Water drilling illustration
As water is incompressible, benefits as higher efficiency, higher pressure and lower losses are achieved. Wassara normally uses up to 300 litres per minute of clean water with a pressure of up to 180 bar.
The Wassara technology uses water to power the down-the-hole (DTH) percussion hammer. This makes it the ideal choice for most drilling applications where air-powered DTH hammer, top hammer or core drilling equipment are normally used.
The DTH hammer
The heart in Wassaras water-powered drilling technology is the hammer. It's a Down-The-Hole hammer (DTH) and is connected directly to the drill bit. Wassara normally uses up to 300 litres per minute of clean water with a pressure of up to 180 bar.
The DTH technology is far better than top hammers as no power is lost through the drill string during operation. This simple fact enables the hammer to operate at any borehole length. It doesn't matter if the borehole is 10, 100 or 1 000 meters long, the high efficiency remains through the whole distance. When leaving the hammer, the pressure is reduced to ambient pressure as it is an open system.
Incompressible power
As water is incompressible, benefits as higher efficiency, higher pressure and lower losses are achieved. It also enables the use of small borehole dimensions. Wassaras water-powered DTH hammers can be used for borehole sizes from 60 to 254 mm.
Drilling technologies over the years
The mechanised drilling in mining operations started some 140 years ago with the invention of the pneumatic top hammer. Productivity demands have forced development in new technologies, and the possibility to drill long and straight holes gave a huge step in this direction. The most recent major innovation in drilling came with the water-powered DTH hammer from Wassara.
Wassaras water-powered DTH hammer is the most environmentally friendly percussion drilling method existing today. The DTH hammer is powered by water. No oil is used for lubrication, meaning no contamination of air or water. The water is effectively suppressing dust as well.
The incompressibility of water is a key factor allowing the features of the Wassara hammer system. It also gives a major energy cost saving compared to air DTH technology, and reduces the energy demand to power the hammer.
Pictures: LKAB photo archive
Wassara applications
A selection of applications where drilling with Wassara makes a difference:
• Grout holes in dams and ground engineering
• Jet grouting
• Sensitive formations
• Casing advancing
• Precollaring in mineral exploration
• Long holes in underground mining