The All-In-One Heater Kit is a complete system that can provide direct heat to the asphalt tank, while also supplying hot oil for the plant. The primary feature of the system is the drywell-style electric heating elements that provide and maintain heat to keep liquid asphalt cement at the desired temperature. At the same time, the system circulates oil through scavenger coils and thermostat-controlled electric booster heating elements to provide hot oil to heat jacketed lines, pumps and valves, drags, silo cones, and other plant components. The scavenger coils allow for quick heat, while the booster coils sustain it for pinpointed locations. Booster elements also can elevate the oil temperatures above the controlled asphalt storage temperature, if higher-temperature hot oil is required. The system provides 100%-efficient heat over its lifetime (often 30 years or more), as it reduces emissions and the associated need for expensive stack permits at the plant. Using PHCo’s unique Lo-Density patented Coil-Lock-design heating elements, which reside within a drywell, the units dissipate controlled heat as low as three watts per square inch on the heater’s sheath, eliminating coking or damage of the asphalt cement and transfer oil. Because the drywell-style elements are accessible from outside of the system, they also may be serviced without draining the tank.
Each All-In-One Heater Kit is a complete system that includes a high-temperature centrifugal pump that provides flow up to 85 gpm at 140 ft total head. The pump is skid-mounted and pre-plumbed, complete with shutoff valves and strainer. It includes a properly sized, vented expansion tank with a sight glass and a low-level shut-off switch. Like all fluids, heat transfer oil expands when heated. The expansion varies with the temperature to which it is heated. For example, 100 gallons of oil at 50°F will expand to 114 gallons when heated to 450°F. The expansion tank permits expansion of oil as it is heated, without exposing hot oil to air. It functions as an oil seal to accommodate the increased volume of expanded oil in a quantity of colder oil, which comes into contact with a limited amount of air. 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 to provide a means for the escape or intake of air as the oil level in the tank rises and falls.
The system includes 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. PHCo All-In-One Heater systems are completely pre-wired, pre-plumbed, and ready for installation. Standard models come in 60, 100 or 125 kW total rating; custom sizes are available.
As an added benefit, the system has interlocking capability with other equivalent or larger electric users in the plant, to minimize excessive demand charges. For example, if an exhaust fan starts up at the plant, the All-In-One Heater shuts off, reducing overall energy consumption. The circulating pump will continue to run, however, and scavenge heat from the liquid for the plant’s hot oil needs.
