INDO THERM ENGINEERS PVT. LTD.
Unit-I : Plot No. A-374, Road No.9, Wagle Industrial Estate, Thane - 400 604.
Tel.: 022-41515454-68
Unit-II : B/23, Additional Ambernath, Anand Nagar, Ambernath (E), Dist. Thane.
Tel. 0251-6481682-89
E-MAIL : info@indothermindia.com / indotherm.amb@gmail.com
Procedure No. : P-0136/2024-25 R.01
Date : 20.01.2025
ITEM
: PLATES
CLIENT
: M/S. IMPLOCLAD TECHNOLOGIES PVT. LTD.
INSPECTION
: TPI / NPCIL
H.T. METHOD : MODULAR (GAS-FIRED) FURNACE METHOD
SITE
: OUR AMBERNATH WORKS
PROCEDURE FOR NORMALIZING OF PLATES
2.
1.
0
Rev.
20.01.24
09.01.24
Date
P-0136/2024-25 R.01
P-0136/2024-25
Description
SLK
SLK
Prepared By
Procedure Ref. No. P-0136/2024-25 Rev.01 dtd 20.01.2025
ARF
ARF
Checked
Approved
Page 1 of 4
PROCEDURE FOR NORMALIZING OF PLATES
BY MODULAR (GAS-FIRED) FURNACE METHOD
FOR M/S. IMPLOCLAD TECHNOLOGIES PVT. LTD.
I.
JOB DETAILS :
Item
:
Plates
Sr. No.
A
B
C
Length
3500
7000
5000
Width
3000
2000
3000
Inspection
Site
:
:
Thk
51
33
28
Qty
4
7
5
TPI / NPCIL
At our Ambernath works
II.
HEAT TREATMENT CYCLE :
Rate of heating
:
100ºC /hr (max) from 425ºC
Soaking temperature :
910 +/- 10ºC
Soaking time
:
1.2 min/mm (62 minutes) for Sr. No. “A” - Charge 1
1.2 min/mm (40 minutes) for Sr. No. “B” – Charge 2
1.2 min/mm (34 minutes) for Sr. No. “C” – Charge 3
Rate of cooling
:
Cooling in still air.
III.
FURNACE SPECIFICATION:
Furnace Type
Furnace Size (Inside)
Heating Method
No. of Burners
No. of Exhaust opening
No. of Control Zones
Furnace Insulation
IV.
:
:
:
:
:
:
:
Top Hat Type Modular (gas fired) Furnace
12M (L) x 5 M (W) x 5 M (H)
High Velocity (Gas Fired) Burners
Two nos. along with heat distribution pipes.
Two Nos.
Two Nos.
Five layers of ceramic fiber insulation having
125mm thk. 128 Kg.Cu. M. density shall be fixed
Along with SS wire netting roll and binding wire
on all the sides and sand up to 8”height shall be
placed on hearth.
HEAT TREATMENT BY MODULAR FURNACE METHOD:
The method consists of fabrication a furnace panel / case work using angles and
channels. The interior of the furnace case work will be lined with 125mm thick
ceramic fiber insulation of 128 kg/ cu.m. density and sand up to 8” height shall be
placed on the hearth of the furnace to prevent heat losses to the floor.
The gas-fired burner is designed in such a way that the primary flame envelope is
contained within a minimal distance of the burner exit nozzles, consequently flame
impingement is eliminated. The flame stability over the entire firing range has a
further advantage of 1:30 turn down ratio with excess air, with such positively induced
convective heat transfer by which close temperature uniformity with minimum
oxidation are achieved and also the flue to load temperature differentials are greatly
reduced.
Procedure Ref. No. P-0136/2024-25 Rev.01 dtd 20.01.2025
Page 2 of 4
This results in both fuel and time saving particularly heat treatment applications,
which demand a rapid turn around and at the same time, a close tolerance. The gasfired burner, which is portable, will be inserted into the furnace walls. The burners
are positioned in such a way, to ensure much better temperature distribution all
throughout the furnace.
In this case, furnace size shall be 12 m (L) x 5 m (W) x 5 m (H) and two nos. High
velocity burners shall be placed diagonally along with heat distribution pipes, as
shown in attached sketch.3A0136-R.01 (Page 1 – 3 of 3)
The plates shall be supported on the suitable fire brick supports placed in the furnace
in such a way that there shall be one over the other by maintaining a gap of 150 mm,
min. 0.5Mtr gap from all sides and min. 0.3Mtr gap above the hearth, to take care of
free expansion during the time of heat treatment. The moment soaking complete, the
furnace top hat and side panels shall be opened to cool the plates in still air.
V.
INSULATION:
The interior of the furnace case work will be lined with 125mm thick ceramic fiber
insulation of 128 kg/ cu.m. density.
The insulation material shall be fitted with SS wire netting roll and SS binding wire.
This backing will serve to reinforce insulation and assist in shortening the work
period involved for its application. On the hearth of the furnace sand up to 8” height
shall be placed to prevent heat losses to the floor.
VI.
CONTROL:
Gas train is incorporated by sophisticated automatic flame failure device, spark
ignition, pressure gauges with isolating device required for controlling the burner.
The high velocity combustion air fan completes the system.
The burner shall be controlled manually by continual inspection of the temperaturerecording instrument. Control of the burner shall be by manual adjustment of the gas
flow. The turn down ratio for the burner is high in the order of 1:30, which gives a
high degree of control at all stages of the firing. By this system, no local hot spots are
introduced and optimum temperature uniformity with minimum oxidation is achieved.
VII.
THERMOCOUPLE POSITION :
1.
The thermocouple shall be of the Nickel-Chromium/ Nickel-aluminum `K’ type of
21/22 SWG. These calibrated thermocouples shall be attached to the shell with the
help of thermocouple attachment unit (TAU).
2.
Total nos. thermocouples shall be attached at the locations indicated in the
appended drawing no. 3A0136-R.01, are as follows:
Page 1 of 3 = 08 Nos. (i.e. each 02 nos. thermocouples on each plates)
Page 2 of 3 = 21 Nos. (i.e. each 03 nos. thermocouples on each plates)
Page 3 of 3 = 15 Nos. (i.e. each 03 nos. thermocouples on each plates)
Procedure Ref. No. P-0136/2024-25 Rev.01 dtd 20.01.2025
Page 3 of 4
VIII. THERMOCOUPLE EXTENSION CABLE :
Thermocouple will be connected to the temperature recorder via color-coded copper
constant compensating lead of proper specification.
IX.
TEMPERATURE RECORDER:
Will be of potentiometric self-compensating Type `K’ duly Calibrated, the certificate
conforming the same shall be hand over to the concerned authority.
X.
POWER CONSUMPTION:
Connected load will be 45 HP at 440V, three phase control unit will be kept adjacent
to the job.
XI.
DOCUMENTATION:
One supervisor and three technicians will be deputed to laise with your concern
personnel to ensure that all procedural requirement shall fully complied with.
1.
2.
3.
4.
5.
Procedure details
This procedure booklet.
Calibration certificate of temperature recorder
Test certificate of thermocouple
Heat treatment specification and chart receipt form.
Temperature recorded chart duly signed by concern authority.
For INDO THERM ENGINEERS PVT. LTD.
A.R.FERNANDEZ / BECHAN R.BHAGAT
Director
Encl.: Sketch 3A0136-R.01 (page 1 – 3 of 3) showing Modular Furnace with the
thermocouple position.
Procedure Ref. No. P-0136/2024-25 Rev.01 dtd 20.01.2025
Page 4 of 4