Results 11 to 20 of about 2,021,478 (258)
Reverse Circulation Drilling Method Based on a Supersonic Nozzle for Dust Control [PDF]
Applied Sciences, 2016 To reduce dust generated from drilling processes, a reverse circulation drilling method based on a supersonic nozzle is proposed. The suction performance is evaluated by the entrainment ratio.
Dongyu Wu +6 more
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Experimental and Numerical Analysis of Flow Behavior for Reverse Circulation Drill Bit with Inserted Swirl Vanes [PDF]
Geofluids, 2022 A swirling drill bit designed with an integrated vane swirler was developed to improve reverse circulation in down-the-hole hammer drilling. Its entrainment effect and influential factors were investigated by CFD simulation and experimental tests.
Cheng Yang +6 more
doaj +3 more sources
Air reverse circulation at the hole bottom in ice-core drilling [PDF]
Journal of Glaciology, 2019 Ice-core drilling to depths of 200–300 m is an important part of research studies concerned with paleoclimate reconstruction and anthropogenic climate change. However, conventional drilling methods face difficulties due to firn permeability.
ZHENGYI HU +7 more
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Analytical and experimental study of a reverse circulation drill bit with an annular slit [PDF]
Advances in Mechanical Engineering, 2016 A new type of drill bit designed with an annular slit was developed to enhance the reverse circulation effect of the down-the-hole hammer drilling technology. A computational fluid dynamics code, Fluent, was used to simulate the flow phenomena inside the
Pinlu Cao +4 more
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CFD-DEM Simulation of Reverse Circulation Pneumatic Cuttings Removal during Coal Seam Drilling [PDF]
Mathematical Problems in Engineering, 2020 To solve the problems that the borehole depth is shallow and the borehole formation rate is low during the gas drainage drilling in soft coal seam with current cuttings removal method, a new technology of reverse circulation pneumatic cuttings removal is
Xiaoming Han, Peibo Li, Jialiang Li
semanticscholar +2 more sources
Nuclear Engineering and Technology, 2020 In a sudden shutdown of primary pump or coolant loss accident in a marine nuclear power plant, the primary flow decreases rapidly in a transition process from forced circulation (FC) to natural circulation (NC), and the lower flow enters the steam ...
Mingrui Li +3 more
doaj +2 more sources
Advances in Civil Engineering, 2019 In the past decades, horizontal directional drilling (HDD) has been successfully used to install various pipelines in different strata. However, construction accidents such as drill-burying and drill-sticking occur occasionally when pipelines installed ...
Lingrong Kong +3 more
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IOP Conference Series: Earth and Environment, 2021 The reverse circulation drilling method is now widely accepted as an effective way of exploration and grade control. However, the performance of reverse circulation drilling operations is greatly affected by the filtration effect (lost circulation) and ...
Chinedu J. Okere +4 more
semanticscholar +2 more sources
Study on Change Rules of Factors Affecting Gas Loss during Coalbed Air Reverse Circulation Sampling
Advances in Civil Engineering, 2021 The gas loss in sampling is the root of coalbed gas content measurement error. The pressure and particle size have a significant impact on the gas loss.
Demin Chen +3 more
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Circulation of Dengue Virus Serotypes in the City of Makkah, Saudi Arabia, as Determined by Reverse Transcription Polymerase Chain Reaction [PDF]
The Canadian journal of infectious diseases & medical microbiology = Journal canadien des maladies infectieuses et de la microbiologie medicale, 2017 The present study was aimed to investigate the circulation of four dengue virus (DENV) serotypes in Makkah, Western Saudi Arabia. Blood samples were collected from 25 dengue fever-suspected patients and were subjected to molecular typing for DENV-1, DENV-
S. Organji, H. Abulreesh, G. Osman
semanticscholar +2 more sources