EP1288503A1

EP1288503A1 - Compressor apparatus

Info

Publication number: EP1288503A1
Application number: EP01307041A
Authority: EP
Inventors: Ming-Te Lu
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-08-17
Filing date: 2001-08-17
Publication date: 2003-03-05

Abstract

A compressor apparatus includes a compressor (100) with an intake pipe (102) and a discharge pipe (103), a plurality of branch pipes (104) that extend from and that are in fluid communication with the discharge pipe (103), and a plurality of chambers (131, 231, 331, 431, 531, 631) that are in fluid communication with the branch pipes (104), respectively. Each of the chambers (131, 231, 331, 431, 531, 631) is in fluid communication with the intake pipe (102) via a return flow pipe unit (20). A plurality of pressure sensors (141, 241) are disposed respectively at the chambers (131, 231, 331, 431, 531, 631), and are set respectively at different discharge pressures. When the fluid pressure in one of the chambers (131, 231, 331, 431, 531, 631) reaches the corresponding discharge pressure, the fluid flows from the one of the chambers (131, 231, 331, 431, 531, 631) into the intake pipe (102) via the corresponding return flow pipe unit (20) so as to return to the compressor (100) for performing further compression of the fluid. Each of the branch pipes (104) and the return flow pipe units (20) is equipped with a control valve unit (121, 211, 232) that is controlled by a control unit (7) so that the fluid can flow through the chambers (131, 231, 331, 431, 531, 631) in a sequence that increases in the magnitude of the discharge pressures.

Description

This invention relates to a fluid compressor, and more particularly to a compressor apparatus, which includes a single compressor and which can discharge a fluid at different pressures.
Referring to Fig. 1, a common two-stage reciprocating compressor 6 is shown to include a motor 61, which is provided with an output shaft 611 that has two eccentric shaft portions 621, 622. Two pistons 631, 632 are attached respectively and rotatably to the eccentric shaft portions 622, 621, and are movable within two cylinders 641, 642, respectively. An auxiliary plate 651 is disposed fixedly in the cylinders 641, 642, and is formed with four openings 653, 655, 660, 662. The cylinders 641, 642 define four volume- invariable chambers 652, 657, 659, 664 that are formed between the plate 651 and the end walls of the cylinders 641, 642, two volume- variable chambers 654, 661 that are formed between the plate 651 and the pistons 631, 632, and a discharge port 665 that is formed through the end wall of the cylinder 642. An inverted U-shaped tube 658 is fixed to the cylinders 641, 642, and is in fluid communication with the chambers 657, 659. Two one- way valves 656, 663 are disposed at the openings 655, 662, respectively. Air is introduced into the chamber 652, and is sucked into the chamber 654 via the opening 653 by moving the piston 631 downwardly. When the piston 631 moves upwardly, the air flows from the chamber 654 into the chamber 657 via the opening 655, and subsequently into the chamber 659 via the tube 658. Likewise, by moving the piston 632 reciprocally, the air can flow from the chamber 659 into the chamber 664 via the opening 660, the chamber 661 and the opening 662, thereby permitting discharge of the air through the port 665. Accordingly, the air can be compressed twice in the compressor 6. However, air is discharged from the compressor 6 at only one pressure, thereby limiting the applicable range of the compressor 6.
Referring to Fig. 2, a multi-stage axial-flow compressor 7 is shown to include a housing 71, a rotor 72, a plurality of rotating vanes 73 that are fixed to the rotor 72, and a plurality of guiding vanes 74 that are fixed to an inner surface of the housing 71. The rotating vanes 73 are staggered with the guiding vanes 74 so as to form an air passage therebetween, through which air can flow from the left end of the compressor 7 to the right end of the same. As such, the air is discharged from the right end of the compressor 7 at only one pressure.
Therefore, an object of this invention is to provide a compressor apparatus, which includes a single compressor that can recompress compressed fluid so as to discharge a fluid at different pressures, thereby increasing the applicable range.
According to this invention, a compressor apparatus includes a compressor with an intake pipe and a discharge pipe, a plurality of branch pipes that extend from and that are in fluid communication with the discharge pipe, and a plurality of chambers that are in fluid communication with the branch pipes, respectively. Each of the chambers is in fluid communication with the intake pipe via a return flow pipe unit. A plurality of pressure sensors are disposed respectively at the chambers, and are set respectively at different discharge pressures. When the fluid pressure in one of the chambers reaches the corresponding discharge pressure, the fluid flows from the one of the chambers into the intake pipe via the corresponding return flow pipe unit so as to return to the compressor for performing further compression of the fluid. Each of the branch pipes and the return flow pipe units is equipped with a control valve unit that is controlled by a control unit so that the fluid can flow through the chambers in a sequence that increases in the magnitude of the discharge pressures. As such, the fluid can be discharged from the chambers at the discharge pressures.
These and other features and advantages of this invention will become apparent in the following detailed description of a preferred embodiment of this invention, with reference to the accompanying drawings, in which:
Fig. 1 is a sectional view of a conventional two-stage reciprocating compressor;
Fig. 2 is a sectional view of a conventional axial-flow multi-stage compressor; and
Fig. 3 is a piping and instrument diagram of the preferred embodiment of a compressor apparatus according to this invention.
Referring to Fig. 3, the preferred embodiment of a compressor apparatus according to this invention is shown to include a compression unit 1, five recompression units 2, 3, 4, 5, 6, a control unit 7 and a common pressure-sensing unit 8.
The compression unit 1 includes a compressor 100, a cooler 101, an intake pipe 102 and a discharge pipe 103. The cooler 101 is disposed on the discharge pipe 103 so as to cool the fluid that flows from the compressor 100. The intake pipe 102 is used to supply the fluid into the compressor 100, and is equipped with a normal-closed control valve 111 and a one-way valve 112 for limiting fluid flow from the intake pipe 102 into the compressor 100. The discharge pipe 103 is in fluid communication with the compressor 100, and is provided with six branch pipes 104 that are in fluid communication with six chambers 131, 231, 331, 431, 531, 631, respectively. Each adjacent pair of the chambers 131, 231, 331, 431, 531, 631 are communicated fluidly with each other by a connecting pipe 9, which is equipped with a one-way valve 91. The valves 91 limit the fluid flow from the chamber 131 to the chamber 631 via the chambers 231, 331, 431, 531. Each of the branch pipes 104 is equipped with a normal-closed control valve 121 and a one-way valve 122 for limiting fluid flow from the respective branch pipe 104 into the corresponding chamber 131, 231, 331, 431, 531, 631. When the apparatus is powered, the control unit 7 opens the control valves 111, 121 of the compression unit 1 so as to permit the fluid flow from the intake pipe 102 into the discharge pipe 103 via the compressor 100. At this time, because the control unit 7 opens the control valve 121 of the compression unit 1 and closes the control valves 121 of the recompression units 2, 3, 4, 5, 6, and because the discharge pipe 103 has an open first end that is coupled with the compressor 100, and a closed second end (not shown), the fluid flows from the compressor 100 into the branch pipe 104 of the compression unit 1, and subsequently into the chamber 131.
The chamber 131 is equipped with a pressure sensor 141 and a safety valve 151, which is disposed in the chamber 131 in a known manner in order to prevent explosion taking place in the chamber 131. When the fluid pressure in the chamber 131 reaches a preset first discharge pressure, the control unit 7 closes the control valves 111, 121 of the compression unit 1.
The first recompression unit 2 includes a return flow pipe unit 20, which interconnects the outlet portion 132 of the chamber 131 and the intake pipe 102 and which has a main pipe portion 200, and a pair of first and second pipe portions 201, 202. The main pipe portion 200 has an upstream end that is connected fluidly to the outlet portion 132 of the chamber 131, and a downstream end that is connected fluidly to the upstream ends of the first and second pipe portions 201, 202. An auxiliary pipe 105 extends from and is in fluid communication with the intake pipe 102 at an intersection 106, and constitutes a portion of the return flow pipe unit 200. The first and second pipe portions 201, 202 have downstream ends that are connected fixedly to and that are in fluid communication with the auxiliary pipe 105. Each of the first and second pipe portions 201, 202 is equipped with a normal-closed control valve 211, 232, and a one- way valve 212, 233 for limiting fluid flow from the first and second pipe portions 201, 202 into the auxiliary pipe 105. Because the auxiliary pipe 105 has a first end that is connected to the intake pipe 102, and a closed second end (not shown) , the fluid can flow from the auxiliary pipe 105 into the intake pipe 102. It is noted that if a large amount of the fluid flows directly and instantly from the main pipe portion 200 into the auxiliary pipe 105, the latter may explode. The first and second pipe portions 201, 201 and the common pressure-sensing unit 8 are therefore provided in order to prevent explosion of the auxiliary pipe 105. When the fluid pressure in the chamber 131 reaches the first discharge pressure so that the fluid flows from the chamber 131 into the main pipe portion 200, the control valve 211 of the first pipe portion 201 is opened, while the control valve 232 of the second pipe portion 202 is closed, under the control of the control unit 7. The common pressure-sensing unit 8 is connected operatively to the first and second pipe portions 201, 202. When the fluid pressure in the first pipe portion 201 reaches a preset pressure value, the control unit 7 opens the control valve 232 of the second pipe portion 202 and the control valve 121 of the branch pipe 104 of the recompression unit 2. As such, the flow rate of the fluid from the auxiliary pipe 105 to the intake pipe 102 is increased. Then, because the control valve 121 of the recompression unit 2 is opened, and because the control valves 121 of the compression unit 1 and the recompression units 3, 4, 5, 6 are closed, the fluid flows from the discharge pipe 103 into the chamber 231.
The chamber 231 of the first recompression unit 2 is also equipped with a pressure sensor 241 and a safety valve 251, which have the same functions as the pressure sensor 141 and the safety valve 151 of the compression unit 1, except that the pressure sensor 241 is set at a second discharge pressure that is higher than the first discharge pressure of the pressure sensor 141 of the compression unit 1.
The remaining recompression units 3, 4, 5, 6 are similar to the first recompression unit 2 in construction.
The relationship among the chambers 131, 231, 331, 431, 531, 631 in terms of the magnitude of the discharge pressures is: 631 > 531 > 431 > 331 > 231 > 131.
The preset pressure values that are set at the common pressure-sensing unit 8 and that correspond respectively to the recompression units 2, 3, 4, 5, 6 are different from each other.
In this embodiment, the common pressure-sensing unit 8 is connected to all of the recompression units 2, 3, 4, 5, 6. Alternatively, five separate pressure-sensing units can substitute for the common pressure-sensing unit 8 to cooperate with the recompression units 2, 3, 4, 5, 6, respectively.
When the fluid flows from the compressor 100, because only one of the control valves 121 of the branch pipes 104 is open under the control of the control unit 7, the fluid can flow along a flow path of the compressor 100, the first chamber 131, the compressor 100, the second chamber 231, the compressor 100, the third chamber 331, the compressor 100, the fourth chamber 431, the compressor 100, the fifth chamber 531, the compressor 100 and the sixth chamber 631, thereby forming six compression stages to compress the fluid progressively. As such, the fluid flows through the chambers 131, 231, 331, 431, 531, 631 in a sequence that increases in the magnitude of the discharge pressures.
Accordingly, compressed fluid can be discharged from the chambers 131, 231, 331, 431, 531, 631 at different pressures.
If it is found by the control unit 7 that the fluid pressure in one of the chambers 131, 231, 331, 431, 531 drops from the corresponding discharge pressure, the control unit 7 will close all of the control valves of the recompression unit 2, 3, 4, 5, 6 succeeding to the one of the chambers 131, 231, 331, 431, 531, and open all of the control valves of the compression unit 1 or the recompression unit 2, 3, 4, 5 that precedes the one of the chambers 131, 231, 331, 431, 531 for supplement of the fluid to the one of the chambers 131, 231, 331, 431, 531. For example, when the fluid pressure in the chamber 131 drops from the first discharge pressure, the pressure sensor 141 activates the control unit 7 to close the control valves 211, 232, 121 of the first recompression unit 2 and to open the control valves 111, 121 of the compression unit 1, thereby permitting supplement of the fluid into the chamber 131 until the fluid pressure in the first chamber 131 reaches the first discharge pressure once again.
Because each adjacent pair of the chambers 131, 231, 331, 431, 531, 631 are interconnected by one of the connecting pipes 9, when the fluid pressure in the chamber 131 reaches the first discharge pressure, the fluid flows from the chamber 131 into the chambers 231, 331, 431, 531, 631 so that the fluid pressures in the chambers 231, 331, 431, 531, 631 are equal to the first discharge pressure.
Similarly, when the fluid pressure in the chamber 231 reaches the second discharge pressure, the fluid flows from the chamber 231 into the chambers 331, 431, 531, 631 so that the fluid pressures in the chambers 331, 431, 531, 631 are equal to the second discharge pressure.

Claims

A compressor apparatus including

a compressor (100);

an intake pipe (102) for delivering a fluid into the compressor (100); and

a discharge pipe (103) in fluid communication with the compressor (100) so as to permit the flow of the fluid from the compressor (100) into the discharge pipe (103);

characterized by:

means for limiting fluid flow from the intake pipe (102) into the compressor (100);

a plurality of branch pipes (104) extending from and being in fluid communication with the discharge pipe (103);

a plurality of chambers (131, 231, 331, 431, 531, 631) connected to and in fluid communication with the branch pipes (104), respectively;

means for limiting fluid flow from the branch pipes (104) into the chambers (131, 231, 331, 431, 531, 631);

a plurality of return flow pipe units (20) connected to and in fluid communication with the chambers (131, 231, 331, 431, 531, 631), respectively, and with the intake pipe (102), each of the branch pipes (104) and the return flow pipe units (20) being equipped with a control valve unit (121, 211, 232) for controlling fluid flow therethrough;

means for limiting fluid flow from the chambers (131, 231, 331, 431, 531, 631) into the intake pipe (102) via the return flow pipe units (200) ;

a plurality of pressure sensors (141, 241) disposed respectively at the chambers (131, 231, 331, 431, 531, 631) and connected operatively to the control unit (7), the sensors (141, 241) being set respectively at different discharge pressures, each of the sensors (141, 241) opening the control valve unit (121, 211, 232) of a respective one of the return flow pipe units (20) when the fluid pressure in a respective one of the chambers (131, 231, 331, 431, 531, 631) reaches a respective one of the discharge pressures, thereby permitting fluid flow from the respective one of the chambers (131, 231, 331, 431, 531, 631) to the respective one of the return flow pipe units (20) ; and

a control unit (7) connected operatively to the control valve units (121, 211, 232) so that a fluid can flow through the chambers (131, 231, 331, 431, 531, 631) in a sequence that increases in the magnitude of the discharge pressures, the fluid flowing between any consecutive pair of the chambers (131, 231, 331, 431, 531, 631) via the compressor (100) so as to form a plurality of compression stages, thereby increasing progressively the pressure of the fluid.
The compressor apparatus as claimed in Claim 1, further characterized by a cooler (101) disposed on the discharge pipe (103) so as to cool the fluid that flows therebetween.
The compressor apparatus as claimed in Claim 1, characterized in that the sensors (141, 241) are connected operatively to the control unit (7) so that when the fluid pressure in one of the chambers (131, 231, 331, 431, 531, 631) reaches the respective one of the discharge pressures, the control unit (7) opens the control valve unit (211, 232) of one of the return flow pipe units (20) that is connected to the one of the chambers (131, 231, 331, 431, 531, 631), and closes the control valve unit (121) of one of the branch pipes (104) that is connected to the one of the chambers (131, 231, 331, 431, 531, 631).
The compressor apparatus as claimed in Claim 3, characterized in that the sensors (141, 241, 341, 441, 541, 641) are connected operatively to the control unit (7) so that when the fluid pressure in the one of the chambers (131, 231, 331, 431, 531, 631) drops from the respective one of the discharge pressures, the control unit (7) closes the control valve unit (211, 232) of the one of the return flow pipe units (20), and opens the control valve unit (121) of the one of the branch pipes (104).
The compressor apparatus as claimed in Claim 1, characterized in that each of the return flow pipe units (20) includes:

an auxiliary pipe (105) having a first end that is connected fixedly to and that is in fluid communication with the intake pipe (102), and a closed second end;

a main pipe portion (200) having an upstream end that is connected to and that is in fluid communication with a respective one of the chambers (131, 231, 331, 431, 531, 631), and a downstream end;

a pair of first and second pipe portions (201, 202) having upstream ends that are connected fixedly to and that are in fluid communication with the downstream end of the main pipe portion (200), and downstream ends that are connected fixedly to and that are in fluid communication with the auxiliary pipe (105) ;

two control valves (211, 232) disposed on the first and second pipe portions (201, 202), respectively, and constituting cooperatively one of the control valve units, the control valve (211) on the first pipe portion (201) being opened by the control unit (7) when the fluid flows into the main pipe portion (200) ; and

a common pressure-sensing unit (8) connected operatively to the control valves (211, 232) so that the control valve (232) on the second pipe portion (202) opens only when the fluid pressure in the first pipe portion (201) reaches a preset pressure value, thereby preventing the explosion of the auxiliary pipe, the preset pressure values corresponding to the first pipe portions (201) of the return flow pipe units (200) being different from each other.