Study on the filter performance of plush filter material for air conditioning return air filter
by:GESTER Instruments
2021-03-11
A large amount of dust is generated during the production of shredded tobacco and cigarette rolling in the cigarette workshop, which not only affects the production process of cigarettes, but is also detrimental to the health of laborers [1-5]. The air-conditioning system of the cigarette workshop should ensure the temperature and humidity of the workshop required by the production process, and at the same time ensure the cleanliness of the air specified by the process and labor hygiene standards. Especially in the roll-up package workshop, the process produces a large amount of dust and the air contains a high concentration of dust. Although a variety of new filter cartridge dust removal technologies have been adopted [6], the air conditioner will still be affected when the return air purification effect of the air conditioner is not ideal. The heat exchange effect of the surface cooler [7] makes the air conditioner unable to operate normally [8]. At present, the commonly used filter materials in the filter section of the air conditioning system include stainless steel plate mesh, stainless steel wire mesh, multi-layer nylon mesh or non-woven fabrics, etc. [9]. After the air conditioning of some cigarette workshops is upgraded, the sub-high efficiency filter cartridge section adopts a gradient ultra-submicron Fiber filter media [10] and plush filter media. In recent years, the research of gradient ultra-submicron fiber filter materials in the field of dust removal in cigarette workshops has been reported [11-12], but there is still a lack of research on the dust filtering performance of plush filter materials. Therefore, the filtration performance parameters of the plush filter media under different wind speeds and different dust concentrations (mainly including efficiency, resistance, and dust holding capacity) were tested and analyzed, and the comparison method was used to analyze the filtration performance of different types of plush filter media. The best filter performance section of the plush filter material is designed to provide theoretical help for selecting the best filter material for air conditioning return air filtration in cigarette workshops. 1 Materials and methods 1.1 Materials, equipment and instruments 1.1.1 Experimental dust The dust from the air-conditioning return air of the cigarette workshop (poor sliding and strong adhesion) is selected as the experimental dust. 1.1.2 The sample of the plush filter material The experimental object is the plush knitted filter material, which is a pile fabric based on knitted single-sided pad weft knitting. It is constructed and passed through a brushing process to form a uniform fluff layer on the surface. The samples in this experiment are long-pile knitted filter materials JM2 and JM5 and short-pile knitted filter materials DM (Figure 1). Among them, the flocking density on JM5 is greater than that on JM2, and the flocking length of JM5 and JM2 is longer than that on DM. The parameters of the plush filter material sample used in the experiment are shown in Table 1. 1.1.3 The experimental bench is shown in Figure 2. It consists of the experimental dust supply part, the air duct, the fixed device of the experimental filter, the pressure loss measuring device, the dust measuring device and the wind speed measurement. Equipment and other components. Among them, the dust generator sets the dust concentration range (0.6~3 mg/m3) of the inlet dust in accordance with the dust limit of the workplace air of the tobacco dust hygienic standard (2 mg/m3) [13]. The air duct is made of plexiglass pipe in order to observe the flow state of dust in the air duct. Install baffles at the inlet of the pipe, the inlet pipe section of the pipe and the fan interface, and the exhaust pipe section respectively to make the air flow in the pipe uniform, so that the experimental air flow and dust concentration can be uniform to ensure that the dust concentration can be measured in a stable state. The test ports for measuring pressure loss are respectively set on the upper air side and the lower air side, and the distance from the fixed part of the experimental filter is one-half of the diameter of the air pipe, in the form of a static pressure ring pressure measuring device. 1.1.4 Instrument FA1104 digital electronic balance (sensitivity: 0.1 mg, Shanghai Hengping Scientific Instrument Co., Ltd.); U-tube pressure gauge (Changzhou Jiangtai Electronics Co., Ltd.); GH100E dust concentration measuring instrument (Zhengzhou Guangli Technology Co., Ltd. Company); CLIMOMASTER MODEL A531 multifunction instrument (American Kanomax company). 1.2 Methods Through comparative experiments, the filtration efficiency and filtration resistance values u200bu200bof each plush filter material sample at wind speeds of 0.2, 0.4, 0.6, 0.8 and 1.0 m/s, and the dust concentration of 0.6, 1.0, 2.0 and 3.0 mg/ Filter efficiency and filter resistance value under m3. The specific measurement and calculation methods are as follows: (1) Filtration efficiency. Determine the inlet dust concentration by controlling the dust generation time and the amount of dust, and use the dust concentration meter to collect the dust concentration after the filter material, then the filtration efficiency is: ηu003d(C1-C2)/C1 where: C1—dust concentration at the dust inlet, mg/m3; C2—dust concentration at the outlet, mg/m3. If dust is emitted into the pipeline steadily and continuously, the inlet dust concentration C1 is: C1 u003d G/tQt (2) where: G-dust generation, mg; Qt-gas flow, m2/s; t-dust generation time, s. In the same way, the outlet dust concentration C2 can be converted from the dust collection amount G2 in the filtered gas: C2u003dG2/tQt(3)(2) gas flow rate and filtering wind speed. The CLIMOMASTER multi-function instrument is used to measure the airflow velocity in the pipeline, calculate the gas flow, and use the dynamic pressure method (piping pipe tube) for proofreading. The calculation formula is: vu003d 2Pdρ (4) Qtu003dAV (5) where: Qt — Gas flow rate, m2/s; v— average air velocity (filter wind speed), m/s; A—measured cross-sectional area, m2; Pd—average dynamic pressure, Pa; ρ—gas density, kg/m3. (3) Filter resistance. Use a pressure gauge to measure the pressure difference before and after the filter material in the actual filtration process to obtain the filtration resistance.
When you find yourself in need of textile testing equipment tensile tester manufacturers, you may not know where to begin. And that's OK! Search out GESTER International Co.,Limited to handle your textile testing equipment needs.
As President of GESTER International Co.,Limited, I am committed to the enduring values of integrity, accountability, innovation and flexibility, value creation and social responsibility.
This is crucial when you need to maintain innovative information in textile testing equipment.
When you find yourself in need of textile testing equipment tensile tester manufacturers, you may not know where to begin. And that's OK! Search out GESTER International Co.,Limited to handle your textile testing equipment needs.
As President of GESTER International Co.,Limited, I am committed to the enduring values of integrity, accountability, innovation and flexibility, value creation and social responsibility.
This is crucial when you need to maintain innovative information in textile testing equipment.
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