Development of experimental apparatus about reverse circulation bit

A set of experimental apparatus on reverse circulation bit are developed, in order to lucubrate the mechanism of the new type reverse circulation bits, and the structure of the bits influencing the ability of taking core and carrying powder. Both the major structure of the equipment and the procession of experiment are described.     

Optimization of reverse circulation bit based on field experiment

By field experiment in Sandaozhuang W-Mo mining area in Luanchuan of Henan Province, the authors analyzed the Experimental result of reverse circulation bit on the basis of different structures and obtained the following conclusion ： the design parameter of reverse circulation bit, the number, diameter and angle of the spurt hole can influence on the reverse circulation effect. The bit with inner spurt hole is better obviously than that one without inner spurt hole in reverse circulation, one or two right and the best choice of inner spurt hole is that the diameter is Φ8, the angle is 30° dip up and the suitable number is two to three.     

Optimization of reverse circulation bit based on field experiment

By field experiment in Sandaozhuang W-Mo mining area in Luanchuan of Henan Province, the authors analyzed the Experimental result of reverse circulation bit on the basis of different structures and obtained the following conclusion: the design parameter of reverse circulation bit, the number, diameter and angle of the spurt hole can influence on the reverse circulation effect. The bit with inner spurt hole is better obviously than that one without inner spurt hole in reverse circulation, one or two right and the best choice of inner spurt hole is that the diameter is Φ8, the angle is 30° dip up and the suitable number is two to three.     

Numerical simulation and experimental research on air reverse circulation bit interior fluid territory

By using fluent fluid engineer emulator software to simulate negative pressure formed inside the injector added in the reverse-circulation sampling drilling bit, at six angles of 15, 30, 45, 60, 75 and 90 degrees. The pressure distributing nephogram and the corresponding numerical value gotten compared with the experiment data received by an injector with 6 angles designed by emulation the conclusion. It has been found that the two values are coincident essentially. The article shows that using emulator technology to design optimizely is credible and simple. The cost is low and the design cycle is short compared with the method through experience and test.     

Numerical simulation and experimental research on air reverse circulation bit interior fluid territory

By using fluent fluid engineer emulator software to simulate negative pressure formed inside the injector added in the reverse-circulation sampling drilling bit, at six angles of 15, 30, 45, 60, 75 and 90 degrees. The pressure distributing nephogram and the corresponding numerical value gotten compared with the experiment data received by an injector with 6 angles designed by emulation the conclusion. It has been found that the two values are coincident essentially. The article shows that using emulator technology to design optimizely is credible and simple. The cost is low and the design cycle is short compared with the method through experience and test.     

Calculation of flow distribution in air reverse circulation bit interior fluid field by simplifying air flow model

By simplifying the characters in the air reverse circulation bit interior fluid field, the authors used air dynamics and fluid mechanics to calculate the air distribution in the bit and obtained an equation of flow distribution with a unique resolution. This study will provide help for making certain the bit parameters of the bit structure effectively and study the air reverse circulation bit interior fluid field character deeply.     

Calculation of flow distribution in air reverse circulation bit interior fluid field by simplifying air flow model

By simplifying the characters in the air reverse circulation bit interior fluid field, the authors used air dynamics and fluid mechanics to calculate the air distribution in the bit and obtained an equation of flow distribution with a unique resolution. This study will provide help for making certain the bit parameters of the bit structure effectively and study the air reverse circulation bit interior fluid field character deeply.     

Air flow calculation of reverse circulation drilling technique with air DTH hammer

Air DTH hammer has been successfully applied in minor-caliber solid mineral exploration,water-well drilling and other drilling areas.In order to expand the applications of the technology,the authors further studied the principle and analyzed the mechanism of reverse circulation drilling technique with air DTH hammer to get the perfect assembles of equipments by optimizing working parameters.No parameter seemed more important than the air volume because it could maintain the working performance stability.The minimum air volume is related to the parameters such as depth and pressure,which was calculated under the actual conditions.It was solved for the air injection flow tables of the air DTH Hammer working at the different pressures.According to the data tables,operators could adjust the air volume to meet the demand on this technique,which had a realistic guiding significance.So it could build up a set of systematic and complete hi-technique.     

Reverse Circulation DTH Hammer Drilling Technique

The technical characteristics and operational principal of the reverse circulation DTH hammer drilling technology is integrated introduced in this paper. Using simulation technology to assist the drill...     

Design of a new bionic diamond bit and its experimental study

Bionics was applied in the design of the impregnated diamond bit. Based on previous research and the 63# bit matrix formula, a new non-smooth bionic impregnated diamond bit with a single circular ring was designed and manufactured, and also tested indoor. The results were satisfactory. During its shape contacted surface system, non-smooth shape display some structure merits such as decreasing resistance. It was obvious that the drilling efficiency of the bionics bit is much higher than that of ordinary’s one, and so does the working life of bionic bit.     

Repacking practice for G-3 engineering driller power unit with drive shaft of dual channel reverse circulation

In order to satisfy operating requirements for constant core drilling technology in reverse circulation with hollow-through DTH,the power unit of G-3 engineering driller was ameliorated. The new one with dual channel drive shaft, achieved the perfect assemble with transmission structure of the original power unit. It could interconvert according to need by using two sets of drive shafts with direct and reverse circulation. The repacked G-3 engineering driller carried on experiment in the field test in Luanchuan molybdenum mine of Henan, whose effect was very good.     

Repacking practice for G-3 engineering driller power unit with drive shaft of dual channel reverse circulation

In order to satisfy operating requirements for constant core drilling technology in reverse circulation with hollow-through DTH, the power unit of G-3 engineering driller was ameliorated. The new one with dual channel drive shaft, achieved the perfect assemble with transmission structure of the original power unit. It could interconvert according to need by using two sets of drive shafts with direct and reverse circulation. The repacked G-3 engineering driller carried on experiment in the field test in Luanchuan molybdenum mine of Henan, whose effect was very good.     

Reliability analysis of retractable drill bit with air reverse circulation used for drilling while casing

Casing-while-drilling(CWD) with down the hole(DTH) hammer drilling technology has been widely used in unconsolidated formations,due to its advantages in protecting the borehole wall,excellent rock cuttings capacity,and fast penetration rate in hard rock.As an important component of the CWD system,the structure of the retractable drill bit needs not only to ensure to form stronger reverse circulation,but also to be expandable or retractable as needed,otherwise the drill bit cannot be lift and put...     

Development and Extension of Seawater Desalination by Reverse Osmosis

Seawater desalination has been people‘s fond dream since ancient times,the dream is now becoming a reality.This paper presents a brief development history of reverse osmosis.Much attention was paid to innovative development in mebranes,modules.equipments and applied technology,including asymmetric and composite membranes,spiral-wound element and hollow fiber module,energy recovery equipments and different technological processes.The extension of reverse osmosis,such as desalination,pre-concentration,integrated processes and nanofiltration,is also briefly mentioned.     

Study on drilling mechanism and optimization of percussion-extruding DTH hammer bit

The authors tested the percussion-extruding Down-the-hole(DTH)hammer bit with five different structures and mainly analyzed the drilling mechanism between conical bit and stepped bit. In addition, aiming at "the pile effect" in combination with the advantage of stepped bit, we design a new cam spinning bit and test it outdoors. The result shows that using cam spinning bit can solve the problem of "the pile effect", which can also obtain higher drilling efficiency than using conical bit in high confining pressure strata. It is characterized by novel structure and high drilling speed as well as good guiding, and it is significant for improving efficiency in percussion-extruding drilling technique.     

Study on drilling mechanism and optimization of percussion-extruding DTH hammer bit

The authors tested the percussion-extruding Down-the-hole （DTH）hammer bit with five different structures and mainly analyzed the drilling mechanism between conical bit and stepped bit. In addition, aiming at ＂the pile effect＂ in combination with the advantage＇ of stepped bit, we design a new cam spinning bit and test it outdoors. The result shows that using cam spinning bit can solve the problem of ＂the pile effect＂, which can also obtain higher drilling efficiency than using conical bit in high confining pressure strata. It is characterized by novel structure and high drilling speed as well as good guiding, and it is significant for improving efficiency in percussion-extruding drilling technique.     

A study on the baroclinic structure of the abyssal circulation

In this paper, the linear continuously stratified ntxiel of the abyssal circulation proposed by Pedlosky (1992) was emended to include the second order term - (γθm) in the vertical turbulent mixing pararneterization of - (ω‘θ‘）x = kvθxx- θxxx, in which kv is a vertical diffusion coefficient,and γ is the second order coefficient of turbulent mixing (or simply called γ-term and γ＜0 is only allcmed). The influence of the γ-tema on the baroclinic structure of the abyssal circulation driven by up-welling out of the abyss was investigated, It was found that the γ-term has a noticeable influence on thebaroclinic structure of the upwelling driven abyssal circulation. For uniform upwelling, it favors the baroelinic layering of the abyssal circulation in the eastern part of the basin, but prevents the layering in thewest. In addition, this parameter was found to decrease the vertically averaging meridional velocity of theabyssal circulation frcrn the west to the east on the southern boundary. For upwelling localized near theeastern boundary, the γ - term favors baroclinic layering of the abyssal circulation in the whole basin.Especially, on the southern boundary the γ - term could strengthen the vertically averaging meridional ve-loeity in the west, but gready weaken it in the east. The ntntel presented here might be considered as anextension of the Pedlosky baroclinic ntntel of the abyssal circulation.     

大气环流异常对云南8月低温的影响

应用1951-2005年NCEP/NCAR月平均再分析资料与云南8月气温资料进行相关分析,发现在云南8月低温年,位势高度场的显著相关区在欧亚大陆地区具有"- -"的波列结构,显著相关区在副热带地区表现也较好;据此讨论了云南8月低温发生时的大气环流特征,得出200hPa南亚高压偏弱,500hPa欧亚大陆西风槽脊异常发展,副高偏弱是导致云南8月低温的主要原因.     

Seasonal evolution of circulation and thermal structure in the Yellow Sea

In this paper, the authors used the Princeton Ocean Model (POM) to simulate the seasonal evolutions of circulation and thermal structure in the Yellow Sea. The simulated circulation showed that the Yellow Sea Warm Current (YSWC) was a compensation current of monsoon-driven current, and that in winter, the YSWC became stronger with depth, and could flow across the Bohai Strait in the north. Sensitivity and controlling tests led to the following conclusions, In winter, the direction of the Yellow Sea Coastal Current in the surface layer was controlled partly by tide instead of wind, In summer, a cyclonic horizontal gyre existed in the middle and eastern parts of the Yellow Sea below 10 m. The downwelling in upper layer and upwelling in lower layer were somehow similar to Hu et al. (1991) conceptual model. The calculated thermal structure showed an obvious northward extending YSWC tongue in winter, its position and coverage of the Yellow Sea Cold Water Mass in summer.