Thoreson-McCosh Inc
EDITION 05/07/10
22
IB201001.doc
SECTION 10.4 DESICCANT BED RECHARGING PROCEDURE
FOR TD-12 THROUGH TD-360
Read instructions completely before attempting to remove the beds.
1.
Set Off/Auto/On switch to On, Set key switch to “Adjust Setpoints”.
2. Remove side panels.
3.
Follow the procedure in Section 8.2 “Forcing a Bed Index”. When the beds are clear of
the manifolds, remove power from the dryer.
Note:
Do not turn the dryer off with the OFF/AUTO/ON switch. The manifold will clamp up
against the beds.
4. Loosen the band clamps that hold the bed tight up against the turret plates, and remove
the bed from the unit. Remove the band clamps
5. Apply power and repeat items 3 and 4 until all the beds have been removed.
Note:
On some units, The bed turret assembly can be manually rotated if care is taken to
rotate them slowly, and always in a left to right direction.
Inspect the center cavity at the top of the bed for any quantity of beads, which may indicate
a damaged inner perforate screen.
Inspect the bottom part of the bed for the presence of any loose beads, which may indicate
a damaged outer screen. If when the beds are refilled and there is evidence of bead
leakage, the bed must be repaired or replaced.
To replace the desiccant:
a) Remove the bed bead plate to gain access to the desiccant.
b) Dump the desiccant beads out and vacuum the remaining beads out.
c) Fill the beds with new desiccant - use only 4a type 8 x 12 size (0.080" diameter)
desiccant beads. Fill beds as full as possible. Rock or vibrate the beds to promote
settling of the beads. Add more desiccant to fill the beds and pack tight without
breaking beads.
d) Apply high temperature sealant (G.E. silicone RTV-106n sealant is recommended)
and secure bed bead plates to beds.
e) Reverse the bed removal procedure to replace the beds. Lift the beds into the dryer
with bed bead plates up and positioned outward from the shaft. Make sure that the
bolts for the band clamps are not strait out from the shaft. (The bolts can catch on
frame parts and stall the rotate motor)
f) Secure the beds tight against the turret plate with the band clamps.
g) Start the dryer and let it operate for a few bed shift cycles while inspecting for leaks
at the upper and lower bed seals.
h) Shut off dryer and install side panels.
i) After approximately 1-2 weeks of dryer operation check the bead level and add more
desiccant if needed.
