摘要:
An apparatus and process to effectively create an active drain for high and low pressure gas-liquid separator. The invention accomplishes a deterministic drainage rate of variable volume and viscosity liquid fractions from the separator. The mechanisms and methods thereof create a flow path from the separator that dramatically favors controlled liquid flow over a wide range of flow rates and viscosities while restricting gas flow. The invention is a superior method of drainage over conventional systems that employ pressure, vacuum, isolation valves and/or passive flow restrictors to achieve drainage of the separators. The embodiments are primarily directed to the fields of preparative supercritical fluid chromatography (SFC) and supercritical fluid extraction (SFE). An advantage of one embodiment allows the economical conversion of typical HPLC systems to state of-the-art supercritical fluid chromatography (SFC) systems with minimal modification to system components.
摘要:
An invention is claimed that enables the pumping of compressible fluids at high pressures when an accurate flow is desired. Two pressure sources, for example pumps plumbed in series, separate thermodynamic work, such as pressurization, at the first pressure source from a volumetric or matter metering function in the second pressure source. One example is a flowstream delivery for a chemical instrumentation system that is manufactured from relatively unsophisticated pumps yet delivers precise flows with low pulsation (
摘要:
A process and device for chromatography, such as preparative and analytical supercritical fluid chromatography, or supercritical fluid extraction for a liquid phase SFC collection system that separates and retains eluted components from sample injections. The process efficiently separates liquid and gas phases in the flow stream upstream of a collection vessel and without additional pressure schemes or solvent extractions imposed on the flowstream. Sample fractions are collected from sample component concentration peaks based upon the chromatographic elution of the sample components. Samples are repeatedly the injected into the mobile phase flow stream and collected into large volume collection containers, thereby allowing longer unattended run times and cost-efficient sample purification and recovery.
摘要:
A method for converting a pump for use in a flow stream containing a mixture of highly compressed gas, compressible liquid or supercritical fluid wherein the pump delivers a compressible fluid against a back-pressure regulator which in turn delivers a controllable flow rate downstream of the regulator without performing variable compressibility compensation adjustments on the pump. By using a pressurized source of compressible fluid combined with isocratic conditions, the delivery pressure from the pump is controlled at a rate higher than the downstream gradient with the back-pressure regulator, and an inexpensive pump may be used in place of specialized, expensive pumps and compressibility compensation systems for use in stems operating at or near supercritical fluid levels of compressible fluids. Significant capital and operating laboratory costs are saved through a simpler and cheaper system for accurately delivering compressible fluids into mobile phase flow streams.
摘要:
A fractionated sample collection process and device having at least one pressurized chamber used to gather and store liquid samples generated from a flow stream containing a mixture of highly compressed gas, compressible liquid, or supercritical fluid and a relatively incompressible liquid. A bank of multiple collection chambers is secured together in a frame to form a cassette unit. Each collection chamber may house a replaceable liner such as a test tube vial, to hold a fractionated liquid phase sample. After filling with sample, a collection chamber is returned to a clean state and ready for refilling with a new sample by manually or automatically replacing the liner.
摘要:
A pumping system for pumping fluids at sub-ambient temperatures where the pumping fluid, after it has been used for its analytical application, is expanded such that the energy of expansion of the pumping fluid can be employed for cooling the pump head or pumping fluid prior to pumping.
摘要:
A method and device are disclosed for performing supercritical fluid chromatography in packed columns of at least about 0.5 mm inside diameter. The column provides at least 50,000, preferably at least 100,000, theoretical plates with pressure drop across the column of at least 25 bar. The outlet pressure is controlled by the back pressure regulator. The column may comprise a plurality of individual columns in series. Separation is performed at a rate of at least 25 plates/min, preferably at least 100 plates/min.
摘要:
In a system for analyzing a chemical sample by chromatographic separation of said sample into components a method and apparatus are provided for maximizing detector resolution and minimizing duration by maintaining the linear velocity of the mobile phase at a desired level by affecting the viscosity and density characteristics of the mobile phase as it passes through a restrictor by programming the restrictor temperature.
摘要:
A device includes a gas-liquid separator that receives and separates a biphasic pressurized flow stream and delivers flow to at least one exit port enriched in vapor phase composition and at least one exit port enriched in liquid phase composition. The device further includes a low restriction inlet conduit in communication with the separator exit port enriched in liquid phase composition, and a positive displacement pump having an inlet port in communication with the inlet conduit to receive flow from the gas-liquid separator and an outlet port in communication with an outlet conduit.
摘要:
A drive mechanism for back pressure regulator used in liquid chromatography, supercritical fluid chromatography, or supercritical fluid extraction allows very fine automated control over a very wide range of pressures by combining a linear actuator compressing a spring, pushing a pin. The nozzle assembly of the regulator comprises a flow through chamber containing a diaphragm and a seat, in which the pin pushes the diaphragm against the seat, together with an upstream pressure sensor and electronic feedback control to the motor of the actuator. The BPR of the embodiments exhibits high pressure stability and extremely low pressure noise, even at moderate to high pressures. The exemplary BPR can be use at either constant pressure or to generate pressure programs where the pressure is varied versus time. Further, the nozzle assembly has a field-replaceable head, requiring no mechanical adjustment on replacement.