The DZH (L) coal-fired steam boiler is a single drum vertical water fire tube shell boiler, with a combustion method of movable grate and chain grate. It is a horizontal three return water fire tube hybrid boiler, with a bundle of threaded smoke tubes arranged inside the drum. The water-cooled walls on both sides of the furnace are radiation heating surfaces, while the two wings of the furnace are convection heating surfaces The boiler body adopts a symmetrical arrangement of upper drum, water-cooled wall tubes, and headers in the overall structure. The boiler is composed of a cylinder and front and rear tube plates welded together. The boiler is equipped with fire-resistant walls, which have high combustion efficiency.
A lightweight chain grate is used for mechanical coal addition, equipped with a blower and induced draft fan for mechanical ventilation, and a scraper type slag removal machine for automatic slag removal. The front and rear arches of the furnace adopt a new energy-saving technology furnace arch. The fuel falls from the coal hopper onto the grate and enters the furnace for combustion. The flame refracts upwards through the rear arch, passes through the combustion chambers on both sides of the main body, and then turns back to the front smoke box. It then returns to the boiler tube bundle through the front smoke box and enters the economizer through the rear smoke box. It is then drawn by the induced draft fan through the flue and discharged into the atmosphere through the chimney.
This series of products adopts the latest technological achievements, such as arch shaped tube plates, threaded smoke pipes, etc., to solve the problems of tube plate cracks, water-cooled wall bursting, low thermal efficiency, insufficient output, and poor coal quality adaptability in shell boilers.

1. The boiler drum is composed of arched tube plates and threaded smoke pipes, which changes the structure of the drum from a quasi steel body to a quasi elastic body. The smoke pipes are changed from two return to a single return, solving the problem of tube plate cracks.
2. The use of threaded smoke pipes has enhanced heat transfer and improved the thermal efficiency of the boiler.
3. Stable operation, easy adjustment, sufficient output, fast boost, environmental protection and energy saving, high thermal efficiency, etc.
4. The boiler itself has a dust removal function, which enables the smoke and dust emissions of the boiler to meet the national environmental protection standards.
5. This series of boilers adopts arch shaped tube plates, two wing flues, threaded smoke pipes, etc., which solves the problems of tube plate cracks, bulging at the lower part of the drum, water-cooled wall tube bursting, low thermal efficiency, insufficient output, and poor coal quality in shell boilers.

DZL series coal-fired chain steam boiler