Fire detector and housing

• US 6,153,881 A
• Filed: 05/30/1997
• Issued: 11/28/2000
• Est. Priority Date: 07/31/1996
• Status: Expired due to Term

• Current Assignee: Honeywell International Inc.
• Original Assignee: The Fire Sentry Corp. (Honeywell International Inc.)
• Inventors: Castleman, David A.
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): HANIG, RICHARD E
• Application Number:
  US08/866,023
• Time in Patent Office: 1,278 Days
• Field of Search: 250/339.15, 250/339.14, 250/554, 340/578
• US Class Current: 250/339.15
• CPC Class Codes: G08B 17/12 Actuation by presence of radiation or particles, e.g. of infrared radiation or of ions
• CPC Class Codes: G08B 25/002 Generating a prealarm to the central station
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]

Abstract

A process and system for flame detection includes a microprocessor-controlled detector with at least three sensors. A wide band infrared sensor is used as the primary detector, with near band and visible band sensors serving to detect false-alarm energy from nonfire sources. Digital signal processing is used to analyze sensed data and discriminate against false alarms. A multistage alarm system can be-provided, which is selectively triggered by the microprocessor. Spectral recording and analysis of prefire data is provided for. The detector can be housed in an enclosed, sealed, removable, plastic housing that may include an integral plastic window lens.

Claims

1. A fire detection apparatus, comprising:

a sensor comprising a wide band infrared detector for detecting radiant energy from a fire; and

a housing having an outer encasement, said sensor being disposed and sealed within the housing, wherein the outer encasement of said housing is formed as a single, integral piece, and wherein said outer encasement includes a viewing region integrally formed therewith, said viewing region being transmissive over a range of wavelengths sufficient to allow said wide band infrared detector to detect radiant energy from a fire source.

2. A fire detection apparatus as in claim 1 wherein the wide band infrared detector is capable of detecting infrared wavelengths in the range of about 700-3500 nanometers.

3. A fire detection apparatus as in claim 2 wherein the sensor further comprises:

a near band infrared detector capable of detecting infrared wavelengths in the range of about 700-1100 nanometers; and

a visible light detector capable of detecting visible wavelengths in the range of about 400-700 nanometers;

wherein said wide band infrared detector is utilized as a primary detector, and wherein said near band infrared detector and said visible light detector are utilized to avoid false alarms.

4. A fire detection apparatus as in claim 1 wherein the housing comprises a material selected from the group consisting of polypropylene, polyvinylchloride, ABS plastic, Teflon, fiberglass and spun glass.

5. A fire detection apparatus as in claim 1 wherein the outer encasement, including the viewing region, are formed as a single piece from an acid-resistant, non-metallic material.

6. A fire detection apparatus as in claim 5 wherein the acid-resistant, non-metallic material is polypropylene.

7. A fire detection apparatus as in claim 1 wherein the outer encasement, including the viewing region, are formed as a single piece from Teflon.

8. A fire detection apparatus as in claim 7 wherein the housing is explosion proof.

9. A fire detection apparatus as in claim 1 wherein the housing is constructed to minimize airspace within the housing.

10. A fire detection apparatus as in claim 1 wherein the outer encasement, including the viewing region, are formed a, a single piece from fiberglass.

11. A fire detection apparatus as in claim 1 wherein the viewing region is thinner than the remainder of said outer encasement, said viewing region thereby defining a hollow space beneath it interior to said housing, said fire detection apparatus further comprising a reinforcing plug of high transmittance material located beneath said viewing region in said hollow space.

12. A fire detection apparatus as in claim 1 wherein the viewing region is transmissive for wavelengths of energy in the range of about 700-3500 nanometers.

13. A fire detection apparatus in claim 1, wherein said fire detection apparatus does not utilize an ultraviolet light (UV) detector.

14. A fire detector comprising:

a housing comprising an outer casing having a viewing region, said outer casing made of an acid-resistant, non-metallic material and formed in a single, integral piece including the viewing region, said viewing region being transmissive over a wide band infrared spectrum; and

a wide band infrared sensor disposed within said housing and positioned to receive through said viewing region radiant energy produced from external sources.

15. A fire detector, comprising:

a sensor array comprising a wide band infrared detector, a near band infrared detector, and a visible light detector, without a UV light detector; and

a housing within which said sensor array is disposed, said housing having an outer encasement integrally formed as a single piece, said outer encasement made from a uniform, non-metallic, acid-resistant material having a transmissivity in a region above said sensor array sufficient to allow said wide band infrared detector, said near band infrared detector and said visible light detector to detect radiant energy within their respective bandwidths emitted from a fire source.

16. The fire detector of claim 15, further comprising a printed circuit board mounted to an interior wall of said outer encasement, said sensor array being disposed upon a surface of said printed circuit board.

17. The fire detector of claim 15, wherein said region of the outer encasement above said sensor array comprises a viewing region having a thickness less than the remainder of said outer encasement, wherein a transmissivity of said viewing region is sufficient to allow said wide band infrared detector, said near band infrared detector and said visible light detector to detect within their respective bandwidths radiant energy emitted from a fire source.

18. The fire detector of claim 17, wherein a transmissivity of a substantial remainder of said outer encasement other than said viewing region is less than the transmissivity of said viewing region.

19. The fire detector of claim 17, wherein said viewing region is substantially circular in shape, said outer encasement defining a cylindrical hollow on the interior of said housing beneath said viewing region.

20. The fire detector of claim 19, further comprising a reinforcing plug disposed within said cylindrical hollow.

21. The fire detector of claim 20, wherein said reinforcing plug is made of a high transmittance material.

22. The fire detector of claim 21, wherein said cylindrical hollow is surrounded by threaded walls formed integrally with said outer encasement, and wherein said reinforcing plug is cylindrical in shape with matching threads along an outer surface such that the reinforcing plug is securely fastened when disposed in said cylindrical hollow.

23. The fire detector of claim 15, wherein said outer encasement is made from one or more materials selected from the following:

polypropylene, polyvinyl chloride, ABS plastic, Teflon, or fiberglass.

24. The fire detector of claim 15, wherein said housing further comprises a base made from a non-metallic, acid-resistant material, said base connected to said outer encasement and beat sealed thereto so as to define a completely enclosed hollow space, said sensor disposed within said hollow space.