FAST-HEATER THERMOELECTRIC REFRIGERATOR FOR CHROMATOGRAPH Russian patent published in 1999 - IPC

FIELD: thermoelectric semiconductor refrigerators for chromatographic gas analysis. SUBSTANCE: refrigerator designed for cooling and thermostatic control of chromatographic column capillary tube and its fast heating has cooling thermopiles, matrices, heat sink, fan, and is provided with heater in the form of small-diameter ceramic tube with metallized bands which carries thin-walled tube electrically insulated from bands and made of heat-conducting material. Ceramic tube houses wire-wound spiral and has thin-walled current-carrying caps soldered on its ends. Caps have holes whose diameter and that of spiral are 0.1 to 0.2 mm greater than that of capillary tube of chromatograph column. Heater- carrying capillary tube is mounted on matrix being cooled; sunk semi-cylindrical slot of matrix corresponds to outer diameter of heater thin-walled tube. Heater leads are brought out of refrigerator and fixed on two posts of frame hold-down screw through easily detachable connectors. Control unit is provided with two interlocking devices preventing heater circuit opening and reclosure and with 5-10 s time relay ensuring power supply to heater as soon as its capillary tube temperature rises to 150- 180 C. EFFECT: improved quality of analyzed gas chromatogram obtained, reduced time and cost of gas analysis with chromatograph using artificial cryogenic focusing. 1 dwg