NEW OKITU PLANT

Gisborne Herald, Volume LXXIV, Issue 22510, 13 December 1947, Page 8

NEW OKITU PLANT

LATEST ]N DESIGN MILK PASTEURISATION USE OF REGENERATION Gisborne’s milk supply is now largely passing through the Okitu Co-operative Dairy Company’s latest type oL’ city milk A.IW. high-temperature short-time treatment plant, the installation of which was completed this week. It is the first instalment, of this design of plant in New Zealand. The whole of the unit is British and is constructed in stainless steel. The milk is pumped from the receiving vat through a unit which pre heats the milk regeneratively to 130 degrees. The process of regenration relates to the heating of the cold milk with hot milk between plates in the unit and conversely the use of cold milk to bring down the temperature of hot milk. After this pre-heating the milk then passes through double-sided internal filters and away to the final heating section. The filters consist of two thicknesses of filter cloth to ensure that no foreign matter can possibly remain in the milk. Automatic Diversion Until a temperature of 161.5 degrees, as required by the regulations, is attained the milk is by-passed through a diversion valve to a balance tank automatically. On reaching the pasteurisation temperature of 161.5 degrees it automatically flows back through the unit for the final cooling. This flow diversion valve is the safety device against tne passing of any unpasteurised milk through the full process. Should the milk temperature on the milk recorder drop half a degree, that is from 161.5 degrees fo 161, then the flow diversion valve automatically comes into action, warning signals are given and the fall is recorded on the control chart, which is regularly inspected by the appropriate authorities. It should be stressed that it is improbable, under normal conditions, that any fluctuation of temperature of the milk would take place as everything is controlled by the latest thermostatic methods. A feature is that during treatment the milk passes in a thin film between Staybrite steel plates which ensures quick, even heating and cooling, _ the latter being carried out with chilled water provided by a newly-installed automatic water chiller. No Airborne Infection Another feature of the A.P.V. machine is that it is impossible for any airborne infection to take place during the treatment as no milk comes into contact with the air from the time it leaves the milk receiving vat until it is poured from the bo tie in the consumer’s home. That ensures that consumers are getting a perfectly safe pasteurised milk. The final cooling is carried out by chilled water circulating between stainless steel plates, which brings the milk down to 38 degrees before bottling takes place. At present the unit has a capacity of 600 gallons per hour and this can be increased, if necessary, to a maximum capacity of 2000 gallons per hour by the addition of extra plates in the various sections. The plant was obtained through the agency of Messrs. J. B. Mac Ewan and Company, Limited, Auckland, and a new bottle washer and bottle filler to synchronise with the new treatment plant are expected to arrive in New Zealand shortly. The new bottle filler will be suitable for capping with aluminium caps when the special bottles required for that purpose are obtainable in New Zealand.