The initial start-up of a thermoregulating unit is a very delicate monent, on which many customers ask for our support.
Industrial thermoregulation units by Tempco are supplied completely tested and checked. Once on-site, the units must be filled with the working fluid and started-up, and this operation is crucial for the safe and optimal functioning of the units.
The filling is indeed a very delicate step. In case of water or pressurized water as working fluids, the operation is simplified because water easily flows within the hydraulic circuits, giving no problems related to air bubbles. The operation becomes more delicate with diathermic oil thermoregulating units: the heat transfer oil has indeed a high viscosity, capturing and holding air bubbles.
It seems a trivial tip, but the very first thing to do proceeding in the first start-up of a thermoregulating unit is to check the rotation direction of the pump. This is important for two main reasons, the first being to ensure the correct functioning of the unit to achieve maximum efficiency, and then because a wrong pump rotation direction can damage the spring of mechanical seals of the pump.
Let’s then start filling up very slowly the unit, taking care of completely eliminate the air within the hydraulic circuit. Once the air is completely removed, is it possible to proceed with the first start-up of the thermoregulating unit, turning on the pump and checking the pressure indicator on pump delivery. The pressure indicator must be stable, indicating the nominal project value of the working pressure of the pump. Otherwise, if the indicator is shaking, it means there is still some air inside the circuit, that must be removed. The cycle must be repeated until the pressure is completely stable.
Once the air bubbles are totally removed, the temperature can be raised, setting an lower set point on the thermoregulator compared to the nominal final working temperature, checking that the pressure indicator is stable. The operation must be repeated until the final working temperature is reached.
The first start-up of a complicated industrial thermoregulating unit working with diathermic oil can even take a whole working day, but it’s very important to carefully achieve it. In particular, the first heating up run must be done gradually and very slowly, to ensure that there is no air bubbles within the hydraulic circuit, avoiding serious damages on the mechanical components of the unit, such as mechanical seals and heating resistances.