In this article the industrial steam boiler specialists at Water Treatment Services look at how standards of boiler water treatment can affect safety, performance and costs.
The article highlights the need for good boiler management practices and why a water treatment programme is essential. It also looks at the impact of boiler corrosion, thermal fatigue and the build-up of scale on heat transfer surfaces.
Boiler water treatment
The heating industry might talk about “catastrophic boiler failure”, but what that means in practical terms for most businesses that rely on steam boilers to heat or power their operations is complete disaster.
A good way of understanding just how much damage can be caused by an exploding fire-tube boiler is to browse through some YouTube videos. One video we’ve seen shows a 10-metre-wide hole appearing in the wall of a plant room, with the boiler itself landing 30 metres from its original location. The common factor to all of these catastrophic events is the root cause – a poorly maintained and operated boiler.
Businesses in the UK use a range of boilers, of differing capacities and construction types. Catastrophic failures and explosions are very rare, but only because industry takes steps to prevent this from happening. Maintaining your steam boiler properly can also substantially reduce your energy and operating costs.
Fire-tube or shell boilers
In the UK, fire-tube boilers are often known as shell boilers. They are a popular choice, which is often down to their lower installation costs than other styles of boilers. Fire-tube boilers are often thought of as a reliable piece of kit in a plant room, which you can just leave running and forget about. This is a dangerous way of thinking however, and regular boiler water treatment and maintenance programmes are very important. Looking after your boiler and managing it properly should mean it delivers many years of regular service.
Boiler management issues
Industrial steam boilers are generally built to last, by engineering companies who know what they are doing. Over the years’ industry has been using these boilers, their manufacture has been refined considerably. Boilers only very rarely leave the factory with defects. Any failure in the boiler will usually be down to the way it has been used, how the water has been treated, or simply a lack of maintenance.
Water treatment for steam boilers
Any water treatment company which is contacted by a client asking for help to make their boiler run more efficiently will start by analysing the feed-water. Changing the boiler feed-water, or implementing a low-cost water treatment programme can pay for itself quickly. Boilers will run more efficiently, produce more steam, and cost less to run.
Combustion Engineering Association (CEA)
The main industry body in the UK’s boiler sector is the Combustion Engineering Association or CEA, and they have produced an excellent guide on boiler water treatment. Unlike many other publications, the one from the CEA is aimed at anyone responsible for managing water treatment for steam boiler systems, and doesn’t assume any prior chemistry or water treatment knowledge. It’s essential guidance, whether you’re managing water treatment in-house, or contracting out the work to a specialist third party water treatment company.
Some of the key information in the guide looks at best practice for keeping your boiler running reliably. The guide recommends that feed-water for any steam boiler should be pre-treated, to make sure it comes up to the standards stipulated by the boiler manufacturer. The guidance also recommends that the water be monitored and controlled on a continuous basis, to make sure the boiler is protected at all times. The CEA guide can be downloaded here.
Boiler corrosion and thermal fatigue
Research has shown that around 80% of fire-tube boilers that fail do so because of fatigue. This is most often caused by thermal fatigue or corrosion. It’s easy to guard against both of these risks by making sure that the boiler feed-water, make-up water and condensate return are treated effectively.
Problems caused by scale in boilers
The most common cause of boiler overheating is the build-up of scale which is caused by the precipitation of salts found in hard water. The scale precipitates-out and builds-up on the surfaces of tubes, and other heat transfer surfaces. It can be addressed by effectively treating the boiler water to control the effects of these minerals (calcium and magnesium) using specially formulated scale inhibitors or pre-treatments. In the worst-case scenario, scale build-up could cause boiler failure or thermal fatigue, with the only option being to replace the boiler completely.
Scale comes in different types, but all can affect the efficient running of your boiler. Scale which is as little as 3mm thick can lead to a drop in heat transfer efficiency of as much as 20 to 25%. If there are high levels of silica and iron in your feed-water, then the problems can be much greater and lead to a much larger drop in transfer efficiency.
Can better boiler water treatment reduce costs?
Most companies operating an older boiler have already put in place a boiler water treatment programme. But are these running as effectively as they could be? Have you considered alternatives such as reverse osmosis or water softeners? If not, it could make commercial sense to engage a water treatment company such as Water Treatment Services to conduct a boiler audit and recommend ways to improve efficiencies and reliability, and to save money.
Industrial steam boiler specialists
Water Treatment Services offer a comprehensive range of water treatment solutions for the management of industrial boilers and steam generating systems.
Our experts can help you optimise costs and operational efficiencies, reduce downtime, achieve water and energy savings, and increase plant reliability and safety.
With offices in London serving the South and South East England, Manchester (North West), Birmingham (Midlands), Bristol (South East England and Wales), Leeds (North and North East) and Glasgow (Scotland), supported by regional teams of specially trained technicians and consultants we can offer professional, cost effective boiler water treatment and engineering services throughout the UK and Internationally.
Contact us today to learn how our industrial steam boiler solutions can help you and the environment.