Movable venturi type tube flow meter

Claim 2

A flow meter comprising a Venturi tube having opposite ends of different cross sections and being mounted movable in an axial direction along a horizontal axis; first fixed means for supplying flowing liquid at one end and second fixed means for receiving the liquid after it has flowed through said Venturi tube at the other end thereof; first resilient means connecting said first fixed means to said one end of said Venturi tube and second resilient means connecting said other end to said second fixed means to bias said Venturi tube to a neutral position in tHe absence of flow of liquid; first actuating means connected to said Venturi tube and actuated by and proportionately to movement of the same in said axial direction during flow of said liquid therethrough; second actuating means actuated by the pressure of said liquid at said inlet and the pressure at said outlet end of said Venturi tube; and means for determining the actual flow of liquid through said Venturi tube, said last-mentioned means being responsive to said first and second actuating means.

Claim 3

A flow meter as defined in claim 1, wherein said first fixed means for supplying liquid at one end and said second fixed means for receiving the liquid at the other end of said Venturi tube comprise a pair of stationary tubes aligned with and respectively arranged axially spaced from said opposite ends of said Venturi tube.

Claim 4

A flow meter as defined in claim 2, wherein said first actuating means comprises a magnetic core connected to said Venturi tube for movement therewith in axial direction and a stationary coil surrounding said core.

Claim 5

A flow meter as defined in claim 3, wherein said resilient means comprise a pair of bellows respectively forming a pair of chambers about said opposite open ends of said Venturi tube and the adjacent ends of said stationary tubes, and wherein said second actuating means comprise pressure difference gauge means including diaphragm means and passage means leading from said chambers to opposite sides of said diaphragm means so as to deflect the latter in dependence on the difference of the pressure of the liquid at said opposite ends of said Venturi tube.

Claim 6

A flow meter as defined in claim 4, wherein said means for determining actual flow of liquid through said Venturi tube comprise a pair of transducer means connected to said diaphragm means and said stationary coil, respectively, and computer means connected to said transducer means.

Claim 7

A flow meter as defined in claim 4, and including a fluid-tight housing surrounding said Venturi tube and said bellows connected thereto, means connected to said first actuating means for regulating the pressure in said housing so as to maintain said Venturi tube in said neutral position, said second actuating means comprising a pair of pressure difference gauge means, each including a diaphragm, and passage means for transmitting the fluid pressure in one of said chambers and that in the interior of said housing respectively to opposite sides of one of said diaphragms and the fluid pressure in the other of said chambers and that in the interior of said housing respectively to opposite sides of the other said diaphragms.

Claim 8

A flow meter as defined in claim 6, wherein said means for determining actual flow of liquid through said Venturi tube comprises a pair of transducer means respectively connected to the diaphragms of said pair of pressure difference gauge means and computer means connected to said transducer means.

Claim 9

A flow meter as defined in claim 6, and including radially outwardly extending pressure receiving members fixed to and surrounding said open ends of said Venturi tube, said pair of bellows being respectively fixed to the outer peripheries of said pressure receiving members so that one side of each pressure receiving member is subjected to the pressure of the liquid in the respective chamber and the other side to the pressure of the liquid in said housing.

Claim 10

A flow meter as defined in claim 4 and including radially outwardly extending pressure receiving members fixed to and surrounding said open ends of said Venturi tube, said pair of bellows being respectively fixed to the outer peripheries of said pressure receiving members so that the latter are subjected to the pressure of the liquid in said chambers.

Claim 11

A flow meter as defined in claim 9, wherein said radially outwardly extending pressure receiving members are annular members having equal outer diameters.

Claim 12

A flow meter as defined in claim 3, wherein said resilient meAns comprises a bellows forming a chamber about one of said opposite open ends of the Venturi tube and the adjacent end of the corresponding one of said stationary tube so as to form a chamber about said adjacent ends, and spring means between the other end of said Venturi tube and the adjacent end of the other of said stationary tubes, and including a fluid-tight housing surrounding said Venturi tubes and said resilient means, said spring means being arranged so that the space between said other end of said Venturi tube and said adjacent end of the other stationary tube communicates with the interior of said housing whereby the latter will be filled with liquid passing through the Venturi tube, and the liquid in the housing will be maintained at a pressure equal to the pressure at said other end of said Venturi tube, said second actuating means comprising difference gauge means including a diaphragm and passage means for transmitting the pressure of the liquid in said chamber and in the interior of said housing respectively to opposite sides of said diaphragm.

Claim 13

A flow meter as defined in claim 11, wherein said means for detecting actual flow of liquid through said Venturi tube comprises a pair of transducer means respectively connected to said diaphragm and said coil, and computer means connected to said transducer means.

Claim 14

A flow meter as defined in claim 3, and including radially outwardly extending pressure receiving members fixed to and surrounding said open ends of said Venturi tube, said resilient means comprise a pair of bellows respectively connected to the outer peripheries of said pressure receiving members and forming a pair of chambers about said opposite ends of said Venturi tube and the adjacent ends of said stationary tubes, and wherein said second actuating means comprise a pair of additional bellow means each including a movable plate and a stationary plate, and a pair of passage means respectively providing communication between the interior of said pair of chambers and the interior of said pair of additional bellows, the movable plates of said pair of additional bellows being respectively fixed to said pressure receiving members and having respectively effective pressure receiving areas equal to that of said members.

Claim 15

A flow meter as defined in claim 13, wherein said means for detecting actual flow of liquid through said Venturi tube comprises transducer means connected to said stationary coil and flow indicator means connected to said transducer means.