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US 4,790,650 AGranted
Condensation nucleus counter
AssigneeTSI Incorporated
InventorPatricia B. Keady
Life of this patent
Estimating the term…
Abstract
A condensation nucleus counter (1) for measuring particulate concentration within a gaseous environment, including an inlet orifice (3) leading to a flow path (5) within saturator (4). The resultant vapor (10) enters a condenser section (11) wherein the particulate matter suspended within serves as the nucleus for condensation. The enlarged droplets (23) thus formed enter a conventional optical particle counter section (15).
Claims13
A thermal-diffusional continuous-flow condensation nucleus counter comprising:
- (a) a reservoir;
- (b) a saturator block, the saturator block residing within the reservoir, the saturator block being formed of a porous, electrically conductive material such that a static electric charge cannot be accumulated in regions in fluid communication with the reservoir;
- (c) a liquid, the liquid being housed within the reservoir, the liquid thereby permeating throughout the saturator block;
- (d) a sample gas stream, the sample gas stream being in fluid communication with the reservoir, the reservoir having a volume substantially filled by the saturator block, the sample gas thereby entraining the vapor from the saturator block;
- (e) a cooling condenser, the condenser substantially surrounding the sample gas stream as the sample gas exits the reservoir, the condenser serving to cool the sample gas stream such that the entrained vapor condenses on any particulate matter residing within the sample gas stream so as to form droplets relatively larger than the particulate matter;
- and
- (f) indicating means, the indicating means encountering the sample gas stream as the sample gas stream exits the cooling condenser, the indicating means serving to count and identify the number of droplets formed within the sample gas stream.
4 more elements
A method of measuring particulate matter concentration within sample gas streams, comprising the steps of:
- (a) saturating a block formed from a porous material with a volatile liquid;
- (b) introducing the sample gas stream through a slotted cross section flow passage, the flow passage being in fluid communication with the saturator block such that the liquid may readily evaporate within the sample gas stream;
- (c) routing the resultant sample gas stream through a condenser section, the condenser section being formed from a plurality of air flow passages, the flow passages being configured as a front flow passage and a rear flow passage, each flow passage being equally angularly displaced about a perpendicular plane such that particulate matter within the gas stream will serve as a nucleus for condensation, thereby forming a droplet corresponding to each discrete particle;
- (d) passing the resultant sample gas stream through an optical counter in order that the droplets may be identified and counted;
- and
- (f) heating the sample gas stream exiting from the optical counter so as to cause the evaporation of the droplets, thereby preventing the counting of a particular droplet more than once.
3 more elements
Dependencies are inferred from the claim text.