Siphon breaker

The high-point vent in arrangements 6, c, e in Fig 5.1 vents inerts and serves as a siphon breaker. When the reflux piping downstream of the vent is large enough to permit vapor upflow simultaneous with liquid downflow, arrangements 6 and c become equivalent to arrangement d. A well-sized restriction orifice on the vent will minimize vapor upflow. 

Fig. 19.5 Large outdoor fermentation vessel (USP 3, 374, 726). 1. Tank 2. Cooling jacket 3. Foamed-synthetic resin 4. Manhole 5. Beer drainage cock 6. Beer feed pipe 7. Beer discharge pipe (pivoted) 8. Exhaust pipe 9. Siphon breaker 10. Pressure relief valve 11. Vacuum breaker 12. Thermometer and liquid depth senser 13. Water and detergent supply pipe 14. Water and detergent spray.

The cold 1 piping enters the reactor vessel at the same level as the hot leg nozzles, and the 260°C return flow is directed downwards to the reactor core inlet via the down- comer. On its way down, the flow velocity is increased in a siphon breaker arrangement with open connections to the pressurizer. The siphon breaker is intended to prevent siphoning ofT too much reactor pool water inventory in the hypothetical event of a cold leg rupture. During normal operation, the siphon breaker does not affect the water circulation. At the bottom of the annular downcomer the return flow enters the reactor core inlet plenum. 

Density locks (thermal barriers), siphon breakers, and wet thermal insulation Prestressed concrete reactor vessel Long-term passive residual heat removal system Reactivity control without control rods... 

Coolant mventoiy Water losses liimted by siphon breaker function nmaiy side) passive Condensation pool water can be replenished from outside, reactor pool water also... 

Reactor Closure j/Floor Slab Cavity Cooling Channels Cavity Liner Cavity Cooling Baffle Coolant Pumps Siphon Breakers Control Rod Drives Guard Vessel Reactor Vessel Graphite Liner Outer Reflector Reactor Core Inner Reflector... 

Code required prevention of flow from any connected system back into the city water system essentially a siphon breaker actuated if city water pressure is lower than pool water pressure. 

In the current pre-conceptual design, the AHTR has an annular core through which the coolant flows downward. The liquid salt coolant flows upward through the non-fiiel graphite section in the middle of the reactor. The coolant pumps and their intakes are located above the reactor core with appropriate siphon breakers thus, the reactor cannot lose its coolant except by failure of the primary vessel. The guard vessel is sized so that even if the primary vessel fails, the core remains covered with salt. 

Accidents have also occurred while NG was being transported around manufacturing facilities via gravity flow in gutters. To increase the safety of such transport, detonation breakers can be introduced along its flow path. An example of a detonation breaker is shown in Fig 29 which consists of a lead tank half-filled with water. NG flows into the tank, collects on the bottom and runs on from below thru the siphon. This arrangement interrupts the NG stream. Detonation cannot be transferred readily thru the water barrier... 

Some systems introduce the supply below the flood level of water in the receiver. Such a system should include a vacuum breaker mounted above the receiver to prevent siphoning back into the potable water supply. 

---