VACUUM SCIENCE BLOG

Fore vacuum pumps are defined as those which exhaust to atmospheric pressure. They are also required to support secondary pumps or to attain the initial conditions for their operation. There are two types of fore vacuum pumps:

• Dry-running backing pumps such as scroll, screw and diaphragm pumps.
• Oil-sealed pumps such as rotary vane pumps.
  

In this blog post, we’ll examine the key working principles of common multi-stage roots fore vacuum pumps.

Fore vacuum pumps are defined as those which exhaust to atmospheric pressure. They are also required to support secondary pumps or to attain the initial conditions for their operation. There are two types of fore vacuum pumps:

The storage and transport of COVID-19 vaccines has to be managed in a cold chain, with the first approved vaccine by Pfizer-BioNtech requiring storage temperatures of -70 C. Besides using dry ice (solid carbon dioxide at -75.8 C), Vacuum Insulated Panels and vacuum insulation have become attractive solutions.

High Vacuum (HV) and Ultra-High Vacuum (UHV) levels can only be effectively and efficiently obtained by using a main pump that has the functional capabilities. Choosing which pump to use depends on a number of factors, such as noise/vibration, cost (initial and on-going), tolerance to contamination, footprint, maintenance schedules, and resilience to shock.

In our previous blog post, Introduction to Vacuum Coating Technology, we shared various PVD (Physical Vapor Deposition) methods and showed typical products being coated using vacuum technologies. Thin films can be adhered to metal, glass, plastics, ceramics, or paper. In this blog post we will focus on Thermal Evaporation techniques.

This blog is based on the article in Applied Science and Convergence Technology 26 (5): 95-109 (2017) R Grinham and A Chew.

There are four main ways you can reduce outgassing in your vacuum system. These are: cleaning and handling, surface treatment, passivation, and purging and backfilling. In this blog, we will take a closer look at each of these methods. 

This blog is based on the article in Applied Science and Convergence Technology 26 (5): 95-109 (2017) R Grinham and A Chew.

There are several contributions to the gas load of a system. At pressures below ~0.1 mbar, the most dominant is often ‘outgassing’. Outgassing is the result of desorption of previously adsorbed molecules, bulk diffusion, permeation and vapourisation. Adsorption occurs via two main processes, physisorption and chemisorption, and can be described using five (or six) classifying isotherms. 

Measuring vacuum pressure is a fundamental element of all vacuum applications, but there’s no such thing as a universal vacuum gauge.

When it comes to measuring vacuum pressure, no single gauge will respond accurately throughout the entire vacuum range (from atmospheric pressure to 10^-12 mbar). That’s why a clear understanding of the differences between the types of gauges is essential to match them to the right operational contexts. 

Space technology and research would be nowhere without vacuum technology. But, with such complex work, it’s easy to lose sight of where (and how and why) vacuum plays such an important role. So we’ve published a new eBook that unpacks the most common applications of vacuum technology in space — with details on how it supports space flights, space simulation and vacuum testing and fundamental space research.

Vacuum Coating — also called ‘Thin Film Technology’; or Physical Vapour Deposition (PVD) — represents an impressive share among the various applications of vacuum technology. In this blog post, we share an overview of the historical development, the various basic principles underpinning the generating of thin films, and the general layout of coating devices.