ORNL-1771 - Oak Ridge National Laboratory

ANP QUARPERLY PROGRESS REPORT
Hydraulic Motor Bump Drives
J. A. Conlin
Aircraft Reactor Engineering D iv i s ion
Two types of hydraulic motors have been found
to be suitable for use as in-pile pump drives. The
first, a gear-type motor rated at 1.75 shp at 3500
rpm, WQS operated at 6000 rpm for 500 hr under a
light load (about 0.08 shp) that was obtained by
coupling the motor PO a small air blower. Upon
completion of the test the motor was disassembled
and was found to be in good condition. The rubber
lip shaft seal had worn a slight groove in the
shaft, and a carbon-like deposit which had ac-
cumulated on the shaft just outside the seal caused
the seal to stick slightly after it had been idle for
a prolonged period. However, throughout the test,
se~l leakage was i?egligible. The only other indication
of wear was a slight scoring on the gear
sides adiacent to the shaft end of the motor.
The second motor, an axial-piston type rated at
3.8 shp at 6060 rpm continuous duty, was run for
100 hr at 6000 rpm. Operation WQS completely
satisfactory, and, since this motor is rated at
6060 rpm, further testing was judged to be un-
necessaiy.
The nxial-piston motor was chosen for in-pile
ssrvite, since it is considered to be the more
reliable unit. Throughout these tests, hydraulic
ail with a viscosity of 155 SSU (seconds Saybolt
wniversal) at 100OF and a viscosity index of 100
wa5 used. It should be noted that during initial
testing nf the gear-type moto:, oil with a viscosity
of 290 to 325 SSU at lOO'F was used, and, as a
result, excessive overheating of the motor occurred
to the extent that the shaft turned blue. Despite
this, the motor completed the test satisfactorily.
f 0 R C E D-C I R C Ub A T 10 M CO R R 0 S I0 N L 0 8 P 5
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laaconel Loops
W. 63. Twnnell
Aircraft Reactor Eng i neer i ng Divi si on
W. IC. Stair, Consultant
J. F, Bailey, Consultant
University of Tennessee
I Re previowsly described, small, Inconel, forced-
circulation loop designed to have a temperature
differential of 135OF has been operated for a total
of 141 hr with NaF-ZrF,-IJF, (50-46-4 mole X)
at an apparent mass flow rate of 400 to 450 Btu/hr
with a temperature differential up to 300°F.3 The
38
fluid velocity in the loop normally was maintained
OS about 1.7 fps at a temperature gradient of 165OF.
Termination of the test resulted from a short in
the motor leads and subsequent rupture of the
heated section of the loop. The test facility,
shown in Fig. 3.4, is being rebuilt and is approxi-
mately 80% complete. The final design conditions
are presented in Fig. 3.5, Reports which give a
detailed presentation of the design and an analysis
of the initial operation are being prepared.4t5
In the design of the loop for electrical-resistance
heating, a resistivity value' of 98 phm-cm was
used for Inconel in computing the necessary length
of the resistance-heated tube. However, data
obtained during the loop operation indicated that
the actual resistivity of the lnconel was about
70 to 80 pohm-cm. To resolve the discrepancy, a
duplicate of the heating section nf the loop WQS
filled with NaF-ZrF,-UF, (50-46-4 mole X) and
alternately heated and cooled while accurate
potential and current measurements were mode.
Sixty-two measurements were made in the tempera-
twre range of 800 to 1600°F, and the average
resistivity of the Inconel was found to be 75
pohrn-cm.
A program is under way for the design, con-
struction, and operation of two series of forced-
circulation loops for studying the effect of temper-
ature gradient und fluid velocity on the phenomenon
of mass transfer in lnconel systems containing
fluoride mixtures at elevated temperatures.' The
requirements of the .two series of loops are a
Reynolds number of 10,000 with temperature gradi-
ents of 100, 200, and 300°F and a temperature
gradient of 20O0F and Reynolds numbers of 800,
3,000, and 15,000. The maximum fluid temperature
is specified CIS 1500°F, and the Reynolds numbers
are to be evaluated at that temperature. The loops
are to be constructed of lnconel twbing. The
maximum tubwall temperature is to be 1700°F,
and the surface-to-volume ratio is to be held
essentially the same for each loop.
3W. C. Tunnoll, W. K. Stair, and J. F. Bailey, ANP
Quar. Prog. Rep. lune 10, 1954, ORNL-1729, p 21.
4W. K. Stair, The Design of a Small Forced Circu-
lation Cowusion Loop (to be published).
'!Y. C. Tunnell, Operation Re ort o/ the First Small
ATV Study Loop (to be published?.
61nternatianal Nickel Cn,, Properties o/ Some Metnls
and Alloys.
7W. D, Manly, High Flow Velocity and High Temper-
ature Gradient Loops, OKNL. CF-54-3-193 (Mar. 18,
1954).