Changing the Receiver/Dryer

Now that the Kubota has been mounted on the brackets, it is time to start re-assembling it and integrating it with the rest of the systems, or "creating our Frankengen".  The heat exchanger and salt water boost pump (for the Kubota engine) were installed.  The water filter housings were mounted on the bulkhead also. 

Kubota heat exchanger and water filters for watermaker

We had decided to change the refrigerant from R12 to R134a.  Since the DC system already utilizes R134a, we only will have to carry one type of refrigerant.  (It's a dual circuit cold plate and can run two types of refrigerant if we so choose.)  While flushing the old system in preparation for the new refrigerant, Mike checked the existing water-cooled refrigeration condenser unit and found that it would not pass the refrigerant through the the receiver/dryer.  The receiver/dryer stores liquid refrigerant for the refrigeration system until it needs it.  It contains two felt filters and desiccant (drying pellets) between them.  It turns out that it was clogged.  You can see dirt in this picture.  Mental note to selves:  change the filter dryer every year, as recommended by the manufacturer, to prevent this from happening to us.

Old receiver/dryer cut open for inspection

Dirt in old receiver/dryer

So the new receiver/dryer arrived and Mike brazed it into the assembly.  This assembly will be in the raw water cooling circuit for the Kubota engine.  The tube on the right is a heat exchanger which contains two circuits of tubes -- one set for raw water and the other for the coolant.  At the top of the tee on the left he installed a charging port.  This will make it easier to charge (add refrigerant to) the refrigeration system.  By design, this type of system may lose refrigerant over time (just like the air conditioner in your car), necessitating a means to charge the system.