Lesson 6 - Hygienic Design
In this lesson we will discuss the principles of hygienic design and how it is applicable in the brewing industry. Hygienic design covers equipment that is in contact with the product, as well as equipment and the environment that is not in contact with the product.
Vessels
Vessels need special consideration when it comes to hygienic design.
The following is important:
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Any structures inside the vessels should be accessible by the CIP system. Spray ball and shadow areas must either be avoided or catered for. Shadow areas are where equipment within a tank, for example, an agitator, prevents the liquid from a spray ball making full contact with all surfaces.
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Vessels need to drain completely, and all vessels should have a bottom outlet as shown in the figure below.
Figure: Hygienic design of vessels to facilitate draining
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Equipment mounted on vessels needs to be suitably isolated from the vessel through proper seals and shrouds. See the figure below.
Figure: Installation of an agitator motor above a tank
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All pipe lines into the tank must be designed to be cleanable as either part of the tank or part of the lines.
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Pressure relief valves and vacuum breakers need to be cleanable.
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Any sight glasses should be cleaned along with the tank.
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Utility or maintenance access holes should be raised.