Tech Corner | September 2017
Procedure for Cleaning of Exchanger Plate Interior
Solex Thermal Science (Solex) heat exchangers, like other heat exchangers, can suffer from fouling caused by microorganisms, deposition of solids, or scaling from calcium found in the water passed through the heat exchange plates. Fouling can decrease thermal efficiency and increase pressure drop, both of which can negatively impact plant operations. Thankfully, Solex heat exchanger plates can be cleaned using a fast, environmentally procedure which returns the plates to an ‘as new’ condition.
One of the clearest signs of fouling in a Solex heat exchanger is an increase in pressure drop over time. This indicates that fluid passages in the heat exchanger are becoming restricted. If this phenomenon is noted, it is likely that the plates have become fouled or plugged and need to be cleaned using the following procedure.
- Prepare a 6% citric acid solution; this solution is an effective and environmentally friendly way to remove corrosion and contaminants from the interior of the plates. Nitric acid can be used as an alternative but is often more difficult to handle.
- Close the valves to the inlet and outlet manifolds of the Solex heat exchanger to isolate the unit from the plant piping system.
- Open the vent on the top heat exchanger manifold.
- Drain all process fluid (to a safe location) from the plates by opening the drain on the bottom heat exchanger manifold, once no fluid is left close the drain.
- Fill the plates completely with 6% citric acid solution by pouring through the vent on the top heat exchanger manifold.
- Let the solution stand in the heat exchanger for 2 hours.
- Drain the solution (to a safe location) from the plates by opening the drain on the bottom heat exchanger manifold.
- Flush the heat exchanger with clean water for 30 minutes or until no solids appear in the flushed water.
- Close the drain and the vent on the upper manifold.
- Reconnect the heat exchanger manifolds to plant piping.
By monitoring pressure drop across your Solex heat exchanger, you can identify instances of fouling and incorporate cleaning and flushing of the exchanger plates into your maintenance planning in order to avoid costly decreases in heat exchanger performance.
This entry was posted on September 28, 2017