Steam Trap Back Pressure

What equipment I can use to return the condensate to the tank if a choose locate the Heat Exchanger at ground level, because it seems obvious I can't use a steam trap in this conditions.

No, even with 3 bar this should do it.

We use this configuration or similar from Spence and Armstrong. Where we use steam to force the condensate back. No Pumps.

Very economical, they have several PDF schematics as an example. You should find a schematic to best suit you. But contact your local Spence or Armstrong supplier for help.

If you can't install the exchanger above the condensate tank, you'll have to install a pump. A steam powered pump like phoenix911 mentions is an option if steam pressure above 3 bara is available. Otherwise, you'll need a mechanical pump.

1. You need to eliminate all condensate back pressure downsteam of the trap, i.e. run to a vented collection tank and pump it back to the boiler house.

2. Trap needs to be below the outlet of the heat exchanger.

These points will eliminate heat exchanger "STALL"

Use a steam-driven pump to lift the condensate from its lowest point. These are commonly known as "Ogden pumps" (usual disclaimer). It may even be possible to eliminate the condensate collection tank altogether.