Ultraviolet emitter for use in a flame detector and a method of making the same

Patent metadata

Field	Value
Publication number	US-10055960-B2
Application number	US-201515542059-A
Country	US
Kind code	B2
Filing date	Dec 29, 2015
Priority date	Jan 6, 2015
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A flame detector including an ultraviolet emitter configured to emit ultraviolet light at a strike voltage less than or equal to approximately 230 volts. A method of manufacturing an ultraviolet emitter for use in a flame detector, the ultraviolet emitter including a hermetically sealed, alkali rich, ultraviolet transmissive glass envelope, the method including: (a) wrapping an envelope exterior surface with a conductive material; (b) performing a first injection of at least one non-radioactive gas into the glass envelope at a first pressure; (c) applying a voltage bias to the glass envelope; (d) baking the hermetically sealed, alkali rich, ultraviolet transmissive glass envelope at a baking temperature for a baking duration of time; (e) cooling the hermetically sealed, alkali rich, ultraviolet transmissive glass envelope to a desired temperature; and (f) performing a second injection of at least one non-radioactive gas into the glass envelope at a second pressure.

First claim

What is claimed is:

1. A flame detector comprising:
an ultraviolet emitter comprising;
a hermetically sealed, alkali rich glass envelope including an envelope proximal end, an envelope distal end, and a cavity defined therein;
at least one electrode extending through the envelope proximal end into the cavity; and

at least one non-radioactive gas disposed within the glass envelope, said at least one non-radioactive gas comprising a majority of neon, a minority of hydrogen, and trace amounts of argon;
a sensor configured to detect ultraviolet light; and
wherein the ultraviolet emitter is configured to emit ultraviolet light at a strike voltage less than or equal to approximately 230 volts.

2. The flame detector of claim 1 , wherein said flame detector further comprises:
a microcontroller operably coupled to the sensor; and
a power supply operably coupled to the microcontroller, the ultraviolet emitter, and the sensor.

3. The flame detector of claim 1 , wherein the at least one electrode comprises an anode and a cathode.

4. The flame detector of claim 1 , wherein said at least one non-radioactive comprises approximately 85% neon, approximately 15% hydrogen, and trace amounts of argon.

5. A method of manufacturing an ultraviolet emitter for use in a flame detector, the ultraviolet emitter comprising a hermetically sealed, alkali rich, ultraviolet transmissive glass envelope including an envelope proximal end, an envelope distal end, a cavity disposed therein, an envelope length, an envelope exterior surface, and at least one electrode extending through the envelope proximal end into the cavity, the method comprising:
(a) wrapping the envelope exterior surface with a conductive material;
(b) performing a first injection of at least one non-radioactive gas into the glass envelope at a first pressure;
(c) applying a voltage bias to the glass envelope;
(d) baking the hermetically sealed, alkali rich, ultraviolet transmissive glass envelope at a baking temperature for a baking duration of time;
(e) cooling the hermetically sealed, alkali rich, ultraviolet transmissive glass envelope to a desired temperature; and
(f) performing a second injection of at least one non-radioactive gas into the glass envelope at a second pressure.

6. The method of claim 5 , wherein the conductive material is selected from a group consisting of a wire mesh and a spring, wherein the conductive material comprises a conductive material length.

7. The method of claim 6 , wherein the conductive material length is less than an envelope length, wherein the envelope length is the length between the envelope proximal end and the envelope distal end.

8. The method of claim 6 , wherein the at least one non-radioactive gas is selected from a group consisting of hydrogen, helium, neon, argon, and xenon.

9. The method of claim 6 , wherein the first pressure is greater than or equal to approximately 17 Torr.

10. The method of claim 6 , wherein step (c) comprises:
connecting a power source to the conductive material and the at least one electrode.

11. The method of claim 10 , wherein the at least one electrode comprises an anode in electrical communication with a cathode.

12. The method of claim 11 , wherein the applied voltage bias is greater than or equal to approximately 1,900 volts.

13. The method of claim 6 , wherein the baking temperature is greater than or equal to approximately 260 degrees Celsius.

14. The method of claim 6 , wherein the baking duration of time is less than or equal to approximately 3.5 hours.

15. The method of claim 6 , wherein the desired temperature is approximately room temperature.

16. The method of claim 6 , wherein the second pressure is greater than or equal to approximately 35 Torr.

17. The method of claim 6 , further comprising the steps:
(g) removing the power source prior to step (f); and
(h) removing the conductive material from the envelope exterior surface.

18. The method of claim 5 , wherein the at least one non-radioactive gas comprises approximately 85% neon, approximately 15% hydrogen, and trace amounts of argon.

Assignees

• Carrier Corp

Inventors

• Follett Gary J

Classifications

• F23N2227/14

  Flame simulation · CPC title

• F23N5/082

  using electronic means · CPC title

• H01J61/76

  having a filling of permanent gas or gases only · CPC title

• H01J47/08

  Geiger-Müller counter tubes {(gas filling with very short deionisation times H01J17/64, H01T)} · CPC title

• G08B29/145 Primary

  of fire detection circuits · CPC title