1.
INTRODUCTION TO PROJECT
This test
method covers the determination of the performance of commercial sizes of block
forms of thermal insulating materials when exposed to simulated hot surface
application conditions. The terms “hot-surface performance” has reference to a
simulated use-temperature test in which the heated testing surface is in a
horizontal position.
This test method refers primarily to high-temperature insulations that
are applicable to hot side temperature in excess of 200 0F (930C).
It may be used for materials such as performed insulations, insulating cement,
blankets, etc. by proper laboratory preparation of the sample.
This standard
does not purport to address all of the safety concerns, if any, associated with
its use. It is the responsibility of the user of this standard to establish
appropriate safety and health practices and determine the applicability of
regulatory limitations prior to use.
CHAPTER 2: COMPONENTS AND METHODOLOGY
2.1 COMPONENTS
v Heating plate (S.S Plate)
v Wood (Insulation material)
v 2 Electrical heater
(Strip type)
v Cover box (M.S. plate)
v PID Temperature controller
v Contactor
v 3
PIN Plug(6 amp,240 V)
v K
type Thermocouple
v Wire
(16 gauge)
v Bolt
and Miscellaneous
CHAPTER 3: SIGNIFICANCE & USE OF TESTING OF THERMAL INSULATION
Performance in
service is the final measure of value for a thermal insulation, but simulative
service tests may give useful indications. One type involves applications for a
specified time to a surface heated at a temperature approximately that of
intended service and noting during the test and afterward, changes in the
material and its properties. Measurements of these changes may be used for
predicting what may occur in service as a result of exposure to temperature
corresponding to those of the tests.
This apparatus
include a full complement of temperature sensor, a monitoring and control
system, and tools and fixtures that enable rapid and reliable installation and
removal of specimens.
The best use
of this apparatus can be visualized in terms of its ease in handling and
simplicity in design. Its best overwhelming use is its application in the
performance of high temperature thermal insulation. This apparatus works on
high temperature up to 800 0C on the safe side. The working
temperature is variable, so that we can test the specimen at the temperature as
per our requirements.
CHAPTER 4: EXPERIMENTATION PROCEDURE
Procedure of carrying out
experimentation for finding change in properties of insulation when exposed to
high temperature for long duration as per ASTM is given below.
1.
Use the
heating plate for testing the flat or block form of insulation. Use the heating
pipe for pipe insulation. The thickness of the layers in multi-layer insulation
and the total thickness of insulation applied to the hot surface for a test
shall be that recommended by the manufacturer for the temperature of the hot
surface in question, or as agreed between the manufacturer and the purchaser.
When multi-layer applications are to be tested, stagger each joint between
adjacent tests in the same layer with respect to the joint in the next layer.
Equally dispose about that joint the test piece in the next layer that covers
the joint of the preceding layer.
2.
Assembly of specimen on heating plate:
specimen for testing on a heating plate shall be 457.2 by 612.38 mm with
thickness 4 mm. Check each block for flatness and measure and record any
initial warp age. Cover the test area of the heating plate with the test
blocks. If any blocks have initial warp age, place the concave face toward the
hot side. Apply additional layers to the first layers when necessary to give
the total required thickness.
3.
Start the test
with the heating surface (plate or pipe) at room temperature. Employ a heating
rate consistent with the use for which the material is intended. During the
heating period, make qualitative observation to detect visible evidence of
flaming, glowing, soldering and smoking. After the hot surface has reached the
desired test temperature, begin a period of exposure of 96h. At the completion
of the test period, turn off the source of heat and allow the assembly to cool
to about room temperature before any specimens are removed.
NOTE: Ambient conditions on the exposed surface of the
test insulation shall be at room temperature.
4.
After test,
examine the specimens very carefully to detect any tendency toward cracking.
Note the number of cracks and the extent or the depth of cracking. Also note
any tendency toward de-lamination. Record other discernible changes, such as
evidence of flaming, glowing, soldering or smoking that can be observed by
visual inspection. In addition, measure the block or pipe specimen for warp age
by placing a straightedge along the length of the block or pipe and measuring
the maximum warp age at the center of the specimen with a steel rule.
CHAPTER 5: DESIGN
5.1
DESCRIPTION:
v HEATNG PLATE: It consist of corrosion resistant and heat resistant
plate .Plate is surface area 260 x 210 mm and 4mm thickness. Plate made of
stainless steel (s.s.).
v COVER BOX: it box made of mild steel(m.s.).dimension of box
61.38 x458.2 mm and 14.01 cm height and thickness 0.10mm.cover box in mounted
stand and made of material mild steel(m.s).at dimensions for 620.1x505 mm and
45mm height. Stand on mounted five strip
type plate heater.
v PID TEMPERATURE CONTROLLER:
Two main circuits are required. One is to make to average temperature of all
five temperature measured by the thermocouples. And second one is to require to
cut in/cut out the heater automatically at the selected temperature. The range
of PID temperature controller is 0-400̊ c measure.
v HEATER: It used heating the plate at set of temperature. Strip type heater and
made of material used stainless steel (s.s). Heating plate Voltage 120V
.capacity of heater Max sheath Temp. 1200̊ C.
v INSULATING MATERIAL: It set on the heating plate. e.g. (ceramic wool). Wood.
Ø High quality of tensile strength.
Ø high quality of stability and thermal and thermal
shock resistance , sound absorbability
v CONTACTOR: A contactor is a relay that is used for
switching power. They usually handle very heavy loads like an electric motor,
lighting and heating equipment. It is to require to cut in/cut out the heater
automatically at the selected temperature. Capacity of contactor rating AC – 3
phase and 25 amp, 11kw and coil voltage 220v AC.
K-type thermocouple:
Immersion probe type K (Cr-Al) thermocouple sensor, having handle 12 inch long,
'Inconel 600' sheathing of 6 mm diameter and 1 meter long 14x36 PVC
compensating cable.
Temperature Measurement:
Thermocouples shall be used to measure the surface
temperature of the heating plate and the heating pipe. They shall be applied
either by peening the individual wires into small holes drilled into the
surface and separated by not more than 3 mm or by joining the wires with a
welded bead and cementing them in grooves with the bead tangent to the surface
But not
projecting above it. Thermocouples wires are coated by the bids of ceramic
which enable them to withstand high very high temperatures up to 1200˚C
avoiding its ill effects like decomposition, corrosion, disintegration etc. the
combination of the thermocouple and measuring instrument used shall ensure an
accuracy of the temperature measurement of ±1%.
Type K is
general purpose thermocouple is shown in figure 3.4. It is low cost and owing
to its popularity, it is available in a wide verity of probes. Thermocouples
are available in the -200˚C to +1200˚C range. Sensitivity is approximate
41µV/˚C.
5.2
DIMENSIONS (all dimensions
are in mm.)
CHAPTER 7 : RESULTS AND DISCUSSIONS
Reporting of
the Insulating material as per ASMT should be done in following format with
required information. This in turn gives information of testing parameters to
be checked while carrying out testing work. Based on this testing parameters
one can state behavior of thermal insulation under high temperature and quality
of insulation.
·
Name and any
other identification of the material.
·
Kind of
insulation tested, sectional, segmental, or block.
·
Number of
layers of insulation applied.
·
Size and
thickness of each layer.
·
Temperature of
test.
·
Warpage.
·
Extent of
cracking.
·
Amount of
de-lamination.
·
Decrease in
thickness along the top of the pipe.
·
Other visible
changes.
·
Any evidence
of flaming, glowing, soldering and smoking.
We can also determine the thermal conductivity of the insulating material:
“The thermal conductivity is a rate of heat flow
across a unit area of a conductor per unit temperature gradient.”
Where,
K = Thermal conductivity,
w/m.k
Q = Rate of heat flow, k
A = cross Area of
insulation material, m2
dt = Temperature difference
between room temperature & plate temperature.
dx = Thickness of insulating material.
CHAPTER 8: READINGS OF TIME V/S
TEMPERATURE WITHOUT INSULATION
We
tested our apparatus first without thermal insulation and we set a temperature
of controller 150 C as in starting mode the current was flowing and the supply
is on so the temperature was also increasing .As the temperature reached on 152
C the contactor break the supply and hence current flow is stopped still
temperature of the plate increasing it reached up to 180 C and then again start
to decrease and when it reached to 148 C the contactor again give the supply
and hence the current start flowing still temperature decreases to 142 C and
again start increasing as this time it reached to 152 C supply again breaks
still temperature reach up to 175 c and then start decreasing as it reached 148
C current start flowing again but it decreased up to 143 C and again start
increasing as it reached 152 supply breaks but still it increased up to 170 and
then falling down temperature to 142 and then again it raises up to 175 C .so
thus this types of reading we were getting of testing without thermal
insulation.
|
Time (sec)
|
Temperature
|
Time (sec)
|
Temperature
|
|
0
|
80
|
150
|
140
|
|
5
|
81
|
155
|
144
|
|
10
|
83
|
160
|
145
|
|
15
|
84
|
165
|
147
|
|
20
|
86
|
170
|
148
|
|
25
|
87
|
175
|
150
|
|
30
|
90
|
180
|
152
|
|
35
|
91
|
185
|
154
|
|
40
|
93
|
190
|
158
|
|
45
|
95
|
195
|
160
|
|
50
|
97
|
200
|
162
|
|
55
|
98
|
205
|
166
|
|
60
|
100
|
210
|
163
|
|
65
|
102
|
215
|
168
|
|
70
|
104
|
220
|
152
|
|
75
|
106
|
225
|
146
|
|
80
|
108
|
230
|
144
|
|
85
|
110
|
235
|
134
|
|
90
|
112
|
240
|
142
|
|
95
|
115
|
245
|
143
|
|
100
|
117
|
250
|
145
|
|
105
|
119
|
255
|
148
|
|
110
|
122
|
260
|
150
|
|
115
|
124
|
265
|
153
|
|
120
|
127
|
270
|
156
|
|
125
|
129
|
275
|
158
|
|
130
|
132
|
280
|
160
|
|
135
|
133
|
285
|
162
|
|
140
|
136
|
290
|
164
|
|
145
|
134
|
295
|
69
|
|
150
|
140
|
300
|
68
|
CHAPTER 9: READINGS OF TIME V/S
TEMPERATURE WITH THERMAL INSULATION
Now
with thermal insulation material properly put on the plate and we again started
testing as before, we set the temperature of the controller again at 150 C. but
this time the controller also break the supply at 152 C but the temperature
keep increasing up to 236 C then it started to decreasing and as it reached to
148 supply again started but it reached to 140 C on lower limit of temperature
then it started to increasing and as it reached to 152 C the supply again broke
but temperature this time reached up to 172 C and then it started to falling
down as it reached to 148 C the supply
started and it went down to 143 C this time and again started increasing again
it broke the supply at 152 C but it reached to 172 C then it fell down again
then we got similar type of the observation 2-3 times so can say the cycle was
repeating it selves then.
|
Time (sec)
|
Temperature
|
Time (sec)
|
Temperature
|
|
0
|
48
|
150
|
70
|
|
5
|
48
|
155
|
71
|
|
10
|
49
|
160
|
72
|
|
15
|
50
|
165
|
72
|
|
20
|
50
|
170
|
73
|
|
25
|
50
|
175
|
74
|
|
30
|
51
|
180
|
74
|
|
35
|
52
|
185
|
75
|
|
40
|
52
|
190
|
76
|
|
45
|
53
|
195
|
77
|
|
50
|
53
|
200
|
78
|
|
55
|
54
|
205
|
74
|
|
60
|
55
|
210
|
78
|
|
65
|
55
|
215
|
77
|
|
70
|
56
|
220
|
77
|
|
75
|
57
|
225
|
77
|
|
80
|
58
|
230
|
76
|
|
85
|
59
|
235
|
77
|
|
90
|
59
|
240
|
74
|
|
95
|
60
|
245
|
73
|
|
100
|
61
|
250
|
73
|
|
105
|
62
|
255
|
73
|
|
110
|
63
|
260
|
73
|
|
115
|
64
|
265
|
72
|
|
120
|
65
|
270
|
71
|
|
125
|
66
|
275
|
71
|
|
130
|
67
|
280
|
70
|
|
135
|
67
|
285
|
70
|
|
140
|
68
|
290
|
70
|
|
145
|
69
|
295
|
69
|
|
150
|
70
|
300
|
68
|
CHAPTER
10: FUTURE SCOPE
- This test method covers the determination of the
performance of commercial sizes of both block and pipe forms of thermal
insulating materials when exposed to simulated hot-surface application
conditions. The term “hot-surface performance” has reference to a
simulated use-temperature test in which the heated testing surface is in a
horizontal position.
- This test method refers primarily to high-temperature
insulations that are applicable to hot-side temperatures in excess of
200°F (93°C). It is used for materials such as preformed insulations,
insulating cements, blankets, and the like, by proper laboratory
preparation of the samples.
- The values stated in inch-pound units are to be
regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not
considered standard.
- This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health
practices and determine the applicability of regulatory limitations prior
to use.
