What do I have to consider in the place of installation of the NLPA150 / NLPA250? Which conditions must be met?

Generally, the light ends removal system must be installed at least 2m above the highest point (expansion tank) to operate it using gravity. The nitrogen for the light ends removal system flows through a nitrogen anti-cavitation valve from the expansion tank.
Because the passive light-ends removal works without its own pump, the return flow and the flow of the distillation tank must be connected on the intake and outlet side of the primary circulation pump (in the return flow of the heat transfer oil heater).

It should be connected to the flow line of the thermal oil system. The flow and return flow with the primary circulation pump between them.
With this, pay special attention to the following interface parameters:

Connection valves – thermal oil (inlet)Nominal diameter DN25
Connection valves – thermal oil (outlet)Nominal diameter DN50 (NLPA150) / DN80 (NLPA250)
Cooling water valvesNominal diameter 3/4´´ (NLPW250)
Thermal oil – flowmin. 1 bar + static height of the expansion tank +
overpressure due to nitrogen blanketing
Thermal oil – return flow–
Recommended inlet temperature 250 °C
Nitrogen supplyVia expansion tank
Air-cooled (NLPA150 / NLPA250)15 – 30 °C
Cooling water (NLPW250)2 – 4 bar

How does the cooling of the condenser work for the NLPA? Are there any differences?

In case of the passive light ends removal with the NLPA150 / NLPA250, the condenser is cooled by an air-cooling system. Because it is installed on the building roof, the ambient temperature, which usually is between 15 °C and 30 °C, cools down the condenser of the light ends removal system.

Beside the air-cooled variant, the NLPA250 unit is also available as water-cooled variant (NLPW250), which makes it possible to use the system up to an oil volume of 110,000 litres. However, this solution is preferably applicable for smaller systems.

Does a passive light-ends removal system pay off as retrofitting or better not?

Generally, the integration of a light ends removal system in a thermal oil system is always an advantage. Due to the relatively simple, technical design (no additional pump, no additional control unit), pure original cost is lower. However, the fine adjustment of the system and the additional steel structure for the installation must be considered for the total cost estimate as well.

Due to its flexibility in integration and installation, an active light ends removal system is therefore optimally suitable for retrofitting. Because it has an integrated pump and its control system, its integration in existing system can be realized more efficiently.