Project Brief

This project covered the installation of an economiser on the flue stack of the lead boiler in a large brewery. The boiler typically runs for 50 weeks of the year.  It is shut down for 1-2 weeks a year for an annual overhaul/service/ It is a 9,000 kg/hr boiler and it can be run unmanned for up to 72 hours.

The Solution

• The economiser improves the efficiency of the boiler by pre heating the water from the hot well tank to a higher temperature by using the waste heat from the boiler in the flue stack.
• This will then enter the boiler at a temperature closer to the temperature of the water already in the boiler.
• This results in less heating in the boiler giving a cost saving and also quicker response time to a large steam draw on the boiler.

Project Benefits

• The total cost of this project was estimated to be €80,592.
• Taking an average of the efficiency over the whole operating range of the boiler this will give an annual saving of €23,096.
• There is also a potential annual carbon credit sale of €3660.
• Bringing the total savings up to €26,576, this gives a payback period of 3 years.
• The installation of the economiser is also expected to reduce CO2 emissions from the site by 122 tonnes per annum. This equated to a reduction in CO2 emissions of 0.13 kg CO2/HL.
• Thermal efficiency ratio will be reduced by 2.4 MJ/HL.