How to choose the model of crawler DTH drilling rig (One)?

Dec. 31, 2019

Down-the-hole drilling rigs are used more and more widely in grouting operations, and most of the grouting reinforcement is open-air operations. This article mainly discusses how to choose the model of crawler mounted DTH drilling rigs.

1.Selection principle

(1) Applicable in production

The selected drilling rig should meet the needs of the project construction, and should be reasonably configured according to the construction tasks undertaken by the enterprise under normal conditions, taking fully into account the scope of application of the drilling rig. Demand, only the drilling rig with strong applicability in production can better show its investment effect.

(2) Technically advanced

While meeting production needs, it is required to maintain its advanced performance indicators, which is conducive to extending its technical life. It will face obsolescence in the short term. In the long run, it meets the requirements of sustainable development of enterprises and can more effectively protect investment.

(3) Operability and maintainability

Simple operation, convenient for workers to master the operation skills, and shorten the time of auxiliary operations, such as site leveling, rig displacement, rig lifting, drill rod replacement, gas and water valve adjustment, etc.

The structure of the hydraulic drilling rig is simple and easy to repair, the universality of accessories is strong, and sufficient supply of supplies can reduce the purchase price of accessories, equipment operation and management costs. Rig maintenance is difficult, technical support and after-sales service are guaranteed. When the machine fails, on-site maintenance workers can repair it in time, which can avoid delaying construction and production due to waiting for technical rescue from the manufacturer.

(4) Safety and environmental performance

At present, the country attaches great importance to the safety and environmental performance of products. When purchasing new equipment, attention should be paid to manufacturing materials, whether various safety devices are complete, construction work noise, and whether exhaust gas and waste emissions meet relevant national regulations.

(5) Economically reasonable

It is required that the purchase price of the equipment is reasonable, the energy consumption and maintenance costs are low during use, and the investment recovery period is short to facilitate the capital flow of the enterprise.

Crawler Mounted DTH Drilling Rig

Crawler Mounted DTH Drilling Rig

2.Selection of technical parameters of rig

The grouting operation is mainly carried out by a down-the-hole drill in the required depth and diameter of the subgrade to be reinforced. After the drilling is completed, the cement slurry is injected into the soil layer from the hollow drill pipe of the drill through the grouting pump, so that The voids or pores in the body are filled with slurry and solidify. The air compressor provides compressed air for the rig impactor, drives the impactor piston to reciprocate, completes impact drilling, and blows out slag. Therefore, when comparing the technical parameters of DTH drill rigs, it is necessary to take into account the technical indicators and economics of the supporting air compressors.

(1) Working surface hardness

Different rocks have different hardness indexes and drillability are also different. Ruggedness is often used to indicate how easy it is to break a rock. The size of the firmness is expressed by the firmness coefficient. The firmness coefficient is also called the hardness coefficient, which is also called the Platts hardness coefficient f value.

According to the construction geological conditions, the DTH needs to choose a DTH drill rig that adapts to the hardness of the working face of the construction, and it is necessary to choose a drill, drill pipe, and impactor of the same construction. Rock hardness is the key to the efficiency of drilling rigs. Small-scale down-the-hole drilling rigs are most suitable for ore rocks below medium hard.