Features of Cip System

Following features are noteworthy in CIP systems:

 

i. The heating arrangements

Usually steam at 2 to 3 Kg/sq.cm. pressure is used for heating the CIP tanks. For this steam is supplied in the coils in the tank or jacket of the tank. It has been observed that steam heating provision in tanks results in water evaporation and creates unhygienic conditions and as such results excessive loss of heat. At the same time due to loss of temperature during supply from tanks to place of cleaning,there are chances of non-achievement of desired temperature in for the CIP of equipment. This problem is corrected in the modified CIP system, in which various solutions are heated to the required temperature in a plate heat exchanger placed nearer to processing equipment/vessel. This type of arrangement is not only energy efficient but on the other hand results effective cleaning due to better control over the temperature of cleaning solutions.

 

ii. The preparation of solutions

Following steps are taken for preparing various solutions in the tanks of CIP system:

•  Drain the dirty solution from the tanks and clean thoroughly.
•  Feed the tanks with required quantity of water by opening water line valves
•  Dose various detergent/acid/sanitizers in measured quantity in the respective tanks to get proper concentrations.
•  Open steam valve in the water tank, if hot water is required, otherwise not.
•  Heat the alkali and acid tank to achieve required temperatures.
•  Alternatively in the modified system where plate heat exchanger (PHE) is used for heating the solutions, pass the particular solution through the PHE and re-circulate till required temperature is achieved. Now forward the heated solution for the purpose of cleaning.

iii. Operation techniques of CIP system

The CIP system is operated with following three techniques, in which the solutions are taken from tanks, heated to a particular temperature and circulated for cleaning for desired period.

Manual System: In this type of system all the valves, pumps are operated manually by a trained operator.

Semi Automatic CIP System: This type of system are provided with pneumatic valves and operated through skilled operator and/or time/temperature control relays known as timer.

Automatic CIP System: In this type of CIP system all operations including maintenance of concentration, selection of tanks, cleaning equipment, duration and temperature of solution is done automatically as per the set cleaning programme of the plant. Since cleaning of milk equipment, process circuit and vessels are the repetitive in nature; hence use of automatic system demands application of automation. This type of system makes mandatory the application of two principles;namely, 1) proper engineering of the product piping system and a CIP supply-return system, and 2) the installation of a permanently located recirculating unit. The automatic system consist of a) program sequence controller to time all portions of the cleaning cycle, b) adjustable set-point temperature controls to provide variable supply-line solution temperature, c) air-operated solution flow-control valves, and d)detergent feed equipment to transfer chemicals automatically into the system as required for the cleaning processes.

 

 iv. Standalone type cleaning-in-Place system

There are number of dairy equipment in which centralized CIP system is not used and other special type of CIP arrangements are inbuilt or provided during installation.Milk/cream pasteurizer, milk evaporator/condensing plant are some such most prominent examples. In this type of process equipment similar process as discussed above is carried out. However, these equipment are cleaned by their own flow circuit. The balance tank is used for taking water, dosing chemicals and feed pump to circulated the desired solutions of required concentration for certain period. The heating system of the equipment is used for heating the solution. One of the CIP circuit of milk pasteurizer (PHE) is depicted in the Figure.

CIP Circuit of Milk Pasteurizer

LEGENDS: C stands for chilling section, 1 stands for Regeneration-I, 2 stands for regeneration-II, H stands for Heating section,
Represents Cooling medium line, which is shut off during CIP, & Represents heating medium line (steam or hot water heating).

The solution after heating to required temperature in heating section goes to holding and then passes through FDV.

The CIP of milk pasteurizer is done mainly in three flow patterns; viz: a) by using regular product supply and discharge line, b) simple method of using split flow with few changes, and c) providing highest holding tube velocity.In the split flow technique,

In the split flow technique, various section of PHE have circulation of solution without production of excessive pressures and prevent excessive leakage through gaskets. In this about three times solution is forced through the plates as compared to the regular flow path, causing better filling of plate and air purging. However this requires high capacity of pump to force larger volume and need special size of inlet and outlets.