Delay Detonators

IDL manufactures Delay Detonators in three categories - Long Delay, Short Delay and Coal Delay (Permissible Electric Detonator). Long Delay and Short Delay Detonators consist of an aluminium tube filled with ASA and PETN as primary and secondary charges, while Coal Delay Detonators consist of a copper coated steel shell carrying similar charges. Judicious usage of delay detonators achieve good fragmentation with controlled throw enabling easy mechanical loading and providing greater control of vibration, noise and flyrock. They can be used in dry and wet conditions.

Long Delay Detonators have delay numbers ranging from zero to twelve (0 to 12) with a nominal time interval of 0.5 second between successive delay numbers. For identification of delay numbers it is ensured that all the detonators have delay number stamped on the bottom of the shell as well as marked on the tag attached to one of the legwires and colour coded for each delay number for easy identification.

Long Delay Detonators are designed for use in underground mining for driving shafts and tunnels, blasting raises and sinking shafts. In many cases they are used for stopeing in metal mines, trenching and other blasting applications. The longer delay period allows sufficient rock movement before firing the next shot.

Short Delay Detonators have delay numbers ranging from zero to twenty (0 to 20) with a nominal time interval of 25 milliseconds between successive delay numbers from 1 to 6, 50 milliseconds for 6 to 8, 75 milli seconds for 8 to 18 and 100 milliseconds for 18 to 20. Delay numbers 1 to 10 are identified with number stamped at bottom of the shells and by number tag on the legwire. Delay nos 11 to 20 are identified only by the number tag on the legwire and have no number stamped on the bottom of the shells. Lead wires of each delay no. are colour coded for easy identification. Electrical fuse heads are fitted to the filled shells. Precise consistency of the unique design of the fusehead is maintained by a fully automated proCess and strict quality control.

Short Delay Detonators are designed for use in opencast and underground metal mines, for driving tunnels, drifts and shaft sinking and in quarries where multishot rounds are required.

Coal Delay Detonators are non-incendive in nature and have delay numbers ranging from zero to six (0 to 6) with a nominal time interval of 25 milliseconds between each successive delay number. The delay numbers are stamped on the bottom of the shell and also displayed on tags on the legwire. Lead wires are colour coded for each delay no. for easy identification. Electrical fuseheads are fitted to the filled shells. Precise consistency of the fusehead is maintained bya fully automated proCess. With coal delay detonators, all the ShotS can be connected in one series and fired in one round with a desired del

Coal Delay Detonator has the approval of Director General Mines Safety for use in Degree I/II/III gassy mines/seams. They can be used for all types of blasting in underground gassy mines.

Packing

Each case contains Delay Detonators of the same number. 5 detonators are held in a bunch and 5 such bunches are banded to make a bundle of 25 noS keeping all detonators and shunted ends withi~ the bundle. TWO SUCh bundles of 25 noS each are wrapped in kraft paper making a packet. Depending on the length of legwire requisite number of packets are packed in. wooden cases lined inside with water-proof paper. Case marking provide for indiCating wire length, type of wire and delay number. External Case dimensions are 540 x 318 x 286 mm (V 01. 0.049 CBM)

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See Also:

Plain Detonators
Instantaneous Electric Detonators
Delay Detonators
Seismic Detonators