Common mixing process problemsinput time：2017-06-28 hits：26

First, poor fludity of the powder is not easy to mix,

1. The question is raised

In practice, we often encounter very poor flow of powder, according to the observation, piling powder angle ≥ 40 ° of the powder, it is very difficult to mix evenly. It is almost impossible to achieve the goal of homogenous mixing by means of mixing equipment that is operated only by the bucket and it is also very difficult to prolong the mixing time.

2. Solution

Due to the poor fluidity, the powder particles are not easily separated from the surrounding particles. Therefore, it is necessary to have a forceful stirring method during mixing to repeatedly cut and displace the powder particles so as to overcome the difficulty of mixing due to poor fluidity.

Therefore, the mixing of poor liquidity of the powder, the mixing equipment to be selected with mixing blades in the mixer, in order to better complete the mixing task.

Second, light weight powder is not easy to mix the problem

1. The question is raised:

For example, in the seasoning mix should be relatively heavy salt and lighter paprika, dry onion and other mixed, is a typical mixture of light and heavy powder. Through the movement of liquid powder liquid model shows that the powder in the movement of the mixing container, as thin and light paprika, the proportion of dried onion is much smaller than the salt, MSG and other powder, it has been floating in the top of the container, Without coercion, they remain difficult to mix into the body powder even when mixed for long periods of time.

2. Solution

1) The use of dual-motion mixer to solve this problem, (as shown below) As the double-motion mixer container rotation and internal blade rotation in the same direction (speed is not the same), so that the container and the leaves will be co-floating The light powder above enters the main heavy powder so that the light and heavy powder can be uniformly mixed.

2) According to the composite index, calculation and analysis indicate that the heavy powder index such as salt and monosodium glutamate is too large, and the composite index is close, that is, the specific gravity, the average particle size The smaller the equilibrium value is, the closer it is to paprika and dried green onion, thus reducing the difficulty of the mixing process. Just the cost of doing so is not economically cost-effective.

Third, ultra-fine powder is not easy to mix the problem

1. The question is raised

Ultrafine powder usually refers to more than 1000 mesh or more than 2000 mesh powder, the analysis of a designated powder, when the average particle size is small to a certain extent, its external physical characteristics will be a huge change, the original Floating will not float will change, and there will be adsorption, Baotuan other characteristics, especially for such ultra-fine powder mixed even more difficult.

This is mainly due to the fact that the original gravitational bondage to the particles has become insignificant when the particles are refined into fine powders. There is no gravity to constrain its motor activity, electrostatic effects will highlight, to the mixing process is difficult.

2. Solution

1) Reduce the speed of mixing equipment, try to avoid the floating movement of ultra-fine powder. As far as possible for mixing equipment, low-speed operation, reduce the activity of ultrafine powder.

2) The selection of dual-motion mixing equipment, the use of its co-movement with the container has a coercive force with the leaves, floating in the container above the ultrafine powder pressed into the main powder, thus solving this problem.

When loading, the material is loaded into the mixer container 80% -85%, much more is installed in order to reduce the possibility of ultrafine powder floating, increasing the pressure between the powder is conducive to the effect of blade shear.

Fourth, add trace elements difficult to mix the powder difficult problem

1. The question is raised

In the food, additives, pharmaceutical and other industries, the product often need to add trace elements, these trace elements involved in mixing the following difficulties:

1) The addition of trace elements is small, and sometimes only 1 ‰, or even less; trace elements are also particularly valuable and important, play a key role in product quality, therefore, once the accumulation of trace elements in the bucket dead ends, it will result in product scrap .

2) Generally, the main powder of foodstuffs, additives, pharmaceuticals and other industries has poor fluidity, which brings great difficulties to the uniform mixing of a very small amount of trace elements.

2. Solution

For the above difficulties can be used to solve the following methods:

1) Adopt gradual increment mixed method to solve, keep diluting trace element, achieve the purpose of its even mixing. For example, in a mixed task with a trace element content of 1 ‰, the task can be divided into three times, each time in a 1:10 ratio, and finally the mixing task is completed. This method of operation time-consuming, laborious, many links and error-prone.

2) Aiming at the difficulty of accumulating trace elements in the corner of the bucket, a mixing device that can move the bucket should be adopted, so that dead spots can be avoided and accumulation of trace elements in the dead zone can be avoided.

3) Aiming at the difficulty of adding trace elements and poor fluidity of the main powder, a mixing device with a forced shearing stirring function needs to be adopted so as to overcome the difficulties of poor powder flowability, and at the same time, Cut the trace elements, make it mass evenly, to achieve the purpose of uniform mixing of trace elements.

3. Add the mixture of trace elements powder

Thus it can be seen that only mixing equipment with two mixing modes can perfectly solve the problem of powder mixing with the addition of trace elements, so as to simplify the operation procedure and mix in one time.

Fifth, the existence of false particles in the powder is not easy to mix the problem

1. The question is raised

Fake particles is formed by the small particles hold the ball between the larger groups of particles - that is, as fake particles. The formation of fake particles for a variety of reasons, such as wet board junction, electrostatic adsorption, due to the processing of high temperature adhesion and so on. If you do not open the fake particles when the powder is mixed, it will affect the mixing effect and thus the quality of the final product. To avoid the appearance of fake particles, it is necessary to have a shear force that can open and break up the adhesion between the fines during mixing. While a single bucket moving mixing device can not provide such a shear force during mixing, it can do nothing to fake particles.

2. Solution

Double-motion mixer with full-size blades to do interspersed, shear movement, can be a good fake particles open, break up, to achieve better mixing effect. However, if the fake particle's adhesion is too strong, too "stubborn", double motion mixer can not completely break it up, then need to help with other equipment.

LAST：