RU2116518C1 - Centrifugal pump impeller - Google Patents

Abstract

FIELD: production of oil from flow rate wells. SUBSTANCE: impeller is provided with drive and driven disks and blades 3 secured between them forming inner-blade passages 4 where partitions 5 are located. Each partition 5 is secured on side surfaces of adjacent blades 3 forming blanked-off section 6 in inter-blade passage 4. Sections 6 form actually stagnant zones. Impeller is provided with at least one partition 5. Maximum number of partitions 5 is lesser than number of inter-blade passages 4 by one. Each partition 5 is located at distance equal to 0.9 of length of blade 3 from inlet of inter-blade passage 6. Partitions 5 may vary in form. Blanked-off sections 6 may be provided with additional vortex-forming blades whose number corresponds to number of blades. Formation of zones of intensive vorticity enhanced degree of dispersion of mechanical admixtures, excludes deposition of solid phase and choking of pump working members. EFFECT: high degree of dispersion of mechanical admixtures, avoidance of deposition of solid phase and choking of pump working members. 8 cl, 7 dwg

Description

 The invention relates to a pump engineering and can be used in the oil and gas industry for oil production from low-production wells containing mechanical impurities.

 The impeller of a centrifugal pump for heterogeneous media is known, containing a driving and driven disks and blades installed between them, the output parts of which have thickenings on the working side, partially overlapping the inter-blade channels (ed. St. USSR N 802635, class F 04 D 29/22 , 1981).

 However, this device provides a low degree of dispersion.

 Of the known devices, the closest to the invention is the impeller of a centrifugal pump containing a driving and driven discs with blades fixed between them with the formation of inter-blade channels in which partitions are located [1].

 However, the known wheel does not provide a sufficiently high degree of dispersion at low feeds, which excludes the possibility of using it for pumping liquid from low-rate oil wells, the products of which contain mechanical impurities.

 The basis of the invention is the creation of the design of the impeller of a centrifugal pump, providing a high degree of dispersion at low feeds, sufficient for efficient pumping of liquid with mechanical impurities from low-rate oil wells.

The problem is achieved in that in the impeller of a centrifugal pump containing a drive and a driven disc with blades fixed between them with the formation of interscapular channels, in which partitions are located, according to the invention, each partition is fixed with its ends on the side surfaces of adjacent vanes with the formation of a muffled section of the interscapular channel and the number of partitions K corresponds to the condition
1≤K≤Z-1
where Z is the number of interscapular canals.

 each partition being located at a distance from the entrance to the interscapular canal, which is not more than 0.9 of the blade length. In preferred embodiments, the partitions can be made in the form of plates of rectangular section, circular arcs, plates of cylindrical section, biconcave menisci, two plates connected at an angle to each other.

 It is advisable to install additional vortex forming blades in the output part of the muffled sections of the interscapular canals, and the number of the latter may correspond to the number of partitions.

 The proposed design of the impeller of a centrifugal pump due to the fixing of partitions on adjacent blades with the formation of a damped section - the interscapular channel, i.e., the creation of virtually stagnant zones, provides the formation of zones of intense vortex formation in stagnant zones and non-damped sections of the interscapular channels due to flow separation at the boundary of these zones and plots. This helps to increase the degree of dispersion of mechanical impurities, to prevent the deposition of solid deposits and clogging of the working parts of the pump, which will increase the efficiency of pumping liquids with mechanical impurities from low-production wells and the overhaul period of the well. At the same time, at least one interscapular channel must not be plugged to ensure a continuous supply of fluid, and at least one of the interscapular channels must have a partition to create a vortex formation zone. In addition, it was experimentally established that the maximum efficiency of vortex formation can be achieved provided that the septum is located at a distance from the entrance to the interscapular canal, which is no more than 0.9 blade lengths. The implementation of partitions in the form of plates of rectangular or cylindrical section, or in the form of arcs of circles, provides optimal conditions for pumping liquid with a small content of mechanical impurities.

 The implementation of partitions in the form of biconcave menisci or in the form of two plates connected at an angle to each other, provides optimal conditions for pumping liquid with a high content of mechanical impurities.

 Due to the installation of additional vortex-forming blades in the outlet part of the muffled sections of the interscapular channels, the efficiency of pumping a liquid with a high content of mechanical impurities can be increased.

 Additional blades allow the vortex energy to be converted to an additional pressure created by a centrifugal pump. In cases where it is required to create increased pressure values for pumping oil from low-production wells, the number of additional shortened blades corresponds to the number of partitions.

 In FIG. 1 shows a impeller of a centrifugal pump, a longitudinal section; in FIG. 2 - the same meridian section with partitions in the form of plates of rectangular section; in FIG. 3 - embodiment of the partition in the form of arcs of circles; in FIG. 4 - an embodiment of partitions in the form of plates of cylindrical section; in FIG. 5 is an embodiment of partitions to the form of biconcave menisci; in FIG. 6 is an embodiment of partitions in the form of two plates connected at an angle to each other; in FIG. 7 - an embodiment of the impeller with the installation of additional vortex-forming blades in the output part of the muffled sections of the interscapular channels.

The impeller of a centrifugal pump (see Fig. 1,2) contains a driving and driven discs 1,2 with blades 3 fixed between them with the formation of interscapular channels 4, in which partitions 5 are located. Partitions 5 are fixed with their ends on the lateral surfaces of adjacent blades 3 with the formation of muffled sections of 6 interscapular canals, and the number of partitions K corresponds to the condition
1≤K≤S-1
where Z is the number of interscapular canals.

 Moreover, each partition 5 is located at a distance from the entrance to the interscapular channel 4, which is not more than 0.9 of the blade 3. The partitions 5 can be made in the form of plates of rectangular cross section (Fig. 1, 2), circular arcs (Fig. 3) , plates of cylindrical section (Fig. 4), biconcave menisci (Fig. 5), as well as two plates mounted at an angle to each other (Fig. 6).

 In one embodiment of the impeller (Fig. 7), additional eddy-forming blades 7 are installed in the output part of the blanked sections of the interscapular channels 4. The number of additional blades 7 may correspond to the number of partitions 5.

 The impeller of a centrifugal pump operates as follows.

 Water-oil and gas mixture with mechanical impurities enters from the wellbore into the interscapular channels 4, formed by the blades 3, as well as the leading and driven disks 1, 2. During the interaction of the mixture flow with the blades 3 and partitions 5 in the interscapular channels 4, intensive vortex formation occurs, which leads to crushing of deposits solid phase and prevents impeller clogging with mechanical impurities. At high concentrations of solids and free gas in the pumped-out products, effective vortex formation is ensured by exposure to the flow of blades 3, partitions 5 and additional blades 7, which actively contribute to the creation of vortex zones in difficult operating conditions.

 After passing through the impeller, the production of the well enters a guiding apparatus (not shown), where the acquired kinetic energy of the flow is not converted into potential pressure energy.

 Thanks to the creation of zones of intense vortex formation and preventing clogging of the impeller by mechanical impurities of the proposed design, it becomes possible to successfully pump low-rate oil wells. Tests of the model impeller of the proposed design under complicated conditions have shown that clogging of the wheel by mechanical impurities does not occur.

Claims (8)

1. The impeller of a centrifugal pump containing a driving and driven disks with blades fixed between them with the formation of interscapular channels, in which there are partitions, characterized in that each partition is fixed with its ends on the side surfaces of adjacent vanes with the formation of a damped section of the interscapular channel, and, the number of partitions K corresponds to the condition
1 ≤ K ≤ Z - 1,
where Z is the number of interscapular canals,
and each septum is located at a distance from the entrance to the interscapular canal, which is not more than 0.9 of the blade length.  2. The wheel according to claim 1, characterized in that the partitions are made in the form of plates of rectangular cross section.  3. The wheel according to claim 1, characterized in that the partitions are made in the form of arcs of circles.  4. The wheel according to claim 1, characterized in that the partitions are made in the form of plates of cylindrical section.  5. The wheel according to claim 1, characterized in that the partitions are made in the form of biconcave menisci.  6. The wheel according to claim 1, characterized in that the partitions are made in the form of two plates connected at an angle to each other.  7. The wheel according to claim 1, characterized in that in the output part of the muffled sections of the interscapular channels installed additional vortex-forming blades.  8. The wheel according to claim 7, characterized in that the number of additional blades corresponds to the number of partitions.

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