Download Mixing Using Instructions

Installation of Dry Lining Materials
in Coreless Inductions Furnaces
The Refractory Specialists
A division of P-G Industries, Inc.
AN EMPLOYEE OWNED COMPANY
I. PREPARATION OF THE CORELESS FURNACE
1. Check the coil for electric insulation and any water leakage.
2. Level out uneven diameter of coil with coil grout. Make the wall vertical in order to avoid
any obstacle for the lining growth (no wave formed surface or wrong tapering). Ensure the
coil grout is tapered when using push-out. Note: The thick coil grout layer used for push-out
must be dried at 820°F before installation of the lining. The same holds true for castable
furnace rings and push-out blocks.
3. Carefully apply slip plane material (mica, cloth, etc.). When using sheets, operate with
overlapping joints.
4. The furnace, form and tools must be perfectly clean. Assure that the surrounding area is
clean as well.
5. Assure all workers have emptied their pockets and have no loose articles that may get into the
lining.
II. INSTALLING THE REFRACTORY
Ramming of dry lining materials implies compaction of the loose mass. Compaction can be
accomplished in three ways:
A. Manually with Bosch vibrator
B. Manually with pneumatic vibrator(s)
C. Mechanically with pneumatic internal form vibrator(s)
A. Installation - Manually with Bosch Vibrator
1. Compacting the Bottom
a. For the first layer in the bottom, fill in lining compound to a maximum depth of 6".
b. Ram/compact with spade rammer - three passes minimum.
c. Compact with Bosch vibrator working from the center outwards, overlapping with each
strike. Make a minimum of three passes. We recommend a tube length on the Bosch not
to exceed 40" for best performance.
d. After vibration, scratch the surface to a depth of ½” to prevent lamination.
e. The following layers of no more than 4" are then compacted with above methods.
f. Ensure the final depth is 1" higher than required. This additional 1" of material should be
removed leaving behind a solid, level base.
2. Placing the Form
a. It is essential that the form be level and centered. Use a level and plumb-bob to
accomplish this.
b. Secure the form into place.
Anniston, AL • Chehalis, WA
1-800-446-8769
3. Compacting the Sidewalls
a. The sidewalls are rammed in 3 to 4" layers. The taper section is the most difficult to
reach. When it is necessary, the former has to be split about 8" over the taper section in
order to ensure access to the area with the Bosch vibrator.
b. Each 3 to 4" layer is rammed with a minimum of three passes, then compacted with a
Bosch vibrator with a minimum of three passes. After vibration, scratch the surface to a
depth of 1/2" to prevent lamination.
c. Change the position of the workers systematically around the form.
d. Continue the successive layers with the same method until furnace is full.
B. Installation - Manually with Pneumatic Vibrators
1. Compacting the Bottom
a. Bosch procedure may be used (see above).
b. Bottom plate vibrator method: The lining material is placed into the furnace bottom
allowing for approximately 15% overfill. Care should be taken to generally level the
base before the vibration begins and assure the ground wire probes are above the surface.
c. The base plate is then lowered into the furnace. To prevent damage to the furnace coil,
place a 1" diameter rubber hose around the base plate circumference.
d. Start the vibrator by fully opening the air feed valve and immediately adjust the pressure
until a distinct knocking can be observed. For the correct compaction, it is important that
the pressure/frequency is altered several times during the eight minute operation. This
will ensure that the correct compaction/porosity is developed throughout the whole base.
Constant frequency can form a crust or hard cap on the surface while leaving the area
underneath soft.
e. Gently lift out the base plate with the vibrator running slowly. The segregated top layer
is then removed and the base leveled. Adjust ground wires to the correct height to assure
they come into contact with the form.
f. Loosen the base refractory (scratch 1") in the areas where they will later create a joint
with the sidewalls.
g. If the height of the bottom is too low, then the surface should all be loosened to a depth
of 2" and material added and vibrated again.
h. Thick bottoms over 12" should be vibrated in two layers.
2. Compacting the Sidewall
a. Install loose material in a 3 to 4" layer and ram with a minimum of three passes.
b. Continue this process until furnace is full. Note: When filling sidewall layers, be sure to
add material as evenly as possible.
c. Material is now ready for vibration. See procedure for using cross vibrator or Klein
Jolter machine.
C. Installation - Mechanically with Pneumatic Methods
1. Compacting the Bottom
a. Bosch procedure may be used (see above).
b. Bottom plate vibrator method may be used (see above).
Anniston, AL • Chehalis, WA
1-800-446-8769
2
2. Compacting the Sidewall Using Cross Vibrator
a. Place a clean, rust-free 1/4" minimum thick form into the furnace. Center and secure.
b. Fill the sidewalls with lining material. Add material evenly as to avoid segregation.
Once the furnace is full, de-air using a 1/2" diameter rod the length of the furnace. De-air
every 6" to 10" to ensure that any air pockets are removed and bridging is avoided. Top
off the furnace with material.
c. Lower the cross vibrator into the form just below half way down for furnaces with
diameters 3' or less. Vibration time and speed is important and will depend to some
extent on furnace size, air pressure and type of refractory used.
d. Slide the four hardwood timbers between the jaws of the cross, ensuring that the timbers
are resting against the former and not touching any tapered section. Gently pump out the
jaws onto the timbers. Please note: minimum pressure only should be applied to prevent
breaking the hydraulic seals. Tension should now be released from the overhead crane.
e. Open the air valve and run at a low speed for twenty to thirty seconds. Stop, if necessary,
to tighten the cross.
f. The air valve is opened until the correct resonance is observed. This will be apparent
because a distinct and very slight knocking effect will be observed.
g. Vibration should continue for three minutes and then stopped. The surface of the lining
is then loosened and more lining material is added. An additional three minutes vibration
will complete the operation.
h. Before removing the vibrator, attach the overhead crane and release the hydraulic system
by turning the release screw through 180 counter clockwise, followed by a
reintroduction of air. Finally, run a small amount of light oil through the system after
each installation.
3. Compacting the Sidewall Using Klein-Jolter Machine (automatic type)
a. Place a clean, rust-free 1/4" minimum thick form into the furnace. Center and secure.
b. Fill the sidewalls with lining material. Add material evenly as to avoid segregation.
Once the furnace is full, de-air using a 1/2" diameter rod the length of the furnace. De-air
every 6" to 10" to ensure that any air pockets are removed and bridging is eliminated.
Top off the furnace with material.
c. Suspend the jolter in the crane by the three rings that pull in the cylinders.
d. Pull out the spring pins (3).
e. Lower the jolter into the form and allow to rest on the bottom. Remove the three rings
from the crane hook and put the larger ring onto the crane hook. Raise the jolter slightly
off the floor (approximately 1").
f. If the tabs on the end of the cylinder are not in contact with the form, the jolter needs
adjustment outward. This is done by loosening the two bolts on top of the cylinder, then
sliding the entire cylinder outward. Note: It is not necessary to have a symmetrical
interval of the cylinders.
g. At the beginning (just off the floor), the jolting time should be four minutes. After the
initial four minutes, the jolter should be raised no more than 4" per minute. Stop
vibrating 10" from the top of the form.
h. Material should be added continuously during vibration.
i. The jolter should be protected from dust and moisture. If possible, it should be covered
during storing. Every time before you start the jolter, oil should be added into the air
tube.
j. Technical data: Type 60-K, at six bar quantity of air 1/min 780, vibration/min. 2200,
energy N 1830, impulse cm kg 8.40.
Anniston, AL • Chehalis, WA
1-800-446-8769
3

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