Visit the Product Innovations Archive at
www.moderncasting.com
New ProductConductive Troughs Improve Melt Transfer Efficiency Trough/launder systems are com-
monly used in aluminum metalcasting facilities to transfer molten metal be- tween furnaces and pouring stations. Open troughs result in temperature losses. Trough covers and heated trough covers reduce these losses. Radiant heat transfer, which is typical in traditional heated covers, increases oxidation losses, requires frequent skimming and cleaning, and results in substantial thermal stratification, where a warm, less dense layer of molten metal overlies a cooler, denser layer. In a new concept from Apogee Tech-
nology Inc., Verona, Pa., conductive troughs (CTs) are heated using high intensity resistance elements embed- ded in baffle and side pocket panels (BSPP) integrated into the sidewalls of the trough. This concept relies on thermally conductive BSPP sections impervious to metal attack through which heat transfer occurs by subsur- face conduction and convection (Figs. 1a and 1b). The CT eliminates thermal stratification (Figs. 2a and 2b), and melt loss is negligible. Skimming is optional. The use of CTs has demonstrated
energy requirements lower than 0.5 kW-H/ft. and precise temperature main- tenance or increasing temperatures during transfer at the rate of 1.3F/ft. at a flow rate of 19,000 lbs. per hour. A radiantly heated trough cannot ef- fectively raise temperature and requires more than twice the energy. Expected
PRODUCT INNOVATIONS
Figs. 1a and 1b. Metalcasting facilities can utilize a combination conductive trough with an integral baffle side pocket panel-heated dip-out well in their melt department.
CT refractory life is greater than tradi- tional radiantly heated troughs because excessive temperatures at and above the metal line are avoided. Heating ele- ment life is greater than two years and replaced without affecting production.
The receiving end of in-plant trough
transfer is either a holding furnace or basin from which metal is drawn for pouring. BSPP-heated basins and fur- naces of 1,000- to 9,000-lb. capacity offer up to a 12:1 advantage in energy efficiency over natural gas fired units, unstratified temperature control and minimal melt loss. The impact of re- duced temperature variability at the point metal is cast can be measured in improved recovery and product/pro- cess reproducibility. A combination CT with an integral BSPP-heated pouring basin has been proven in production. CT and BSPP holding, which benefit
Figs. 2a and 2b. Thermal stratification present in radiant troughs (right) is avoided with conductive troughs.
MODERN CASTING / December 2010
from the availability, versatility and pro- jected stability of electric power compared to natural gas, have the potential to increase energy efficiency, reduce melt loss, reduce refractory repairs and lower manufacturing costs, while improving the workplace environment.
MC Visit
www.apogeetechinc.com for more information. 45
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60