Novel structure, compact size, high thermal efficiency; dust and smoke emissions are significantly below standards. This series of boilers consists of five major components: drum, furnace tube, upper and lower tube plates, and threaded smoke tubes. The combustion chamber is located at the bottom of the boiler and employs side-spray combustion technology with threaded smoke tubes for heat transfer elements, achieving maximum complete combustion and energy conversion. This ensures the boiler's thermal efficiency and reduces the user's operating costs.