Exam Question
With reference to Vacuum Sewage System
(a) Sketch & Describe a Vacuum Sewage System. (7)
(b) State the advantages of Vacuum Sewage System. (5)
(c) State the different causes of dropping vacuum. (4)
Class 2 (2nd Engineer)
MEKG
📅 Apr 2024
Reference Answer
### (a) Description and Sketch of a Vacuum Sewage System
**Principle of Operation:**
A vacuum sewage system utilizes a pressure differential to transport sewage (black water) from toilets and urinals to a central collection unit. Unlike traditional gravity-based systems, it does not rely on water head and downward sloping pipes. A vacuum of approximately -0.5 to -0.7 bar gauge is maintained in the piping network and a central collection tank. When a toilet is flushed, its discharge valve opens momentarily, allowing the higher atmospheric pressure in the compartment to push the bowl's contents into the vacuum piping, followed by a plug of air which scours the pipe clean.
**Key Components and Operation Cycle:**
**Principle of Operation:**
A vacuum sewage system utilizes a pressure differential to transport sewage (black water) from toilets and urinals to a central collection unit. Unlike traditional gravity-based systems, it does not rely on water head and downward sloping pipes. A vacuum of approximately -0.5 to -0.7 bar gauge is maintained in the piping network and a central collection tank. When a toilet is flushed, its discharge valve opens momentarily, allowing the higher atmospheric pressure in the compartment to push the bowl's contents into the vacuum piping, followed by a plug of air which scours the pipe clean.
**Key Components and Operation Cycle:**
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