TRAVELING BILLET HOMOGENIZING FURNACE
This case study describes equipment installed in a plant located in
the Northeastern United States of a major worldwide aluminum
billet producer. For more information on Aluminum heat
treatment check out http://www.secowarwick.com/aluminumprocess.html
The original furnace equipment at this
plant were two typical car bottom type homogenizing furnaces.
Each furnace had its own powered load car, which the billets
were loaded onto and then driven into the furnace. Both furnaces
were operating at maximum capacity when
increased production requirements forced the plant to add an
additional furnace. The two existing furnaces were tucked in a
corner of the plant site which made it impossible to add the
same type of furnace. So other options were investigated.
 |
|
Traveling Log Homogenizer - Click
on the photo for our Aluminum Homogenizing Furnace
Brochure in .pdf format. |
Instead of buying new equipment, a sister plant (which was to
be shut down) had an existing Traveling type homogenizing
furnace. This type of furnace provided solutions to many of the
space problems. Even though it had to be transported and some
rebuild work was required, the use of this furnace made good
economic sense to the producer.
SECO/WARWICK was contracted to rebuild the
furnace. The furnace was disassembled, transported and rebuilt on-site.
During the rebuild, the furnace received some modifications in
the floor seals and the furnace drives.
The plant was very happy with the decision.
In fact, three years later when they required an increase in
furnace capacity, the decision was made to purchase a new
Traveling furnace, incorporating the design changes learned from the first
Traveling furnace experience.
Making the Decision
Limited plant floor space—The
utilization of the Traveling furnace provided twice the loading
area in half the floor space, since the furnace moves from one
loading area laterally to the second loading area.
Loading and unloading consideration-The
existing load cars for the car bottom furnaces were elevated off the floor, requiring an
overhead crane to load the large diameter billets. This was a
very time consuming process to fully load each furnace car.
Since the Traveling furnace load base is floor level, each of
the two load bases can be loaded or stacked with a fork truck.
The loading base was designed with steel cover plates to
withstand not only the billet load, but also the weight of the
fork truck. Using a fork truck provides a safer alternative for
the plant operators because overhead cranes were no longer
needed, and the potential of a billet rolling off an above floor
level load car was reduced. The loading and unloading of these bases can now be
accomplished in half the time. Placing thermocouples in the load
is made easier since the load is just above floor level.
The previous operation required a lift of some kind to reach
the billets when they were stacked on a load car.
Performance improvements-The performance
improvements are somewhat difficult to measure when comparing
the existing furnace to a new furnace. But there are some major
differences to point out:
With the conventional car bottom type of
furnaces, the load car has to be removed from the furnace,
unloaded and then reloaded, and is then driven back into the
furnace. For this time cycle, the furnace has lost a majority of
its heat from the previous load, so to bring the furnace back up
to temperature will take additional time.
When the new Traveling furnace has completed its
cycle, the furnace doors open and the furnace travels from one
loading base to the next. The next base is being loaded while
the other load is under heat. The result is a faster load change
with an already heated furnace. Once the furnace has moved into
position on the adjacent load base, the heating cycle begins.
With the Traveling furnace design, the
plant sees a 20% reduction in their overall heating time.
CASE STUDY SPECIFICATIONS
Billet Material Specifications:
- Batch Load Capacity: 191,505 kg (422,190 lbs) Maximum
- Billet Diameter: 228.6 mm (9.0 in) Minimum, 473 mm (18.625 in) Maximum
- Billet Length: 4,420 mm (174 in) Minimum, 5,892 mm (232 in) Maximum
Furnace Specifications
- Furnace Design Temperature: 649 degC (1,200 degF)
- Furnace Operating Temperature: 543 degC (1,010 degF)
- Load Temperature Uniformity: +/-
8 degC (+/- 15 degF)
Special Features:
- Movable Internal Baffles
- Load Base Sealing System
- Mesh and Mortar Insulation System
- Special Design Load Bases
- Intellution™ operator interface software
SUMMARY
Every plant site has its own unique
requirements. This customer has been very satisfied with the Traveling furnace
design and when the need arises will most likely select the same
style of furnace for future expansion.
R1 12/7/2004 Updated source code
R2 12/12/2005 Updated author reference
| 
