REDUCING WATER USE THROUGHCLEANING-IN-PLACE (CIP)

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w This leaflet targetsany business wherecleaning of vesselsand pipework is anissue. It details thebenefits of usingcleaning-in-place(CIP) technology overmanual cleaning, howto optimise existingCIP systems andhighlights the costsavings that can beachieved through itsimplementation.

All cleaning processes aredesigned to remove ‘soil’ fromprocessing equipment, in thecase of CIP, this is done bycirculating a cleaning fluidthrough the equipment with littleor no disassembly. In addition,water use can be greatlyreduced and cleaningperformance improved byensuring spray devices aredesigned for purpose and withwater efficiency in mind.

CIP has advantages over manualcleaning methods, including:

• increased vessel cleanlinessdue to the use of welldesigned spray nozzles andthe type of chemicals andhigh temperatures employed;

• reduced water and chemicalconsumption;

• the opportunity to recoverand re-use fluids;

• high levels of automation.

EN89

4

TIP: Put a sub meter inthe water line to the CIP

set and monitor how much ituses.

Optimising CIPprogrammes

Existing CIP systems may not beoptimised, resulting in excessivewater and chemical use. Forexample, on a CIP set whichwashes different sizes of vessels,the timings may be set for thelargest one; add alternativeprograms for smaller ones to savetime and water.

Significant savings can be madeby reviewing your CIPrequirements. For example, check:

• flow rates and cycle times -Can these be reduced to savewater, chemicals, downtimeand energy?

• cycle volumes - Are theseadjusted according to thecirculation volume of the pipeor plant being cleaned?

• sequencing - Are all cyclesrequired? For example, do theyall need both acid and causticwashes?

• temperature - Do all cyclesrequire hot water?

Optimising the pre-rinse

• Ensure this rinse has cleared allthe loose soil.

• Rinsing in bursts (eg 10seconds on/20 off) andscavenging the fluidcontinuously to drain uses lesswater and rinses moreeffectively.

• High pressure/low volumespray heads are water efficient,but can take longer to rinse dueto their spray pattern.

TIP: Under-rinsing willcontaminate the dilute

detergent and means thatfurther rinses are required later.

Optimising the detergentwash

• Accurately control thedetergent concentration.

TIP: Caustic detergentsmay not mix well and

settle in the tank and over-concentrations are hard to rinse.

• Acidic detergents rinse moreeasily than caustic ones, savingwater; adjust CIP timesaccordingly.

Envirowise Advice Line 0800 585794 | www.envirowise.gov.uk

REDUCING WATER USE THROUGH CLEANING-IN-PLACE (CIP)

BATCH CHEMICALMANUFACTURER SAVESWITH CIP

A company manufacturing resin-based additives used a hotcaustic solution to cleanvessels, a process that tookseveral hours and resulted insignificant downtime. The useof high-pressure CIP systemsrealised cost savings of over£2 million/year from increasedproductivity and eliminated theneed for hazardous chemicals -a saving of over £20,000/year.Capital and installation costs of£182,000 resulted in a paybackof around one month. SeeEnvirowise case study CS273for further details.

IMPROVED CASKWASHING

A brewery redesigned the spraynozzle on the cask washer toimprove the spray action andensure better contact with thecask. This resulted in moreefficient use of water andreductions in steam use,maintenance requirements andvolume of effluent generated.Although the capital expenditurewas high, the payback wasaround 13 months.

CIP FINE TUNING PAYS OFF

A dairy reviewed its water use and identified CIP rinses as large users ofwater. An investigation found that the limits set on the conductivitymeter were too stringent. The rinse volumes were reduced withoutcompromising hygiene standards, achieving a water reduction of32,000 m3/year. In addition, operators now flush the vessels at the endof the day before CIP, reducing the solid waste load from 20% to 5-6%.

Where to save water

Concentrateddetergent

tank

Scavengepump

CIPdeliverypump

Disinfectant

Detergentpump

Interfaceprobe

Detergentstrengthprobe

Circulationpump

Heat exchanger

Lagging

Drain Drain Drain Drain

Levelprobes

To plant

From plant

Mains cold water

Pre-rinsetank

Dilutedetergent

tankPost-rinse

tank

• Have a schedule for emptyingand remaking the dilutedetergent, then experiment withextending it.

• All concentration probes mustbe cleaned and checkedregularly, particularly in hardwater areas.

Optimising post rinse

• Getting timings correct iscrucial to making efficient useof water.

TIP: Over-rinsing iscommon at this CIP stage:

check when the detergent hascleared, add a safety margin andset the rinse time accordingly.

Disinfectant rinse

• Discuss different types ofdisinfectant with your supplier.Some need less rinsing thanothers, and some can berecovered for re-use.

TIP: Consider chemicaldisinfection to replace

hot water or steam.

Final rinse

• Use just enough water to clearthe disinfectant, do not over-rinse.

TIP: Pressure fluctuationsmay compromise the

effectiveness of rinses directlyfrom the mains.

Changes to the equipment

Any changes to pipes, tanks,pumps, pressures, temperatures,plant configurations etc will affectthe efficiency and the water use ofCIP.

• Often the CIP times are simplylengthened.

• Pipework ‘dead legs’ may havebeen created.

• Turbulent flow may not beachieved.

• Spray heads may be under (orover) pressurised.

• Poor scavenging causes‘pooling’ in the equipment andpoor CIP.

Envirowise Advice Line 0800 585794 | www.envirowise.gov.uk

CUTTING FINAL RINSE TIME ACHIEVES REDUCTION INWATER USE BY CIP

When staff at a brewery examined the CIP cycle, they found that thefinal rinses used excessive amounts of water. The rinse time was cutfrom six bursts of six seconds each to six bursts of four seconds. Thissimple measure reduced water consumption in the final rinse from10,000 m3/month to 7,700 m3/month. This 23% reduction in wateruse saved the brewery £44,000/year.

Fig 1 Schematic of CIP system

Harwell | Didcot | Oxfordshire | OX11 0QJ | E advice@envirowise.gov.uk | www.envirowise.gov.uk

Envirowise - sustainable practices, sustainable profits. Envirowise is a Government-funded programme dedicated to putting the sustainable use of resources at the heart of business practice.It is managed by AEA Technology plc and Serco TTI. Envirowise is funded by Defra, the Scottish Government, the Welsh Assembly Government and Invest Northern Ireland.

© Crown copyright. First printed July 2008. Printed on paper containing 80% recycled post-consumer fibre.

This material may be freely reproduced in its original form except for sale or advertising purposes.

Soil - is the material present in theequipment, which CIP is trying toremove.

TIP: Dried or ‘baked on’soils need more CIP time,

so avoid this by cleaningimmediately after production.

Detergent - removes soil; usuallyalkaline (caustic) or acidic andused hot or cold.

Disinfectant (or sterilant) - killsmicro-organisms and reduces theirpopulation to a level which nolonger presents a hazard to healthand will not cause spoilage.

Sanitiser - removes soil and killsmicro-organisms (ie detergent anddisinfectant properties), and maybe used hot or cold.

TIP: Use a sanitiser if thecleaning task is not

difficult, to save CIP time andwater.

Interface - the area where onefluid mixes with another as it flowsthough a pipe.

Sprayball or sprayhead -distributes fluid within a vessel sothat it covers all the surfaces.

Line cleans - cleaning pipes byCIP; the cleaning fluid needs toreach a high enough velocity toachieve turbulent flow.

TIP: Get expert advice ifyou think flow is not

turbulent.

Pumps - delivery pumps sendfluid from the CIP set to theequipment and scavenge pumpsbring it back again.

TIP: Poor scavenging isvery common in CIP -

check to see if fluid is ‘pooling’in a vessel by holding theprogram and looking inside atvarious times.

Dead leg - a dead end in apipework system where flow canbecome stagnant, and bacteriacan build up.

Dilute detergent tank - holdsdetergent at a concentration readyfor use.

Full recovery CIP - circulatesdilute detergent and recovers asmuch as possible for use duringthe next clean.

Total loss CIP - operates byinjecting concentrated chemicalsinto mains water flow thencirculating around the equipment.All wastewater is discharged todrain.

TIP: If you have a totalloss CIP set, change it for

one with full recovery and askpotential suppliers how muchwater it will use.

TERMINOLOGY FURTHER INFORMATION

The Enhanced Capital Allowance(ECA) scheme1 enablesbusinesses to claim 100% firstyear capital allowances ininvestment in CIP equipmentnamed in the Water TechnologyList.

The following CIP equipment issupported:

• Monitoring and controlequipment

• Spray devices

Further information and advicecan be found at:

www.envirowise.gov.ukwww.eca-water.gov.uk

1 Developed by Defra and HM Revenue &Customs in partnership with Envirowise.

Envirowise publications:

EN660 Reducing water use incatering establishments

EN661 Reducing water use inlaundries

EN662 Understanding leaks,water pressure and meters

EN663 Reducing water use:showers

EN664 Reducing water use inwashrooms: taps

EN665 Understanding waterand wastewater bills

EN666 Reducing water use inwashrooms: urinals

EN667 Reducing water use inwashrooms: WCs

EN893 Product recovery -reducing water use andimproving resource efficiency

Prepared with assistance from Ashact, a Division of Hyder Consulting (UK) Limited.