Instruments and Solution for Iron & Steel Industry

Challenges in the iron & steel plant

To technology in iron & steel industry is continuously improved to obtain the best possible performance. The improved plant performance gives rise to the higher quality improvement and lower cost, and simultaneously environmental friendly plant operation.

The control systems and field instruments are working at the various processes of the iron and steel plant. The process of iron and steel plant is starting from Sinter plant, Coke oven etc, and the blast furnace, iron pre-treatment are following. The products are widely used at furnace control and utilities in important processes (such as continuous casting machine (CCM)) in down stream of iron / steel making process.

Improve combustion efficiency and product quality

The temperature of the hot blast used in blast furnace has been increasing every year and currently stands at around 1300°C. Under such circumstances efficient operation is achieved by such measures as increasing the calorie value of fuel gas and recovering waste heat from gas. To further improve combustion efficiency and save energy, measurement of the oxygen concentration in exhaust gases is required.

A furnaces for heating slabs needs to be operated under low-oxygen conditions at high temperatures of 1000°C and above to prevent oxidation of the steel. The measurement of oxygen concentration in the furnace is essential.

Why buy Yokogawa?

Blast furnace and it's peripherals such as hot stoves, PCI (Pulverized coal injection), TRT (Top pressure turbine), etc. is the most important area in steel factories where Yokogawa delivers best performance. We have much experience in the area of instrumentation of not only the area but also all iron and steel process. The reliable and high quality measurement & control with Yokogawa's field-proven sensors and controllers helps the process optimization, and efficient/ safe/ reliable plant operation at low cost, and supports to achieve the dual aims of quality production and environmental protection through the field proven technologies.

Furnace Body Cooling

Overview and Problems

• Drum pressure control and drum water level control
• Monitoring of circulation water flow
• Enlarge the maintenance period and save the maintenance cost

Solution

• Field proven silicon resonant sensor guarantees long term stability
  EJA: 0.1 % of URL 5 years
  EJX: 0.1 % of URL 10 years
  Under all conditions (temperature, static and over pressures)

Benefits

• Improvement of a maintenance period
• High stability and High reliability
• Reduction of a maintenance cost

Monitoring of Cooling Water

Overview and Problems

• Tuyere water leakage detection system (BF)
• Secondary cooling water flow control (CCM)
  -Intermittent control
  -Mist spray control

Solution

• Adhesion diagnosis function
  -Replaceable electrode structure
• High quality and High performance
  -Accuracy: ±0.35 % of Rate (V = 0.15 ~ 10m /sec)
  (0.2 % of Rate is available as an option)
  -Repeatability: ±0.1 % of Rate (V ≥ 1m /sec)
• High noise suppressor and Quick response

Benefits

• Informs the timing of the maintenance of the electrode
• Safety operation
• High-quality steel producing

Monitoring and Controlling of Steam Flow and Temperature

Overview and Problems

• Renewal demand for obsolete instruments <YS><DXA>
• Need centralized data monitoring <YS><DXA>

Solution

• Colour LCD display with a wide variety of screen including meter display <YS><DXA>
• Expanded network function <YS><DXA>
• Control output backup function <YS>
• Display and operation <DXA>
  -Custom display function
  -Display and prints report from a web browsing
  -Review historical data with calendar search function

Benefits

• Perform safe and stable control at low cost <YS>
• DCS backup application <YS>
• Less engineering for replacement <YS>
• Create more intuitive overview monitors by customized display <YS>

Zirconia Oxygen Analyzer

Overview and Problems

• Energy loss from air leak in sintering furnace
• Combustion control in coke oven, hot blast stove, blast furnace and heating furnace
• Prevent oxidation of the steel in heating furnace

Solution

• Air leakage detection
• Measuring and adjusting oxygen concentration in the exhaust gas
• Monitoring oxygen concentration in heating furnace

Benefits

• Save energy and improve the efficiency of sintering furnace maintaining high quality
• Improve combustion efficiency in coke oven, hot blast stove, blast furnace and heating furnace
• Maintain high enough temperature and prevent hazardous condition in blast furnace
• Maintain high product quality in heating furnace

Combustion Control

Overview and Problems

• Coke oven gas and blast furnace gas are utilized in various combustion process
• Continuous and stable measuring is difficult because of dust, tar, naphthalene and so on
• Pre-treatment to eliminate dust, tar and naphthalene is necessary

Solution

• Stable measurement by combined YOKOGAWA reliable products and technically effective burner design
• Sampling system matching process condition

Benefits

• Accurate calorie measurement improves the heating process efficiency
• Boost yield and maintain high quality

Process Gas Chromatograph

Overview and Problems

• Guidance of the total furnace operation
• Detect abnormal condition

Solution

• Analyze blast furnace top gas, coke oven gas and mixed gas composition

Benefits

• Improve the process efficiency and custody transfer

Inductive Conductivity Analyzer

Overview and Problems

• The pickling process removes the contaminants from the metal's surface by using acids without damaging the metal's surface

Solution

• The acid concentration is monitored and controlled to remove scale and oxide sufficiently

Benefits

• Maintain the customers' high product quality efficiently enough in the pickling process

   

Technologies Commit Users' Benefits

Our Goal

Our shared goal is customer satisfaction through operational excellence.
Yokogawa has brought true innovations to industry. We are committed to ensuring accuracy, reliability, and safety of your production system throughout your business life cycle. Our comprehensive solutions and expertise help you achieve more results with less total costs of ownership. Below key technologies shall aim for your operational excellence.

DPharp Silicone Resonant Sensor

DPharp Pressure Transmitters with digital silicon resonant sensor delivers the maximum benefits from the elasticity of the single crystal silicon material while enhancing sensitivity and repeatability. The properties of the resonators remain constant for a long team. This makes DPharp the ideal pressure sensor for harsh industrial automation environments. DPharp offers the highest stability, repeatability and reliability.

Dual Frequency Coil Excitation

Magnetic Flowmeters measure flow volume based on Faraday's law. The frequecy of excitation current given to coils affects in the measurement accuracy and response time.

Dual Frequency Coil Excitation is Yokogawa's original technology to ensure ± 0.35 % accurate measurement as well as 0.1 second fast response simultaneously. Our signal processing technique enables us to bring the benefits of an AC & DC magnetic flowmeter into a single magnetic flowmeter.

YS1000 Dual CPU

With dual-CPU construction, manual control capability and display continues even if an abnormality occurs on one of the CPUs. If controller self-diagnostics detects a control circuit failure, the controller can suspend analog/digital output, switch to manual mode and allow manual control by operator. 

Gas Calorimeter Key Technology

Burner Unit

The sample gas burns inside the burner unit and a thermocouple detects the burning temperature increase. The air is introduced from the air inlet and divided to the primary, secondary and tertiary air. The primary and secondary ones are for burning the sample gas and the tertiary is for diluting and stirring the exhaust gas. The sample gas is mixed with the primary air (In case of the low calorie gas, the primary air is throttled), and burnt completely by the secondary air. Then, the combustion temperature generates, and burnt gas is promptly diluted and stirred by the tertiary air. Finally the gas is exhausted out from the top of the detector.

The increased temperature is measured with the difference of the electromotive force between the cold junction point (located at the air inlet) and the hot junction point (inside the mixed diluted exhaust gas). The heating wire wound the burner tip is used for both ignition and preheating (In case of low calorie gas).