A method of simulating the efficiency of a filter in trapping particulate matter from smoke

Abstract

The application provides a method for simulating evaluation of filter on particulate matter trapping efficiency of smoke, which comprises the following steps: firstly, extracting particulate matter from smoke generated after smoking of a batch of conventional cigarettes by using a Cambridge filter, and preparing a suspension after treatment for standby, and then preparing aerosol particles by using an aerosol generating device; then taking a new Cambridge filter and a filter rod to be tested, recording initial mass, and then making the aerosol particles by using a smoking machine, so that the aerosol particles are trapped, and then recording the mass after trapping, and then recording the mass of captured water and ethanol by using gas chromatography, and finally obtaining the trapping efficiency by conversion operation of the mass. The method has the advantages of consistency of chemical components and aerosol particles with real cigarette smoke, simple and efficient and accurate evaluation link.

Description

Technical Field

[0001] This invention relates to the field of cigarette filter retention, and more specifically, to a method for simulating and evaluating the retention efficiency of filters for particulate matter in cigarette smoke. Background Technology

[0002] Cigarette filters can effectively remove some harmful components from cigarette smoke, reducing the harm caused by smoking to the human body. They are currently the most widely used method for reducing tar in cigarettes, and therefore the research and development of special filters has received widespread attention and application.

[0003] There are many types of cigarette filters, including cellulose acetate filters, polypropylene filters, paper filters, and special filters. Studying the retention behavior of filters in cigarette smoke is of great value for cigarette design.

[0004] One of the main indicators for evaluating the filtration effect of cigarette filters is the amount of harmful components they can retain. Therefore, research on the retention efficiency of different cigarette filters for harmful components is particularly important.

[0005] In the development of new filter tips, evaluating the filtration rate of the filter tip usually requires conducting cigarette tests in the cigarette manufacturing workshop and then using the tested cigarettes as a standard for evaluation. This process is lengthy and costly.

[0006] For example, application number CN201310692011.6, entitled "A method for determining the tar retention efficiency and tar retention amount in cigarette filters"; and CN201711465802.X, entitled "A method for detecting the retention efficiency of filters for harmful components in cigarette smoke", are both methods used to test cigarette filters and can only be considered part of workshop cigarette testing.

[0007] Therefore, establishing a simulation evaluation method for filter rate is of great application value for cigarette filter development.

[0008] In order to solve the above problems, people have been seeking an ideal technological solution. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for simulating and evaluating the retention efficiency of filter tip for particulate matter in cigarette smoke that is consistent with the chemical composition and aerosol particles of real cigarette smoke, and is simple, efficient and accurate in the entire evaluation process.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is: a method for simulating and evaluating the retention efficiency of filter tips for particulate matter in flue gas, comprising the following steps:

[0011] Step 1) Use Cambridge filters to capture particulate matter in the smoke produced after smoking a batch of regular cigarettes;

[0012] Step 2) Place the Cambridge filter that captures particulate matter into an ethanol solution, soak, crush, and filter out the material of the Cambridge filter itself to obtain a suspension containing only particulate matter from cigarette smoke, for later use;

[0013] Step 3) Take a new Cambridge filter, weigh it, and install it in a single-channel smoking machine. Record the mass of the Cambridge filter as m1. Weigh the filter rod of the set length and insert it into the trap of the single-channel smoking machine. Record the mass of the filter rod as m2.

[0014] Step 4) Pour an appropriate amount of the suspension prepared in Step 2) into the aerosol generator to generate a stable aerosol. The outlet of the aerosol generator is sealed and connected to the inlet of the single-channel smoking machine. Suck in the standard suction mode and set the number of suctions and frequency.

[0015] Step 5) After the aspiration is completed, remove the Cambridge filter and the filter rod to be tested, and weigh them separately. The mass of the Cambridge filter that traps aerosol particles is recorded as m3, and the mass of the filter rod to be tested that traps aerosol particles is recorded as m4.

[0016] Step 6) Use gas chromatography to determine the contents of ethanol and water in the Cambridge filter and the test filter tip respectively. Record the mass of ethanol in the Cambridge filter as m5, the mass of ethanol in the test filter tip as m6, the mass of water in the Cambridge filter as m7, and the mass of water in the test filter tip as m8.

[0017] Step 7) Calculate the filter retention efficiency using the following formula:

[0018] η=(m4-m2-m6-m8) / (m4-m2-m6-m8+m3-m1-m5-m7)x100%.

[0019] Based on the above, in step 2), 100 ml of 50-95% ethanol solution is used, the soaking time is at least 20 hours, and the filter screen used for filtration is at least 100 mesh.

[0020] Based on the above, in step 3), the length of the filter rod to be tested is set to 25-40mm.

[0021] Based on the above, in step 4), the number of suctions is set to at least 6, and the interval between suction frequencies is 1 second.

[0022] Based on the above, in step 6), the filter rod containing aerosols is placed into the processing bottle, isopropanol is added, the opening is sealed, and ultrasonic extraction is performed. The extraction time is set, and the resulting extract is filtered through an organic phase filter membrane into a chromatographic bottle for analysis. The Cambridge filter containing aerosols is used to obtain an extract for analysis using the same method. Then, gas chromatography analysis is performed.

[0023] Based on the above, the treatment bottle is a 50ml conical flask, 20ml of isopropanol is added, the opening is sealed, and ultrasonic extraction is performed for 30 minutes.

[0024] Based on the above, the extract after ultrasonic extraction was filtered using a 0.22 μm organic phase filter membrane.

[0025] Based on the above, the analytical conditions for gas chromatography are as follows:

[0026] Porpak Q column, 1 / 8 inch inner diameter, 2 m; detector: TCD; injection port temperature 250°C; injection volume 2 μL; splitless; carrier gas: helium, reference gas: helium; carrier gas flow rate 20 mL / min; oven temperature 170°C, detector temperature 250°C.

[0027] This invention has outstanding substantive features and significant progress compared to the prior art. Specifically, this invention has the following advantages:

[0028] After capturing particulate matter from real cigarette smoke using Cambridge filters, the resulting suspension is used as a reference for testing the retention efficiency of other filter rods. Compared to other methods of simulating cigarette smoke aerosols, the aerosol particulate matter composition obtained by this method is basically consistent with the particulate matter composition that can be retained by aerosols from real cigarette smoke, and the size of the aerosol particles is also basically consistent with the size of the particulate matter that can be retained by aerosols from real cigarette smoke. Therefore, the experiments conducted to evaluate the retention efficiency of the filter rod under test have relatively more accurate reference value, and can even eliminate the physical verification step, thereby improving the verification efficiency of filter rod evaluation and shortening the cycle. Attached Figure Description

[0029] Figure 1 This is a particle size distribution diagram of the aerosol particles prepared in this invention.

[0030] Figure 2 This is a reference image for the gas chromatography analysis of water and ethanol mass in step 6) of the present invention. Detailed Implementation

[0031] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0032] A method for simulating and evaluating the retention efficiency of filter tips for particulate matter in flue gas includes the following steps:

[0033] Step 1) Use a Cambridge filter to capture particulate matter in the smoke produced after smoking 10-20 regular cigarettes;

[0034] Step 2) Place the Cambridge filter for capturing particulate matter into 100ml of 50-95% ethanol solution and soak for 24 hours. After high-speed crushing, filter out the material of the Cambridge filter itself using a filter screen of at least 100 mesh to obtain a suspension containing only particulate matter from cigarette smoke, which is then kept for later use.

[0035] Step 3) Take a new Cambridge filter, weigh it, and install it in a single-channel smoking machine. Record the mass of the Cambridge filter as m1. Weigh the 25-40mm long filter rod to be tested and insert it into the trap of the single-channel smoking machine. Record the mass of the filter rod as m2.

[0036] Step 4) Pour an appropriate amount of the suspension prepared in Step 2) into the aerosol generator. The outlet of the aerosol generator is sealed and connected to the inlet of the single-channel smoking machine to generate a stable aerosol. The single-channel smoking machine is used in the standard suction mode, with the number of suctions set to 6 and the suction frequency interval to 1 second.

[0037] like Figure 1 As shown, the particle size distribution of the prepared aerosol is roughly the same as that of the aerosol in real cigarette smoke, indicating that it can replace the aerosol in real cigarette smoke for analyzing filter rod performance.

[0038] Step 5) After the aspiration is completed, remove the Cambridge filter and the filter to be tested, and weigh them separately. The mass of the Cambridge filter that traps aerosol particles is recorded as m3, and the mass of the filter rod (with plastic tube) that traps aerosol particles is recorded as m4.

[0039] Step 6) The contents of ethanol and water in the Cambridge filter and the test filter tip were determined by gas chromatography. Specifically, the test filter rod containing aerosol was placed in a 50 ml Erlenmeyer flask, 20 ml of isopropanol was added, the flask was sealed, and ultrasonic extraction was performed for 30 min. The resulting extract was filtered through a 0.22 μm organic phase filter membrane into a chromatographic bottle for analysis. The Cambridge filter containing aerosol was extracted using the same method and then analyzed.

[0040] Analytical conditions for gas chromatography:

[0041] Porpak Q column, 1 / 8 inch inner diameter, 2 m; detector: TCD; injection port temperature 250°C; injection volume 2 μL; splitless; carrier gas: helium, reference gas: helium; carrier gas flow rate 20 mL / min; oven temperature 170°C, detector temperature 250°C.

[0042] like Figure 2 As shown, this is the basis for the extraction and analysis of water and ethanol. After analysis, the mass of ethanol in the Cambridge filter is recorded as m5, the mass of ethanol in the test filter tip is recorded as m6, the mass of water in the Cambridge filter is recorded as m7, and the mass of water in the test filter tip is recorded as m8.

[0043] Step 7) Calculate the filter retention efficiency using the following formula:

[0044] η=(m4-m2-m6-m8) / (m4-m2-m6-m8+m3-m1-m5-m7)x100%.

[0045] Verification Example 1

[0046] Take a regular cigarette, remove the tobacco, and keep the filter. The filter tip has a circumference of 24.1 mm, a length of 25 mm, and a weight (m2) of 0.1783 g. The Cambridge filter weighs (m1) 0.3401 g. Install the filter trap (containing the Cambridge filter) onto the smoking machine, insert the filter, and adjust the aerosol outlet of the pneumatic atomizer to a suitable position with the filter. Turn on the atomizer, and once the aerosol output is stable, turn on the smoking machine and use the standard puffing mode, taking 6 puffs with a 1-second interval. After finishing puffing, quickly remove the filter and Cambridge filter. Weigh the Cambridge filter (m3) to 0.3647 g and the filter (m4) to 0.1937 g. The detection method described in this invention was used to determine the ethanol and water content in the filter element and filter tip. The water content m8 in the filter tip was 0.0015g, the ethanol content m6 in the filter tip was 0.0030g, the water content m7 in the filter element was 0.0025g, and the ethanol content m5 in the filter tip was 0.0051g. Substituting the mass parameters into the formula, the retention efficiency of the filter tip was found to be 39.1%.

[0047] Verification Example 2:

[0048] Take a medium-sized cigarette, remove the tobacco, and keep the filter section. Its circumference is 19.8 mm, length is 30 mm, and weight is m2 (0.2256 g). The Cambridge filter weighs m1 (0.3405 g). Install the trap containing the Cambridge filter onto the smoking machine, insert the filter, adjust the aerosol outlet of the pneumatic atomizer to a suitable position with the filter, turn on the atomizer, and after the aerosol output stabilizes, turn on the smoking machine and use the standard puffing mode to take 6 puffs, with a 1-second interval between each puff. After finishing, quickly remove the filter and Cambridge filter. Weigh the Cambridge filter (m3) (0.3685 g) and the filter (m4) (0.2376 g). The detection method described in this invention was used to determine the ethanol and water content in the filter element and filter tip. The water content m8 in the filter tip was 0.0012 g, the ethanol content m6 in the filter tip was 0.0024 g, the water content m7 in the filter element was 0.0030 g, and the ethanol content m5 in the filter tip was 0.0058 g. Substituting these mass parameters into the formula, the retention efficiency of the filter tip was found to be 30.4%.

[0049] Verification Example 3:

[0050] Take a slim cigarette, remove the tobacco, and keep the filter section. The filter tip has a circumference of 17mm, a length of 30mm, and a weight (m2) of 0.1227g. The Cambridge filter weighs (m1) 0.3398g. Install the filter trap (containing the Cambridge filter) onto the smoking machine, insert the filter, and adjust the aerosol outlet of the pneumatic atomizer to a suitable position relative to the filter. Turn on the atomizer and wait for the aerosol output to stabilize. Then turn on the smoking machine and use the standard puffing mode, taking 6 puffs with a 1-second interval. After finishing puffing, quickly remove the filter and Cambridge filter. Weigh the Cambridge filter (m3) to 0.3694g and the filter (m4) to 0.1331g. The detection method described in this invention was used to determine the ethanol and water content in the filter element and filter tip. The water content m8 in the filter tip was 0.0011 g, the ethanol content m6 in the filter tip was 0.0021 g, the water content m7 in the filter element was 0.0030 g, and the ethanol content m5 in the filter tip was 0.0062 g. Substituting these mass parameters into the formula, the retention efficiency of the filter tip was found to be 25.8%.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for simulating and evaluating the retention efficiency of filter tips for particulate matter in flue gas, characterized in that: Includes the following steps: Step 1) Use Cambridge filters to capture particulate matter in the smoke produced after smoking a batch of regular cigarettes; Step 2) Place the Cambridge filter that captures particulate matter into an ethanol solution, soak, crush, and filter out the material of the Cambridge filter itself to obtain a suspension containing only particulate matter from cigarette smoke, for later use; Step 3) Take a new Cambridge filter, weigh it, and install it in a single-channel smoking machine. Record the mass of the Cambridge filter as m1. Weigh the filter rod of the set length and insert it into the trap of the single-channel smoking machine. Record the mass of the filter rod as m2. Step 4) Pour an appropriate amount of the suspension prepared in Step 2) into the aerosol generator to generate a stable aerosol. The outlet of the aerosol generator is sealed and connected to the inlet of the single-channel smoking machine. Suck in the standard suction mode and set the number of suctions and frequency. Step 5) After the aspiration is completed, remove the Cambridge filter and the filter rod to be tested, and weigh them separately. The mass of the Cambridge filter that traps aerosol particles is recorded as m3, and the mass of the filter rod to be tested that traps aerosol particles is recorded as m4. Step 6) Use gas chromatography to determine the contents of ethanol and water in the Cambridge filter and the test filter tip respectively. Record the mass of ethanol in the Cambridge filter as m5, the mass of ethanol in the test filter tip as m6, the mass of water in the Cambridge filter as m7, and the mass of water in the test filter tip as m8. Step 7) Calculate the filter retention efficiency using the following formula: η=(m4-m2-m6-m8) / (m4-m2-m6-m8+m3-m1-m5-m7)x100%.

2. The method for simulating and evaluating the retention efficiency of a filter tip for particulate matter in flue gas according to claim 1, characterized in that: In step 2), 100 ml of 50-95% ethanol solution is used, the soaking time is at least 20 hours, and the filter screen used for filtration is at least 100 mesh.

3. The method for simulating and evaluating the retention efficiency of a filter tip for particulate matter in flue gas according to claim 1 or 2, characterized in that: In step 3), the length of the filter rod to be tested is set to 25-40mm.

4. The method for simulating and evaluating the retention efficiency of a filter tip for particulate matter in flue gas according to claim 3, characterized in that: In step 4), the number of suctions is set to at least 6, and the interval between suction frequencies is 1 second.

5. The method for simulating and evaluating the retention efficiency of a filter tip for particulate matter in flue gas according to claim 1, 2, or 4, characterized in that: In step 6), the filter rod containing aerosols is placed into the processing bottle, isopropanol is added, the bottle is sealed, and ultrasonic extraction is performed. The extraction time is set, and the resulting extract is filtered through an organic phase filter membrane into a chromatographic bottle for analysis. The Cambridge filter containing aerosols is used to obtain an extract for analysis using the same method. Then, gas chromatography analysis is performed.

6. The method for simulating and evaluating the retention efficiency of a filter tip for particulate matter in flue gas according to claim 5, characterized in that: The treatment bottle is a 50ml conical flask. 20ml of isopropanol is added, the flask is sealed, and ultrasonic extraction is performed for 30 minutes.

7. The method for simulating and evaluating the retention efficiency of a filter tip for particulate matter in flue gas according to claim 5 or 6, characterized in that: The extract after ultrasonic extraction was filtered through a 0.22 μm organic phase filter membrane.

8. The method for simulating and evaluating the retention efficiency of a filter tip for particulate matter in flue gas according to claim 7, characterized in that: Analytical conditions for gas chromatography: Porpak Q column, 1 / 8 inch inner diameter, 2m; Detector: TCD; Inlet temperature: 250℃; Injection volume: 2 μL; Splitless; Carrier gas: helium; reference gas: helium; carrier gas flow rate: 20 mL / min; furnace temperature: 170℃; detector temperature: 250℃.

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