Improving Condensate Recovery Efficiency
It is not uncommon for process plants to have poor condensate return efficiencies. These efficiencies many times don’t tend to affect day-to-day operations so are often overlooked, even though they are a real bottom-line cost and sometimes can be an easy fix.
A modern Kadant Johnson designed steam and condensate system can return 90% or higher of the process condensate, anything significantly below this is classed as poor condensate recovery (i.e. 70 to 80%).
It is recommended to recover lost condensate, as it contains valuable heat energy and boiler house water treatment chemicals.
The causes of poor condensate return efficiency are:
- Poorly designed system. If the system has been designed incorrectly for the process application, this will lead to inefficiencies in steam usage and/or condensate recovery. This is usually apparent from day one of commissioning.
- System out of balance. In this instance, the system was efficient once but now due to either poor maintenance, poor operation, or change of application load (expansion/reduction in the process) from original design it is now “out of balance” and not operating efficiently.
One can see from the above that an efficient steam and condensate system is analogous to a tailor-made suit if it was badly made initially or you’re coming back to it 20 years later, it’s not going to fit or look good.
Now the good news is that your steam usage and condensate return efficiency can be fixed, in some cases it may be a simple logic/operational (setpoint) change to a partial system rebuild. The sooner the inefficiencies are addressed the sooner the return on your improved process efficiency starts.
- Recovery of valuable heat energy from within the condensate, thereby improving overall energy efficiency.
- Recovery of boiler house water treatment chemicals.
- Hot condensate being lost also has an environmental impact, if this is discharged to a nearby river. In most countries’ hot condensate discharge of this type carries serious penalties and is not good for wildlife in the river.