Abstract: The present invention is drawn to fluid delivery systems containing a pump and at least one additional element or function integrated as part of the pump assembly. Additional elements may include a heater assembly component, a filter component, an additive reservoir component, an ion generator component, an ozone generator component, an adductor component, and a pressure bypass valve component, wherein said pump and at least one element are comprising in a single apparatus. The fluid delivery systems may be useful for swimming pools, spas, jetted tubs, agricultural water delivery systems, fountains, water well systems, laundry systems and the like.

Abstract: According to various aspects, exemplary embodiments are provided of thermopneumatic capillary micropumps and manufacturing methods thereof. In one exemplary embodiment, a thermopneumatic capillary micropump generally includes a lower substrate having a pump-entrance for injecting fluids and a pump-exit for exhausting the fluids. The micropump also includes one or more micro-heaters for generating heat and electrodes for applying voltage to the micro-heaters. One or more air chambers substantially cover the micro-heaters. A pump chamber unit, which is capable of being filled up with the fluids, is coupled to the air chambers, the pump-entrance, and the pump-exit. An airing channel is coupled to the air chambers for helping maintain the pressure of the air in the air chambers at about the same level. An oxide layer is deposited on an upper substrate of the micropump. The upper and lower substrates are thermopneumatically coupled to each other.

Abstract: Pumping apparatus of the invention using thermal transpiration micropumps comprises a plurality of individual thermal transpiration micropumps distributed over a substrate (5) as a plurality of rows (A, B, C, . . . , D) each made up of a plurality of micropumps (1, 6, . . . , 7, 8, 9), thereby building up a plurality of columns (a, b, . . . , c, d). Respective heater elements (4) in each of the thermal transpiration micropumps are controlled by suitably controlling a row control conductor (10A) and a column control conductor (11a). This greatly simplifies multiplexed control of a large number of individual micropumps, thus enabling pumping capacity to be adapted.

Abstract: A system and method for using an element made of porous ceramic materials such as zeolite to constrain the flow of gas molecules to the free molecular or transitional flow regime. A preferred embodiment of the gas pump may include the zeolite element, a heater, a cooler, passive thermal elements, and encapsulation. The zeolite element may be further comprised of multiple types of porous matrix sub-elements, which may be coated with other materials and may be connected in series or in parallel. The gas pump may further include sensors and a control mechanism that is responsive to the output of the sensors. The control mechanism may further provide the ability to turn on and off certain heaters in order to reverse the flow in the gas pump. In one embodiment, the pump may operate by utilizing waste heat from an external system to induce transpiration driven flow across the zeolite.

Abstract: A fluid control mechanism includes a laser irradiation control unit to control irradiation of a light beam generated by a laser generation unit, and a liquid tank, having at least one liquid passing port and a lens to collect the light beam in the liquid tank, to hold liquid. The laser irradiation control unit emits the light beam to the lens to collect the light beam by the lens, thereby causing thermal expansion of the liquid in the liquid tank, to control inflow/outflow of the liquid via the liquid passing port.

Abstract: An exposure head, includes: imaging optical systems which are arranged in a first direction; light emitting elements which are arranged in a second direction orthogonal to or substantially orthogonal to the first direction and emit lights to be imaged by the imaging optical systems; a first wiring which is connected with the light emitting element located at a first side in the second direction; and a second wiring which is connected with the light emitting element located at a second side in the second direction.

Abstract: A controlled odor generator, comprising a central processing unit, at least one micropump unit, a sensor unit and a fan. The micropump unit is housed in a casing containing odorous fluid and has a micropump array for ejecting the odorous fluid in tiny droplets. The central processing unit regulates operation of the micropump unit, allowing to control timing quantity and mixture of spread odor. The sensor unit provides the central processing unit with environmental data, like temperature, air density and humidity, as well as human body states for controlling the micropump unit. Environmental changes are followed by a change of spraying of odor, and varying taste and demand are adapted to.

Abstract: A capillary pump is provided for producing pressurized and unpressurized vapor emissions from liquid feed. In its simplest form, the capillary pump incorporates a liquid feed intake, a porous vaporization component, and a heat transfer component. Additional components, such as an insulator component, a feed pre-heat component, a liquid feed reservoir and/or delivery system, an integrated or associated heater component, a vapor collection chamber, a heat distribution component, an orifice component and/or vapor release component, may also be associated with or integrated in the improved capillary pumps. Capillary pump arrays are provided, and numerous applications for capillary pumps are disclosed.

Abstract: A method and system for installing and operating a multipurpose fire protection system is disclosed. The steps of the method include providing a water source to a structure, providing pre-assembled vertical sprinklers drops, installing vertical sprinkler drops at designated locations within the structure, and sequentially attaching flexible tubing to each drop to create a loop, whereby water is supplied to each sprinkler via two different flow paths. A system for simultaneously inducing flow and adding or removing heat from fluid in the piping includes a convection drop comprising a piping loop with a u-shaped section, the convection drop containing a fluid which has a density that varies as a function of temperature, and a thermal means for changing the temperature of fluid in the convection drop, whereby freezing of the fluid is prevented by adding heat using the thermal means and inducing the heated fluid to flow throughout the piping system.

Abstract: The present invention teaches methods of operating a pressurized cryogenic liquid gas storage tank that has a vent cooling shield around which fuel vented from a storage tank flows to cool the storage tank by reducing the influence of heat influx into the storage tank. The method of the present invention provides for reduction in the quantity of fuel loss during the venting operation and allows a greater volume of liquid fuel to be stored in the storage tank. The method includes allowing fuel in a storage tank to transition between a two-phase state of liquid and gas into a single-phase state of liquid and back into a two-phase state of liquid and gas. Additionally, the present invention allows filling a storage tank to a liquid level greater than about 95% of the capacity of the storage tank.

Abstract: A pump for a gas sampling or analyzing system includes a pump body having walls impervious to the gas and an electrical coil within the body. The pump is coupled in series with a gas sensor and a gas volume containing the gas to be sampled or analyzed. By varying the amplitude of either the AC or DC current supplied to the coil, the temperature of the coil and, hence, the temperature of the gas within the pump can be varied, causing the pump to “inhale” upon lowering the temperature of the gas within the pump and “exhale” upon raising the temperature of the gas within the pump, thereby enabling the gas from the gas volume to be drawn periodically into and expelled from the sensor for sampling.

Abstract: A microelectromechanical (MEM) device for controlled movement of a fluid. The device includes a chamber having a heating element, an inlet, and a constricted egress channel.

Abstract: A number of micromachined devices including a micromachined pump for on-chip vacuum is provided. For example, a single-chip micromachined implementation of a Knudsen pump having one or more stages and which uses the principle of thermal transpiration with no moving parts is provided. A six-mask microfabrication process to fabricate the pump using a glass substrate and silicon wafer is shown. The Knudsen pump and two integrated pressure sensors occupy an area of 1.5 mm×2 mm. Measurements show that while operating in standard laboratory conditions, this device can evacuate a cavity to 0.46 atm using 80 mW input power. High thermal isolation is obtained between a polysilicon heater of the pump and the rest of the device.

Abstract: A micro-pump includes a pumping chamber having a predetermined inner space to be filled with a fluid, at least one fluid entrance and at least one fluid exit, which are connected to the pumping chamber, a heating element provided at one side of the pumping chamber to generate bubbles in the pumping chamber by heating the fluid, and electrodes for applying current to the heating element, wherein the fluid is made to flow into or out of the pumping chamber by expansion and contraction of the bubbles, and wherein a cross-sectional area of at least one of the fluid entrance and the fluid exit varies along a direction in which the fluid flows. The micro-pump has a relatively simple structure, enhanced pumping efficiency and enhanced durability.

Abstract: A vapor jet vacuum pump includes a housing having an inlet port and a foreline conduit, a vapor jet assembly within the housing, a vapor source for supplying a vapor to the vapor jet assembly, and at least one ejector stage. The ejector stage includes an ejector nozzle mounted in the foreline conduit and a fluid inlet located external to the housing and coupled by an ejector conduit to the ejector nozzle. The fluid inlet may be an air inlet for drawing in air at atmospheric pressure. The ejector stage may be driven by a backing pump coupled to the foreline conduit.

Abstract: A micro fluidic module having at least a micro fluid channel barrier comprises at least an actuator, a firing chamber, a plurality of convergent fluid outlet channel and a plurality of convergent fluid inlet channel. The actuator (e.g. a heater) boils the working fluid and generates thermal bubble and instant high pressure to eject the working fluid outside and expel the working fluid through the fluid outlet channel. Then, the working fluid refills from the fluid inlet channel. Therefore, the working fluid flows consistently through the firing chamber. The working fluid flowing through adjacent firing chambers are arranged in different or consistent directions. Therefore, the refilling speed of the working fluid is increased, and the operating frequency of the module is improved.

Abstract: This invention relates to an improvement in a process and apparatus for delivering ultra high purity liquid carbon dioxide to a point of use at pressures above ambient without pumping. In the process a high purity carbon dioxide feed in gaseous or liquid form is charged to a vessel and at least partially solidified, i.e., converted to a solid phase. As the liquid is converted to a solid phase, additional liquid is added until the vessel is at least substantially filled with slush. Once filled, the slush or solid is isochorically heated, i.e., heated at constant volume whereby the solid phase carbon dioxide is converted to a liquid. Liquid, then, is withdrawn from the vessel at a desired pressure at a rate at which the solid phase carbon dioxide is converted to a liquid.

Abstract: According to the present invention, there is provided a pulsating micro chamber including a walled chamber. The walled chamber further includes at least one pulsating portion actuable to pulse and change an interior volume of the walled chamber. The present invention further provides for a micro-fluidic pump including a micro conduit for carrying fluid therethrough and at least one actuating mechanism for peristaltically moving fluids through the micro conduit. The actuating mechanism includes a closed pocket adjacent to the conduit, a flexible mechanism defining a portion of a wall of the micro conduit, and an expanding mechanism disposed within the pocket for expanding a volume of the pocket and thereby flexing the flexible mechanism into the micro conduit thereby changing the volume of the conduit.

Abstract: The invention discloses a micropump having heating elements in which an essentially pulsed operation of the heating elements occurs by means of a control unit. The pulsed operation of the heating elements enables an exact control of the flow rate. With the aid of the control unit it is possible to keep the flow rate constant over a long period of days or to change the flow rate rapidly and precisely.

Abstract: A capillary pump is provided for producing pressurized vapor emissions, having various layers that assist in creating optimal conditions to accomplish a high maximum fluid flow rate and pressurization. Heat and liquid/vapor flows in opposing directions in pathways within the layers. The pump includes a vaporization layer having small-sized pores and with a thickness and area to reduce viscous drag of flowing liquid and vapor. An ejection layer is also included having one or more openings and an integrated heat transfer portion for conveying heat and providing a low fluidic drag area. The pump may include an insulation layer to shield the liquid in a supply area from heat and/or a preheat layer to raise the temperature of the liquid prior to the liquid entering the vaporization layer. A coating at least partially surrounds the outer surfaces of the pump to allow vapor pressure to increase.

Abstract: A thermolysis reaction actuating pump system including a first set of walls defining a channel having a cross-sectional area less than one millimeter squared, and wherein a liquid is received in the channel. A second set of walls defining a reaction chamber and a thermolytic body carried in the reaction chamber. The first set and second set of walls are constructed and arranged to allow the flow of gas from the reaction chamber into the channel. A heater is positioned to provide heat to the thermolytic body and disassociate the thermolytic body to produce gas to pump the liquid through the channel.

Abstract: A thermolysis reaction actuating pump system including a first set of walls defining a channel having a cross-sectional area less than one millimeter squared, and wherein a liquid is received in the channel. A second set of walls defining a reaction chamber and a thermolytic body carried in the reaction chamber. The first set and second set of walls are constructed and arranged to allow the flow of gas from the reaction chamber into the channel. A heater is positioned to provide heat to the thermolytic body and disassociate the thermolytic body to produce gas to pump the liquid through the channel.

Abstract: A liquid discharge head is provided having a heating member for generating thermal energy to create a bubble in liquid, a discharge port adapted to discharge the liquid, and a liquid flow path communicated with the discharge port having a bubble generating area for enabling the liquid to create the bubble. A movable member is arranged in the bubble generating area to be displaced along with the development of the bubble. A regulating portion regulates the displacement of the movable member within a desired range, and by means of energy at the time of bubble creation, the liquid being discharged from the discharge port. The regulating portion is arranged to face the bubble generating area in the liquid flow path. A support member is directly connected to the movable member. The bubble development causes the movable member and the regulating portion to be in contact forming an essentially closed space with the exception of the discharge port.

Abstract: A pump comprises a first thermal guard having holes therethrough for passing a gas, a second thermal guard having holes therethrough for passing the gas, a porous thermal transpiration material disposed between the first thermal guard and the second thermal guard, and a heating mechanism to maintain a temperature difference between the thermal guards across the thermal transpiration material.

Abstract: The present invention relates to a micro electro mechanical system (MEMS); and, more particularly, to a micro pump used in micro fluid transportation and control and a method for fabricating the same. The micro pump according to the present invention comprises: trenches formed in a silicon substrate in order to form a pumping region including a main pumping region and an auxiliary pumping region; channels formed on both sides of the pumping region; a flow prevention region having backward-flow preventing layers to resist a fluid flow; inlet/outlet regions formed at each of the channels which are disposed on both ends of the pumping region; an outer layer covering the trenches of the silicon substrate and opening portions of the inlet/outlet regions; and a thermal conducting layer formed on the outer layer and over the main pumping region so that a pressure of the fluid in the main pumping region is increased by the thermal conducting layer.

Abstract: The present invention relates to regulating the temperature of a desired medium that is applied to the exterior surface of a mammal. These devices have been used in the past but not with the ability to control the temperature of the desired medium in a predetermined ratio to the temperature of the mammal. With such control, the present invention decreases the change of discomforting the patient when the patient's temperature is being brought to a set point temperature body temperature.

Abstract: The systems and methods for no-moving parts nanopump based technology provide conversion of the electromagnetic energy in the infrared, visible, ultraviolet, gamma- and x-ray portion of the spectrum, electron and/or ion beamed radiation into the thermal energy. The thermal energy is utilized for heating up, overheating and pumping of the medium in nano- and/or micro-metric dimensional devices. Nanopump includes a source of the radiation energy connected with one side of the waveguide for transferring of the radiation energy. The transmitter with at least one transparent for the radiation energy thermal resistant tip on the other side of the waveguide is connected with at least one thermal conductive layer having good absorption properties for the radiation energy. The transmitter converts the energy from the source of the radiation energy into the thermal energy and this thermal energy can be transmitted to the medium for heating up and overheating of this medium in a close proximity to the transmitter.

Abstract: A liquid discharging head which discharges a liquid through a discharging port utilizing an energy generated by producing air bubble including side walls which are to be brought into contact with a movable member to restrict upstream growth of a bubble, thereby stabilizing liquid discharge.

Abstract: A pump(10) for pumping various primary fluids includes a body(100) having a primary fluid channel(110) defined therein, and a primary fluid supply is coupled to the primary fluid channel to supply a primary fluid to the primary fluid channel. A mechanism(130/132) is provided for introducing a secondary fluid to an interface region of the primary fluid channel to thereby define a fluid interface between the primary fluid and the secondary dry fluid in the interface region. An energy delivery(150/160) device delivers energy to the interface region to create a thermal gradient along the fluid interface. The thermal gradient results in a surface tension gradient along the interface. The primary fluid will move to compensate for the surface tension gradient.

Abstract: A micro-pump pumps either electrically conductive or non-conductive liquids through channels of the micro-pump and/or micro-devices. A conductive or non-conductive liquid, depending on the specific application of the present invention, is disposed within a liquid chamber and/or channel of the micro-pump. An energy source is then applied to the micro-pump of the present invention in order to form one or more vapor bubbles within the chamber and/or channel. Thereafter the vapor bubble(s) is collapsed, and the process of forming and collapsing the vapor bubble may thereafter be repeated. By the formation and collapsing cycle of the vapor bubble, a pumping action of the liquid is effectuated thereby transporting the liquid within the micro-pump of the present invention and/or micro-devices.

Abstract: A micro-pump for pumping either electrically conductive or non-conductive liquids through channels of the micro-pump and/or micro-devices. A conductive or non-conductive liquid, depending on the specific application of the present invention, is disposed within a liquid chamber and/or channel of the micro-pump. An energy source is then applied to the micro-pump of the present invention in order to form one or more vapor bubbles within the channel. Thereafter the vapor bubble(s) is collapsed, and the process of forming and collapsing the vapor bubble may thereafter be repeated. By the formation and collapsing cycle of the vapor bubble, a pumping action of the liquid is effectuated thereby transporting the liquid within the micro-pump of the present invention and/or micro-devices.

Abstract: A mini-environment control device includes an individual enclosure to contain a sample and to isolate it from the external environment. An array of micropumps attached to the individual enclosure generates and maintains a controlled vacuum in the individual enclosure. Transfer means introduce the sample into the individual enclosure and extract it therefrom. The micropumps of the array of micropumps can be of a type employing the thermal transpiration effect. Temperature and pressure microsensors and a gas analyzer enable the operation of the array of micropumps to be controlled by an onboard microcomputer. The atmosphere surrounding a sample is therefore controlled.

Abstract: A raising siphon for transferring fluids from a lower level to a higher level. The raising siphon works on the principal of increasing and/or decreasing the molecular size of fluids being transferred. Larger molecules are less dense than smaller molecules of the same type. Molecular manipulation occurs by the application of electrical current, magnetic flux and application of heat. When molecular expansion is applied to the intake column of fluid conduit, or siphon, a fluid flow from the intake column to the out take column is induced. Similarly when a molecular contraction force is applied to the out take column of a fluid conduit, a fluid flow is induce in the direction of the out take column. When the out take column outlet is at a higher level than the intake fluid level, an upward siphoning action is induced. Fluid flow therefore occurs in an upward direction.

Abstract: A liquid transport device has a chamber, an inlet and an outlet for supplying liquid to and from the chamber through one-way valves, and a bubble forming system for film boiling the liquid to form a precisely controlled film bubble which expands and contracts within the liquid. The expansion and contraction motion of the bubble acts as a pressure source for expelling liquid from the chamber during bubble expansion and withdrawing liquid into the chamber during bubble contraction. Pulses of heat energy are applied to the liquid to form the film bubbles, either by pulse driving an electric heating element with power pulses or by irradiating the liquid with laser beam pulses.

Abstract: In a fluid displacement system having a pressure vessel, an expansion vessel, first and second tubes in fluid communication with the two vessels, and an energy source, fluid contained within the system is transferred from one vessel to the other by activating the energy source, which in turn generates pressure in the pressure vessel. The generated pressure in the pressure vessel, in turn, displaces the fluid in the expansion vessel, and the system advantageously has no moving parts.

Abstract: A micro-machined vacuum pump is provided which may be utilized with microsensors. The pump in accordance with the present invention is preferably fabricated within a semiconductor substrate and utilizes thermal transpiration to provide compression. The pump has a plurality of flow chambers and a plurality of flow tubes to interconnect the flow chambers. The pump additionally includes means for creating a temperature differential between a first end and a second end of each flow tube to draw the gas therethrough. Drawing the gas through the flow tube increases the pressure within an adjacent flow chamber and induces a pumping action.

Abstract: A heating system for facilitating the transfer of gas from a portable cylinder in a safe and efficient manner.

Abstract: A micromachine comprises at least one heat generating unit arranged on the surface of a substrate, a housing for retaining liquid having a liquid retaining portion along the heat generating unit, and a rotator rotatively supported in the liquid retaining portion of the housing for retaining liquid. This rotator is structured to rotate by way of the boiling of liquid in the liquid retaining portion by heat generated by the heat generating unit. The micromachine, such a micropump or a micromotor, is incorporated in a liquid jet recording head to cause recording liquid to flow compulsorily in order to remove accumulated bubbles in the liquid paths for maintaining good performance of the liquid jet recording head at all times.

Abstract: An apparatus and method for evacuating gas from a chamber to reduce the pressure therein utilizes a housing having a lower, downwardly facing wall and an upper, upwardly facing wall, a first gas flow director of truncated conical shape having a larger end facing downwardly and a smaller end facing upwardly and disposed within the housing coupled to the lower wall. A plurality of stationary vanes is disposed adjacent the smaller end of the first gas flow director, for imparting a vortex flow to gas flowing therethrough. A second gas flow director of truncated conical shape and having a larger end facing downwardly and disposed within the housing and a smaller end facing upwardly is coupled to the upper wall, the surface of the second gas flow director within the housing including a plurality of longitudinal slits, each slit including outer and inner guide flaps to guide the flow of gas through the slit.

Abstract: In a micromembrane pump with pump housing top and bottom parts and a membrane structure disposed between the housing top and bottom parts such that pump chambers, valves, flow channels and a cavity system are formed between the membrane structure and the housing parts, heating means are disposed on the membrane structure in the area of the pump housing for operating said pump and the cavity system is filled with a cement for joining the membrane and the housing parts.

Abstract: The purpose of regenerative heat exchangers is to transfer the heat from one step or process of a cycle or system to an earlier step or process in the cycle or system such that the transferred heat is usefully absorbed rather than being discarded. The gas being heated is moved in a counter flow relative to the hotter fluid while being trapped between moving partitions (vanes) such that the gas so trapped is heated with a fixed volume with an increase in pressure as well as temperature. In some embodiments, the hotter as well as the cooler fluid is moved while trapped between moving partitions (vanes) so, as the cooler fluid being heated is thermally pressurized, the hotter fluid being cooled with a fixed volume is thermally pressurized. Materials and design details are selected to enhance the heat transfer between the two streams.

Abstract: A gas transfer system is provided for establishing or maintaining a predetermined gas pressure within a plenum, such as a tire. In an exemplary embodiment, the gas transfer system includes a power source, a pressure sensor, a control unit, and a gas transfer mechanism. Preferably, a gas transfer mechanism includes a micromechanical device, comprising one or more pumping units that transfer gas from one pressure zone to another. In one embodiment, pumping is accomplished, in part, by heating the gas within a sealable chamber of a pumping unit to cause the pressure of the gas to increase. In another embodiment, the change in pressure of the gas caused by compression of a tire provides a pumping force. Valves are provided for regulating movement of the gas through the gas transfer mechanism and can include electromechanical valves responsive to signals from the control unit, or passively biased valves responsive to applied gas pressure.

Abstract: In a micropump having a working chamber (1), an intake valve (2), and a discharge valve (3), the valves (2,3) are etched out of silicon wafers (4,5). The gas in the working chamber (1) is heated by a heating element (6), so that an overpressure is produced in the working chamber. A partial vacuum is created by cooling the gas in the working chamber (1). The pump action of the micropump is achieved through the succession of overpressure and partial-vacuum cycles.

Abstract: A microdevice in the form of an electrical switch. A microdevice for providing switching at a high repetition rate, including a cell divided into two chambers by a bistable movable membrane. A charge of gas in the cell and a source for directly heating the gas to increase the gas pressure and move the membrane, the source for heating including a pulsed source for generating transient gas pressure increases, with the cell including an arrangement for cooling the gas for reducing the gas pressure after an increase.

Abstract: A system for coupling a plurality of solar powered bubble pumps in series is described. By controlling the boiling temperature of the circulating fluid contained in the system, the flow of liquid between the units of the series can be balanced and the pressure differential between the first and last units can be used to convert heat energy into kinetic energy by use of an external turbine or electrical generator.

Abstract: A multiplicity of heaters 50 on the surface 10 of a hollow torus chamber 4 are employed to exobarically stimulate the fluid contained in the chamber to make a resonant traveling wave 20 which has its high pressure peaks 22 adjacent outlet ports 16 and its negative pressure peaks 26 adjacent inlet ports 12, thus pumping the fluid. The traveling wave can be composed of two waves having a phase difference. A controller 62 directs the heaters to exobarically stimulate the fluid so as to create the traveling wave in the fluid. Heaters 50 can act as anemometers to detect the position of the waves in the chamber so that the controller may determine when to add pulses to the wave. By having a traveling wave which always has a high pressure peaks 22 adjacent to outlet ports 16 and its negative pressure peaks 26 adjacent inlet ports 16, no valves are required to make the pump function, thus eliminating any moving parts in the pump.

Abstract: A heat transport system is disclosed which comprises an evaporator, a condenser, an accumulator, switching means and connecting pipe therethrough. The switching means changes the operation mode from the first mode to the second mode alternatively. In the first mode, cooled liquid flows into the accumulator. In the second mode, the capillary pressure occurring in the evaporator leads the liquid in the accumulator to the evaporator. By switching the first mode and the second mode alternatively, the heat is transported from the evaporator to the condenser. Because of the operation of the capillary pressure, the heat transport system of the present invention can work even in gravity-free environments.

Abstract: A liquid chromatographic method and apparatus is disclosed which employs an improved pump not requiring driven pistons or sliding seals. The pump comprises at least one length of tubing forming a chamber disposed between first and second check valves, controllable heating means to periodically heat liquid in said chamber effective to pump relatively low volumes of liquid from the chamber at relatively high pressures, means for measuring the pressure developed by the pump, and control means to increase and decrease the amount of heat imparted to the liquid to maintain the pump operation at a controlled pressure setpoint.

Abstract: A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

Abstract: An apparatus for the generation of compressed air is disclosed, where the supply of air from the compressor (1) to the user (6) is interrupted in case of preset user-side pressure. This apparatus prevents a freezing in case of low ambient temperatures in the pressure lines in which condensed water has formed. A temperature sensitive switching device (14, 29) responds to the actual ambient temperature. The switching device (14) does not stop the compressor (1) in case of a preset user-side pressure and in case of a falling below of a preset ambient temperature. The compressor (1) carries then the warmed-up air through a region of the device before discharging it into the surrounding atmosphere. The device is particularly suited for compressed-air generation plants in motor vehicles which are adapted to be used in cases of low ambient temperatures.