Recovery of contaminated industrial refrigeration circuits

The challenge

A food industry company in Valencia was experiencing repetitive compressor burns in their refrigeration installations. Over a period of 18 months, they had replaced three semi-hermetic compressors, with a direct cost exceeding 15,000 EUR per replacement, plus losses from production stoppages and risk to stored product.

The initial diagnosis revealed the problem: acid contamination in the refrigeration circuit. POE (polyolester) oils, used with HFC refrigerants, are highly hygroscopic. Moisture ingress into the circuit — probably during a previously poorly executed repair — caused the oil to degrade and form acids that attack the compressor motor windings, causing internal short circuits and successive burns.

The solutions previously applied by other installers — compressor replacement, dehydrator filters and new oil — only masked the problem. Residual contamination in the piping, evaporator and condenser re-infected each new compressor within months. The entire circuit was compromised.

The solution

Acoval intervened with the certified Fri3oilsystem process, a technology specialising in cleaning and decontaminating refrigeration circuits without needing to dismantle the installation. The procedure removes acids, combustion residues, metallic particles and degraded oil from the entire circuit, including pipe sections, heat exchangers and valves.

The process was carried out without releasing refrigerant gases into the atmosphere, recovering the existing charge in compliance with Regulation (EU) 517/2014 (F-Gas). After cleaning, the residual acidity of the circuit was verified by chemical test, confirming levels within the acceptable range. The system oil was replaced and a deep vacuum dehydration was performed before refrigerant recharging.

The new compressor was installed on a completely sanitised circuit, accompanied by a preventive maintenance plan that includes periodic oil analysis and circuit moisture control. More than 12 months have passed since the intervention without incidents. The total cost of the recovery was less than the price of a single one of the three compressors that had been replaced previously, demonstrating that correct diagnosis and an appropriate technical solution are always more cost-effective than repeatedly replacing components.