Freezing Faster and With Better Temperatures

Whilst with the installation of Realcolds SRT (Single Retention Time Tunnel) we expect large improvements in freezing efficiency by comparison to blast cells, our latest installation using CO² as the primary refrigerant has defied even our expectations.

NH3 have been very proud to receive an order and successfully complete the installation of another Realcold SRT Tunnel for Jose Hendrickx of Vriescentrale in Asten, Holland. As with previous installations, we expected large improvements in the usual areas such as efficiency improvements of refrigeration, fans, defrosting, core temperatures and freezing times, as well as the usual product presentation improvement, reduced labour and forklift operating costs.

The use of CO² has made a marked improvement on previous installations which we did not expect. The old R22 system and blast cells were removed and the Automatic Single Retention Time Tunnel installed in its place using exactly the same footprint but increasing their capacity to 185% of the previous system.

The differences observed initially between the old refrigerant and CO² are as follows.

Refrigerant	Air Temperature	Core Temperature	Freezing Time
R22	-40 degC	-18 degC	36 hours
R744	-40 degC	-35 degC	21 hours

In addition, the frosting and hence the defrosting requirement have been vastly reduced. This can only be down to the improved internal heat transfer in the refrigeration evaporators of CO² or R744.

It goes without saying that Jose Hendrickx is ecstatic with her new facility which has put her in the unique position of being in the forefront of export freezing from Holland for her clients and is receiving delegations from China and the Far East due to the improved quality of the products she is now producing.