亚洲中文日韩-亚洲中文日韩大片在线观看-亚洲中文日韩国产一区-亚洲中文三级情片在线观看-亚洲中文色欧另类欧美动图-亚洲中文少妇影视

八、 According to the furnace flue gas pressure

1. Negative pressure boiler: the furnace pressure maintains negative pressure, there is a delivery and induced draft fan, which is the main type of coal-fired boiler; 2. Micro-positive pressure boiler: the furnace pressure is 2-5KPa, no need for induced draft fan, easy to low-oxygen combustion.