DETEC - Number One

Quality makes all the difference in harsh working environments such as mining and manufacturing where crushing, grinding, chipping and sawing equipment is in constant use. Only the best survive. The 'Detec' HFE Metal Detector has the highest quality levels and functional standard designs to provide long term, economical service.

Exceptional performance that can be relied upon day after day has built the 'Detec' reputation. Balanced circuit stability ensures years of trouble-free operation even in the most exposed working conditions of heat, dust, vibration and humidity.

Easy installation is a feature that sets the 'Detec' HFE metal detector apart. In very little time at all, the equipment is up and running at maximum efficiency.

Custom designs for individual needs is all part of the service. The skills and experience are available to design specialised equipment to satisfy your particular situation.

Operation

H.F.E. Type

The detection system is based on an oscillator powered by a constant current source and where the sensing coils are the inductive component of the oscillator circuit. The system is essentially designed to detect moving metal and is therefore not affected by stationary metal in close proximity to the sensing head. It is also able to ignore a constant mass of moving metal as in the case of a steel cord belt. However, it will detect a broken cord or a splice, hence the need for a belt clip nullifier on belts with mechanical splicing and/or steel cords. When metal is introduced into the field created by the sensing head coils, this causes a change of 'Q' of the oscillator circuit and because the oscillator is supplied from a constant current source, a voltage change occurs. This voltage is then amplified and used to trigger the various output circuits.

Magnetic Type

The magnetic detector radiates a magnetic field. Any magnetic metal tramp passing through the field cuts the flux and thereby generates a pulse which is monitored by the control circuitry. This results in a similar de-energisation of relay as described above and operation of warning red lamp, etc.

Model Selection Parameters (General)

HFE Standard Type

(i) Single Head

*Refer to sensitivity chart for correct selection. Select where burden depth is not greater than 300 mm and tramp size is quite large near the top of the burden.

(ii) Dual Head

*Refer to sensitivity chart for correct selection. Select where burden is deeper and a smaller tramp metal on top of burden is required to be detected. Each sensing head has an individual sensitivity control.

(iii) Magnetic Type

Select where only ferrous tramp materials are required to be detected. Refer to T.S.S. for further details regarding installation.

Dual & Single Head Detectors in Typical Applications

Standard Specifications

Control Box

Steel zinc metallised finish cabinet industrial protection Class IP55 with locking handle, (IP67 polycarbonate box with clear lid/IP66 steel, optional extra).

Control Equipment

An adjustable 10-step sensitivity control to meet the desired level of detection. Manual or auto reset facility. An instantaneous/delayed pulse tripping mechanism for the conveyor drive. (Built in circuit for field fitment of belt clip nullifier if later required).

Supply Voltage

Standard 240V 50/60 HZ or alternative 110V 50/60 HZ (Client to nominate).

The Single & Dual Head models of the popular DETEC Industrial Metal Detector are widely used throughout Mining, Quarrying, Brick & Tile and other Extractive Industries.

DIMENSIONS FOR STANDARD DETEC SINGLE & DUAL HEAD H.F.E. METAL DETECTORS

Plant Specifications (Information required for quotation)

1. Material conveyed
2. Belt type
3. Belt speed
4. Belt splice
5. Belt width "A"
6. Belt trough angle "B"
7. Maximum material depth (including lump)

Detection Requirements

(At maximum level setting)

Sensitivity

The degree or effect of tramp metal on this field is governed by:

(a) Proximity to the sensing head surface.
(b) Size and shape of the tramp metal.
(c) Electrical conductivity of the metal.

Adjustments to obtain the desired level of detection are firstly carried out by holding the metal objects by hand. Use rapid movements along the axis of the conveyor at three levels:

• Immediately above the belt surface.
• At approximately the centre of the burden height.
• At the estimated tip of the burden height.

If the detector at control setting '2' is over-sensitive to small items of tramp metal in position 1, lower the whole unit (and, hence, the sensing head) progressively in small increments until a reasonable balance is obtained between sensitivity and nuisance tripping.

Adjust sensitivity control to the required GO/NO-GO setting.

NOTE: False triggering will occur if there are any metal parts on the installation, within the range of the field, which can move in relation to the sensing head. It is important to ensure all fixing bolts on mounting frame and control enclosure are securely tightened.

DETEC Aperture Detectors for Special Occasions

Manufactured for the Timber Industry

Conveyor mounted aperture type complete with pneumatic system.

The aperture detector used to detect tramp metal present in materials being transported through the duct at high velocity. This application is particulary suited to spinning, carpet manufacture and allied industries

Other Options (on request)

Trip counter - Audible Alarm - Strobe Light.

Also additional contacts can be provided for controlling external equipment.

ANCILLARY EQUIPMENT FLAG MARKER

(mechanical marking system)

A solenoid operated steel disc (mechanical flag) marks the tramp material location in the conveyed material. An interlocking switch prohibits the restarting of conveyor until the flag is inserted back in the flag marker.

BELT CLIP NULLIFIER

(for use on steel cord belts or on belts with mechanical fasteners)

Operation - A plate fastener is fixed approx. 200mm ahead of metal splice. When the fastener passes over the nullifier detector head an alternate power supply is provided to the relay for a set period to maintain set while the splice passes over the sensing head. A time adjustment is provided in the control box to limit the time of this function and is adjusted relative to the belt speed.

DYE MARKER

(liquid marking system)

A stainless steel fabricated head containing solenoid pump switch gear and a PVC 5 -litre tank constitute the physical description of the dye marker. The solenoid pump provides a jet of liquid dye to locate the tramp metal when it is detected. A relay is provided to maintain solenoid action for any further tramp detected during conveyor slow down.