally at a temperature range of -172 ~ -194 ℃ conducted . Legal oxygen by cryogenic device has the following characteristics:
1 ) cryogenic heat exchangers cryogenic vessels , distillation , etc. and pipes placed in the cold box , and filled with low thermal conductivity of the insulating material to prevent heat from the surrounding incoming reduce cold damage, or the device can not run ;
2) The material for cryogenic equipment , require sufficient strength at low temperatures and toughness, and good welding workability . Common aluminum alloy, copper alloy, stainless steel and other materials ;
3 ) high boiling point impurities in the air , such as moisture , carbon dioxide , should be pre- cleared at room temperature . Otherwise it will clog the channel inside the device , so the device does not work ;
4 ) air acetylene and hydrocarbons into the air separation tower , accumulated to a certain extent , affect the safe operation of , or even explosion. Therefore , you must set purification equipment to clear it ;
5 ) closed cryogenic liquid storage container when heat into the outside world , there will be part of the cryogenic liquid absorbs heat and vaporization , the pressure is automatically increased. To prevent overpressure safety device must be set up reliable ;
6 ) cryogenic liquid leak into the foundation, will be the foundation cracking , tilting the device . We must ensure that equipment, piping and valves sealing, thermal expansion and contraction to consider stress and deformation that may arise ;
7 ) is liquid oxygen impregnated wood , coke and other porous organic materials , when exposed to fire or give a certain impact, intense blasting will occur . Consequently, the cooling box does not allow the porous organic material. For liquid oxygen emissions, should anticipate a dedicated oxygen discharge piping and containers , can not walk trench ;
8 ) Long-term impact of cryogenic liquid carbon steel plate will rattle . Therefore , cryogenic liquid discharge pipe and discharge chutes can not use carbon steel products ;
9 ) nitrogen, argon is asphyxiating gas , liquid discharge pipe which should lead to the outdoors. Gas discharge pipe should be a discharge height, not toward the platform stairs outfall ;
10 ) Oxygen is a strong oxidizer , which can not be discharged directly discharge pipe in unventilated factories.