Lo-Density Hot Oil Circulating Heater systems provide automatically controlled, even-temperature heat-transfer fluid. The systems offer unique benefits for asphalt plants: lower operating costs, improved product quality, reduced maintenance, significantly longer heater life, and enhanced sustainability. With the PHCo indirect heating systems, heat from electric energy is transferred to the oil, which then carries it to the area or process where it is needed. Using PHCo’s Lo-Density patented Coil-Lock-design heating elements, the units dissipate controlled heat as low as eight watts per square inch on the heater’s sheath, eliminating coking or carbonization of the transfer oil. Because the drywell-style elements are accessible from outside of the system, they also may be serviced without draining the heater.
Each heater is a complete system that includes a properly sized, vented expansion tank with a sight glass and a low-level shut-off switch. The expansion tank permits expansion of oil as it is heated, without exposing hot oil to air; functioning as an oil seal to accommodate the increased volume of expanded oil in a quantity of colder oil. The low temperature of the oil seal will contribute to the long service life of the oil. A secondary function of the expansion tank is provided as a means for the escape or intake of air as the oil level in the tank rises and falls.
The system also includes an exchanger built to ASME standards, covered with high density insulation and an aluminum jacket. There is a motor-driven, special high-temperature centrifugal pump for circulating heat transfer oil, a UL-listed industrial control panel in a weatherproof enclosure with standards that include a programmable time clock for early morning startup, main indicating controls, and over-temperature controls. Also contained in the package are additional convenient features on these heaters, including a strainer for easy cleaning, shut-off valves for the system and the fill lines, and strategically located air purge valves to assist in filling the system. PHCo Hot Oil Circulating Heater systems are completely pre-wired, pre-plumbed, and ready for installation.
- Flange/Heater Materials – mild steel and various grades of stainless steel
- Sheath Thickness – up to .300 in. wall thickness for durability and corrosion resistance
- Kilowatt Ratings – Up to 1,000 kW
- Watt Densities – up to 20 watts per square in.
- Voltages Available – up to 600 VAC, single or three phase
- Immersion/Vessel Length – up to 20 ft.
- Terminal Enclosure – Moisture resistant standard. Some sizes available as explosion resistant
- Open Coil Elements – Pipe insert type, drywell elements for ease of service
