Slovakia-based ABC Food Machinery recently installed a cooling system using an ammonia-ether mix (R723) for SlovTan Contract Tannery that saves over 744 metric tons of CO2e emissions and improves energy efficiency compared to the previous system, said Juraj Švingál, Manager for ABC, in a statement.
ABC makes compressors and assembles systems, all using ammonia (R717) or an ammonia mix as the refrigerant. R723 is a mixture of 60% ammonia and 40% dimethyl ether (RE170) and has a GWP of eight.
The tannery, located in Liptovský Mikuláš, Slovakia, requires the temperature of one room to be below 6°C (43°F) for the storage of 150 metric tons of fresh rawhide and another room kept between 22 and 26°C (72 and 79°F) for the storage of 45 metric tons of semi-processed shin leather. In addition, the ventilation requirements, especially during the summer because of tannery byproducts, had a “significant effect” on the cooling, Švingál said.
SlovTan Contract Tannery replaced its 12-year-old 100kW (28.4TR) HFO/HFC cooling system due to the EU F-gas Regulation and frequent breakdowns of the aging system. ABC installed the replacement during the winter of 2021–2022.
ABC met the company’s needs with “indirect cooling with direct evaporation of the refrigerant in a compact heat exchanger” in each of three chillers, linked to five glycol brine coolers (evaporators), Švingál said. The three independent chillers were installed outdoors with an overhead roof, using ABC’s Twineco 100P O543 compressors, each chiller providing 45kW (12.8TR) of cooling capacity with 2.9kg (6.4lb) of R723 and creating an outlet glycol temperature of -5 to 0°C (23 to 32°F).
Two stainless-steel coolers were installed in each storage room. In addition, a cooler installed in the hallway between the storage rooms provides pre-cooling, which had not been provided before.
Both rooms and the hallway are on independent cooling circuits with coolers mounted on a frame with an air condenser; they are connected in parallel to the antifreeze distributor and central circulation pumps, with individual oil circuits and oil separators.
“[We used] a dry expansion system with an electronic expansion valve [EEV] valve with precise step control,” Švingál said. The control system offers the use of one to three chilling units. “The operation of the [installation] confirms high efficiency with low energy consumption,” he noted.
In addition to the cooling priority, the chiller also maintains the desired heating temperature, ABC said.
R723 advantages
“Compared to pure ammonia, R723 refrigerant transfers oil better even at low temperatures and has the advantage of returning oil back to the compressor,” said Švingál. Just 0.04kg (0.09lb) of the mixture supplies 1kW (0.28TR) of cooling with lower condensation pressure at the same temperatures than ammonia.
“The demand for R723 is increasing,” said ABC in a statement in 2019 when the company said it currently sold one to two R723 systems a year. The company notes the refrigerant is not subject to the carbon emissions reductions of EU’s F-gas Regulation, has a stable, low price and is energy efficient over HFO systems.
Founded in 1992, ABC Food Machinery, is a family-owned company located in Bratislava, Slovakia, that supplies industrial and commercial heating and cooling solutions. The company offers “flexible and comprehensive” services for projects, including delivery, assembly, warranty and post-warranty services and remote management.
“Compared to pure ammonia, R723 refrigerant transfers oil better even at low temperatures and has the advantage of returning oil back to the compressor.”
Juraj Švingál, Manager for ABC
