Introductions
Water is the major raw materials used in production of alcoholic and non alcoholic beverages as such the supply
and treatment of water is a vital
importance to the brewery because the availability of water affects the quality of product.
Raw Water
Supply
The raw water is sourced
form 5
boreholes. The depth of each boreholes is 120m. each pump is connected to the surface with that
flexible riser pipe.
From the borehole analysis,
it was detected that it contains some ions from dissolved salts.
These ions are undesirable for brewing eg
irons, this has an influence on the
flavour and their color of the
beer, it inhibits saccharification and given
a hard bitterness. it supports the oxidation of beer ingredient which leads to hazy beer. Manganese at higher
levels has the same effect as the iron is beer. It also has a negative
influence of foam stability. Also ammonium in raw water is an
indicator for organic contamination and
bears the risk of forming nitrate through partial oxidation reaction. Nitrate
is toxic for yeast as it inhibits its growth and fermentation.
Furthermore, the water is aggressive due to lack of
calcium (CA) when compared to the
carbonate content. As such, these ions/impurities that have adverse effects on
beer production need to be removed as
well as the addition of Ca(OH)2
lime to meet the calcium specifications. This
is basically what is being done in water treatment plant. These plant is designed for the production of two
main water namely; I soft (service) water ii product water
Lime Preparation
Tank
Lime milk preparation is
carried out manually in the preparation
tank here, the white lime is mixed with water to form a
solution, this mixture is stirred with a
stirrer. After through mixing, the lime
milk will be delivered into the lime saturator by the help of a
pump.
Lime Saturator
The lime milk is pumped into
the lime saturator as well as the raw
water. Here the water is saturated with
Ca(OH)2 ie increases the calcium hardness
of the water. Also this lime
dosing is used to regulated the PH
Oxidation Air Feeding
The water is
aerated as at flows from the lime saturator to the sand filter. This air
oxidizes some impurities in the water such as iron and manganese. Once oxidized, these chemicals fall out of the
solution and become suspended in the water.
The suspended material is then
removed through sand filtration processes.
Sand Filters
The sand filter are 3
in number these are enclosed tanks that
contain different aggregates of gravel
arranged in different layers.
During filtration, water flows form the
top through the filter medium (Gravel)
to the bottom of the filter . On
the process, the layers of the gravel will trap the suspended material both
the iron and manganese from the water
while the water passes through pipe to carbon filter . The next stage.
After
filtration, the filter ate will be split
up onto two parallel treatment system in order to obtain
softened water and product
water.
Softened (Service) Water
To produce water,
50% of the pre-treated water is sorted in the storage tank, on the
on-line to the softened water storage
tank, chlorine dioxide is dosed as disinfectants additive in the return linking line of
the soft water distribution
pumps to obtain a free chlorine level of 0.5mg/l at the point of use.
Use of the soft
water in the company
v it is used as rise water for tanks and beer lines
v it is use in
the washing of the crates and
bottles and also in pasteurization of
the packaged product
v it is used as
the general purpose water in the brewery
Product Water
For production of product water, the remaining 50% of
the pre-treated water will flow through
two carbon filters. At the carbon filter, the colour, odour and taste
are removed from the pretreated water. Then the water flows form
the carbon filter to the product storage tank where it is stored
until when it is needed for distribution.
UV Unit
Before entering the distribution
system form the product water storage tank, the product water will pass an
ultra –violet (UV) unit for disinfection purpose by minimizing the
microbiological load. The (UV) destroys
micro organisms by changing their genetic information. The (UV)unit
is installed after the distribution
pumps that distribute the water to the brewery. This arrangement is so because
the product water needed not to stay long after passing through (UV) unit. A if it does, micro-organisms will start to
grow in it prior to its usage.