Fire Protection Switch Sensor Placement for Smoke Detection

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Solution Overview

Problem

Existing fire protection switches often experience delays in smoke detection due to the need for smoke to penetrate the housing of the smoke detector, which can lead to premature closure of fire and smoke doors, compromising safety and aesthetics.

Innovation Solution

A fire protection switch with a sensor arrangement outside the housing that monitors the smoke gas transport path, allowing for reliable detection of smoke or fire gases without the need for smoke to enter the housing, using scattered light or gas sensors that can be integrated into the door frame or lintel, ensuring early and reliable door closure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the smoke detector is installed in the housing above the door, then the smoke detection can be performed, but the housing requires a minimum distance from the door lintel or ceiling to allow smoke flow through the detection area

Engineering Contradiction:
Improvesmoke detection reliabilityVSAvoiddistance from door lintel/ceiling
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The sensor is positioned on the door frame to detect smoke in a different spatial dimension (along the smoke transport path through the opening) rather than above the door where smoke would need to flow horizontally into the detector. This dimensional change eliminates the need for horizontal clearance space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The sensor is positioned to detect smoke at the earliest possible moment when it first appears in the smoke gas transport path, before the smoke has had time to spread and accumulate. This preliminary detection action enables earlier door closure compared to conventional detectors that require smoke to travel further.

Inventive Principle:
Principle #10Preliminary action

2Length of stationary object

If the smoke detector openings are positioned away from the smoke gas transport path, then the housing can be installed closer to the door, but smoke detection is delayed because smoke must flow in the opposite direction to enter the detector

Engineering Contradiction:
Improveinstallation distance from doorVSAvoidsmoke detection time
Core Design Contradiction:
Length of stationary objectVSLoss of time

Solution Approach 1:

The sensor is positioned at a specific location on the door frame where it directly intersects the smoke gas transport path. This localized positioning ensures that smoke flowing through the opening immediately enters the detection area, creating optimal local detection conditions at the critical point where smoke first appears.

Inventive Principle:
Principle #3Local quality

3Reliability

If smoke must penetrate the housing of the smoke detector to be detected, then the detector can be protected from environmental factors, but detection is delayed due to the time required for smoke to enter the housing

Engineering Contradiction:
Improvedetector protectionVSAvoiddetection delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The sensing element is extracted from the protected housing environment and positioned directly on the door frame in the smoke transport path. This extraction eliminates the housing penetration requirement, allowing immediate smoke detection while the housing remains as a mounting structure rather than a protective barrier that smoke must penetrate.

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution enables early and reliable detection of smoke and fire gases, ensuring timely closure of fire and smoke protection doors while maintaining aesthetic considerations and avoiding delays in smoke detection.

Implementation Method 1

The at least one sensor is expediently designed as a scattered light or extinction smoke sensor

Methodology Applied
Scientific EffectScattered light: Scattering

Implementation Method 2

The at least one sensor is expediently designed as a scattered light or extinction smoke sensor

Methodology Applied
Scientific EffectExtinction: Absorption (EM radiation)

Implementation Method 3

The at least one sensor is expediently designed as a scattered light or extinction smoke sensor and/or as a gas sensor

Methodology Applied
Scientific EffectGas sensing: Absorption Spectroscopy

Data Source

PatentEP2884033B1Fire protection circuit and assembly of the same
Publication Date: 2017.06.07 HEKATRON VERTRIEBS
  • EP2884033B1 patent drawingFigure 1~2
  • EP2884033B1 patent drawingFigure 3~4
  • EP2884033B1 patent drawingFigure 5

AI summary

The invention relates to an arc fault switch (1) for arrangement on a fire and/or smoke protection door (10) with a release device, the actuation of which releases the fire and/or smoke protection door (10) from an open position held by a holding device to a closed position, and with at least one fire detector (2) housed in a casing (15), which is provided with at least one sensor (8), and is arranged on an opening frame of the opening (20) that can be closed by the fire and/or smoke protection door (10), wherein a signal from the fire detector (2) at least indirectly actuates the release device in the event of an alarm. It is proposed that the at least one sensor (8) has a detection area (11) effective outside the casing (15) and that the detection area (11) coincides at least partially with a smoke gas transport path (9) extending through the opening (20).