RU210429U1 - Optoelectronic smoke sensor for conditions complicated by the presence of suspended particles of cement indoors - Google Patents

Abstract

The proposal relates to the field of fire alarms, namely to optical-electronic fire alarm sensors with scattered light, which are designed to detect a fire accompanied by the appearance of smoke in enclosed spaces, in particular, the operation of which is complicated by the presence of suspended particles of cement and / or building dust inside the premises. The utility model provides an increase in the efficiency of protecting the sensor from false alarms while ensuring high reliability of the smoke sensor in the event of a fire by increasing the period of maintaining it in working condition, reducing the penetration of suspended particles of cement and / or construction dust to the optical module, including in closed conditions. rooms, simplifying the cleaning of the base. It also expands the arsenal of easy-to-manufacture and use optoelectronic smoke detector designs. Optoelectronic smoke sensor for conditions complicated by the presence of suspended cement particles inside the room, consists of an insert fixed in the base, with an optical module consisting of a light source, a light receiver and a measuring chamber, a base equipped with slots for the passage of smoke and a smoke guide element. The base is made of a flat shape with an annular protrusion around the circumference on the outside, on the inside the base is made with an annular recess. The smoke guide element is made inside the case in the form of a disk parallel to the base and is rigidly mounted on the base at an equidistant distance between the base and the optical module, with the formation of a through annular gap between the inner surface of the case and the end part of the smoke guide element, which ensures the deflection of the flow of incoming air inside the case with the deposition of suspended particles cement and/or construction dust. The smoke guide element is made of plastic. The slotted holes are located in the flat base. The annular recess on the inner side of the base is made on one side perpendicular to the base, and on the other side is formed by the side surface of the sensor housing, the base of the annular recess is parallel to the sensor base. 3 w.p. f-ly, 1 ill.

Description

The utility model relates to the field of fire alarms, namely to optical-electronic fire alarm sensors with diffused light, which are designed to detect a fire accompanied by the appearance of smoke in enclosed spaces, in particular, the operation of which is complicated by the presence of suspended particles of cement and / or construction dust inside the premises. .

Known smoke fire detector (Optical electronic smoke detector IP 212-45, Passport 4371-006-12215496-00 PS). The detector consists of a socket and a sensor, which is a plastic case, inside which is placed an optoelectronic system and a board with radio elements (electronic signal processing circuit). The slotted openings of the sensor housing do not provide effective protection against dust entering the optical (smoke) chamber, especially in the presence of suspended particles of cement and / or construction dust having a fine particle size. To exclude the occurrence of such false alarms, the smoke chambers of the detectors must be periodically cleaned of dust. Carrying out preventive maintenance of the detector consists in its disassembly and subsequent cleaning of the smoke chamber. This requires both labor costs and carries the risk of breakage of plastic latches that cannot be repaired, which leads to the need to replace the detector.

A smoke chamber is known for an optoelectronic smoke detector (patent RU No. 85716, publ. 08/10/2009), containing vertical labyrinth partitions located along the perimeter of the side surface, each of which consists of two rounded plates - the first plate located on the outside, and a second plate extending from the end of the first plate, the convex sides of which are directed outward, towards the smoke inlet, and the concave sides are directed inward, towards the center of the smoke chamber, while the radius of curvature of the second plate is greater than the radius of curvature of the first plate. The smoke chamber is equipped with a protective mesh with a mesh size of 1×1 mm, installed on its outer side in the cover of the smoke chamber.

The disadvantage of this solution is that when the protective mesh is placed directly on the smoke chamber, additional resistance to air flow is created due to a decrease in the flow area. In addition, during operation, the mesh openings are partially clogged with dust and other suspended particles (garbage), which further aggravates the situation, reduces the reliability and efficiency of the detector, especially at the initial stage of fire development with a low concentration of smoke in the air. In addition, the mesh does not provide protection against small suspended particles of cement and/or construction dust, which enter the smoke chamber, causing false alarms.

Known optical-electronic fire smoke detector, containing a housing having a detachable connection with a base in which electrical contacts are fixed, and placed in the housing a printed circuit board with electronic circuit elements and an optical camera containing optically isolated from each other light emitter and light receiver modules mounted on printed circuit board and not rigidly connected to the optical chamber, the measuring volume is formed by the surface of the printed circuit board and the removable cover of the optical chamber installed on it, which is made in the form of a restrictive element with smoke windows and a central hood, associated with coaxial, nested and interconnected radial cylindrical jumpers shells, the smoke intake windows of which are connected with the smoke intake windows of the restricting element and the measuring volume by labyrinth channels formed by radial bridges between the cylindrical shells and excluding direct light from outside into the meter volume. The light emitter and light receiver modules installed in the corresponding places of the printed circuit board are located between the box-shaped fence of the lower part of the outer cylindrical shell of the removable cover and the corresponding diaphragm of its inner cylindrical shell (patent RU No. 2450361, publ. 10.05.2012).

The disadvantage of this detector is the low efficiency of use in enclosed spaces, in particular, the operation of which is complicated by the presence of suspended particles of cement and / or construction dust inside the premises, penetrating into the sensor housing, creating conditions for false alarms, which narrows the scope of the sensor, leads to the problem of frequent preventive inspection of the optical camera, which is also exacerbated by the complexity of the design of this detector during manufacture and maintenance.

The closest in technical essence is a smoke detector, consisting of an insert fixed in the base, with an optical module consisting of a light source, a light receiver, a measuring chamber and a base equipped with slots for the passage of smoke and a smoke guide element (patent RU No. 2189080, publ. 10.09 .2002). Inside the case there is a printed circuit board with electronic circuit elements. In this case, the printed circuit board is located on the side of the optical chamber facing the detector base, which has the shape of a cone or pyramid. The smoke inlet zone contains smoke guide ribs arranged in a star-like manner on the outlet side of the base. Dust particles penetrating into the working volume of the signaling device settle in the lower part of the bottom of the base due to its funnel-shaped design.

This design of the base makes it possible to increase the distance between the base and the optical module, reduce false alarms due to light scattering on dust particles, as a result, an increase in the intervals for routine inspection is achieved. However, this design of uneven removal of the base from the optical module reduces the uniform penetration of smoke into the smoke chamber, which reduces the efficiency of the sensor.

The disadvantage of this smoke detector is the low efficiency of use in enclosed spaces, in particular, the operation of which is complicated by the presence of suspended particles of cement and / or construction dust indoors, penetrating into the sensor housing, creating conditions for false alarms, which narrows the scope of the sensor, leads to a problem frequent preventive inspection of the optical chamber, which is also exacerbated by the complexity of the design of this signaling device during manufacture and maintenance.

The technical objective of the utility model is to increase the effectiveness of protection against false alarms while ensuring high reliability of the smoke detector in the event of a fire, in particular, the operation of which is complicated by the presence of suspended particles of cement and / or building dust inside the room, by reducing the penetration of suspended particles of cement and / or construction dust. dust to the optical module. As well as expanding the arsenal of easy-to-manufacture and use optoelectronic smoke detector designs.

The technical problem is solved by an optical-electronic smoke sensor for conditions complicated by the presence of suspended cement particles inside the room, consisting of an insert fixed in the base, with an optical module consisting of a light source, a light receiver and a measuring chamber, a base equipped with slots for the passage of smoke and a smoke guide element.

What is new is that the base is made flat with an annular protrusion around the circumference on the outside, on the inside the base is made with an annular recess, the smoke guide element is made inside the case in the form of a disk parallel to the base and is rigidly mounted on the base at an equidistant distance between the base and the optical module , with the formation of a through annular gap between the inner surface of the housing and the end part of the smoke guide element, which ensures the deflection of the flow of incoming air inside the housing with the deposition of suspended particles of cement and / or building dust.

Also new is that the smoke guide element is made of plastic.

Also new is that the slotted holes are located in the flat base.

Also new is that the annular recess on the inside of the base is made on one side perpendicular to the base, and on the other side is formed by the side surface of the sensor housing, the base of the annular recess is parallel to the sensor base.

The figure shows a diagram of the proposed optical-electronic smoke sensor.

The optical-electronic smoke sensor for conditions complicated by the presence of suspended cement particles inside the room consists of an insert 1 with a mount 2 fixed in the base (not shown in the drawing), a plastic housing of the measuring chamber 3 in the shape of an inverted truncated cone, a base with slotted holes 4 for passing smoke. Inside the housing 3 there is an optical module consisting of a board 5, an indicator 6, an optical camera 7, which includes a light source with a light receiver (not shown in the drawing) and a smoke guide element 8. The base is made of a flat round shape with an annular ledge around the circumference on the outside, and from the inside, the base is made with an annular recess 9. The smoke guide element 8 is made inside the housing 3 in the form of a disk parallel to the base and is rigidly mounted on the base, for example, using 4-6 pins 10 installed in the grooves 11 on the inner surface of the base, at an equidistant distance between the base and the optical module, which ensures the deflection of the flow of incoming air, including smoke in a certain concentration and suspended particles of cement and / or building dust, to the inner side surface of the housing. The diameter of the base is equal to the diameter of the smoke guide element. The smoke guide element 8 is made of plastic and forms a through annular gap between the inner surface of the housing and the end part of the smoke guide element, which deflects the flow. Slotted holes 4 for air inlet are located in the flat base. An annular recess 9 with a depth and width of, for example, 10 mm is sufficient to collect a suspension of cement and / or construction dust in a volume that provides an increase in the overhaul period of the sensor in difficult conditions of a confined space, and on the inside of the base it is made on one side perpendicular to the base, and on the other side is formed by the side surface of the sensor body 3, the base of the annular recess is parallel to the base of the sensor. The design of the proposed sensor with a smoke guide element, which forms a gap between the end part of the smoke guide element-disk and the inner side surface of the housing in the form of an annular space, ensures the deposition of suspended particles of cement and / or building dust, which have a significant specific gravity compared to smoke, when changing the direction of movement, into the annular recess - dust collector 9. The efficiency of dust protection and protection against external light and false alarm of the sensor is increased while ensuring high reliability of the smoke detector in case of fire. And the smoke, which has a higher temperature, freely rises inside the housing 3 through the gap and enters the optical chamber 7.

The radiation from the light source, scattered by smoke particles, is recorded by a photodetector. This achieves high speed and uniform sensitivity of the sensor, regardless of the direction of the spread of smoke.

The optical-electronic smoke sensor for conditions complicated by the presence of suspended particles of cement inside the room works as follows.

The presence of a smoke guide element 8, which performs the function of changing the direction of the air flow inside the housing 3, ensures that, when the direction of movement of suspended particles of cement and / or construction dust changes under the action of gravity, it is deposited due to the high specific gravity in the dust collector 9, which increases efficiency and expands the possibility of using smoke detector when placed and in a closed room with a high content of suspended particles of cement and / or building dust in the air. When signs of smoke appear, smoke having a higher temperature rises freely inside the sensor housing 3 and freely passes through the (gap) annular space between the end face of the smoke guide element 8 and the inner side surface of the housing, and enters the optical chamber 7. Optical chamber 7 with labyrinth channels, including a light source with a light receiver, works similarly to most of those used, therefore, the diagram is shown without detail. The pulse sequences of electrical signals generated by the electronic circuit on board 5 are converted by the light source into light pulses. Scattered radiation is received by the light detector, which is optically inaccessible to direct radiation of the light source, the optical axis of which is located at an angle to the optical axis of the light detector. The received scattered reflected radiation is converted by the light receiver into electrical signals, which are processed by the elements of the electronic circuit of the board 5 with the subsequent formation of the signals "Standby mode" or in the presence of smoke aerosols "Fire". Thus, the proposed optical-electronic smoke sensor has a high protection against false alarms while ensuring reliable operation in the event of a fire.

The design of the housing in the form of an inverted truncated cone ensures that smoke streams flow around, in case of lateral distribution along the ceiling of the room, down to the base of the housing, entering the annular recess and further into the slotted holes.

The utility model provides an increase in the efficiency of protecting the sensor from false alarms while ensuring high reliability of the smoke sensor in the event of a fire by increasing the period of maintaining it in working condition, reducing the penetration of suspended particles of cement and / or construction dust to the optical module, including in closed conditions. rooms, simplifying the cleaning of the base. It also expands the arsenal of easy-to-manufacture and use optoelectronic smoke detector designs. The use of the proposed sensor for conditions complicated by the presence of suspended particles of cement and/or building dust indoors allows to increase the period between maintenance by at least two times.

Claims (4)

1. Optoelectronic smoke sensor for conditions complicated by the presence of suspended cement particles inside the room, consisting of an insert fixed in the base, with an optical module consisting of a light source, a light receiver and a measuring chamber, a base equipped with slots for the passage of smoke and a smoke guide element , characterized in that the base is made flat with an annular protrusion around the circumference on the outside, on the inside the base is made with an annular recess, the smoke guide element is made inside the case in the form of a disk parallel to the base and is rigidly mounted on the base at an equidistant distance between the base and the optical module , with the formation of a through annular gap between the inner surface of the housing and the end part of the smoke guide element, which ensures the deflection of the flow of incoming air inside the housing with the deposition of suspended particles of cement and / or building dust. 2. Optoelectronic smoke sensor for conditions complicated by the presence of suspended cement particles indoors according to claim 1, characterized in that the smoke guide element is made of plastic. 3. Optoelectronic smoke sensor for conditions complicated by the presence of suspended cement particles indoors according to claim 1, characterized in that the slotted holes are located in a flat base. 4. Optoelectronic smoke sensor for conditions complicated by the presence of suspended cement particles indoors according to claim 1, characterized in that the annular recess on the inside of the base is made on one side perpendicular to the base, and on the other side is formed by the side surface of the sensor housing, the base annular recess parallel to the base of the sensor.

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