Plate Heat Exchangers (PHE) Flashcards
(18 cards)
What is the typical temperature range of wort ex-clarification?
96-98°C
What is the desired exit temperature range for cooled wort?
6-20°C
What relationship is engineered in a plate heat exchanger?
The size of the heat exchange (number of plates) and the desired exit temperature of cooled wort
How much chilled water is typically used to cool 100 hL of wort at 97°C to 16°C?
Approximately 110 hL of chilled water at 10°C
What factors need to be known to decrease wort temperature?
- Temperature of the hot wort
- Temperature of the cooling medium
- Desired exit temperature of cold wort
- Flow rates of hot wort and cooling medium
What can be done to achieve a lower exit temperature from a plate heat exchanger?
- Increase the number of plates
- Slow the flow rate
- Change the refrigerant
- Introduce a second stage refrigerant
What is the flow direction of the two media in a plate heat exchanger?
Counter current flow
What is the typical volume ratio of hot water generated to wort cooled?
1.1 : 1.0
What type of surface do heat exchanger plates have?
Raised (embossed) surface, typically in a chevron style
Why is water typically used as a cooling medium in breweries?
To recover and reuse energy locked within hot wort
What is the consequence of using ambient water instead of chilled water?
Cooling would take longer or require massive heat exchangers
What is the key benefit of using chilled water in the brewing process?
The ability to create hot water for brewing
What must be ensured about the quality of chilled water used?
It must be brewing (product) quality water
What are the advantages of plate heat exchangers?
- Improved efficiency
- Compact size and versatility
- Inspectability
- Ease of maintenance
- Low cost of maintenance and replacement
- Cleanability using reverse flow
What cleaning regime is often used for plate heat exchangers?
Caustic soda (NaOH) cleaning regime
What must be regularly inspected and maintained in plate heat exchangers?
Gaskets
What is the purpose of the centralized cleaning in place system (CIP)?
To effectively clean and remove organic deposits and scale
True or False: Plate heat exchangers have moving parts.
False
