SZL type double drum vertical type chain grate boiler, high efficiency boiler output is big, heating up fast, the upper part is the main body heating surface, the lower part is the combustion equipment, the two body structure. Easy to transport, the boiler water cycle using natural circulation or forced circulation way. To ensure the safety and safety of boiler operation, the unique design of the front and rear arch to enhance the quality of coal, and strengthen the coal combustion. The series boiler technology, performance, environmental protection indicators have reached the national advanced level, the leading product for the boiler industry.