the scale of catering industry 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. 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. The maximum allowable emission concentration of cooking fume per unit in catering industry and the minimum removal efficiency of cooking fume purification facilities shall be implemented according to the provisions in Table 2. Cooking and food industry units that discharge lampblack must install lampblack purification facilities and ensure that they run as required during operation. The unorganized emission of lampblack is regarded as exceeding the standard. 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. The outlet of the exhaust pipe should be oriented away from vulnerable buildings. The specific provisions on the height and position of the fume exhaust pipe shall be formulated by the provincial environmental protection department. ?