Isokinetic sampling system

Claim 2

An isokinetic sampling system for measuring the amount of contaminant carried per unit volume of fluid flowing through a fluid conduit including: fluid flow velocity equalizer means arranged in said conduit for producing substantially equal fluid flow velocities over the cross-sectional area of said conduit, a fluid flow measuring station having a plurality of sensors aligned in a sensing plane, said station being positioned in said conduit immediately adjacent to and downstream of said fluid flow velocity equalizer means for sensing fluid flow velocity and flow rate through said conduit, isokinetic sampling means positioned in said duct near said sensing plane and having a plurality of inlets distributed over the cross-sectional area of said conduit for receiving a sample of fluid and contaminant flowing through said conduit, sample sensing means for sensing the velocity of said sample flowing into said isokinetic sampling means, and control means responsive to the fluid flow velocity sensed by said measuring station and to the sample flow velocity for regulating the sample flow velocity relative to said fluid flow velocity.

Claim 3

The system of claim 1 wherein said fluid flow velocity equalizer means comprises a first honeycomb section which completely fills the cross-section of said conduit and has a plurality of parallel, axially extending passages, the lengths of said passages varying over the cross-sectional area of said conduit to equalize the fluid flow velocities across the cross-sectional area of said conduit.

Claim 4

The system of claim 2 wherein said fluid flow velocity equalizer means further comprises: a second honeycomb section in said conduit upstream of said first honeycomb section having axially extending passageways of larger cross-sectional area than said passageways in said first honeycomb section for suppressing the fluid flow velocities near the center of said conduit relative to the fluid flow velocities near the walls of said conduit.

Claim 5

The system of claim 3 wherein said fluid flow velocity equalizer means further comprises a third honeycomb section in said conduit upstream of said second honeycomb section having axially extending passageways of larger cross-sectional area than said passageways in saId second honeycomb section for converting turbulent flow in said conduit to laminar flow.

Claim 6

The system of claim 1 wherein said plurality of inlets lie in said sensing plane.

Claim 7

The system of claim 5 further comprising manifold means for communicating said inlets together at a point near the center of said conduit, the cross-sectional area of said manifold means increasing from the walls of said conduit to the center thereof to facilitate isokinetic flow of said sample through said manifold means.

Claim 8

The system of claim 1 wherein said sample sensing means comprises a cylindrical chamber of known cross-sectional area, a fourth honeycomb section in said chamber for creating laminar flow of said sample, and a sensing tip in said chamber downstream of said fourth honeycomb section for measuring the static and total pressures of said sample.

Claim 9

The system of claim 1 further comprising manifold means for communicating said inlets together, outlet means connected to said manifold means for carrying said sample from said conduit, and filter means in said outlet means for collecting said contaminant from said sample.

Claim 10

The system of claim 8 wherein said sample sensing means is downstream of said filter means and said control means comprises a valve for varying the flow of said sample through said sample sensing means to equalize flow velocities of said fluid and said sample, and a vacuum pump downstream of said sample sensing means for pumping said sample out of said conduit.

Claim 11

The system of claim 1 further comprising an outlet line through which said sample flows, an analyzer in said outlet line for identifying said contaminant and measuring the quantity of said contaminant, said sample sensing means positioned in said outlet line downstream of said analyzer, and wherein said control means comprises a comparator for comparing the flow velocities of said fluid and said sample, a control valve in said outlet line downstream of said sample sensing means for restricting or increasing the flow of said sample through said outlet line in response to the output of said comparator, and a vacuum pump in said outlet line downstream of said sample sensing means for pumping said sample through said outlet line.

Claim 12

The system of claim 10 further comprising a second sample sensing means in said outlet line immediately downstream of said analyzer for measuring the volume of said sample passing through said analyzer, an outlet bypass line connected to said outlet line and bypassing said analyzer and said second sample sensing means, and bypass control means for regulating the flow of said sample through said bypass line to maintain a constant flow rate of sample through said analyzer.

Claim 13

The system of claim 11 wherein said bypass control means comprises a bypass control valve in said outlet line immediately downstream of said second sample sensing means receiving the sample flowing through said bypass line and a bypass regulator which monitors said second sample sensing means and operates said bypass control valve to maintain a constant sample flow rate through said analyzer.

Claim 14

An isokinetic sampling system for measuring the amount of contaminant carried per unit volume of fluid flowing through a fluid conduit including fluid flow velocity equalizer means arranged in said conduit for producing substantially equal fluid flow velocities over the cross-sectional area of said conduit, a fluid flow measuring station having a plurality of sensors aligned in a sensing plane, said station being positioned in said conduit iMmediately adjacent to and downstream of said fluid flow velocity equalizer means for sensing fluid flow velocity and flow rate through said conduit, conduit flow control means responsive to the flow velocity sensed by said station for maintaining a constant flow rate of said fluid through said conduit, isokinetic sampling means positioned in said conduit near said sensing plane and having a plurality of inlets distributed over the cross-sectional area of said conduit for receiving a sample of fluid and contaminant flowing through said conduit, an outlet line carrying said sample away from said conduit, a valve in said outlet line for setting the sample flow velocity at the same magnitude as the velocity of said fluid flowing through said conduit, and pump means in said outlet line for pumping said sample out of said conduit and through said outlet line.

Claim 15

An isokinetic sampling system for measuring the amount of contaminant carried per unit volume of fluid flowing through a fluid conduit including fluid flow velocity equalizer means arranged in said conduit for producing substantially equal fluid flow velocities over the cross-sectional area of said conduit, a fluid flow measuring station having a plurality of sensors aligned in a sensing plane, said station being positioned in said conduit iMmediately adjacent to and downstream of said fluid flow velocity equalizer means for sensing fluid flow velocity and flow rate through said conduit, conduit flow control means responsive to the flow velocity sensed by said station for maintaining a constant flow rate of said fluid through said conduit, isokinetic sampling means positioned in said conduit near said sensing plane and having a plurality of inlets distributed over the cross-sectional area of said conduit for receiving a sample of fluid and contaminant flowing through said conduit, an outlet line carrying said sample away from said conduit, a valve in said outlet line for setting the sample flow velocity at the same magnitude as the velocity of said fluid flowing through said conduit, and pump means in said outlet line for pumping said sample out of said conduit and through said outlet line.

Claim 16

The system of claim 13 further comprising: a filter in said outlet line for collecting said contaminant, and integrating means responsive to said station for measuring the total volume of fluid flowing through said conduit during the operation of the sampling system.

Claim 17

The system of claim 14 further comprising a sample sensing means in said outlet line for measuring sample flow velocity, and control means responsive to the fluid flow velocity sensed by said measuring station and to the sample flow velocity for regulating sample flow velocity relative to said fluid flow velocity.