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OFT-7 SERIES FURNACE VIEWING TELEVISION SYSTEMS

1. OFT-7 FURNACE VIEWING TELEVISION SYSTEM
2. OFT-7A and OFT-7A-DS FURNACE VIEWING TELEVISION SYSTEM
3. SPECIFICATION SHEET

1. OFT-7 FURNACE VIEWING TELEVISION SYSTEM

The OFT-7 system represents the current state of the art in furnace and boiler viewing television.

This system was designed for applications where water-cooling is not available, but very high temperature operation is required.

The principal features of the OFT -7 system are a very small overall diameter of only 35mm, and the provision of an automatic retraction system as standard.

As with all Industrial Television furnace viewing systems, the OFT -7 provides high-quality pictures by viewing the furnace interior directly with no windows to degrade the image or require cleaning. Cold clean air is passed over the optical surfaces of the system to keep them clean and provide secondary cooling; additional layers of cooled and ambient air provide primary cooling for operation at furnace temperatures up to 1600°C.

Because of the very arduous conditions when using air-only cooling at these temperatures, the system incorporates an automatic retraction system as standard to withdraw the assembly from the hot area in the event of any loss of cooling air, power, or in the event of temperature excursion outside defined limits.

The system is designed so that in the event of alarm activation it latches out and requires manual reinsertion into the hot zone; this ensures that the source of any alarm condition must be investigated, prohibiting the overriding of the system by the operator following a transient alarm. It is possible at specific user request to provide remote re-insertion, after the alarm condition has cleared, but we do not recommend this, as the cause of the alarm should always be investigated at the camera location.

The system is fail-safe and will still retract even in the event of total failure of all services.

High-efficiency filters are provided to allow operation from normal plant air, and it is possible to change these on-line without withdrawing the camera from the furnace, so the pictures are not lost to the operator, even

All hardware required for a complete operating system is included and no further items are required apart from air and electrical services, and cabling between the furnace and operator's location.

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2. OFT-7A and OFT-7A-DS* FURNACE VIEWING TELEVISION SYSTEMS

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The OFT-7 series systems represent the current state of the art in furnace viewing television technology; the -7A versions being designed specifically for the aluminium industry.

This system was designed for applications where watercooling is not appropriate, but very high temperature operation is required.

The principal features of the OFT-7 systems are a very small overall diameter of only 35mm, and the provision of an automatic retraction system as standard.

A unique feature of the type OFT-7A-DS* is the incorporation of two cameras operating in different parts of the spectrum. A colour camera provides a picture of what an operator would see by looking into the furnace, whilst the second camera operates in the infra-red part of the spectrum to provide additional thermal information and also enhanced visibility at low temperatures and under conditions of fume in the furnace atmosphere.
This allows the OFT-7A-DS* system to provide pictures over a wider range of in-furnace conditions than would otherwise be possible with a single-sensor system

As with all Industrial Television furnace viewing systems, the OFT-7 provides high-quality pictures by viewing the furnace interior directly with no windows to degrade the image or require cleaning. Cold clean air is passed over the optical surfaces of the system to keep them clean and provide primary cooling; additional layers of cooled and ambient air provide secondary cooling for operation at furnace temperatures up to 1600oC.

Because of the very arduous conditions when using air-only cooling at these temperatures, the system incorporates an automatic retraction system as standard to withdraw the assembly from the hot area in the event of any loss of cooling air, power, or in the event of temperature excursion outside defined limits.

The system is designed so that in the event of alarm activation it latches out and requires manual reinsertion into the hot zone; this ensures that the source of any alarm condition must be investigated, prohibiting the overriding of the system by the operator following a transient alarm. It is possible at specific user request to provide remote re-insertion, after the alarm condition has cleared, but we do not recommend this, as the cause of the alarm should always be investigated at the camera location.

The system is fail-safe and will still retract even in the event of total failure of all services.

High-efficiency filters are provided to allow operation from normal plant air, and it is possible to change these on-line without withdrawing the camera from the furnace, so the pictures are not lost to the operator, even momentarily.

All hardware required for a complete operating system is included and no further items are required apart from air and electrical services, and cabling between the furnace and operator's location.


* Patent applied for

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TYPE OFT-7, -7A and -7A-DS FURNACE VIEWING TELEVISION SYSTEMS

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Specifications:
Camera: Colour solid-state unit with CCD sensor
  PAL/NTSC format as appropriate
-DS model: As OFT-7 but with additional solid-state monochrome sensor operating at 1000 or 1100nm wavelength with narrow-pass filter
Lens: Special optical system with field of view to suit application (maximum 900)
In OFT-7-DS system special optics allow both cameras to view through the same lens assembly
Housing: Stainless-steel multi-layer air cooled.
Length to suit furnace wall and refractory thickness, typically 800mm
Diameter of through-wall optical assembly: 35 mm
Automatic retraction system in event of alarm activation withdraws assembly from hot zone for safety. Local isolation of auto-retract action is provided for safety of service personnel.
Junction Box: Size 800mm (h) x 600mm (w) x 250mm (d)
Houses all electrics, pneumatics and alarm relays.
Monitor: (Standard) 36cm (14") picture tube metal-cased industrial unit (with dual inputs for -DS version)
Size 340mm (h) x 346mm (w) x 414mm (d). Weight 15Kg (Other sizes are available)
An additional monochrome monitor can be provided if both pictures require viewing at the same time
Services:  
Air: Total flow <650 litres (25ft3)/min free air at inlet pressure of 4-7 bar (60-100 psig)
Primary (cooled) air flow is approximately 180 litres (6.5ft3)/min
Secondary air volume will depend on furnace temperature.
Filters are supplied to ensure suitable air quality when fed from plant air supply.
Electrical:  
Junction Box: 90-260V AC, 47-63Hz
Monitor(s): 100-240V, 50-60Hz
Approximately 95 watts
Cabling: A 75 ohm coaxial cable (two for -DS system) is required between junction box and monitor locations; alarms will depend on local requirements, but for full duplication at remote point a 6 core cable is required.

There is no practical limit on the distance between camera and monitor, but if this is very large (above 400 metres) additional equipment is required to process and amplify the signal.
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Due to our policy of continual product development, specification may change without notice.
All Industrial Television and Optics products are designed and built in Britain.