Development of Pulsating Jet Pump for Industrial Use

INTRODUCTION

Jet pumps are classified simple and passive machineries when compared to their mechanical counterparts like centrifugal pumps simply due to its inherent characteristics of utilizing high pressure fluid streams to entrain and boost static pressure of a second fluid to an intermediate level. It can be adopted in various application in the oil and gas sector including to maintain vacuum condition in a closed system, artificial lifts, draw water from a well through suction pipe and in atmospheric vessel sand remover.  Other applications that are amid testing include flare gas recovery, restarting of dead wells as well as boosting productions by means of reducing manifold pressure of wells [1].

A typical jet pump generally comprises of multiple sections namely a motive nozzle, a suction chamber, mixing throat along with a diffuser. Fundamentally, it operates on the infamous Bernoulli’s principle iterating the inverse relationship between the static pressure and speed of a fluid at a specified point. The conversion of internal energy into kinetic energy of motive fluid through the converging-diverging motive nozzle which allows for a high-speed exit jet stream. This induces a region of low pressure where the entrainment of secondary fluid occurs [2]. The mixing interaction between the jet motive and secondary fluid where the transfer of momentum takes place which results in the acceleration of the lower pressure fluid. Subsequently, the diffuser in place functions to recover remaining and kinetic energy which is to be converted into potential energy hence increasing the static pressure of entrainment to an intermediate level.

At present, a myriad of different jet pump configurations emerges either it being used for single phase or multiphase employment (liquid-liquid, gas-gas, liquid-gas, gas-liquid) in addition to the variations in terms of geometry, an example of this is as disclosed previously in terms of nozzle design. The working principle remains the same where a stream of relatively lower energy is induced by energy and momentum transfer sourced from a motive of higher energy [3]. The innovation of alternative jet pump designs was mainly targeted to maximize performance to be rendered competitive and increase exploration beyond niche applications. Among the geometrical parameters investigated include diameter and length of throat section, position of nozzle, primary fluid velocity and induced fluid entrance[4].

DESCRIPTION

Synergy Seal-less Pulsation Generator (Syn Pulse) is a a newly developed device specifically designed for practical industrial use to enhance performance of existing jet pumps. It is intended to provide additional suction capacity for industrial ejectors that are already being installed in the plant. Performance of ejectors degrade over time due to changing production profiles over the course of well life. Syn Pulse is able to boost the performance of available jet pumps and provides higher ejector’s suction power that are installed on such wells. It is a stand alone, seal-less (leakage free), low powered, robust device that can be fitted upstream motive pipe of conventional jet pump in operation. It is based on continuous rotation of paddles that open and close the motive pipe of standard jet pump. By doing so, normal motive flow can be converted into pulsating flow alongside the ability to supply additional energy into the working motive fluid for significantly higher suction whenever required. In other words, standard jet pump can be converted into pulsating jet pump by installing Syn Pulse at its motive. In addition to that, Syn Pulse can also be turned off, even after installation, and act as normal jet pump if needed (during optimum operating condition). Syn Pulse is mounted at motive inlet in order to convert normal motive flow, that are extensively available in industries, into pulsating flow without major interruption on inlet and discharge pressure. In short, the device only generates flow pulsation at nozzle outlet without disrupting process conditions. It acts like continuous motorized rotating valve and has minimum power required to operate since the paddle orientation is in line with motive fluid flow direction.

Our experiment has shown that by using Syn Pulse, available jet pump in operation can draw more suction fluid without altering its geometries. By pulsing motive fluid, mixing process inside mixing chamber is improved significantly, thus more suction fluid can be entrained using the same amount of motive fluid. Besides, by incorporating paddle orientation suggested in the present study provides the ability to supply additional energy into the working fluid, which results in higher nozzle velocity generated while retaining approximately similar motive mass flow rate and pressure. Syn Pulse is able to increase suction capability by more than 20% at 100 Hz. Various advantages can be acquired by using Syn Pulse including, increases performance of existing jet pumps, boosts suction rate of conventional jet pump and also allows compact jet pump design to minimize space usage especially in offshore facilities.

ADVANTAGES

  • Non-moving parts
  • Long run life due to minimum wear
  • Low maintenance cost

References

[1] G. W. Clanton, A. L. Member, and L. A. Charles, “Design and Application of the Gas Jet Ejector On Marginal Gas Wells,” J. Pet. Technol., vol. 18, no. 04, pp. 419–423, Apr. 1966, doi: 10.2118/1274-PA.

[2] M. R. Rahmathullah, K. Palani, T. Aridass, P. Ventakrishnan, and S. Palani, “A Review On Historical And Present Developments In Ejector Systems,” Int. J. Eng. Res. Appl., vol. 3, no. 2, pp. 10–34, Mar. 2013, Accessed: Nov. 30, 2021. [Online]. Available: https://www.researchgate.net/publication/258652974_A_Review_On_Historical_And_Pre
sent_Developments_In_Ejector_Systems.

[3] Z. Aidoun, K. Ameur, M. Falsafioon, and M. Badache, “Current advances in ejector modeling, experimentation and applications for refrigeration and heat pumps. Part 1: Singlephase ejectors,” Inventions, vol. 4, no. 1, Mar. 2019, doi: 10.3390/INVENTIONS4010015.

[4] S. Watanawanavet, “Optimization Of a High-Efficiency Jet Ejector By Computational Fluid Dynamic Software,” 2005.