Patent Grant
10156233
Pressurized gases, such as, air, helium, nitrogen, halogen, and the like, have many uses in industry. In general, pressurized gas systems work by providing a receiver, also commonly known as a tank, canister, reservoir, etc., which receives and stores the compressed gas for use at a later time. A discharge on the receiver is accessed to disburse some of the compressed gas from the receiver, which correspondingly reduces the pressure of the gas contained in the receiver.
A gas compressor is a mechanical device used to recharge or pressurize the receiver after a determined volume of pressurized gas has been discharged from the receiver or the receiver pressure has decreased to a predetermined value. The gas compressor is a mechanical device that increases the pressure of gas by reducing its volume. Generically, the term gas compressor and air compressor may be used interchangeably herein. Many gas compressors draw gas from the atmosphere, in other words, air. In any event, a volume of air is inducted into the compressor and then mechanically compressed into a smaller volume in the compression chamber. The compressed air is discharged from the compressor and stored in an air receiver. Compressed air is used for a wide range of applications. As the air is used from the receiver, the compressor needs to compress more air to keep up with the demand. A common method of driving an air compressor is an electric motor. The idea is to have compressed air on demand, but to limit the number of times the motor must start the compressor in a given time period, to prevent motor burnout.
Gas, or air, compressors use a variety of devices to control the operation of the compressor. The control type employed is determined by how frequent there is a demand for compressed air. A compressor that encounters varying periods of light and heavy usage, can be equipped with two, or more, control types, which is generically known in the industry as dual controls. The operator can manually switch between each control type, depending on the demand for compressed air.
As can be appreciated, the dual control compressor for a pressurized air system requires a number of parts, connections, and space to be set up and function properly. Thus, against this background, an improved dual control for a compressor is needed.
One aspect of the present disclosure relates to a gas compressor system that includes a gas receiver, a compressor, a motor, and a continuous run controller. The gas receiver is configured to store a volume of gas. The compressor is coupled in flow communication with the gas receiver and includes a lubrication system and a suction valve unloader. The motor is operable to power the compressor. The continuous run controller is coupled in flow communication with the gas receiver and the compressor. The continuous run controller includes an integrated housing, a pilot valve, and a hydraulic unloader valve. The housing includes an inlet port in flow communication with the gas receiver, an outlet port in flow communication with the suction valve unloader, and at least first and second component ports. The pilot valve is mounted in the first component port and arranged in flow communication with the inlet and outlet ports. The hydraulic unloader valve is mounted in the second component port and arranged in flow communication with the inlet and outlet ports and the lubrication system. When gas pressure in the gas receiver is below a threshold level, the pilot valve closes to reduce pressure supplied to the suction valve unloader thereby allowing the compressor to generate compressed air. When gas pressure in the gas receiver is above a threshold level, the pilot valve opens to increase pressure supplied to the suction valve unloader thereby restricting the compressor from generating compressed air. When oil pressure in the lubrication system is above a threshold level, the hydraulic unloader valve closes to reduce pressure to the suction valve unloader thereby allowing the compressor to generate compressed air. When oil pressure in the lubrication system is below a threshold level, the hydraulic unloader valve opens to increase pressure to the suction valve unloader thereby restricting the compressor from generating compressed air.
The integrated housing may also include a third component port, and the continuous run controller may also include a check valve mounted in the third component port and arranged in flow communication between the outlet port and the pilot valve, and positioned between the outlet port and the hydraulic unloader valve. The check valve may include a check valve inlet in flow communication with the pilot valve and the hydraulic unloader valve, a check valve seat, a disc movable between opened and closed positions relative to the check valve seat, and a check valve outlet in flow communication with the outlet port. The hydraulic unloader valve may include a hydraulic valve inlet in flow communication with the inlet port, a hydraulic valve seat, a plunger operable between opened and closed positions relative to the hydraulic valve seat, a plunger spring operable to bias the plunger into the opened position, a lubrication system port in fluid communication with the lubrication system, and a hydraulic valve outlet in flow communication with the outlet port.
The hydraulic unloader valve may also include a diaphragm that includes a first side and a second side, the first side operably coupled to the plunger and the second side in fluid communication with oil from the lubrication system such that oil pressure in the lubrication system moves the diaphragm against biasing forces of the plunger spring to move the plunger into the closed position. The pilot valve may include a pilot valve inlet in flow communication with the inlet port, a pilot valve seat, a ball operable between opened and closed positions relative to the pilot valve seat, a pilot valve spring operable to bias the ball into the closed position, and a pilot valve outlet in flow communication with the outlet port. The gas compressor system may further include a pressure switch operably coupled to the gas receiver and the motor, wherein the pressure switch is operable to cause the motor to start when pressure in the gas receiver drops below a first pressure level and to stop the motor when pressure in the gas receiver exceeds a second pressure level. The integrated housing may include a single, unitary piece.
Another aspect of the present disclosure relates to a continuous run controller for a gas compressor system. The continuous run controller includes an integrated housing, a pilot valve, and a hydraulic unloader valve. The integrated housing includes an inlet port, an outlet port, and at least first and second component ports. The pilot valve is mounted in the first component port and arranged in flow communication with the inlet and outlet ports. The hydraulic unloader valve is mounted in the second component port and arranged in flow communication with the inlet and outlet ports and a lubrication system of the gas compressor system. When gas pressure at the inlet port is below a threshold level, the pilot valve closes to reduce gas pressure available at the outlet port. When gas pressure at the inlet port is above a threshold level, the pilot valve opens to increase gas pressure available at the outlet port. When oil pressure available to the hydraulic unloader valve is above a threshold level, the hydraulic unloader valve closes to reduce gas pressure available at the outlet port. When oil pressure available to the hydraulic unloader valve is below a threshold level, the hydraulic unloader valve opens to increase gas pressure available at the outlet port. Changes in gas pressure at the outlet port causes loading and unloading of a suction valve of a compressor of the gas compressor system.
The integrated housing may further include a third component port, and the continuous run controller may further include a check valve mounted in the third component port and arranged in flow communication between the outlet port and the pilot valve, and between the outlet port and the hydraulic unloader valve. The check valve may include at least one check valve inlet in flow communication with the pilot valve and the hydraulic unloader valve, a check valve seat, a disc movable between opened and closed positions relative to the check valve seat, and a check valve outlet in flow communication with the outlet port. The hydraulic unloader valve may include an hydraulic unloader valve inlet in flow communication with the inlet port, a hydraulic valve seat, a plunger operable between opened and closed positions relative to the hydraulic valve seat, a plunger spring operable to bias the plunger into the opened position, a lubrication system port in fluid communication with the lubrication system, and a hydraulic valve outlet in flow communication with the outlet port.
The hydraulic unloader valve of the continuous run controller further comprises a diaphragm, the diaphragm comprising a first side and a second side, the first side operably coupled to the plunger and the second side in fluid communication with oil from the lubrication system such that oil pressure in the lubrication system causes movement of the diaphragm that overcomes the plunger spring to move the plunger into the closed position.
The pilot valve may include a pilot valve inlet in flow communication with the inlet port, a pilot valve seat, a ball operable between opened and closed positions relative to the pilot valve seat, a pilot valve spring operable to bias the ball into the closed position, and a pilot valve outlet in flow communication with the outlet port. The continuous run controller may also include a pressure switch operably coupled to a gas receiver and the motor of the gas compressor system, wherein the pressure switch is operable to cause the motor to start when pressure in the gas receiver drops below a first pressure level and to stop the motor when pressure in the gas receiver exceeds a second pressure level. The integrated housing may be formed as a single, unitary piece.
Another aspect of the present disclosure relates to a method of controlling operation of a compressor of a gas compressor system. The method includes providing a gas receiver, a motor, a compressor coupled in flow communication with the gas receiver, and a continuous run controller coupled in flow communication with the gas receiver and the compressor, the compressor comprising a lubrication system and a suction valve unloader. The continuous run controller includes an integrated housing having inlet and outlet ports, a pilot valve mounted in a first component port of the housing and arranged in flow communication with the inlet and outlet ports, and a hydraulic unloader valve mounted in a second component portion of the housing and arranged in flow communication with the inlet and outlet ports and the lubrication system. The housing has an inlet port in flow communication with the gas receiver and an outlet port in flow communication with the suction valve unloader. The method further includes closing the pilot valve when gas pressure in the gas receiver is below a threshold level to reduce pressure supplied to the suction valve unloader thereby allowing the compressor to generate compressed air, opening the pilot valve when gas pressure in the gas receiver is above a threshold level to increase pressure supplied to the suction valve unloader thereby restricting the compressor from generating compressed air, closing the hydraulic unloader valve when oil pressure in the lubrication system is above a threshold level to reduce pressure to the suction valve unloader thereby allowing the compressor to generate compressed air, and opening the hydraulic unloader valve when oil pressure in the lubrication system is below a threshold level to increase pressure to the suction valve unloader thereby restricting the compressor from generating compressed air.
Closing and opening the pilot valve may include moving a pilot valve ball relative to a seat of the pilot valve. Opening and closing the hydraulic unloader valve may include moving a diaphragm of the hydraulic unloader valve. The method may also include providing a check valve mounted in a third component port of the housing and in flow communication between the outlet port and the pilot and hydraulic unloader valves.
The accompanying drawings illustrate various embodiments of the present method and system and are a part of the specification. The illustrated embodiments are merely examples of the present system and method and do not limit the scope thereof.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.
The present disclosure is directed to compressor systems such as an air or gas compressor system. The terms “air” and “gas” are used interchangeably throughout the present disclosure. In particular, the present disclosure is directed to controls for a compressed air system. The compressed air system may include two different modes. One mode may be particularly useful during periods of light usage of the compressor system. The other mode may be particularly useful for heavy usage of the compressor. Various aspects of the present disclosure are focused on the second mode, and may provide automatic control of the compressor system to generate compressed air.
Existing compressor systems may utilize a plurality of valve structures interconnected with separate hoses or lines as part of a control system that is operable during heavy usage of the compressor system. One aspect of the present disclosure is directed to integration of the plurality of valve members into a single, integrated housing, which may have a number of advantages over existing designs. For example, the single, integrated housing may provide easier assembly because fewer parts are required and the assembly is consolidated at a single location. Another advantage may relate to faster responses to pressure changes because of the relative close proximity between the valves and the air channels formed in the housing that interconnect the valves. A further example may be the reduced probability for leaks because fewer connections are required when using an single, integrated housing. Maintenance costs and maintenance time may be reduced because fewer parts are required and many of the parts are enclosed internally within the housing and protected from the environment. Generally, less material may be required and less material handling is necessary in order to manufacture a single, integrated housing as compared to other designs. The single, integrated housing may provide a substantially more compact structure that requires less space for shipping, retail display, and in-the-field use. Further advantages may be apparent in view of the descriptions provided below with reference to the attached figures and in comparing existing designs to the new control features disclosed herein.
Referring now to
During periods of relatively low usage or demand, the compressor system 10 is controlled by pressure switch 18. Pressure switch 18, which may alternatively be a conventional pressure sensor, monitors the pressure in air receiver 12. Release of air from air receiver 12 through a discharge 13 causes the pressure to decrease within air receiver 12. Pressure switch 18 has a low pressure threshold that causes pressure switch 18 to change state and send a signal S to switch controller 22 to start motor 14. Motor 14 starts and, as explained above, operates compressor 16 to inject pressurized air into air receiver 12, thus causing air pressure to increase within air receiver 12. When the air pressure exceeds a high pressure threshold, pressure switch 18 sends a signal S to switch controller 22 to stop motor 14. Typically, the low pressure threshold is below the high pressure threshold to minimize on/off cycles of the motor 14. Alternatively, the low pressure threshold and high pressure threshold may be set at substantially the same level.
As may be appreciated, high demands for pressurized air from air receiver 12 will cause motor 14 to cycle on and off frequently. This frequent on and off cycling should be avoided if possible in order minimize wear on motor 14 and compressor 16. Motor 14 may be continuously running during periods of high demand on the compressor system 10 to avoid cycling motor 14 on and off. However, continually providing pressurized air to air receiver 12 may cause an over-pressure condition that results in automatic opening of a pressure relief valve (not shown). Cycling of the pressure relief valve should also be avoided in order to minimize wear and possible failure of the pressure relief valve. In order to address these issues, compressor system 10 may be provided with a continuous run control scheme using components of controller assembly 20.
Pilot valve 34 may be used in combination with suction valve unloader assembly 24 to control when compressor 16 is turned on and off while motor 14 continues to run. Once started, motor 14 runs continuously until manually stopped. Compressor 16 will compress air until the demand within air receiver 12 is satisfied. At that point, pressure will open pilot valve 34, thus allowing air pressure to pass to suction valve unloader assembly 24. Suction valve unloader assembly 24 unseats suction valve 26 of compressor 16, which inhibits the compressor 16 from drawing air into its compressor chamber (not shown) to create compressed air. In other words, motor 14 continues to run, but compressor 16 stops compressing air. Compressor 16 operates unloaded until the air receiver 12 pressure drops to below a low threshold level. At that point, pilot valve 34 closes and vents the pressure to the suction valve unloader assembly 24 to release pressure from suction valve unloader assembly 24, thereby seating suction valve 26. The compressor 16 is then able to draw air into the compression chamber of compressor 16 such that compressor 16 is again permitted to compress air. The compressed air is delivered to and stored within air receiver 12. This control method allows the compressor 16 to always be ready to compress air while avoiding cycling or straining motor 14 with repeated starting and stopping.
Operation of compressor 16 requires lubrication, typically in the form of oil, to allow the mechanical parts to move with limited friction. Compressor 16 may include hydraulic unloader valve 30 to protect compressor 16 from low oil pressure situations. Hydraulic unloader valve 30 receives an oil pressure input from lubrication system 38 and an air pressure input from air receiver 12. At startup of compressor 16, no oil pressure is typically present in lubrication system 38 of compressor 16. In this state, pressurized air within air receiver 12 causes hydraulic unloader valve 30 to open and allows pressurized air to pass to suction valve unloader assembly 24. Suction valve unloader assembly 24 unseats the suction valve 26 of compressor 16, as explained above. This causes compressor 16 to start up without a load, which allows for oil pressure in the lubrication system 38 to build up before compressor 16 is allowed to generate compressed air. This scenario is commonly referred to as a loadless start. As the oil pressure builds up above a pressure set point within lubrication system 38, the oil pressure from lubrication system 38 overcomes the air pressure force and causes hydraulic unloader valve 30 to close. The closing of the hydraulic unloader valve 30 vents the pressurized air to the suction valve unloader assembly 24, which causes the suction valve 26 to seal and the compressor 16 is loaded only subsequent to the lubrication system being brought up to operation oil pressure. This allows compressor 16 to start compressing air, and the compressed air is delivered to air receiver 12.
Hydraulic unloader valve 30 also protects compressor 16 in the event of an unexpected, potentially damaging oil pressure drop during operation. If the oil pressure drops for any reason, hydraulic unloader valve 30 opens, compressed air is delivered to suction valve unloader assembly 24, suction valve 26 opens, and compressor 16 is unloaded to stop generation of compressed air.
Check valve 32 operates to control air flow from hydraulic unloader valve 30 and pilot valve 34 in a single direction of flow towards suction valve unloader assembly 24. Check valve 32 prevents backflow of air between hydraulic unloader valve 30 and pilot valve 34.
As shown in
Many of the disadvantages of compressor system 10 may be addressed by an improved compressor system and related controller assembly 120 described with reference to
The controller assembly 120 may be particularly useful for a continuously running motor associated with a compressor, such as the motor 14 described above with reference to
Housing 136 provides first, second and third component seats 140, 142, 144, an inlet port 146, an outlet port 148, and a plurality of internal channels C1, C1A, C1B, C2, C3, and C4. Lines L2, L5 may be connected to and/or in flow communication with the inlet and outlet ports 146, 148. Line L3 may be connected to and/or in flow communication with hydraulic unloader valve 130. Line L2 is in flow communication with air receiver 12. Line L3 is in flow communication with lubrication system 38.
Hydraulic unloader valve 130, check valve 132, and pilot valve 134 may be mounted in the first, second and third component seats 140, 142, 144, respectively, with conventional threaded connections. Alternatively, welds, adhesives, or other permanent connection methods, as well as other releasable connection methods may be used to secure valves 130, 132, 134 within seats 140, 142, 144, respectively.
Channel C1 is connected in flow communication with inlet port 146, and hence a flow of air F from air receiver 12 via line L1. Channel C1 is pressurized to approximately the same pressure as the pressurized air receiver 12. Channels C1A and C1B are arranged in flow communication with channel C1, and are also pressurized to approximately the same pressure as air receiver 12. Channel C2 provides flow communication between an outlet of hydraulic unloader valve 130 and an inlet of check valve 132. Channel C3 provides flow communication between an outlet of pilot valve 134 and an inlet of check valve 132. Channel C4 provides flow communication from check valve 132 to the outlet port 148 and line L5. Line L5 is connected in flow communication with suction valve unloader assembly 24.
Hydraulic unloader valve 130 includes a plunger 150, a spring 152, and/or a discharge (not shown), an oil inlet 156, a diaphragm 158, and a seat 159. Spring 152 biases plunger 150 away from seat 159. Further, air pressure within channel C1B moves plunger 150 away from seat 159. Oil pressure from lubrication system 38 builds within oil inlet 156 as a flow of oil O to move diaphragm 158 against the biasing forces of spring 152 and the air pressure within channel C1B to force plunger 150 against seat 159 to close hydraulic unloader valve 130 (see
Check valve 132 includes a disc 170 that moves within seat 142 to control air flow into channel C4 and out through outlet port 148. In a first position (see
Pilot valve 134 includes a valve seat 160, a ball 162, a valve stem 164, a spring 166, and an air vent port 168. Ball 162 is biased into a closed position in contact with valve seat 160 by spring 166.
Pilot valve 134 typically moves into the open position of
In alternative embodiments, controller assembly 120 does not include a separate check valve 132. For example, housing 136 may be void of the separate component seat 142 and the outlets of both of the hydraulic unloader valve 130 and pilot valve 134 may be directly connected to outlet port 148.
Referring now to
According to method 200, the compressor remains unloaded while the motor runs until the lubrication system is fully pressurized. Once the lubrication system is pressurized, the hydraulic loader valve closes to stop the flow of pressurized air to the suction valve unloader assembly, thereby permitting the compressor to begin running to generate compressed air. The hydraulic unloader valve and pilot valve remain closed until pressure within the air receiver reaches a high pressure threshold. The high pressure threshold opens the pilot valve to permit a flow of pressurized air to be delivered to the suction valve unloader assembly, which causes the compressor to turn off while the motor continues running. The compressor remains in an off state until air from the air receiver is discharged to a point that the pressure condition in the air receiver reaches a low threshold condition. Once the low threshold pressure condition is met, the pilot valve again closes, which bleeds the pressurized air available to suction valve unloader assembly, and results in the compressor turning on again to generate compressed air.
The method 200 continues to cycle between blocks to 222 and 214 continually until an operator manually turns off the motor.
The controller assembly 120 described with reference to
As discussed above, the integrated housing 136 may provide a number of advantages as compared to a controller assembly having components that are interconnected with a plurality of separate lines and fittings. The internal channels C1-C4 may be sealed upon connection of the hydraulic unloader valve 130, check valve 132, pilot valve 134 and fittings for lines L2 and L5 at the inlet and outlet ports 146, 148 to housing 136. The channels C1-C4 are protected from environmental conditions. Further, the channels C1-C4 may be relatively small in size and short in length while still providing the desired flow communication between the inlet and outlet ports 146, 148. The smaller size and shorter length of channels C1-C4 as compared to the lines L2A, L2B, L4 and L6 of compressor system 10 described with reference to
Additionally, manufacture and assembly of controller assembly 120 may be simplified because of the reduced number of parts when using integrated housing 136. The cost of the controller assembly 120 may also be reduced because of the reduced number of parts and/or the reduced amount of material required. Furthermore, manufacturing and assembly, as well as maintenance, may be simplified because the housing 136 may be a more stable, easier to handle and maneuver component for connection of the various valves, lines, fittings, etc. as compared to the plurality of separate and freely moveable components, lines, hoses, fittings, etc. associated with controller assembly 20 of
The example controller assembly 120 shown with reference to
While the technology of the present application is described with respect to a dual control gas compressor, the technology disclosed herein may be applicable to other compressors. Moreover, the technology disclosed herein will be described with reference to certain exemplary embodiments. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments absent a specific indication that such an embodiment is preferred or advantageous over other embodiments. Moreover, in certain instances only a single “exemplary” embodiment is provided. A single example is not necessarily to be construed as the only embodiment. The detailed description includes specific details for the purpose of providing a thorough understanding of the technology of the present patent application. However, on reading the disclosure, it will be apparent to those skilled in the art that the technology of the present patent application may be practiced with or without these specific details. In some descriptions herein, generally understood structures and devices may be shown in block diagrams to aid in understanding the technology of the present patent application without obscuring the technology herein. In certain instances and examples herein, the term “coupled” or “in communication with” means connected using either a direct link or indirect data link as is generally understood in the art. Moreover, the connections may be wired or wireless, private or public networks, or the like.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 61/748,213, filed on 2 Jan. 2013, and entitled DUAL CONTROL VALVE FOR RECIPROCATING COMPRESSOR UNLOADER SYSTEM, the disclosure of which is incorporated, in its entirety, by reference. The technology of the present application relates generally to gas compressors and, more specifically, to dual control gas compressors.
| Number | Name | Date | Kind |
|---|---|---|---|
| 20030021703 | Wallis | Jan 2003 | A1 |
| 20040213679 | Cornwell | Oct 2004 | A1 |
| 20070056636 | Cornwell | Mar 2007 | A1 |
| 20130139535 | Nares | Jun 2013 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20180119690 A1 | May 2018 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61748213 | Jan 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14146593 | Jan 2014 | US |
| Child | 15799535 | US |
