Applications

The IRIS Hot Metal Detector is used for the most difficult detections applications in hot strip and plate mills with descale water, lot of steam or mechanical obstruction, such as :

• Detection before crop shear,
• At the edgers for precise timing of automatic width control.
  

IRIS 111-09 – General Description

The IRIS (InfraRed Intelligent Sensor) is a precision hot metal detector specifically designed to meet the most challenging requirements in hot rolling mills.
Combining fiber optic technology with state-of-the-art electronics, the IRIS is the finest hot metal detector available today.
The IRIS is comprised of three major elements : a fiber optic system which detects light from the material, a stainless steel mechanical system which positions and protects the optical system in the line and an electronic Sensor Control Unit which reacts to the presence or absence of light in the optical system.

IRIS Optical System

The optical front end of the IRIS consists of a small diameter lens securely mounted to a locating spider. The efficient design of these components allows this assembly to fit inside a one inch diameter pipe, enabling the sensor to be positioned in tight spaces beneath the roll line.
The lens focuses infra-red light onto a fiber optic bundle which transmits the light energy to the electronics enclosure.

IRIS Electronics

The photo-detector is the latest in a new generation of diodes, incorporating great sensitivity and speed of response. The photo-detector senses the presence or absence of light in the fiber optic bundle in just a few microseconds.
The IRIS is easily configured to suit the customer's unique applications. DIP switches are provided to adjust the gain of the sensor and the switching threshold.
IRIS outputs are switched 'ON' or 'OFF' signaling the presence or absence of light, respectively. The turn-off time has a DIP switch configurable delay, permitting the sensor to ignore cold spots, or patches of scale, etc.

IRIS Mechanical System

Only the IRIS from DELTA comes complete with all the necessary hardware to mount and protect the unit in a rolling mill. All the basic mechanical components are made of stainless steel. The main mechanical component is a one inch stainless steel pipe, bent and cut to required dimensions.

The stainless pipe is held in place by a mounting block, which is typically attached to the roll table support structure. The mounting block is designed to allow both lateral and angular adjustment of the pipe, permitting accurate positioning of the nozzle just below pass line.

In a typical installation the lens housing is set about 200 mm (8") below pass line and aimed so that the optical axis intersects pass line at the centreline of the roll table. The lens assembly is affixed to one end of the stainless steel support pipe, and covered with armoured stainless steel housing.
A 'T' fitting is attached to the other end of the support pipe. Clean, dry service air (or nitrogen) is supplied to the 'T' fitting. Flow through the pipe and around the lens assembly is sufficient to keep the temperature of the lens assembly and the fibre optic bundle within specified limits.
The exit velocity of the air prevents scale, water and the like from entering the lens housing and fouling the lens. The exit air flow also serves to keep the optical path from the housing to the material clear.
The fibre optic bundle is attached to the lens assembly and passed through the support pipe and the 'T' to the electronics enclosure. In some applications, the electronics enclosure is actually attached to the end of the support pipe; in standard applications it may be located up to thirty cable feet (30') away from the optical front end.
Standard lengths available are 9 m (30’), 12 m (40’) and 15 m (50’).