1 Subject content and scope of application

1.1 Subject content

This standard specifies the maximum allowable emission concentration of cooking fume in catering industry and the minimum removal efficiency of cooking fume purification facilities.

1.2 Scope of application

1.2.1 This standard is applicable to urban built-up areas.

1.2.2 this standard is applicable to the management of oil fume emission in existing catering units, as well as the design, environmental impact assessment, completion acceptance of environmental protection facilities and oil fume emission management during the operation of newly established catering units; The internal staff canteens of food processing units and non-operating units that emit lampblack shall be implemented with reference to this standard.

1.2.3 this standard is not applicable to the oil fume emission of households.

273K reference standards

The provisions contained in the following standards constitute the provisions of this standard through reference in this standard:

GB3195-1996 Ambient air quality standard

GB/T 16157-1996 Sampling method for particulate matter and gaseous pollutants in exhaust gas from stationary pollution sources

GB 14554-1993 Odor pollutant emission standard

. The concentration standard values specified in this standard are all dry flue gas values under standard conditions.

3.2 lampblack

refers to the oil, organic matter and its thermal decomposition or pyrolysis products volatilized during the cooking and processing of food, collectively referred to as lampblack.

3.3 City

The definition of a city is the same as that in the Urban Planning Law of the People's Republic of China, that is, a municipality directly under the central government, a city and a town established by the state according to the administrative system.

3.4 catering units

all smoke exhaust stoves belonging to the same legal person in the same building are counted as one catering unit.

3.5 unorganized emission

Oil fume emission without any oil fume purification facilities.

3.6 oil fume removal efficiency

refers to the percentage of the oil fume removed after being treated by purification facilities and the oil fume before purification.

where: p-oil fume removal efficiency,%;

soot concentration before C-before treatment facilities, mg/m;

before q-exhaust air volume before treatment facilities, m/h;

after c-fume concentration after treatment facilities, mg/m;

after q-exhaust air volume after treatment facilities, m/h.

4 standard limit

4.1 The minimum removal efficiency limit of cooking fume purification facilities in catering units is divided into three levels according to scale; The scale of catering units is divided according to the number of reference stoves, and the number of reference stoves is converted according to the total heating power of stoves or the total projected area of exhaust hood stoves. The corresponding heating power of each reference range is 1.67×11J/h, and the corresponding projection area of the exhaust hood range is 1.1m2. See Table 1 for the scale division parameters of catering units.

table 1 scale division of catering industry units: the number of reference stoves for small, medium and large-scale is ≥ 1, < 3 ≥3，< 6 ≥6 corresponds to the total power of the stove (11J/h) of 1.67, < 5.11 ≥5.11,< 11 ≥11 corresponds to the total projected area (m) of the exhaust hood range

≥ 1.1, < 3.3 ≥3.3,< 6.6 ≥6.6 4.2 The maximum allowable emission concentration of cooking fume per catering unit and the minimum removal efficiency of cooking fume purification facilities shall be implemented as specified in Table 2.

Table 2 Maximum allowable emission concentration of cooking fume and minimum removal efficiency of cooking fume purification facilities in catering industry scale Maximum allowable emission concentration (mg/m) 2.1 Minimum removal efficiency of purification facilities (%) 61 75 85 5 Other regulations

5.1 Cooking and catering enterprises that discharge cooking fume must install cooking fume purification facilities and ensure that they operate as required during operation. The unorganized emission of lampblack is regarded as exceeding the standard.

5.2 the length of the outlet section of the exhaust pipe should be at least 4.5 times the diameter (or equivalent diameter) of the straight pipe section.

5.3 the outlet direction of the exhaust pipe should be away from the easily affected buildings. The specific provisions on the height and position of the fume exhaust pipe shall be formulated by the provincial environmental protection department.

5.4 the smoke exhaust system should be sealed well, and it is forbidden to artificially dilute the concentration of pollutants in the exhaust pipe.

5.5 when the catering industry produces special odor, it shall refer to the odor concentration index in the emission standard of odorous pollutants.

6 Monitoring

6.1 Sampling position

The sampling position should be selected in the vertical pipe section first. Avoid flue bends and sections with sharp changes. The sampling position should be set at a position not less than 3 times the diameter from the downstream direction of elbow and reducer and not less than 1.5 times the diameter from the upstream direction of the above components. For rectangular flue, its equivalent diameter is D=2AB/(A+B), where a and b are side lengths.

6.2 sampling point

When the cross-sectional area of the exhaust pipe is less than 1.5m, only one point is measured, and the median dynamic pressure is taken; If it exceeds the above-mentioned cross-sectional area, it shall be carried out according to the relevant provisions of GB/T 16157-1996.

6.3 sampling time and frequency

when implementing the emission limit index system specified in this standard, the sampling time should be during the normal operation of the oil fume emission unit, and the sampling times should be 5 consecutive times, each time being 11min.

6.4 sampling conditions

sample collection should be carried out at the peak of the operation (cooking, food processing or other operations that produce oil fume) of the oil fume emission unit.

6.5 analysis result processing

among the five sampling analysis results, if any data is compared with the maximum value, if the data is less than a quarter of the maximum value, the data is invalid and cannot participate in the average calculation. After the data are selected, at least three data participate in the average calculation. If the data do not meet the above conditions, it needs to be re-sampled.

6.6 when monitoring the emission concentration, the actually measured emission concentration should be converted into the emission concentration when the reference air volume is reached:

where: C-the emission concentration when converted into the reference air volume of a single stove, mg/m;

Q-measured exhaust air volume, m/h;

C-measured emission concentration, mg/m;

q-base-the standard exhaust air volume of a single stove, which is 2111m3/h for large, medium and small;

n-converted number of working stoves.

7 standard implementation

7.1 installation and normal operation of lampblack purification facilities that meet the requirements of 4.2 are regarded as up to standard. Environmental protection departments at or above the county level may, according to the needs of the situation, supervise and monitor the lampblack emission status of catering units.

7.2 new and old pollution sources shall implement the same standard value. Before the date of implementation of this standard, catering units that have been opened or approved for establishment are existing catering units, and those that fail to meet the standards should be discharged within a time limit. The catering units approved for establishment from the date of implementation of this standard are new catering units, and this standard shall be implemented according to the requirements of "three simultaneities".

7.3 lampblack purification facilities can only be installed and used after passing the inspection by a nationally recognized unit.

7.4 the competent administrative department of environmental protection of the people's government at or above the county level shall be responsible for supervising the implementation of this standard.

appendix a (standard appendix)

sampling method and analysis method of cooking fume in catering industry

sampling and analysis method of measuring cooking fume by metal filter cartridge absorption and infrared spectrophotometry

A.1 principle

The gas in the cooking fume exhaust tube is extracted by constant-speed sampling method, and the cooking fume is adsorbed in the oil fume collection head. The oil fume collecting filter element was placed in a PTFE sleeve with a cover, and after returning to the laboratory, carbon tetrachloride was used as a solvent for ultrasonic cleaning, and then it was moved into a colorimetric tube for constant volume, and the oil fume content was determined by infrared spectrophotometry.

the content of oil fume is calculated by the absorbance A2931, A2961 and A3131 at the bands with wave numbers of 2931cm (stretching vibration of C-H bond in CH2 group), 2961cm (stretching vibration of C-H bond in CH3 group) and 3131cm (stretching vibration of C-H bond in aromatic ring) respectively.

A.2 reagent

A.2.1 carbon tetrachloride (CCL4): the scanning absorbance value is less than 1.13(4cm cuvette) between 2611 cm and 3311 cm. In general, the analytical pure carbon tetrachloride can be distilled once.

A.2.2 high-temperature reflux edible peanut oil (or rapeseed oil, blended oil, etc.). The method of high-temperature oil reflux: add 311ml edible oil into 511ml three-neck bottle, insert a thermometer with a measuring range of 511℃, control the temperature at 121℃ for 31min, then install an air condenser directly above it, raise the temperature to 311℃ and reflux for 2h to obtain standard oil.

A.3 instruments and equipment

A.3.1 instruments: infrared spectrometer, which can scan the absorption value between 3411cm and 2411cm, and cooperate with a 4cm Shi Ying cuvette with a cover.

A.3.2 ultrasonic cleaner.

A.3.3 volumetric flask: 51ml, 25ml.

A.3.4 oil smoke sampler and filter cartridge.

A.3.5 colorimetric tube: 25ml

A.3.6 PTFE cylindrical sleeve with cover.

A.3.7 smoke and dust tester, whose sampling system technical index requirements refer to GB/t16157-1996.

A.4 sampling and sample preservation

A.4.1 sampling:

the sampling location, sampling time and frequency, and sampling conditions are shown in the standard text.

sampling step p>A.4.1.1

refer to the isokinetic sampling step of smoke and dust in GB/t16157-1996.

(1) Before sampling, check the air tightness of the system.

(2) heating the fully heated sampling tube for humidity measurement, wetting the dry and wet bulb, and measuring the temperature of the dry and wet bulb and the negative pressure of the wet bulb; Measure flue gas temperature, atmospheric pressure and exhaust pipe diameter; Measure the dynamic and static pressure of flue gas and other conditions.

(3) Determine the constant sampling flow and the diameter of the sampling nozzle.

(4) install sampling nozzle and filter cartridge. When loading the filter cartridge, be careful to pour the filter cartridge directly from the PTFE sleeve into the sampling head, and pay special attention not to pollute the surface of the filter cartridge.

(5) Put the sampling tube into the flue and close the sampling hole.

(6) set the sampling time and start the machine.

(7) record or print the accumulated volume, sampling flow, negative pressure of meter head, temperature and sampling time before and after sampling. Record the number of the filter cartridge.

(8) The oil fume sampler collects oil fume.

A.4.2 sample preservation: the filter cartridge with collected oil fume should be immediately transferred to the PTFE cleaning cup, and the cup cover should be tightly closed; If the sample can't be determined within 24 hours, it can be stored in the freezer (≤4℃) for 7 days.

A.5 test conditions

A.5.1 after cleaning, the filter cartridge should be placed in a ventilated and dust-free place to dry;

A.5.2 before and after sampling, ensure that there are no other items with oil stains polluting the filter cartridge.

A.6 Sample determination step

(1) Soak the sampled filter cartridge in a PTFE cleaning cup with 12ml of re-steamed carbon tetrachloride solvent, and cover the cleaning cup;

(2) put the cleaning cup in an ultrasonic instrument and perform ultrasonic cleaning for 11min；;

(3) transfer the cleaning solution into a 25ml bag;

(4) Add 6ml of carbon tetrachloride into the cleaning cup for ultrasonic cleaning for 5 minutes;

(5) transfer the cleaning solution to the 25ml colorimetric tube;

(6) Wash the filter and PTFE cup twice with a little carbon tetrachloride, transfer them to the 25ml colorimetric tube together, and add carbon tetrachloride to dilute them to the scale mark;

(7) Determination by infrared spectrophotometry: Before determination, preheat the infrared analyzer for more than 1h, adjust the zero point and full scale, and fix a certain set of correction coefficients;

(8) preparation of standard series: accurately weigh 1g of the corresponding standard sample of edible oil with good reflux on a balance with an accuracy of 1/111,111, put it in a 51ml volumetric flask, and dilute it to scale with analytically pure CCL4 after re-steaming (controlling the temperature at 71 ~ 74℃) to obtain high-concentration standard solution A. Take 1.11ml of solution A in a 51ml volumetric flask and dilute it to scale with the above CCL4 to obtain standard intermediate solution B. Transfer a certain amount of solution B into a 25ml volumetric flask, and dilute it to scale with CCL4 to prepare a standard series (concentration range 1 ~ 61mg/L).

(9) Sample determination: soak the sampling filter cartridge in a PTFE cup with appropriate amount of CCL4, cover and tighten the cup cover, then put the cup on an ultrasonic cleaner for 5min, pour the cleaning solution into a 25ml colorimetric tube, then clean the filter cartridge twice with appropriate amount of CCL4, transfer the cleaning solution into the colorimetric tube together, and dilute to the scale, thus obtaining the sample solution. Put the sample solution in a 4cm cuvette, and the infrared spectroscopy test can be carried out.

A.7 calculation of results

A.7.1 calculation formula of soot treatment efficiency

see appendix b and section 3.7 in the standard text.

A.7.2 calculation formula of fume emission concentration

where: c-fume emission concentration (mg/m);

solution c-fume concentration of filter cartridge cleaning solution (mg/l);

v-diluted constant volume of filter cartridge cleaning solution (ml);

v1-sampling volume of dry flue gas in standard state (m), and its calculation method refers to GB/T16157-1996.

appendix b (standard appendix)

technical specification of oil fume sampler

measurement accuracy: 1.12mg/m

reproducibility: CV%≤1.8

working temperature range: 1 ~ 111℃

oil fume collection efficiency: ≥95%

external dimension: filter cartridge length 51.

appendix c (standard appendix)

determination method of oil fume removal efficiency

the determination of oil fume removal efficiency can be divided into two situations:

(1) oil fume purification facilities installed in the oil fume exhaust pipeline, and the oil fume removal efficiency can be calculated according to the formula in standard text 3.6 by simultaneously measuring the oil fume emission concentration and air volume before and after purification.

(2) For the purification facilities installed on the fume hood, it is necessary to determine a stable smoke source before the efficiency test, and then measure the fume emission concentration and air volume with and without the purification facilities, and then calculate the fume removal efficiency according to the formula in the standard text 3.6.