Quality appraisal of rotary drum dryer

rotary drum dryer takes the synergy between heat conduction and material tumbling motion as its core principle. By optimizing the cylinder inclination angle, rotation speed and hot air system, it achieves the synergy of material moisture content uniformity, thermal efficiency and processing capacity. It is widely used in fields such as slag drying, chemical raw material dehydration, biomass fuel drying and sludge treatment. In cement production, it is used for pre-drying of mineral powder; in the chemical industry, it meets the continuous drying needs of high-humidity materials; in the field of environmental protection, it realizes sludge reduction and resource utilization. Compared with traditional drying equipment, the rotary drum dryer has the characteristics of wide heat source adaptability, strong overload resistance and low maintenance cost. It is the core equipment of the industrial continuous drying process.

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

As the energy efficiency requirements of drying processes increase, related quality dispute cases have increased significantly. The judicial dispute focuses on:

1, performance index dispute: whether the thermal efficiency meets the standard, and the moisture content of the discharge material fluctuates beyond the standard;

2, material defects: insufficient Cr content in the heat-resistant steel of the cylinder, and the thickness of the wear-resistant layer of the lifting plate Uneven;

3, process problems: installation deviation of the roller bearing seat, air leakage rate of the sealing device;

4, contract performance dispute: key configurations (such as frequency conversion speed control system, exhaust gas treatment module) are not consistent with the technical agreement.

Rotary Dryer Litigation Quality Appraisal mainly includes the following technical methods:

1. Appearance inspection: Check the overall appearance, structural dimensions, material specifications, welding quality, etc. of the rotary dryer.

2. Performance test: Test the drying capacity, thermal efficiency, energy consumption and other performance indicators of the drum dryer.

3. Material analysis: analyze the composition, hardness, wear resistance, etc. of the materials used in the drum dryer.

4. Process evaluation: Evaluate whether the manufacturing process of the rotary drum dryer meets the design requirements and whether there are defects or errors.

A cement factory of the applicant signed a "Φ3×20m slag dryer purchase contract" with an equipment manufacturer of the respondent, agreeing that the thermal efficiency is ≥ 60%. After being put into operation, gas consumption exceeded the standard by 30%. The manufacturer argued that it was caused by fluctuations in the moisture content of the raw materials.

identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of the "Rotary Drum Dryer", the contract technical agreement, the on-site inspection case materials and other data, and made a comprehensive technical analysis. The following quality analysis opinions:

The actual inclination angle of the barrel of the drum dryer involved in the case is 7° (agreed 3°), resulting in insufficient material retention time; the heat exchange area of the hot blast furnace has shrunk by 15%, and the thermal efficiency is only 52%; the wear-resistant layer of the lifting plate is partially missing, and the material throwing uniformity deviation is >40%.

The appraisal conclusion concluded that equipment design and manufacturing defects were the main cause of insufficient energy efficiency.

Rotary drum dryer quality appraisal report should include:

1, appraisal purpose and reference standards;

2, involved specifications, production batch number, construction record;

3, detection method and equipment list;

4, test data and failure correlation analysis;