ATMOSPHERIC MONITOR BY MEANS OF CHEMILUMINESCENT REACTION

• US 3,710,107 A
• Filed: 01/25/1971
• Issued: 01/09/1973
• Est. Priority Date: 01/25/1971
• Status: Expired due to Term

• Current Assignee: Gary J. Warren, Gordon L. Babcock
• Original Assignee: Gary J. Warren, Gordon L. Babcock
• Inventors: Warren, Gary J., Babcock, Gordon L.
• Primary Examiner(s): Borchelt, Archie R.
• Application Number:
  US05/109,202
• Time in Patent Office: 715 Days
• Field of Search: 250/71R,71.5R,83.3IR,435R,218 128/1 351/96,51,97 23/230,257 350/3
• US Class Current: 436/135
• CPC Class Codes: G01N 21/766 of gases
• CPC Class Codes: Y10T 436/206664 Ozone or peroxide

Abstract

A continuous, gas phase chemiluminescent monitor is disclosed. Air is introduced into a reaction chamber through an elongated nozzle. A chemiluminescent reagent gas such as ethylene for detecting ozone or ozone for detecting nitrogen oxides is injected into an annular inlet surrounding the air nozzle. The gases mix within a mixing chamber at the end of the concentric nozzle and form a turbulent flowing mixture which exits through the orifice of the nozzle and reacts within the reaction chamber. A light detector such as a photomultiplier tube is disposed adjacent the chamber and the chemiluminescent output of the reaction is detected and the signal is amplified and recorded, preferably as a digital readout. The flow rate of reagent gas is controlled at the inlet while the flow rate of air is controlled by means of a vacuum pump attached to the outlet of the reaction chamber, preferably by a pump incorporating an electronically driven diaphragm.

Claims

2. A monitor according to claim 1 in which said electro-optical means includes a photomultiplier tube.

3. A monitor according to claim 1 in which said withdrawal pump means includes a pump chamber and electronic oscillating means for driving said pump chamber.

4. A monitor according to claim 3 in which said oscillating means comprises a diaphragm and a solenoid for oscillating said diaphragm.

5. A monitor according to claim 3 in which said flow control means includes electrical frequency control means connected to said oscillating means for controlling the frequency thereof.

6. A monitor according to claim 1 in which said first and second inlet means comprise a set of concentric elongated tubes and said mixing head is formed by the extension of the outer tube past the end of the inner tube to form an enclosed mixing chamber and outlet orifice.

7. A monitor according to claim 1 in which said reaction chamber is formed of a plurality of separable parts and a gas-tight joint for joining said parts.

8. A method of determining the quantity of ozone in the atmosphere comprising the steps of:

continuously flowing a controlled supply of ethylene to a closed mixing head having an outlet orifice communicating with a reaction chamber;

continuing flowing a separate supply of said atmosphere air to said mixing head;

efficiently mixing said ethylene and atmosphere air within the head to form a turbulent mixture;

reacting the ethylene and ozone of said continuously flowing mixture with characteristic chemilum-inescent radiation as it leaves said head;

applying a controlled pulling pressure to the outlet to said chamber for controllably withdrawing said mixture from said chamber to control said separate atmospheric air flow rate; and

electro-optically detecting said radiation to develop a signal indicative of ozone concentration of said atmospheric air.

9. A method according to claim 8 in which the ethylene flow rate is adjusted to about 5 to 20 ml per minute for an atmospheric flow rate of about one liter per minute.

10. A method according to claim 8 in which said mixture is controllably withdrawn from said chamber by controlling the frequency of oscillation of an electronic pump connected to said outlet.

11. A method according to claim 8 in which said ethylene is of reagent grade.

12. A method according to claim 8 in which said ethylene and atmosphere are introduced to said head in separate streams through the annular and central flow channels of an elongated concentric tube nozzle, said tubes terminating in an enclosed mixing head having an outlet orifice.