Recuperative furnace reduces energy consumption.

Because the amount of energy required to heat metal to a molten state can be high and costly, recuperative systems often are used to avoid wasted energy. Principally used in fuel-fired applications, recuperative systems take waste energy leaving the furnace exhaust and repurpose it to preheat either charge materials or combustion air. Morgan Molten Metal Systems (Morgan MMS), Worcester, U.K., offers a recuperative furnace for melting aluminum and zinc alloys that can result in up to 20% fuel savings over an equivalent, nonrecuperative furnace.

The Recuperative Gas Fired Bale Out MK V "R" furnaces, which can be used to obtain an air preheat temperature of up to 482F (250C), use a combination of reduced waste gas loss and better heat transfer through higher velocity and temperature of burner gasses. They offer the following advantages: low energy consumption;

* low casing temperature;

* efficient, high turn-down burner

* accurate metal temperatures through proportional, integral and derivative control;

* interchangeable radiant panels;

* temperature depression for economy and safety.

Greater recovery can be achieved at higher preheat temperatures; however, the recuperator and burner costs associated with achieving this makes the system uneconomic.

The furnace is equipped with a high-performance, low-nitrous oxide, fully-proportioning, nozzle mix, gas burner. Air is delivered to the burner from a compact regenerative blower, the volume of which is regulated by a solid state inverter, thus avoiding valves and linkages. Air and gas are mixed in proportion to air flow, retaining the correct air/gas ratio across the turn-down range.

The burner is designed to keep nitrous oxide emissions to a very low level (less than 130 ppm) throughout the air preheat range. Nitrous oxides, which include nitrous oxide and nitrous dioxide, can be formed in the combustion process of exhaust gases from the disassociation of nitrogen in the air. Nitrous oxides increasingly are seen as harmful to health and the environment and are subject to limits set in the standards of many countries.

With typical forced-air gas burners working at room temperature air supply, nitrous oxides are generally at low levels (less than 40 ppm). However, as a result of raising the combustion air temperature, nitrous oxides increase. Without taking steps to reduce this, unacceptable emissions will arise. Morgan MMS aims to release the same nitrous oxide with its recuperative furnace as a furnace with a normal nonrecuperative burner.

Visit www.morganplc.com for more information.