If you are a user looking for a steam solution, you may be confused about the choice between a steam generator and a steam boiler. This is a common trouble in boiler selection. They both generate energy through steam, but they achieve this in different ways. These differences affect all aspects of each system, including their size, operation, and most importantly, their applications. Therefore, you must understand the specific differences between them in order to choose the most suitable system for your energy production needs.

What is a steam boiler?

Steam boilers are usually larger pressure vessels that can provide energy for industrial manufacturing. They do this by using a complex fuel system to heat water to boiling point. One thing to note is that the high-pressure and high-steam output capacity of the steam boiler requires fully certified and licensed operators to operate on site. There are two common designs of steam boilers: fire tube and water tube. Usually, in the process of heating to generate heat, steam will be injected into the system and flow to the heated equipment through pipes.

Steam boilers are usually used to comfortably heat and maintain industrial process temperatures.

What is a steam generator?

Compared with steam boilers, steam generators use less steel in their design, using single tube coils instead of many smaller diameter boiler tubes. Steam generators usually have low water content. Water is pumped into one end of a continuously wound steel pipe (coil), and a mixture of steam and water is produced at the outlet. Due to the nature of its design and due to its very low water content, the steam generator cannot deliver steam when the burner is not burning. Since water can be sucked in through the coil and transferred to the process load, the steam generator is also not suitable for changing steam loads.

What are the differences between a steam boiler and a steam generator?

From the analysis of the principle of steam generation, the steam generator and the Steam boiler are in an intersecting relationship. Both steam boilers and steam generators belong to a kind of boiler products, but there are big differences between the two, mainly in:

1. Different water capacity

2. Different safety factors

3. Different procedures

4. The speed of steam generation is different

5. Different thermal efficiency

6. National supervisory inspection is different

7. Different equipment installation

1. Different water capacity

Steam boilers divide the tonnage of boiler products according to the rated evaporation capacity. For example, a rated evaporation capacity of 1 ton means that 1 ton of steam can be produced per hour, and the rated evaporation capacity ranges from several tons to dozens of tons.

The steam generator is a small boiler product, and its water capacity is less than 30 liters, which means that the water capacity of the steam generator cannot be higher than 30 liters.

2. Different safety factors

Steam boilers are pressure vessels and special equipment. When the pressure in a closed boiler exceeds a critical value, an explosion will occur. Once the steam boiler explodes, the energy released per 100 kg of water is equivalent to 1 kg of TNT explosive.

The steam generator has no hidden danger of explosion and is absolutely safe.

3. Different procedures

The steam boiler has the risk of explosion accidents, so its safe operation is particularly important. For the operation of the steam boiler, registration procedures and inspection and acceptance are required, and operations can only be carried out after being qualified. The steam generator is a small steam product, and it does not need to be filed for acceptance. It can enter the working state after simple installation and debugging.

4. The difference in steam generation speed

Due to the large water capacity and slow heating of the steam boiler, the steam generation time is longer, while the steam generator has a small water capacity, so the steam generation time is faster.

5. Different thermal efficiency

The thermal efficiency of coal-fired boilers is generally around 75% or even lower, and the overall thermal efficiency of gas-fired boilers is around 90%. The thermal efficiency of a biomass-fired boiler is about 80%. Combining different types of boilers, the thermal efficiency of the boiler is about 85%;

The thermal efficiency of the steam generator can reach more than 90%, the warped fin heat ex-changer, the heat absorption speed is fast, the fuel utilization rate is high, and it is more energy-saving.

6. The national supervisory inspection is different.

The structural principle of the boiler must have potential explosion hazards. The state stipulates that the water capacity is less than 30L, which is not a special equipment, and the state is exempt from supervisory inspection. Most boilers whose water capacity far exceeds this data are special equipment that is strictly supervised and inspected by the state, and the steam generator has eliminated potential safety hazards in terms of structure and principle, and the state is exempt from supervision and inspection.

7.The installation location of the equipment is different

Large boilers require a boiler room and must be undertaken by a professional design unit with design qualifications. The design of oil and gas boiler rooms should be approved by the relevant competent authority.

Steam generators generally do not need a boiler room. In addition to considering the fire protection and gas access of the location. 

Steam generator should be placed according to the following principles:

1. Place the terminal equipment nearby: directly place the steam equipment next to the terminal equipment, which can reduce the laying of pipelines and reduce heat loss and improve steam quality;

2. Place on the roof: Place the steam equipment on the roof for easy maintenance;

3. Place in the basement: Supervision-free steam equipment can be placed in the basement;

4. Place on the green belt: Supervision-free Steam inspection equipment can be placed on the green belt, not counting the building area.

Conclusion

When deciding which steam system is better for your business, the key considerations are simple: output and demand. Although the steam generator starts faster, it cannot meet most of the production needs due to its limited capacity. The steam boiler is designed for long-term industrial use and can provide large-scale, high-demand critical operations with larger capacity enough to support fluctuations in steam demand.

The most important thing is that steam boilers can better adapt to the needs of enterprises. According to your building structure or its energy usage, the steam boiler can be packaged and designed to meet any of your needs. If your company needs customized industrial boiler solutions, please contact EPCBboiler!

EPCB,your private boiler system expert!

Further Reading：

How to choose a boiler with high temperature heating? 

Boiler Burner Selection Guide | How to Choose a Suitable Burner?

Steam Boiler System Selection (Part 1)

Steam Boiler System Selection (Part2)

Differences Between Thermal Oil Boilers and Steam Boilers