JohnsonDiversey. CIP Cleaning in place. • The circulation of non foaming
cleaners without dismantling the equipment. • An automatic and systematic
cleaning of ...
CIP
Cleaning in place
• The circulation of non foaming cleaners without dismantling the equipment.
• An automatic and systematic cleaning of the inner surfaces of tanks, heat exchangers, pumps, valves and pipes.
JohnsonDiversey
CIP properties • Strong and hot solutions can be used. The heat, the chemistry and the mechanics can be sustained long. • The solutions can be reused. • Can be automated and reproducibility is good. • Investment in equipment is high. • The mechanics are not always sufficient
JohnsonDiversey
JohnsonDiversey
Flow Rate vs. Flow Velocity
volume per second
1 second
inside diameter
v= Where,
4.Q 2
3600.d .∏
v = flow velocity Q = flow rate π = pi (3.1415,…) d = inside pipe diameter JohnsonDiversey
meters per second m3 per hour dimensionless meters
Velocity vs flow
Pipe size
1.5 m/s velocity
2.0 m/s velocity
Litres / sec
Litres / sec
ID mm
DN 50
47
2.6
3.5
DN 80
77
6.9
9.3
DN 100
97
11.1
14.8
DN150
147
25.5
33.9
JohnsonDiversey
Vertical vessel flow requirements - sprayballs
Vertical vessels
For most vessels, the sprayball delivers a uniform quantity of solution to the upper circumference of the vessel Based on soil level, deliver a given quantity of solution to a unit length of circumference - called liquid loading:
Don’t forget about flow OUT of vessels
JohnsonDiversey
Sprayball Placement
180 - Θ Depth of Sprayball = Dome Height + D ⋅ tan 2 Depth of Sprayball
Dome Height
140º
Sprayball
Where, θ = angle of coverage, D = diameter of vessel, Dome height
degrees meters meters
Dome Weld NOTE: This is valid for simple vessels without obstructions. Additional sprayballs may be required.
JohnsonDiversey
example
100 gpm
15’
6” dia. JohnsonDiversey
Sprayball pressure Sprayball pressure is critical
Generally in the range (1.0) 1.5 - 2.5 (3.0) bar Too little pressure and the vessel walls are not reached Too much and the spray atomises reducing mechanical action Larger sprayballs with larger hole diameters can operate at higher pressures without atomising. All sprayballs have specified flow / pressure curves
JohnsonDiversey
JohnsonDiversey
Vertical vessel flow requirements - sprayballs
Flow as a function of diameter and soil
Q
R
=
D
QR = required flow rate
T
⋅ π
⋅ F
S
liters per minute
DT = vessel diameter
meters
p = pi (3.1415,…)
dimensionless
FS = soil factor
liters/(meter-minute)
FS = 27 for light soil conditions FS = 30 for medium soil conditions FS = 32 for heavy soil conditions JohnsonDiversey
JohnsonDiversey
JohnsonDiversey
High pressure rotary sprayheads Add impingement to the mechanical action Generally consume a little less water Have specific times to wet surfaces and impinge on them dependent on pressure and gearing Not very effective on larger vessels under 5 bar pressure
Use similar data to specify as sprayballs Use manufacturers recommendations Toftejorg have a computer simulation program called TRAX - use it
JohnsonDiversey
CIP Optimizing CIP optimizing is the process of minimizing the cost inputs of CIP cleaning
water effluent energy
chemical electrical heat CO2 production time
JohnsonDiversey
Optimizing drivers
CIP system design
clean circuits - no dead legs, no flow splits accurate and non competing instrumentation - conductivity monitoring no leaks
CIP program
correct CIP program philosophy CIP preparation sequence - correct conductivity starting point tidy CIP fluids interface management - always in lines never in tanks correct valve sequencing on monitor signals defined terminators each CIP step JohnsonDiversey
CIP optimizing - circuit volume
To predict CIP losses and costs we must know the CIP circuit volume.
This has nothing to do with the size of the CIP tanks.
It is the amount of liquid held up in the CIP headers and the vessel or line being cleaned.
To calculate the circuit volume for a line clean we need to know the diameters of the lines and the length of each line size.
To calculate the circuit volume of a vessel clean we need to know the line information and the dimensions of the vessel being cleaned.
JohnsonDiversey If there is other
too.
processing plant in the CIP circuit, we need to know it’s volume
Vessel Hold-up Volume Assume a 2 millimeter film thickness (0.002 m)
Dome Assume a completely wetted surface
Determine internal surface area
Dome Cylinder Cone
Cylinder
Cone
JohnsonDiversey
Vessel Hold-up Volume Area of Dome:
Area of Cylinder:
Area Dome = π r
2
Area Cylinder = π D h2
D
h2
Area of Cone
h1
NOTE :
JohnsonDiversey
(
)
1 2 2 Area Cone = D D + h1 2 4
π
r =
1 D 2
CIP optimizing - chemical loss management
Liquid loss for an efficient vessel CIP system is about 10% of circuit volume.
Line cleans can be run more efficiently than vessel cleans - as low as 5% loss.
Effective loss management depends on:
Effective Flow meter or conductivity interface detection. Managing liquid interfaces into pipes not vessels.
When managing liquid changes in vessels the program must be stepped.
New liquid to sprayball chasing old liquid into vessel. Over scavenge old liquid from vessel into return line. New liquid into vessel chasing old along return line to interface detector. First step should be volumetric and set for each vessel. JohnsonDiversey
CIP optimizing - chemical loss management
measured as % of concentrate detergent lost compared to the concentrate detergent in the CIP circuit volume
concentrate detergent lost is calculated by CIP tank, volume and concentration, before and after CIP
concentrate detergent in circuit volume calculated as the volume of solution held in the CIP circuit excluding the CIP tank at the starting concentration
JohnsonDiversey
The CIP flow is best circulated bypassing the CIP tanks with the heating and chemical dosing in line
