 | The University of Virginia record February, 1908 |  |
ENGINEERING LABORATORIES.
The Sinclair Laboratory for work in Strength of Materials.—This
was founded on the original donation of Mrs. John Sinclair, of New
York City, as a memorial to her late husband. The collection has since
been considerably enlarged. It contains Riehle and Olsen machines, each
of 100,000 pounds capacity, arranged for tensile, compressive, and transverse
tests; an Olsen torsion machine of 50,000 inch pounds capacity; an
Olsen compression machine of 40,000 pounds capacity; a Ewing tester for
the elasticity of rods; hand machines for testing rods and wires and small
specimens of timber and cast iron under transverse loads; Fairbanks and
Olsen cement testers of 1,000 pounds capacity each; apparatus for torsional
tests on both long wires and short wires; together with the necessary
accessory apparatus for utilizing these machines.
The Scott Laboratory of Electrical Engineering.—This laboratory
was equipped and endowed by Mrs. Frances Branch Scott, of Richmond,
Va., as a memorial to her late son, an alumnus of this University.
and calibrating them, galvanometers of the best modern types, standard
cells and resistances, standard condensers, and all other necessary apparatus
for minor tests, it contains numerous pieces of the very best construction.
Such are the Wolff potentiometer, the Siemens and Halske
Double Bridge, the Magnetic Induction apparatus, the Duddell Oscillograph,
the Station Photometer, and so on. It contains also a number of
direct current generators and motors, a two-phase alternator, induction
motors of two and three phases, several pairs of transformers, and all the
apparatus used in testing such machines.
The Steam Engine Tests are made on the high-speed Ball engine,
which operates the shops. This motor has been specially equipped for the
purpose. It receives steam from the main line through a Sweet separator;
humidity determinations are thus made twice—once by a separating calorimeter
before the steam enters the separator, and again by a throttling
calorimeter as it enters the cylinder. It is fitted with proper indicators,
and permanent indicator rigging so that at any time cards may be taken
and the indicated horse-power determined. In like manner a rope friction
brake is so arranged that it may be at once applied for the determination
of brake horse-power. Connections are so made with a Wheeler surface
condenser that the engine may at will be operated either condensing or
non-condensing. Provisions are made for measuring the temperatures and
the amounts of the condensation water and the condensed steam produced
during the run. With these data a complete heat balance of the experimental
run is attainable.
For Steam Boiler Tests the boilers of the University heating and
lighting plant are available. The department is equipped with the necessary
apparatus—thermometers, gauges, steam calorimeters, fuel calorimeters,
gas analyzers, scales, tanks, and so on. Students of Mechanical
Engineering are taught by practical lessons in the boiler room the standard
methods for boiler trials, and the class makes each session at least one
complete trial.
The Gas Engine Tests are made on an Otto machine of 15 I. H. P.
and 12 B. H. P. This also is provided with its friction brake, indicator
rigging, and indicator. The cooling water is run in from calibrated tanks
and provision is made for observing not only its amount but the initial
and final temperatures. Gasolene or alcohol is used as fuel, and is run
in from a graduated wrought-iron bottle, so that the amount consumed is
determined. The heating power is obtained by an independent test with
a Rosenhain calorimeter. Samples of the burnt gases are drawn from the
exhaust pipe and analyzed in an Orsat gas apparatus. The temperature of
the exhaust will be determined by a platinum resistance thermometer
inserted close to the exhaust valve. With these data and the observed
numbers of revolutions and explosions the heat balance is worked out.
The Refrigerating Tests are made on a Remington Ice Machine of
one ton capacity. This is an ammonia compression machine driven by an
electric motor. Instead of brine, plain water is used, heated by a steam
jet to 100° and then cooled down to 40° by the machine. A run is first
made with the pipes empty in order to determine the friction horse power.
The ammonia is then turned on and the run is made under load. In both
cases the power consumed is measured both by watt-meter and by ammeter
and volt-meter readings. The tanks are accurately calibrated and
careful measurements of the temperature are made through the run.
Indicator cards are also taken from the ammonia cylinders and the number
of revolutions is registered by counter. With these data the mechanical
and thermodynamic performance of the machine are figured out.
In the Road Material Tests the machines used are mainly those
devised by Dr. Logan Waller Page, director of the United States office of
public roads. For measuring the strength of the stone cylindrical samples
are cut out with a diamond drill and tested under impact and in the
40,000-pound compression machine. The resistance to abrasion is measured
on fragments of the stone, rotated in heavy cast iron cylinders
mounted on their diagonals. The binding power of the dust is measured
by impact tests on cylindrical briquettes formed under heavy hydraulic
pressure. The dust for these briquettes is produced in a ball mill fed with
fine stone broken in a small crusher. This part of the testing outfit has
been only recently installed, largely by the generous aid of Dr. Page. It is
hoped that useful experimental researches on the road-building rocks and
gravels of Virginia may be carried out with it.
| The University of Virginia record February, 1908 | |