Study on Automatic Control of Rotary Kiln

AUTHOR: admin DATE: 27 May 2012 06:48:28

Rotary kiln is a large sized thermal machine with the advantages such as high quality of roasting and products so that it plays an important role in many industrial departments such as chemistry, metallurgy and mining. However, this equipment belongs to those kinds of devices that have very high energy consumption in our country. Especially inside the small and medium companies, the automatic level of the production process of the rotary kiln is very low, so that the whole working process of the equipment should be in a high energy consumption station for a very long period of time which will definitely aggravate the tension of the energy resources in our country.

Some large sized mining companies in our country also did some meaning practice in the automatic control aspect of the rotary kiln, mainly by way of examining the thermo technical signals inside the kiln such as temperature, pressure and flow amount of the slurry, on the basis of which, keep the temperature of the burning area in a allowable range with the method of intelligent control. However, because of the limit of the examining means, when designing such control systems, the experts often forget the important information of the moving state of the materials inside the kiln. As a matter of fact, the moving state of the materials has a decisive effect on the energy transmission process of the kiln.

The materials inside the industrial rotary kiln such as aluminum oxide rotary kiln and limestone roasting rotary kiln is mainly in a slumping moving state, and the angle of repose is important information describing its movement features. We simulate the cross section of the rotary kiln with a solid of revolution and adopt the computer image processing technology to follow the sliding process of the materials, and measure the changing relationship of the angle of repose of the materials with time in an offline state and finally get the changing range of the angle of repose. On the basis of which, we analyze the relationship of the avalanche time which is an important parameter that influences the heat transfer process of the kiln and the materials compactness. According to the experiment result, we make a comparison and data validation to the existing Slumping Theoretical model and it shows that the model proposed by Mellmann has a relatively higher precision.

At present, there is still no report on the research of computer online examination of the angle of repose of the materials inside the industrial rotary kiln. Aiming at the characteristics of the complicated image area and low noises of the materials in the kiln, experts of Hongxing Machinery put forward a measurement method of the angle repose of the materials based on the image processing technology. By way of a series of process such as collecting, mean value cluster segmentation of the vague C, fringe collecting and least squares fitting a straight line of the original image of the kiln, we get the angle of repose. In order to validate the feasibility of this method, we did a Matlab computer simulation to the image alignment of an aluminum oxide rotary kiln and get a dynamic curve of the angle of repose with the change of time and the cycle feature of the curve correctly reflects the movement state of the materials inside the kiln.

Henan Hongxing Mining Machinery Co., Ltd is a large-sized sand maker manufacturer, and our sand maker has many advantages such as simple and reasonable structure, high independent impact crushing ability, super low operational cost and the most competitive price.