The cluster hammer and other DTH (Down-The-Hole) drill bits are both used in drilling operations, but they have some key differences in terms of design and functionality.
Here are the main differences:
Structure: A cluster hammer consists of multiple hammer heads arranged in a cluster configuration. Each hammer head operates independently but within the same drilling assembly. On the other hand, a DTH drill bit is a single unit with a cutting structure designed to penetrate the ground.
Drilling method: A cluster hammer operates by delivering impact forces to the drilling bit through the rotation and vibration of multiple hammers. This combination of rotational and vibratory motion helps in penetrating hard rock formations. In contrast, a DTH drill bit relies solely on the impact force generated by a single piston hammer hitting the back of the bit, which then transfers the force to the cutting structure.
Drilling efficiency: Cluster hammers are known for their high drilling efficiency, particularly in hard and abrasive formations. The use of multiple hammers distributed across the drilling face enables faster penetration rates compared to single DTH drill bits. The impact forces from the multiple hammers are concentrated on a smaller area, allowing for more effective drilling in challenging ground conditions.
Hole size and diameter: Cluster hammers are typically used for larger-diameter drilling applications, such as foundation drilling or piling, where boreholes with a diameter of several meters or more are required. DTH drill bits, on the other hand, come in a range of sizes and are used for various drilling applications, including water well drilling, mining, and construction, with hole sizes typically ranging from a few inches to several feet.
Versatility: DTH drill bits offer greater versatility compared to cluster hammers. Different types of DTH drill bits can be used for specific drilling conditions, such as soft rock, hard rock, or mixed formations. They can be easily interchanged based on the specific requirements of the drilling project. Cluster hammers, on the other hand, are more specialized and primarily used in applications where large-diameter drilling is required.
It's important to note that both cluster hammers and DTH drill bits have their own advantages and are suitable for different drilling scenarios. The choice between the two depends on factors such as the specific drilling requirements, ground conditions, desired drilling efficiency, and hole size considerations.