CALCIFIRE reclamation technology enables most chemically bonded sand to be efficiently reclaimed to a quality equalling or exceeding new sand quality.
CALCIFIRE systems are also available for reclaiming clay bonded sand (green sand)
.The CALCIFIRE design features combustion of the binder material in a direct-fired fluid bed chamber which, unlike competitive units, introduces sand from the top and provides full fluidization wall-to-wall. Air and natural gas are introduced automatically through special distributor tubes as needed to start combustion. Gas levels are then reduced by PLC controller to the minimum amount necessary to maintain the preset bed operating temperature. Because most of the fuel for combustion is often the binder material itself and because combustion takes place directly within the fluidized sand, gas consumption and operating costs are kept low. Additional gas or oxygen can be added when higher temperatures are desired. Heat-resistant steel and ceramic fiber insulation eliminate the need for costly ram-up type refractory linings, ceramic membranes or temperature-resistant moving mechanical parts. Without a lining to preheat, the unit can achieve working temperature in minutes, not hours. Sand flow through the fluid bed is easily regulated for desired effectiveness. Sand can be reused in molds or cores at costs competitive with new sand costs in most areas.
The CALCIFIRE unit is often only a part of a complete reclamation system. We regularly supply the following system components:
 |
1. HLD
Lumpreducer |
Dependable offers the CALCIFIRE with throughput capacities from ½ tph (.46 mtph) to 5 tph (4.5 mtph). The CALCIFIRE unit may be supplied as a stand-alone system, or as part of a larger system, integrated with other reclamation functions as required.
source: http://www.dfrc.com/sand/sand4.php 14mar2006
Dependable Foundry Equipment Company, a division of Tromley Industrial Holdings, Inc. of Tualatin, Ore. also employs a gas-fired fluidized bed in its Calcifire® sand reclamation unit. Instead of an indirect-fired heat exchanger, the Calcifire incorporates a direct firing concept in the fluidized bed. "Direct firing eliminates any problems with heat exchanger burn-out," explains Bill Zachary, senior vice-president, Dependable Foundry. "We can also reach higher temperatures. You need 1,300 to 1,400 degrees fahrenheit to burn off the binders and achieve emissions at or below EPA standards, but the Calcifire can operate as high as 1,700 degrees."
The Calcifire does not employ moving parts or ceramics; high-alloy steel in the combustion chamber reduces the maintenance normally associated with refractory material.
By using direct gas firing, the calcining process is especially effective on both green sand and chemically bonded sands. Heat-up time is short--from ambient to calcining operation levels in 60 minutes or less--and energy efficiencies are optimized by precise control of gas input to compensate for fuel content in the waste sand. Capacities range from one-half to five tons per hour.
A Calcifire unit was recently installed at Pacific Steel Foundry in Berkeley, Calif. "They love the idea that it doesn't need any attention," Zachary says. "They lock it up in a room, feed it used sand and leave it alone to do its job."
"We've found that the chemical binders in the foundry sand can provide a major source of fuel," says Brent Gudgeon, president of Gudgeon Brothers. "Using the binders as a supplemental fuel source during the treatment stage, we can get up to 18,000 btu per pound of sand, cutting the fuel consumption to a fair degree." [Note: This comment is regarding the recycler of another company, but the same thing applies to Calcifire technology.]
source: http://aga.activematter.com/Template.cfm?Section=Past_Issues1&template=/ContentManagement/ContentDisplay.cfm&ContentID=1768 14mar2006
|
To
send us your comments, questions, and suggestions click
here |