How a Pure Steam Generator Works

The Importance of Pure Steam

A sterile and clean environment is required for many commercial applications and industries, including healthcare, pharmaceuticals, animal health, biotechnology, and cosmetics. When manufacturing the specialized equipment for these industries, clean steam generation systems must be in place to ensure sterilization for equipment such as autoclaves, washer-disinfectors, and pharmaceutical manufacturing equipment. Some breweries that want a completely pure final product also use clean steam generators to sterilize their kegs.

Having the proper sterilization equipment for these commercial applications makes all the difference in achieving the highest possible quality standards. Properly designed clean steam generators produce large amounts of pyrogen-free and endotoxin-free steam to keep production processes sterile and running smoothly. Clean steam is different from the steam generated in cooking or clothing care. True clean steam, when condensed, is suitable for water-for-injection in pharmaceuticals.

How a Pure Steam Generator Works

A pure steam generator converts incoming purified water into clean steam using utility steam on the other side of the generator as the heating medium. The utility steam and the clean steam never mix. The resulting clean steam relies on the quality of water being fed into the system. However, contaminants that do happen to get into the system can be removed by various methods.

The feedwater is pumped into the industrial clean steam generator system at a higher pressure than the required clean steam pressure to provide the temperature differential for heat transfer. Any surfaces that come into contact with the water must be made of stainless steel to maintain steam quality.

The water source for clean steam generation must be virtually free of impurities. Clean steam generation must meet very strict requirements for critical applications in industries that rely on sterile environments and equipment. It’s easy to assume that steam from boiled water is clean and pure, but the standards for “clean” water for certain uses —especially pharmaceutical applications— are exceptionally high.  

To maintain the purity of the steam generated, small traces of contamination must be captured. For that purpose, water treatment systems use fine, semi-permeable membranes to physically remove contaminants. 

This pretreatment removes contaminants in the feedwater and helps ensure clean steam is absolutely pure. Conventional water vapor is sometimes called "dirty steam" because it contains high carbon dioxide levels and other contaminants like sulfur dioxide. Water quality can also be ensured by controlling the amount of carbon dioxide, carbon monoxide, and activated carbon in the water, as well as other factors. 

High quality, clean steam generators are designed to produce a centrifugal force in the separator for less maintenance. This force propels entrained droplets to the separator's wall, effectively separating impurities. No internal components such as vanes, demisters, or baffles are needed to provide the necessary 3-log separation ratio.

Pure Steam Generator Design 
& Requirements

Because clean steam must be devoid of impurities and various chemical substances, clean steam generators are designed with specific features and elements to generate the cleanest steam. To achieve these high standards of sanitization, clean steam generators for the pharmaceutical industry must be:

• Built using corrosion-free materials such as high-quality stainless steel
• Crafted using high-quality welding, free of cracks and grooves
• Fully sealed and leak-free
• Designed to minimize stagnant water and the growth of microorganisms
• Built in compliance with the Current Good Manufacturing Practices (CGMP) defined by regulatory bodies like FDA, ASME, and JIS