摘要:
To supply supercritical fluid to an automatic supercritical fluid extractor and collect extract from the extractor, sample holding cartridges are lifted one by one in series by an elevator plug into a pressure chamber. An inlet at the top of the cartridge engages a pressure vessel inlet for the extractant so that extractant flows into the cartridge and into the space between the cartridge and inner walls of the pressure chamber. The outlets from the cartridge and pressure vessel communicate with the collector and exhaust through passageways in the plug. The plug has cleaning ports for cleaning seals and the outlet from the cartridge flows past the seals. The collector lifts vials into place and can precool the collection solvent, and later as part of the collection procedure, heat and pressurize the collector.
摘要:
An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. In one embodiment, the extractor includes a fraction collector for extractants, an automatic sample changer and an automatic cartridge transfer mechanism which provide completely automated extractions. To automatically perform extraction, valves for the fluids are automatically opened and closed in synchronism with the insertion and removal of the cartridges. These valves force a hard valve element into a softer valve seat with a valve stem that does not rotate significantly under the control of a rotary motor.
摘要:
An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. Because of the low pressure difference, the extraction cartridge need not have the strength to withstand significant pressure and can be made out of molded plastic for disposable use as well as stainless steel and machined plastic for reusability. The extraction cartridge can be removed and opened for sample access without the use of tools. The outside of the cartridge can be purged after it is installed in a heated high pressure vessel to remove contamination from its exterior.
摘要:
An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. In one embodiment, the extractor includes a fraction collector for extractants, an automatic sample changer and an automatic cartridge transfer mechanism which provide completely automated extractions. To automatically perform extraction, valves for the fluids are automatically opened and closed in synchronism with the insertion and removal of the cartridges. These valves force a hard valve element into a softer valve seat with a valve stem that does not rotate significantly under the control of a rotary motor.
摘要:
An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. Because of the low pressure difference, the extraction cartridge need not have the strength to withstand significant pressure and can be made out of molded plastic for disposable use as well as stainless steel and/or machined plastic for reusability. The extraction cartridge can be removed and opened for sample access without the use of tools. The outside of the cartridge can be purged after it is installed in a heated high pressure vessel to remove contamination from its exterior. In one embodiment, the extractor includes a fraction collector fr extractants, an automatic sample changer and an automatic cartridge transfer mechanism which provide completely automated extractions.
摘要:
An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. Because of the low pressure difference, the extraction cartridge need not have the strength to withstand significant pressure and can be made out of molded plastic for disposable use as well as stainless steel and/or machined plastic for reusability. The extraction cartridge can be removed and opened for sample access without the use of tools. The outside of the cartridge can be purged after it is installed in a heated high pressure vessel to remove contamination from its exterior. In one embodiment, the extractor includes a fraction collector for extractants, an automatic sample changer and an automatic cartridge transfer mechanism which provide completely automated extractions.
摘要:
An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. In one embodiment, the extractor includes a fraction collector for extractants, an automatic sample changer and an automatic cartridge transfer mechanism which provide completely automated extractions. To automatically perform extraction, valves for the fluids are automatically opened and closed in synchronism with the insertion and removal of the cartridges. These valves force a hard valve element into a softer valve seat with a valve stem that does not rotate significantly under the control of a rotary motor.
摘要:
An apparatus for supercritical fluid extraction incorporates a removable extraction cartridge which in operation has insignificant pressure difference between its inside and outside walls. Because of the low pressure difference, the extraction cartridge need not have the strength to withstand significant pressure and can be made out of molded plastic for disposable use as well as stainless steel and machined plastic for reusability. The extraction cartridge can be removed and opened for sample access without the use of tools. The outside of the cartridge can be purged after it is installed in a heated high pressure vessel to remove contamination from its exterior.
摘要:
To pump supercritical carbon dioxide into a supercritical extractor without overpressure in the reservoir and to record the volume being delivered, the pumping speed is controlled and the volume pumped is determined from a pressure-related signal used in a feedback circuit. The feedback controls the velocity of pumping in conjunction with programmed values to avoid destructive reverse torque. A cam in the pump controls piston stroke, has a depressurization portion with an initial slope equal to but in the opposite direction of the final slope, rounded transition slopes, increasing linear velocity to the refill portion and constant velocity in the refill portion.
摘要:
A variable-orifice fluid restrictor for use with a supercritical extractor or chromatograph includes an inlet line for fluid at a pressure above its critical pressure, an extended tubular probe having an inner and an outer surface and a proximal and a distal end. The proximal end of the probe is disposed toward the inlet line. The distal end of the probe includes an adjustable orifice means adapted for metering the fluid and having first and second orifice members and an adjusting stem having first and second ends. The adjustable orifice means is adjacent to the outer surface of the probe and the orifice means is adjustable with the adjusting stem. The end of the adjusting stem is located at the distal end of the probe and is adapted for moving the first orifice member with respect to the second orifice member to control the adjustable orifice for varying the restriction of fluid passing through the adjustable orifice.