Adriatech drilling tools - attrezzature di perforazione

Service and tuning kits

In abrasive drilling conditions, partly external components of the DTH hammers are subject for excessive flush blasting and is wearing out before the internal parts reaches their fatigue limits.

Wear often appears on the chuck itself or on the cylinder at the chuck-end. For this reason many of the Terranox hammers are designed with reversible cylinders. With help of defined service kits the hammers can be rebuilt and most internal parts re-used for another run. Use of service kits, extends the total hammer life and substantially reduces the total drilling cost, as the cost for service kits is only approximately 10% of a new hammer Terranox hammers are, for optimized drilling performance and hole cleaning, fitted with choke plugs to enable a ultimate tuning of the hammer for each occasion and use.

Replacement choke plugs are included in the Terranox tuning kits. For easy logistics defined kits containing the vital parts are available for each hammer.

Selecting the right hammer

The optimum range of hole size for blast hole drill- ing with DTH is 90 mm to 254 mm (3 ½"-10"). Smaller blast holes are generally drilled using tophammer, and larger holes generally use rotary machines.

In other applications, like foundation drilling, DTH hammers can be used with single bit in hole sizes up to 914 mm (36"). With multiple hammer units CD (Cluster Drills) drill holes up to 70" or 1778 mm as standard. Larger cluster drills can be delivered as per customer request.

As a rule of thumb, the smallest hole diameter a DTH hammer can drill is its nominal size. A 4 inch hammer will drill a 4 inch (102 mm) hole.The limiting factor is the outside diameter of the hammer, because, as hole diameter reduces, airflow is restricted. Maximum hole size for production drilling is the nominal hammer size plus 1 inch, so for a 4 inch hammer the maximum hole size is 5 inch (127-130 mm).

Choosing the right hammer is largely determined by hole size and type of rock formation. Ideally, the size of the hammer should match the required hole dimension as closely as possible, leaving just enough space for cuttings to evacuate the hole. Secoroc hammers are purpose-matched for all rock types and applications. Where high performance is the main criterion, Secoroc COP Gold hammers or the new 6" COP 66 hammer are recommended in blast hole drilling and Secoroc QLX hammers in deep hole drill- ing applications.The QLX hammer has proven superior performance and adaptability to different air require- ments thanks to the Air Select System.

Where proven technology is required, the Secoroc COP and QL hammers are known for their reliability and longevity.They are practically bullet proof, making them useful for production drilling in quarries, shallow water well drilling, and underground blasthole drilling.

QM is similar to Standard, but with heavy duty chuck and wear sleeve, and a top sub fitted with tungsten car- bide buttons for wear protection in harsh and abrasive conditions.These also protect the top sub from exces- sive wear when rotating out of the hole through broken rock.

QL HAmmers

Selecting the right bit

Atlas Copco Secoroc has a comprehensive range of DTH drill bits to match all conceivable applications. Each bit is made from quality alloy steel, and has been precision machined to produce a perfect body, heat treated to the required hardness, given surface compression for fatigue resistance, and fitted with precision buttons manufactured in-house.

Five basic designs are available: Convex, Flat front, SpeedBit, Concave, and RocketBit.These are designed for specific applications for all rock types, hardness's and conditions.

Bit life and rate of penetration are the most important criteria in selecting the right bit for a particular application. In most cases, the focus is on productivity, so the fast cuttings removal features of the SpeedBit and Convex/Ballistic designs are preferable, to ensure the buttons are cutting clean, with the minimum of recrushing. In hard and abrasive formations, however, the flat front design offers best bit life, having strong gauge rows with large spherical buttons which are easy to regrind and maintain.The SpeedBit offers improved productivity with the same gauge as the Flat front, but with ballistic buttons in the front for faster penetration.

An alternative is the Concave design with spherical buttons. The RocketBit can be dressed with ballistic buttons for use in soft to medium hard formations where fractured rock can be expected, or can be supplied with spherical buttons for hard and abrasive formations. Bits are manufactured to match all diameters of Secoroc hammers.

Drill bits standard assortment

For proper selection of Terranox hammer to match casing diameter, please use cross reference table below. Casing size and drilling conditions will be decisive factors when selecting casing advancement system.

The Terranox hammer range is designed for a maximum working pressure of 25 bar. In overburden drilling applications the air pressure is normally recommended to be kept in the range of 12-14 bars. However, for proper hammer performance throughout the entire drilling operation, the compressor model should be selected to match the corresponding maximum hammer air consumption, shown below.

For proper hammer performance, the geotechnical drilling rig should be equipped with a rotation unit providing minimum torque as per the table shown below.

Atlas Copco Secoroc's reverse circulation hammers are specifically designed for all kind of exploration drilling (deep hole and pit grade control applications).

Whether you are exploring potential sites or working an existing mine, the Secoroc RC hammer will assure of high performance, exceptional reliability and dependable support.


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