Positive displacement piston flow meter with damping assembly
First Claim
1. A positive displacement piston flow meter comprising:
- (a) a hollow flowtube having two opposite open ends;
(b) a piston disposed in said flowtube for movement between a first position relative to one of said open ends and a second position relative to the opposite open end thereof;
(c) means for connecting said flowtube to an external pump for directing a gaseous fluid through said flow meter at a flow rate to be measured by said flow meter;
(d) valve means for controllably reversing the direction of movement of said piston in said flowtube between said first and second position respectively; and
(e) damping means for damping pulsations in gas flow through said flowtube, said damping means comprising at least one nonporous elastic diaphragm responsive to pressure pulsations in said flowtube and a porous member adjacent thereto with the porous member having a multiplicity of voids and a plurality of open channels extending to the elastic diaphragm and distributed throughout the porous member.
2 Assignments
0 Petitions
Accused Products
Abstract
A piston flow meter for measuring the flow of a gaseous fluid, such as ambient air, through the flow meter by timing the displacement of a piston in a hollow precision bore flowtube over a fixed distance. The piston is reciprocated from opposite ends of the flowtube by a poppet valve which controls the direction of movement of the piston in the flowtube. Ambient air is drawn into the flow tube from the atmosphere by an external pump connected to an inlet at one end of the flowtube. The flow meter includes a damping assembly for damping pulsations in gas flow through said flowtube with the damping assembly preferably located adjacent the pump inlet to the external pump. The damping assembly comprises damping means which includes a porous member and at least one elastic diaphragm contiguous thereto with the porous member having a multiplicity of voids and a plurality of open channels extending through the porous member to the elastic diaphragm.
729 Citations
13 Claims
-
1. A positive displacement piston flow meter comprising:
-
(a) a hollow flowtube having two opposite open ends; (b) a piston disposed in said flowtube for movement between a first position relative to one of said open ends and a second position relative to the opposite open end thereof; (c) means for connecting said flowtube to an external pump for directing a gaseous fluid through said flow meter at a flow rate to be measured by said flow meter; (d) valve means for controllably reversing the direction of movement of said piston in said flowtube between said first and second position respectively; and (e) damping means for damping pulsations in gas flow through said flowtube, said damping means comprising at least one nonporous elastic diaphragm responsive to pressure pulsations in said flowtube and a porous member adjacent thereto with the porous member having a multiplicity of voids and a plurality of open channels extending to the elastic diaphragm and distributed throughout the porous member. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
Specification