WNS Series Fire Tube Hot Water Boiler

WNS Series Fire Tube Hot Water Boiler

The WNS shell type fuel gas hot water boiler host is composed of a pot shell, front and rear tube plates, corrugated furnace liner, back combustion chamber, two-pass smoke pipe etc.

  • Rated thermal power : 0.7-17.5MW
  • Rated thermal efficiency : ≥96%
  • Rated pressure: ≤1.25MPa
  • introduction
  • Technical parameters
  • Goods Delivery
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The main body of the WNS type shell-type hot water boiler consists of a shell, front and rear tube sheets, a corrugated furnace, a reversal combustion chamber, a second pass smoke tube, a third pass smoke tube, manholes, hand holes, a return water device, a water outlet pipe holder, a steam-water separator, front and rear smoke boxes, explosion-proof doors, steel skid, and other components. The boiler is also equipped with auxiliary equipment such as a burner, automatic control system, circulating water pump, feed water pump, water treatment, economizer, condenser, valves and instruments.

When turn on the boiler, the automatic control system will automatically operate the boiler according to the set program, including startup, ignition, combustion, heating, load regulation, safety protection, etc.
The water circulation of the boiler is natural circulation. The smoke flow of the boiler is as follows: the fuel ignites from the burner, then the furnace burns, and the wet back returns to the combustion chamber. Next, the smoke flows through the second pass smoke tube bundle, front smoke box, third pass smoke tube bundle, rear smoke box, economizer, condenser, smoke duct, chimney, and finally enters the atmosphere.


  • Classic shell-type full wet back and downstream three-pass structure. The flame burns at a slight positive pressure in the large combustion chamber, fully extends, and has a low combustion heat load, resulting in low NOx emissions.

  • The front and rear smoke box doors and panels use a double-layer seal structure and are tested for air tightness to ensure good insulation performance. The double-layer seal opening and closing are synchronous, and maintenance and installation are convenient. The rear smoke box has a detachable explosion-proof door, which ensures safety and can also be used as a furnace inspection hole.

  • The internal device and various pipe openings are arranged reasonably, optimizing the internal water circulation, effectively preventing the generation of scale, and improving the heat exchange effect on the water side. Manholes and inspection holes are set up in weak areas with poor circulation to facilitate regular inspection and maintenance.

  • The boiler has a large water volume design, and the furnace body is not sensitive to load fluctuations. It is still suitable for users with large load changes.

  • The furnace adopts a corrugated furnace structure, which increases both radiation and convective heat transfer area, and meets the needs of the furnace body to freely expand after being exposed to high-temperature radiation.

  • Most of the main welds are welded by automated welding equipment to ensure product quality.

  • Low-resistance and high-efficiency threaded smoke tubes replace traditional flat tubes to enhance heat transfer and improve thermal efficiency.

  • The front and rear smoke boxes are equipped with condensate discharge devices to reduce corrosion of the heating surface caused by condensate water.

  • The boiler uses a new type of thermal insulation material, which has good insulation performance, light weight, and low heat dissipation.

  • The PLC fully automatic intelligent control system uses integrated control equipment and programmable logic controllers (PLC) to control the boiler. The advanced PLC serves as the "central processor" of the control system. The control system operates through a touch screen, greatly improving the automation level and reliability of the boiler operation, and making the operation more convenient and intuitive.

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Technical parameters of WNS series fire tube hot water boiler(gas/oil)

Model Rated thermal power Pressure Return water temperature Rated water temperature Heat transfer area Flue gas temperature Fuel Flue gas temperature Weight Water volume
natural gas city gas
MW MPa NG/CNG/LNG/LPG/LFO/HFO... mbar mbar t
WNS 0.7 0.7 0.7/1.0 70 95/115 26 ≤90(plus economizer) 50-100 70-200 4.6 3.2
WNS 1.05 1.05 40 50-100 70-200 6.12 4.6
WNS 1.4 1.4 53 50-100 70-200 6.9 5.6
WNS 2.1 2.1 79 50-100 70-200 9.9 6.8
WNS 2.8 2.8 103 100-200 100-200 10.7 9.0
WNS 3.5 3.5 1.0/1.25/1.6 70/90 115/130/150 122 100-200 100-200 11.8 10.3
WNS 4.2 4.2 153 100- 200 100-200 13.7 11.4
WNS 5.6 5.6 201 100-300 100-300 19.1 18.4
WNS 7 7 251 100-300 100-300 20.7 20.4
WNS 10.5 10.5 356 150-300 150-300 35.6 30.2
WNS 14 14 509 150-300 150-300 45.5 34.1

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Integrating R&D, production, distribution, and service-providing into one enterprise, EVERED attaches great importance to communication with customers. We have established an after sales visit team consisting of more than 56 persons. On the one hand, they timely solve the problems that our customers encounter; on the other hand, they collect feedback and improvement recommendations from our customers, to correctly orient our development and research.

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