温度和时间因素对滤料水解特性的影响

Influence of temperature and time on the hydrolysis characteristics of filter media

滤料是决定袋式除尘器除尘效率和污染物排放质量浓度的关键因素,在工业使用过程中经常出现水解破损的问题。为研究温度和时间对滤料水解特性的影响并对比不同滤料的耐水解性能,采用蒸汽试验法在高温高压环境下模拟并加速滤料的水解反应。结果表明:在135℃、80%湿度、0.22 MPa相对压力的环境中水解12 h后涤纶滤料纬向断裂强力保持率为61.6%,纬向断裂伸长率保持率为90.6%;亚克力滤料经向断裂强力保持率为93.6%。中性环境下,延长水解时间或提高水蒸气温度可加速滤料水解,水解后滤料表面出现褶皱,内部纤维卷曲,断裂强力降低,断裂伸长率先增后减,并伴随出现收缩现象;红外光谱中无新官能团产生,亚克力滤料耐水解性能优于涤纶滤料。

Filter material is a key factor that determines the dust removal efficiency of bag filters and the emission concentration of industrial pollutants. But the problem of hydrolysis and damage occurs frequently in complex industrial using environments. To explores the influence of temperature and time on the hydrolysis characteristics of filter material and compare the hydrolysis resistance of polyester filter material and acrylic filter material, the steam experiment method was used to simulate and accelerate the hydrolysis reaction of the filter material under high temperature and high-pressure environment. The two kinds of filter materials were placed in a high-pressure steam sterilizer and different times and temperatures for the hydrolysis experiments were set. Then we measure shrinkage, breaking strength, breaking elongation, infrared spectrogram, and observe the macroscopic and microscopic changes before and after the experiment. The experimental results show that after 12 hours of hydrolysis in an environment of 135 ℃ temperature, 80% humidity, and 0.22 MPa relative pressure, the weft broken strength of polyester filter material is reduced from 2 744 N to 1 690 N, the retention rate is 61.6%, the warp broken strength of acrylic filter material is reduced from 876 N to 820 N and the retention rate is 93.6%, and the weft elongation at break of polyester filter material is decreased to 90.6% of the initial value. In a neutral environment, prolonging the reaction increasing the temperature can accelerate the hydrolysis of the filter material. After hydrolysis, the length of the filter material was significantly shortened, and the surface was wrinkled. Under the microscope, the fiber curl inside the filter material was observed, and the pores between fibers were increased. There were no new functional groups in the infrared spectrum, but it had obvious O—H bond characteristics that can prove the hydrolysis reaction. It can be seen from the comprehensive performance changes of filter material that the hydrolysis resistance of acrylic filter material is better than that of polyester filter material.