THIS IS TWIN HEARTH FURNACE IS A RUSSIAN TECHNOLOGY FURNACE IN BHILAI STEEL PLANT.THIS PROCESS IS A CULTURAL PROCESS OF STEEL MAKING IN INDIA. BHILAI STEEL PLANT HAVE 4 TWIN HEARTH FURNACES.FIRST TWIN HEARTH FURNACE ESTABLISH IN BHILAI STEEL PLANT(BSP) IN 1986. THE BSP, INDIA'S FIRST AND MAIN PRODUCER OF STEEL RAILS,AND OTHER STEEL PRODUCTS.

1. PRESENTED BY
MUKESH KUMAR

3. FURNACE
 Russia designed , Twin Hearth Furnace are the modernized version of
the older Open hearth Furnace.
 The management of Bhilai Steel Plant, with a view to enhance steel
productivity as well as bringing down the cost of steel, thought of
changing Open hearth route to twin hearth.
 Route coupled with ingot casting way back in 1984. First twin
hearth furnace (THF-I) came into existence in 1986.
 Today shops has 4 Twin hearth Furnaces of which 3 furnaces are
operational at any movement and 1 furnace may under hot reserve or
refractory lining.
 Apart from higher productivity and lower operating costs, THFs have
got several other advantages as compared to OHFs. From operation
point of view.

4. :: PRINCIPLE ::
Twin hearth furnace is a double bath furnace without
regenerators; designed for operation with intensive
oxygen blowing into the bath.
:: EQUIPMENT DETAILS ::
Basically the entire operation in THFs is based on
getting the heat generated through the oxidation of
metalloids present in Hot metal.
Various elements of the furnace can be termed as
under:-

5. a) Lances
The furnaces are equipped with six double body multi-nozzle
copper tip lances, three for each hearth to inject oxygen into the
bath.
All the lances can be operated individually in upward or down
ward directions, as per the requirement from the control room.
b) Burners
The furnaces are equipped with four, double body burners, two
for each hearth to provide PCM as an external source of fuel as
and when required. (PCM : Pitch Cryosite Mixture) B1 and B3
are for right hearth where as B2 and B4 are for left hearth.
c) Atomizers
Atomizers are provided in the slag pocket of the furnace to
control the temperature of Waster gas. Atomizer is made of two
concentric pipes one each for water and compressed air. It has a
nozzle through which water and compressed air come out in
mist form. Each furnace is equipped with 8 atomizers, 4 in each
slag pocket.

6. COOLING SYSTEM OF THE FURNACE
Basically there are two types of cooling systems, which
are used in the furnace, namely Water cooling system
and Evaporative cooling system.
Water cooling system:-
The elements under water cooling system are cooled by virtue
of high pressure water which are facing high temperatures. The
elements like doors, double body lances, burners etc. are
maintained through Water cooling system.
Evaporative cooling system:-
The elements, which are very closely exposed to the bath, are
maintained with evaporative cooling system. The elements like
doorframes skew beams and screens are maintained under
evaporative cooling system.

7. Schematic :- diagram of a Twin hearth furnace

8. The equipments needed for running the furnace smoothly are
as listed below –
a) Charging Machine
b) Fettling Machine
c) Hot metal Crane
d) Teeming Crane
e) Launder
f) Chute
g) Bunker
h) Iron Ore Scoop
i) Cleaning Box
j) Billet Box
k) Slag Removal System
l) Gas Cleaning PlantZ

9. 1. First of all 50 tones scrap of is added in the bottom of
furnace.
2. 10 tones Limestone is added.
3. 200 tones of hot – metal is charged from charging side
through chute.
 Before hot metal charge analysis of hot metal :-
 C = 4.0 – 4.5 %
 Si = 0.6 – 1.0 %
 MN = 0.6 – 1.0 %
 S = 0.05 % max
 P = 0.10% max
4. Then oxygen blowing through lance .
a) Blowing is finished after 1Hr- 45min of blowing , with
1650O
C bath carbon below 0.10

10. What are the oxidation reactions?
The principle reactions in steelmaking comprise of
oxidation of impurity elements by oxygen dissolved
in hot metal or FeO content of slag.
[Fe] + [O] = (FeO)
[Mn] + [O] = (MnO)
[Si] + [O] = (SiO2)
[C] + [O] = (CO)
2[P] + 5[O] = (P2O5)

11. Note:-
• All reactions are exothermic.
• C is removed as gas.
• Except C, all other impurities are removed as oxides and all
these oxides float on the surface of the molten metal during
refining of hot metal to steel.
• Iron oxidation is unavoidable. Oxidation of Fe is loss in
productivity; hence its oxidation must be controlled.
• Oxygen must be dissolved to remove an impurity from the
hot metal.
We begin with considering oxidation of an individual
element and evolve the optimum conditions using
thermodynamic principles.

12. b) After taking sample and temperature, re – blowing is done for
chemistry and temperature.
c) Metal is tapped in the preheated by pit side.
d) During tapping when ladle is fill half the Ferro – Alloy is added
according to requirement with the help of crane.
5. Final Sample and temperature is taken.
6. Then steel is sent to next for teeming* into moulds.
*Teeming – teeming is process of filling ingot by liquid steel /
Ingot casting . The teeming ladle is equipped with
slide gate mechanism. The each ingot capacity is
9.1 & take time to filling is normally 50-60 sec
(In BSP).
7. The whole process take 5hr 10min tap to tap.

14. • Introduction of molten metal into a mould cavity
where cavity where the metal confirm to the shape
of the cavity.
• Solidification of liquid steel.
• Molten metal into metal cavity.
• Heat transfer during solidification and cooling of
the metal in the mould.
• Ingots are passed into ingot mould.
-- square, rectangular.
In BSP SMS – 1 ingot casting made BILLET which
made
- ROD, COIN , TMT BAR.

16.  ACCORDING TO Bishop dust loading in stack gases
from these furnace may go as less than Open Hearth
Furnace process.
 Report the average concentration for the entire heat to be
0.23gr.per standard cu.ft.
 A no. of 5 microns particles are burn by the e STACK
zone which is not many harmful for the environment.

17. • The Bhilai steel plant(BSP), India’s first and main producer
of steel Rails, as well as a major producer of wide steel plates
and others steel products.
• It was set up with the help of the USSR in 1955.
• The eleven- time winner of the Prime Minister’s Trophy for
the best integrated steel plant in the country, has been
India's sole producer of rails and heavy steel plants.
OUR TRAINING INCHARGE
SIR ROHIT SAM

18. ANY
QUESTION