AUXILIARY SHAFT SEAL FLUSHING SYSTEM OF A CENTRIFUGAL PUMP AND AN AXIAL FLOW PUMP

Abstract

An auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump, comprising a main running pump and a standby pump which are provided with a same shaft seal flushing system respectively, the shaft seal flushing system of the main running pump and that of the standby pump being connected in parallel to form a common shaft seal flushing system. The common shaft seal flushing system comprises: a first outlet pipe connected to an outlet of the main running pump and a first switch valve provided on the first outlet pipe for switching the flushing fluid, a second outlet pipe connected to an outlet of the standby pump and a second switch valve provided on the second outlet pipe for switching the flushing fluid, and a first fluid guide pipe connected to the outlets of the first outlet pipe and the second outlet pipe; the outlet of the first fluid guide pipe is respectively connected to a flushing fluid inlet on a sealing gland of the main running pump by a third outlet pipe and connected to a flushing fluid inlet on a sealing gland of the standby pump by a fourth outlet pipe. The present invention can keep the parameters of the fluid material in sealed cavities of the main and standby pumps the same at all times.

Claims

1. An auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump, comprising a main running pump (1) and a standby pump (2) which are provided with a same shaft seal flushing system respectively, wherein the shaft seal flushing system of the main running pump (1) and that of the standby pump (2) being communicated in parallel to form a common shaft seal flushing system.

2. The auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump according to claim 1, wherein the common shaft seal flushing system comprises: a first outlet pipe (5) connected to an outlet (23) of the main running pump (1) and a first switch valve (3) provided on the first outlet pipe (5) for switching the flushing fluid, a second outlet pipe (6) connected to an outlet (24) of the standby pump (2) and a second switch valve (4) provided on the second outlet pipe (6) for switching the flushing fluid, and a first fluid guide pipe (7) connected to the outlets of the first outlet pipe (5) and the second outlet pipe (6); an outlet of the first fluid guide pipe (7) is respectively connected to a flushing fluid inlet on a sealing gland (10) of the main running pump (1) by a third outlet pipe (8) and connected to a flushing fluid inlet on a sealing gland (11) of the standby pump (2) by a fourth outlet pipe (9).

3. The auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump according to claim 2, wherein a coarse filter (7-1) or an orifice plate (7-2) is provided on the first fluid guide pipe (7).

4. The auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump according to claim 2 or 3, wherein a coarse filter (7-1) and an orifice plate (7-2) are provided on the first fluid guide pipe (7).

5. The auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump according to claim 2 or 3, wherein a first heat exchanger (7-3) and a first temperature indicator (7-4) are further provided on the first fluid guide pipe (7).

6. The auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump according to claim 1, wherein the common shaft seal flushing system comprises: a first outlet pipe (5) connected to an outlet (23) of the main running pump (1) and a first switch valve (3) provided on the first outlet pipe (5) for switching the flushing fluid, a second outlet pipe (6) connected to an outlet (24) of the standby pump (2) and a second switch valve (4) provided on the second outlet pipe (6) for switching the flushing fluid, a hydrocyclone separator (13) connected to the outlets of the first outlet pipe (5) and the second outlet pipe (6), a second fluid guide pipe (12) connected to a clean fluid outlet of the hydrocyclone separator (13) and a third fluid guide pipe (14) connected to a sewage outlet of the hydrocyclone separator (13), wherein an outlet of the second fluid guide pipe (12) is respectively connected to a flushing fluid inlet on a sealing gland (10) of the main running pump (1) by a fifth outlet pipe (19) and connected to a flushing fluid inlet on a sealing gland (11) of the standby pump (2) by a sixth outlet pipe (20), and the third fluid guide pipe (14) is respectively connected to an inlet (21) of the main running pump (1) by a seventh outlet pipe (15) and a third switch valve (16) provided on the seventh outlet pipe (15), and connected to an inlet (22) of the standby pump (2) by an eighth outlet pipe (17) and a fourth switch valve (18) provided on the eighth outlet pipe (17).

7. The auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump according to claim 6, wherein a second heat exchanger (12-1) and a second temperature indicator (12-2) are provided on the second fluid guide pipe (12).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is an overall structure diagram of a shaft seal flushing system of a centrifugal pump and an axial flow pump according to a first embodiment of the prior art;

[0032] FIG. 2 is an overall structure diagram of a shaft seal flushing system of a centrifugal pump and an axial flow pump according to a second embodiment of the prior art;

[0033] FIG. 3 is an overall structure diagram of a shaft seal flushing system of a centrifugal pump and an axial flow pump according to a first embodiment of the present invention; and

[0034] FIG. 4 is an overall structure diagram of an auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump according to a second embodiment of the present invention.

[0035] In which 1: Main running pump; 2: Standby pump; 3: First switch valve; 4: Second switch valve; 5: First outlet pipe; 6: Second outlet pipe; 7: First fluid guide pipe; 7-1: Coarse filter; 7-2: Orifice plate; 7-3: First heat exchanger; 7-4: First temperature indicator; 8: Third outlet pipe; 9: Fourth outlet pipe; 10: Sealing gland; 11: Sealing gland; 12: Second fluid guide pipe; 12-1: Second heat exchanger; 12-2: Second temperature indicator; 13: Hydrocyclone separator; 14: Third fluid guide pipe; 15: Seventh outlet pipe; 16: Third outlet pipe; 17: Eighth outlet pipe; 18: Fourth outlet pipe; 19: Fifth outlet pipe; 20: Sixth outlet pipe; 21: Inlet; 22: Inlet; 23: Outlet; 24: Outlet; 25: Pump shaft; 26: Pump shaft.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0036] An auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump of the present invention will be further described in detail with reference to the accompanying drawings and the embodiments.

[0037] An auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump of the present invention is achieved on the basis of the prior art as shown in FIG. 1 and FIG. 2, and achieved by connecting the flushing system of the main running system and that of the standby pump in parallel. The auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump of the present invention, as shown in FIG. 3 and FIG. 4, comprises a main running pump 1 and a standby pump 2 which are provided with a same shaft seal flushing system respectively, the shaft seal flushing system of the main running pump 1 and that of the standby pump 2 are connected in parallel to form a common shaft seal flushing system. Namely, in the chapter “standard flushing solution and auxiliary metal components” of the API 682 Appendix D (Standard Appendix), a bypass pipeline is connected with an auxiliary system pipeline of a high pressure outlet 23 of the running main running pump 1, and the other end of the bypass pipeline is connected with the corresponding position of the flushing fluid inlet on a sealing gland 11 of the currently stopped standby pump 2, so that the seal flushing system achieves the purpose of flushing the seal of the running main running pump 1 while flushing the seal of the currently stopped standby pump 2 simultaneously. Henceforth, the stopped standby pump is always kept in good condition without any risk of the seal leakage when started the standby pump, thus making the great contribution to the commitment of continuous serving the seal no less than 25000 hours.

[0038] In the auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump of the present invention, when the running fluid flowing in the main running pump 1 is the flushing fluid without particles, as shown in FIG. 3, the common shaft seal flushing system comprises: a first outlet pipe 5 connected to an outlet 23 of the main running pump 1 and a first switch valve 3 provided on the first outlet pipe 5 for switching the flushing fluid, a second outlet pipe 6 connected to an outlet 24 of the standby pump 2 and a second switch valve 4 provided on the second outlet pipe 6 for switching the flushing fluid, and a first fluid guide pipe 7 connected to the outlets of the first outlet pipe 5 and the second outlet pipe 6, wherein an outlet of the first fluid guide pipe 7 is respectively connected to a flushing fluid inlet on a sealing gland 10 of the main running pump 1 by a third outlet pipe 8 and connected to a flushing fluid inlet on a sealing gland 11 of the standby pump 2 by a fourth outlet pipe 9.

[0039] When the pressure difference between the pressure at the outlets 23, 24 of the main running pump 1 and the standby pump 2 and that at the inlets 21, 22 thereof is more than 0.3 MPa, the first fluid guide pipe 7 is provided with an orifice plate 7-2 for controlling the pressure difference between them. If there are a small amount of suspended particles with large particle size in the first fluid guide pipe 7, a coarse filter 7-1 can also be provided in the first fluid guide pipe 7.

[0040] Alternatively, the coarse filter 7-1 and the orifice plate 7-2 are all provided on the first fluid guide pipe 7.

[0041] When the temperature of the flushing fluid in the first fluid guide pipe 7 is required to be controlled, a first heat exchanger 7-3 and a first temperature indicator 7-4 can also be provided on the first fluid guide pipe.

[0042] The operation process of the auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump of the present invention is as follows: when the main running pump 1 is in operation, the first switch valve 3 is opened and the second switch valve 4 is closed, the flushing fluid flows out from the outlet 23 of the main running pump 1 and then enters into the flushing fluid inlet on the sealing gland 10 of the main running pump 1 after successively passed through the first outlet pipe 5, the first switch valve 3, the first fluid guide pipe 7 and the fourth outlet pipe 9, the fluid enters into the mechanical sealed cavity and approaches to an end of the friction pair for flushing, and then enters into the main running pump 1 after passed through the mechanical sealed cavity. Meanwhile, the flushing fluid flows out from the outlet 23 of the main running pump 1 and then enters into the flushing fluid inlet on the sealing gland 11 of the standby pump 2 after successively passed through the first outlet pipe 5, the first switch valve 3, the first fluid guide pipe 7 and the third outlet pipe 9, the fluid enters into the mechanical sealed cavity and approaches to an end of the friction pair for flushing, and then enters into the standby pump 2 after passed through the mechanical sealed cavity.

[0043] In the above operation process, the main running pump 1 and the standby pump 2 can be used interchangeably, i.e., the standby pump 2 serves as a main running pump while the main running pump 1 serves as a standby pump, and the operation process is as mentioned above.

[0044] In another exemplary embodiment of the auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump of the present invention, when the flushing fluid flowing in the main running pump 1 contains suspended particles with high density, the common shaft seal flushing system as shown in FIG. 4 comprises: a first outlet pipe 5 connected to an outlet 23 of the main running pump 1 and a first switch valve 3 provided on the first outlet pipe 5 for switching the flushing fluid, a second outlet pipe 6 connected to an outlet 24 of the standby pump 2 and a second switch valve 4 provided on the second outlet pipe 6 for switching the flushing fluid, a hydrocyclone separator 13 connected to the outlets of the first outlet pipe 5 and the second outlet pipe 6, a second fluid guide pipe 12 connected to a clean fluid outlet of the hydrocyclone separator 13 and a third fluid guide pipe 14 connected to a sewage outlet of the hydrocyclone separator 13, wherein an outlet of the second fluid guide pipe 12 is respectively connected to a flushing fluid inlet on a sealing gland 10 of the main running pump 1 by a fifth outlet pipe 19 and connected to a flushing fluid inlet on a sealing gland 11 of the standby pump 2 by a sixth outlet pipe 20, and the third fluid guide pipe 14 is respectively connected to an inlet 21 of the main running pump 1 by a seventh outlet pipe 15 and a third switch valve 16 provided on the seventh outlet pipe 15, and connected to an inlet 22 of the standby pump 2 by an eighth outlet pipe 17 and a fourth switch valve 18 provided on the eighth outlet pipe 17. When the temperature of the flushing fluid in the second fluid guide pipe 12 is required to be controlled, a second heat exchanger 12-1 and a second temperature indicator 12-2 can also be provided on the second fluid guide pipe.

[0045] The operation process of the above auxiliary shaft seal flushing system of a centrifugal pump and an axial flow pump of the present invention is as follows: when the main running pump 1 is in operation, the first switch valve 3 and the third switch valve 16 are opened and the second switch valve 4 and the fourth switch valve 18 are closed, the flushing fluid flows out from the outlet 23 of the main running pump 1 and then enters into the hydrocyclone separator 13 after successively passed through the first outlet pipe 5 and the first switch valve 3 for separation, and the separated clean fluid without large particles enters into the flushing fluid inlet on the sealing gland 10 of the main running pump 1 after successively passed through the second fluid guide pipe 12 and the fifth outlet pipe 19; the fluid enters into the mechanical sealed cavity and approaches to an end of the friction pair for flushing, and then enters into the main running pump 1 after passed through the mechanical sealed cavity. Meanwhile the separated flushing fluid enters into the flushing fluid inlet on the sealing gland 11 of the standby pump 2 after successively passed through the second fluid guide pipe 12 and the sixth outlet pipe 20, the fluid enters into the mechanical sealed cavity and approaches to an end of the friction pair for flushing, and then enters into the standby pump 2 after passed through the mechanical sealed cavity. The separated sewage fluid containing a large amount of suspended particles with high density flows back to the inlet 21 of the main running pump 1 through the third fluid guide pipe 14.

[0046] In the above operation process, the main running pump 1 and the standby pump 2 can be used interchangeably, i.e., the standby pump 2 serves as a main running pump while the main running pump 1 serves as a standby pump, and the operation process is as mentioned above.