AS 1187:1996 pdf – Farm milk cooling and storage systems

AS 1187:1996 pdf – Farm milk cooling and storage systems.
(a) Cooling rate The cooling rate shall be as follows, depending whether collection is made on a daily or every-other-day basis:
(i) In the case of a milk cooling and storage system for daily collection, the mean temperature of a volume of milk equal to 600/o of the maximum rated volume of the tank, rhen added to the tank at a uniform rate over a period of 1.5 h. shall be reduced from 35°C to 4°C within 3.5 h from the time the milk starts to flow from the milking machine.
(ii) In the case of a milk cooling and storage system for every-other-day collection, the mean temperature of a volume of milk equal 10 30% ot the maximum rated volume of the tank, when added to the vessel at a uniform rate over a period of
1.5 h. shall be reduced from 35°C to 4°C within 3.5 h from the time milk starts to flow from the milking machine.
(iii) The rated capacity shall be specified on the compliance plate (see Appendix A).
NOTE: The cooling system may be so designed. that if the rated capacity is changed from cvcry-othcr-day collection to daily collection. the cooling systcm can he modified to meet the Standard, and he shown on the compliance plate.
(b) Holding The temperature of the milk after cooling shall not exceed 4°C. This holding temperature shall he maintained by the operation of the cooling and agitating equipment or by the insulating properties of the tank, or by both.
(C) Insulaling efficiency The thermal insulation of the tank shall be such that at an ambient temperature of 35°C the rate of rise of the mean temperature of the milk. initially at 4°C, shall not exceed 1°C in 4 h when the vessel is filled to the maximum rated volume and the milk allowed to stand without further cooling.
1.6.4 Iii an ambient temperature of 4OC The milk cooling and storage system shall operate for at least 2 h in an ambient temperature of 40°C without interruption, by protective devices and without overheating of the motors.
1.7 AGITATOR lRFC)RN1ANCI
1.7.1 (;eneral The lank shall he fitted with means for mechanical agitation of the milk in order to meet the cooling performance. as listed in Clause 1.6. and to mix the milk without causing overflow.
1.7.2 Cooling cycle During the cooling cycle the agitation system shall he set to start automatically and operate continuously (see Clause 2.5.6.4).
1.7.3 Non.cooling cycle During the non-cooling cycle the agitation system shall be set to operate intermittently for periods of at least 2 mm. at intervals of not greater than 6() mm (see Clause 2.5.6.4).
1.7.4 Performance The performance of the agitation system shall be such, that when any quantity of milk between 10% and 100% of maximum rated volume is allowed to remain undisturbed for not less than 30 mm and not greater than 60 mm.