For the rig, the third point is suitable tools. First, generally speaking, If the hole depth is over 20 meters, DTH and Rotary Drill hole’s straightness is significantly higher than the top hammer. But in addtion, since the top hammer drilling rig is a full hydraulic multi, from the point of energy conduction, hydraulic is higher efficiency,lower […]
This article will elaborate on the third element, namely the inherent requirements of the rig: holes location and drilling . For the rig, if positioning is not correct, a direct result is drilling deviations ,which will affect the subsequent blasting effects and costs. In daily drilling operations, there are two kinds of holes, vertical and with angel. Vertical hole drilling is relatively easy, the easiest way is to promote the two pointers installed on the two vertical surfaces of the girder ,you can basically observe the vertical angle. However, in reality, most of the drilling are angled in three dimensions, much more complex than the vertical hole. If you pursuit precise drilling direction, then we need satellites’ help. Currently there are two better systems, Sandvik TIM 3D system,and Atlas Copco HNS system, The basic approach is : 1. Satellite scan the surface, then get the surface data 2. Regarding to the surface data and drilling requirements, develop detailed programs 3.The program is transmitted to the rig cab’s receiving apparatus 4.Does not require artificial drilling hole, satellite device will record the coordinates of each hole 5.Drillers see the screen, through the control handle to adjust to orginal drilling program, then complete the accurate positioning, begin holes drilling .(Sensor and positions receiver device on the rig will inform the drillers that if the position is accurate via screen. ) 6.Besides the angle, depth settings can also be realized simultaneously. (Reducing the error of depth lack or excessive ).There’s even automatic switching rods function.Most of time, drillers just need to sit in front of the screen to work. Under the ensurance of accurate position, the next step is drilling. First, we must ensure the girder against the work surface completely, Otherwise, there will be deviation of the opening direction,at the same time, its runaway reaction also cause damage to the drilling rig and tools. Second, on the surface, it is not advisable that take the whole forward, which be likely to cause deviation, but we should move slowly in the beginning, when full access to the rock joints increase the power. Now, some advanced imported equipment in the opening part has intelligent control,but can not be completely accurate, also need drillers’ experience,to achieve accurate openings.
As we all know, the errors in drilling depth and angle can cause the following problems: 1.safety risks: flying rocks and other issues 2. Low productivity, high total cost: blasting poor, squib or deflagration, causing chunks of rock burst rate, flying stone, increase the cost of the follow-up process. 3. High drilling consumption: drilling errors will reduce tools life and increase cost. Threaded bits DTH bits DTH hammer In order to reduce the error, we can do mainly from four aspects: First, and most important, a competent driller A good driller must know how to conduct the drilling program perfectly,(Work on the location and opening directly determine the accuracy of the angle and depth of the drilling),meanwhile, do the best to avoid lost productivity caused by sticking and drilling consumption. Second, according to the drilling program and blasting rock properties to select the appropriate drilling methods, or based on existing equipment to adjust the drilling and blasting program. Suppose a working scenario: a step height of 20 meters, […]