Unit 15 Cleaning Chemicals Flashcards
What is the purpose of cleaning?
Is to permanently remove all the soil from the surfaces of the plant to leave it in a condition suitable for use.
What is the purpose of sterilising?
Is to kill any micro-organisms that remain on the internal surfaces of the plant after cleaning so the product is not contaminated. (mostly RTD’s)
What would you use if the same equipment was being used for strong flavoured products or brown or white spirits?
Liquor flush is all that’s used to clean the plant.
Give examples of products that require higher degrees of cleanliness.
Products that are sensitive to spoilage like beers, RTG’s and cream liqueurs.
What is the definition of sterilisation?
elimination of all forms of life including microbial spores, mostly achieved with live stream at a minimum of 120C and a contact time of at least 15 minutes.
What is the definition of hygiene conditions?
degree of cleanliness that eliminates all vegetative forms of life - mostly in liquid production and other beverage plants.
What is the definition of condition of clean conditions?
Suitable for the removal of all soils but not all vegetative cells.
What can growth control be affected by?
Limiting microbial growth by removal of nutrients or removal of protective materials
By removing all viable microbes by either total removal (sterilisation) or removal of vegetable cells only.
What cycle do control measures follow?
Decontamination (cleaning)
Disinfection to prevent growth or eliminate viable microbes.
Sterilisation to prevent the growth of any surviving organism in product, eliminating spoilage.
What are detergents?
Is a blend of chemicals which is put together to solubilise soil & remove it from the surface and ensure that it does not re deposit itself back onto the clean surface.
How do detergents help the cleaning process?
Penetrating the soil
Dissolving the soil
Dispensing the soil
Carrying the soil away
What is the purpose of sterilants?
they are formulated to kill microbes and bring micro organisms load to an acceptable level and work by:
Creating the conditions of temperature, pH, chemical or surface activity that can destroy micro organisms.
What is always used as the medium for carrying detergents?
Water & it has a high surface tension.
What do detergents contain to help surface tensions?
A substance that reduces surface tension which therefore increases the detergents wetting power.
What happens when a substance is dissolved?
It becomes chemically bound into the liquid and the liquid is usually clear.
If soil can be dissolved in the detergent liquid, not only can it be removed from plant surface, it can be carried away easily.
What are the 2 main types of soil that needs to be removed from the surface of a brewing and packaging plant?
Organic Soil = yeast protein, fat & sugar. Any detergent which will break it down is best to use.
Inorganic soil = scale and “stone”. Nitric acid or phosphoric acid is good for dissolving inorganic soil.
What happens if not all soil is soluble?
Insoluble soil can be removed if “dispersed” so it can be carried away in the liquid.
Detergents will contain substances which help to disperse the soil & hold is in suspension so it can be rinsed away.
What is important at completion of the cleaning cycle?
There is no detergent & accompanying soil remains on the plant surface.
It must be rinsed away.
What is detergents made of?
The base of acids and alkalis, therefore chemical properties are acidic or basic.
Alkaline detergents work better for what 2 reasons?
Organic soil tends to be more acidic in nature.
Basic detergents can hydrolyse organic polymer chains, which add to the easy removal of soil as smaller molecules,
What are the four ingredients for detergents?
- Base material (acid or alkalis)
- Surface active molecules as wetting agents
- Chelatting agents or sequestrants
- floccuating agents (sometimes)
Why are sequestrants or chelating agents added to detergents?
in order to soften water by grabbing metal ions like calcium or magnesium.
These metal ions bond dirt together.
Why are surface active molecules added to detergents?
Act as wetting agents that assist in the penetration of dirt.
Why are flocculating agents (sometimes) added to detergents?
to facilitate the easy removal of dirt by pulling dirt together in lumps - which is therefore easy to be removed.
What are Caustic detergents not suitable for?
Cleaning aluminium tanks
Whats the effects of caustic soda and what are some benefits/problems?
- Dissolves organic matter
-Sterilises especially when hot
Does not rinse well
Cannot be used by hand
dissolves aluminium
What are the effects of other alkalis and what are there benefits/problems?
Dissolves Organic Matter
Less Aggressive than Caustic soda.
very good dispersants
What are the effects of oxidants and what are the benefits/problems?
Helps dissolve protein
Sterilises
Very coorcive unless at a High pH
What are the effects of phosphates and what are the benefits/problems?
Soil removal
Very good rinsing properties.
What are the effects of acids and what is the benefits/problems?
dissolves scale
corrosive in high concentrations
not denatured by CO2
What are the effects of wetting agents and what are the benefits/problems?
reduces surface tension
may cause the detergent to foam.
what are the effects of sequestering agents and what are the benefits/problems?
prevent formation of scale
expensive
What are the 7 types of sterilant?
“halogens” like chlorine and iodine.
Formaldehyde
Ammonia
Hydrogen peroxide
peracetic acid
Ampholytic surfactants
What would you use to sterilise transfer mains, filter mains and packaging mains?
Hot water or steam
amphoteric surfactants
peracetic acid
What would you use to sterilise product vessels?
Amphoteric surfactants
peracetic acids
What would you use to sterilise filtration plant?
hot water or low pressure steam
amphoteric surfactants
peracetic acid
What would you use to sterilise the packaging plant?
hot water or steam
amphoteric surfactants
peracetic acids
How long and at what temp does heat need to be held for, to be effective?
90C for 15 minutes.
What what temperature and contact time will you achieve total sterilisation using steam?
120C for at least 15 mins.
But can be cleaned in 2-3 minutes for practicality purposes.
Describe high pressure cleaning.
combines high pressure, high temperature and detergent.
Reaches areas that are difficult to clean.
minimises detergent uses.
Describe foam cleaning
working solution is diluted with air.
small quantities of water is used.
foam is removed by rinsing with water.
describe cleaning in place
allows systems, vessels, piping, valves, and other equipment’s to be cleaned without dismantling all or part of the items.
