Double Casing/ Head Rotary System

Double Head Rotary System, Double Casing Drilling Tools

Rock drilling tools manufacturer ProDrill:

The two rotary heads are typically mounted on separate sleds which can be adjusted independently to control the position of the inner string in relation to the casing bit.

The inner bit can be advanced in front of the casing bit to act as a pilot bit for the casing string or it can be retracted inside the casing crown reaming bit to better contain flushing inside the casing.

Outer Diameter: 133mm

In combination with a DTH system on the inner drill string, a Rotary-Rotary system is able to achieve deeper depths compared to drifter (top hammer) based systems.

Double head Rotary-Rotary systems are a preferred method for drilling straight, deep holes. These systems offer the driller a high level of flexibility and control to deal with varying ground condition
 
Two Independent Rotary Heads
Separately drives the outer casing and the inner drill string and are typically mounted on separate sleds which can be adjusted independently to control the position of the inner string in relation to the casing bit.
Casing bits for dual rotary systems are ring bits with tungsten carbide inserts.
The carbide insert is typically a scraping type.

Male/female friction welded double-start rotary percussive casing

Application range

Suitable for geothermal drill for grouting, sampling, water well drill, foundation drill etc.

Working principles

By using water or compressed air the discharge head make the casing tube and drill rod rotate and penetrate

Product Features: 
1.Hardening treatment of the parts surface with longer operating life
and excellent anti-wear properties
2.Structure optimization Strengthen the structural
3.Superior performance Smooth with high efficiency

Double casing system with crown reaming bit, inner opener bit, assembly