Tank Jet Mixer Design, Arrangement & Applications

Review Article

Austin Chem Eng. 2023; 10(1): 1097.

Tank Jet Mixer Design, Arrangement & Applications

Laxmi Advani*

L&T Energy Hydrocarbon, India

*Corresponding author: Laxmi Advani L&T Energy Hydrocarbon, A M Naik Tower, Gate 3, 14th Floor, Jogeshwari - Vikhroli Link Road, Mumbai 400072, India. Tel: 9920875709 Email: Laxmi.thakker@gmail.com

Received: June 12, 2023 Accepted: July 11, 2023 Published: July 18, 2023

Abstract

Side entry mixers or jet mixers are commonly used to achieve mixing in storage tanks and reactors. Impellers are other conventional devices used for mixing in industry, but they are expensive for large storage tanks and underground tanks.

Jet mixers have been a better alternative to impellers in the process industry. Compared with Mechanically agitated mixers, these mixers use jet technique to create high turbulence, high shear rates and vortex motion offer several advantages in achieving rapid mixing over a short period of time without any moving parts. Jet mixing has become an alternative to conventional impeller mixing for various applications in process industries. To ensure optimal mixing performance, it is important to understand the basis of jet mixer design & also impact of different parameters in jet mixer design & preferred installation of mixers.

This article shall cover following aspects:

- Jet mixer Applications, working principle & Advantages

This section elaborates jet mixer applications in various industrial applications primarily in unit processes where liquid blending, solids suspension, flow generation or chemical reactions are key process parameters. It elaborates the working principle of jet mixer & lists its various advantages.

- Design aspects of jet mixers

This section includes defining turn over time, pumpage requirement, pump capacity & power determination which will help in design of jet mixer & connected assembly.

- Experimental correlations for Mixing time estimation based on literature with their limitations

Mixing time is an important design parameter in jet mixing. Various correlations are available in literature utilizing different parameters like jet velocity, jet diameter, tank height etc. to find out the correlation for mixing time. These have been defined based on experimental CFD analysis which will provide better conclusions for mixing time. Thus, critical analysis of the available literature data has been made and some general conclusions have been drawn concerning the various parameters.

- Impact of parameters affecting mixing time

This section highlights the impact of various parameters such as tank dimensions, jet mixer dimensions & geometry, fluid properties & mixer location & configuration details.

- Mixer installation guidelines

This section elaborates guidelines for mixer installation requirements, preferred position of mixers & multiple jets consideration.

- Quick comparison of jet mixer vs agitators

Fluids mixing can usually be achieved using mechanical mixers and jet mixers. Each of these mixers may be selected and used to provide optimal operative condition.

Keywords: Jet mixing; Mixing time; Experimental; CFD; Parameters; Design

Introduction

Fluids mixing can usually be achieved using mechanical mixers and jet mixers. Each of these mixers may be selected and used in order to provide optimal operative condition. However the jet mixing system is more effective than other mixing methods because they are very expensive for large storage tanks and underground tanks. Jet mixers are used in industrial applications primarily in unit processes where liquid blending, solids suspension, flow generation or chemical reactions are key process parameters. Mixing of reactants, catalysts etc. in a chemical and bio-chemical reactor can be achieved using a jet mixer, which offers the advantages of having no moving parts inside the reactor.

Working Principle

A liquid flow is taken from the tank and supplied to the liquid jet mixing nozzles via a pump. Inside the motive nozzle pressure energy is converted into kinetic energy. Negative pressure is generated at the motive nozzle outlet and the ambient liquid is sucked in.

The suction flow is strongly intermixed with the motive flow in the adjoining mixing section and accelerated by impulse exchange. The drag effect of the exiting mixed flow increases the mixing effect significantly.

- Parts of Jet Mixer Assembly: Nozzle, Pipe, Elbow, Cone, Jet Nozzle (Below Figure 1)