Oil Flushing for the Process Industry

WATTCO develops and manufactures a range of professional-grade immersion and circulation oil heaters for the process industry.
 
One important application of highly efficient immersion heaters for oil is in oil flushing. This application is required in the petrochemical industry to clean pipes, oil transportation lines, and hydraulic systems.

WATTCO industrial heaters are capable of heating oils that are circulated through such process systems to remove contaminants such as rust and dust. A highly cleaned system increases the efficiency of the process. In the process industry, oil flushing reduces bearing damages as it helps to dislodge any particle that is trapped inside the bearing system.  Oil flushing is an important pre-commissioning step for process heating systems. For example, oil flushing ensures that process equipment such as hydraulic systems operate smoothly and efficiently. In addition oil flushing reduces any kind of failure prematurely.
 

Figure 1: Circulation heater for the process industry. Immersion heaters are also used.
 
Viscosity and Temperature

During oil flushing, the engineer or technician must keep a close eye on the viscosity of the oil. Determining the correct viscosity is critical to performing oil flushing in the process industry.

The oil should have a low viscosity so it can flow well inside the system that is being cleaned. This is particularly important in situations where, due to ambient conditions (e.g., stormy weather), adequate heating is not possible.

However, the process engineer should be careful not to keep the viscosity at a very low value.

When oil with low viscosity is used, the flushing is not done properly inside the pipe
as the oil won't be able to carry the particles or contaminants to the filter.

The temperature of the oil is also very important as higher temperature oil helps to remove dirt that is associated with grease. A typical but useful flushing temperature should lie between 50 to 60 degree Celsius as this creates turbulent flow (desired Reynolds number: about 3,000) necessary for oil flushing.  Also this temperature range does not allow oxidation. A higher temperature (about 80 degree Celsius) is considered when the oil is to be discarded after the flushing or oil with high viscosity is used. 
 
Selection of heaters for oil flushing
 
For the process industry, immersion heaters such as screw plug and flanged immersion heaters are suitable for oil flushing. These heaters use a highly efficient direct immersion heating method where heat is directly applied to the oil. Immersion heaters are equipped with devices and circuitry for temperature control.
 
The process engineer applies his/her knowledge and acumen when selecting and installing immersion heaters.  A flanged heater is installed by bolting it to a matching flange that is welded to the tank wall or nozzle.
 
Screw plug heaters are installed in the vessel or tank (that has a threaded opening) directly.
 
The construction of the heater and its components (for example, sheath material) are important for oil flushing.  The process engineer must choose a sheath material based on the: 1) viscosity, 2) specific density 3) corrosive properties of the heated medium and 4) the corrosion resistive properties.
 
Selection of the proper heater also depends on heat or Watt requirements, flange sizes, number of elements, kilowatt ratings and terminal enclosures.
 
Looking for an oil flushing solution? Get a quote on a flanged immersion heater today. WATTCO also manufactures other industrial heating elements such as control panels, pipe heaters, inline heaters and more. View all of our industrial heating products on the Our Products page.