Material position detecting method and device based on vibration signal of ball grinder rotating cylinder body

Abstract

The invention discloses a material level detecting method and a detection device based on vibration signal of ball mill rotary drum. The invention is characterized in that the method comprises the following procedures: (A) installing a vibration acceleration transducer on the ball mill rotary drum; (B) setting data collection parameters, and calculating a circumferential angle L when the transducer collects a group of data measuring points; (C) determining the circumferential area of the transducer for data collection, and acquiring the relation between the maximum impact point of a steel ball on the ball mill rotary drum and the level; (D) acquiring the impact vibration signal between the steel ball in the drum and the coal, steel ball and steel ball, as well as the steel ball and the drum wall; (E) determining the maximum impact point of the steel ball on the drum; (F) calculating the level value of the ball mill in the state. The detection device comprises a ball mill drum and a vibration accelerator arranged on the ball mill drum. The invention has the advantages of real-time and accurate level detection, and avoidance of influence on measurement results caused by changes of category of coal, water content of coal, particle size of coal and other factors.

Description

technical field [0001] The invention relates to a method for detecting the material level in a ball mill drum, in particular to a material level detection method and a detection device based on the vibration signal of the ball mill rotating drum. Background technique [0002] Drum-type steel ball mill is a common and typical grinding equipment, it is used in metal and non-metallic mineral processing plants, building materials, refractory materials, cement, coal, chemical industry, electric power, light industry and metallurgy and other industries. The most widely used in crushing. In many thermal power plants in my country, the barrel type low-speed ball mill is a commonly used equipment in the pulverizing system. Its function is to dry, crush and grind coal of a certain size into pulverized coal of a certain fineness for boiler combustion. For the intermediate storage pulverizing system, the power consumption of the ball mill is as high as about 20% of the power consumptio...

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Problems solved by technology

[0004] (1) Differential pressure method, using the differential pressure signal at the inlet and outlet of the ball mill drum to indirectly measure the material level in the drum, but because the differential pressure signal is affected by many factors such as material level, ventilation rate, outlet temperature and ball mill structure, it is difficult The function of differential pressure and material level is established, so the measurement accuracy is very limited and unstable

[0005] (2) Useful power method, using the transformation rule between power and material level to detect the material level, which is less affected by the surrounding environment, but there are many factors affecting the power and the sensitivity is not high, especially when the power is reduced, it is difficult to judge

However, because the ultrasonic wave is easily absorbed and attenuated, it is easily affected by the environment such as temperature and steam. At the same time, it requires the space above the material level to be clean. However, the drum is full of dust, which seriously interferes with the reflected wave and cannot accurately detect the material level.

[0009] (6) Weighing method, by installing a strain gauge load cell under the ball mill roller bearing to detect the material level, this method can achieve good results in general industrial environments, but it cannot guarantee long-term reliability in harsh environments Work

[0010] (7) Noise method, according to the use of monitoring noise to judge the material level, but in the actual operation, the change of coal type (especially the change of moisture) will cause a large audio signal error, resulting in a large amount of material level measurement. deviation

These factors themselves influence each other, so that there are still many problems in the above-mentioned detection method, and it is difficult to accurately reflect the material level in the ball mill drum; In the uneconomical area, the power consumption of milling is relatively high; at the same time, it also makes it difficult for the automatic control system of the ball mill to be used reliably for a long time, and the material level still depends on manual operation

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