Abstract: A suction duct is disposed within a shell and tube heat exchanger. The suction duct is located relatively high and above the tube bundle so as to not entrain liquid or droplets that may be splashing and spraying upward. The suction duct is configured with an area schedule in fluid communication with a flow path inside the suction duct. The flow path is in fluid communication with an outlet of the shell. This is advantageous relative to traditional top of the shell outlets which generally have higher vertical footprints. The area schedule of the suction duct can facilitate and/or maintain relatively smooth vapor flow within the shell. The area schedule can achieve vapor flows that have some uniformity along the length of the shell, which can manage and/or avoid localized vapor flow and/or local currents, such as where high velocity may be present and where entrainment can result.

Abstract: A suction duct is disposed within a shell and tube heat exchanger. The suction duct is located relatively high and above the tube bundle so as to not entrain liquid or droplets that may be splashing and spraying upward. The suction duct is configured with an area schedule in fluid communication with a flow path inside the suction duct. The flow path is in fluid communication with an outlet of the shell. This is advantageous relative to traditional top of the shell outlets which generally have higher vertical footprints. The area schedule of the suction duct can facilitate and/or maintain relatively smooth vapor flow within the shell. The area schedule can achieve vapor flows that have some uniformity along the length of the shell, which can manage and/or avoid localized vapor flow and/or local currents, such as where high velocity may be present and where entrainment can result.

Abstract: A suction duct is disposed within a shell and tube heat exchanger. The suction duct is located relatively high and above the tube bundle so as to not entrain liquid or droplets that may be splashing and spraying upward. The suction duct is configured with an area schedule in fluid communication with a flow path inside the suction duct. The flow path is in fluid communication with an outlet of the shell. This is advantageous relative to traditional top of the shell outlets which generally have higher vertical footprints. The area schedule of the suction duct can facilitate and/or maintain relatively smooth vapor flow within the shell. The area schedule can achieve vapor flows that have some uniformity along the length of the shell, which can manage and/or avoid localized vapor flow and/or local currents, such as where high velocity may be present and where entrainment can result.

Abstract: A heat exchange tube combines an external surface feature, for example having crushed fins and cavities, which can have very high boiling enhancement characteristics, with an internal surface feature, for example having high performing intersecting helices, e.g. “cross hatched” with an intersecting helix angle. The new tube can provide a high performing tube in a shell and tube evaporator that can be relatively smaller, more efficient, and that can use relatively lower refrigerant charge.

Abstract: A suction duct is disposed within a shell and tube heat exchanger. The suction duct is located relatively high and above the tube bundle so as to not entrain liquid or droplets that may be splashing and spraying upward. The suction duct is configured with an area schedule in fluid communication with a flow path inside the suction duct. The flow path is in fluid communication with an outlet of the shell. This is advantageous relative to traditional top of the shell outlets which generally have higher vertical footprints. The area schedule of the suction duct can facilitate and/or maintain relatively smooth vapor flow within the shell. The area schedule can achieve vapor flows that have some uniformity along the length of the shell, which can manage and/or avoid localized vapor flow and/or local currents, such as where high velocity may be present and where entrainment can result.

Abstract: A heat exchange tube combines an external surface feature, for example having crushed fins and cavities, which can have very high boiling enhancement characteristics, with an internal surface feature, for example having high performing intersecting helices, e.g. “cross hatched” with an intersecting helix angle. The new tube can provide a high performing tube in a shell and tube evaporator that can be relatively smaller, more efficient, and that can use relatively lower refrigerant charge.

Abstract: A shell-and-tube evaporator of a refrigerant system includes a refrigerant inlet distributor that traps a pocket of gaseous refrigerant to displace liquid refrigerant underneath the evaporator's tube bundle, thereby reducing the total charge of refrigerant in the evaporator. In some embodiments, the distributor comprises four sections interconnected by a central refrigerant feed line, which properly apportions the refrigerant to the four sections.

Abstract: A shell-and-tube evaporator of a refrigerant system includes a refrigerant inlet distributor that traps a pocket of gaseous refrigerant to displace liquid refrigerant underneath the evaporator's tube bundle, thereby reducing the total charge of refrigerant in the evaporator. In some embodiments, the distributor comprises four sections interconnected by a central refrigerant feed line, which properly apportions the refrigerant to the four sections.

Abstract: An evaporator for a refrigeration chiller includes a tube bundle in which at least a portion of the tubes of the tube bundle are immersed in a pool which include both liquid refrigerant and is lubricant. Liquid refrigerant and lubricant are deposited into the pool at a first pool location. Because of the vaporization of refrigerant that occurs within the pool, a pattern of flow is established and managed that causes the lubricant in the pool to migrate from the location of its deposit into the pool to a second pool location. An outlet is provided at the second pool location from which lubricant is drawn out of the evaporator.

Abstract: An evaporator for a refrigeration chiller includes a tube bundle in which at least a portion of the tubes of the tube bundle are immersed in a pool which include both liquid refrigerant and is lubricant. Liquid refrigerant and lubricant are deposited into the pool at a first pool location. Because of the vaporization of refrigerant that occurs within the pool, a pattern of flow is established and managed that causes the lubricant in the pool to migrate from the location of its deposit into the pool to a second pool location. An outlet is provided at the second pool location from which lubricant is drawn out of the evaporator.

Abstract: A fluid level sensor. The sensor comprises a housing; a chamber enclosed by the housing; a liquid port in a lower area of the housing operable to connect the chamber to a lower, liquid containing area of a heat exchanger; and a gas port located in an upper area of the housing and operable to connect the chamber to an upper, vapor containing area of a heat exchanger. The sensor includes first and second apertures in the housing; and cooling conduit passing through the chamber and through the first and second apertures and operable to cool the chamber. There is at least one sensor located in the chamber and adapted to sense a temperature of fluid in the chamber.

Abstract: Noise reduction in a screw compressor based refrigeration system is achieved by the use of multiple compressor discharge and/or suction lines. The lines are configured and/or fabricated from materials which reduce system noise which would otherwise be induced by vibration as well as the system noise associated with gas pulse energy in the discharge gas stream flowing from the compressor.

Abstract: An air valve actuated by an electric motor has a cylindrical inlet section. The inlet section defines a seating surface upstream of which is a support grid. A backplate, upon which the actuating motor is mounted, is fixedly supported by a plurality of rods that extend downstream of the inlet section. A damper assembly includes a generally planar damper mounted for movement axially of the inlet section. The damper assembly includes a splined rod which extends upstream and into a cooperating spline in the support grid. A threaded spindle extends downstream of the damper plate through a cooperatively threaded motor-driven drive gear which is mounted for rotation on the backplate. Because a portion of the damper assembly is splined, the damper assembly cannot rotate and is driven axially within the valve by the rotation of the drive motor and drive gear.

Abstract: An air valve actuated by an electric motor has a cylindrical inlet section. The inlet section defines a seating surface upstream of which is a support grid. A backplate to which the actuating motor is mounted is supported by a plurality of rods that extend downstream of the inlet section. A damper assembly includes a generally planar damper mounted for movement axial of the inlet section. The damper assembly includes a splined rod which extends upstream of the damper and into a cooperating spline in the support grid. A threaded spindle extends downstream of the damper plate through a cooperatively threaded motor-driven drive gear which is mounted for rotation on the backplate. Because a portion of the damper assembly is splined, the damper assembly cannot rotate and is driven axially within the valve by the rotation of the drive motor and drive gear.

Abstract: A normally closed pneumatically actuated air valve for use in a variable air volume air distribution system has a unitary inlet section which supports a damper assembly and actuator through a support grid disposed in the inlet section. The damper assembly is mounted for axial movement, on a fixed spindle and guide piston, under the impetus of the expansion of a pressure chamber defined by a portion of the damper assembly and a diaphragm which conformably surrounds the guide piston. A biasing spring acts on a surface of the fixed guide piston and on the damper assembly to bias the damper assembly toward a seating surface of the inlet section.

Abstract: A normally open pneumatic air control valve includes an inlet section which defines a seating surface and a support grid. A support plate, located downstream of the inlet section, is itself supported by a plurality of rods extending from the inlet section. A damper assembly is disposed for movement axial of the inlet section and is supported for such movement between the inlet section support grid and the downstream support plate. The damper assembly is actuated by the admission of a pressurized gas to a chamber cooperatively defined by a housing fixed to the support plate and a diaphragm disposed therein. A spring acts on the fixed grid support of the inlet section and on the damper assembly to urge the damper assembly away from the inlet section so that the valve is biased to the open position.

Abstract: Pressurized control signal apparatus is disclosed, which being supplied with air from a source of variable pressure, is operative to produce a control signal essentially independent of variations in the supply pressure. In one aspect of the invention, the control signal is amplified in volume of flow; in another, it is generated in response to temperature. The apparatus is specifically adapted to effect regulation of air flow in a variable air volume (VAV) temperature conditioning system in response to temperature in a conditioned zone, wherein the supply air for the apparatus is derived from a temperature conditioned air distribution duct of the VAV system.

Abstract: Pressurized control signal apparatus is disclosed, which being supplied with air from a source of variable pressure, is operative to produce a control signal essentially independent of variations in the supply pressure. In one aspect of the invention, the control signal is amplified in volume of flow; in another, it is generated in response to temperature. The apparatus is specifically adapted to effect regulation of air flow in a variable air volume (VAV) temperature conditioning system in response to temperature in a conditioned zone, wherein the supply air for the apparatus is derived from a temperature conditioned air distribution duct of the VAV system.