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**Process computer system**

Increase production yield using the following functions.

- Production schedule guidance for series casting
- Torch cutting optimization function

- Automatic plant control makes possible the production of super quality products.
- Automatic set-up data (Mold width, mold level, secondary cooling water, slab cut length, etc.)

- Report of the quality data for each cut slab.
- Report of the engineering data collected from the casting operation.

Hitachi has abundant experience in computer control for hot rolling mills. Hitachi can supply a mathematical model control system and information control system based on experience.

The setup function for roughing mills minimizes the number of passes of reverse rolling and maximizes the rolling productivity considering the machanical and electrical capability of the mill. The width setup model reduces width deviation.

The setup function for finishing mills optimizes reduction schedules to achieve good profile and flatness. It gives good setup values for thickness, finishing temperature and profile & flatness control. The self-learning function of mathematical models helps achieve high accuracy setup control.

The coiling temperature control consist of cooling schedule calculation, temperature tracking and dynamic control. Thermal characteristics of steel are non linear nor a simple curve, but our tuning tool of thermal models draws model parameters and model tuning is easy.

Reheating furnace temperature control minimizes fuel consumption of reheating furnaces. Mathematical models of furnace use a linear programming method and calculate optimum heating temperature patterns.

Mill pacing control forecasts time schedules of roughing mills and finishing mills. This realizes maximum productivity.

Hot strip mill systems have many mathematical models and model tuning is very important for startup of a hot rolling plant. Hitachi has many model tuning tools using statistic analysis methods.

Hitachi has extensive experience in computer control for cold rolling mills. Hitachi can supply a mathematical model control system and information control system based the experience.

The setup function calculates an optimum reduction schedule. Motor power balance is the most important item to get maximum productivity and a good reduction schedule. The reduction schedule is automatically adjusted by self learning function to get better power balance. Adjustment of the reduction schedule is not necessary. This means a "maintenance free reduction schedule system".

When the head end of a coil is passing through the first stand, actual data, such as entry thickness, rolling force and delivery thickness of the first stand, are gathered. The dynamic setup calculates setup values of succeeding stands again, according to the results of the self-learning function. This function shortens the off-gauge length. The dynamic setup calculates AGC (Automatic Gauge Control) parameters periodically. This increases AGC accuracy.

Mill pacing controls forecast time schedules of the entry facility, rolling mill, and delivery facility. This optimizes entry facility (Pickling) speed and rolling speed and minimizes the number of times of acceleration and deceleration. This realizes maximum productivity and stable rolling.

Cold rolling mill systems have many mathematical models and model tuning is very important for startup of a hot rolling plant. Hitachi has many model tuning tools using statistic analysis methods.

Optimum production scheduling system provides maximum plant operation rate, minimum cost and shortest delivery time.

A high performance setup system (strip temperature control, coating weight control, alloy control, shape control, etc.)

Quality control by collected process data analysis system

Ensuring high quality, easy maitenance and expandability by autonomous decentralized system architecture.

The range of control by the Process computer system covers from coil entry conveyor to the delivery conveyor of the CGL.The purpose for installation of the Process computer system is mainly:

- To increase the productivity of CGL by using the setup system and plant diagnosis. The Process computer functions enable automatic setup according to the production specification. The Process computer function makes the plant operation and maintenance easier by the functions mentioned above.
- To increase the yield ratio by the setup, keeping missoperation and human mistake stable.
- To decrease missoperation and human mistakes by automatic operation, operater guidence and data checks.

The functional abilites of the Process computer for CGL are as follows :

- PDI management
- Material tracking set up
- Process data acquisition and accumulation
- Plant operation input
- Setup calculation function by mathematical model for annealing furnace
- Logging
- Human-machine interface
- Roll administration

- Continuous operating 24 hours a day, everyday
- Highly reliable design for 10 years of operation
- Support for both hardware and software in case of an error with strong RAS function (*1)

(*1)RAS : Reliability Availability Serviceability

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- Microsoft ® Windows NT ® is the product name of Microsoft Corporation of the USA in the USA and other countries.

**Basically following Hitachi's information control servers are available for process computer system.**

- RS90/200 Series
- HF-W Series