Secondary airflow paths for air compressors

Patent metadata

Field	Value
Publication number	US-12410799-B2
Application number	US-202418627207-A
Country	US
Kind code	B2
Filing date	Apr 4, 2024
Priority date	Apr 5, 2023
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A secondary airflow path can be provided for a compressor of a compressor system. The secondary airflow path can provide pressurized air to a boost port in communication with a closed compression cell of the compressor.

First claim

The invention claimed is:

1. An air compression system comprising:
a separator tank;
a service air outlet that is in fluid communication with the separator tank to supply compressed service air for work operations;
a first compressor in fluid communication with the separator tank, the first compressor including:
a first rotor;
a second rotor meshed with the first rotor; and
a housing structure that defines:
an air inlet;
an air outlet;
a compression chamber that encloses the first and second rotors, the compression chamber including a radial cut-off arranged to successively close compression cells formed by the first and second rotors, during rotation of the first and second rotors, for compression of air within the compression cells and delivery of the compressed air from the compression cells to the air outlet; and
a boost port in fluid communication with the compression chamber to direct pressurized air into the compression cells downstream of the radial cut-off, the boost port being in communication with the compression chamber along an axial length of the radial cut-off; and

a second compressor arranged to provide the pressurized air to the boost port.

2. The air compression system of claim 1 , wherein the second compressor is an electrically powered compressor.

3. The air compression system of claim 1 , wherein the second compressor is a booster or a turbo-charger of an engine that powers the first compressor.

4. The air compression system of claim 1 , wherein the boost port is at an outlet for an oil passageway in communication with a gearbox of the first compressor.

5. The air compression system of claim 4 , further comprising:
a boost line that intersects the oil passageway to provide the pressurized air.

6. The air compression system of claim 1 , wherein the air inlet is open to atmospheric pressure.

7. The air compression system of claim 1 , wherein the boost port is at an upstream end of the compression chamber.

8. The air compression system of claim 1 , wherein the boost port is a first boost port and the air compression system further comprises:
a second boost port in fluid communication with the compression chamber to direct the pressurized air into the compression cells downstream of the radial cut-off.

9. The air compression system of claim 8 , wherein the second boost port is arranged downstream of the first boost port along the compression chamber.

10. The air compression system of claim 1 , wherein the second compressor is arranged to provide the pressurized air to the first compressor in parallel with flow through the air inlet.

11. The air compression system of claim 1 , wherein the boost port is spaced axially from the radial cut-off by less than or equal to 20% of an axial length of the compression chamber.

12. A method of operating an air compression system, the method comprising:
powering a compressor to receive air at an air inlet of a housing structure of the compressor, wherein powering the compressor includes powering rotation of a first rotor and a second rotor meshed with the first rotor within a compression chamber to successively close compression cells formed by the first and second rotors, for compression of air within the compression cells and delivery of the compressed air via an air outlet of the housing structure, to supply compressed service air for work operations;
pressurizing boost air using an auxiliary compressor separate from the compressor; and
providing the pressurized boost air to a boost port in fluid communication with the compression chamber downstream of a radial cut-off of the compression chamber, the boost port entering the compression chamber along an axial length of the radial cut-off.

13. The method of claim 12 , further comprising:
identifying, using one or more control devices, an increased demand for service air during operation of the compressor to supply the compressed service air;
wherein providing the pressurized boost air to the boost port includes opening a flow path for flow of the pressurized boost air to the boost port in response to identifying the increased demand for the service air.

14. The method of claim 13 , wherein the one or more control devices identify the increased demand for service air based on sensing one or more of a pressure, a temperature, a flow rate, or an operator use pattern of the air compression system.

15. An air compression system comprising:
an oil-flooded rotary screw compressor that includes:
a first rotor;
a second rotor meshed with the first rotor; and
a housing structure that defines:
an air inlet;
an air outlet;
a compression chamber that encloses the first and second rotors, the compression chamber including a radial cut-off arranged to successively close compression cells formed by the first and second rotors, during rotation of the first and second rotors, for compression of air within the compression cells and delivery of the compressed air from the compression cells to the air outlet; and
a boost port in fluid communication with the compression chamber to direct pressurized air into the compression cells downstream of the radial cut-off, the boost port being located along an axial length of the radial cut-off; and

a boost compressor that provides the pressurized air to the boost port.

16. The air compression system of claim 15 , wherein the boost compressor is one or more of: an electrically powered compressor, a booster of an engine arranged to power the oil-flooded rotary screw compressor, or a turbo-charger of the engine.

Assignees

• Doosan Bobcat North America Inc

Inventors

• Rowe David
• Diep Tuan

Classifications

• F04C29/026

  Lubricant separation · CPC title

• F04C23/02

  Pumps characterised by combination with, or adaptation to, specific driving engines or motors · CPC title

• F04C18/107

  with helical teeth · CPC title

• F04C18/084

  Toothed wheels · CPC title

• F04C18/082

  Details specially related to intermeshing engagement type pumps · CPC title