EVAPORATOR FOR GAS CHROMATOGRAPH Russian patent published in 2002 - IPC

FIELD: chromatography. SUBSTANCE: by-pass channels are located in insert placed into body of evaporator and circular channel is formed by glass tube, insert and elastic sealing ring. Carrier gas supplied through feeding branch pipe into evaporator heated to working temperature is divided inserts channel into three flows. One flow is directed in evaporation chamber, another flow is directed over by-pass channels into ring channel carrying along vapors of volatile components of rubber membrane, rubber ring and goes through branch pipe into atmosphere. Third flow, insignificant in value, passes over by-pass channel of insert through unsealed joint of butt of glass tube to insert to ring channel thanks to pressure difference existing between branch pipes of feeding and release and channels of insert and ring channel connected to them. Value of this flow is inversely proportional to pneumatic resistance of joint of butt of glass tube to insert and its existence prevents transfer of carrier gas polluted by vapors of volatile components of seals from ring channel to evaporation chamber. Thus flow of pure carrier gas flowing over feeding branch pipe into evaporation chamber is reliably isolated from flow of carrier gas polluted with vapors of volatile components of rubber seals-membrane and ring. EFFECT: increased quality of gas chromatographic analysis thanks to notable decrease of probability of vapors of volatile components of seals of evaporator hitting chromatographic column. 2 dwg