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## Ejector Design Calculation PDF: A Comprehensive Guide for Engineers and Students

Ejectors are devices that use a high-pressure fluid to create a low-pressure zone and entrain another fluid. They are widely used in various industries, such as chemical, petroleum, power, refrigeration, and aerospace. Ejectors have many advantages, such as simplicity, reliability, low cost, and low maintenance.

However, designing and calculating ejectors can be challenging, especially for complex applications. There are many factors that affect the performance and efficiency of ejectors, such as geometry, operating conditions, fluid properties, and flow regimes. Therefore, it is important to have a good understanding of the theory and principles of ejector design and calculation.

• What are ejectors and how do they work?

• What are the types and classifications of ejectors?

• What are the main components and parameters of ejectors?

• What are the methods and steps of ejector design and calculation?

• What are the tools and software for ejector design and calculation?

• What are the applications and examples of ejectors?

By the end of this article, you will be able to design and calculate ejectors for any project with confidence and ease.

## What are ejectors and how do they work?

Ejectors are devices that use a high-pressure fluid (called the motive fluid) to create a low-pressure zone (called the suction chamber) and entrain another fluid (called the suction fluid). The mixture of the motive fluid and the suction fluid then passes through a diffuser (called the discharge chamber), where the pressure is recovered and the velocity is reduced.

The basic principle of ejectors is based on the conservation of mass, momentum, and energy. The motive fluid expands through a nozzle (called the motive nozzle), converting its pressure energy into kinetic energy. The high-velocity jet of the motive fluid entrains the suction fluid by creating a low-pressure zone in the suction chamber. The mixture of the two fluids then flows through a diffuser, where the kinetic energy is converted back into pressure energy.

The performance and efficiency of ejectors depend on the ratio of the mass flow rates of the motive fluid and the suction fluid (called the entrainment ratio), and the ratio of the pressures at the inlet and outlet of the ejector (called the compression ratio). The entrainment ratio indicates how much suction fluid can be entrained by a given amount of motive fluid. The compression ratio indicates how much pressure can be recovered at the outlet of the ejector.

The following figure shows a schematic diagram of an ejector and its main components and parameters:

## What are the types and classifications of ejectors?

Ejectors can be classified into different types based on various criteria, such as:

• The number of motive nozzles: single-nozzle or multi-nozzle ejectors.

• The number of suction inlets: single-inlet or multi-inlet ejectors.

• The number of stages: single-stage or multi-stage ejectors.

• The type of motive fluid: gas or liquid ejectors.

• The type of suction fluid: gas or liquid ejectors.

• The type of diffuser: constant-area or variable-area ejectors.

• The operating mode: constant-pressure or variable-pressure ejectors.

The following table summarizes some common types and examples of ejectors:

TypeDescriptionExample

Single-nozzle single-inlet single-stage gas-gas constant-area constant-pressure ejectorA simple type of ejector that uses a single nozzle to entrain a single gas stream with another gas stream. The diffuser has a constant cross-sectional area and operates at a constant outlet pressure.A steam jet air ejector that uses steam as the motive fluid to entrain air from a vacuum chamber.

Multi-nozzle single-inlet single-stage gas-gas variable-area constant-pressure ejectorA type of ejector that uses multiple nozzles to entrain a single gas stream with another gas stream. The diffuser has a variable cross-sectional area that adapts to the flow conditions and operates at a constant outlet pressure.A supersonic wind tunnel that uses multiple nozzles to entrain air from an atmospheric chamber with high-pressure air from a reservoir.

Single-nozzle multi-inlet single-stage gas-liquid constant-area variable-pressure ejectorA type of ejector that uses a single nozzle to entrain multiple liquid streams with a gas stream. The diffuser has a constant cross-sectional area and operates at a variable outlet pressure depending on the flow demand.A water jet pump that uses air as the motive fluid to entrain water from multiple sources such as wells or tanks.

Single-nozzle single-inlet multi-stage gas-gas variable-area constant-pressure ejectorA type of ejector that uses a single nozzle to entrain a single gas stream with another gas stream in multiple stages. Each stage has its own diffuser with a variable cross-sectional area that adapts to the flow conditions and operates at a constant outlet pressure.A vacuum pump that uses steam as the motive fluid to entrain air from a low-pressure chamber in several stages to achieve a high vacuum level.

Single-nozzle single-inlet single-stage liquid-liquid constant-area constant-pressure ejectorA type of ejector that uses a single nozzle to entrain a single liquid stream with another liquid stream. The diffuser has a constant cross-sectional area and operates at a constant outlet pressure.A hydraulic jet pump that uses water as

## Ejector Design Calculation PDF: A Comprehensive Guide for Engineers and Students

Ejectors are devices that use a high-pressure fluid to create a low-pressure zone and entrain another fluid. They are widely used in various industries, such as chemical, petroleum, power, refrigeration, and aerospace. Ejectors have many advantages, such as simplicity, reliability, low cost, and low maintenance.

However, designing and calculating ejectors can be challenging, especially for complex applications. There are many factors that affect the performance and efficiency of ejectors, such as geometry, operating conditions, fluid properties, and flow regimes. Therefore, it is important to have a good understanding of the theory and principles of ejector design and calculation.

• What are ejectors and how do they work?

• What are the types and classifications of ejectors?

• What are the main components and parameters of ejectors?

• What are the methods and steps of ejector design and calculation?

• What are the tools and software for ejector design and calculation?

• What are the applications and examples of ejectors?

By the end of this article, you will be able to design and calculate ejectors for any project with confidence and ease.

## What are ejectors and how do they work?

Ejectors are devices that use a high-pressure fluid (called the motive fluid) to create a low-pressure zone (called the suction chamber) and entrain another fluid (called the suction fluid). The mixture of the motive fluid and the suction fluid then passes through a diffuser (called the discharge chamber), where the pressure is recovered and the velocity is reduced.

The basic principle of ejectors is based on the conservation of mass, momentum, and energy. The motive fluid expands through a nozzle (called the motive nozzle), converting its pressure energy into kinetic energy. The high-velocity jet of the motive fluid entrains the suction fluid by creating a low-pressure zone in the suction chamber. The mixture of the two fluids then flows through a diffuser, where the kinetic energy is converted back into pressure energy.

The performance and efficiency of ejectors depend on the ratio of the mass flow rates of the motive fluid and the suction fluid (called the entrainment ratio), and the ratio of the pressures at the inlet and outlet of the ejector (called the compression ratio). The entrainment ratio indicates how much suction fluid can be entrained by a given amount of motive fluid. The compression ratio indicates how much pressure can be recovered at the outlet of the ejector.

The following figure shows a schematic diagram of an ejector and its main components and parameters:

## What are the types and classifications of ejectors?

Ejectors can be classified into different types based on various criteria, such as:

• The number of motive nozzles: single-nozzle or multi-nozzle ejectors.

• The number of suction inlets: single-inlet or multi-inlet ejectors.

• The number of stages: single-stage or multi-stage ejectors.

• The type of motive fluid: gas or liquid ejectors.

• The type of suction fluid: gas or liquid ejectors.

• The type of diffuser: constant-area or variable-area ejectors.

• The operating mode: constant-pressure or variable-pressure ejectors.

The following table summarizes