US 4,147,298 A · Fluid flow controller

Abstract

A fluid flow controller is disclosed particularly adapted for maintaining a variable value constant volume fluid flow through a conduit supplying fluid to a zone. A spring biased vane is disposed across the diameter of the conduit to provide a motion signal proportional to the average volume flow pressure across the diameter of the conduit. The motion signal from the vane and a transducer within a zone to which the fluid is being conducted responsive to an environmental parameter in the zone are connected to a controller assembly connected to control an actuator moving a damper within the conduit. The controller is adapted to position the damper to maintain the motion signal from the vane and the signal from the transducer within the controlled zone in balance. This is a continuation-in-part of application Ser. No. 711,066 filed Aug. 2, 1976, now abandoned.

Claims15

Dependent claims

In fluid delivery systems having a duct for directing fluid from a pressurized source into a space to be conditioned by the fluid including a movable damper within the duct for regulating the flow of fluid, motive means for positioning the damper, and a sensor in the space providing a first signal proportional to the state of the variable to be conditioned by the fluid, the improved controller for positioning the damper to provide fixed volumes of fluid flow through the duct comprising:

(a) means operably connected to the duct for providing a second signal proportional to the average across the diameter of the duct of the flow of fluid therethrough;
(b) adjustable means for providing a third signal proportional to a basic system offset;
and,
(c) summing means having said first, second, and third signals as inputs thereto and an output connected to drive the damper motive means for positioning the damper as a function of said first, second and third signals whereby the space is conditioned with the variable maintained at a preselected value.

1 more element

In fluid flow apparatus having a conduit for conducting flowing fluid, a movable damper disposed within the conduit for varying the cross-sectional area of the conduit, and an actuator connected to the damper for opening the damper to increase the cross-sectional area of the conduit and closing the damper to decrease the cross-sectional area of the conduit, apparatus for maintaining the volume of fluid flowing through the conduit constant comprising:

(a) a vane disposed across the diameter of the conduit adapted for movement from an at rest position in a first direction as a function of the average force across the diameter of the conduit of the fluid flowing therethrough;
(b) bias means connected to said vane for biasing said vane in a second direction opposite said first direction by a preselected amount of force whereby said vane is disposed in said at rest position when the average force of the flowing fluid across the diameter of the conduit on said vane is less than said bias force;
and,
(c) controller means having means for designating the desired flow volume through the conduit, means for sensing the position of said vane, and an output connected to the damper for opening the damper when the fluid flow is less than said desired flow volume and for closing the damper when the fluid flow is greater than said desired flow volume whereby the average flow volume across the diameter of the conduit of the fluid through the conduit is maintained equal to said desired flow volume.

1 more element

In a pneumatically operated damper controller for positioning a damper disposed to control the flow of fluid through a conduit having a pneumatic motor connected to position the damper as a function of the pressure within a pressurized pneumatic line connected to the pneumatic motor, the improved controller for maintaining the volume of fluid flowing through the conduit constant comprising:

(a) a bleed member connected into the pneumatic line connected to the pneumatic motor including a bleed orifice for bleeding fluid from the pneumatic line to reduce the pressure therein;
(b) a movable member including a seat adapted for movement between a first position wherein said orifice is closed by said seat and a second position wherein said orifice is open to its full bleed capacity;
(c) a first bias means connected to said movable member for biasing said movable member toward said first position;
(d) a second bias means connected to said movable member for biasing said movable member toward said second position, said second bias means being adapted to overcome said first bias means whereby said movable member is biased in said second position by a bias force equal to the difference between the bias forces of said first and second bias means;
and,
(e) a movable vane disposed within the conduit to respond to the pressure of fluid flowing therethrough, said vane being operably connected to said movable member to move said movable member toward said first position in response to increases in pressure of the fluid flowing through the conduit thereby positioning said seat relative to said orifice so that the fluid bleeding therefrom causes the pressure in the pneumatic line to the pneumatic motor to be an amount to position the damper to limit the flow of fluid through the conduit to an amount which puts the system in equilibrium whereby the constant flow volume of fluid flowing through the conduit is proportional to the difference between said first and second bias forces.

3 more elements

Dependencies are inferred from the claim text.

Fluid flow controller

Life of this patent

Fluid flow controller

Life of this patent

Abstract

Claims15