Greener Upgrades blog series #7
Making an informed decision on steam
When selecting a steam boiler, understanding the different types of boilers is critical in terms of system performance, size and logistical requirements. Below highlights key aspects of both technologies.
Space and weight
Fire tube boiler: Typically, heavy and requires a lot of ancillary equipment.
Aggreko steam boiler: Compact and includes integrated components such as the boiler, blowdown, water softener, and chemical treatment systems, all housed in a 10ft or 20ft high cube container. This containerised steam boiler house has a condensed footprint, ideal for projects where space is at a premium. It is lightweight, simplifying logistics and transport, with no crane required for lifting.
Steam quality
Fire tube boiler: during sudden steam demand, moisture residue from the water surface can increase, potentially compromising steam quality.
Aggreko steam boiler: delivers very high steam quality, with 99.5% dry saturated steam, ensuring better performance and efficiency. This also minimises the amount of water and impurities entering the steam line, resulting in higher energy content.
Startup time
Fire tube boiler: requires approximately 60 minutes to start up due to the large mass of water and steel.
Aggreko steam boiler: achieves startup within three minutes from cold, significantly reducing downtime. Our boiler also has the ability to run without manual intervention for startup under most circumstances.
Burner operation
Fire tube boiler: When no steam is demanded, the burner continually switches on and off, wasting energy and increasing maintenance needs. It also requires manual intervention to startup. Aggreko steam boiler: Can stand down when no steam is demanded and restart automatically without manual intervention, improving energy efficiency and reducing maintenance. The dual fuel burner, capable of operating on gas, diesel, or HVO, helps minimise the carbon footprint. Our boilers can achieve 20 – 25 % savings on fuel in start/stop applications.
Running costs
Fire tube boiler: Inefficiencies can lead to higher running costs.
Aggreko steam boiler: High efficiency minimises running costs. High combustion efficiency ensures maximal conversion of fuel into useful heat, while the high boiler house efficiency maximises the useful energy from fuel.
Response to demand
Fire tube boiler: has lag characteristics that limit operational flexibility.
Aggreko steam boiler: can rapidly increase steam flow without loss of temperature and pressure, providing greater flexibility and responsiveness. It adapts quickly to changes in demand, optimising steam output to match varying load requirements.
Safety
Fire tube boiler: the large volume of water stored can pose a significant safety risk.
Aggreko steam boiler: designed to eliminate the need for large water volumes, enhancing overall safety. The low water volume design, which is ten times less than fire tube boilers, ensures high levels of safety.
Scale control
Fire tube boiler: scale formation due to low water velocity can affect heat transfer and safety devices.
Aggreko steam boiler: scale is easily detected without internal inspection, allowing for early corrective action and better maintenance.
Water levels
Fire tube boiler: Water level loss is a common cause of equipment failure.
Aggreko steam boiler: Does not have a distinct water level, so level controls are not required, reducing complexity and potential failure points.
Maintenance requirements
Fire tube boiler: high maintenance is required due to the risk of corrosion.
Aggreko steam boiler: require slower maintenance, thanks to its advanced design and quality components,increasing uptime. Efficient maintenance is further enhanced by the ARM fitted as standard, which enables proactive diagnostics and close monitoring forenergy use.
Blowdown
Fire tube boiler: requires regular blowdown due to low tolerance to dissolved solids.
Aggreko steam boiler: has a high tolerance to dissolved solids and requires very low blowdown, saving on water and treatment costs.
Installation and commissioning
Fire tube boiler: often requires extensive pipework and ancillary components, complicating installation.
Aggreko steam boiler: minimal interconnecting pipework simplifies and speeds up installation and commissioning. The solution can also be scaled up in capacity by running sets in parallel to suit larger demands.
Environmental compliance
Aggreko steam boiler: featureslow NOx emissions for compliance with environmental standards, guaranteeing amore sustainable operation.
Flexibility
Aggreko steam boiler: capable of operating on standard water (hardness below 20˚D), making it suitable for diverse applications.
Conclusion
Aggreko steam boilers offer significant advantages over traditional fire tube boilers, including faster startup, high steam quality, responsiveness, enhanced safety, lower maintenance, and reduced running costs. The compact, containerised design simplifies installation and logistics, making it an ideal choice for projects with limited space. Additionally, the high efficiency, environmental compliance, and scalability of Aggreko boilers make them an idea for many applications, particularly where operational flexibility and efficiency are critical.