S-08

Keywords

Y3

equipment or facility

Z4electricity

E25

general-purpose machinery
Kawasaki Heavy Industries, Ltd.

Top-Pressure Recovery Turbine Plant (TRT)
Features

Septum valve

TRT

Energy-saving equipment used for a blast furnace of a steel plant.
Power-generating equipment furnished with a function tocontrol the top pressure of a blast furnace.
Power is generated by driving a turbine using blast furnacegas generated in a blast furnace.
No fuel is needed for power generation.
Power generation + Top-pressure control
Top-pressure control
No fuel is burned; hence, no CO2 or other greenhousegases are generated.
Contributes to CO2 reduction in accordance with the power Energy ofEnergy ofNoiseblastgeneration volume.
BF gasVibration
Powerfurnace gaspressure
Generates less noise in comparison with a conventional
Wearpressure
septum valve, contributing to the improvement of theenvironment around a blast furnace.
No sophisticated technology is needed for operation and maintenance, which can easily be performed by blast
furnace operators and maintenance personnel.
Only small amounts of water, nitrogen, etc. are required for operation, which can easily be covered by existing
equipment for a blast furnace.

Basic Concept or Summary
A top-pressure recovery turbine plant is installed in the downstream of gas-cleaning equipment for a blast furnace.
There are two types of gas-cleaning equipment: a wet type that uses water and a dry type that does not use water.
After dust is collected by either of them, blast furnace gas is led to the turbine and drives it while expanding fromaround the furnace top pressure to atmospheric pressure. The power generated by the turbine is transferred to thegenerator and converted to electric power. In conventional practice, the energy of blast furnace gas was wasted bypressure reduction at a septum valve. It is now recovered as electric power, realizing significant energy saving.
SV

BF

BVDC VSDC

BF

SV

VS

BF

DCVS

BDC
TRT

TRT

(a) Wet-type top-pressure recovery turbine plant (b) Wet-type top-pressure recovery turbine plant

TRT

BF : Blast furnace
TRT : Top-pressure recovery turbine
BDC : Blast furnace gas dry cleaning equipment(dry-type gas-cleaning equipment)
VS : Venturi scrubber(Wet-type gas-cleaning equipment)DC : Dust catcher
SV : Septum valve
BV : Bypass valve(c) Dry-type top-pressure recovery turbine plant

There are two types of turbines: radial and axial turbines. Currently, axial turbines are widely used because they are
more appropriate for dealing with a large flow volume.
1st stage stator blades driving mechanism
Gas flow

Drain Nitrogen
Returned
Oil

Drain
Nitrogen

Drain

Axial turbine

1st stage stator blades driving mechanism

The top pressure is controlled by opening or closing the 1st stage stator blades of the turbine in accordance with the increase or
decrease of the blast furnace gas volume. With a conventional turbine, a governor valve was also used in combination forcontrolling the top pressure. A governor valve, however, induces a larger pressure loss in comparison with stator blades and thus
was disadvantageous in view of power recovery and noise prevention. Hence, in the system widely used now, the governor
valve is eliminated and the top pressure is controlled only by the 1st stage stator blades.

Governor valve

Stator bladesLowvelocity

Pressure

Pressure loss = Large

Turbulence

Larger output decrease Pressure loss = SmallPressure

Highvelocity

Velocity

Smaller output decreaseEffects or Remarks

S-08

Generally, electric power up to 35,000kW can be supplied depending on the size of the blast furnace. In
recent years, the size of the blast furnace has been increasing. As a result, the volume of power
generated by a top-pressure recovery turbine plant is increasing.
In September 1974, we delivered the first top-pressure recovery turbine plant in Japan, Since then, wehave continued various technological improvements for realizing better top-pressure control and higher
energy recovery such as the development of an axial-flow reaction turbine and the adoption of a control
system where only the 1st stage stator blades are used.
Year

Rated output (MW)40
Dry-type top-pressure recovery turbine
Wet-type top-pressure recovery turbine

30

'70

Turbinetype

74:

Septum valve
76: Governor valve
81:

2,000

4,000

Approx. 110%90:

Approx. 145%

Dry-type axial turbine

Governor valve + Stator blades

Septum valve
Governorvalve

Approx. 10%
Approx. 35%

Approx. 5%

Approx. 105%

Stator blades

Governor valve

Governorvalve

6,000100%Governor valve + Stator blades

Septum valve

Furnace volume (m3)Wet-type axial turbine

83:

Septum valve0

Increase in energy
Energyrecovery rate recovery rate'00

100%

79:

100'9074: Wet-type radial turbine

Toppressure
control

20'80

Introduction of technology from SOFRAIR

Stator blades

Septum valve
Statorblades

Septum valve
Statorblades

Installation in Practice or Schedule
Domestic

To date, 26 units have been delivered in total, out of which 19 units were wet-type top-pressure
recovery turbine plants and 7 units were dry-type top-pressure recovery turbine plants.

Korea
3JapanChina
7Taiwan

26U.S.A
26Brazil4

Our company's delivery record: 48 units in total (as of the end of August 2023)

OverseasTo date, 22 units were exported in total,
out of which 18 units were wet-type
top-pressure recovery turbine plants and4 units were dry-type top-pressure
recovery turbine plants.
Top-pressure recovery turbine plant for
USIMINAS (Photo)Ipatinga, Minas Gerais, Brazil
No. 3 Blast Furnace: Volume 3,180 m3
Wet-type top-pressure recovery turbine plant
Rated output 18,800 kW
Started power generation on June 14,2003.

Contact:

Kawasaki Heavy Industries, Ltd.,
Section 1, Power Plant Sales Department
Marketing & Sales Division
Energy Solution & Marine Engineering Company
Tel: +81-3-3435-2267 Fax: +81-3-3435-6601
URL: http://global.kawasaki.com/en/energy/equipment/blast.html