1, cut off the power supply, and first focus on cleaning the smoke exhaust passage parallel to the range hood through the smoke exhaust port. The kitchen smoke exhaust system in commercial places is relatively large. Unlike domestic range hoods, every part can be disassembled. For example, the cleaning of the smoke exhaust hood requires technicians to enter the flue and remove the thick oil with tools first. Because of the accumulation of a large amount of grease, it is necessary to use professional oil agents. Spray oil with high-pressure cleaning machine for half an hour, and then rinse with clean water. ? Some smoke exhaust pipes are narrow, and technicians cannot enter the pipes to work. In order to avoid the hidden danger caused by the oil fume in the pipeline, many companies usually use mechanical equipment to open the pipeline and clean it. This method is simple and clean, and some pipelines are complicated, so manual cleaning may leave dead ends. ? When choosing equipment to clean the opening, we should pay attention to the sealing treatment at the opening, otherwise it will leak oil and leave a safety hazard, which is more important when designing the hotel kitchen. ? 2. Clean the fan. After a long period of operation, the fan blades will become thicker because of the accumulation of oil pollution, and the internal space of the fan will also become smaller because of oil pollution, and the exhaust effect will become worse and worse. To clean the fan, first remove the fan and clean the internal impeller and inner wall; Then clean the fan surface. Before assembly, lubricate the transmission device in the fan to ensure the flexible exhaust of the fan. This step is critical and is operated by experienced technicians. ? 3. Clean the fume purifier. The ventilation effect of kitchen smoke exhaust system is also affected by oil fume purifier. After the purifier is used for a long time, there will be a lot of oil stains on the internal electrode plate and filter screen, and the purification effect of lampblack will become worse. According to statistics, about 80% of kitchens have poor smoke exhaust because of long-term neglect of cleaning the built-in filter screen of oil fume purifier. There are many kinds of oil fume purifiers, which are soaked with cleaning agent first, and then cleaned according to different kinds of purifiers combined with cleaning machine.