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Abstract

High-temperature filtration is one of the most promising developments in particle collection technology. Process gases if cleaned (filtered) at elevated temperatures, then processes can be made more efficient in terms of energy and more integrated in terms of process technology. The present study embodies the effect of high temperature and dust concentration on the performance of different filter media (P84 with PTFE scrim and P84 with P84 scrim) in terms of emissions, filtration efficiency, pressure drop and other related factors. At low temperature and higher feed dust concentration level of 90 g/m³, P84/PTFE shows lower emissions in comparison to P84/P84, but at higher temperature the emissions were similar with different dust concentration levels for both the fabrics. However, at lower feed dust concentration (5 g/m³), the emissions from both fabrics are similar in the experimental region of gas temperature. Filtration efficiency was found to increase at elevated temperatures but at the cost of increased residual pressure drop. In order to predict the performance of filter fabric at high temperature by testing at lower temperature, empirical equations were developed taking into account the operating temperature and dust concentration.

Keywords

Dust concentration filter fabric filtration efficiency high-temperature filtration emission pressure drop

Introduction

The separation of solids from fluids by textile filter media is an essential part of countless industrial processes, contributing to purity of product, energy conservation, improvements in process efficiency, recovery of precious materials and improvements in pollution control. In fulfilling these tasks, the media may be expected to operate for quite lengthy periods, frequently in the most arduous of physical and chemical conditions. As performance is crucial to the success of an operation, fabric failure during use could result in heavy penalties, for example, owing to loss of product, maintenance and lost production costs and possibly environmental pollution costs [1].

Among various arduous situations, filtration at high temperature is one of the most challenging tasks. This has led to many promising developments in particle collection technology [2]. If the gas streams can be cleaned at elevated temperatures, then processes can be made more efficient in terms of energy and more integrated in terms of process technology [3]. Practical experience of using high-temperature filtration shows that apart from utilizing the heat of production gases, the potential advantages of it may be also expressed in the possibilities of an increase in equipment service life due to its high dew point operation and saving in capital and operating expenditure [4 –6]. However, high filtration temperatures, while beneficial for cycle efficiencies, impose severe limitations on the mechanical durability and corrosion resistance of components in the cleaning gas unit among other aspects. Appropriate hot cleaning gas technologies are therefore being developed, and there are numerous R&D programs ongoing worldwide. High-temperature filtration technology is expensive due to high costs of construction materials and filter elements. Another disadvantage is that the elevated temperature means increased viscosity of gas (streamline flow range) and consequently much higher resistances. Increased temperature also means decreased gas density with a consequent reduction in blower performance [7].

Fabric or rigid filters are frequently used for the separation of the fine dust particles from gas streams. In bag filters, the filter medium is flexible which makes them less susceptible to thermal shock, but gives more propensity to a loss of material strength through rough handling, excessive temperature and corrosion. The characteristics of flexible media are more likely to change at high temperature than rigid media. The key property of high-temperature resistant fibers is their continuous operating temperature. Fibers can survive exposure to temperatures above their continuous operating temperatures, but the high heat results in loss of tensile strength of fabric and less effective cleaning due to shrinkage [4,8 –11]. On the other hand, rigid filters usually have higher resistance to temperature and corrosion, and collection efficiencies which are typically greater than 99.9% under both oxidizing and reducing gas environments. Although many studies have been carried out in this field of high-temperature filtration, most of the studies were oriented towards ceramic rigid filter or metal filters. It may be noted that ceramic candles have in general much higher resistance to temperature than bag filters. This aspect would significantly impact the techno-economic assessment as it would be possible to operate the dedusting system at higher temperatures and therefore reducing the necessity of cooling down the syngas, which penalties the global efficiency of the installation. However, in earlier studies [12,13], PTFE bag filters have been found to be an advantageous alternative to ceramic candles under high temperature and high pressure conditions considered within the study (200–370℃ and up to 7.5 barg, respectively). Filter media has exhibited significant technical improvements in the operation and important reductions in the investment and operational costs. The material is also easier to handle and less fragile than rigid element.

The performance of a filter fabric in terms of filtration efficiency and pressure drop is likely to get affected at higher temperatures. Gas viscosity tends to increase at high temperature which can influence cake characteristics and differential pressure across the media. Higher temperature can also lead to more volume flow through the media. All these changes can also affect the quantity and nature of emitted particles. In one of the studies [2], it was seen that the number concentration reduced with the increase in temperature for the two filter media, i.e. metal fiber fleece and woven wire mesh. Temperature can also play a vital role on the cleaning efficiency and pressure drop across the fabric filter. In another study [14], the effect of temperature was seen on the pressure drop across the cake of coal gasification ash formed on a ceramic filter. According to the study, there was an increase in residual pressure drop while the cleaning efficiency of the ceramic filter decreased as temperature increased. The temperature effect was found to be deeply related with the fluid viscosity, which also increases with temperature. However, there is a dearth of literature with regard to the impact of high temperature on the performance of flexible filter media. The behavior of filter fabric at its maximum operating temperature is important since high-temperature filtration and temperature surges are common in the industrial conditions. Further, effect of temperature for filter fabric exposed to different level of dust concentration is also important as operating parameters could vary widely depending on filtration situation. However, no previous research was found published on the subject.

From the testing point of view, the testing of filter media at high temperature is very difficult and costly. High-temperature filter testing requires high temperature resistant equipment and accessories which has resulted in very high cost of the filtration equipment. Also, considerable amount of energy and time are used in heating up of the instrument. So, in this study, an attempt is also being made to develop mathematical models so that the performance of filter media at high temperature can be assessed by testing at low temperature.

Experimental

Materials

Two different filter fabrics viz., P84 with PTFE scrim and P84 with P84 scrim have been used for the filtration testing. Both fabrics are commonly used at high temperatures. The fibers are similar in their characteristics. However, the maximum temperature at which filter materials can be operated continuously is different for different fabrics. The technical specifications of the filter fabrics tested at standard atmosphere of laboratory (temperature 20℃ ± 20℃ and relative humidity 65% ± 2%) are shown in Table 1. Each of the samples was tested for emissions, filtration efficiency, emitted particle characteristics in terms of number concentration and mass concentration and pressure drop.

Table 1.

Properties of filter fabrics used.

Fabric	Physical properties
Fabric	Area weight (g/m²)	Thickness (mm)	Air permeability (m³/m²/h)	Mean pore size (µm)	Max. continuous temperature (℃)
P84/PTFE	530	2.4	570	27.8	220
P84/P84	500	2.2	600	29.3	200

Conduct of experiment

The test is performed at MMTC 2000 filtration test rig (PALAS GmbH) with heating arrangement up to 250℃ and possessing online aerosol spectrometer (Promo® 2000 H Light-scattering spectrometer, PALAS GmbH). The particle mass and number concentration (C_m and C_n, respectively) are measured by the aforesaid particle measurement system. Filter test allows carrying out filter tests according to VDI 3926 [15], including the aging of the media. The schematic diagram of filtration apparatus is shown in Figure 1. It consists of aerosol feeding zone, draft zone, filter unit zone and pulsing zone. During filtration, aerosol passes through the filter fabric which retains dust particles depending on its efficiency. The study of outgoing particles is essential for judging the filtration performance of fabric. Estimation of outgoing particle characteristics and its amount can be estimated by online spectrometer and mass deposited over high efficiency particulate air (HEPA) filter over a predetermined time frame. However, with the particle deposition, a negative effect is associated with increased pressure drop which indicates restriction of air flow through the media. The filter material is therefore periodically regenerated by pulse-jet cleaning. This operation involves injecting high-pressure back-pulse air into the filter for a very short time. Back pulse-air injection causes removal of deposited particles from the filter surface for its regeneration. During pulse cleaning, the particles retained by the fabric are to be removed either at the upper limit of pressure drop or at a pre-set filtration time to sustain a semi-continuous filter operation. However, in the present case, the filter media is cleaned with a back pressure pulse as and when a defined peak pressure level is reached. This apparatus operates under the principle of negative pressure and the increasing pressure drop during filtration is measured at the test filter. The circular cut test specimen has a diameter of 169 mm and the exposed circular diameter during testing is 150 mm.

Figure 1.

Schematic diagram of filtration apparatus according to VDI/DIN standard 3926.

The filter media were tested using fly ash dust with face velocity of 2 m/min, dust concentration (5 and 90 g/m³), pulse-jet tank pressure 5 bar and valve opening time 60 ms. The particle size characteristics are X₁₀ = 0.41 µm, X₅₀ = 7.2 µm and X₉₀ = 42.3 µm. Each experiment was carried out in three phases, viz., initial phase (conditioning), aging phase and final test phase. Initial phase was carried for five cycles and the filter media was cleaned every time with the cleaning pulse when differential pressure of filter media reaches at 500 Pa. After initial phase of conditioning, aging of filter media was carried out for 45 min with the cleaning cycle at 5 s. Final test was carried for 1 h with the cleaning done when differential pressure of filter media reached at 500 Pa. It is important to note that due to decrease in gas density at higher temperature, flow volume/filtration velocity tends to increase. In the present set-up, filtration was carried out at a constant volume/constant flow velocity throughout the testing phase by controlling suction motor.

In the present study, gravimetric emissions were evaluated considering total test time for experimentation which includes initial phase, aging phase and final test phase. It may be noted that each test does not have same number of pulses. However, the number of pulses at “initial phase” and “ageing phase” is same for the materials tested. During the final phase, test was carried out at fixed 1 h irrespective of number of pulses/test. The value of mass concentration and number concentration is taken at final test phase. Generally, in the filtration process, the emissions data are to be considered from the final test phase after the aging and conditioning of the filter media because filtration process is transient in nature and is not solely dependent on the filter fabric but also on the particles entrapped within and primary cake layer on the surface of filter fabric [16]. Since the buildup of primary cake takes place in the initial phases of the filtration, most of the particles are emitted during these initial phases. Gravimetric emissions, and both mass concentration and number concentration are of practical relevance because of the difference in the collection of data as well as mode of experimentation. Both mass and number concentration are important to study, as the mass of the particles varies with the size of the particles. If in case the number concentration is same but the mass concentration varies, it can be clearly assessed whether the particles emitted are finer or coarser. Total time taken for the experiment with 5 g/m³ dust concentration is approximately 5 h (including condition and aging), whereas filtration time is approximately 2 h for 90 g/m³ dust concentration. The difference in filtration time is due to quicker dust cake formation and higher level of clogging in the latter case. It is important to note that the aforesaid parameters provide cumulative performance of the filter media over the respective test period.

Experimental design

In the present work, three experimental factors at different levels are used to investigate the influence of fabric type (two levels), dust concentration (two levels) and temperature (four levels) on filtration performance. Maximum temperatures for the two different fabrics are selected based on their suitability for use. Since our main focus was to study the effect of temperature, four levels of temperature were chosen. The lowest temperature at 30℃ is chosen in order to predict the performance of filter fabric at high temperature by testing at lower temperature. Dust concentrations are selected at two levels to see their effect at different temperatures. The experimental layout is shown in Table 2.

Table 2.

Layout of experimental plan according to standard order.

Filter media	Run order	Temperature (℃)	Dust concentration^a (g/m³)
P84 + P84 Scrim	1	30	5
	2	160	5
	3	180	5
	4	200	5
	5	30	90
	6	160	90
	7	180	90
	8	200	90
P84 + PTFE Scrim	9	30	5
	10	180	5
	11	200	5
	12	220	5
	13	30	90
	14	180	90
	15	200	90
	16	220	90

At standard atmosphere of laboratory (temperature 20℃ ± 2℃ and relative humidity 65% ± 2%).

The whole experimental run was replicated twice. Replication is repetition of an experiment or observation in the same or similar conditions. It is used in an experimental design and analysis to minimize bias and error variance due to nuisance factors. Replication is important because it adds information about the reliability of the conclusions or estimates to be drawn from the data. The effect of replication has been studied as effect of block. A block represents a group of experimental runs conducted under relatively homogeneous conditions. The experimental run was also randomized. The experiments are performed in a random order as the serial number in the order of 3, 6, 7, 2, 1, 8, 5, 4, 13, 15, 14, 11, 9, 16, 12 and 10. Reason for randomization is for effective statistical analysis through unbiased estimation of the impact of factors and for validity of inference drawn.

The analysis of variance (ANOVA) technique was conducted to see the effect of individual factors on the filtration performance. From the ANOVA results, % contribution of different factors was evaluated based on the following expression

% {contribution = (SS}_{f} - {df}_{f} V_{e} {) / SS}_{T}

where SS_f is the sum of square of the factor, df_f is the degree of freedom of the factor, V_e is the mean square of pooled error and SS_T is the total sum of squares.

Results and discussions

Emission and filtration efficiency

From the ANOVA for emissions study (Table 3), it can be seen that dust concentration has a major impact on the emissions than the temperature. It has been observed that the impact of fabric type is very small compared to the other main effects such as dust concentration and temperature. The properties of the fabric are very similar in the present study (Table 1), leading to similar impact under various conditions. It has also been observed that the effect of dust concentration is much higher than the effect of temperature. Interaction among the main effects can also be seen in Table 3. It is important to note that ANOVA results show a generalized view about the impact of fabric type over the test time. However, upon detailed observations at different levels of temperature (Figure 2), it can be seen that at low temperature both the fabrics behave differently with higher level of dust concentration (90 g/m³), whereas at lower level of dust concentration their impact is almost similar. At high levels of temperature, both the fabrics behave in a similar manner at different levels of dust concentration. However, at lower feed dust concentration (5 g/m³), the emissions from both fabrics are similar in the experimental region of gas temperature.

Figure 2.

Plots for temperature versus emissions.

Table 3.

ANOVA (% contribution) of different factors.

	% Contribution
Parameters	Fabric	Dust concentration	Temperature	Fabric × dust concentration	Fabric × temperature	Dust concentration × temperature	Fabric × temperature × dust concentration
Emissions per test (g)	1.16	69.6	20.42	–	1.93	2.66	1.15
Mass concentration (mg/m³)	–	77.5	10.31	–	2.0	7.9	–
Number concentration (P/cm³)	–	92.82	2.34	1.4	–	–	–
Pressure drop (Pa)	2.86	88.06	5.55	–	–	1.32	–

The decrease in emissions at higher temperature can be attributed to the fact that at higher temperatures the gas viscosity increases due to which the drag force on gas flow increases and particles get sintered at high temperature. This results in high compaction of dust cake due to which there is a reduction in pore size of dust cake. Also, at high temperature, the density of air decreases which makes pulse pressure less effective. Therefore, during pulsing at high temperature the dust cake formed on the fabric is not dislodged completely, and higher amount of dust is retained on the fabric resulting lower emission due to greater cake filtration.

It is also noted that at higher dust concentration, emissions become higher to a large extent for both the fabrics, i.e. P84/P84 (P84 with P84 scrim) and P84/PTFE fabric (P84 with PTFE scrim) (Figure 2). At higher dust concentrations, greater number of finer particles is present in the upstream side. During pulsing, greater numbers of smaller particles in the upstream are likely to penetrate through the media by direct penetration mechanism [16] and also the possibility of seepage (for previously trapped particles) increases leading to higher emission.

Figure 2 shows that at lower temperatures and particularly at higher dust concentration, P84/PTFE fabric gives much lower emissions than P84/P84 filter fabric but at higher temperatures the emissions are almost similar for all dust concentrations. It may be noted that at higher dust concentration the quantity of fine particles will be higher. It has been noted that P84/PTFE filter fabric has higher fabric weight (GSM) and is thicker than P84/P84 filter, besides the pore size of the P84/PTFE filter fabric which is lower than P84/P84 filter fabric (Table 1). Therefore, the possibility of entrapment of fine dust particles is higher in the former case. However, at lower dust concentration, difference in emission for both the fabric becomes marginal as the quantity of small particles reduces substantially. At higher temperatures, the filtration is predominantly done by the dust cake formed on the surface (surface filtration) of the filter fabric. For both fabrics, as mentioned earlier, an extremely compact dust cake is formed at higher temperature. Therefore, since filtration is done primarily by the dust cake (primary cake) and not by the fabric, similar emissions have been observed for both the fabrics at higher temperatures.

Figure 3 shows the increasing trend of filtration efficiency with the increase in temperature. This increase in efficiency with the temperature can be explained based on emission study (as filtration efficiency is inversely related to the emissions). However, it is important to note that at higher dust concentration, the filtration efficiency is higher in spite of greater emissions with the increase in dust concentration. This can be explained as the amount of dust blocked by the fabric is much higher than the emission; therefore, even if the emissions at higher dust concentration are higher, it will give higher gravimetric filtration efficiency when compared with lower dust concentration.

Figure 3.

Plots for temperature versus filtration efficiency.

Mass concentration (C_m) and number concentration (C_n)

In case of cake filtration, once the primary dust cake is formed over the fabric, the role of fabric is secondary in the outgoing emission of dust particles. This leads to the difference in the trend of gravimetric emissions and emissions by mass concentration. From ANOVA results (Table 3), it can be seen that dust concentration has the major impact on both the mass concentration and number concentration. As mentioned earlier, both the parameters were evaluated at the final test phase. This indicates that the corresponding test data depict filter behavior towards a stable state. It can be observed from Figure 4 that at higher dust concentration, there is a significant rise in the mass and number concentration for both the filter fabrics. Also, with the increase in temperature for higher dust concentration, mass concentration is reduced largely whereas reduction is relatively less in the case of number concentration. This is due to the fact that during filtration with higher dust concentration, formation of dust cake is rapid which invariably get compacted as the level of temperature is increased. This will result in a specific surface characteristic of filter media wherein only the finer dust particles are able to pass through. Since the mass of finer particles is less, although the number concentration is slightly reduced with the increase in temperature, the change in the mass concentration is very prominent. It is also observed that the effect of temperature particularly on the mass concentration is different at different level of dust concentration. It signifies the influence of interaction “dust concentration × temperature” as also evident from ANOVA table. At lower dust concentration both mass and number concentration are not much affected. This is due to the fact that at lower dust concentration, the number of smaller particles in the upstream is quite less.

Figure 4.

(a) Plots for mass concentration versus temperature. (b) Plots for number concentration versus temperature.

Also, it has been observed from Figure 4 that at higher level of dust concentration and at low temperature, mass and number concentrations for P84/PTFE medium are less than the P84/P84 filter fabric but at high temperature almost similar emissions are observed. The above findings can be explained based on the structural differences of two filter media. However, at higher temperature, the role of dust cake settled on the fabric surface plays a major role and as a result both the fabrics show similar emissions in terms of mass and number concentration at higher temperature.

Residual pressure drop

From the study of ANOVA results (Table 3), it can be seen that dust concentration has the major impact on residual pressure. It is important to note that pulsing is actuated on the basis of onset of limiting pressure peak (500 Pa). Residual pressure drop is the pressure drop across the filter fabric just after cleaning. A low and stable value of residual pressure drop is desirable during filtration. The rate of increase of residual pressure drop during the filtration cycle is very important because it determines the lifetime of the filter bag. Figure 5 shows the impact of dust concentration and temperature on residual pressure drop. The increase in residual pressure drop at higher dust concentrations can be attributed to higher presence of numbers of smaller particles leading to depth filtration. As mentioned earlier, during pulsing, greater numbers of smaller particles in the upstream are likely to penetrate through the media by direct penetration mechanism and seepage. It may be added that a fraction of finer particles still remain in the structure. Finer particles also behave as suspended dust particles (even after cleaning) which are captured by incoming dust-laden air and re-entrainment increases. The finer particles enter the pore structure of the filter fabric and are retained inside the structure decreasing the pore size and porosity of the filter media. Also, at higher dust concentrations, the frequency of pulsing increases. It is important to note that there is a decrease in cleaning efficiency with the increase in the number of cycles [17]; a surface deposit is more easily removed than a dust that has entered deep within the fabric. Since pulsing is more frequent, it leads to higher penetration of the particles as pores open and close more frequently. Hence, residual pressure drop tends to increase during filtration at higher dust concentration.

Figure 5.

Plot for residual pressure drop versus temperature.

It has also been observed that residual pressure drop increases with the increase in temperature. The effect of temperature on the pressure drop across the dust cake is mainly related with the change in gas characteristics at high temperature. At high temperature, compactness of cake increases leading to smaller pore size in cake. In addition, higher pressure drop can also be associated with adhesion of some low-melting point compounds to the filter fabric surface and forming a bridge-like structure which blinds the surface. During experimentation, it was observed that the dislodgement was visibly less at higher temperatures. This indicates that the cohesion of the particles in the cake and its adhesion with the fabric is higher at higher temperature. This is also in agreement with earlier researchers [18,19] who have found that at higher operating temperature, there is decrease in cake porosities and increase in specific dust cake resistances. Further, at higher temperature, there is decrease in gas density which decreases the effectiveness of pulsing in pulse jet filtration [20]. All these changes result in higher level of pressure drop at higher temperature. It is also noticed that at higher dust concentration, the rate of increase in residual pressure drop is higher with the increase in temperature. This can be explained on the basis of accumulation of greater number of small particles within the structure of filter media at higher dust concentration [21], removal of which becomes more difficult at higher level of temperature.

It is also observed that at higher dust concentration coupled with low temperature, residual pressure drop across P84/PTFE is higher than P84/P84 filter fabric. As filter fabric P84/PTFE possesses higher mass per unit area and thickness, it will exhibit greater and longer pore flow channels. Therefore, the extent of depth filtration is likely to be higher under the aforesaid condition which leads to higher residual pressure drop. It may be added that apart from dust–fabric interaction, the role of fabric (in isolation with dust) is also important. Theory of Darcy’s law suggests that pressure drop is dependent on the fabric resistance and filtration velocity. However, during the experimentation, filtration velocity was kept constant; therefore, the role of fabric resistance is an important parameter in influencing residual pressure drop. Since P84/PTFE filter media have higher mass per unit area and lower air permeability than P84/P84 media, the pressure drop across P84/PTFE media is higher. But this effect of higher mass per unit area becomes secondary as the temperature is increased and mainly depends upon cake properties, and as a result residual pressure remains similar for both the fabrics at higher temperature.

Empirical models to predict the performance of filter fabric at high temperature by testing at low temperature

For the prediction of the performance of filter fabric at high temperature by testing at low temperature, the data available during testing of filter fabric were used to develop regression equations (Table 4) through backward elimination technique and using p value of 0.05. High R² values indicate that all the filtration parameters can be well predicted at different levels of dust concentration and temperature of filtration. The equations can be used to predict filtration parameters at high temperature by testing the media at lower temperature (i.e. room temperature). The above strategy is useful, as testing and characterization of filter media at high temperature is difficult and costly. Once the relationship is known, prediction of filter behavior is possible at any other temperature (within the experimental region).

Table 4.

Empirical equations for the prediction of performance of filter fabric at high temperature by testing at low temperature.

Parameters	Regression equations	R²
P84/PTFE fabric
Emissions (g) × 10⁴	122.369 + 1.018T + 0.01D²− 0.006T²	0.965
Filtration efficiency (%) × 10⁴	999790.845 + 0.019D²+ 0.002T²− 0.003DT	0.973
Residual pressure drop × 10³	594.301 + 0.093D²+ 0.036DT	0.960
Cn (P/cm³)	31.03 + 0.151T + 0.013D²− 0.001T²	0.999
Cm (mg/m³) × 10⁴	28.609 + 5.477T + 0.355D²− 0.023T²− 0.069DT	0.997
P84/P84 fabric
Emissions (g) × 10⁴	112.702 + 2.01D + 1.07T − 0.006T²− 0.005DT	0.978
Filtration efficiency (%) × 10⁴	999799.988 − 0.658T + 0.017D²+ 0.004T²− 0.002DT	0.988
Residual pressure drop × 10³	576.385 + 0.145D²+ 0.006T²+ 0.016DT	0.989
Cn (P/cm³)	17.324 + 2.041D + 0.302T − 0.002T²− 0.003DT	0.997
Cm (mg/m³) × 10⁴	− 257.515 + 21.246T + 0.52D²− 0.098T²− 0.143DT	0.963

D: dust concentration (g/m³); T: temperature (℃).

Conclusions

Based on the investigations on the effect of high temperature and dust concentration on the performance of filter fabric in terms of filtration efficiency, pressure drop and others factors, following conclusions have been drawn:

Emissions through filer media decrease with the increase in temperature and increase with the increase in dust concentration.

At higher dust concentrations and also at high temperature, pressure drop across the filter media increases.

The filtration efficiency is found to increase at elevated temperatures but at the cost of increased residual pressure drop.

At lower temperature, P84/PTFE fabric exhibits lower emissions than P84/P84 filter fabric particularly at higher dust concentration (90 g/m³), but at higher temperatures the emissions are almost similar. At lower feed dust concentration (5 g/m³), the emissions from both fabrics are similar in the experimental region of gas temperature.

Models have been developed for predicting the performance of filter fabric at high temperature using the filter media test data at lower temperature.

Footnotes

Acknowledgements

The authors acknowledge EVONIK industries, Germany for providing the filter fabrics for carrying out the research work. They especially thank Dr S.K. Basu, Director Manmade Textile Research Association (MANTRA), Surat (India), for his kind supports to carry out the experimental work.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article.

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Effect of high temperature on the performance of filter fabric

Abstract

Keywords

Introduction

Experimental

Materials

Conduct of experiment

Experimental design

Results and discussions

Emission and filtration efficiency

Mass concentration (Cm) and number concentration (Cn)

Residual pressure drop

Empirical models to predict the performance of filter fabric at high temperature by testing at low temperature

Conclusions

Footnotes

Acknowledgements

Declaration of Conflicting Interests

Funding

References

Mass concentration (C_m) and number concentration (C_n)