各类粉体混合机粉体均化评测
Powder mixing is a process of uniform distribution of particles of different physical and chemical properties through mechanical or fluid methods. In short, the inhomogeneity of two or more solid powder materials is reduced to the lowest under the action of external force. With the rapid development of new materials and industrialization, the homogeneous mixing of powder composites becomes more and more important.
一、粉体混合定义及混合机理
One, mixing definition and mixing mechanism of powder
(一)粉料混合定义
(1) mixing definition of powder
粉体混合是指将两种或两种以上的不同成分的粉体混合均匀的过程。混合也是制备产品整个过程的第一步,混合物各组分质量的分布均匀至关重要,因为混料不均匀在后续工艺中是无法调整的。
Powder mixing refers to the process of mixing two or more than two different components of the powder evenly. Mixing is also the first step in the whole process of preparing the product. The distribution of the components of the mixture is very important, because the unevenness of the mixture can not be adjusted in the subsequent process.
粉体混合形式分类
Classification of mixed forms of powder
(2)混合机理
(2) mixing mechanism
粉体混合机理是粉体颗粒间相互扩散、对流、剪切,目前常用的混合方法有:三维混合,双锥混合、球磨混合及先进的双运动混合。双运动混合是利用料桶的转动和料桶内部叶片的转动(转动速度是料桶转动速度的2倍)同时强制驱动粉体相互扩散、对流、剪切,形成复杂的运动,从而达到理想的混合效果。
The mixing mechanism of powder is the diffusion, convection and shear between particles. The common mixing methods are three dimensional mixing, double cone mixing, ball milling mixing and advanced double motion mixing. The double motion mixing is to make use of the rotation of the barrel and the rotation of the inner blade of the barrel (2 times the rotation speed of the barrel), and force the powder to spread, convective and shear, and form a complex motion, so as to achieve the ideal mixing effect.
二、影响粉体混合均化工艺的因素
Two. Factors affecting the homogenization process of powder mixing
(一)颗粒大小
(1) particle size
粗大的粉体颗粒具有较好的压缩性,但成形性差;细小粉体颗粒成形性好,但压缩性差,因此大小颗粒适当的搭配,能改善粉体的填充型,提高粉体的压缩性和改善粉体的烧结性能。但是,粉体颗粒大小差异越大,越不易混合。细粉体易“搭桥”和相互黏附,妨碍颗粒的相互移动,不易均匀分散。
The coarse powder particles have good compressibility, but the formability is poor, the fine particle size is good, but the compressibility is poor, so the proper matching of the particles can improve the filling type of the powder, improve the compressibility of the powder and improve the sintering properties of the powder. However, the larger the particle size difference is, the less likely it is to mix. Fine powders are easy to bridge and adhere to each other, which impede the movement of particles and are not easy to disperse evenly.
(二)松装密度(比重)
(two) the density of the loose assembly (specific gravity)
松装密度差异越大,越不容易混合。松装密度小的轻粉易漂浮,混合时,始终漂浮于上方,很难混入较重粉的组元里,不易混合均匀。
The bigger the density difference is, the less easy it is to mix. The lightweight powder with small bulk density is easy to float. When mixing, it always floats above, so it is difficult to mix with the heavier powder components and difficult to mix evenly.
(三)流动性
(three) liquidity
粉体流动性差,颗粒间相互粘附,不利于粉体相互穿插移动、对流,不易于其他粉体混合均匀。
The powders have poor fluidity and adhere to each other, which is not conducive to the interpenetration and convection of powders, and is not easy to mix well with other powders.
(四)粉体性质
(four) the properties of powder
颗粒性质包括:粒子的粒度与粒度的分布,粒子的形状、粗糙度,粒子的密度、静电荷、水分含量、脆碎性、休止角、流动性、结团性以及弹性等。例如:粒子的形状影响粒子的流动性,粒子的密度差异在混合中会发生密度偏析作用。
The particle properties include particle size and particle size distribution, particle shape, roughness, particle density, static charge, moisture content, fragility, repose angle, fluidity, mass and elasticity, etc. For example, the shape of particles affects the fluidity of particles, and the density difference of particles will result in density segregation.
三、常用的粉体混料机介绍
Three, introduction of common powder mixing machine
目前,常用的粉体混料机主要有:三维混合机、V型混合机、双锥混合机。
At present, the commonly used powder mixer is mainly composed of three dimensional mixer, V mixer and double cone mixer.
(一)三维混合机
(I) three dimensional mixer
工作原理:装料的桶体是在主动轴的带动下,作周而复始的平移转动和翻滚等复合运动,促使物料沿着桶体作环向、径向和轴向的三向复合运动,从而实现多种物料的相互流动、扩散、积聚、掺杂,达到均匀混合的目的。
The working principle: the barrel body of the material is driven by the active axis, and makes the complex movement of moving and rolling round and rolling around, making the material move along the barrel body as the ring, radial and axial three direction compound movement, so as to realize the mutual flow, diffusion, accumulation and mixing of various materials, and achieve the purpose of uniform mixing.
三干粉混合机优点:料桶内不存物料死角。
Three the advantage of dry powder mixer is that there is no material dead angle in the barrel.
缺点是:装载率低,一般不超过60%;对于超轻粉、超细粉不易混合均匀,容易漂浮料桶上方,微观上难以达到颗粒与颗粒之间充分均匀混合。
The disadvantage is: low loading rate, generally not more than 60%; for ultra light powder, ultrafine powder is not easy to mix evenly, easy to float on the top of the barrel, it is difficult to achieve a full and uniform mixing between particles and particles on the micro.
(二)干粉混合机
(two) dry powder mixer
工作原理:利用混料机二圆柱桶长度不相等,行成不对称的原理,当混料机转动时物料从分解到组合,从组合到分解,推动物料进行横向交流,每转动一圈横向力使部分物料从一个桶流向另一个桶,这样物料横向径向混和,分解组合相互进行,使物料达到均匀的混合效果。
Working principle: using the two cylinder barrel length is not equal, the principle of asymmetrical line, when the mixing machine rotates the material from decomposition to combination, from combination to decomposition, to promote the material transversal communication, each rotation one circle of lateral force to make part material from one barrel to another, so that the material crosswise radial mixing, decomposition group Combined with each other, the material can achieve a uniform mixing effect.
V型混合机优点:当混合流动性好、物性相近似的混合物料时,可以得到较好的混合效果。
The advantages of the V mixer are that when mixed materials with good fluidity and similar physical properties are obtained, a better mixing effect can be obtained.
缺点是:当混合粉体物料物性差距较大时,一般不能得到理想的混合物;能耗较大大;颗粒间相互冲击、摩擦较大,易改变粉体组元的基本特性,如:粒度变小,颗粒形状改变。
The disadvantages are: when the material property gap is large, the ideal mixture can not be obtained; the energy consumption is much higher; the intergranular impact and the friction are large, which can easily change the basic characteristics of the powder component, such as the size of the particle and the shape of the particles.
(三)双锥混合机
(three) double cone mixer
工作原理:将粉体加入到双锥料桶中,随着料桶的不断旋转,粉体物料在容器中进行复杂的撞击运动,达到均匀的混合。
Working principle: the powder is added to the biconical barrel, and with the continuous rotation of the barrel, the powder material has a complex impact movement in the container to achieve a uniform mixing.
双锥混合机优点:可以实现粉体间快速混合。
The advantages of double cone mixer are: quick mixing between powders.
缺点是:转速过慢时,物料容易分层滚动,无法快速有效的掺入混合,而且容易形成球形结团粒。
The disadvantages are: when the rotational speed is too slow, the material is easy to roll in layers, can not mix quickly and effectively, and easy to form spherical agglomeration.
四、不同类型混合机应用领域
Four. Application fields of different types of mixers
(一)三维混合机
(I) three dimensional mixer
三维混合机广泛应用于医药、化工、食品、饲料、农药等行业。不仅适用于普通粉体物料的混合,还应用于含油多、含糖多、粘度大、易燃、易爆、升温固化、升温软化物料的混合。如药物、粉体涂料(预混合及成品混合)、流平剂、食品加剂等,并可以和生产线配用。
Three dimensional mixer is widely used in medicine, chemical industry, food, feed, pesticide and other industries. It is not only suitable for the mixing of ordinary powder material, but also used in the mixture of oil containing more, more sugar, large viscosity, flammable, explosive, heating and curing, heating softening material. Such as drugs, powder coatings (premix and finished products mixed), leveling agent, food additives, etc., and can be used with the production line.
(二)V型混合机
(two) V type mixer
V型混合机适用于两种以上干粉状、颗粒状粉体物料的混合,尤其对微量的添加剂也可达到良好的混合效果,广泛使用于制药、化工、食品、塑料、化妆品、陶瓷、冶金等领域。
V mixer is suitable for mixing more than two kinds of dry powder and granular material, especially for small amount of additives. It is widely used in the fields of pharmaceutical, chemical, food, plastic, cosmetics, ceramics, metallurgy and so on.
(三)锥型混合机
(three) conical mixer
锥形混合机适用于固体与固体、固体与液体、液体与液体混合,广泛用于化工、染料、石油、冶金、建材、稀土等领域。锥形混合机对热敏性
The conical mixer is suitable for mixing solid and solid, solid and liquid, liquid and liquid. It is widely used in chemical industry, dye, petroleum, metallurgy, building materials, rare earth and other fields. Thermal sensitivity of conical mixer
国内某大型多品种氧化铝企业的原料均化系统
Raw material homogenization system for a large variety of alumina enterprises in China
对于该大型原料均化系统,专业^认为:
For the large-scale raw material homogenization system, professional experts believe that:
氧化铝粉体加工过程采用均化也是借鉴了国外的先进经验,日本昭和30年前就已经在工业化应用。原料均化目的是保证生产配料和工艺的稳定性,严格来说出厂产品都应该保证品质的均匀稳定,同类规格产品无论当期批次,还是不同时期的,都应质量保证一致。粉体原材料对一致性要求甚至大于产品性质本身。
Homogenization of alumina powder is also a reference to the advanced experience of foreign countries, Japan Zhao and 30 years ago has been in industrial application. The purpose of raw material homogenization is to ensure the stability of the production of ingredients and processes. Strictly speaking, the products of the factory should ensure the uniform stability of the quality. The quality assurance of the products of the same specification should be consistent with the quality assurance, whether in the current period or in different periods. The consistency requirement of powder material is even greater than that of the product itself.
该大型均化系统一般工作原理是把不同时期和不同供应商的原料放入不同储罐里,通过皮带称多点计量下料,混合添加矿化剂。产品出来后的均化,昭和做法就是把不同产品先分类储存在立罐里,然后多点计量下料,气动混合。
The general principle of the large-scale homogenization system is to put the raw materials in different periods and different suppliers into different storage tanks, measure the material by weighing the multi point on the belt and add the mineralizer. Homogenization after the product comes out, Zhaohe approach is to classify the different products stored in a can, and then multi-point measurement of cutting, pneumatic mixing.