How to Choose a DTH Hammer?

Table of Contents

The DTH hammer is an integral part of the down-the-hole drill and belongs to the working device of the down-the-hole drill. It is mainly used to convert the energy of compressed air into the impact energy of breaking rocks. It has reliable working performance and is widely used in metallurgy, coal, chemical industry, water conservancy, hydropower, highway, railway, national defense, construction, and other engineering hole-forming operations. It is an ideal drilling and blasting equipment. But there are so many types, how to choose them, does it bother you?

If you want to choose a suitable DTH hammer, you first need to understand its type and working parameters.

Types of DTH Hammers

DTH drilling tools

1. According to the pressure level, the DTH hammer can be divided into low-pressure DTH hammer, medium-pressure DTH hammer, and high-pressure DTH hammer.

2. According to different structures, DTH hammers can be divided into valved and non-valved.

Under low pressure, there is no obvious performance difference between the valve and non-valve type hammer. In terms of achieving impact action, the valved type is more advantageous and easy to debug; in terms of single impact energy, under the same weight as the piston, the valved type has greater impact energy. Because of the successful application of the high-pressure compressor, the high-pressure valveless type shows high performance and low energy consumption, which makes the DTH hammer change from the valved type to the valveless type.

3. According to different performance parameters, DTH hammers can be divided into high-frequency and low-energy types and high-energy and low-frequency types.

But no matter which of the above DTH hammers should have an air intake and backstop device, impact gas distribution mechanism, and anti-aircraft force blowing device (it can realize two functions, 1. When the drill bit does not touch the rock, the hammer does not carry out impact action to prevent air drilling from damaging the drill bit. 2. When the rock slag in the drilling hole cannot be discharged smoothly, lift the drill bit from the bottom of the hole, stop the impact, and use all the compressed air for slag discharge.), drill bit hanging device and exhaust slag-blowing device.

Working parameters of DTH hammer

DTH hammer

The geometric parameters of drilling, working air pressure, and rock firmness coefficient are the original parameters for designing the DTH hammer, from which the corresponding air distribution size can be determined, and thus the ideal impact power and impact frequency can be obtained. Therefore, a specific hammer can only exert the best rock drilling effect under specific working air pressure, working parameters, and lithology.

Three main working parameters:

Working air pressure

The higher the working air pressure, the faster the rock drilling speed will be if the appropriate hammer is selected. The hammer is designed according to a specific pressure, and its performance is optimal only within a given design pressure range. Using the hammer away from the design pressure value will not only fail to exert its due efficiency but will cause the hammer to fail to work or fail prematurely. Therefore, according to the pressure level to match the corresponding hammer.

Impact energy

The impact energy of the hammer must ensure the unit-specific energy of the drill bit so that it can effectively break the rock to obtain a more economical rock-crushing ratio energy consumption and higher drilling speed. If the impact energy is too large, it will not only cause a waste of energy but also shorten the service life of the drill bit; if the impact energy is too small, it will not break the rock effectively and reduce the drilling speed. Different rocks need different rock crushing ratio energy consumption, and therefore need to choose different impact power hammers.

Shock frequency

Generally, when the impact energy is constant, the higher the impact frequency, the greater the impact power, but the outer diameter of the hammer is limited by the diameter of the drilled hole. The higher the impact frequency, the smaller the impact energy. Therefore, the increase of the impact frequency is limited by the specific energy consumption of rock crushing.

To sum up, the choice of the DTH hammer is inseparable from its working parameters, such as working air pressure, drilling size, and rock characteristics, we can choose the DTH hammer accordingly.

Selection of DTH hammer

1. According to the pressure level of the working compressed air, reasonably select the corresponding level of the DTH hammer.

2. Select the corresponding type of DTH hammer according to the drilling diameter.

3. Select the corresponding DTH hammer according to the solidity of the rock. For soft rock, it is recommended to use high-frequency and low-energy hammers, and for hard rocks, it is recommended to use high-energy and low-frequency hammers.

Although it is important to choose the right DTH hammer, it is more important to choose a quality DTH hammer supplier. Because of a quality DTH hammer suppliers can directly provide customized solutions for customers to meet their needs and escort their projects.

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