Do you know the origin and application of wheat mill?

We must remember that this tool, commonly known as a roller, is composed of a wheel and a roller plate. Before the middle of last century, it was a kind of wheat milling tool widely used in the north of China, and it was also the rudiment of the roller mill.

Modern milling machine is to change the plate into a roller, so that the two rollers move towards each other, so as to achieve the effect of crushing wheat. Therefore, the working principle of the mill is to use a pair of grinding rollers with speed difference and relative rotation to strip the wheat, peel the wheat endosperm from the wheat skin and grind it into flour. 

This is the pneumatic roller mill

Roller mill is one of the main equipments necessary for wheat processing. Its development has also gone through several stages, manual, hydraulic and pneumatic mills. Before 1980s, manual and hydraulic mills were widely used in China. A complete set of less than 50 tons/24h capacity use manual mills, more than 60 tons/24h of flour mills use hydraulic mills. The disadvantage of hydraulic mill is: oil leakage, difficult to handle. At the end of 1980s, with the gradual improvement of the quality of pneumatic components in our country, pneumatic mills gradually went to the market, replacing hydraulic mills. For small flour mills, manual mills are still in use.

Mill structure

At present, the roller mill on the market are of compound structure, that is, the whole machine is composed of two independent parts, each part is mainly composed of two grinding rolls (grinding system), two feeding rolls (feeding system) and some auxiliary mechanisms (transmission part).

Inside structure of the roller mill

(1) Feeding part: it is the first part of the wheat mill, which is called the observation tube or feeding box, for the wheat or other wheat products that have been broken in the milling process. This part is generally made of transparent materials, which can easily observe the flow of materials, and facilitate the operator to adjust the mill timely according to the height of its material level; from the intuitive point of view, the feeder box is a box structure of materials entering the wheat mill.

(2) Feeding system (or homogenizing part): it is under the feeding box and on the upper part of the grinding roll, which is generally composed of two cylindrical rolls. According to the different position of each wheat mill in the whole milling process, different rotational speed and speed ratio are designed to make the material distribution more uniform before entering the grinding roller, so as to achieve the uniform thickness of the material entering the grinding roller, so as to ensure the consistent grinding effect.

 

3) Grinding system: refers to grinding roller and some auxiliary parts, such as grinding roller cleaning system, grinding roller baffle, etc. the processing quality of grinding roller itself directly affects the quality and output of flour.

Hongdefa manufacturing workshop for grinding rollers

(1) Transmission part: as we all know, the rotation speed of the grinding roll outside the mill is higher than that inside, so it is used to call the two grinding rolls outside the wheat mill fast roll and the two inside slow roll. A certain speed ratio should be ensured between the two grinding rolls, so a set of transmission mechanism between the grinding rolls (including fast and slow roll pulley, tooth wedge belt, etc.) should be set to meet this requirement; The traditional pneumatic wheat mill is driven by the fast roll or slow roll.

 

 

Process parameters of mill

 

Flour processing is a continuous production process, and wheat mill plays an important role in the whole production line. According to the needs of milling process, the mill is divided into four grinding systems: skin mill (b), core mill (m), slag mill (s) and tail mill (T).

 

The process configuration of each grinding system is different,

 

①　The results show that the process parameters of the surface of the feeding roller are different;

②　 the position of the feeding door is different;

③　the shape parameters of the surface of the grinding roller are different;

④　the gap of the grinding roller is different when the wheat mill is working, that is, the rolling distance is different. The rolling distance is the minimum distance between two grinding roller surfaces;

⑤　 the rotation speed of grinding roller is not the same;

⑥　the speed ratio of grinding roller is not the same;

⑦　 the rotation speed of feeding roller is not the same;

⑧　 the speed ratio of feeding roller is not the same. These parameters related to process position are basically guaranteed by mechanical mechanism design or mechanical parts design.

 

The above discusses the origin and application of modern mill. You are welcome to criticize and correct.