Installation of a chiller that uses ammonia as coolant

2018 / Industrial risk analysis / Industries

The purpose of the study was the development of a risk analysis related to the installation of a refrigeration unit using Ammonia (R717) as a refrigerant fluid. The refrigeration unit has an ammonia hold-up of 32 kg and a cooling capacity of 429 kW and is installed inside a prefabricated box.

In order to contain any ammonia dispersions, the box is equipped with a fan, connected to a water scrubber for the absorption of any released ammonia.

Two ammonia detectors have been installed inside the box, with 1oo2 logic, with the pre-alarm threshold set at 25 ppm and the alarm threshold set at 500 ppm.

The ammonia discharged from the installed safety valves is conveyed to an knock down tank containing 1000 liters of water, which is bubbled through a sparger in order to improve its absorption.