Design Optimization and Performance Analysis of the Pneumatic DTH Hammer with Self‐Propelled Round Bit

Bo, Kun; Sun, Shida; Hu, Yong; Wang, Maosen

doi:10.1155/2021/6653390

Cited by 8 publications

(4 citation statements)

References 21 publications

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“…This transducer can record the motion of the piston under varying conditions of different working pressures, such as velocity, acceleration, displacement, and impact frequency. All of the experimental data captured by high-speed data acquisition are used to precisely record and analyze the operational status of the hammer [23].…”

Section: Experiments Validation Of Structural Designmentioning

confidence: 99%

Design optimization and feasibility analysis of pneumatic DTH Hammer with self-rotation bit

Wang¹,

Bo²,

Chen³

et al. 2022

J. vibroeng.

Self Cite

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This paper presents a novel pneumatic Down-The-Hole (DTH) hammer with self-rotation bit used for rock drilling, and the mechanical structure and working principle are mainly covered. A unique mechanism with ratchet and pawl incorporated in pneumatic DTH hammer is proposed for percussion-rotation drilling to break rock. The drill bit can rotate while the drill pipe stays still because of the structure design and reduces the friction between the drill pipe and borehole. Firstly, the rationality of mechanical invention is verified via the finite-element software ANSYS and the numerical simulation of impact dynamics. Moreover, the energy transfer regulation is revealed in the impact process under differential final impact velocity, which can help practical experience in mechanical design. Finally, based on the experimental study on the novel hammer, we found that its function can satisfy the requirement, as well as overall performance, was improved.

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Section: Experiments Validation Of Structural Designmentioning

confidence: 99%

Design optimization and feasibility analysis of pneumatic DTH Hammer with self-rotation bit

Wang¹,

Bo²,

Chen³

et al. 2022

J. vibroeng.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Zhukov et al [10] designed a hammering piston of a DTH air hammer with curvilinear-free surfaces, and this structure ensures that there is no contact with the piston and the DTH body, so rock breaking impact is generated with the minimum energy input. Bo et al [11] proposed a novel pneumatic DTH hammer, the biggest feature of which is that it has a self-propelled round bit. The purpose of designing this self-propelled round bit is to surmount the problems such as drilling tool wear in directional drilling, and working principles and performances of this new pneumatic DTH hammer are analyzed based on a nonlinear dynamic model.…”

Section: Introductionmentioning

confidence: 99%

Simulation and Analysis of a Split Drill Bit for Pneumatic DTH Hammer Percussive Rotary Drilling

Shi,

2024

Geofluids

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Reverse circulation impact drilling has the advantages of high drilling efficiency and less dust, which can effectively form holes in hard rock and gravel layer. As integral reverse circulation drill bits used in the conventional down-the-hole (DTH) hammers are only suitable for specific formations, the whole set of DTH hammer needs to be replaced when drilling different formations. In this paper, several types of split drill bits for different drilling technologies are designed. The flow field characteristics of one of the split drill bits is analyzed based on the computational fluid dynamics (CFD) method, with four technic parameters considered, which are input flow rate, number of inlet holes, angle of injection exhaust holes, and diameter of injection exhaust holes, respectively. Three parameters are selected as indicators to evaluate the rationality and performance of the split drill bit, which are injection exhaust hole outlet mass flow rate, ratio of the mass flow rate out of injection exhaust holes to the whole inlet mass flow rate, and maximum pressure at the upper end of the split drill bit. According to the CFD analysis results, the above four technic parameters influence the flow rate and pressure in different rules. Considering the injection capacity, pressure loss, and bit strength, inlet holes of 10, injection exhaust holes with an angle of 50°, and injection exhaust holes with a diameter of 12 mm are recommended to obtain ideal reverse circulation. Different types of split drill bits were manufactured, and drilling experiments were carried out in unconsolidated formations. The maximum drilling rate can reach 1.5 m/min in the drilling experiments. The split drill bit proposed in this paper exhibits excellent adaptability for reverse circulation drilling in loose formations.

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“…The emergency rescue must be carried out after a mine accident, but poor rescue results and low efficiency can lead to the deaths of trapped miners [8]. Compared with the conventional mud drilling method, pneumatic DTH hammer drilling, as a percussive-rotary drilling technology, has a higher rate of penetration (ROP) and plays an essential role in mine emergency rescue [9,10]. Furthermore, as an underbalanced drilling technology, the DTH hammer can eliminate formation damage and ensure wellbore stability [11].…”

Section: Introductionmentioning

confidence: 99%

Optimum Design of Large-Diameter Reverse Circulation Drill Bit for Drilling Rescue Wells Using Orthogonal Experimental Method and CFD Simulation

Zhao

et al. 2023

Energies

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Down-the-hole (DTH) hammer drilling with reverse circulation is a novel, mobile, high-speed drilling system suitable for the specific requirements of mine rescue. This technology can be applied to shorten the rescue time during mine accidents. The performance of reverse circulation (RC) drilling depends on the structural design of the drill bit. An orthogonal experimental design is executed to investigate the effect of the structural design parameters of the large-diameter drill bit for drilling rescue wells on the cutting carrying capacity and reverse circulation performance. This study employs computational fluid dynamics (CFD) software to solve the Navier–Stokes equation for three-dimensional steady flow and calculate the flow field around the drill bit to evaluate the RC efficiency. Six key geometric parameters were proven to have a direct influence on the RC performance, including the diameter of suction nozzles Dn, the length of nozzles L, the quantity of nozzles N, the diameter of the pilot hole Dg, the inclination angle of nozzles θs, and the deflection angle of nozzles θd. The CFD simulation experiments were implemented according to the orthogonal array L18(37) and were analyzed using the range, variance, and regression analysis. A mathematical model was developed for the RC efficiency to understand the effect of the factors. The results show that the diameter of suction nozzles Dn has an essential effect on the RC performance of the drill bit. An ideal combination is Dn = 20 mm, L = 50 mm, N = 3, Dg = 50 mm, and θs = 35°, θd = 10°, which was obtained through variance analysis and validated via CFD simulation for higher efficiency. To verify its real performance, a large-diameter RC drill bit with a diameter of 1.2 m was manufactured and tested in the field. The result demonstrated that the drill bit had excellent cutting transport and reverse circulation performance.

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Design Optimization and Performance Analysis of the Pneumatic DTH Hammer with Self‐Propelled Round Bit

Cited by 8 publications

References 21 publications

Design optimization and feasibility analysis of pneumatic DTH Hammer with self-rotation bit

Design optimization and feasibility analysis of pneumatic DTH Hammer with self-rotation bit

Simulation and Analysis of a Split Drill Bit for Pneumatic DTH Hammer Percussive Rotary Drilling

Optimum Design of Large-Diameter Reverse Circulation Drill Bit for Drilling Rescue Wells Using Orthogonal Experimental Method and CFD Simulation

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