Study of Milk Cream Separator
To study the parts of mechanical cram separator.
To assembling and dismantling of the cream separator.
Cream separation is a phenomenon by which the milk is separated in to cream and skim milk by centrifugal and gravitation force. The centrifugal force is thousand times greater than gravitational force. The milk enters the rapidly revolving bowl of the separator. It is then acted upon by gravitational and centrifugal force. The inflow of milk is channelized to the outer wall of the bowl and fills it from outside towards the centre. The centrifugal and gravitational forces keep on continuously and act upon to partition the serum and cream. The milk serum has higher specific gravity (1.036) than that of fat (0.9). Obviously serum is thrown towards the outer periphery and channelized to skim milk out let, while the cream is channelized to the central core and forced out through cream out let, while the cream is channelized to the central core and forced out through cream out let. There are different methods i.e. shallow pan methods, deep pan method, water dilution of cream separation. These methods which have poor efficiency and are used in the absence of mechanical device.
Air tight separation is improved by mechanical method of cream separation. Separation occurs in a hermetically sealed system thereby milk is kept out of contact with air with minimum foaming of skim milk; mechanical cream separation is common and is in operation on various scales.
Mechanical Cream Separator:
In mechanical cream separation the cream separator is the major machine used, it may be hand operated or power operated.
Study of Cream Separator: Construction: The modern centrifugal cream separator consists of
I. A bowl which can be rotated at a high speed (5000-6000rpm) by means of suitable gears and power transmission mechanism.
II. Arrangement for supplying milk to the bowl.
III. Removing the cream and skim milk.
IV) Driving the machine:
I) Bowl parts:
1. Rubber ring or Gasket: It fits in the bottom of the bowl base and makes the bowl leak proof.
2. Distributor: It distributes the milk into the three notches at the bottom periphery.
3. Bottom disc: It is different from the rest of the disc. It has projections on the outer as well as on inner surface and has three holes. It is also called as separating disc.
4. Intermediate disc: they are 6 to 7 in number. They are similar to the bottom disc expect that these discs do not have projections on inner side. They have projection on the outer periphery only. These discs have three holes. The increased number of discs increases the efficiency of separation.
5. Top disc: This is very important part of the bowl. This is also called as separating or dividing disc. The connection between the skim milk and skim milk outlet is made possible by this disc. The disc has an outlet for the cream in its neck. During separation the cream near the axis of the bowl oozes out from the cream outlet. This disc has screw at its neck. The thickness of cream can be adjusted by adjusting this screw.
6. Bowl Hood: It fits over the top and covers the whole bowl parts.
7. Bowl spanner: Its function is to tighten the bowl nut.
II) Arrangement for Supplying Milk to the Bowl:
1. Supply can: It holds the milk to be separated.
2. Faucet: It is used for allowing the flow of milk from the supply can into the bowl.
3. Regulator: It regulates the flow of milk into the bowl.
4. Float: It allows only a definite quantity of inflow of milk into the bowl, through the regulator.
III) Removing of Cream or Skim Milk:
1) Skim milk outlet: The skim milk from the bowl moves between the dividing disc and inside wall of the bowl. At the top, space is provided between to disc and bowl hood, which connects with the skim milk outlet. The skim milk is let out through this cover.
2) Cream outlet: The cream coming out from cream screw located on the top disc is trapped in the cream cover and is let out.
IV) Driving the Machine:
1. Spindle rod: The bowl rests on the spindle rod. The spindle rod has a suitable gear which is engaged with crank gear.
2. Crank handle: The machine is revolved with the crank handle at the speed indicated the manufactures. Generally 60-70 revolutions per minutes are sufficient to develop the speed.