How to save water in engineering

Northern Ireland has a highly sophisticated and productive engineering sector. Engineering processes can use significant volumes of water, which can be a drain on costs and also impact the environment. Water sustainability is becoming a higher priority consideration for the engineering sector due to increasing pressure on water resources.

There are several water-saving measures that engineering businesses can use to improve efficiency.

Condensate recovery

Condensate recovery is a useful technique to reduce water consumption in boilerhouse operations that can also lead to significant energy savings. Where possible, condensate should be collected and returned to the boiler hotwell to reduce the demand on water and energy use required to produce further steam and hot water.

Cooling systems

Equipment that requires cooling water is often simply connected to the nearest available water supply resulting in mains water being used for cooling purposes and often on a ‘once-through’ basis. Fitting a closed (full or partial) loop system may allow this water to be re-used after cooling. A filter or small purge flow to drain may be required to control the build-up of contaminants which may negatively affect the system, eg scale build-up.

Automatic shut-off

Equipment that does not require a constant supply of water can be isolated using a simple control system to minimise water wastage. Switching methods can include:

• limit switches
• signals from existing process controls
• signals from existing interlocks

Efficient rinsing

The water used in the rinsing of products or parts can often be minimised by using techniques such as trigger-operated spray guns or ‘countercurrent rinsing’. Trigger-operated spray guns stop the flow of water when the trigger mechanism is released minimising water wastage. In countercurrent rinsing, the product or part is rinsed in tanks first in reused water and then in progressively cleaner water. At the same time, the rinse water moves progressively from the last rinse towards the first rinse.

Recycling technology

Water used in industrial processes can often be reused after suitable treatment to remove unacceptable impurities. These treatment technologies include:

• filtration
• clarification or sedimentation
• centrifugation
• flotation
• ion exchange
• distillation/stripping
• absorption/adsorption

Invest Northern Ireland water efficiency support and advice

For more detail on water efficiency measures and benefits, you can download Invest NI's practical water efficiency guide for businesses in Northern Ireland (PDF, 956K).

Your engineering business may be eligible to get a sustainability report, which can help you to measure, monitor and report on your environmental impacts, demonstrating transparency and accountability - find out more about Invest NI’s Sustainability Reports.

Invest NI provides expert advice to help develop business-specific energy and resource efficiency strategies. Tailored advice, support and funding can help your business operate more efficiently, minimise waste, reduce costs and improve your impact on the environment - find out more about support to save energy and reduce resource consumption.