Introducing ZOZEN’s 3 Pass Steam Boiler – Efficient and Reliable

May 23, 2024

Industrial steam boilers play a crucial role in various industries such as chemical, food processing, textile, paper, pharmaceuticals, and energy. They provide heat and power, driving production equipment and heating processes to meet the steam demand in industrial production. ZOZEN introduces its 3 pass steam boiler, which offers unparalleled efficiency, energy savings, environmental friendliness, easy maintenance, and advanced automatic intelligent control.

The Three Pass Process:
Gas-fired steam boilers are classified into two categories based on the flue gas return, namely, two-pass and three-pass boiler configurations. It is important to note that whether it is a two-pass or three-pass boiler structure depends primarily on the boiler’s performance, as long as it meets the efficiency, exhaust, and other requirements for enterprises. ZOZEN’s 3 pass steam boiler, part of the WNS series, is designed to provide the following process:

  1. First Pass: The fuel is atomized by the burner, creating a flame that fills the entire corrugated furnace, transferring radiant heat through the furnace walls.
  2. Second Pass: The high-temperature flue gas generated by combustion converges in the rear combustion chamber, turning into the second pass, which is the threaded smoke tube bundle area. After convective heat transfer, the flue gas temperature gradually decreases until it reaches the front smoke box, where it turns and enters the third pass.
  3. Third Pass: To reduce resistance, the third pass is designed as a light pipe bundle area. After heat exchange, the flue gas then enters the condensing economizer and chimney via the rear smoke box, finally being discharged into the atmosphere.

ZOZEN’s 3 Pass Steam Boiler Product:
ZOZEN’s WNS series oil and gas-fired steam boilers are horizontal, shell-type, wet-back 3 pass steam boilers with capacities ranging from 1 to 20 t/h and operating pressures from 0.7 to 2 MPa. They are suitable for a wide range of fuels, including natural gas, coke oven gas, biogas, as well as diesel, heavy oil, light oil, and residual oil.

This 3 pass steam boiler has a Large furnace volume, ample steam storage space, and heating surfaces for efficient, high-quality steam generation.
The hinge structure of the smoke box ensures good sealing, facilitating inspection, cleaning, and maintenance.
This 3 pass steam boiler has a corrugated furnace which will be enhancing gas disturbance, improving heat transfer efficiency, increasing furnace strength and elasticity, and reducing boiler thermal expansion stress.
The threaded smoke tubes prolong the residence time of flue gas, intensifying heat transfer, improving thermal efficiency, with a heat transfer effect 1.4 times that of ordinary smoke tubes.
The economizer and condenser utilize waste heat from the flue gas, raising the feedwater temperature and lowering the exhaust temperature, achieving boiler thermal efficiency up to 98%. The economizer adopts finned tubes to increase heat transfer surface area and enhance heat transfer efficiency.

3 pass steam boiler
WNS 3 pass steam boiler

Customer Case Study:
ZOZEN provided a WNS series 8-ton light diesel 3 pass steam boiler to a comprehensive engineering company in Malaysia, marking another successful case in our overseas market. Equipment cost: It should be noted that the equipment cost of the boiler is not listed explicitly, as different models and specifications have different costs. Generally, high-pressure, large-capacity, and high-efficiency industrial steam boilers have higher costs.
In the production process at the palm oil plant, steam boilers play a critical role. ZOZEN’s WNS series 8-ton light diesel 3 pass steam boiler, with its efficiency, energy-saving, and environmentally friendly features, perfectly met the customer’s requirements. The boiler, with its advanced combustion technology and three-pass structure design, efficiently utilizes fuel, improves thermal efficiency, and reduces operational costs. The customer feedback highlighted the stability and efficiency of ZOZEN’s boiler, greatly enhancing their production efficiency and reducing operational costs. Notably, ZOZEN’s professional after-sales service team provided significant assistance during installation and commissioning, ensuring the boiler’s quick deployment.

ZOZEN’s Corporate Strength:
After years of rapid development, ZOZEN has actively promoted an operational model focused on innovative technology, quality management, and standardized services. We have established a computing center and local area network, implementing comprehensive computer information management in the industry. ZOZEN has provided quality services to customers in multiple countries and regions and established service centers in the United States, Finland, Indonesia, the Philippines, Thailand, Vietnam, and Uzbekistan, offering comprehensive services such as project technical consultation, solution development, and installation guidance. We have been honored with accolades such as AAA-level credit-rated enterprise and annual sales exceeding billions.

ZOZEN’s 3 pass steam boiler is an efficient and reliable industrial boiler. With its three-pass design, it offers high efficiency, energy savings, easy maintenance, and advanced automatic intelligent control. With a focus on innovative technology, quality management, and standardized services, ZOZEN has established a strong reputation and a global presence in the industry.


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