Description:
Prodemo has developed a range of Concentric Overburden Drilling Systems for the continuous casing of medium to large diameter holes-up to 378mm diameter. The equipment gives excellent performance for drilling through loose overburden materials down into solid bedrock. At the start of the drilling operation, the seat against the casing shoe, When drilling commences, the segments swing out to drill the hole to the PESired diameter. The machines can be withdrawn through the casing by rotating the system anti-clockwise against the solid base of the hole or up against the casing shoe.
Application Range:It is suitable for drilling water wells , geothermal wells , short mircopiles ,medium mini-type grouting hole of building , dam and harbour project .
1. When drilling starts , the reamer swings out and reams the pilot-hole wide enough for the casing tube to slide down behind the drill bit assembly
2. When the required depth is reached , rotation is reversed carefully, whereupon the reamer swings in , allowing the drill bit assembly to be pulled up through the casing.
3. Casing tubes that are to be left in the drill hole should be sealed at the bottom of the hole by means of cement grout or some other sealing agent.
4. Drilling continues to the desired depth in the bedrock using a conventional drilling.
Technical Data
| Overburden Drilling Systems-Concentric Casing |
| Technical Data |
| Casting Tube |
Reamed Hole Dia(mm) |
Casting Shoe Inner Dia |
DTH Hammer Type(E) |
Drill Pipe(mm) |
| Outer Dia(mm) |
Inner Dia(mm) |
| 168 |
148-156 |
185 |
140 |
HD55 QL50 |
89 |
| 178 |
158-166 |
195 |
150 |
HD55 QL50 |
89 |
| 183 |
163-171 |
193 |
154 |
HD55 QL50 |
89 |
| 194 |
174-182 |
211 |
166 |
HD65 QL60 |
114 |
| 219 |
199-207 |
237 |
193 |
HD65 QL60 |
114 |
| 245 |
225-233 |
260 |
210 |
HD85 QL80 |
114 |
| 273 |
253-257 |
308 |
241 |
HD85 QL80 |
114 |
| 325 |
305-309 |
378 |
281 |
SD10 NUMA100 |
114 |
Audited Supplier 
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