Immersion Heater

For any Production/process facility, when a large volume of fluid to be heated before pumping out to process application, the Immersion Heaters are always the best-recommended solutions. A single bundle or multiple smaller units can be installed in the Tank for the uniform heat transfer and steady heating of the fluid with all safety precautions in built within the heater and control system.

Some of the precautions to be taken while designing and selecting an Immersion heater are

• Selection of right material for the wet parts to avoid potential corrosion from the fluid to be heated.
• Proper cold length & active length ratio to avoid hot spots & dry heating.
• Element skin temperature within flash point limit of the fluid to avoid any hazard. A Proper thermal design is very much necessary whenever heating a flammable fluid or in hazardous area installation.
• Fixing method & support for the bundle considering the turbulence during the in & outflow.
• Control system for both element skin & fluid temperature.

Construction
Terminal Enclosure: Marathon flameproof heaters are certified to install in hazardous area Zone 1 & 2 , Gas group IIC, IP66. The Terminal enclosure is designed to protect the terminals of the individual elements from external impacts, such as dust, moisture etc and to facilitate the connection of the Incoming power supply to the heater bundle.

Heater Bundle: Consist of No. of U Pin heating elements adequately supported by set of Baffles & Tie rods, designed to deliver the specified temperature at outlet by maintaining the element temperature & pressure drop within the safe limits. Heating elements can be fixed to heater flange by means of standoff sleeve pipes with brazing or by direct welding or by means of threaded couplings. Heat duty of a bundle can be divided in to many sub groups (banks) based on process conditions. This will help in better control as flexibility in the operation.

Temperature Sensors: The Heater bundle will have Element skin temperature sensor for monitoring and regulating the Element skin temperature within the limits. The Unit may also need additional sensors such as Tube sheet Temperature Sensor, Terminal Box Sensor, vessel Body temperature sensor and process fluid Temperature sensors based on case to case. The Sensors used for the system will be certified in accordance with the area of installation. The Temperature sensors are Typically RTD or Thermocouple. A simple heater bundle can also be controlled using Thermostat protection for skin & process temperature. If the Operation pressure is High, It is recommended to have a PSV (Pressure safety Valve) installed within the Heater Vessel as an additional safety measure.

Control Panel: Heater controls Panel are designed to monitor & control the operations of the heater bundle also to ensure the safety of the equipment and operations. The control logic can be either ON/OFF (contactor) or regulated (Thyristor) or combination of both in a single panel. The control panels can be installed in both safe area & hazardous area by following respective design guidelines & certification requirements. The Control Panels are provided with various indication systems such as Power ON, Heater ON OFF, Trip, High Temperature etc for comfortable handling of the process. The Temperatures of Elements, Process fluid & other areas (with sensors) are displayed on the Panel for better monitoring & awareness. Control Panel will also have safety interlocks such as high element temperature, Earth fault, process over temperature etc along with Emergency stop access for the safe operation and control.

Advantages

• Heaters can be used for quick heating of small volume storages as well as for heating large volumes with longer operational hours
• Widely used for heating high viscous fluids ( Bitumen, HFO etc) and reduce the viscosity before pumping out
• Environment-friendly design. No hazardous gas/smoke/ emission from the system.
• Precision Temperature control
• Can be accommodated in small footprints.
• Custom designed to meet specifications.
• Highly energy efficient and provide maximum dielectric strength.
• Compatible with standard industry piping and safety standards.
• Reliable design.
• Easy to operate and maintenance-friendly.
• Energy Saving.
• No need to drain the tank for any repair/replacements in case of indirect Immersion Heaters.
• Heating Elements: Mineral filled insulated Heating Elements or Tubular heating Elements with Ni-Cr (80-20) as heating Coil and suitable outer sheaths.
• Protections & control: Element Skin Temperature Control, Process Temperature Control, Earth Leakage Protection Overload Current Protection, Temperature Class Protection ( for Hazardous area only)

Application

• At large Storage Tanks for preheating of thick fluids.
• Oil Heating (crude, Thermic fluids, and other Process fluids etc in storage tanks).
• Water heating applications & vaporizer System.
• For reducing the viscosity of the fluid and make it suitable for pumping out.
• Steam Boilers.
• Oil cooling systems & compression packages
• Edible oil heating for food industries.