What is the structure and process principle of horizontal gas-fired three-pass boiler?
Industry boiler is an important thermal power device, which is widely used in factory power, building heating, people's life and other aspects, with a large demand and a wide variety. According to the different flue gas passes, gas-fired boilers are divided into two-pass and three-pass boiler structures. Here, ZOZEN Boiler focuses on the structure and process principle of the common three-pass boiler.
The first pass: after the fuel is atomized by the burner, the formed torch is filled in the full-waveform furnace liner and transmits radiant heat through the wall of the furnace liner;
The second pass: the high-temperature flue gas generated by combustion gathers in the combustion chamber and turns into the second return journey, that is, the tube bundle area of the threaded flue pipe. After convective heat exchange, the flue gas temperature gradually decreases and then reaches the front flue box, where it turns into the third return journey;
The third pass: To reduce the resistance, the third return trip is designed as a smooth tube bundle area. After heat exchange, the flue gas then enters the condensing economizer and chimney through the rear smoke box, and is finally discharged into the atmosphere.
WNS horizontal gas-fired boiler produced by ZOZEN has three passes, with a single capacity of 1-20t/h, which has the characteristics of safety, reliability, high efficiency, energy saving and environmental protection, convenient maintenance, automatic and intelligent control, etc. The thermal efficiency of the boiler is as high as 98% or more, and the low nitrogen emission of NOx below 30mg/Nm³ can be realized.
-
WNS series gas-fired (oil-fired) steam boilerLive Chat1-20 t/h0.7-2 MPa
-
WNS series gas-fired (oil-fired) hot water boilerLive Chat0.7-14 MW0.7-1.25 MPa
-
SZS series gas-fired (oil-fired) steam boilerLive Chat2-110 t/h1.25-5.3 MPa
-
Email us
-
WhatsApp: +86 18861589035
WeChat: +86 13506150756
Live Chat

-
Cambodian rice processor AMRU Rice generates a large amount of rice husk during production and requires a stable steam supply for cleaning, steaming, drying, and other processing stages. Based on the company’s fuel availability and steam demand, ZOZEN Boiler supplied an ASME-compliant DZL series single-drum biomass boiler. The boiler converts rice processing by-products into thermal energy and provides continuous steam for the production line. ZOZEN DZL Biomass Steam Boiler Supports Ric...06 Oct 2026 -
Recently, activities related to the China-ASEAN Expo have continued to attract attention. As an important economic and trade platform connecting China and ASEAN markets, the China-ASEAN Expo brings together enterprises, buyers, and industry organizations from different countries and regions. It provides manufacturing companies with opportunities to understand market demand, present product solutions, and conduct business exchanges. The 23rd China-ASEAN Expo Concludes Successfully During the ...29 Sep 2026 -
From September 29 to October 1, 2026, AHR Expo Mexico 2026 will take place at Expo Guadalajara in Guadalajara, Mexico. ZOZEN Boiler will present its industrial boiler products and solutions developed for overseas projects at Booth 1847. During the exhibition, the ZOZEN Boiler team will introduce its oil- and gas-fired boilers, biomass-fired boilers, thermal oil heaters and related products to customers across Latin America. The team will also discuss fuel adaptability, thermal system configurati...22 Sep 2026











