Pages

January 30, 2019

Thermal phenomenon and analysis of grinding machine’s milling roller

by Wu Wenbin, Henan University of Technology, China

Wheat is the world's largest food crop, and the global demand for wheat flour is large every year. The milling industry has become an important basic industry in the global food industry. Roller mills are also growing more common as flour production equipment on the market, and they are the core and key equipment for all varieties of milling processes.

 


The grinding roller is the heart of the roller mill, and its performance directly affects and determines the quality and taste of the flour. However, there are some problems that can arise in the production process, mainly due to the shearing, extrusion, and friction between the grinding roller and the material, as well as the difference in technical parameters such as the rotational speed, the rolling distance and the speed ratio of the grinding roller.

When there is a large pressing force between two rollers, the pressing and rubbing of the material by the grinding roller causes a large amount of frictional heat between the roller and the material. The heat of friction generation is mainly related to the speed difference of the fast and slow rolls, the roll diameter, the roll length, the rolling distance, and the pressure between the rolls. At the same time, in the non-steady state, due to the deformation heat, friction heat and heat conduction of the material, the grinding roller continuously absorbs heat from the roller surface during the rotation process, causing the surface temperature of the grinding roller to gradually rise and for heat to transfer to the inside of the grinding roller, causing grinding. There is a large amount of heat accumulation inside the roller.

The start-up performance and isothermal performance of the mill are an important indicator to measure the performance of the mill's grinding roller. The uniformity of the roller surface temperature can greatly affect the quality and taste of the flour. The heat absorption section of the grinding roller is mainly based on heat conduction and obeys the Fourier heat conduction law.

The heat dissipation section is mainly composed of convective heat transfer and radiation heat transfer in a limited space. The success of the start-up performance mainly depends on the assembly quality of the grinding roller of the mill, and the isothermal performance primarily depends on the temperature uniformity of the roll surface during the working process.


Read more HERE.
 

The Global Miller
This blog is maintained by The Global Miller staff and is supported by the magazine Milling and Grain
which is published by Perendale Publishers Limited.


For additional daily news from milling around the world: global-milling.com

No comments:

Post a Comment