Liquid level system

Claim 3

An apparatus as set forth in claim 1 wherein: each said sensors include a rigid housing enclosing said first movable barrier and providing therein said first and second chambers on the opposite sides of said first movable barrier; and said second movable barrier is mounted on the exterior of said housing.

Claim 4

An apparatus as set forth in claim 1 wherein: each said first and second movable barriers is a bellows.

Claim 5

An apparatus as set forth in claim 3 including: a fixed liquid displacing element extending into each of said bellows to minimize the liquid volume thereof.

Claim 6

An apparatus as set forth in claim 1 including: a vertical frame supporting said lower and upper sensors; and said conduit extends through said frame.

Claim 7

An apparatus as set forth in claim 1 wherein: both of said first and second liquids remain in liquid phase to a temperature of at least 650° F. even if pressure in the tank is lost.

Claim 8

An apparatus as set forth in claim 1 wherein: said first liquid is selected from the group consisting of sodium, potassium and NaK alloy.

Claim 9

An apparatus as set forth in claim 1 wherein: said first incompressible liquid is NaK.

Claim 10

An apparatus as set forth in claim 1 wherein: said second liquid is essentially inert.

Claim 11

An apparatus as set forth in claim 1 wherein: both of said first and second liquids are in solid phase at ambient temperature and in liquid phase at the operating temperature of the tank.

Claim 14

A liquid level system which may operate at a relatively high temperature and pressure comprising: (a) a tank having a relatively low liquid level and a relatively high liquid level; (b) lower and upper sensors mounted inside said tank adjacent to said relatively low liquid level and said relatively high liquid level, respectively; (c) each said sensor comprising: (1) first, second and third chambers; (2) a first movable pressure sensitive barrier separating said first and second chambers; (3) a fixed wall separating said second and third chambers; (4) said third chamber embodying a second movable pressure sensitive barrier exposed to the interior of the tank; (5) passageways providing flow communication between said second and third chambers; (d) a conduit providing flow communication between said first chambers of said lower and upper sensors; (e) a first liquid filling said first chambers and said conduit; (f) a second liquid different from said first liquid filling said second and third chambers of said lower and upper sensors; and (g) means connected to one of said second movable barriers for producing an electrical output signal proportional to the difference between the pressures at the respective locations of said second movable barriers, said difference being a function of the level of liquid in the tank.

Claim 15

A liquid level system which may operate at a relatively high temperature and pressure comprising: (a) a tank having a relatively low liquid level and a relatively high liquid level; (b) lower and upper sensors mounted inside said tank adjacent to said relatively low liquid level and said relatively high liquid level, respectively; (c) each said sensor comprising: (1) first, second and third chambers; (2) a first movable pressure sensitive barrier separating said first and second chambers; (3) a fixed wall separating said second and third chambers; (4) said third chamber embodying a second movable pressure sensitive barrier exposed to the interior of the tank; (5) passageways providing flow communication between said second and third chambers; (d) a conduit providing flow communication between said first chambers of said lower and upper sensors; (e) a first liquid filling said first chambers and said conduit; (f) a second liquid different from said first liquid filling said second and third chambers of said lower and upper sensors; and (g) means connected to one of said second movable barriers for producing an electrical output signal proportional to the difference between the pressures at the respective locations of said second movable barriers, said difference being a function of the level of liquid in the tank.

Claim 16

A liquid level system as set forth in claim 12 wherein: each said sensors includes a rigid housing enclosing said first movable barrier and providing said fixed wall.

Claim 17

A liquid level system as set forth in claim 12 wherein: each said first and second movable barriers is a bellows.

Claim 18

A liquid level system as set forth in claim 12 wherein: both of said first and second liquids are in solid phase at ambient temperature and are in liquid phase at said operating temperature even if pressure in the tank is lost.

Claim 19

A liquid level system as set forth in claim 12 wherein: said first liquid is highly reactive with water; and said second liquid is essentially inert.

Claim 20

A liquid level system as set forth in claim 16 wherein: both of said first and second liquids are metals.

Claim 23

An apparatus as set forth in claim 18 wherein: each said sensor includes a protective enclosure for said diaphragm; said protective enclosure including second pressure sensitive diaphragm adapted for exposure to the interior of the tank; a second liquid filling said enclosure and being essentially inert; and said first-mentioned liquid is highly reactive with water.