• Title/Summary/Keyword: Abrasive

Search Result 954, Processing Time 0.146 seconds

Influencing factors for abrasive flow rate and abrasive flow quality of abrasive injection waterjet systems for tunnel excavation (터널굴착용 투입형 연마재 워터젯 시스템의 연마재 투입량과 유동성에 미치는 영향 인자)

  • Joo, Gun-Wook;Oh, Tae-Min;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.16 no.4
    • /
    • pp.417-430
    • /
    • 2014
  • A new rock excavation method using an abrasive waterjet system is under development for efficiently creating tunnels and underground spaces in urban areas. In addition, an appropriate abrasive flow rate and abrasive flow quality are important for the new rock excavation (cutting) method using an abrasive waterjet system. This study evaluated the factors influencing the abrasive flow rate and abrasive flow quality, specifically the abrasive pipe height, length, tortuosity and inner diameter, through experimental tests. Based on the experimental test results, this study suggested optimal conditions for the abrasive flow rate and abrasive flow quality. The experimental results can be effectively utilized as baseline data for rock excavation methods using an abrasive waterjet system in various construction locations such as tunnels near urban surroundings, utility tunnels, and shafts.

Effect of Abrasive Processing in the Milling Process on the Quality of Rice (정백공정 중 연삭공정이 쌀 품질에 미치는 영향)

  • Kang, Tae-Hwann;Ning, Xiao Feng;Han, Chung-Su;Cho, Sung-Chan
    • Journal of Biosystems Engineering
    • /
    • v.35 no.3
    • /
    • pp.169-174
    • /
    • 2010
  • This study was conducted to investigate the effect of abrasive processing and non abrasive processing in the milling process on the quality of rice. The effect was analyzed based on the factor such as whiteness, grain temperature, moisture content, crack and broken rice ratio. The results were as followings. Whiteness of abrasive rice was the same as non abrasive rice. The rice temperature increase of abrasive rice was $1.6^{\circ}C$ lower than non abrasive rice. The crack ratio was increased in the process of milling and non abrasive rice showed higher values than abrasive rice. The broken rice ratio of the using abrasive processing was about 0.05% lower than that of non abrasive processing. The moisture content decreased in the process of milling regardless of the use abrasive rice milling machine.

Magnetic Abrasive Polishing for Internal Face of Seamless Stainless Steel Tube Using Sludge Abrasive Grain (슬러지 연마입자를 이용한 이음매 없는 스테인리스강 튜브내면의 자기연마)

  • Kim, Hee-Nam;Yun, Yeo-Kwon;Kim, Sang-Baek;Choi, Hee-Sung
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.12 no.6
    • /
    • pp.151-157
    • /
    • 2004
  • In this paper deals with behavior of the magnetic abrasive using sludge on polishing characteristics in a new internal finishing of seamless stainless steel tube applying magnetic abrasive polishing. The magnetic abrasive using sludge-abrasive grain WA and GC used to resin bond fabricated low temperature. And sludge of magnetic abrasive powder fabricated that sludge was crused into 200 mesh. The previous research have made an experiment in the static state the movement of magnetic abrasive grain is nevertheless in the dynamic state. In this paper, We could have investigated into the changes of the movement of magnetic abrasive grain. In reference to this result, we could have made the experiment which is set under the condition of the magnetic flux density, polishing velocity according to the form of magnetic brush.

Magnetic Abrasive Deburring Character Analysis According to the powders (Powder의 특성에 따른 Magnetic Abrasive Deburring 특성분석)

  • ;;Yuri M. Baron;Vladimir S. Polyshuk
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • /
    • pp.1877-1880
    • /
    • 2003
  • We were interest in Deburring using MAF(magnetic abrasive finishing) method. So Magnetic inductor was designed and manufactured to generate proper magnetic induction fer deburring the burr formed in drilling SM45C. We experienced according to the Rotational speed, table feed rate, grain size of powder and working gap are changed to investigate the effect on deburring. At this time we experienced in abrasive effect mainly.

  • PDF

A Study on Magnetic Abrasive (자기 연마재에 관한 연구)

  • Kim, Hee-Nam
    • Journal of the Korea Society of Die & Mold Engineering
    • /
    • v.2 no.4
    • /
    • pp.44-47
    • /
    • 2008
  • The magnetic polishing is the useful method to finish some machinery fabrications by using magnetic power. This method is one of the precision techniques and has an aim for clean technology in the transportation of the pure gas in the clean pipes. The magnetic abrasive polishing method is not so common in the field of machine that it is not known to widely. There are rarely researcher in this field because of non-effectiveness of magnetic abrasive. Therefore, in this paper we deals with the development of the magnetic abrasive with the use of Sr-Ferrite. In this development, abrasive grain A has been made by using the resin bond fabricated at low temperature. And magnetic abrasive powder was fabricated from the Sr-Ferrite which was crushed into 200 mesh. The XRD analysis result shows that only A abrasive and Sr-Ferrite crystal peaks were detected, explaining that resin bond was not any more to contribute chemical reaction. From SEM analysis, we found that A abrasive and Sr-Ferrite were strongly bonding with each other.

  • PDF

Development of The Magnetic Abrasive Using Barium Ferrite (Ba-Ferrite를 이용한 자기 연마재 개발)

  • 김희남;송승기;정윤중;윤여권;김희원;조상원;심재환
    • Journal of the Korean Society of Safety
    • /
    • v.18 no.2
    • /
    • pp.46-49
    • /
    • 2003
  • The magnetic polishing is the useful method to finish some machinery fabrications by using magnetic power. This method is one of the precision techniques and has m aim for clean technology in the transportation of the pure gas in the clean pipes. The magnetic abrasive polishing method is not so common in the field of machine that it is not known to widely. There are rarely researcher in this field because of non-effectiveness of magnetic abrasive. Therefore, in this paper we deals with the development of the magnetic abrasive with the use of Ba-Ferrite. In this development, abrasive grain WA has been made by using the min bond fabricated at low temperature. And magnetic abrasive powder was fabricated from the Ba-Ferrite which was crushed into 200 mesh. The XRD analysis result shows that only WA abrasive and Ba-Ferrite crystal peaks were detected, explaining that resin bond was not any more to contribute chemical reaction. From SEM analysis, we found that WA abrasive and Ba-Ferrite were strongly bonding with each other.

A Study on Magnetic Abrasive (자기 연마재에 관한 연구)

  • Kim, Hee-Nam
    • Journal of the Speleological Society of Korea
    • /
    • no.81
    • /
    • pp.1-5
    • /
    • 2007
  • The magnetic polishing is the useful method to finish some machinery fabrications by using magnetic power This method is one of the precision techniques and has an aim for clean technology in the transportation of the pure gas in the clean pipes. The magnetic abrasive polishing method is not so common in the field of machine that it is not known to widely. There are rarely researcher in this feilld because of non-effectiveness of magnetic abrasive. Therefore, in this paper we deals with the development of the magnetic abrasive with the fse of Sr-Ferrite. In this development, abrasive grain A has been made by using the resin bond fabricated at low temperature. And magnetic abrasive powder was fabricated from the Sr-Ferrite which was crushed into 200 mesh. The XRD analysis result shows that only A abrasive and Sr-Ferrite crystal peaks were detected, explaining that resin bond was not any more to contribute chemical reaction. From SEM analysis, we found that A abrasive and Sr-Ferrite were strongly bonding with each other.

A Study on Magnetic Abrasive Using Sr-Ferrite (Sr-Ferrite를 이용한 자기 연마재에 관한 연구)

  • Kim, Hee-Nam;Kim, Dong-Wook
    • Journal of the Speleological Society of Korea
    • /
    • no.79
    • /
    • pp.77-81
    • /
    • 2007
  • In this paper deals with behavior of the magnetic abrasive using Sr-Ferrite on polishing charateristiccs in a internal finishing of staninless steel pipe a tying magnetic abrasive polishing. The magnetic polishing is the useful method to finish some machinery fabrications by using magnetic power. This method is one of the precision techniques and has in aim for clean technology in the transportation of the pure gas in the clean pipes. The magnetic abrasive polishing method is not so common in the field of machine that it is not known to widely. There are rarely researcher in this field because of non-effectiveness of magnetic abrasive. Therefore, in this paper we deals with the development of the magnetic abrasive with the use of Sr-Ferrite. In this development, abrasive grain SiC has been made by using the resin bond fabricated at low temperature. And magnetic abrasive powder was fabricated from the Sr-Ferrite which was crushed into 200 mesh. The XRD analysis result shows that only SiC abrasive and Sr-Ferrite crystal peaks were detected, explaining that resin bond was not any more to contribute chemical reaction. From MACRO analysis, we found that SiC abrasive and Sr-Ferrite were strongly bonding with each other.

Study on the Improvement of Milling Recovery and Performance (IV) -Rice Whitening Performance of the Combined Abrasive- and Friction-type Whiteners- (도정수율(搗精收率)과 성능향상(性能向上)을 위(爲)한 연구(硏究)(IV) -연삭(硏削)·마찰(磨擦)의 조합식(組合式) 정백작용(精白作用)이 정백성능(精白性能)에 미치는 영향(影響)-)

  • Kim, Sam Do;Chung, Chang Joo;Noh, Sang Ha
    • Journal of Biosystems Engineering
    • /
    • v.7 no.2
    • /
    • pp.72-85
    • /
    • 1983
  • Rice whitening is performed by basically two different whitening actions known as abrasive and frictional. The former adopted in the emery stone abrasive type whiteners and the latter in the jet-air friction type. Comparative milling yields and whitening efficiencies between the whitening system consisting of jet-air friction type whiteners only and the system consisting of both abrasive- and jet-air friction-types have not yet been rigorously defined. This study was to examine the effect of combined operations of abrasive- and jet-air friction-type rice whiteners on milling yields and whitening efficiencies. The small capacity commercial units of the abrasive- and friction-type whiteners were used for the experiments. The combinations of whitening treatments were: 1) Once in the abrasive type and then two to three times in the friction type, 2) twice in the abrasive and then two to three times in the friction type and 3) three to five times in friction type. In these tests, counter pressures for the friction type whiteners were established differently as required to get about the same degree of whitening at the end of predetermined numbers of the repeated operations. The speed of emery stone and the slot angle of the screen were also the factors varied in the abrasive type whitener. Sheukwang rice variety having 13.05% M.C. was used in the tests. The dependent variables were the milled- and head-rice recoveries and electricity consumption. The results of the study are summarized as follows: 1. It was found that in the whitening systems consisting of abrasive- and friction-type whiteners slot angle of the screen, the rotational speed of emery stone roller had significant effect on the milling yields and whitening efficiency. In general, the increase of the emery stone roller speed from 690 to 950 rpm presented a positive effect on milling yield, and one-pass abrasive milling combinations had higher milling yields than two-pass abrasive milling combinations. 2. It was apparent that if the slot angle of the screen and the speed of emery stone roller are modified and set at an optimum level, the combination whitening system consisting of abrasive- and friction-type whiteners is better than the pure frictional whitening system consisting of jet-air friction type in terms of milling yields and efficiencies. 3. In the rice whitening system consisting of abrasive- and jet-air friction-type whiteners, the best whitening performance was obtained when the slot angle of the screen and the rotational speed of emery stone roller were $45^{\circ}$ and 950rpm, respectively, for the one-pass abrasive milling combinations. However, for the two-pass abrasive mi11ing combinations, the best performance was obtained with $75^{\circ}$ of slot angle and 950 rpm of the emery stone roller speed. 4. As compared with pure frictional whitening systems, the combination systems produced more milled rice by 0.8-1.0% point and more head rice by 0.5-1.5% point, and consumed less electricity by 0.15-0.20 KwH per 100kg of milled rice when the abrasive whiteners were operated in the modified conditions as described in item 3 above. Further study is recommended to find out optimum operational and design conditions of abrasive type whiterners.

  • PDF

Lateral Crack in Abrasive Wear of Brittle Solids (취성소재 연삭마멸에서의 측면균열에 관한 연구)

  • 안유민;박상신;최상현
    • Tribology and Lubricants
    • /
    • v.15 no.1
    • /
    • pp.46-51
    • /
    • 1999
  • An analytical model about lateral crack occurring in abrasive wear of brittle solids is developed. Stress field around the lateral crack and stress intensity factor at the crack tip are analytically modeled. Abrasive wear by abrasive particle is experimentally studied. In soda-lime glass, it is observed that chipping by lateral crack occurs and produces the greatest material removal when normal load applied by the abrasive particle is about 1.5∼3.0 N. The prediction of lateral crack length from the model is compared with the experimentally measured length in soda-lime glass.