Contamination control engineering design

Xpert Rule is widely used in industrial and scientific applications, one of them performed in cooperation with NASA and Rockwell Aerospace. It is called NASA s Contamination Control Engineering Design Guidelines Expert System and was developed by Rockwell International s Space Systems Division. It was developed for education in contamination control processes and is designed as an interactive guide to assist with quantifying contamination for sensitive surfaces. The tool enables the user to quantify molecular and particulate contamination requirements for solar arrays, thermal control surfaces, or optical sensors [24],... 

Laboratory development of the in situ microbial filter has been completed. According to LLNL, the key engineering design parameters have been measured under controlled conditions, and scaled laboratory experiments have demonstrated the success of the approach. A field demonstration of the biofilter concept was conducted at a contaminated site in Chico, California. 

The idea of using airflows to collect a substance similar to explosive vapors and/or particles is not unique. From an engineering systems design perspective, collecting an explosive from a person can be directly compared to local exhaust ventilation systems used in industry for contamination control, e.g., welding hoods, open vapor tanks,... 

This list is by no means exhaustive, nor is it meant to be. Rather, it is designed to create a mindset among design/development engineers that cleanability, just like manufacturability and ease of assembly, is a key price-performance issue that needs to be factored in at the outset. In the highly competitive microelectronics marketplace, effective contamination control, when properly integrated th product development, may turn out to be a big advantage. This concept has more recently been discussed in more detail in Ref 3. 

Use of chemicals is unrestricted, hazardous chemicals are frequently used. There is possibility of high risk of exposure and contamination during operations, controlled by stringent engineering controls and design requirements of such facilities and by carefully defining and monitoring work practices. 

Engineering factors include (a) contaminant characteristics such as physical and chemical properties - concentration, particulate shape, size distribution, chemical reactivity, corrosivity, abrasiveness, and toxicity (b) gas stream characteristics such as volume flow rate, dust loading, temperature, pressure, humidity, composition, viscosity, density, reactivity, combustibility, corrosivity, and toxicity and (c) design and performance characteristics of the control system such as pressure drop, reliability, dependability, compliance with utility and maintenance requirements, and temperature limitations, as well as size, weight, and fractional efficiency curves for particulates and mass transfer or contaminant destruction capability for gases or vapors. 

The engineered bioremediation system (EBS) is a proprietary process for the ex situ bioremediation of organic contaminated soils. The system is designed to enhance the natural bioremediation rate of organic constituents by controlling factors affecting microbial growth and metabolism. 

---