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:
To provide performance particularly in handling supercritical extraction systems, a specially designed pump includes a cam-driven, single-plunger with a cam having a profile that enables the pumping system to avoid destructive reverse torque on the cam, gear train and drive motor after the cam passes top dead center. The plunger includes a seal having one side in contact with the supercritical fluid and a mechanism for supporting and aligning the piston on the other side of the seal to maintain the piston in alignment. The piston drive has Hertzian contact with the piston. The fluid volume leaving the pump is determined by measuring only pressure or other parameters related to flow and movement of the plunger. Measurement of the fluid volume leaving the pump is useful for recording or indicating the flow rate while the pump is operating.
摘要:
In a piston pump for pumping liquid carbon dioxide at a temperature below 30 degrees Fahrenheit and pressures at least as high as 7500 psi, the volume leaving the pump is determined by measuring only pressure or other parameter related to flow and movement of the plunger. The position of the piston is measured and the resulting displacement is integrated to determine volume of fluid pumped.
摘要:
To provide performance particularly in handling supercritical extraction systems, a specially designed pump includes a cam-driven, single-plunger with a cam having a profile that enables the pumping system to avoid destructive reverse torque on the cam, gear train and drive motor after the cam passes top dead center. The fluid volume leaving the pump is determined by measuring only pressure or other parameters related to flow and movement of the plunger. Measurement of the fluid volume leaving the pump is useful for recording or indicating the flow rate while the pump is operating.
摘要:
In a piston pump for pumping liquid carbon dioxide at a temperature below 30 degrees Fahrenheit and pressures at least as high as 7500 psi at an outlet flow rate in excess of 10 milliliters per minute, the inlet to the pump and the pumphead are each cooled by thermoelectric heat exchangers that are air cooled. The pump is a cam-driven, single-plunger pump with a cam profile that enables the pumping system to avoid distructive reverse torque on the cam, gear train and drive motor after the cam passes top dead center. The volume leaving the pump is determined by measuring only pressure or other parameter related to flow and movement of the plunger. The piston of the pump is supported on both sides of the seal and the support for the piston within the pumphead are machined consentrically and colinearly to the seal gland.
摘要:
A multiple chamber sample holding cartridge is used with a supercritical fluid extractor that causes membranes dividing the cartridge into chambers to rupture upon the pressurization of the sample cartridge, thereby allowing the intermixing of materials contained in the chambers. The neutral oil and loss determination of soybean and other oilseed oils by supercritical fluid extraction is efficient with this two-chambered sample cartridge.
摘要:
A multiple chamber sample holding cartridge is used with a supercritical fluid extractor that causes membranes dividing the cartridge into chambers to rupture upon the pressurization of the sample cartridge, thereby allowing the intermixing of materials contained in the chambers. The neutral oil and loss determination of soybean and other oilseed oils by supercritical fluid extraction is efficient with this two-chambered sample cartridge.