Perfected twin-screw pump, particularly suitable for pumping of biphase fluids in submarine

Abstract

A kind of twin-screw pump, in which four conical screws are vertically arranged in the pump, and two-phase fluids that are not related to each other are delivered at both ends through the liquid flow separator, and each of the two screw shafts has a connecting chamber and a series of terminations. A central axial bore connected to a radial channel at the tip of a single tooth of the screw. A preferred flow divider is described in detail.

Description

technical field [0001] The present invention relates to a twin-screw pump, which guarantees delivery by means of suction at both ends of the pump with the gas content always exactly the same, and guarantees the seal between the screw and the pump chamber wall of the pump body (and pumps the gas phase separately in an instant seal) to ensure effective and safe pumping of two-phase fluids even when the above pump is in a vertical position, making it particularly suitable for use in subsea applications. Background technique [0002] As we all know, the screw pump is mainly a rotary pump. In the pump, fluid (usually liquid) is obtained from the suction end to the output along the conical space formed by a pair of conical screw teeth that are firmly engaged with each other and in synchronous motion. The forced mechanical movement of the end, and between the two screw teeth and the pump cavity wall of the pump body, the film formed by the liquid itself under the action of centrifu...

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Problems solved by technology

[0007] However, in this special application, the above-mentioned pumps can only be installed horizontally, because the vertical installation of the pump will cause obvious separation of the gas-liquid mixture due to gravity, wherein the liquid in the mixture accumulates at the lower delivery end of the pump and On the other hand, the gas is collected at the upper delivery end of the pump. As a result, the upper screw pair, which is only in contact with the gas and not cooled by the liquid, will overheat, causing the screw to be killed.

[0008] In addition, the above-mentioned ordinary pump in the horizontal position can never turn in the presence of gas alone, which is often encountered when oil wells are pumped, and cannot be established by centrifugal force due to the lack of liquid phase in the mixture as mentioned before. The formed oil film seal damages the self-seal corresponding to the screw, so that the pump cannot rotate and stops the pumping work

[0009] Therefore, it is necessary to do everything possible to overcome the shortcomings of damaging the oil film seal, such as using a liquid seal generator that can accumulate the liquid used to maintain or establish a liquid phase of the liquid seal to provide the delivery fluid of the pump, but in the presence of a high degree of vacuum In the case where even the above solution does not completely solve the problem, the stated vacuum means the ratio between the amount of gas in the mixture and the amount of the mixture pumped

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