How to Choose a Water Tube Gas Fired Steam Boiler for Plant Integration

Start with the steam duty

Choose the SZS model by required evaporation capacity first. The Water tube gas fired steam boiler range runs from 10 to 50 t/h across the SZS10, SZS15, SZS20, SZS25, SZS30, SZS35, SZS40 and SZS50 models. This gives a plant several capacity points to match its process demand instead of selecting from a single output size.

The rated pressure is 1.25 MPa, with a 1.6 MPa option shown in the product range. Rated steam temperature is 194°C or 204°C. Send your required steam output, pressure and temperature together when asking us to size the boiler. A capacity choice made without the pressure and temperature requirement can leave the boiler and the process poorly matched.

Check fuel demand and thermal performance

The SZS boiler is designed for gas firing and is also listed with liquid-oil operation. Gas consumption across the models is 790.3 to 3898 Nm³/h. The corresponding diesel consumption figures are 679.3 to 3398 kg/h. These are useful for checking whether your fuel supply and plant utilities can support the selected output.

Design thermal efficiency ranges from 92.8% to 93.2% across the listed models. The combustion chamber uses a full-membrane water-cooled wall and narrow-pitch tube-membrane water wall. The wall structure improves airtightness and limits heat loss, while micro-positive pressure combustion supports the intended combustion arrangement.

Match the boiler to the installation space

The largest installation constraint may be transport and access, not the boiler room floor area alone. Shipping length ranges from 7,700 mm for the SZS10 to 12,820 mm for the SZS40 and SZS50. Shipping width ranges from 2,750 to 4,390 mm, and shipping height from 3,680 to 4,400 mm. Boiler weight ranges from 30.6 to 70 tonnes.

Measure the route from unloading point to boiler room, including turns, clear openings and lifting positions. For example, a plant considering the SZS30 should plan around its listed shipping dimensions of 10,850 mm length, 3,890 mm width and 4,200 mm height, plus its 52-tonne boiler weight. Confirm that the route and lifting plan can handle the selected model before finalizing the layout.

The main steam outlet ranges from DN150 to DN300. SZS10 and SZS15 use DN150 outlets; SZS20, SZS25 and SZS30 use DN200; SZS35 and SZS40 use DN250; and SZS50 uses DN300. Your steam header design should therefore be checked against the selected model's outlet size.

Consider inspection and heat-loss control

Inspection access is built into the arrangement. Fire viewing holes are provided at the front and rear of the upper and lower drums, and an inspection door is arranged at the rear for overhaul and cleaning. These access points suit plants that need regular visual checks and maintenance access around the boiler body.

The insulation uses aluminum silicate fiber followed by refractory cement. The furnace body temperature is controlled below 45°C, which helps limit heat loss from the boiler body. Leave sufficient working access around the inspection points and rear door when planning the room. Do not place the boiler against a wall if that blocks the rear maintenance route.

Which SZS model fits your working requirement?

Select SZS10 when your required evaporation capacity is 10 t/h and the listed DN150 outlet and 7,700 mm shipping length suit your plant. SZS15 is the next capacity step at 15 t/h, also with a DN150 outlet.

SZS20 through SZS30 suit requirements from 20 to 30 t/h and use a DN200 main steam outlet. SZS30 weighs 52 tonnes and has a shipping size of 10,850 mm by 3,890 mm by 4,200 mm, so it requires a carefully planned delivery and lifting route.

SZS35 and SZS40 cover 35 and 40 t/h with DN250 outlets. SZS50 is the 50 t/h option and uses a DN300 outlet. Its listed shipping dimensions are 12,820 mm by 4,390 mm by 4,400 mm, with a boiler weight of 70 tonnes. Choose this model only when the steam duty and the available transport and installation arrangements support that scale.

Questions to settle before ordering

Prepare the sizing request

The SZS range suits plants that need 10 to 50 t/h of steam and can accommodate its pressure, fuel, outlet, transport and maintenance requirements. Send us the required evaporation capacity, rated pressure, steam temperature, fuel type, steam header size, available room dimensions and delivery route so we can match the request to an SZS model.