Many alternative ecofriendly quenchants have been developed to replace mineral oil such as vegetable oils, polymer quenchants, and nanofluids. Although vegetable oils show superior cooling performance to mineral oil, their use is limited due to high production costs and low thermal stability. In this study, used coconut oil was chemically treated and its cooling and heat transfer characteristics were compared with that of refined coconut oil and mineral oil. The thermophysical properties of chemically treated waste coconut oil were found to be higher than that of the other oils tested, and its wettability proved to be better as well. Quenching experiments using an Inconel 600 probe (as per ISO 9950 and ASTM D 6200 standards) showed that the vapor blanket stage was shorter for the chemically treated oil than either of the others. The treated waste oil was also found to have the highest average peak heat flux based on the solution to the inverse heat conduction problem.

A variety of test systems have been developed to determine the cooling characteristics of quenchants. Although current test standards specify cylindrical probes for measuring quenchant temperatures and cooling rates, this review concerns the development, implementation, and potential of test systems that use ball probes instead. It assesses the strengths and limitations of different types of ball probes and describes prototype test systems that leverage ball probe capabilities while compensating for inherent weaknesses.

Refractory Ceramic Fiber (RCF) was invented in the early 1940's. The importance of that invention is really quite misunderstood and undervalued. With RCF Fiber attributes such as; lightweight and easy to cut and fit, virtually immunity to thermal shock, low heat capacity and low thermal conductivity, the invention of this fiber transformed industrial market refractory linings. It's impossible to calculate or predict the immense amount of energy saved and production costs lowered by the use of RCF. RCF has long been viewed as a leading choice in high temperature insulation in many industrial applications from ceramics to power generation, chemical and petrochemical processing and aerospace to domestic appliances. RCF manufacturers formed the HTIW Coalition and ECFIA to represent the High Temperature Insulation Wool Industry and to work alongside government bodies to recommend appropriate guidelines for using RCF. The University of Cincinnati in the US and the Institute of Occupational Medicine in the EU have and continue to study and monitor RCF in the workplace However, regulations placed upon working with RCF in Europe have encouraged ceramic fiber manufactures to develop viable alternatives to RCF. These high temperature low bio-persistent alkaline earth silicate (AES) fibers were developed in the late 1980s as an alternative to RCF fibers. Driven by the European regulations, AES fibers have been used to replace RCF in many different and wide ranging industrial and commercial applications.