• Model NO.：Drilling Bits
• Color：Requirement
• Size：12", Customized
• Machine Type：Drilling Equipment
• Application：Mining
• Advantage：High Wear Resistant
• Weight：140 Kg
• Warranty：1 Year
• MOQ：5 PCS
• Transport Package：Wooden Case, Carton Box
• Specification：Customized
• Trademark：ChengTan
• Origin：Chengdu
• Production Capacity：2000 Pieces Per Month

Basic Info.

Model NO. Drilling Bits Color Requirement Size 12", Customized Machine Type Drilling Equipment Application Mining Advantage High Wear Resistant Weight 140 Kg Warranty 1 Year MOQ 5 PCS Transport Package Wooden Case, Carton Box Specification Customized Trademark ChengTan Origin Chengdu Production Capacity 2000 Pieces Per Month

Product Description

Reverse Circulation Drilling Rig Reverse Circulation Drilling Hammers and Bits

Product Description    

Reverse Circulation Drilling Rig Reverse Circulation Drilling Hammers and Bits, It provinces a max rotary efficiency of tunneling.The good lubricating ability  and seal make the cutter can be used in underwater. Tungsten carbides feasible for soils to hard rocks, including sand stone, limestone, dolomite, tuff, granite.


Products Show

RCD Roller Metal Cutter Drill Bits are designed with the latest technology and advanced manufacturing processes. The cutters are proved with good performance and serviceability, and we provide advanced technical products and solutions for the mining, water well and construction industries.

We also provide the design and process service according to the requirements of customers.

1. Sink Ratio
The sink ratio which related to depth of air water mixer sinking under water is key to whole reverse circulation drilling system's working efficiency
Below formula is how to calculate the sink ratio:
m = h1/(h1+h2)
m= Sink ratio
h1= height from water surface to outlet tube
h2= height from position of air water mixer to water surface
In General, m >=0.5, when m<0.5, the efficiency of fluid flowing up is lower, even fluid not flowing up at all.
For reverse circulation drilling system, the bigger of sink ratio (m), the more powerful of driving force, which can overcome the difficulties during drilling, such as collapse of well wall, leakage, increasing of resistance etc. Meanwhile, it can achieve high drilling efficiency.
For the depth of air water mixer in water, it can be fixed when the sink ratio is decided.

2. Air Pressure
Due to the principle of gravity, 10 m high water column is equal to 1 bar, 10 m = 1 bar = 0.1 Mpa. For example, for 400 m depth well hole with 200 m length dual wall pipe, the air compressor with 20 bar output pressure is ok in theory. But considering the back pressure and leave some buffer as well from safety point of view, we should select the air compressor with 25 bar output pressure

3. Discharge Rate
Recommended discharge rate is 20 - 33 m/s, The lowest rate can not be less than 15 m/s.

4. Air Flow

BV=AV/AA
BV = Bailing Velocity = m/min
AV = Air Volume = m3/min
AA = Area of Annulus
Based on the formula above and the recommended discharge rate, the required air flow can be gained.

5. Total Length of Dual Wall Pipe
The length of dual wall tube is in direct proportion to hole depth, The recommended dual wall tube length is one third to half of hole depth

6. Diameter of Dual Wall Tube
It is better to get bigger diameter for dual wall pipe if possible, the basic request is tube dia. > 1/10 of hole dia.

7. Hole Depth
The reverse circulation drilling can not be used for borehole depth less than 1o m and normally it is used after 50 m depth for well drilling

Above is just Hardrock's general summary based on our engineers many year's experiences on borehole drilling area, for any specific application, it has to be considered specifically.





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Packing & Delivery

Packing Details  : Wooden Cases and Carton Boxes.
Delivery Details : 3-30 days after order


Various way to deliver the parts
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