The key difference between vacuum pump and compressor is that a vacuum pump does not need a storage cylinder to operate, whereas a compressor needs a storage cylinder to store the gas or air that compresses.
Vacuum pumps and compressors are important in increasing the pressure on a fluid, and both these can transport the fluid through a pipe. However, they have different requirements and mechanisms for this purpose.
CONTENTS
1. Overview and Key Difference
2. What is a Vacuum Pump
3. What is a Compressor
4. Vacuum Pump vs Compressor in Tabular Form
5. Summary – Vacuum Pump vs Compressor
What is a Vacuum Pump?
A vacuum pump is a device that can drive gas molecules from a sealed volume to leave behind a partial vacuum. A vacuum pump is important to generate a relative vacuum within a given space. The invention of the first vacuum pump was done in 1650 by Otto von Guericke. They were preceded by suction pumps.
There are three major categories of vacuum pumps: positive displacement pumps, momentum transfer pumps, and entrapment pumps. Among them, the positive displacement pumps use a method in which a cavity is repeatedly expanded to allow gases to flow in (from the chamber), seal off the cavity, and exhaust the cavity into the atmosphere. On the other hand, momentum transfer pumps (known as molecular pumps) use high-speed jets for dense fluid or high-speed rotating blades to knock off gas molecules out of the chamber. In addition, entrapment pumps tend to capture gases in a solid or adsorbed state.
Among these types, positive displacement pumps are the most effective type for a low vacuum. Momentum pumps are ideal for achieving high vacuums. Entrapment pumps use cold temperatures to condense gases to a solid or adsorbed state. There are some other types as well. Some examples include Venturi vacuum pump and steam ejector.
Usually, a vacuum pump is combined with chambers and operational procedures for a wide variety of vacuum systems. In some cases, we use more than one pump in a series or parallel arrangement for a single application. A partial vacuum can be created using a positive displacement pump that can transport a gas load from an inlet port to an outlet port.
What is a Compressor?
A compressor is a device that can increase the pressure of a gas via the reduction of volume. For example, an air compressor is a type of gas compressor. A compressor is similar to a pump. Both these devices tend to increase the pressure on a fluid, and both these can transport the fluid through a pipe. Typically, gases are compressible. A compressor tends to reduce the volume of gas. Besides, liquids are relatively incompressible. But some liquids are compressible. The main object of using a pump is to pressurize and transport liquids.
There can be different stages for the mechanism of a compressor. This means the fluid is compressed in multiple steps. This is done to increase the discharge pressure. Typically, the second stage is smaller than the primary stage by physical means. Then it can accommodate the already compressed gas without reducing the pressure of the fluid. At each stage, the gas is compressed, increasing the pressure and the temperature.
There are different types of compressors, such as reciprocating compressors, ionic liquid piston compressors, rotary screw compressors, rotary vane compressors, rolling pistons, scroll compressors, and diaphragm compressors.
What is the Difference Between Vacuum Pump and Compressor?
Vacuum pumps and compressors are important devices for compressing fluids. The key difference between vacuum pump and compressor is that a vacuum pump does not need a storage cylinder to operate, whereas a compressor needs a storage cylinder to store the gas or air that compresses.
The following table summarizes the difference between vacuum pump and compressor.
Summary – Vacuum Pump vs Compressor
A vacuum pump is a device that can drive gas molecules from a sealed volume to leave behind a partial vacuum. A compressor is a device that can increase the pressure of a gas via the reduction of volume. The key difference between vacuum pump and compressor is that a vacuum pump does not need a storage cylinder to operate, whereas a compressor needs a storage cylinder to store the gas or air that compresses.
Reference:
1. “Understanding Compressors.” Types, Applications and Selection Criteria.
Image Courtesy:
1. “Cut through turbomolecular pump” By User:Liquidat – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “High pressure compressor BellisMorcom” By Biso – Own work (CC BY-SA 4.0) via Commons Wikimedia