DAVID N SHAW
Engineering in Teaticket, MA
License number
Massachusetts 23756
Issued Date
Oct 23, 1970
Expiration Date
Jun 30, 2014
Type
Mechanical Engineer
Address
Address
Teaticket, MA 02536
Professional information
Oil Balance System And Method For Compressors Connected In Series
US Patent:
7651322, Jan 26, 2010
Filed:
Dec 7, 2007
Appl. No.:
11/952366
Inventors:
David N. Shaw - East Falmouth MA, US
Assignee:
Hallowell International, LLC - Bangor ME
International Classification:
F04B 39/04, F25B 43/02
US Classification:
417228, 417902, 62 84, 62193
Abstract:
A compressor system includes a first compressor, which has a first low side oil sump, in a first shell and a second compressor, which has a second low side oil sump, in a second shell. The first and second compressors are connected in series. There is an oil transfer conduit connected between the first low side sump of the first compressor and the second low side sump of the second compressor. The system also includes a normally open check valve in the oil transfer conduit. A method for effecting oil balance in a compressor system, the method includes establishing a first compressor in a first shell having a first low side oil sump and establishing a second compressor in a second shell having a second low side oil sump. The first and second compressors are connected in series. The method also includes positioning an oil transfer conduit between the first low side sump and the second low side sump and positioning a normally open check valve in the oil transfer conduit.
Oil Balance System And Method For Compressors
US Patent:
7712329, May 11, 2010
Filed:
Sep 27, 2005
Appl. No.:
11/664956
Inventors:
David Shaw - East Falmouth MA, US
International Classification:
F25B 43/02
US Classification:
62470, 62471, 62468, 62 84, 62510
Abstract:
A compressor system includes a first compressor, which has a first low side oil sump, in a first shell and a second compressor, which has a second low side oil sump, in a second shell. The first and second compressors are connected in series. There is an oil transfer conduit connected between the first low side sump of the first compressor and the second low side sump of the second compressor. The system also includes a normally open check valve in the oil transfer conduit. A method for effecting oil balance in a compressor system, the method includes establishing a first compressor in a first shell having a first low side oil sump and establishing a second compressor in a second shell having a second low side oil sump. The first and second compressors are connected in series. The method also includes positioning an oil transfer conduit between the first low side sump and the second low side sump and positioning a normally open check valve in the oil transfer conduit.
Oil Balance System And Method For Compressors Connected In Series
US Patent:
2006007, Apr 6, 2006
Filed:
Oct 6, 2004
Appl. No.:
10/959254
Inventors:
David Shaw - East Falmouth MA, US
International Classification:
F04B 3/00, F04B 5/00
US Classification:
417245000, 417244000
Abstract:
A compressor system includes a first compressor, which has a first low side oil sump, in a first shell and a second compressor, which has a second low side oil sump, in a second shell. The first and second compressors are connected in series. There is an oil transfer conduit connected between the first low side sump of the first compressor and the second low side sump of the second compressor. The system also includes a normally open check valve in the oil transfer conduit. A method for effecting oil balance in a compressor system, the method includes establishing a first compressor in a first shell having a first low side oil sump and establishing a second compressor in a second shell having a second low side oil sump. The first and second compressors are connected in series. The method also includes positioning an oil transfer conduit between the first low side sump and the second low side sump and positioning a normally open check valve in the oil transfer conduit.
Modular Multi-Rotor Compressor And Method Of Manufacture
US Patent:
7980836, Jul 19, 2011
Filed:
Jun 6, 2008
Appl. No.:
12/134389
Inventors:
David N. Shaw - East Falmouth MA, US
International Classification:
F04C 18/00, F04C 2/00
US Classification:
418197, 418190, 4182013
Abstract:
A multi-rotor compressor and method of manufacturing is provided. The compressor includes a housing with a plurality of identical planet rotors. The planet rotors are equally spaced apart at a fixed distance from a centerline. A single sun rotor is provided that is disposed to cooperate with the plurality of identical planet rotors in the compression of gas. The number and radial spacing of the plurality of identical planet rotors about said single sun rotor may be arranged in different configurations to change an output capacity parameter for said compressor.
Boosted Air Source Heat Pump
US Patent:
6931871, Aug 23, 2005
Filed:
Aug 27, 2003
Appl. No.:
10/650366
Inventors:
David N. Shaw - East Falmouth MA, US
David S. Fishman - West Hartford CT, US
David S. Fishman - West Hartford CT, US
Assignee:
Shaw Engineering Associates, LLC - Rocky Hill CT
International Classification:
F25B049/00
US Classification:
62228, 623246, 622283
Abstract:
A heat pump system is presented having a primary compressor, a booster compressor, a multi-step thermostat, an indoor coil, an outdoor coil, a refrigerant flow conduit connecting these elements is a closed loop system, and at least one pressure sensor positioned to always sense the refrigerant system low side pressure, which is commensurate with outdoor ambient air temperature in all heating modes of operation. The pressure sensor functions as an override and safety control to prevent or permit operation of the compressors, and also other system components, depending on outside air temperature. The primary compressor is preferably a multi-capacity compressor. A defrost energy transfer fluid is used in a defrost cycle.
Defrost System And Method For Heat Pumps
US Patent:
2010022, Sep 16, 2010
Filed:
Mar 10, 2009
Appl. No.:
12/401136
Inventors:
David N. Shaw - East Falmouth MA, US
Assignee:
SHAW ENGINEERING ASSOCIATES, LLC - East Falmouth MA
HALLOWELL INTERNATIONAL, LLC - Bangor ME
HALLOWELL INTERNATIONAL, LLC - Bangor ME
International Classification:
F25D 21/06, F25D 27/00, F25D 23/00, F25B 13/00
US Classification:
62 81, 62151, 62264, 62275, 622591, 623245, 623246
Abstract:
A system and method for defrosting an air source heat pump are presented. A defrost conduit extends from the discharge from a system compressor to the outdoor coil. The defrost conduit includes a normally closed defrost valve. When the need for defrost exists, the defrost valve is opened, and warm refrigerant is delivered from the compressor discharge to the outdoor coil to effect defrost of the outdoor coil.
Oil Balance System And Method For Compressors Connected In Series
US Patent:
8075283, Dec 13, 2011
Filed:
Jun 20, 2008
Appl. No.:
12/143172
Inventors:
David N. Shaw - East Falmouth MA, US
Assignee:
Hallowell International, LLC - Bangor ME
International Classification:
F04B 39/04, F04B 39/06
US Classification:
417228
Abstract:
A compressor system includes a first compressor, which has a first low side oil sump, in a first shell and a second compressor, which has a second low side oil sump, in a second shell. The first and second compressors are connected in series. There is an oil transfer conduit connected between the first low side sump of the first compressor and the second low side sump of the second compressor. The system also includes a normally open check valve in the oil transfer conduit. Additionally, a bleed is provided to effect oil transfer via the oil transfer conduit when the normally open valve is closed.
Boosted Air Source Heat Pump
US Patent:
RE39625, May 15, 2007
Filed:
Aug 15, 2003
Appl. No.:
10/641999
Inventors:
David N. Shaw - East Falmouth MA, US
Assignee:
Hallowell International, LLC - Bangor ME
International Classification:
F25B 13/00
US Classification:
62117, 62160, 621961, 622285, 237 2 B
Abstract:
A boosted source heat pump (BSHP) is presented having a primary compressor, a booster compressor, an economizer, and a lubricant management system. At least the primary compressor is a twin-single compressor. The lubricant management system includes traps to prevent migration of lubricant to a non-operating compressor, and aspiration tubes from the sump to the low pressure intake zone to each compressor.
Heat Pump Apparatus And Method
US Patent:
2008017, Jul 24, 2008
Filed:
Jan 19, 2007
Appl. No.:
11/624743
Inventors:
David N. Shaw - East Falmouth MA, US
Assignee:
HALLOWELL INTERNATIONAL, LLC - Bangor ME
International Classification:
F25B 13/00
US Classification:
62160, 62510
Abstract:
A heat pump system and method is presented having a primary compressor, a booster compressor, an economizer, a microprocessor, an air temperature sensor, and a temperature sensor for sensing a temperature commensurate with the boiling temperature of refrigerant in the outside coil. The microprocessor effects controlled operation of the primary compressor, the booster compressor and the economizer when a thermostat calls for heat and in accordance with predetermined ranges of air temperature. The microprocessor calculates a defrost trigger temperature, and defrost operation is initiated when the sensed refrigerant boiling temperature is lower than the trigger temperature for a period of time.