Mine fan quality appraisal

mine fan takes the synergy of efficient ventilation and safety control as its core principle. By optimizing air volume, static pressure efficiency and explosion-proof performance, it realizes the synergy of mine main ventilation, local ventilation and emergency reverse wind. It is widely used in coal mines, metal mines, tunnel engineering and other fields. In gas mines, it is used for rapid dilution of methane/carbon dioxide; in deep mine mining, it meets the ventilation and cooling requirements for high temperature heat damage; in dust prevention and control, it ensures that respiratory dust emissions meet standards. Compared with ordinary fans, mine fans have the characteristics of explosion impact resistance, corrosion resistance and intelligent control, and are the core equipment for safe mine operations.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide mine fan quality appraisal services. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for mine fan quality appraisal.

As mining safety regulations become stricter, related quality dispute cases have increased significantly. The judicial dispute focuses on:

1, performance index dispute: the rated air volume does not meet the standard, and the reverse wind efficiency is low;

2, material defects: insufficient fatigue strength of the blade aluminum alloy, impact resistance of the explosion-proof shell Poor;

3, process problems: cracks in welding joints, harmonic distortion rate of frequency converters;

4, contract performance disputes: core modules (such as intelligent monitoring sensors, redundant power systems) are inconsistent with the technical agreement.

The litigation quality appraisal of mine fans generally follows the following technical methods:

1. Appearance inspection: Check whether the fan casing, impeller, motor and other components have defects such as deformation, damage, corrosion, etc., and record relevant dimensions, weight and other parameters.

2. Performance test: Conduct air volume test, wind pressure test and power test on the fan to evaluate whether the actual performance of the fan meets the design requirements and relevant standards.

3. Material analysis: Carry out material analysis on the key components of the fan to determine whether the material composition, performance and processing technology meet the standards.

4. Fault analysis: If the fan fails, fault analysis needs to be performed to find out the cause and location of the fault.

A coal mine of the applicant signed a "Main Ventilator System Procurement Contract" with a manufacturer of the respondent, and it was agreed that the reverse wind switching time should be ≤5 minutes. The switchover during the accident drill took 25 minutes, and the manufacturer argued that it was caused by unstable power grid voltage.

Identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of the "mine fan", the contract technical agreement, the on-site investigation case materials and other data, and made a comprehensive technical analysis. The following quality analysis opinions were issued:

The output frequency of the mine fan inverter involved in the case fluctuated ±5Hz (agreed ±0.5Hz), the damper actuator was stuck (response delay >45 seconds); the fatigue crack expansion rate at the blade root exceeded the agreed value by 3 times, and the air volume was attenuated by 30%.

The appraisal conclusion determined that defects in the control system and materials were the main causes of the reverse wind failure.

Mine fan quality appraisal report should include:

1, appraisal purpose (such as safety accident attribution, performance verification) and reference standards;

2, involved equipment model, explosion-proof certificate, operation log;

3, detection method and equipment list (such as wind turbine tachometer, direct-reading spectrometer);

4, analysis of detection data and failure correlation (such as the impact of frequency fluctuations on switching time);