When Bremer Mfg. made the decision to switch completely to electric furnaces 15 years ago, it made a strategic decision to reconfigure its melting area as well.
The decision was to move the melting furnaces from the end of the molding line to a location closer to the pouring line. The result was tighter process controls. We originally made the decision to go electric so it could minimize the gas absorption in the melt that is inherent with gas or oil furnaces. As long as new equipment was being added, we decided to move the furnaces so the molten aluminum would spend less time being exposed to air while transporting it to the pouring line.
With having the molten metal adjacent to the molding line, we now have very good control over the metal. We are able to pour at a consistent temperature and maintain it. We started the conversion by adding a 1200-lb. electric furnace from Thermtronix Corp., Adelanto, Calif. Since that time, Bremer has steadily been adding equipment and now has 16 2300- lb. capacity melting furnaces (from Thermtronix), the newest of which is three years old.
Bremer’s furnaces feed five green sand molding lines used to produce castings for combustion engine components and for use in the architectural lighting industry. Bremer runs two shifts each day, reloading the furnaces at the end of the second shift and recharging when they are 2/3 empty. The facility remelts all of its metalcasting facility scrap, but none of the machine scrap, with ingot and scrap mixed 60/40 into the melt.
The furnaces are brought up to temperature an hour before pouring starts for the first shift and are recharged throughout the day to keep enough molten metal in supply for second shift.
Bremer, which is primarily a Tier 2 supplier but does some work as a Tier 1, has 120 employees, 30 of which are dedicated to the melting and molding. Four molding lines are typically run during a shift with one molder for each line as well as two employees pouring for each line and two more in shakeout. The metalcasting facility melts about 375,000 lbs. of aluminum a month.
As part of the tight process controls that Bremer keeps, degassing is done with argon by a manual lance, although future plans may include investing in a mechanical degassing system.
Following degassing, the molten metal has a short trip to the pouring lines, which are no more than 15 ft. away. As the molds come off the molding machine, they are placed on a rolling conveyor system that snakes through to the shakeout area. Feel free to head over to our Aluminum Sand Castings page to learn more about our capabilities in more detail.
– Dave Bremer