1. Reduce blowdown

        As water evaporates in the boiler, salts and minerals accumulate that can cause corrosion and scale. To reduce the build up of these dissolved solids, a portion of the water (usually around 4-10 per cent) is bled off (released) periodically.

        To reduce excessive bleed, a conductivity probe can be used to measure the salt level within the water and only blowdown when that level exceeds a set value. The payback period is usually around one to three years and can reduce boiler energy, required to heat up feed water, by 2-5 per cent, plus saves on water and water treatment costs.

2. Recycle or reuse blowdown

        It may be possible to reuse the boiler blowdown water for other activities such as cleaning, provided it is of appropriate quality and any chemicals used are compatible.

3. Blowdown heat recovery and flash steam recovery

        A blowdown heat recovery system consists of a heat exchanger and flash tank.

        The flash tank drops the pressure of the blowdown, converting some of the blowdown into low-pressure steam which is sent to the deaerator and can be used again in the boiler. The remaining water is sent to a heat exchanger and used to preheat the incoming feed water. The system also may assist businesses to comply with local authority requirements limiting the discharge of hot liquids to sewer.

4. Reduce makeup usage

        Alternative water sources such as rainwater, condensate, recycled water, process water and bore water can be substituted for mains water where appropriate.