De Qiang Chang

Effect of Surface Finishing on Filtration Performance of a Regenerable Filter Media

The periodical filter cleaning process has a marked effect on the filtration performances of fabric filters. A model was proposed to express the non-uniformity of residual dust cake distribution after filter cleaning in a simpler manner, in which two parameters, i.e. the surface cleaning fraction, f , and the residual dust load on un-cleaned surface, RD , were introduced. Three filter media with different surface finishing were tested and f and RD were calculated by using the testing results. It can then be concluded that filter with surface finishing of calendar + singe has a better filter regeneration effect than that of singe + calendar. Lamination with PTFE membrane results in an excellent filter regeneration effect.

Research on Thermal Degradation Kinetics of Polyphenylene Sulfide Filter Media

In order to study the thermal stability of PPS (polyphenylene sulfide) filter media, by means of thermogravimetry(TG), thermal degradation kinetics behavior of two kinds of PPS filter media were analyzed. The kinetic parameters of PPS filter media were obtained according to Flynn-Wall-Ozawa method. Thermal stability of PPS filter media was discussed. It was found that the initial decomposition temperature and activation energy of N3 sample are all higher than B1 sample, the thermal stability of N3 sample is better than B1 sample, and kinetic analysis can be used as an important method to evaluate the thermal stability of filter media.

Study of Typical Filter Material on Dust Cleaning

filter get peoples attention increasingly as it has become the core of dust bag. In this paper, cleaning process residual resistance and peel rate of dust cleaning cycle were studied. Experimental results show that the initial resistance of the filter were close to the filters, polyester dust filter has a high cleaning strip ratio and a larger interval.

Evaluation on Filter Cleaning Performances Measured by VDI and JIS Testing Rigs for Cleanable Fabric Filter

VDI type-1 rig and JIS rig are the two major testing rigs for cleanable fabric filters. We measured the filter cleaning performance using these rigs and the results were compared in order to characterize the two testing methods. It is found that filter cleaning has no direct relation with flow type of test rig. And configuration differences between VDI type-1 and JIS rigs causes the various differential pressure development curves in which VDI type-1 rig shows a little higher cake release effect than JIS rig. Moreover, a new concept of impulse per unit area is introduced for the evaluation on filter cleaning performance in a quantitative way.

Research on Air Purification Performance of Typical Filter Media

Filter media is designed for industrial dust removal, but in some industrial sites, it is mainly used for air purification. So in the paper, we study air purification performance of typical filter media, including filtration efficiency, resistance, and stage efficiency. The experimental results show that wind velocity has a little effect on filtration efficiency for particulate matter in air. Besides, this paper compares the air purification performance of different filter media.

Experimental Study on the Durability Performance of PPS Filter Media

The durability performance of PPS filter media is experimentally studied in the paper. It is found that, under 200°C and atmospheric condition, both machine direction strength and transverse direction strength of PPS increase at the beginning and then gradually decrease with the increase of duration time. The transverse direction change for both strength and elongation is higher than the machine direction. The melting point of PPS decreases with the increase of duration time. And the melting point can be taken as one of durability index for the PPS filter media.

Effect of Sample Size of Needle Felt on its Strength Measurement

Strength and elongation are two important parameters for evaluating the durability property of needle felt which is now widely used for the air pollution control. It is necessary to measure them as reasonable as possible. The paper researches on the effect of sample size on the strength measurement of needle felt. The results show that sample width of 5cm and sample length of 20cm are suitable value for strength measurement of needle felt and sample length has a bigger effect on strength measurement of needle felt than sample width.

Effect of Filter Media Structure on Fine Particle Filtration

Particles come in a wide range of sizes. Fabric filter with different structure shows different filtration performances on fine particle. In the paper, two types of filter media structure, i.e. non-woven structure and membrane structure are compared and studied. It can be seen that the pressure drop of membrane filter is apparently much higher than that of non-woven structure for it owns a density membrane. Membrane structure gives apparently higher efficiency for fine particle than non-woven structure.

Research on Fine Particles Capture of Baghouse Filter Media

Industrial dust emission is one of the main sources of fine particle especially for PM2.5 in atmosphere. Filter media is the key component for baghouse. In the paper, several normal needle felt filters and membrane filter are studied through experiments. The performances of filter such as resistance, capture efficiency for total particle and number counting efficiency for fine particle are tested.The experimental results show that the resistance of filter increase after aging, the resisitance increasing rate of membrane filter is the smallest; The efficiencies for total particles of normal filter are above 99.9% at clean state, and 99.99% at stable state after aging; Although the filters have high efficiency for total particle, but the number counting efficiency for 10μm particle is 94%-99%, and 52%-92% for 2μm particles. New filters for fine particles are needed.

Experiment Investigation on Two Filter Medias for Air Filtration

As the fast development of industry, clean air quality environment are needed in more manufactory fields. Filter media is the key material for high efficiency filtration. In this paper, glass fiber filter and PTFE membrane filter are studied with filtration test. The results show that glass fiber filter has low porosity, lead to lower penetration and higher resistance than PTFE filter. Penetration of filters decrease with mass load increasing and face velocity decreasing. Resistance increase with mass loading and face velocity increasing.