CLEANING MACHINES

Taranaki Daily News, 15 September 1934, Page 24 (Supplement)

CLEANING MACHINES

EXPERT TRACES METHODS HOT WATER AND CAUSTIC SODA. THE NEED FOR EXTREME CARE. “The cleaning of milking-machines by what is now commonly termed ‘the boil-ing-water and caustic-soda method’ has been extensively practised for a number of years, and has stood the test of time. No other known method has proved so satisfactory with respect to sanitary efficiency combined with simplicity, speed and cheapness in operation,” writes Mr. J. W. Smith of the Dairy Division in the New Zealand Journal of Agriculture. The more compact the layout of the machine the greater the ease in cleaning. Various types of machines are in use, and of these “the . releaser and vacuum-tank” type is the most common. A few comments about the layout of this type of machine will serve to indicate how the method of cleaning can be usually applied to the best advantage. The main milk-pipe running through the shed should not be placed higher than is really necessary, and if possible should lead directly into the releaser without elevation. It should be well supported by brackets at distances close enough to prevent sagging and have, a fall towards the releaser of at least lin. to each 7ft. of length. The main vacuum pipe should have a similar fall towards the vacuum tank, as should the breather pipe from the pulsator to the releaser. The pulsation or air-pipes should be so installed as to have a 1 fall towards the screwed end. Piping installed in this manner is easily accessible for cleaning, and effective draining is ensured. THE' RUBBERWARE PARTS. Rubberware of first-grade quality is the best and cheapest to use. Tubing and inflations, when new, possess a very smooth inside surface, and this condition can be maintained for a long period, provided the method of cleaning is properly carried out. Spiral brushes or metal scrapers should not be used for el paring the inner surface of rubber tubing, as they cause scoring and roughening of the surface, and create lodgingplaces for deposits of milk and germs, with disastrous results both to the rubber and the quality of the milk. The principal requirements are:— (1) An adequate clean cold-water supply. (2) Suitable for providing sufficient boiling water for the cleaning of the machine after each use, such as a copper, steam boiler or efficient electric heater.

(3) A metal bath or tub of suitable size, some large buckets, scrubbingbrushes, a ball of horse-hair or a small pipe -traveller hair brush, and an ample supply of caustic soda. (4) A dairy thermometer registering to 212 degrees F. or a few degrees over. For cleaning cans, separator parts, etc., a supply of washing-soda should be provided.

The correct strength of the solution ,to use is one full teaspoon of caustic soda to each four gallons of boiling water. If this strength is adhered to, and its use immediately followed by rinsing out with at least double the quantity of clean boiling water, no harm will come to the rubber or other parts of the plant. The procedure is as follows:—? (1) After starting the machine and before commencing to milk, draw some clean cold water through each set of teat cups, taking care that the water does not run into the milk vat or cans. This rinsing with cold water prevents adhesion of milk to the piping. (2) after milking and before applying the boiling caustic soda solution draw some cold water through each set of teat cups in order to.rinse out any milk remaining in the system. Failure to use cold water before the application of the boiling caustic soda solution will result in the gradual formation in the milk passages of a hard scale, commonly called milkstone.

(3) Wash off aL dust from the outsides of the teat-cups and rubber tubing with a solution of warm water and caustic soda and well' rinse with hot water.

(4) Put the releaser out of milking action by stopping the pulsator at a point that will cause the outside flap of the releaser to seal tight. Then draw through each separate set /of teat-cups at least one gallon of the boiling caustic soda solution. On drawing it through the set farthest from the releaser carefully lift the flap or plug at the end of the main milk pipe and insert a sixinch length of plaited horse hair or the pipe-traveller brush, retaining hold of it until the vacuum pressure organises, and simultaneously remove the plug for a moment and allow the horse hair or brush to whisk into the releaser. The releaser becomes full, and the overflow travels into the vacuum tank. Next, place an empty bucket under the releaser, break the vacuum by removing the plug from the end of the milk-pipe, and the contents of the releaser discharge into the bucket. Then replace the pipe-plug. REMOVAL OF SOLUTION. (5) To remove all traces of the soda solution, immediately draw through each set of teat-cups at least two gallons of clean boiling water. Both the soda solution and boiling water are applied with the best results by dousing the cups in and out of the liquid, about three-quar-ters of the time in and one-quarter of the time out. The resultant inrush of air quickens the flow of the liquid, and causes it to surge with a scouring action through the piping. The quantities of the boiling liquids should be sufficient to fill the system and overflow the releaser by at least one gallon, thus cleaning the pipe between the releaser and vacuum tank. In addition, as a result of stopping the pulsator, the hot water is retained in the system, which thereby is heated to a maximum heating temperature. The vacuum and air system should next be cleaned.

(6) Detach the air rubber tubing from each claw and place the ends in boiling caustic-soda solution, and draw up at least a quart each, then rinse with clean boiling, water! The water will pass through the tubing under the pulsator-slide and into the main vacuum pipe and into the vacuum tank. (7) Next detach the air-pipe from the rubber tube connecting it to the outer chamber of the releaser, and draw through about a quart or more of the boiling soda solution, and then some clean boiling water. These fluids will also travel to the vacuum tank. The cleaning to this stage is as much as need be done under vacuum.

(8) Before stopping the machine, allow the teat-cups and all air-pipes to draw air for a few moments. Remove and replace the plug on the main milk-pipe two or three times to cause an inrush of air to carry away all surface moisture and to leave the machine dry and sweet.

(9) Leave all taps and ends open to

allow of the free circulation of air, then stop the machine. (10) Next scrub and scald the vacuum tank.

(11) Dismantle the releaser and scrub and scald it.

(12) Disconnect the teat-cups and rubbers from the milk and air pipes and place them in a dry airy clean place protected from dust and the rays of the sun.

It is essential that the temperature of the hot water used be not less than 200 degrees F. and preferably boiling—2l2 degrees F. A thermometer should be used to check the temperature. Too little boiling water is often used, but rarely too much. To produce milk of good hygienic quality milking-machines should be regularly cleaned as outlined each time after use. With practice the average machine can be cleaned in about twenty minutes. DANGER OF “MILKSTONE.” If a milking-machine is not regularly flushed with cold water to remove all traces of milk prior to treating with hot cleaning solution or steam, a hard deposit readily forms inside the pipes. This “milkstone,” as it is called, enables germs to multiply, and special steps must be taken to get rid of ■ it. The simplest method is to use a weak solution of spirits of salts (hydrochloric acid), promptly, followed by liberal rinsing . with hot-water soda solution. The procedure is to dismantle the piping and prepare a solution of spirits of salts in the proportion of one part of spirits to three of water. In some cases a stronger solution may be required. To each 7ft. length of piping use Boz., or about a breakfastcupful. Plug one end of the pipe, pour in the solution, then plug the other end. Allow the solution to remain in the pipe for about thirty minutes, revolving the pipe occasionally to ensure distribution of the solution so as to soften the scale. Remove the plugs and clean the pipe with hot washingsoda solution and a tight-fitting hard brush; then rinse with clean boiling water. This treatment, properly applied, will leave the surface clean and bright. The “boiling-water and caustic-soda method” of cleaning, properly applied, leaves the milking-machine in a satisfactory sanitary condition. A further improvement is still possible by afterwards subjecting the inside parts of the machine to low-pressure steam for about five minutes to effect sterilisation.

Steaming alone will do harm rather than good, since, if the machine and utensils are not first thoroughly cleaned to remove all traces of milk, the application of steam (or even boiling water) not preceded by flushing with cold water will have the effect of causing hard deposits of milkstone to form in the machine. Such deposits accumulate from day to day and harbour countless millions of bacteria which resist prolonged efforts to destroy them. It should not be thought that the use of steam alone provides a short-cut to cleaning a machine. Proper cleaning with cold water, boiling caustic-soda solution, and boiling water should be carried out before steaming. Sterilisation with steam provides the finishing touch, and is the best possible safeguard for quality. For sterilising dairy utensils steam may be generated in a small pressure boiler, which can also be used to provide ample hot water. Such pressure boilers have the advantage of possessing ample reserve of pressure to force the steam to the farthest end of the milkingmachine pipes. During the last few years a variety of heating plants have been designed to provide readily an ample supply of both boiling water and steam by burning rapidly wood, coal, j etc.