The Caribbean Industrial Research Institute (CARIRI) is a research and technological organization that is committed to the development of innovative ideas, products and services locally and regionally. As part of CARIRI’S strategic thrust to more substantively contribute to the achievement of the national developmental goals of economic diversification and sustainability, the Institute has been turning its attention to capacity building for Innovation and Technology, recognizing that these are the primary drivers of international competitiveness and business growth. In this context, CARIRI has been taking a number of initiatives in the area of Research, Development and Innovation (RDI) aimed at strengthening and expansion of existing businesses, and fostering of new business creation.
One such initiative has involved the undertaking of in-house developmental work to formulate a water-based engine coolant for use in tropical environments, for which the Institute has received provisional patent approval in the USA. The need for such a product stemmed from the recognition that coolants currently available on the market are not specifically suited to tropical climates.
What is a Coolant? According to Wikipedia, a coolant is a fluid which flows through or around a device to prevent the device from overheating, transferring the heat produced by the device to other devices that either use or dissipate it.
CARIRI’s Metallurgy department has been working astutely on formulating this water-based engine coolant for use in tropical environments and they have received patent approval.
Internal combustion engines (Diesel and Otto cycle engines) generate a considerable amount of heat, much of which has to be dissipated from the body of the engine itself into a cooling system. In most cases the cooling system consists of a coolant liquid circulating through a heat exchanger (radiator) which is fan cooled to dissipate the heat.
The use of water as an engine coolant causes problems especially in very cold climates where freezing temperatures can cause ice to form in the cooling system where it can damage radiators, connecting pipes and the engine block itself due to expansion. Water as a cooling medium is also not ideal under warm weather conditions as it may boil off or evaporate from cooling systems. Plain water as an engine coolant has an additional disadvantage in that water causes corrosion of engine components.
To overcome these problems, a number of chemicals have been used with and without water as engine coolants. The most common coolants are now water-based mixtures utilizing polyethylene glycol as an additive. Mixing polyethylene glycol with water slightly raises water’s boiling point but considerably reduces water’s freezing point. For example, a 1:1 mixture of water and glycol freezes at about minus 37 °C and the boiling point is slightly raise (105 °C).
Most modern coolants use 30-100 percent ethylene glycol or propylene glycol with water. However these mixtures cause corrosion of engine components. To remedy the corrosive properties of ethylene glycol and or propylene glycol water-based coolants, modern coolants include various types of corrosion inhibitors.
The use of glycol-based anti-freezes in tropical climates has significant disadvantages. Glycols reduce water’s ability to dissipate heat. Thermal conductivity of glycols is about 50% lower than water. Glycols also promote scale formation on the surface of radiators which adversely affects the performance of engines. At high temperatures, glycols decompose to form organic acids which adversely affect metals resulting in leakage of radiators.
Another prominent disadvantage of Glycols is the health effects because it is a poisonous substance. Ethylene glycols are sweet in odour and taste and attract animals and children. Thousands of cases of accidental ingestion of coolants by children and concomitant fatal injuries occur each year. As a further disadvantage, Ethylene glycol and other glycols are non-biodegradable. Entry of ethylene glycol and other glycols into the environment (i.e. rivers, lakes, streams, and seas) poisons fish and other aquatic life.
CARIRI’s invention provides a water-based coolant for warm climates that overcomes many of the disadvantages listed above. The invention is a non-toxic coolant with high thermal conductivity and elevated boiling point that incorporates corrosion inhibitors to prevent corrosion of engine components. CARIRI is proud to be the first to receive a patent for a coolant which incorporates eco-friendly additives such as Aloe-Vera.
A feature of the invention is the combination of dissolved corrosion inhibitors and hygroscopic substances in anti-boil fluids. An advantage of the invention is that the combination prevents corrosion of the cooling system of an engine while simultaneously preventing evaporation i.e. loss of water from the coolant. Another advantage of the invention is that the hygroscopic substances impart a longer shelf life to the invented coolant and increase time between coolant fill ups saving you the consumer both time and money!
If you have more questions about this coolant, then please contact the Metallurgy Unit at 299-0210 ext 5687 or 310-4529 or email us at jramoutar@cariri.com
