ORNL-4191 - the Molten Salt Energy Technologies Web Site

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1966
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C HEAT TRANSFER COEFFICIENT (REhSFD CA ClJLAl ION)
HEAT TRANSCER CCJFFFICIENT [OQIGINAL CALCULATION!
- HEAT TRANSFER INDFX
Fig. 1.12. Observed Performonce of MSRE Main Heat Exchanger.
Coefficients were computed from these data by a
procedure used since the beginning of power
operation and by a revised procedure whose
principal difference is that it uses only the most
reliable thermocouples. Coefficients computed
both ways are shown in Fig. 1.12 along with the
heat transfer index. The coefficients and t.he
index indicate that the performance of the heat
exchanger has remained practically unchanged.
(The downward shift in the heat transfer index in
March 1967 is the result of revising the tempera-
ture biases in the computer.)
Main Blowers
C. 1-1. Gabbard
The rebuilt main blowers, MU-1 and Me-3, have
now accumulated 4640 and 4220 hr of operation,
respectively, since they were installed in October
and November 1966. The main bearing on MB-3
was replaced in early March after 1800 hr of
operation, when the vibration amplitude started
increasing. The balls and races of the hearing
were severely scored and pitted. The replace-
ment bearing also gave an indication of trouble
and was scheduled for replacement during the run
11 shutdown. However, the problem turned out to
be the result of a loose vibration pickup.
A complete inspection of the blowers and drive
motors was made after the run 11 shutdown. Both
blowers were again in excellent condition after
3585 and 3162 hr of operation, with no indication
of cracking in the blades or hubs. The slip rings
and brushes on the drive motors had become scored,
and the motors were removed for repair. The re-
T
1067
pairs included refinishing the slip rings, replacing
the brushes and bearings, and balancing the
rotors. Vibration pickups were added at each
motor bearing, and filters were installed to protect
the slip rings from dirt and grit. When the
blowers were test run, there were excessive vibrations
on the drive motor of main blower 3. The
motor vibration had been satisfactorily low when
the motor was loosened on its mount, indicating
that the motor was not badly unbalanced. ‘The
rotation speed of the motors was found to be very
near the natural frequency of the motor mount.
The vibration amplitude was reduced to an acceptable
level (below 1 mil) by stiffening the mount.
Insulation Dust in the Reactor Cell. -- During
observation in the reactor cell between runs 11
and 12, a nonuniform coating of white material was
seen on most of the horizontal surfaces of the reactor
cel.1 (see Fig. 1.13). Samples of the white
coating were obtained with long-handled tools
and identified as being mostly A120, (insulation).
Attempts to further identify it as one of the two
specific types of insulation known to be in the
cell were unsuccessful. The possible sources are
the insulation covering the fuel pump and overflow
tank, the reactor vessel, the fuel drain line,
or the fuel line under the heat exchanger. The
drain-tank cell was also viewed, but no covering
of insulation dust was noted.
Radiator Ene losura
M. Richardson
The brake shoes in the brakes of the radiator
door lifting mechanism were found to be worn and