Leland Stanford Junior University

Mmr Technologies Inc.

Femrx, Inc.

William A Little

Igor Sapozhnikov

George M Savage

Matthew James Holcomb

Melvyn N Kronick

Todd Thompson

Sam Spektor

A pressure swing adsorption (PSA) dryer for separating water and carbon dioxide from a gas stream includes two compound adsorbent columns []. Each column comprises a primary adsorption material for adsorbing water and a secondary adsorbent that adsorbs carbon dioxide. The secondary adsorbent comprises a solid amine. The secondary adsorbent may be, for example, a highly porous polystyrene matrix with amine groups bonded to the porous resin structure. Preferably, a mixture of the primary and secondary adsorbent materials forms an intermediate layer [] sandwiched between a top layer [] and bottom layer [] of pure water adsorbent material in each of the columns [

Device and method for removing water and carbon dioxide from a gas mixture using pressure swing adsorption

A cryogenic gas is liquefied using a refrigeration system [] thermally coupled at an evaporator [] to a cold end of a gas supply system [] within a dewar []. The refrigerator has a minimum temperature at an evaporator [] above the boiling point of the gas at atmospheric pressure but below the boiling point of the gas at a high pressure. Thus, the gas is compressed [] to high pressure so it condenses when cooled by the evaporator []. As it expands at a flow restrictor [], a portion evaporates and cools a fraction to the temperature of the boiling point of the gas at atmospheric pressure, producing liquefied gas. Opening a purge valve [] sends warm gas upward through heat exchange section [] and out through a three-way valve [] for defrosting. To reduce clogging, the gas supply valve [] is controlled by a gas purity sensor [

Small-scale gas liquefier

A cryosurgical system comprises a compressor unit and a probe assembly. A secondary refrigerant stream from the compressor unit pre-cools a heat exchanger within the probe assembly in a standby mode of operation. After the heat exchange is pre-cooled, a primary refrigerant stream can be passed through the cooled heat exchanger and thereafter expanded within a tissue-contacting portion of the probe assembly to achieve very low temperatures, typically minus 100&deg; C. or lower. After cooling, the refrigerant stream may be passed through the probe assembly with no or partial expansion to warm the tissue-contacting surface of the probe. A probe sheath can be used to provide sterility.

Cryosurgical system and method

A method and device is disclosed for removing residual oil and other contaminants from the refrigerant stream flowing to low-temperature stages of a cryogenic refrigerator. A stream of vapor and liquid refrigerant is injected into a cyclone chamber �32! through the inlet tube �34!. While the liquid drains down a conical section �36! and out through a liquid line �38!, the vapor phase moves up into a packing of metal platelets �42! which is, in a particular embodiment, cooled by a returning stream of cold vapor passing through a tube �48! wrapped around the column. A portion of the vapor condenses on the platelets and is maintained in equilibrium with the vapor. Since high-molecular-weight contaminants are more soluble in the liquid phase, they are carried down the column with the drops of condensate and are swept out with the liquid fraction through the liquid line �38!. Consequently, the vapor sent out a vapor line �46! and into the low-temperature stages of the refrigeration system is cleansed of all oil residues and contaminants. A low-temperature refrigeration system with such a device can be operated continuously for many months with no signs of clogging. Moreover, the fractionating column is inexpensive, contains no moving parts, and does not add significant volume to the system.

Self-cleaning cryogenic refrigeration system

A method is disclosed for maximizing the thermodynamic efficiency and the heat transfer capacity of a counter-current heat exchanger through the use of an optimized multi-component working fluid. Given the operational temperatures and pressures of the heat exchanger, the disclosure teaches a method for selecting the components for the working fluid and for determining the molar fractions of the components that determine the optimal mixture for the working fluid. Because the effective specific heat of a high pressure stream of this mixture is equal to the effective specific heat of a low pressure stream throughout the entire temperature range of the heat exchanger, the thermodynamic efficiency of the heat exchange process is maximized. In addition, because the difference between the enthalpies per unit mass of the two streams are maximized throughout the temperature range of the exchanger, this mixture provides optimal capacity for heat transfer in the heat exchanger. Such an optimal working fluid can dramatically improve the performance of a heat engine or heat pump, and is especially effective in cryogenic refrigeration systems.

Method for efficient counter-current heat exchange using optimized

A method and device is disclosed for removing residual oil and other contaminants from the refrigerant stream flowing to low-temperature stages of a cryogenic refrigerator. A stream of vapor and liquid refrigerant coming from an air-cooled condenser is injected into a cyclone chamber [32] through the inlet tube [34]. While the liquid drains down a conical section [36] and out through a liquid line [38], the vapor phase moves up into a packing of metal platelets [42] which is cooled by a returning stream of cold vapor passing through a tube [48] wrapped around the column. A portion of the vapor condenses on the platelets and is maintained in equilibrium with the vapor. Since high-molecular-weight contaminants are more soluble in the liquid phase, they are carried down the column with the drops of condensate and are swept out with the liquid fraction through the liquid line [38]. Consequently, the vapor sent out vapor line [46] and into the low-temperature stages of the refrigeration system is cleansed of all oil residues and contaminants. A low-temperature refrigeration system with such a device can be operated continuously for many weeks with no signs of clogging. Moreover, the fractionating column is inexpensive, contains no moving parts, and does not add significant volume to the system.

Self-cleaning low-temperature refrigeration system

A non-linear superconducting junction device comprising a layer of high transient temperature superconducting material which is superconducting at an operating temperature, a layer of metal in contact with the layer of high temperature superconducting material and which remains non-superconducting at the operating temperature, and a metal material which is superconducting at the operating temperature and which forms distributed Sharvin point contacts with the metal layer.

Superconductor-normal-superconductor with distributed Sharvin point

A multilayer miniature low temperature rapid cooldown refrigerator in which a central cooling chamber for a device to be continuously cooled is connected to input and output refrigerant lines by micron sized channels formed in interfaces of glass or like plates, the channels including a counterflow heat exchanger and a capillary section and the channels being so arranged as to assure rapid cooldown immediately in the region of the device to be cooled.

Fast cooldown miniature refrigerators

A microminiature cryogenic device for cooling in the milliwatt range includes a miniature refrigerator in which micron-sized fluid passages are defined in one or more internal surfaces of a laminate of glass or similar low thermal conductivity members by means of lithographic, etching or particle blasting techniques.

Micro miniature refrigerators

A multilayer miniature low temperature refrigerator wherein a cooling chamber for a device to be continuously cooled is connected to an input and an output by micron sized channels or like passages in respective different interfaces of a laminate of glass or like plates.

Refrigerators

Receptors are employed to which one or more fluroescent molecules are bound. When the receptors are bound to the epitopic sites on the surface and light of predetermined wave length is directed toward the surface, the fluorescing molecules are activated and fluoresce. In carrying out an assay, receptor is combined with an unknown suspected of containing molecules having the same epitopic sites bound to the surface. The receptor will bind to these molecules reducing the number of receptor sites available for binding to the epitopic sites on the surface. When the assay medium is contacted with the surface, the amount of receptor which binds to the surface, will be a function of available binding sites and, therefore, to the number of the molecules present in the unknown. Upon irradiation of the surface, substantially only the fluoroescent molecules bound to the surface will fluoresce. By monitoring the fluorescence, one can determine the presence and number of molecules of interest present in the unknown. The apparatus consists of a transparent solid sheet, conveniently as part of or optically connected to a prism, a light source set at an angle to provide total internal reflection at the sheet, a cell which includes the reflecting surface as a wall, and a fluorescence detector. Various optics and filters may be employed to modify the light source beam and the fluorescence beam. This work was carried out under a grant of the National Science Foundation.

Growing community of inventors

Palo Alto, CA, United States of America

William A Little