This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol6", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
The Tanks (Fig. 87) may be here described, being both of same construction whether for small or large dairies, differing only in matter of size. For milk and cream purposes the following are required: The milk receiving tank, the separated milk tank, the milk supply tank for drinking purposes. They are made of strong tinned steel or copper sheets. The following are stock sizes approximately: -
The Pasteuriser has its own furnace, and is therefore heated independently of any boiler or steam-producing apparatus. A description of a pasteuriser driven by power will be found later on, and applies generally to all such apparatus. Burmeister & Wain's " Perfect" pasteuriser is capable of pasteurising milk or cream up to190o or 195°. The sizes are as follow: -
45° to 105°F.
45° to 165° F.
95 to 185° F.
The fresh milk is placed in the bowl-shaped receptacle, passes through the pasteuriser, and then rises by means of the pipe shown on left of figure to the Separator, which, as the name implies, separates the cream from the milk, delivering each one separately by its special spout. The illustration (Fig. 88) shows a "Perfect" separator by the same makers, which is fitted on a specially constructed stand, to which is fixed a shelf to carry a pail. This would require a floor space of about 6 square feet.
The separator itself may be placed on a table or any convenient place in the dairy, and would occupy a space of 1 ft. 3 in. by 2 ft., to 2 ft. 6 in. by 3 ft. 4 in.
These separators for hand power are made of different capacities from 13 to 110 gallons per hour.
For the good preservation of milk it should be cooled after passing through the separator, or when coming direct from pasteuriser. The cooling in all cases is obtained from cold water, which circulates inside the cooler whilst the milk descends from the pan on the top to the saucer at bottom, and thence by means of a tap into the receiving pail.
The conical cooler (Fig. 89) requires a floor or table space varying from 1 ft. 6 in. to 6 ft. 8 in. square, its capacity varying from 36 to 1000 gallons per hour; while the bracket cooler (Fig. 90) occupies even less space.
The separated cream when cooled and ripened is turned into butter by means of a churn, of which there are many forms on the market. The best known form is the barrel churn, as in Fig. 91. Whatever be the shape or form of the churn, the butter-making process is one of rotation, - in some cases by a horizontal movement, and in other cases by a vertical one, as in Fig. 91. The butter has to be broken up, so as to become granulated, by some means or other. In Fig. 91 the apparatus, one of Thomas Bradford's patents, which causes the desired result, is fixed on side as at a. When working this is placed inside the churn.
The space required may be roughly judged from the illustrations.
When the cream has been duly churned into butter granules it is thoroughly kneaded, in some cases by hand, but more generally by means of a butter-worker, after the style of Fig. 92. The butter is placed on the corrugated tray, which is then moved backwards and forwards by means of the helical roller. The water which is squeezed out of the butter falls into the draining trough, and thence into a pail or drain grid.
The butter, having been worked to a proper consistency, is removed to an ordinary table, where it is weighed, shaped, pressed, and stamped as may be required. A convenient table (Fig. 93) is that made by Messrs. Bradford & Co., which is 4 feet 6 inches long by 2 feet 3 inches wide. In centre of table is a small sunk box made to shape and size, as required, for the finished pat of butter. The butter is placed in this box and pressed together by means of foot treadle and hand lever. The table is of use both in small and large dairies, but especially in the latter.
The preservation of the finished butter, and its hardening in summer-time, may be effected by the use of a refrigerator cupboard (Fig. 94), which contains shelving accommodation, kept cool by means of the zinc-lined ice chamber and reservoir. These cupboards vary in size from 3 ft. 2 in. high, 2 ft. 5 in. wide, 2 ft. deep, to 5 ft. 9 in. by 4 ft. 10 in. by 2 ft. 7 in.
Although milk-weighing machines would scarcely be used in small dairies, it may be as well to deal with them here. Many devices are manufactured with the weighing mechanism below the tank. The tendency of the water and milk to trickle into machinery and so corrode the bearings is avoided in such appliances as that shown in Fig. 95, where the tank is suspended below the weighing mechanism. The weighing machines should be placed, as will be readily understood, in some convenient position where the milk is received, and again where the prepared milk is issued for selling purposes.