Assembly for and method of sampling particle-laden fluids and a cascade impactor used therewith
A description is given of an assembly for sampling particle-laden fluids for particulate content and particle size distribution; said assembly comprising: at least one cascade impactor adapted to be placed within a fluid stream to be sampled, said impactor including (I) a longitudinally extending tubular body having a fluid inlet at one end and a fluid outlet at the other end, and (II) a plurality of longitudinally spaced, successive particle collection stages located within said tubular body between said inlet and outlet and, together with said body, defining a fluid flow path from said inlet through successive particle collection stages to said outlet, said stages being constructed and positioned so as to cause successive drops in pressure between said stages as said stream of fluid moves along said path from said inlet to said outlet each of said collection stages including a gas jet plate fixedly located within and extending entirely across said tubular body and having a predetermined number of apertures of predetermined size extending therethrough, and an impactor plate fixedly located within said body adjacent to and downstream of said gas jet plate, said impactor plate including particle collection surface in confronting relationship with and a predetermined distance from said gas jet plate, each of said apertures in any given gas jet plate being designed to provide a ratio of the pressure at its upstream side as compared to the pressure at its downstream side, said ratio being selected below the critical pressure ratio of approximately 1.71 such that the gas stream flowing through said apertures does so at a rate which does not reach it critical flow rate above which the velocity of said fluid through said aperatures does not increase with a drop in pressure from said upstream side to said downstream side.
- Assignee:
- Electric Power Research Institute
- Patent Number(s):
- US 4211116
- OSTI ID:
- 5016971
- Resource Relation:
- Patent File Date: Filed date 21 Jun 1978
- Country of Publication:
- United States
- Language:
- English
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