What kind of damage will the quality of the conveyor belt cause to the conveyor

Basic Description

The reduction of the safety factor of the conveyor belt not only saves investment costs, but also has far-reaching significance for the design of the mechanical parts of the conveyor.

1, the current standard conveyor belt safety factor regulations

The national standard "Belt Conveyor Engineering Design Code" GB50431-2008 stipulates the safety factor of the conveyor belt:

(1) The safety factor of fabric core conveyor belt, and the safety factor of cotton fabric core, preferably 8-9;

(2) Nylon, polyester fabric core conveyor belt, preferably 10-12;

(3) The safety factor of the steel cord conveyor belt can be 7-9; when the belt conveyor is controlled by soft start and braking measures, it can be 5-7.

This specification breaks through the limit of "the minimum safety factor of steel cord conveyor belt is 7" in the previous standards of our country.

2. The necessity and basis for reducing the safety factor of the conveyor belt

(1) The importance and necessity of reducing the safety factor of the conveyor belt

conveyor belts, especially high-strength conveyor belts, account for up to 30-50% of the investment in belt conveyors. To choose conveyor belts reasonably and reduce the investment of conveyor belts, an important way is to improve the joint technology of conveyor belts in order to reduce the safety factor.

(2) Foreign and domestic regulations and existing problems

The German Industrial Standard DIN22101-1982 on the safety factor of the steel cord conveyor belt is defined as the ratio of the tensile strength of the steel cord conveyor belt to the conveyor belt tension when the conveyor is running stably, with a minimum of 6.7. In 2002, Germany revised the original 1982 standard, and the new version adopted a brand-new concept and calculation method. The conclusion is that the safety factor of steel cord conveyor belt can be less than 6.7, and the lowest can be 4.5. In the past ten years, some foreign countries have already broken through the 1982 regulations. The belt conveyors in operation in Germany, Britain, New England, Australia and other countries have adopted 4.5-5.5. According to the research results of foreign institutions such as the United States CDI Company, the safety factor of the steel cord conveyor belt can be reduced to below 5.5, which can be 4.5 to 5.0.

(3) The feasibility of adjusting the safety factor of conveyor belts in my country

Since my country's serialization in the 1980s, the value of the safety factor has been gradually decreasing. China’s conveyor belt manufacturing technology has approached or reached the international advanced level; conveyor belt joint technical parameters and joint strength grades have adopted the current German industrial standards, conveyor belt joint vulcanization technology has become more mature, and the vulcanization equipment manufacturing technology and vulcanization joint technology level Improved to meet the requirements of joint strength; China's belt conveyor drive system has widely adopted mature soft-start technology; long-distance, complex belt conveyors have generally adopted more reliable frequency conversion technology or other controllable soft-start systems , The driving tension multiple of the conveyor belt can be controlled below 1.2.

After the above and the provisions in the standard: the safety factor of the conveyor belt should be selected according to different conditions: that is, the safety factor of the general belt conveyor and the steel cord conveyor belt can be 7-9; when the conveyor is controlled by soft start and control When moving measures, 5-7 can be taken.

3. Several issues that should be paid attention to when reducing the safety factor

(1) Special types of conveyor belt joint methods should be implemented in accordance with the corresponding regulations.

(2) For large and important belt conveyor belt joints, technical requirements should be indicated in the design documents, and joint strength tests should be carried out before construction.

(3) Large and important belt conveyors, such as lifting systems or belt conveyors with a higher lifting height, or some important conveyor belt joints of different manufacturers and batches, and regular image inspections if necessary.