USE OF REFRIGERATION

Hawke's Bay Herald-Tribune, Volume 81, Issue 43, 13 November 1937, Page 2

USE OF REFRIGERATION

Address tio Hastings Rotarians

PR1NC1PLES OUTUNED

An explanation of the principles of refrigeration was given to the Hastings Rotary Club at the weekly meeting yesterday by Rotarian J, J. Hill. - Ojhe address was illustrated by means of a small refrigerating plant and a demonstration of the aetion of a ghs now commonly used in the proeess. Decomposition in foods, stated the speaker ,was due to the action of bacteria, the cffects pf which wore most apparent dn temperatufes of ahove 50 degrees. That this had 'been xealised in the early days was cvidenced by the tale of the Caesars who employed slave trains to bring snow from the mountains for use in cooling wine, it being realised that from the point of view of both comfort and healtih, refrigeration was desirable. " •. The first necessity for a gotd refrigerator was a hermetically-sealed cabinet. ' • • ' , * The speaker explained * to his andience, with the help-.of a small refrigerating motor, tho pi*iheiples governing refrigeration, (ind gave a brief survey of the advanc6s " made in the process sinee its firgt 'practical ,use. . Ammonia ahd sulpliur dioxide, wero the. ' rst mediums used in refrigeration. The latter was a good refrigerant, but had the dahger - that if there was any fault in the taaehinery permitting the air to como' in'^eontact With the gas, this would resnlt in the formation of a sulphurous acid '-which destroyed bearf ings and cylinder head. Methyl chloride 'was then tried, being followed finally by other methane- gases. A demonstration of the action of one of tho latter ghses was given. The gas, eompressed 'ifi a; small cylinder, was released into a glass, and boile'd furiously a ' the teihperature of the room. Water poured into the liquid in 1%, glass was immediately frozen.