Basic knowledge of vacuum pump

A vacuum pump is a device that draws gas molecules from a sealed volume and maintains a partial vacuum. Its main job is to create a relative vacuum within a given volume or volumes. There are many types of vacuum pumps. This article will describe how they work, their types, and their applications.

How it works

A vacuum pump is a mechanical device that removes gas from a system by applying it to a higher pressure than the surrounding atmosphere. The working principle of the vacuum pump is based on the principle of gas transfer and entrapment. Vacuum pumps can be classified according to their vacuum level and the number of molecules that can be removed per cubic centimeter of space. In medium to high vacuum, viscous flow occurs when gas molecules collide with each other. Increasing the vacuum causes molecular or transitional flow.
A vacuum pump has several components that make it a versatile tool. One of the main components is the motor, which consists of a rotor and a stator. The rotor and stator contain coils that generate a magnetic field when excited. Both parts must be mounted on a base that supports the weight of the pump. There is also an oil drain that circulates oil throughout the system for lubrication and cooling purposes.
Another type of vacuum pump is the liquid ring vacuum pump. It works by positioning the impeller above or below the blades. Liquid ring pumps can also adjust the speed of the impeller. However, if you plan to use this type of pump, it is advisable to consult a specialist.
Vacuum pumps work by moving gas molecules to areas of higher or lower pressure. As the pressure decreases, the removal of the molecules becomes more difficult. Industrial vacuum systems require pumps capable of operating in the 1 to 10-6 Torr range.

Type

There are different types of vacuum pumps. They are used in many different applications, such as laboratories. The main purpose of these pumps is to remove air or gas molecules from the vacuum chamber. Different types of pumps use different techniques to achieve this. Some types of pumps use positive displacement, while others use liquid ring, molecular transfer, and entrapment techniques.
Some of these pumps are used in industrial processes, including making vacuum tubes, CRTs, electric lights, and semiconductor processing. They are also used in motor vehicles to power hydraulic components and aircraft. The gyroscope is usually controlled by these pumps. In some cases, they are also used in medical settings.
How a vacuum pump works depends on the type of gas being pumped. There are three main types: positive displacement, negative displacement, and momentum transfer. Depending on the type of lubrication, these principles can be further divided into different types of pumps. For example, dry vacuum pumps are less sensitive to gases and vapors.
Another type of vacuum pump is called a rotary vane pump. This type of pump has two main components, the rotor and the vacuum chamber. These pumps work by rotating moving parts against the pump casing. The mating surfaces of rotary pumps are designed with very small clearances to prevent fluid leakage to the low pressure side. They are suitable for vacuum applications requiring low pulsation and high continuous flow. However, they are not suitable for use with grinding media.
There are many types of vacuum pumps and it is important to choose the right one for your application. The type of pump depends on the needs and purpose of the system. The larger ones can work continuously, and the smaller ones are more suitable for intermittent use.

Apply

Vacuum pumps are used in a variety of industrial and scientific processes. For example, they are used in the production of vacuum tubes, CRTs, and electric lamps. They are also used in semiconductor processing. Vacuum pumps are also used as mechanical supports for other equipment. For example, there may be multiple vacuum pumps on the engine of a motor vehicle that powers the hydraulic components of an aircraft. In addition, they are often used in fusion research.
The most common type of vacuum pump used in the laboratory is the rotary vane pump. It works by directing airflow through a series of rotating blades in a circular housing. As the blades pass through the casing, they remove gas from the cavity and create a vacuum. Rotary pumps are usually single or double-stage and can handle pressures between 10 and 6 bar. It also has a high pumping speed.
Vacuum pumps are also used to fabricate solar cells on wafers. This involves a range of processes including doping, diffusion, dry etching, plasma-enhanced chemical vapor deposition, and bulk powder generation. These applications depend on the type of vacuum pump used in the process, and the vacuum pump chosen should be designed for the environment.
While there are several types of vacuum pumps available, their basic working principles remain the same. Each has different functions and capacities, depending on the type of vacuum. Generally divided into positive displacement pump, rotary vane pump, liquid ring pump, and molecular delivery pump.

Maintenance

The party responsible for general maintenance and repairs is the Principal Investigator (PI). Agknxs must be followed and approved by the PI and other relevant laboratory personnel. The Agknx provides guidelines for routine maintenance of vacuum pump equipment. Agknxs are not intended to replace detailed routine inspections of vacuum pump equipment, which should be performed by certified/qualified service personnel. If the device fails, the user should contact PI or RP for assistance.
First, check the vacuum pump for any loose parts. Make sure the inlet and outlet pressure gauges are open. When the proper pressure is shown, open the gate valve. Also, check the vacuum pump head and flow. Flow and head should be within the range indicated on the label. Bearing temperature should be within 35°F and maximum temperature should not exceed 80°F. The vacuum pump bushing should be replaced when it is severely worn.
If the vacuum pump has experienced several abnormal operating conditions, a performance test should be performed. Results should be compared to reference values ​​to identify abnormalities. To avoid premature pump failure, a systematic approach to predictive maintenance is essential. This is a relatively new area in the semiconductor industry, but leading semiconductor companies and major vacuum pump suppliers have yet to develop a consistent approach.
A simplified pump-down test method is proposed to evaluate the performance of vacuum pumps. The method includes simulated aeration field tests and four pump performance indicators. Performance metrics are evaluated under gas-loaded, idle, and gas-load-dependent test conditions.

Cost

The total cost of a vacuum pump consists of two main components: the initial investment and ongoing maintenance costs. The latter is the most expensive component, as it consumes about four to five times the initial investment. Therefore, choosing a more energy-efficient model is a good way to reduce the total system cost and payback period.
The initial cost of a vacuum pump is about $786. Oil-lubricated rotary vane pumps are the cheapest, while oil-free rotary vane pumps are slightly more expensive. Non-contact pumps also cost slightly more. The cost of a vacuum pump is not high, but it is a factor that needs careful consideration.
When choosing a vacuum pump, it is important to consider the type of gas being pumped. Some pumps are only suitable for pumping air, while others are designed to pump helium. Oil-free air has a different pumping rate profile than air. Therefore, you need to consider the characteristics of the medium to ensure that the pump meets your requirements. The cost of a vacuum pump can be much higher than the purchase price, as the daily running and maintenance costs can be much higher.
Lubricated vacuum pumps tend to be more durable and less expensive, but they may require more maintenance. Maintenance costs will depend on the type of gas that needs to be pumped. Lighter gases need to be pumped slowly, while heavier gases need to be pumped faster. The maintenance level of a vacuum pump also depends on how often it needs to be lubricated.
Diaphragm vacuum pumps require regular maintenance and oil changes. The oil in the diaphragm pump should be changed every 3000 hours of use. The pump is also resistant to chemicals and corrosion. Therefore, it can be used in acidic and viscous products.

editor by CX 2023-04-18