HK1228504A1 - Multi-channel detector - Google Patents

Description

Multi-channel detector

Technical Field

The present invention relates generally to a multi-channel detector, and more particularly to a multi-channel particle and/or gas detector, typically an aspirated detector.

Prior Art

Multichannel air sampling systems with alarm capability are known in the art. One example of such a system uses a rotary valve type detector that draws mixed air samples from different sections in a protected area from a network of microporous flexible tubing. The detector then filters and analyzes the sample in a laser detection chamber. When smoke particles are detected in the mixed sample, the system switches to sequentially scan different segments through a rotary valve to identify the one or more segments having smoke conditions. As a result, although this arrangement provides multiple entry points into the detector, the detector still needs to walk through the various segments in sequence to identify the segment that produced the problematic sample. The disadvantage of this detection procedure is that it can only process multiple samples in sequence and the detection procedure is time consuming, limiting the number of channels that can be included in a single detector.

It is an object of the present invention to provide an alternative multi-channel particle detector which addresses certain disadvantages associated with the sequence processing nature of currently marketed systems.

The reference to any prior art in this specification should not be taken as an acknowledgment or any form of suggestion that prior art forms part of the common general knowledge in any jurisdiction or that this art could reasonably be expected to be understood, appreciated as relevant, and/or combined with other prior art features by a person of ordinary skill in the art.

Disclosure of Invention

According to a first aspect of the present invention, there is provided a multi-channel particle and/or gas detector comprising an array of detector elements held in a housing configuration, the housing configuration being configured to provide an inlet and an outlet for each detector element, wherein each inlet, detector element and outlet forms a dedicated detector channel which is in operative communication with a sampling tube.

The array of detector elements may be the same type of sensor, detecting the same particle, gas, combination of particles, or combination of gases for each detector.

Alternatively, the detector array may include different types of sensors, each type of sensor configured to detect a different particle, gas, combination of particles, or combination of gases.

Typically, the detector may comprise an array of a plurality of detector elements, the outlet of one array of detector elements being in fluid communication with the inlet of an adjacent detector array, thereby connecting a plurality of detector elements of different arrays in series in a single detector channel. The multiple arrays can be stacked in a single housing in an in-line fashion.

It will be appreciated that the modular construction of the detector facilitates the stacking of a number of sub-assemblies, the number of which depends on the number of detectors required in an in-line column. Each subassembly may preferably comprise a planar array of a plurality of detector elements, on opposite sides of which a manifold is mounted, preferably via a sealing gasket, which manifold in turn is arranged to receive a pneumatic fitting. The inlet or outlet of these pneumatic fittings may be configured to receive a sampling tube. For a stacked embodiment, both ends of the pneumatic fittings on one or both sides of the detector element array (depending on how many subassemblies are in the stack) can be configured so that they are in the manifold so that another manifold/detector array/manifold subassembly can be stacked on the existing subassembly. The stacked subassemblies are sequentially enclosed in a housing.

Typically, the plurality of detector elements connected in series in a single detector channel are each configured to detect different particles, gases, particle combinations, or gas combinations, thereby providing multiple standard detections of particles and/or gases in a particular detection channel of the detector.

The detector may comprise a plenum chamber connected on one end thereof to the outlets of the detector elements, wherein the plenum chamber is in fluid communication with an aspirator in use such that air flows through the array of detector elements. The aspirator is preferably a fan or a pump.

Typically, each sensor includes a detection substrate configured to detect a particular particle or gas, wherein the detection substrate is selected from one or more of the following materials: a printed circuit board, ceramic, composite device, semiconductor, micro-electro-mechanical system (MEMS), or the like.

The detection substrate can be communicatively coupled to the inlet and outlet of each detector channel.

The array of individual detector elements may be a planar array.

The detector can include a flow monitoring device associated with each or some of the detector channels.

As used herein, the terms "comprises," "comprising," and variations thereof, such as "comprises," "comprising," and "comprising," are not intended to exclude other additives, components, ingredients, or steps, unless the context specifically requires otherwise.

Other aspects of the invention and other embodiments of those aspects described in the preceding paragraphs herein will become apparent from the following description and from the accompanying drawings by way of example and with reference to the accompanying drawings.

Brief description of the drawings

FIG. 1 shows a perspective view of a multi-channel particle and/or gas detector according to an exemplary embodiment of the present invention;

FIG. 2 shows a schematic side view of the multi-channel particle and/or gas detector of FIG. 1, wherein the detector is connected to various sampling tubes and a plenum chamber;

FIG. 3 shows an exploded view of the multi-channel particle and/or gas detector of FIG. 1, illustrating an array of single planar detector elements and other components of the detector;

FIG. 4 shows a cross-sectional view of a portion of the multi-channel particle and/or gas detector of FIG. 1, illustrating the configuration of one single detector channel; and is

Fig. 5 shows an exploded view of a multi-channel particle and/or gas detector having a planar array of multiple detector elements according to another exemplary embodiment.

Detailed description of the preferred embodiments

A multi-channel particle and/or gas detector will initially be described, by way of example only, with reference to the accompanying drawings.

Turning first to fig. 1 and 2, a multi-channel particle and/or gas detector is generally indicated by reference numeral 10. The detector 10 comprises an array of detector elements, each detector forming part of a detector channel 12. The plurality of detector channels 12 formed by the array of detector elements may be connected in use to a sampling tube 14. The plurality of sampling tubes 14 form part of a sampling network and each sampling tube 14 has some air sampling inlet in the form of a sampling hole or sampling point along the length of the tube. These sample points are typically located within the regions of interest, thereby allowing the detection of gases and/or particles within these regions.

The outlets of the multi-channel detector channels 12 are in turn connected to a getter arrangement. In this example, the aspirator configuration is a plenum chamber 18 that receives the output from the detector 10. The plenum chamber 18 is in fluid communication with an aspirator 20 that causes air to flow through the sampling tube 14 and through the plurality of detector channels 12. Aspirator 20 may be in the form of a fan or pump, or any suitable device. As air is fed through the respective tube 14 and associated passage 12, the detector elements perform gas and/or particle sampling so as to enable a monitoring system to issue appropriate warning signals when a minimum level of a particular particle or gas is detected.

The detector elements are used to detect the presence and measure the concentration of gases or other volatile compounds from various sampling locations. In other uses, the detector 10 can be used in a monitoring system to detect, for example, the presence of a toxic gas, a flammable gas leak (in an attempt to prevent a fire), or a flammable gas buildup (e.g., methane in a waterless system), and/or other gas or volatile compounds or smoke that indicates an impending flame event (i.e., smoldering or melting material), or a pre-existing flame (e.g., burning material), or a natural flame (e.g., type of material being burned).

For the detection of a toxic gas, the detector element can be configured to detect ammonia gas released in an enclosed space, methyl isocyanate accidentally released by an industrial manufacturing plant, or carbon dioxide and/or carbon monoxide generated by a controlled fire event, such as a fuel burner, gas water heater, gas oven, gas dryer, space heater, carbon oven, stove, vehicle (including build-up in a parking lot), and lawn mower, for example.

The multi-channel particle and/or gas detector 10 will now be described in more detail with reference to fig. 3 and 4. Fig. 3 shows that the detector 10 contains an array of 40 channels (5 by 8) of detector elements, shown as a planar array 22 of sensors. It will be understood that the array need not be in a planar configuration. Each sensor 22 of the sensor array includes a detection substrate configured to detect a particular type of particle or gas. In one embodiment, the sensor detects carbon monoxide using electrochemical oxidation of carbon monoxide (CO) and has a measurement range of 1 to 1000ppm of carbon monoxide, a reaction time of less than 30 seconds, and a resolution of less than 1 ppm. In this example, the detection substrate is a printed circuit board, but may also typically be selected from ceramics, composite devices, semiconductors, micro-electro-mechanical systems (MEMS), or the like.

The multi-channel detector 10 is comprised of a housing construction formed by side panels 24a and 24b, end caps 26a and 26b, a back sealing tape 28, and a front sealing tape 30. On each side of the housing, and beginning with the PCB-mounted sensor array 22, a sealing gasket 32a, 32b, a manifold 34a, 34b, a pneumatic push fitting 36a, 36b, and a mounting plate 38a, 38b with holes are placed. A common Printed Circuit Board (PCB)40 carries all of the sensors 22 as previously described, with the PCB 40 sandwiched between respective pairs of sealing gaskets and manifolds 32a and 34a, 32b and 34 b. On each side of the printed circuit board 40, the respective manifolds and sealing gaskets 32a and 34a, 32b and 34b are secured to the printed circuit board 40 by screw fasteners. The array of pneumatic fittings 36a and 36b, which are in turn held in place by the orifice retaining plates 38a and 38b, are also held to each manifold 34a and 34b with screw fasteners.

Fig. 4 clearly shows how the various components described above are arranged closely together. Each manifold 34a, 34b provides a sub-enclosure 41a, 41b that together house one sensor 22A. A single detector channel 12A, shown in fig. 4, includes an inlet defined by a pneumatic fitting 36 a. Each pneumatic fitting 36a, 36b includes a resilient biasing fitting 43a, 43b for receiving a sampling tube. The pneumatic fittings 36a, 36b also include an innermost socket 45a, 45b that is closely received in a complementary opening 46a, 46b in the manifold 34a, 34 b. The retaining plates 38a and 38b are mounted to the respective manifolds 34a and 34b via screw fasteners 42a and 42b with the apertures 47a, 47b in the retaining plates 38a, 38b passing over the outer tubular portions 48a, 48b of the pneumatic fittings 36a, 36b and abutting the intermediate flanges 49a, 49b of the fittings 36a, 36b to secure them in place. The detector channel 12A defines a flow path 44 through an opening in a printed circuit board 40 proximate the sensor 22A, the sub-housing 41b of the manifold 34b, and an outlet defined by the pneumatic fitting 36 b. Air flows along a flow path 44 between the inlet and outlet of the detector channel 12A, past the sensor 22A. Gaskets 32a and 32b provide an effective sealing effect to isolate and restrict air flow along flow path 44 and enable the detection substrate to be uniquely coupled to the inlet and outlet of each detector element for specific gas or particle detection within each detector channel in the array.

The printed circuit board 40 is used to communicate any detection of a gas or particle to the monitoring station, in an exemplary embodiment by using a communication standard, such as RS485 MODBUS.

In an exemplary embodiment, the sensor arrays 22 of the multi-channel detector 10 may be the same type of sensor, such that each sensor detects the same particle, gas, combination of particles, or combination of gases. For example, all sensors may be fire sensors/smoke detectors configured to detect the burning of one material. In this configuration, various regions of interest can be connected to the detector 10 via the sampling tube 14, while all regions are monitored for a fire.

Alternatively, the array of sensors 22 may be configured as a plurality of groups of different types of sensors, wherein each group of sensors detects the presence of a different particle, gas, combination of particles, or combination of gases. For example, the rows of sensors may be different types of sensors, such that one detector 10 is thereby capable of detecting a variety of different particles, gases, or combinations from the same or different regions. This allows more design flexibility and basic metrology flexibility within a single detector.

FIG. 5 shows a configuration of a multi-channel particle and/or gas detector 50 comprising two detector arrays, each array housed within one detector sub-housing 52 and 54. Although not shown in FIG. 5, each detector sub-housing 52 and 54 contains an array of sensors, and a combination of a gasket and a manifold on each side of the array, thereby forming a single array sensor arrangement or subassembly 56 and 58. This is similar to the arrangement shown in fig. 3 and 4, in which the array of sensors 22 is mounted on each side of a sealing gasket 32a, 32b and a manifold 34a and 34 b. On the outer end of each single array sensor arrangement 56 and 58 are the respective pneumatic fittings 36a, 36b, an aperture fixing plate and side panels 60 and 62 which form part of the main housing of the detector 50. Similar to the previous description, the single array sensor configuration 56, 58 defines a plurality of channels, each channel having an inlet, a sensor, and an outlet.

Two adjacent single array sensor arrangements 56 and 58 are joined together with pneumatic fittings 64, each pneumatic fitting having a dual socket to connect the outlet of a detector channel of the single sensor arrangement 56 and the inlet of a detector channel of the single array sensor arrangement 58. The outlet of the detector channel of configuration 56 is thus in fluid communication with the inlet of the detector channel of configuration 58, forming one single detector channel in which the two sensors are connected in series. The single sensor channel is connected in use to a single sampling tube so that air from the tube flows past the sensors of the two single array sensor arrangements 56 and 58.

Although a combination of two single array sensor configurations is shown in FIG. 5, it will be appreciated that more than two single array configurations can be similarly and easily connected together in a stacked in-line configuration, forming additional arrays of series-connected detector elements to provide multiple dedicated channels.

It will be further appreciated that the structure of the manifolds forming the single array sensor arrangement can be modified to enable adjacent manifolds to be easily interlocked and/or stacked with one another.

As a result, the modular structure of the detector facilitates stacking of a number of subassemblies that depends on the desired number of in-line detectors. Each subassembly can comprise, for example, an array (in some cases a planar array) of detector elements, on opposite sides of which manifolds are mounted, preferably via gasket seals, which manifolds are in turn arranged to receive pneumatic fittings. The inlet or outlet of these pneumatic fittings may be configured to receive a sampling tube. For one stacking embodiment, these pneumatic fittings located on one or both sides of the array of detector elements (depending on how many subassemblies are in the stack) can be configured with both of their ends located within the manifold so that another manifold/detector array/manifold subassembly can be stacked on the existing subassembly. These stacked subassemblies are then sealed within an enclosure.

These multiple sensors connected in series within a single detector channel are typically different sensors, such that they are capable of detecting different particles, gases, particle combinations, or gas combinations. This thus enables multiple standard detections of particles and/or gas in one particular detection channel of the detector. For example, it is contemplated that all sensors located in one array are of the same type, while sensors between stacked arrays are of different types. These detector channels can thus be configured to detect a combination of particles or gases, forming part of each detector channel according to the respective sensor.

Two sensors arranged in series can also detect the same type but different concentrations of gas or particles, thereby enabling one detector channel with multiple sensors to provide different alarm indications for the same type of particle or gas detection.

In one exemplary embodiment, the multi-channel particle and/or gas detector may include a flow monitoring device associated with each detector channel. For example, a flow monitoring device may be secured to an inlet or outlet of each or some of the channels.

The multi-channel particle and/or gas detector of the present invention enables a convenient and simultaneous calibration procedure for all detector elements (sensors) in one single array. This calibration procedure requires that the aspirator described with reference to figure 2 be shut down and/or reversed and a calibration gas be supplied at a location common to the paths from the various channels, for example at the plenum chamber, and then caused to flow through the detectors.

Claims (13)

1. A multi-channel particle and/or gas detector comprising an array of detector elements held in a housing structure, the structure being configured to provide an inlet and an outlet for each detector element, wherein each inlet, detector element and outlet forms a dedicated detector channel which is in operative communication with a sampling tube.

2. A multi-channel particle and/or gas detector as claimed in claim 1 wherein the array of detector elements is an array of sensors of the same type whereby the same particle, gas, combination of particles or combination of gases is detected for each detector element.

3. A multi-channel particle and/or gas detector as claimed in claim 1 wherein the array of detector elements comprises different types of sensors, each type of sensor being configured to detect a different particle, gas, combination of particles or combination of gases.

4. A multi-channel particle and/or gas detector as claimed in claim 1 wherein the detector comprises an array of a plurality of detector elements and wherein the outlet of an array of one detector element is in fluid communication with the inlet of an array of adjacent detector elements thereby connecting a plurality of detector elements from different arrays in series within a single detector channel.

5. A multi-channel particle and/or gas detector as claimed in claim 4 wherein the plurality of detector elements connected in series within a single detector channel are each configured to detect different particles, gases, particle combinations or gas combinations, thereby providing multiple criteria of particle and/or gas detection in a particular detection channel of the detector.

6. A multi-channel particle and/or gas detector as claimed in claim 1 wherein the detector comprises a plenum chamber connected at one end thereof to the outlets of the detector elements, the plenum chamber being in fluid communication with an aspirator in use such that air flows through the array of detector elements.

7. A multi-channel particle and/or gas detector as claimed in claim 6 wherein the getter is a fan or a pump.

8. A multi-channel particle and/or gas detector as claimed in claim 1 wherein the array of detector elements is a planar array.

9. A multi-channel particle and/or gas detector as claimed in claim 1 wherein the detector includes a flow monitoring device associated with each or some of the detector channels.

10. The multi-channel particle and/or gas detector of claim 2, wherein each of the sensors comprises a detection substrate configured to detect a particular particle or gas, and wherein the detection substrate is selected from one or more of: a printed circuit board, ceramic, composite device, semiconductor, or micro-electromechanical system (MEMS).

11. A multi-channel particle and/or gas detector as defined in claim 3 wherein each of the sensors includes a detection substrate configured to detect a particular particle or gas, and wherein the detection substrate is selected from one or more of: a printed circuit board, ceramic, composite device, semiconductor, or micro-electromechanical system (MEMS).

12. A multi-channel particle and/or gas detector as claimed in claim 10 or claim 11 wherein the detection substrate is communicatively coupled to the inlet and outlet of each detector channel.

13. A multi-channel particle and/or gas detector as claimed in claim 1 wherein the inlet and outlet are provided by pneumatic fittings to receive sampling tubes, the pneumatic fittings being mounted to manifolds located on opposite sides of the array of detector elements.