Smoke detector

• US 20090237261A1
• Filed: 03/16/2009
• Published: 09/24/2009
• Est. Priority Date: 03/21/2008
• Status: Active Grant

• Current Assignee: Nohmi Bosai Limited (Secom Company Limited)
• Original Assignee: Nohmi Bosai Limited (Secom Company Limited)
• Inventors: Yokota, Hiroyuki
• Granted Patent: US 8,089,366 B2
• Time in Patent Office: Days
• US Class Current: 340/628
• CPC Class Codes: G08B 17/10 Actuation by presence of smoke or gases , e.g. automatic alarm devices for analysing flowing fluid materials by the use of optical means
• CPC Class Codes: G08B 17/113 Constructional details
• CPC Class Codes: Y10T 137/87571 Multiple inlet with single outlet

Abstract

To enable an air velocity of sampling air to be precisely measured, a smoke detector (S) includes: a smoke detection part (22) connected to a sampling pipe (11); a fan (12) that sucks sampling air (SA) into the sampling pipe; and an air velocity sensor (15) that measures an air velocity of the sampling air within the sampling pipe. The air velocity sensor (15) is disposed at a primary side of the fan (12), and a straightening vane (25) is disposed between the air velocity sensor (15) and a suction port (12a) of the fan (12).

Claims

1. A smoke detector, comprising:

a smoke detection part connected to a sampling pipe;

a fan that sucks sampling air into the sampling pipe; and

an air velocity sensor that measures an air velocity of the sampling air within the sampling pipe,

wherein the air velocity sensor is disposed at a primary side of the fan, and a straightening vane is disposed between the air velocity sensor and a suction port of the fan.

2. A smoke detector according to claim 1, further comprising an inflow part in which an airflow direction of the sampling air at the primary side of the fan and an airflow direction due to the suction port of the fan are substantially orthogonal to each other.

3. A smoke detector according to claim 2, wherein the straightening vane is rotatably supported on one of a bottom surface and a ceiling surface of the inflow part.

4. A smoke detector, comprising:

a smoke detection part having an inflow port and an outflow port;

a sampling pipe disposed in a monitor space;

an airflow pipe coupled with the sampling pipe; and

an intake side flow path branch part disposed in the airflow pipe and coupled with the inflow port of the smoke detection part,

wherein the intake side flow path branch part has an intake port directed opposite to a flow direction of sampling air flowing in the airflow pipe.

5. A smoke detector according to claim 4, wherein the intake port is directed opposite to the flow direction of the sampling air in a range of 0 to 45°

.

6. A smoke detector according to claim 4, wherein the intake port of the intake side flow path branch part is disposed one of upstream and downstream of an exhaust port of an exhaust side flow path merging part.

7. A smoke detector according to claim 5, wherein the intake port of the intake side flow path branch part is disposed one of upstream and downstream of an exhaust port of an exhaust side flow path merging part.

8. A smoke detector, comprising:

a smoke detection part having an inflow port and an outflow port;

an airflow pipe coupled with a sampling pipe disposed in a monitor space, in which a fan intervenes;

a flow path branch part coupled with an inflow port of the smoke detection part; and

a flow path merging part disposed in the airflow pipe and coupled with the outflow port of the smoke detection part through an exhaust pipe,

wherein the flow path merging part is equipped with a nozzle part having an opening larger than the exhaust pipe, which sprays air toward a vent hole lower in pressure than the flow path branch part of the fan.

9. A smoke detector according to claim 8, wherein the opening of the nozzle part is adjustable.