Method for manufacturing PTFE fiber and PTFE membrane catalyst filter using the same

Abstract

The present invention discloses a method for producing a PTFE fiber for a PTFE membrane catalytic filter, characterized in that in the process of producing a PTFE fiber for a PTFE membrane catalytic filter, a catalyst that has been homogenized in the mixing process through mixing, maturing, compressing, extruding, rolling, sintering, braiding / drawing, and slitting processes is added, the ratio of the catalyst added is 0.5% or more and 0.6% or less, and the ratio of the lubricant added is 28% or more and 30% or less.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing PTFE fibers and a PTFE membrane catalyst filter made using the PTFE fibers. More specifically, through an optimized mixing process in the stage of manufacturing the fibers, the present invention relates to a method for manufacturing PTFE fibers for manufacturing a PTFE membrane catalyst filter with improved performance, and a PTFE catalyst filter.

Background Art

[0002] As the background for the development of a catalyst filter that simultaneously reduces dust and NOx contained in exhaust gas, the emission standards for harmful gases in exhaust gas have been gradually strengthened, and there is a high interest in the development of high-performance materials and process improvements for simultaneously reducing nitrogen oxides (NOx), sulfur oxides (SOx), etc. However, the technology in Korea is insufficient, and the core technology depends on overseas advanced technologies.

[0003] In particular, due to the economic and space problems of small and medium-sized operators such as small and medium-sized incineration facilities, methods such as the combination of multiple unit facilities cause practical problems such as installation space and investment costs.

[0004] Due to such a situation, currently in Korea, large-scale facilities such as SCR and SNCR are utilized for the removal process of nitrogen oxides (NOx).

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a method for manufacturing a PTFE membrane catalyst filter for reducing fine dust and NOx contained in exhaust gas so that it can be applied to a dust collection facility operated in an existing small and medium-sized incineration facility and meet improved emission standards.

[0006] Furthermore, an object of the present invention is to provide a method for manufacturing catalyst fibers for manufacturing a PTFE membrane catalyst filter.

[0007] Moreover, an object of the present invention is to present the conditions of an optimized catalyst fiber manufacturing process.

Means for Solving the Problems

[0008] In order to solve the above problems, the present invention provides a method for mixing a PTFE powder with a De-NOx catalyst and a lubricant to produce a powder for manufacturing PTFE fibers. In the process of putting PTFE powder and De-NOx catalyst powder into a mixer that rotates by repeating dropping using gravity and centrifugal force to mix the powder, a lubricant is injected into the powder to produce a mixed powder. A method for mixing a powder for manufacturing PTFE fibers is disclosed, which is characterized in that.

[0009] According to an embodiment of the present invention, a method for mixing a powder for manufacturing PTFE fibers is disclosed, which is characterized in that the lubricant is adjusted to be injected only into the PTFE powder and the De-NOx catalyst powder and not into the wall surface of the mixer.

[0010] According to an embodiment of the present invention, a method for mixing a powder for manufacturing PTFE fibers is disclosed, which is characterized in that the De-NOx catalyst powder is 0.5% by weight or more and less than 0.7% by weight of the total weight.

[0011] According to an embodiment of the present invention, a method for mixing a powder for manufacturing PTFE fibers is disclosed, which is characterized in that the lubricant is 27% by weight or more and 29% by weight or less of the total weight.

[0012] According to an embodiment of the present invention, a method for mixing a powder for manufacturing PTFE fibers is disclosed, which is characterized in that the injection rate of the lubricant is 150 g / min or more and less than 250 g / min.

[0013] According to an embodiment of the present invention, there is disclosed a method for mixing powder for manufacturing PTFE fibers, characterized in that the rotation speed of the mixer is 10 rpm or more and 14 rpm or less, and the mixing time is 40 minutes or more and 70 minutes or less.

[0014] Further, the present invention is a method for manufacturing PTFE fibers for manufacturing a PTFE membrane catalyst filter, which is manufactured through a mixing step, an aging step, a compression step, an extrusion step, a rolling step, a sintering step, a string-making / drawing step, and a slitting step. In the mixing step, in a mixer that repeatedly drops and mixes powders using gravity and centrifugal force, when PTFE powder and De-NOx catalyst powder are put in and rotated, a lubricant is injected into the powders to generate a mixed powder. There is disclosed a method for manufacturing PTFE fibers, characterized in that.

[0015] According to an embodiment of the present invention, there is disclosed a method for manufacturing PTFE fibers, characterized in that the lubricant is adjusted to be injected only into the PTFE powder and the De-NOx catalyst powder and not onto the wall surface of the mixer.

[0016] According to an embodiment of the present invention, there is disclosed a method for manufacturing PTFE fibers, characterized in that the De-NOx catalyst powder is 0.5% by weight or more and less than 0.7% by weight of the total weight.

[0017] According to an embodiment of the present invention, there is disclosed a method for manufacturing PTFE fibers, characterized in that the lubricant is 27% by weight or more and 29% by weight or less of the total weight.

[0018] According to an embodiment of the present invention, there is disclosed a method for manufacturing PTFE fibers, characterized in that the injection speed of the lubricant is 150 g / min or more and less than 250 g / min.

[0019] According to an embodiment of the present invention, there is disclosed a method for manufacturing PTFE fibers, characterized in that the rotation speed of the mixer is 10 rpm or more and 14 rpm or less, and the mixing time is 40 minutes or more and 70 minutes or less.

[0020] The present invention also discloses a method for manufacturing a PTFE membrane catalyst filter using PTFE fibers manufactured through a mixing process, an aging process, a compression process, an extrusion process, a rolling process, a sintering process, a cord making / drawing process, and a slitting process. In the mixing process, in a mixer that repeatedly drops and mixes powders using gravity and centrifugal force, PTFE powder and De-NOx catalyst powder are put in and rotated, and a lubricant is injected into the powders to generate a mixed powder.

[0021] According to an embodiment of the present invention, there is disclosed a method for manufacturing a PTFE membrane catalyst filter, characterized in that the lubricant is adjusted to be injected only into the PTFE powder and the De-NOx catalyst powder and not onto the wall surface of the mixer.

[0022] According to an embodiment of the present invention, there is disclosed a method for manufacturing a PTFE membrane catalyst filter, characterized in that the De-NOx catalyst powder is 0.5% by weight or more and less than 0.7% by weight of the total weight.

[0023] According to an embodiment of the present invention, there is disclosed a method for manufacturing a PTFE membrane catalyst filter, characterized in that the lubricant is 27% by weight or more and 29% by weight or less of the total weight.

[0024] According to an embodiment of the present invention, there is disclosed a method for manufacturing a PTFE membrane catalyst filter, characterized in that the injection speed of the lubricant is 150 g / min or more and less than 250 g / min.

[0025] According to an embodiment of the present invention, there is disclosed a method for manufacturing a PTFE membrane catalyst filter, characterized in that the rotation speed of the mixer is 10 rpm or more and 14 rpm or less, and the mixing time is 40 minutes or more and 70 minutes or less.

[0026] The present invention also discloses a PTFE fiber manufactured by the method for manufacturing a PTFE fiber described as an example above.

[0027] The present invention also discloses a PTFE membrane catalyst filter manufactured by the method for manufacturing a PTFE membrane catalyst filter described as an example above.

Advantages of the Invention

[0028] According to the present invention, by applying a PTFE membrane to filter dust in exhaust gas on the surface of the filter and allowing NOx to react in a bag filter carrying a catalyst to remove nitrogen oxides, NOx and dust can be removed simultaneously.

[0029] Also, according to the present invention, by imparting the function of a catalyst through a mixing method from the stage of producing fibers, rather than a coating method, to a catalyst filter that depends on overseas technical capabilities and products, it becomes possible to manufacture a catalyst filter having an NOx reduction function for the final product, a bag filter.

Brief Description of the Drawings

[0030]

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Mode for Carrying Out the Invention

[0031] Hereinafter, the present invention will be described in more detail with reference to the drawings. In this specification, even for the same or similar configurations in different embodiments, the same or similar reference numerals are assigned, and the description thereof is replaced by the first description. The singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise.

[0032] In addition, when describing with reference to the attached drawings, the same reference numerals are assigned to the same components regardless of the reference signs, and redundant descriptions thereof are omitted. When it is determined that the specific description of the related known technology may unnecessarily obscure the gist of the present invention in the description of the present invention, the detailed description thereof is omitted.

[0033] Referring to FIGS. 1 to 8, the manufacturing process of general PTFE fiber is performed in the order of mixing, aging, compression, extrusion, rolling, sintering, string making, stretching, and slitting processes.

[0034] In the manufacturing process of the catalyst fiber for manufacturing the PTFE membrane catalyst filter according to the present invention, in the mixing process, the PTFE powder and the lubricant are mixed through a mixer at a certain ratio. However, in order to manufacture the catalyst fiber, the De-NOx catalyst must be put into the mixer and mixed together.

[0035] At this time, due to the De-NOx catalyst for imparting the catalyst function, the ratio of the raw materials changes in the manufacture of the catalyst fiber. As a result, differences occur in workability (continuous work), productivity (loss rate), and De-NOx effect (nitrogen oxide removal function) according to the temperature, speed, and working time in each process.

[0036] For the manufacture of the catalyst filter, since various conditions are related in this way, in order to produce the highest quality product most efficiently, research on such conditions is necessary.

[0037] In addition, according to the revised regulations as shown in Table 1 below, the emission standards for dust / nitrogen oxides have become stricter.

[0038]

Table 1

[0039] In this content, in order to meet such conditions, the optimal working conditions in the mixing process of the manufacturing process of the fiber used in the production of PTFE membrane filters will be described.

[0040] PTFE powder and De-NOx catalyst are mixed with a liquid lubricant in a mixer in powder form. However, if the ratio of the lubricant is low, problems will occur during the formation of billets in the extrusion process, and if the ratio of the lubricant is high, the cord making will not be performed well, resulting in a high loss rate.

[0041] Only when these are mixed in appropriate ratios can the occurrence of workability and productivity problems be reduced in the subsequent processes.

[0042] In addition, if the ratio of the De-NOx catalyst added for imparting the catalyst function is low, the De-NOx effect of the catalyst fiber will be low, so problems may occur in commerciality. If the ratio of the catalyst is too high, breaks will occur in the stretching and slitting processes, resulting in a decrease in workability and productivity. Since the amount of catalyst detachment caught by the needle during slitting is large, the De-NOx effect will ultimately be reduced.

[0043] Therefore, an appropriate mixing ratio of PTFE powder, De-NOx catalyst, and lubricant is also important during the production of catalyst fibers, but additional detailed working conditions are also required in the mixing process.

[0044] In addition, the mixer is mixed while repeating alternating drops using gravity and centrifugal force. However, if the mixing speed is too fast, aggregation of PTFE powder will occur, and the De-NOx catalyst cannot be properly mixed.

[0045] Since PTFE powder and the De-NOx catalyst do not melt even at quite high temperatures and are physically stable, they have physical properties that prevent them from chemically / physically bonding to each other. Therefore, the role of the lubricant in the mixing process is very important.

[0046] Simply putting the lubricant into the mixer together and mixing it cannot achieve uniform mixing. Therefore, how to mix the lubricant in the mixing process is also a very important factor.

[0047] The lubricant is uniformly injected into the two powder mixtures (PTFE, De-NOx catalyst) through the inlet of the rotating mixer for mixing. At this time, the injection rate of the lubricant must be adjusted to prevent too much lubricant from being injected. If the injection amount is too large, the lubricant may aggregate in some parts and uniform mixing may not be achieved.

[0048] The lubricant must be injected only into the two powder mixtures and should be adjusted so that it is not injected onto the wall of the mixer. When injected onto the wall of the mixer, the two powder mixtures may stick to the wall of the mixer and cannot be removed, resulting in losses and non-uniform mixing.

[0049] The De-NOx effect increases as the content of the De-NOx catalyst increases. However, in the mixing process, as the amount of the De-NOx catalyst increases, the amount of the lubricant must also increase, and only when the mixing time increases can the dispersibility, workability, and productivity of the catalyst be improved.

[0050] Reflecting such conditions, experiments were conducted as follows.

[0051] The conditions applied to the above experiments are as follows.

[0052] In the present invention, sintering is carried out within the temperature range of 300°C to 500°C, and specifically, it is preferably carried out at around 400°C. However, in the present invention, rather than the conditions of the sintering temperature, emphasis is placed on the ratio of the catalyst, the ratio of the lubricant, the injection rate of the lubricant, the mixing rate, and the mixing time used in the mixing process.

[0053] Whether the homogenization operation is performed well is judged based on the degree of blending of the lubricant, PTFE, and catalyst. According to an embodiment of the present invention, a specific judgment on the degree of blending is made by checking the blending ratio or color of the mixed powder.

[0054] In the present invention, the homogenization grade is classified dichotomously into a blending ratio analysis evaluation and an operator evaluation. More specifically, points are given to the analysis results of the blending ratio of the sample, and the grades are classified into 'excellent', 'good', and 'insufficient' by averaging with the evaluation points of the operator.

[0055] This is to complement the change in the blending ratio due to vibration during the process of sampling the sample for the analysis of the blending ratio.

[0056] The analysis of the blending ratio of the sample is carried out as follows.

[0057] When analyzing the blending ratio of the sample, if the blending ratio is 80% or more, the homogenization grade is evaluated as 'excellent'. If the blending ratio is 50% or more and less than 80%, the homogenization grade is evaluated as 'good'. If the blending ratio is less than 50%, the homogenization grade is evaluated as 'insufficient'.

[0058] When the homogenization grade is 'excellent', 3 points are given. When the homogenization grade is 'good', 2 points are given. When the homogenization grade is 'insufficient', 1 point is given.

[0059] The operator evaluation of the sample is carried out as follows.

[0060] First, for the operator evaluation, 20 operators involved in the production of the product are selected.

[0061] After that, show the selected operator the mixed powder before sample collection.

[0062] Each operator assigns 3 points if they determine that the formulation of the mixed powder is excellent, 2 points if they determine that the formulation is good, and 1 point if they determine that the formulation is insufficient. The average of the points assigned by each operator is used to classify the homogenization grade of the mixed powder.

[0063] For consistent evaluation, the following criteria were presented to the operators.

[0064] First, show the operators samples with mixing ratios of 90%, 60%, and 30%.

[0065] Then, if the operator determines that the mixing ratio is 80% or more and no agglomerated parts are seen when looking at the color of the powder, 3 points are assigned. If the operator determines that the mixing ratio is 50% or more and less than 80%, and 1 - 2 agglomerated parts are seen when looking at the color of the powder, 2 points are assigned. If the operator determines that the mixing ratio is less than 50% and 3 or more agglomerated parts are seen when looking at the color of the powder, 1 point is assigned.

[0066] At the time of operator evaluation, 3 points mean 'excellent', 2 points mean 'good', and 1 point means 'insufficient'.

[0067] Calculate the final evaluation score by averaging the score calculated through the analysis of the mixing ratio and the average score of the operator calculated through the operator evaluation.

[0068] Round the final evaluation score. Determine that a score of 3 means the homogenization grade is 'excellent', a score of 2 means the homogenization grade is 'good', and a score of 1 means the homogenization grade is 'insufficient'.

[0069] It is determined that the factors having the greatest influence on the homogenization grade are the mixing speed (rpm) and the mixing time (min).

[0070] Therefore, in order to confirm how to adjust the conditions of the mixing speed and mixing time, the homogenization grades were judged by varying the mixing time and mixing speed as shown in Table 2 below.

[0071] Table 2 is a table showing the evaluation criteria for the homogenization grade in the present invention.

[0072]

Table 2

[0073] According to Table 2, when the mixing speed is 20 rpm, it can be confirmed that the homogenization grade is 'insufficient' regardless of the mixing time.

[0074] When the mixing speed was lowered to 18 rpm and the mixing time was 60 min, the homogenization grade was confirmed to be 'good'.

[0075] When the mixing speed was lowered to 16 rpm and the mixing time was 60 min, the homogenization grade was confirmed to be 'excellent'.

[0076] When the mixing speed was lowered to 14 rpm, when the mixing time was 60 min to 50 min, the homogenization grade was confirmed to be 'excellent'.

[0077] When the mixing speed is 14 rpm and the mixing time is 40 min, the homogenization grade was confirmed to be 'good'.

[0078] However, when the mixing speed was 14 rpm and the mixing time was shortened to 30 min, it was confirmed that the homogenization grade was 'insufficient'.

[0079] That is, it can be confirmed that the lower the mixing speed, the higher the homogenization grade tends to be, but when the mixing time is lowered to 30 min or less, the homogenization grade becomes low even if the mixing speed is low.

[0080] When the homogenization grade of the powder is high, the performance of the catalyst fiber should improve. Therefore, in the experiment of the catalyst fiber (or the PTFE membrane filter using the same), the mixing speed is set to 20 rpm or less, and the mixing time is set to 60 min.

[0081] The experiment of the PTFE membrane catalyst filter was carried out based on the desorption rate of the catalyst, workability, productivity, De-NOx efficiency, and dispersibility of the catalyst.

[0082] The desorption rate of the catalyst was measured in the range of 20% to 50%. When the desorption rate of the catalyst exceeds 50% during the measurement of the result value, since the desorption rate is excessive, it is difficult to commercialize, and therefore, it is meaningless to measure the accurate value. Thus, when the desorption rate of the catalyst exceeds 50%, it is indicated as 50%. Similarly, when the desorption rate of the catalyst is 20% or less, since it is sufficient for commercialization, it is meaningless to measure the accurate value. Therefore, when the desorption rate of the catalyst is less than 20%, it is indicated as 20%.

[0083] Productivity was classified into 'excellent', 'good', and 'insufficient'.

[0084] In the present invention, the classification of the productivity grade is based on the frequency of occurrence of errors.

[0085] Errors occurring in the production process are judged based on whether the following three phenomena occur. 1) 'Occurrence of cracks in billets' 2) 'Occurrence of holes on the sheet' 3) 'Occurrence of cracks in rods'

[0086] If necessary, 'instability of the uniformity of the sheet thickness', 'intensity of the sheet', etc. can also be included in the criteria for error judgment.

[0087] When evaluating according to the above criteria, if no errors occur in the production process, the productivity is evaluated as 'excellent'. If errors occur more than 0 times and less than 2 times in the production process, the productivity is evaluated as 'good'. If errors occur 2 times or more in the production process, the productivity is evaluated as 'insufficient'.

[0088] If productivity is based on the number of defects occurring in product production, workability is based on the number of production process interruptions.

[0089] Specifically, workability is classified into 'excellent', 'good', and 'insufficient' based on the number of times the production process stops due to breakage occurring in the slitting process.

[0090] In the evaluation of workability, when working with a total of 10 kg of PTFE mixed powder, check how many times breakage occurs. It is calculated that the workability decreases by 5% each time breakage occurs once.

[0091] Table 3 is a table summarizing the evaluation criteria for the workability of the present invention.

[0092]

Table 3

[0093] Referring to Table 3, when the workability is 90% or more (when breakage occurs 2 times or less), the workability is evaluated as 'excellent'. When the workability is less than 90% and 75% or more (when breakage occurs more than 2 times and 5 times or less), the workability is evaluated as 'good'.

[0094] When the workability is less than 75% (when breakage occurs more than 5 times), the workability is evaluated as 'insufficient'.

[0095] When the workability is evaluated as 'insufficient', since it is impossible to proceed with the process further, it is necessary to change the conditions.

[0096] The dispersibility of the catalyst indicates whether the catalyst is uniformly distributed on the surface of the non-woven fabric when the non-woven fabric is produced using the PTFE fibers manufactured according to the present invention.

[0097] The evaluation of the dispersibility is performed by observing five arbitrary spots on the non-woven fabric sample with an optical microscope.

[0098] When the aggregation of the catalyst is observed less than three times as a result of observing the five arbitrary spots, it is evaluated that the dispersibility is 'excellent'.

[0099] When the aggregation of the catalyst is observed three or more times and less than six times as a result of observing the five arbitrary spots, it is evaluated that the dispersibility is 'good'.

[0100] When the aggregation of the catalyst is observed six or more times as a result of observing the five arbitrary spots, it is evaluated that the dispersibility is 'insufficient'.

[0101] The De-NOx filtration efficiency was measured based on the Modified BS EN 1822-3 test method.

[0102] The filter fiber has a filtration efficiency of 99.9% or more for 0.3 μm particles at 32 LPM, and at this time, the pressure loss is 100 mmAq or less. The catalyst filter finally produced by manufacturing a non-woven fabric with such catalyst fibers and compositing a PTFE membrane has an air permeability of 3 cm 3 / cm 2 .s or more.

[0103] When the De-NOx efficiency is 7% or more, it is evaluated as 'excellent'. When the De-NOx efficiency is 3% or more and less than 5%, it is evaluated as 'ordinary'. When the De-NOx efficiency is less than 3%, it is evaluated as 'bad'.

[0104] When showing the experimental results according to the above-mentioned criteria, it is as shown in Table 4 below.

[0105] [Table 4]

[0106] Looking at Table 4 above, it is possible to confirm how the characteristics of the PTFE catalyst fiber change by adjusting the ratio of the catalyst, the degree of homogenization operation (mixing speed and mixing time), the ratio of the lubricant, and the injection speed of the lubricant in the mixing process.

[0107] In the above table, since it is impossible to produce fibers, '-' is indicated when measurement is impossible.

[0108] In Samples 1 to 3, the ratio of the catalyst in the mixing process was fixed at 0.3%, the ratio of the lubricant was fixed at 25%, the injection speed of the lubricant was fixed at 250 g / min, and the degree of blending (homogenization grade) was changed.

[0109] Referring to Table 2 and Table 4, in the case of Sample 1, the mixing speed is 20 rpm and the mixing time is 30 min. Under such conditions, the homogenization grade is confirmed to be 'insufficient'.

[0110] In the case of Sample 1, the catalyst desorption rate was 50%, the workability was 'insufficient', the productivity was 'low', the De-NOx efficiency was 'bad', and the catalyst dispersibility was 'low'. According to this, it was confirmed that there is a problem in commercializing the product because the catalyst dispersibility decreases and the activity of the catalyst (De-NOx efficiency) is very low.

[0111] Figure 11A is a photograph showing the billet of Sample 1, and Figure 11B is a photograph showing the rolled sheet of Sample 1.

[0112] Referring to Figures 11A and 11B, in the case of Sample 1, it can be confirmed that thin stripes are formed in the billet due to catalyst aggregation. This is considered to be due to the fact that the catalyst is not uniformly dispersed and thus aggregated. Also, the catalyst is aggregated in thick spot shapes on the sheet, and the catalyst desorption rate is high during the production of the fiber, resulting in a break phenomenon.

[0113] In the case of Sample 2, the mixing speed is 20 rpm and the mixing time is 60 min. Under such conditions, the homogenization grade is confirmed to be 'insufficient'.

[0114] In the case of Sample 2, the catalyst desorption rate was 45%, workability was 'insufficient', productivity was 'low', De-NOx efficiency was 'poor', and catalyst dispersibility was'medium'. It was confirmed that although the catalyst desorption rate and catalyst dispersibility of Sample 2 were better than those of Sample 1, there was still a problem in commercialization because the catalyst activity was low.

[0115] Figure 12A is a photograph showing the billet of Sample 2, and Figure 12B is a photograph showing the rolled sheet of Sample 2.

[0116] Referring to Figures 12A and 12B, as a result of conducting experiments by increasing the mixing time of the lubricant, it was confirmed that the aggregation phenomenon and breakage phenomenon of the catalyst were partially improved. However, due to the low activity of the catalyst, it is difficult to commercialize.

[0117] In the case of Sample 3, the mixing speed is 18 rpm and the mixing time is 60 min. Under such conditions, the homogenization grade is confirmed to be 'good'.

[0118] In the case of Sample 3, the catalyst desorption rate was 40%, workability was 'good', productivity was'medium', De-NOx efficiency was 'poor', and catalyst dispersibility was'medium'. It was confirmed that although the catalyst desorption rate, workability, and productivity of Sample 3 were better than those of Sample 2, there was still a problem in commercialization because the catalyst activity was low.

[0119] Figure 13A is a photograph showing the billet of Sample 3, and Figure 13B is a photograph showing the rolled sheet of Sample 3.

[0120] Referring to this, when raising the homogenization grade of the catalyst, it can be confirmed that the phenomenon of catalyst aggregation is improved compared to Samples 1 and 2. Through this, it can be understood that the homogenization of the catalyst affects productivity.

[0121] For Sample 4, the mixing speed is 16 rpm and the mixing time is 60 min. Under such conditions, the homogenization grade is confirmed to be 'excellent'.

[0122] For Sample 4, the catalyst desorption rate was 40%, the workability was 'good', the productivity was'medium', the De-NOx efficiency was 'bad', and the catalyst dispersibility was'medium'. It was confirmed that the results of Sample 4 were not much different from those of Sample 3. That is, it was confirmed that Sample 4 still had problems in commercialization due to the low activity of the catalyst.

[0123] Figure 14A is a photograph showing the billet of Sample 4, and Figure 14B is a photograph showing the rolled sheet of Sample 4. Referring to these, it can be confirmed that when the mixing speed is decreased to increase the homogenization grade of the catalyst, the catalyst aggregation phenomenon of the billet and the sheet is further improved.

[0124] In Sample 5, other conditions were the same as those in Sample 4, and the ratio of the catalyst in the mixing process was increased by about 33% from 0.3% to 0.4%.

[0125] For Sample 5, the catalyst desorption rate was 40%, the workability was 'good', the productivity was'medium', the De-NOx efficiency was 'bad', and the catalyst dispersibility was'medium'. It was confirmed that the results of Sample 5 were not much different from those of Sample 4. That is, it was confirmed that Sample 5 still had problems in commercialization due to the low activity of the catalyst.

[0126] In Sample 6, other conditions were the same as those in Sample 5, and the mixing speed was decreased to 14 rpm.

[0127] In the case of Sample 6, the catalyst desorption rate was 40%, workability was 'good', productivity was'medium', De-NOx efficiency was 'bad', and the catalyst dispersibility was 'high'. In Sample 6, although the catalyst dispersibility improved, it was confirmed that there was not much difference from Sample 5 in other result values. It was also confirmed that Sample 6 still had a problem in commercialization because the catalyst activity was low.

[0128] In Sample 7, the ratios of the catalyst and the lubricant in Sample 6 were changed. The ratio of the catalyst was increased from 0.4% to 0.5%, and the ratio of the lubricant was increased from 25% to 26%.

[0129] Looking at the results, in the case of Sample 7, the catalyst desorption rate was 30%, workability was 'good', productivity was 'high', De-NOx efficiency was 'ordinary', and the catalyst dispersibility was'medium'. According to the results of Sample 7, it was confirmed that the catalyst activity became moderately good, but the activity was still insufficient for commercialization, and the catalyst dispersibility decreased. Also, problems such as the occurrence of holes in the sheet were confirmed.

[0130] Also, referring to Figure 15, in Sample 7, it was confirmed that a large amount of the catalyst was desorbed during the slitting process.

[0131] In Sample 8, experiments were conducted under the conditions of a catalyst ratio of 0.5%, a lubricant ratio of 28%, a lubricant injection rate of 200 g / min, a mixing speed of 12 rpm, and a mixing time of 30 min.

[0132] Looking at the results, in the case of Sample 8, the catalyst desorption rate was 20%, workability was 'good', productivity was'medium', De-NOx efficiency was 'ordinary', and the catalyst dispersibility was 'low'. In the case of Sample 8, it was judged that it was difficult to commercialize because the catalyst was unevenly distributed and the activity was low.

[0133] Referring to Figure 16, in Sample 8, it was confirmed that the desorption of the catalyst was significantly reduced compared to Sample 7.

[0134] In Sample 9, the experiment was conducted with a longer mixing time than in Sample 8. Specifically, in Sample 9, the catalyst ratio was 0.5%, the lubricant ratio was 28%, the lubricant injection rate was 250 g / min, the mixing speed was 12 rpm, and the mixing time was 60 min.

[0135] Upon checking the results, in the case of Sample 9, the catalyst desorption rate was 20%, the workability was 'insufficient', the productivity was'medium', the De-NOx efficiency was 'ordinary', and the catalyst dispersibility was'medium'. In the case of Sample 9, it was confirmed that the workability decreased and it was difficult to produce the product. Specifically, problems occurred with the billet and rod, and it was confirmed that there were problems in mass-producing the product.

[0136] Figure 17A is a photograph showing the billet of Sample 9, and Figure 17B is a photograph showing the rolled sheet of Sample 9.

[0137] Referring to Figures 17A and 17B, it was also confirmed that the phenomenon of the billet cracking occurred and fine holes were formed during the process of sintering / stretching the sheet.

[0138] In Sample 10, the catalyst ratio was 0.5%, the lubricant ratio was 28%, the lubricant injection rate was 200 g / min, the mixing speed was 12 rpm, and the mixing time was 60 min.

[0139] Upon checking the results, in the case of Sample 10, the catalyst desorption rate was 20%, the workability was 'excellent', the productivity was 'high', the De-NOx efficiency was 'excellent', and the catalyst dispersibility was 'high'. As a result of the experiment, it was confirmed that the characteristics to be measured were overall excellent and there were no problems in mass-producing the product.

[0140] Figure 18 is a photograph showing the billet of Sample 10.

[0141] Referring to Figure 18, as a result of conducting the experiment with the lubricant injection rate decreased, it was confirmed that the cracking phenomenon in the billet was improved and the productivity was enhanced.

[0142] In Sample 11, the ratio of the catalyst was 0.5%, the ratio of the lubricant was 28%, the injection rate of the lubricant was 220 g / min, the mixing speed was 13 rpm, and the mixing time was 60 min.

[0143] Upon checking the results, in the case of Sample 11, the desorption rate of the catalyst was 20%, the workability was 'good', the productivity was 'high', the De-NOx efficiency was 'excellent', and the dispersibility of the catalyst was 'high'. As a result of conducting experiments with slightly varying the injection rate and mixing speed of the lubricant in Sample 10, it was confirmed that although the workability of Sample 11 was slightly lower than that of Sample 10, it was judged to be in the 'good' grade and there were no problems with mass production of the product.

[0144] In Sample 12, the ratio of the catalyst was 0.6%, the ratio of the lubricant was 29%, the injection rate of the lubricant was 180 g / min, the mixing speed was 13 rpm, and the mixing time was 60 min.

[0145] Upon checking the results, in the case of Sample 12, the desorption rate of the catalyst was 20%, the workability was 'good', the productivity was 'high', the De-NOx efficiency was 'excellent', and the dispersibility of the catalyst was 'high'. Although the workability of Sample 12 was slightly lower than that of Sample 10, it was judged to be in the 'good' grade and it was confirmed that there were no problems with mass production of the product.

[0146] That is, it can be confirmed that Samples 10 to 12 are all conditions suitable for mass production of the product, but the conditions of Sample 10 are better than those of Sample 11 and Sample 12.

[0147] In Sample 13, in Sample 10, other conditions were fixed and the ratio of the catalyst was increased. That is, the conditions of Sample 13 were a catalyst ratio of 0.7%, a lubricant ratio of 28%, a lubricant injection rate of 200 g / min, a mixing speed of 12 rpm, and a mixing time of 60 min.

[0148] Upon checking the results, in the case of Sample 13, the catalyst desorption rate was 30%, workability was 'insufficient', productivity was 'low', De-NOx efficiency was 'ordinary', and catalyst dispersibility was 'low'. From the experimental results of Sample 13, when the ratio of the catalyst was increased to 0.7% or more, the catalyst desorption rate increased, and it was confirmed that there were multiple breakages during the production process of the fiber, indicating problems in product production.

[0149] From the results of Sample 13, it was confirmed that workability and productivity were extremely low, which could be due to fixing the ratio of the lubricant and only increasing the ratio of the catalyst. Also, it might be because the powder was not homogeneously mixed. Therefore, in Samples 14 and 15, the ratio of the lubricant and the mixing speed were changed.

[0150] The conditions for Sample 14 were a catalyst ratio of 0.7%, a lubricant ratio of 29%, a lubricant injection speed of 200 g / min, a mixing speed of 16 rpm, and a mixing time of 60 min.

[0151] Upon checking the results, in the case of Sample 14, the catalyst desorption rate was 25%, workability was 'insufficient', productivity was 'low', De-NOx efficiency was 'excellent', and catalyst dispersibility was'medium'. In the case of Sample 14, the denitrification performance was excellent, but it was confirmed that the frequency of breakage was high.

[0152] In Sample 15, the ratio of the lubricant was further increased and the mixing speed was decreased.

[0153] Specifically, the conditions for Sample 15 were a catalyst ratio of 0.7%, a lubricant ratio of 30%, a lubricant injection speed of 200 g / min, a mixing speed of 8 rpm, and a mixing time of 60 min.

[0154] Upon checking the results, in the case of Sample 15, the catalyst desorption rate was 20%, workability was 'good', productivity was'medium', De-NOx efficiency was 'excellent', and catalyst dispersibility was'medium'. In the case of Sample 15, the denitrification performance was excellent, but it was confirmed that productivity was low.

[0155] In Samples 16 to 19, the range of the injection rate of the lubricant (Samples 16 and 17) and the range of the ratio of the lubricant (Samples 18 and 19) were confirmed based on the conditions of Sample 10, which is a preferred embodiment.

[0156] In Sample 16, other conditions were the same as those of Sample 10, and the injection rate of the lubricant was increased to 270 g / min.

[0157] As a result of checking, in the case of Sample 16, the catalyst desorption rate was 20%, the workability was 'insufficient', the productivity was 'low', the De-NOx efficiency was 'bad', and the catalyst dispersibility was 'low'. It was confirmed that when the injection rate of the lubricant exceeds 270 g / min, the dispersibility decreases, the workability and productivity also become low, and it is difficult to mass-produce the product.

[0158] In Sample 17, other conditions were the same as those of Sample 10, and the injection rate of the lubricant was decreased to 130 g / min.

[0159] As a result of checking, in the case of Sample 17, the catalyst desorption rate was 20%, the workability was 'good', the productivity was'medium', the De-NOx efficiency was 'bad', and the catalyst dispersibility was 'low'. When the injection rate of the lubricant is less than 130 g / min, the aggregation phenomenon of the catalyst occurs, and problems such as holes in the sheet or tearing of the sheet occur due to the aggregated catalyst.

[0160] In Sample 18, other conditions were the same as those of Sample 10, and the ratio of the lubricant was decreased to 25%.

[0161] As a result of checking, in the case of Sample 18, the catalyst desorption rate was 25%, the workability was 'insufficient', the productivity was 'low', the De-NOx efficiency was 'bad', and the catalyst dispersibility was 'low'. It was confirmed that when the ratio of the lubricant is less than 25%, the sheet becomes hard and it is difficult to adjust the thickness.

[0162] In Sample 19, other conditions were the same as those of Sample 10, and the ratio of the lubricant was increased to 35%.

[0163] In this case, it was confirmed that production was impossible and the possibility of a fire occurring was high. When the lubricant is increased by 35% or more, safety problems may occur.

[0164] According to at least one of the embodiments described above, in the present invention, by applying a PTFE membrane to filter dust in the exhaust gas on the surface of the filter and removing nitrogen oxides by reacting NOx in a bag filter loaded with a catalyst, NOx and dust can be removed simultaneously. In addition, it becomes possible to manufacture a catalyst filter using a catalyst fiber method instead of a coating method catalyst filter that depends on overseas technical capabilities and products.

[0165] The embodiments described in this specification and the accompanying drawings only exemplarily explain a part of the technical idea included in the present invention. Therefore, the embodiments disclosed in this specification are not for limiting the technical idea of the present invention, but for explanation. It is obvious that the scope of the technical idea of the present invention is not limited by such embodiments. Any variations and specific embodiments that can be easily inferred by those skilled in the art within the scope of the technical idea included in the specification and drawings of the present invention should be construed as being included in the scope of the rights of the present invention.

Claims

1. A method for mixing powders for manufacturing PTFE fibers, which involves mixing a De-NOx catalyst and a lubricant with PTFE powder, in the process of putting PTFE powder and De-NOx catalyst powder into a mixer that repeatedly drops and mixes the powders using gravity and centrifugal force and rotating them, injecting a lubricant into the powders to produce a mixed powder, wherein the lubricant is adjusted to be injected only into the PTFE powder and the De-NOx catalyst powder and not onto the wall surface of the mixer, the De-NOx catalyst powder is 0.5 wt% or more and less than 0.7 wt% of the total weight, the lubricant is 27 wt% or more and 29 wt% or less of the total weight, the injection speed of the lubricant is 150 g / min or more and less than 250 g / min, the rotation speed of the mixer is 10 rpm or more and 14 rpm or less, and the mixing time is 40 minutes or more and 70 minutes or less. A method for mixing powders for manufacturing PTFE fibers, characterized by the above.

2. A method for manufacturing PTFE fibers for manufacturing a PTFE membrane catalyst filter, which is manufactured through a mixing process, an aging process, a compression process, an extrusion process, a rolling process, a sintering process, a string making / drawing process, and a slitting process, wherein the mixing process in the process of putting PTFE powder and De-NOx catalyst powder into a mixer that repeatedly drops and mixes the powders using gravity and centrifugal force and rotating them, injecting a lubricant into the powders to produce a mixed powder, the lubricant is adjusted to be injected only into the PTFE powder and the De-NOx catalyst powder and not onto the wall surface of the mixer, the De-NOx catalyst powder is 0.5 wt% or more and less than 0.7 wt% of the total weight, the lubricant is 27 wt% or more and 29 wt% or less of the total weight, the injection speed of the lubricant is 150 g / min or more and less than 250 g / min, the rotation speed of the mixer is 10 rpm or more and 14 rpm or less, and the mixing time is 40 minutes or more and 70 minutes or less. A method for manufacturing PTFE fibers, characterized by the above.

3. A method for manufacturing a PTFE membrane catalyst filter using PTFE fibers manufactured through a mixing process, an aging process, a compression process, an extrusion process, a rolling process, a sintering process, a string making / drawing process, and a slitting process, wherein the mixing process In the process of putting PTFE powder and De-NOx catalyst powder into a mixer that repeatedly drops and mixes using gravity and centrifugal force and rotating them, a lubricant is injected into the powder to generate a mixed powder. The lubricant is adjusted to be injected only onto the PTFE powder and the De-NOx catalyst powder and not onto the wall surface of the mixer. The De-NOx catalyst powder is 0.5% by weight or more and less than 0.7% by weight of the total weight, The lubricant is 27% by weight or more and 29% by weight or less of the total weight, The injection rate of the lubricant is 150 g / min or more and less than 250 g / min, The rotation speed of the mixer is 10 rpm or more and 14 rpm or less, and the mixing time is 40 minutes or more and 70 minutes or less. A method for manufacturing a PTFE membrane catalyst filter, characterized by this.

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