Steam is an efficient method of transferring energy and was the corner stone of the industrial revolution, producing motive power to railway engines, pumps and stationary engines (used in collieries and mills) and is still used today to feed turbines producing power, although these are now being gradually replaced by gas and oil fired units. Today, apart from heritage railways and traction engines, steam is more widely used to transfer heat to manufacturing processes such as food, dairies, chemicals, textiles, building blocks, plastics, breweries etc.
Steam systems are powered by highly efficient boilers and generators working at a general pressure of 10bar (150psi). It is good practise to transmit steam at high pressure which requires smaller bore pipework and reduce down at the point of use. Steam pressure and temperature is relative, therefore the higher the pressure, the higher the temperature. If the manufacturing process requires higher temperatures a higher pressure boiler will be required, although a super heater will produce a dry, high temperature steam without raising the boiler working pressure. Thermal oil systems run at high temperatures without the need for pressure. These units are becoming more popular.
The enemy of all steam systems is condensate (water). Should condensate build up in a steam system, the result can be catastrophic, especially on a cold start up. More commonly, if the condensate is left to build up, the process becomes waterlogged and inoperative. To counteract this, a steam trap is fitted on the outlet of the process. Essentially a steam trap opens to remove condensate and shuts when the condensate flow stops and steam starts to pass. There are many types of steam trap available for different applications.
It is essential that condensate returns are clean and not contaminated. Returning oil, detergents or any contaminates back into the boiler will have disastrous consequences on the boiler which could easily explode. Therefor it is critical that wherever there is a danger of this occurring (such as tank heating through a coil) the condensate is monitored frequently.
Once the condensate is discharged, it returns to the boiler hotwell, hot and pure. This results in less energy been required to raise this water back to steam once it is pumped back into the boiler. Some systems are ‘total loss’, which means that the steam is injected directly into the product with the only returns being line drains. Other processes result in high temperature condensate returns which can cause problems with the hotwell boiling and vibrating.
All steam boiler systems require ongoing investment to keep up with operating and safety legislation and to ensure that boilers operate safely and efficiently.
JBC is positioned at the forefront of boiler service and maintenance. Its reputation is down to the skills and expertise of its workforce and the reliability and flexibility that give our customers peace of mind all year round.