农业工程学报
農業工程學報
농업공정학보
2013年
1期
56-63
,共8页
张琴%丁为民%邓丽君%李毅念%赵亚平
張琴%丁為民%鄧麗君%李毅唸%趙亞平
장금%정위민%산려군%리의념%조아평
摩擦%试验%农产品%芡实%内摩擦系数%静滚动稳定角%休止角
摩抆%試驗%農產品%芡實%內摩抆繫數%靜滾動穩定角%休止角
마찰%시험%농산품%검실%내마찰계수%정곤동은정각%휴지각
friction%experiments%agricultural products%gorgon nut%inner friction coefficient%static roll stable angle%angle of repose
为给芡实脱壳后的分离工艺和机械设计提供相关的物料性能数据,利用剪切仪、自制的斜面仪、休止角测定装置等设备,对不同成熟度、不同粒径大小的芡实颗粒的内摩擦系数、静滚动稳定角、休止角等摩擦特性进行了测定.结果表明,芡实颗粒越小、成熟度越低、接触表面粗糙度越大,则颗粒之间的摩擦力越大、颗粒与接触材料的摩擦力越大,其内摩擦系数、静滚动稳定角、休止角越大;利用斜度14.7~21.5°的斜面仪能够分离出芡壳,但不能对芡仁和带壳芡实整粒进行有效分离;采用橡胶板分离芡壳、芡仁效果最好.研究结果可为芡实脱壳、分离等相关机械的研发提供参考.
為給芡實脫殼後的分離工藝和機械設計提供相關的物料性能數據,利用剪切儀、自製的斜麵儀、休止角測定裝置等設備,對不同成熟度、不同粒徑大小的芡實顆粒的內摩抆繫數、靜滾動穩定角、休止角等摩抆特性進行瞭測定.結果錶明,芡實顆粒越小、成熟度越低、接觸錶麵粗糙度越大,則顆粒之間的摩抆力越大、顆粒與接觸材料的摩抆力越大,其內摩抆繫數、靜滾動穩定角、休止角越大;利用斜度14.7~21.5°的斜麵儀能夠分離齣芡殼,但不能對芡仁和帶殼芡實整粒進行有效分離;採用橡膠闆分離芡殼、芡仁效果最好.研究結果可為芡實脫殼、分離等相關機械的研髮提供參攷.
위급검실탈각후적분리공예화궤계설계제공상관적물료성능수거,이용전절의、자제적사면의、휴지각측정장치등설비,대불동성숙도、불동립경대소적검실과립적내마찰계수、정곤동은정각、휴지각등마찰특성진행료측정.결과표명,검실과립월소、성숙도월저、접촉표면조조도월대,칙과립지간적마찰력월대、과립여접촉재료적마찰력월대,기내마찰계수、정곤동은정각、휴지각월대;이용사도14.7~21.5°적사면의능구분리출검각,단불능대검인화대각검실정립진행유효분리;채용상효판분리검각、검인효과최호.연구결과가위검실탈각、분리등상관궤계적연발제공삼고.
Gorgon nut is a local special agricultural and sideline product rich in nutrients and with high economic value. However, the lack of machinery related to production, processing of gorgon nut has seriously held back the development of the gorgon nut industry. Experimental study on gorgon nut friction characteristics can provide a theoretical basis for its peel, separation and other related machinery researches and development. Parameters like inner friction coefficient, static roll stable angle and angle of repose are measured on gorgon nuts with equipments including shear apparatus, self-made bevel instrument and angle of repose measuring device. Friction characteristics are analyzed on gorgon nuts of different maturity levels, particle diameters and surface roughness. It is demonstrated that, smaller particle diameter results in more particles per unit area of inner contact and thus larger mosaic force of engagement between the concave and convex surface of particles, which also leads to higher friction resistance and increased inner friction coefficient. It is also showed that, under the same measurement conditions, inner friction coefficient was decreased with the increase of maturity level of gorgon nuts.
@@@@When measuring static roll stable angles using bevel instrument, put a single gorgon nut on the inclined plane, then turn the handle slowly to gradually increase the plane inclination. When the gorgon nut just starts to roll down, measure the inclination immediately using protractor instrument. The measured value is then used as the static roll stable angle. Static roll stable angles of gorgon shells are significantly bigger than gorgon jens and gorgon nuts with shell. But the difference is smaller between gorgon jens and gorgon nuts with shell (difference of 0.1°-2.4°for medium maturity gorgon nuts). Gorgon shells can be separated from gorgon jens by bevel instrument with inclined plane of 14.7°-21.5°gradient, which cannot be used for efficient separation of gorgon nuts with shell and gorgon jens.
@@@@It is also observed that using different plates (e.g rubber plate, unpolished wood and stainless steel plate) can result in different efficiency in separation of gorgon shells, gorgon jens and gorgon nuts with shell. For gorgon nuts of medium maturity, rubber plate is the best way for separation of gorgon shells and gorgon jens due to the biggest difference (16.9°-18.5°) in static roll stable angles. On the other hand, with a difference of 12.3°-14.1°in static roll stable angles between shells and jens, stainless steel plate is least effective in separation of the two. For all the three plates, there is no significant difference (0.1°-2.4°) in static roll stable angles between jens and nuts with shell; thus none of the plates can be used for efficient separation of jens and nuts with shell.
@@@@For all the three plates, repose angle of gorgon nuts was decreased with the increase of particle diameter. Under the same measurement conditions, low-maturity gorgon nuts have the biggest repose angle while high maturity gorgon nuts have the smallest and medium-maturity gorgon nuts in the middle. In comparison of repose angle on different plates, for gorgon nuts of different particle size and maturity levels, rubber plate always has the biggest repose angle while stainless steel plate has the smallest.