Let’s keep on talking about TREG thermoregulation units. In a previous video we spoke about the different kind of fluids that are employed with TREGs. So now let’s talk about the kind of thermoregulation unit based on the kind of fluid employed. Starting with thermoregulating units that employ water. Typically it’s possible to use thermoregulating units with an atmospheric circuit or with a pressurized circuit.

The first main difference is represented by the working temperature range. Up to 90° C it’s clearly possible to use an atmospheric thermoregulation unit. Beyond 90° C, due to the boiling point, it’s necessary to use thermoregulating units with pressurized water, which means thermoregulating units with a closed and sealed circuit in order to ensure pressure resistance. As if it was a sort of pressure cooker, clearly with a series of additional safety measures, but it can be a topic for another video.

Often, pressurized water thermoregulating units are also employed because they offer an advantage, enabling to be installed at any point of the plant without respecting the heights. Let explain: an atmospheric unit, having an open hydraulic circuit, requires to have the expansion tank at the top point of the plant, otherwise, due to the principle of communicating vessels, the system would empty.

A pressurized thermoregulating unit is basically a closed and sealed circuit, then the water is put into circulation and once the air is vented from the high points of the system the unit can work without problems.

Clearly, the most appropriated thermoregulating unit can be selected based on the kind of plant. Many times, the atmospheric unit offers advantaged compared to a pressurized one. The pressurized unit, as said, offers the advantage that, once the air is vented from the circuit, the circuit is full, water is circulating and there are no further problems. But there are some industrial processes involving very complex circuits presenting various points where air pockets can form that are difficult to vent and eliminate.

In this case, an atmospheric thermoregulating unit installed at the higher point of the plant could be a winning solution, because the pump remains under the tank head, and so always fed by water, and push the water inside the plant. Possible air bubbles won’t arrive to the pump but will be directly gathered to the expansion tank or inside the water collection tank, which is installed at the higher point of the plant, and thus being automatically vented, without problems. This allows the pump to operate with no issues, especially in the start-up phase of the plant.