Thermal Oils Article
Typical Viscosity: 100cst to 2 cst
Thermal oils are used as a heat transfer medium as a way of indirectly transferring heat within a closed system, without the creation of hot spots occurring which can create damaged product through thermal cracking, thermal decomposition or solidification.
Thermal oils also provide uniform heating at a high temperature where it is not possible to have direct heat when flammable liquids such as heavy fuel oils are being handled. Tank farms have tanks heated by hot liquids to reduce the viscosity and enable easier handling.
Such fluids also provide high temperature (up to 400°C) heating without pressure which is desirable due to equipment cost and safety concerns. If water was used as a heating medium it would require high pressures to prevent the water evaporating as steam, at 233°C a pressure of 30 bar would be required to keep the water liquid rather than evaporate as steam. Piping and equipment would need to be rated at 40 bar, with periodic checks for safety.
With thermal oils much lower pressures - as little as 1-2 bar can be utilised without the risk of leaks. Furthermore the viscosity of thermal oil is much higher than steam meaning it is less likely to find a leak path. Heated water systems also require treatments to ensure calcification does not occur and also higher grades of materials.
Examples of liquids used for high temperature transfer include water glycol, propylene glycol within food, mineral oils and synthetic liquids. Example names of such liquids include dowtherm, mobiltherm and duratherm.
Some examples of typical applications include:
· As a heating jacket medium to maintain viscosity of resins,hydrocarbons, bitumen, or heavy fuel oil at petroleum terminals
· Provide consistent laboratory controlled temperatures in the pharmaceutical industry when handling high value delicate liquids
· Drying of wood in kilns
· Industrial heating
· Cooking oil manufacture & maintaining of cooking oil temperatures as burners can cause thermal decomposition
· Hot Melt glues
· Hydraulic presses in rubber, plastic and composite processing
· Heating of calendars, stamping equipment and rollers
· Heating chemical reactors
· Industrial washing machines and dryers in hospitals, laundries, retirement homes and hotels
· Superheated steam in solar thermal plants
· Flexography and rotogravure printing
We offer pumps with the following features to assist in your thermal oil pump application:
· Variable speed drive to match required demand
· Double mechanical seal and cooling fins means external cooling is not required