Dilution tunnel
AssigneeCaterpillar Inc.
InventorRussell Graze
Life of this patent
Estimating the term…
Abstract
A dilution tunnel having a flow chamber structure with an inlet, an outlet, and an internal flow passage for a sample gas, the sample gas being adapted to flow in a flow direction between the inlet and the outlet. The flow chamber structure having a plurality of pores that communicate between an outside region external of the flow chamber structure and the internal flow passage. The pores are adapted to introduce a diluting gas from the outside region into the internal flow passage. The flow chamber structure is adapted to provide a diluting rate of the dilution tunnel that varies in the flow direction of the dilution tunnel.
Claims22
-8. (canceled)
A dilution tunnel, comprising:
- a porous tube having an inlet and an outlet and a flow axis passing through said porous tube, the inlet, and the outlet, said porous tube defining an internal flow passage for a sample gas between the inlet and the outlet, the flow axis defining an axial flow direction of the sample gas through said porous tube;
- said porous tube having a plurality of pores that communicate between an outside region external of said porous tube and the internal flow passage, said pores being adapted to introduce a diluting gas from the outside region into the internal flow passage;
- and
- wherein a porosity of said porous tube varies in at least one of the axial flow direction and a radial direction that extends radially outward from the flow axis.
-19. (canceled)
A gas sampling system for analyzing a first gas, comprising:
- a dilution tunnel;
- and
- a second gas source that supplies a second gas;
- wherein said dilution tunnel includes a porous tube having an inlet and an outlet and a flow axis passing through said porous tube, the inlet, and the outlet;
- said porous tube defining an internal flow passage for said first gas between the inlet and the outlet, the flow axis defining an axial flow direction of said first gas through said porous tube;
- said porous tube having a plurality of pores that communicate between an outside region external of said porous tube and the internal flow passage, said pores being adapted to introduce said second gas into the internal flow passage;
- and
- wherein a porosity of said porous tube varies in at least one of the axial flow direction and a radial direction that extends radially outward from the flow axis.
A method of diluting a first gas with a second gas, comprising the steps of:
- passing a first gas through a first region in a flow direction along a flow axis of the first region;
- passing a second gas through a second region, the first and second regions being separated by a porous structure;
- and
- introducing the second gas into the first region at a variable rate, determined by the porous structure, that changes in the flow direction of the first gas.
A method of manufacturing a dilution tunnel, comprising the steps of:
- providing a plurality of porous tubes, each porous tube having a different diluting rate defined by at least one of the porous tube's geometry and porosity;
- cutting respective sections from each porous tube;
- and
- serially coupling the respective sections to each other to form an a single porous tube that defines an internal flow passage.
Dependencies are inferred from the claim text.