what is Clean In Place machines?

CIP is an acronym for Clean In Place, which means cleaning in place, cleaning equipment without changing its location.

As a food, dairy, or beverage processor, you know the importance of maintaining a sanitary process environment to ensure product quality and purity. That's where a good clean-in-place (CIP) system comes in.

CIP cleaning cleans equipment and controls microorganisms and is widely used in food, beverage, and pharmaceutical companies.

The cleaning method corresponding to CIP is COP, Clean Out of Place, which means that the equipment is dismantled and cleaned.

Clean Out of Place is a method used when parts cannot be cleaned in place and removed from the process. Typical process parts cleaned in the area in parts washers and cabinet cleaners include hoses, fixtures, fittings, weighing drums, and other disassembled process parts.

Cleaning Principle

By applying thermal, mechanical, and chemical energy to the cleaned object's surface dirt, the cleaned equipment's effective cleaning is achieved within a certain period through the interaction of mechanisms such as dissolution, thermal, mechanical, interfacial activity, and chemical action.

Cleaning theory model - TACT model, that is, the cleaning effect of the four elements of the model (expressed in the formula)

CR=Ti+A+C+Tc

CR: cleaning effect, % is 100%.
Ti: time, mainly contact with the cleaned surface, the time of action.
A: mechanical role, generally more than 50%, mainly pressure, flow rate, etc...
C: chemical role, mainly cleaning agent type and concentration, etc...
Tc: the role of temperature, mainly the temperature of the cleaning agent, with the type of dirt and viscosity related.
TACT four factors affect each other and complement each other; when an element is not enough, it needs to be supplemented by other components.

1: Time Ti
Generally speaking, the longer the cleaning time, the better the effect. In industrial production, the production must ensure the production rate, usually cleaning time for 2 to 3 times the full coverage time. The entire in-situ cleaning process of each step, the cleaning time as the running time.

2: Mechanical action A
The mechanical role occupies more than 50% of the full cleaning effect; it needs to focus on ensuring the cleaning product.

(1) flow rate.
For equipment, tanks need to use the spray ball, pipeline valves, etc. need to ensure that the fluid is in a turbulent state.
Generally, ensure that the cleaning flow rate of about 1.5m / s does not exceed 3m / s. 1.5m / s belongs to the economic flow rate of the fluid, priority is given to.
Recommended range of Reynolds number.
Pipe fittings cleaning: Re＞30000
Vessel wall cleaning, cleaning fluid flowing down the wall: Re＞200
Rectangular cylinder, cleaning fluid: Re＞7500
Note: The flow state of the fluid.
    Laminar flow (Re < 2000)
    Transitional flow (2000 ≤ Re ≤ 4000)

    Turbulent flow (Re>4000)

(2) Pressure
Very easy to clean the tank: 1 ~ 3bar
Easier to clean the tank: 2 ~ 6 bar
More difficult to clean the tank: 6 ~ 10bar

Very difficult to clean the tank: > 10 bar

(3) Flow rate
Calculation of tank surface area: 0.24~0.72m3/(m2*h)
Tank perimeter calculation method: 1.5~3.5m3/(h.m)

Rectangular tank, cleaning solution: Re＞7500

3: Chemical action C
Commonly used chemical cleaning agents are: acidic, alkaline, neutral.
According to the different dirt, there are several selection principles as follows
(1) grease class
Surfactants (penetration and emulsification)
Lye (dispersion effect)
Strong alkali (saponification)
(2) Sugar carbohydrates
High-temperature water dissolution effect
(3) Proteins
Lye solubilization
Acid solubilization
(4) Starchy carbohydrates
Lye solubilization
Acid solubilization
Decomposition of amylase

4：Temperature
In a specific temperature range, temperature increases every ten ℃, the chemical reaction speed increases 1.5-2 times, cleaning speed, dissolution speed will be supplemented with, if the weather is too high, the residual protein components denaturation, resulting in more difficulty to clean equipment. So it is not. The higher the temperature, the better.
In general: when the temperature reaches 80 ℃, the temperature rises again, cleaning time no change, so the cleaning solution temperature is generally controlled at 60 ~ 80 ℃

CIP process and calculations

CIP process calculation mainly involves the cleaning process, CIP tank, transfer pump, heat exchanger, cleaning pipe diameter, and other equipment selection and analysis.

1. Cleaning process

(1)Three-step method
(2) five-step method
(3) seven-step method

The principle of choosing the cleaning process.

¶ General process uses 3-step cleaning (water rinse - alkali rinse - final shower)
¶ Aseptic dispensing process adopts 5-step cleaning method (water rinse - alkali rinse - water rinse - acid rinse - final shower)
¶ Water rinsing adopts drinking water or recovered final shower water; water temperature can be adjusted according to different residues, generally control the water temperature at 60~80℃.
¶ Alkali washing adopts 2% NaOH solution, and the alkali washing recovery solution can be recycled under the premise of no cross-contamination
¶ Acid washing adopts 2% nitric acid
¶ final shower using purified water, sterile solution using injection water

2. Transfer pump size determination

There are two calculation methods: the perimeter of the tank to be cleaned and the cleaning of the internal surface area of the tank method; the following is a specific example to introduce these two calculation methods.

Example: known to be cleaned tank diameter of 1500mm, barrel height of 1500mm, try to determine the size of the required CIP cleaning system transfer pump.

(1) by circumference method
The empirical value is: 1.5~3.5m3/(h.m)
q=π*D*η
q: pump cleaning flow m3 / h
D: diameter of the container to be cleaned m
η: empirical value, 1.5~3.5m3/(h.m), the small diameter is 1.5 large diameter is 3.5

q=3.14*(1500/100)*1.5≈7m3/h

(2) By internal surface area method
The empirical value is: 0.24~0.72m3/(m2*h)
q=A*η
q: pump cleaning flow m3/h
A: the inner surface area of the container
η: empirical value, 0.24~0.72m3/(m2*h), the small diameter is 0.24 large diameter is 0.72
A=12.2m2 in this example
q=12.2*0.5≈6.1 m3/h

Take the large value of the above two calculation methods, q = 7m3/h, rounded to the common specifications of the pump, then q = 10m3/h

3. The head of the pump is determined

H=(h1+h2+h3)*100
H: cleaning pump head m
h1: the pressure required to clean the ball Mpa
h2: the height of the tank to be cleaned caused by the pressure loss Mpa
h3: pipe pressure loss Mpa
General cleaning ball pressure required for 0.25Mpa

H=(0.25+0.1*1500/10000+0.05)*100=31.5m

4. Cleaning tank size determination

The number of cleaning tanks can be divided into single tank CIP, double tank CIP, three tanks CIP, four tanks CIP, etc., can be configured according to the actual needs. Usually based on experience: the volume of the configured CIP tank to ensure that the amount of 10 minutes cleaning determines the size of the CIP tank.
V=q*10/60
q: pump flow m3
V=7/6=1.2m3

Take a certain amount of rich, here take the CIP tank size of 1500L.

5. Heat exchanger heat transfer area to determine

Divided into two parts of the calculation, one is to heat the solution in the CIP tank to the process temperature; the second is the need to reheat due to a drop in temperature during the cycle.

(1) Heating the solution in the tank
It is calculated by heating from room temperature 25 ℃ to a maximum of 80 ℃, the available heating time of about half an hour to an hour, here to half an hour to calculate.
Heat exchanger heat load, assuming the use of water circulation cleaning.
Q1=cmΔt
c: specific heat capacity, Kj / (kg - K), here 4.2
m: the mass of the heated medium, kg
Q1=1500*4.2*(80-25)/(30/60)= 693000Kj/h
m1=Q1/(k*Δt)
m1: heat exchange area m2
K: heat transfer coefficient, generally for the plate heat exchanger, here take 1500 W/(m2-℃)
Δt: average heat transfer temperature difference ℃
I am assuming a heating steam pressure of 0.3Mpa, then the corresponding temperature of 143 ℃, the average heat transfer temperature difference of 87.6 ℃ (calculated by countercurrent).
Then the required heat transfer area
m1= Q1/(k*Δt)=693000/(1500*87.6)/3.6≈1.5m2
Taking the safety factor of 1.2.

Then the heat exchange area is 1.5*1.2≈1.8m2

(2) Circulation process heating
Assuming that the circulating return water temperature is 73℃, the required heat exchange area m2 is calculated according to the circulating time of 10 minutes, and the average heat transfer temperature difference is 66.4℃.
Q2=cmΔt=10000*4.2*(80-73)/(10/60)≈1764000Kj/h
M2=Q2/(k*Δt)= 1764000/(1500*66.4)≈4.9m2
Take the safety factor 1.2, then the actual required heat exchange area m2=1.2*4.9≈5.9m2

Comprehensive take m1 and m2 in the larger value, then the required heat transfer area of 5.9m2

6. Cleaning pipe diameter calculation

d=sqrt(4*q/(π*a*3600))*1000
sqrt: open square root
d: cleaning pipe diameter mm
q: flow rate of the pump m3
a: flow rate m / s, generally take 1.5
d= sqrt(4*7/(π*1.5*3600))*1000≈40mm

Advantages of a CIP system.

Minimize errors. Automatic cleaning reduces the chance of human error, which can lead to unsafe products.
Keeps employees safe. By adding a cleaning solution to the system, the chance of exposure to chemicals is reduced.
Longer production time: With less production time lost due to cleaning, more time is spent producing the product.
Product quality. Reliable and repeatable cleaning means sustainable product quality and consistency. Less contamination means fewer product recalls and higher brand confidence.
Save on utility costs. Reduced water and energy use through repeatable cycle control.


Sinofude is a Cleaning In Place Machines supplier with products such as marshmallow production line, popping boba line, hard candy dies forming line, etc.
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