The apparatus consists of mica heater sandwiched between two identical
composite slabs on either side. Heat produced by heater flows axially on
both the sides. Thermocouples are introduced at the interfaces of slabs to
determine the temperature gradient.
1. Composite wall.
a) M.S. plate 250mm dia. And 25mm thick.
b) Brass plate 250mm dia. And 10mm thick.
c) Bakelite plate 250 mm dia. And 10mm thick. Identical slabs on both sides of heater are provided.
2. Heater-Nichrome wire heater, wound on mica, sandwiched between aluminum plates.
3. Water cooled heat sinks at the end of composite slabs.
4. Enclosure with front Perspex to provide undisturbed conditions.
5. An instruments panel comprising of -
a) Voltmeter and Ammeter for heat input measurements.
b) Dimmer stat to control heater input.
CONCENTRIC TUBE HEAT EXCHANGER:
SPECIFICATION:
The unit consists of a copper tube inside a G. I. pipe. The hot fluid is hot
water obtained from a water heater, which flows through the inner tube and
cold fluid i.e. cold water flows through outer tubes. The hot water flows
always in one direction while direction of cold water can be changed parallel
or counter to hot water so that unit can be operated as parallel or counter
flow heat exchanger. .
3) Water heater to obtain hot water, 3 Kw capacity with safety thermostat..
4) Thermometers to measure inlet and out let temperatures of hot and cold water..
5) Measuring flask and stopwatch for water flow measurement
.
CONDENSATION IN DROP AND FILM FORMS:
SPECIFICATION:
The apparatus consists of a transparent glass cylinder at the top of which
two condensers hang and steam is admitted at the bottom. One of the
condensers is provided with chrome-plated surface for dropwise
condensation and other with natural surface finish to promote filmwise
condensation. Water is circulated through the condensers from common
inlet. .
1.Steam Generator - With 1.5 kw capacity water heater and heater control and pressure relief valve. Steam dryer to remove water droplets..
2) Condensers -19 mm O. D. 150 mm long, chrome plated - 1No. (for condensation in drop forms) - 19 mm. O.D. 150 mm. long, natural finish – 1 No. (for condensation in film forms).
3) Rotameter - 25 - 250 lph for cooling water flow measurement..
4) Pressure Gauges-0 to 2.1kg/sq. cm
.
CRITICAL HEAT FLUX APPARATUS:
SPECIFICATION:
The apparatus consists of a nichrome wire immersed in water. The nichrome
wire is heated by passing current through it. Input to nichrome wire is
controlled by a dimmer stat. As one goes on increasing wire input current
increases and at critical heat flux the wire brakes, which is measured on the
meter .
1. Glass bowl housing water, test heater and water heater..
2. Dimmer stat to control input to test wire.
3. Voltmeter & Ammeter to measure input to test wire.
4. Thermometer to measure water temperature.
5. Magnifying glass & lamp for visualization of boiling process.
CRITICAL RADIUS OF INSULATING MATERIAL:
SPECIFICATION:
The unit consists of G.I. pipes provided with plaster of paris insulation of
different thickness on outside surface. Four pipes are provided with heater
inside having input control. Input to heaters is measured by common
voltmeter and ammeter.
2. Insulation over the pipes of different thickness.
3) Controls and Measurements.
i) Dimmer stat to control input to the heaters - 4 Nos.
ii) A voltmeter and ammeter to measure inputs to heater.
iii) Digital temperature indicator to measure temperatures across insulation.
iv) Necessary switches and controls.
EMISSIVITY MEASUREMENT APPARATUS:
SPECIFICATION:
The apparatus consists of a test plate and a comparator plate. A black plate
is used as a comparator for test plate. When all the physical properties,
dimensions and the temperatures are equal, heat losses from both plates
will also be the same, except radiation losses. Hence the input difference
will be due to difference in emissivity.
Both the plates are kept in a panel enclosure with perspex front and are given inputs through separate dimmer stats so that temperatures of both can be kept equal. Thus emissivity can determined over a wide range of temperatures.
1) Test plate and Black plates - 160 mm. dia, aluminium plates, mounted in panel with mica heater inside.
2) Instrumental panel consisting of .
a)Voltmeter and Ammeter for input measurement to both heaters through a selector switch.
b) Dimmer, 2 amps. Capacity- 2 Nos.
c) Multi channel digital temperature indicator.
FORCED CONVICTION AARATUS:
SPECIFICATION:
The unit consists of a circular pipe, loosing heat by forced convection
to air, being forced through it.
Constant heat flux is added to pipe by an electrical heater, provided with
input control.The pipe surface temperature is measured at various points
along the length of pipe. Temperatures of air at inlet and outlet of test
section are measured.Thus the students can calculate local and overall heat
transfer coefficients in forced convection, at various airflow rates and various heat flux values.
1) Test pipe - 32 mm N B G. I. pipe, 500 mm. long, heated by band heater, out side.
2) Centrifugal blower to force air through test pipe with flow control valve.
3) Variac 2A capacity to control heater input.
4) An orifice meter with differential water manometer.
5) Voltmeter and Ammeter to measure heater input.
6) Multi channel digital temperature indicator to measure various temperatures
.
HEAT PIPE DEMONSTRATOR:
SPECIFICATION:
The apparatus enables the students to study the interesting phenomenon
of heat pipe
& to compare its performance with other pipes. The apparatus consists of
a heat pipe made up of stainless steel, evacuated and partially filled with
distilled water, a copper pipe and stainless steel pipe of same sizes.
1. Heat Pipe - Stainless steel pipe size 25 mm. dia. 300 mm. long, with both
side closed, evacuated and filled with distilled water along with fine stainless steel mesh inside the wall.
2. Copper pipe-25mm O.D. and 300 mm long..
3. Stainless steel pipe - 25 mm. O. D. and 300 mm long. All the pipes are positioned vertical with lower end heated by band heater and upper end surrounded by water. All the pipes are provided with five thermocouples along the length.
4. A common dimmer stat, 4 A capacity is provided to supply equal voltage to all the heaters.
5. Digital temperature indicator to measure temperature along the length of pipes.
6. A thermometer is provided to measure the temperatures of water in the tank.
HEAT TRANSFER THROUGH LAGGED PIPE:
SPECIFICATION:
The apparatus consists of three concentric pipes, at the axis of which a cartridge
heater is positioned. Two types of lagging materials are filled up, one between
innermost and middle pipe and other between middle and outermost pipe.
Temperature across the lagging material i.e. temperature of pipe walls for radial
outward heat flow are measured by the thermocouples. The heater can be
supplied with different heat inputs with the help of dimmer stat so that
characteristics of lagged pipe can be studied at different heat flow rates.
1. Pipes – a) Inner pipe 50mm. NB. 1000mm long G.I. pipe.
b) Middle pipe 100mm. NB, 1000mm long G.I. pipe.
c) Outer pipe 150mm NB.1000mm long G.I. pipe.
A cartridge heater is provided at axis of pipes.
2. Lagging a) Asbestos powder filled between inner and middle pipes..
b) Saw dust filled between outer and middle pipes.
3. Thermocouples with digital temperature indicator to measure the various temperatures.
NATURAL CONVECTION APPARATUS:
SPECIFICATION:
The ‘DYNAMIC’ unit consists of a vertical brass pipe heated by a cartridge
heater inside. The pipe looses heat to atmosphere by natural convection. It
is fitted in an enclosure to provide undisturbed natural convection currents.
Thermocouples are attached on the pipe to measure local temperatures.
Heater input is measured on voltmeter and ammeter. Thus students can
determine overall heat transfer coefficient and local heat transfer coefficients
in natural convection at various heat transfer rates.
1.2Pipe - Brass pipe, 38 mm. dia. (OD), 500 mm. long, fitted with cartridge
heater inside.
2) Thermocouples are fitted along the length of pipe for temperature measurement- 7nos.
3) Enclosure 200 mm. x 200 mm. x 800mm. size, with one side of perspex sheet.
4) Measurements & Controls
a) A dimmer stat for heater input control.
b) Voltmeter and Ammeter for heater input measurement.
c) Multi channel digital temperature indicator.
PIN FIN APPARATUS:
SPECIFICATION:
The apparatus consists of a pin type fin heated by a band heater at one end.
A centrifugal blower draws air over the fin. Thermocouples are attached
along the length of fin to note down the longitudinal temperature gradient.
Heat input to the fin is measured from electrical input to the fin. Air flow
is measured by an orifice and water manometer. Thus the students can
conduct the experiments in natural and forced convection and at various
airflow rates, various heat inputs and with fins of different materials
1. Fins -12 mm. OD.100mm long, with 5 thermocouples along the length,
one each fin made brass, aluminium & steel (m.s.)
2) Heater - Band heater to heat one end of fin.
3) Air flow duct-100 mm x 150 mm, 1 mtr. Long, connected at suction
of blower, with bell mouth entry.
4) Centrifugal blower of suitable capacity provided with orifice and water
manometer flow control valve on discharge side.
5) Instruments panel consisting of -
a) Ammeter and Voltmeter for heater input
Measurement.
b) Dimmer stat to control heat input to heater.
c) Digital temperature indicator.
STEFAN BOLTZMANN APPARATUS:
SPECIFICATION:
The Stefan Boltzmann constant is an important constant in heat transfer. The
apparatus determines Stefan Boltzmann constant. The apparatus consists of a
hemisphere surrounded by hot water. Hot water is obtained from a water-
heating tank. When the blackened disc is inserted at the center of hemisphere,
heat is transferred to the disc from hemisphere by radiation and its temperature
begins to rise, and from temperature rise rate. (It is measured at the intervals
of 5 sec.) Stefan Boltzmann constant is determined.
1) Water heating tank provided with electric immersion heater.
2) Hemisphere made of copper sheet, 200mm. dia. surrounded by
water jacket of 250mm. dia.
3) Test disc made of copper 20mm. dia. provided with thermocouple at
the center.
4) Multi channel digital temperature indicator 0-200 0C with 0.1 0C least
count to measure the temperature of hemisphere and disc.
5) Audible buzzer with timer to ring at every 5 seconds.
. THERMAL CONDUCTIVITY OF INSULATING POWDER:
SPECIFICATION:
The apparatus consists of a copper sphere in which a mica heater is fitted. The
sphere is surrounded by another bigger sphere and between the two spheres, the
test insulating powder is filled. Heat of the heater radically flows outwards in
all directions through powder. The temperatures of spheres i.e. temperatures
across the powder are measured. By knowing the input to the heater
conductivity of the powder can be determined.
1)Inner sphere - Copper sphere, 100 mm dia, halved construction with mica
heater inside.
3) Thermocouples on outer surface of inner sphere and inner surface of outer sphere.
4) Dimmer - 2 amps. Capacity to control input to heater.
5) A voltmeter and Ammeter to measure input to heater.
6) Multi channel digital temperature indicator to measure temperatures at various points
THERMAL CONDUCTIVITY OF METAL ROD:
SPECIFICATION:
The apparatus consists of a copper bar, which is heated at one end, a heat
sink is provided at other end. The test section of bar is properly insulated
& thermocouples are attached to observe the temperature gradient along
the length of bar. Heat conducted through the section of bar is measured
by heat collection in water cooled heat sink. A panel comprising of
controls and measurement is provided, which provides easy operation
and sturdy mounting of unit. Bar of different metal other then copper can
be provided, on request at extra cost.
1. Metal Bar-25 mm., of adequate length, provided with 8 thermocouples along the length, Band heater at one end and water cooled heat sink at other end. Test length of bar is adequately insulated.
