# US 11,298,652 B2 · Hybrid low dew point compressed air dryer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,298,652 B2 - Document ID: US11298652B2 - Status: Granted - Kind: B2 - Application number: 16/834,652 - Filed: 2020-03-30 - Published: 2020-07-16 - Granted: 2022-04-12 - Earliest claimed: 2018-01-17 - Assignees: Ingersoll-Rand Industrial U.S., Inc. - Applicants: Ingersoll-Rand Industrial U.S., Inc. - Inventors: Charles John Bergh - Web page: https://patentgrep.com/patent/US11298652B2 ## CPC - B01D 53/261: {by adsorption} - B01D 53/0446: {Means for feeding or distributing gases} - B01D 53/0454: {Controlling adsorption (controlling temperature swing adsorption B01D53/0462, controlling pressure swing adsorption B01D53/047)} - B01D 53/06: with moving adsorbents, e.g. rotating beds {(B01D53/025 takes precedence)} - B01D 53/265: {by refrigeration (condensation)} - F24F 3/1429: {alternatively operating a heat exchanger in an absorbing/adsorbing mode and a heat exchanger in a regeneration mode} - B01D 2257/80: Water - B01D 2259/4009: using hot gas - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) ## Abstract The present disclosure is directed to a dryer system for drying compressed gas discharged from a compressor. The dryer system includes a refrigeration drying system operable for removing moisture from the compressed gas and a desiccant drying system with a desiccant wheel located in series downstream of the refrigeration drying system operable for removing additional moisture from the compressed gas. ## Claims ### Claim 1 A dryer system for drying a pre-compressed fluid comprising: a fluid compressor operable to compress a working fluid, the working fluid compressed by the fluid compressor including liquid particles condensed in a gas flow; a dryer system for drying the compressed working fluid in fluid communication with the compressor, the dryer system comprising: a first heat exchanger having a pre-cooler portion for pre-cooling the compressed working fluid, a refrigeration drying system including: a second heat exchanger located downstream from the first heat exchanger, the second heat exchanger having a cooler for further reducing the temperature of the compressed working fluid, and a coalescing filter located downstream from the second heat exchanger, operable for removing moisture from the working fluid; and a desiccant drying system located downstream of the refrigeration drying system, the desiccant drying system operable for removing additional moisture from the working fluid. ### Claim 2 (depends on 1) The system of claim 1, wherein the desiccant drying system includes a desiccant wheel. ### Claim 3 (depends on 2) The system of claim 2, wherein the working fluid downstream of the refrigeration drying system is split into a first flow stream and a second flow stream. ### Claim 4 (depends on 3) The system of claim 3, wherein additional moisture is removed from the first flow stream in the desiccant wheel. ### Claim 5 (depends on 3) The system of claim 3, wherein the second flow stream regenerates the desiccant wheel after being heated by hot discharge gas from a refrigeration compressor. ### Claim 6 (depends on 3) The system of claim 3, wherein the second flow stream merges with the working fluid compressed by the fluid compressor after exiting the desiccant wheel. ### Claim 7 (depends on 6) The system of claim 6, wherein the second flow stream merges with the working fluid compressed by the fluid compressor between the precooler and a refrigerant evaporator after exiting the desiccant wheel. ### Claim 8 (depends on 3) The system of claim 3, wherein the second flow stream merges with the working fluid compressed by the fluid compressor upstream of the coalescing filter such that the coalescing filter filters liquid particles from the gas flow of the working fluid after the second flow stream is merged with the working fluid. ### Claim 9 A gas dryer for a pre-compressed gas comprising: a primary gas flow path extending through a refrigerant dryer circuit and subsequently through a desiccant dryer circuit; a coalescing filter located in the refrigerant dryer circuit configured to remove moisture from a gas in the primary gas flow path prior to entering the desiccant dryer circuit; a secondary gas flow path split off from the primary gas flow path downstream of the coalescing filter and upstream of the desiccant dryer circuit; a desiccant wheel positioned in the desiccant dryer circuit configured to remove additional moisture from the gas in the primary gas flow path; and a regeneration flow path extending through the desiccant wheel, the regeneration flow path in fluid communication with the secondary gas flow path. ### Claim 10 (depends on 9) The gas dryer of claim 9, further comprising: a moisture separator positioned in the refrigerant dryer circuit and configured to remove moisture from the gas in the primary gas flow path. ### Claim 11 (depends on 10) The gas dryer of claim 10, wherein the coalescing filter is positioned downstream of the moisture separator. ### Claim 12 (depends on 10) The gas dryer of claim 10 further comprising at least one drain valve in fluid communication with the moisture separator and the coalescing filter. ### Claim 13 (depends on 9) The gas dryer of claim 9 further comprising a regeneration blower operably connected with the secondary gas flow path. ### Claim 14 (depends on 9) The gas dryer of claim 9 further comprising a regeneration gas heater positioned in the secondary gas flow path upstream of the desiccant wheel. ### Claim 15 (depends on 9) The gas dryer of claim 9, wherein secondary gas flow path includes an outlet downstream of the desiccant wheel connected to the primary gas flow path upstream of an evaporator in the refrigerant drying circuit. ### Claim 16 A method of drying a pre-compressed working fluid comprising: transporting a primary flow stream of pressurized working fluid discharged from a compression device through a primary flow path, the primary flow path extending through a refrigerant dryer circuit; filtering from the pressurized working fluid, in a coalescing filter located in the refrigerant dryer circuit, at least one of solid particles and liquid particles condensed in the pressurized working fluid; transporting the primary flow stream through a desiccant dryer circuit; and separating moisture from the pressurized working fluid in a desiccant wheel located in the desiccant dryer circuit, downstream of the coalescing filter. ### Claim 17 (depends on 16) The method of claim 16, further comprising separating the pressurized working fluid from the primary flow stream into first and second flow streams upstream of the desiccant wheel and downstream of the coalescing filter. ### Claim 18 (depends on 17) The method of claim 17, further comprising: flowing the first flow stream through the desiccant wheel; drying the pressurized working fluid in the first flow stream; and wherein a pressure dew point temperature of the pressurized working fluid downstream of the desiccant wheel is below 32 degrees F. and an actual temperature is above 32 degrees F. ### Claim 19 (depends on 17) The method of claim 17, further comprising: flowing the second flow stream through the desiccant wheel; regenerating the desiccant wheel by removing moisture with the pressurized working fluid in the second flow stream; merging the second flow stream with the primary flow stream upstream of an evaporator. ### Claim 20 (depends on 16) The method of claim 16, further comprising: cooling the pressurized working fluid in a precooler heat exchanger; chilling the pressurized working fluid in a refrigerant evaporator located in the refrigerant dryer circuit; separating moisture from the pressurized working fluid in a moisture separator located downstream of the precooler heat exchanger; and reheating the pressurized working fluid prior to delivery to an end user.