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1.Introduction of reverse circulation drilling
Reverse circulation drilling,referred to as "centre sample Recovery" or "Dual wall drilling",employs a dual wall pipe where the drilling medium,normally high pressure air,is passed between the outer and inner tubes down to the face of the drilling bit where it is returned up the centre tube along with the sample cut by the drill bit.
2.The use and the advantages of the reverse circulation DTH Hammer:
The reverse circulation system collects sample through the recovery holes in the face of the drill bit immediately as the cuttings or sample is formed.The drilled sample does not have to travel the length of the hammer where contamination and loss of sample takes place.
In broken and fractured ground conditions,the reverse circulation will often out perform the conventional hammer in terms of penetration rates.
Even in certain water bearing stratas it is still possible to collect a dry sample because the cuttings(sample)are collected as they are formed through the face of the drill bit.
4)Higher sample recovery
Because the sample is collected through the face of the drill bit there is no loss of sample when drilling through broken or fractured ground. And since the bit matched to the chuck size,there is very little bypass of sample and recovery rates o, up to 98% are generally achievable.
|Length(less bit)||weight(less bit)||external diameter||Bit shank||Hole range||Connection thread|
|Working pressure||Impact rate at 2.4Mpa||Recommended rotation speed||Air consumption|
We have delivered to Australia,Brazil etc.If you have any demands ,please kindly contact us immediately!
Contact Person: Mrs. Cathy Yuan
Tel: 0086 159 6388 1160