GB1417283A - Plant for the accurate maintenance of slight underpressure in container systems connected to a gas suction plant - Google Patents

Abstract

1417283 Valves LICENTIA PATENTVERWALTUNGS GmbH 13 July 1973 [21 July 1972] 33542/73 Heading F2V Apparatus for maintaining a slight underpressure in containers 1, 2, e.g. in nuclear reactor or chemical technology, comprises first and second liquid receptacles 11, 12 communicating beneath the liquid, liquid supply line 9, liquid overflow lines 7, 8 connected to the receptacles at different levels, a compensating conduit 13, and a suction line 5 having its inlet end located between said levels. The supply line 9 contains a valve 8 controlled in accordance with the liquid levels at points 14, 15. In nuclear reactor technology the apparatus is used to maintain a slight underpressure of air used for decay of short-lived isotopes present in the containers 1, 2. The system is shown in a stable situation with the desired underpressure present in receptacle 12 and containers 1, 2. If liquid is fed into the containers 1, 2, the pressure increases and causes the liquid level in receptacle 12 to fall and uncover the lower end of suction line 5 whereby the displaced air is drawn off. If liquid is discharged from the containers 1, 2, the consequent pressure drop causes the liquid in receptacle 12 to rise and overflow at 15, and the liquid level in receptacle 11 to fall and uncover the associated end of conduit 13 so that makeup air can flow from line 6 through conduit 13 and receptacle 12 into the containers 1, 2. If the plant creating the suction should fail, the consequent rise in pressure causes liquid to overflow at 7. Thus if liquid is fed into the containers 1, 2 no dangerous overpressure can develop since liquid merely continues to overflow at 7 until the end of conduit 13 in receptacle 12 is uncovered to permit relief of excess pressure through conduit 13 and line 6.