There are certain industries located in colder climates such as Edmonton, Alberta or even Pittsburgh, Pennsylvania that require protection to prevent their liquid products from freezing. The most susceptible are probably the oil and gas industry. It is not necessarily just the severe cold weather that prompts the worry for freezing. The petroleum and chemical products have different freezing points, and regardless of environmental conditions, it is a concern to keep these liquids and gases from freezing. The industrial heaters are used to provide freeze control to these industries. In addition to oil and gas industries, other industries such as agriculture and mining can also benefit from freeze control.The basic freeze control begins with insulation of tanks containing the liquid medium. Given the tank size, if the tank is not well insulated, it may create two temperature zones unless multiple process heaters are used. The normal freeze control is to prevent the temperature from falling below 273.15K (0C or 32F), at which point they start crystalizing. Even if some fuel oils such as Diesel do not freeze, they turn into gel or thinker wax. The best way to protect the chemicals from freezing is by using multiple industrial heater elements.
When using heaters for freeze control, the difficult part is to calculate how much power is needed to keep a certain size of tanks filled with particular contents. WATTCO™ has heating formulas to determine the power requirement versus the size of the tank in terms of gallons. The formulas are designed for both water and oil based on different Delta Temperatures. Delta Temperature (also called Delta T) is a change in temperature over a given period of time. It is calculated by taking the final temperature and then subtracting the initial temperature from it.However, there is also the location factor. Certain locations such as Denver, Colorado, would have the average temperature for winter month below 32F in which case the output of heater element must match or exceed the heat loss. Other areas that have a higher average temperature for winter months may only experience temperature drop for few hours or so. In those cases, it may be necessary to require the power just enough to maintain a working temperature for up to 72 hours.
The power requirements may also vary depending on the chemicals. For example, the motor oil such as 15W30 has a freeze point of -55F, which is well below the normal freeze point for most other chemicals. In such case, a severe cold environment may exert less effect than most other normal cases on the issue of keeping the oil from freezing.
No matter how well industrial tank heaters perform, the key to freeze control depends on how well the heat can be insulated. If the tank is not properly insulated, the heat generated will continue to be lost. This is such an important step because the other side of the tank, opposite to where the heater is located, will begin frozen very fast if the heater cannot keep up with the temperature drop in the cold weather. A tank that is well insulated will experience only about 5% of heat loss when the temperature drops below 32F, according to WATTCO™ studies. The 5% threshold is more than adequate to compensate the heat loss for the insulated tanks.