RU2817868C1 - Optoelectronic smoke detector - Google Patents

Abstract

FIELD: fire alarm.

SUBSTANCE: invention relates to the field of fire alarm, namely to optoelectronic smoke detectors of fire alarm with diffused light, which are designed to detect fire, accompanied by the appearance of smoke in closed rooms with high content of dust. Optoelectronic smoke detector comprises a socket with a fastener, a plastic housing with slotted holes in the upper part of the side cylindrical surface of the housing and with a base, a board, indicator, an optical module, a protective grid, a dust collector, a smoke guide element in the form of a hollow cylinder, fixed by means of pins in slots to the lower inner part of the socket, bottom of the smoke guide element is located below the slotted holes of the housing. In addition, on the base of the housing and coaxially to the housing there is a cylindrical casing in the form of an inverted cup fixed on the outer side by stops made on the base of the housing. On the upper base of the casing, a lower smoke-guiding element is rigidly installed, made in the form of an inverted truncated cone, the angle between the generatrix of the cone of the lower smoke-guiding element and the base of the casing is equal to 45°, truncated cone is made with height providing placement of base of truncated cone between upper smoke guide element and protective net in form of hollow cylinder without bases, made of nylon with cell of 0.3×0.8 mm and installed by the upper base into the slots on the lower inner part of the socket, and by the lower base into the slots on the upper base of the cylindrical casing. On the outer surface of the base of the casing, which is limited by the lower end of the lower smoke guide element, there are faces of the dust collector. Holes are made on the side surface of the casing and on the base of the casing between the smoke guide element and the slots for the nylon net. Inside the casing there is a metal mesh with cell 1×1 mm in the form of a hollow cylinder without bases, rigidly connected to the side surface.

EFFECT: increased efficiency of detector operation in closed rooms with increased content of dust due to improved quality of air filtration, penetrating inside the housing through slotted holes.

1 cl, 1 dwg

Description

The proposal relates to the field of fire alarms, namely to optical-electronic smoke detectors for fire alarms with scattered light, which are designed to detect fires accompanied by the appearance of smoke in enclosed spaces with a high dust content.

A known smoke fire detector contains a socket and a sensor, which is a plastic case with slotted holes, inside which there is an optical-electronic system and a board with radio elements (electronic signal processing circuit). (Optical-electronic smoke fire detector IP 212-45, Passport 4371-006-12215496-00 PS). The slotted holes in the sensor housing do not provide effective protection against small insects and dust entering the optical (smoke) chamber.

The practical use of such fire smoke detectors has shown that during operation the frequency of false alarms may increase, and the reason for this is the penetration and deposition of dust particles in the smoke chamber, as well as the entry of insects. To prevent such false alarms from occurring, the smoke chambers of the detectors must be periodically cleaned of dust. Preventative maintenance of the detector involves disassembling it and then cleaning the smoke chamber. This requires both labor costs and carries the risk of broken plastic latches that cannot be repaired, which leads to the need to replace the detector.

An optical-electronic smoke sensor is known (patent RU No. 210807, published 05/05/2022), containing a socket with fastening, a plastic case with slotted holes in the side and bottom of the case, a board, an indicator, an optical module, and a protective mesh. Additionally, a cylindrical container for dust deposition is located inside the housing and is secured to the lower part of the housing with plastic pins installed in grooves made in the lower part of the housing. The protective metal mesh with a cell size of 1x1 mm is made in the form of an inverted truncated cone with an inclination angle of 135 degrees between the generatrix of the cone and the upper part of the case; the protective mesh is installed with its upper base in a groove on the board, and with its lower base in a groove on the dust collection container. The protective mesh is made of metal wire with a diameter of 0.5 mm. The container for dust deposition is made of a plastic cylinder with a base diameter equal to the diameter of the lower base of the protective mesh. The container for dust deposition is 10 mm high.

The disadvantage of this solution is the low efficiency of collecting small dust particles in rooms with a high dust content, which leads to an increase in the frequency of false alarms when dust penetrates into the smoke chamber.

The closest to the claimed invention is an adjustable smoke fire detector (RU patent No. 2784012, published on November 23, 2022), containing a socket with fastening, a plastic housing with slotted holes in the side of the housing, consisting of upper and lower parts that provide the ability to overlap the slotted holes in the transport position along a threaded connection, a thrust collar, a smoke guide element, a dust collector, a board, an indicator, an optical module, while above the slotted holes in the side surface of the housing there are additional rectangular holes covered with a metal mesh with a mesh size of 1x1 mm made of metal wire with a diameter of 0. 5 mm, a metal mesh is fixed into clamps on the inside of the body, on top of the end of the lower part of the body there is an annular protrusion with a diameter exceeding the outer diameter of the body by 30-60 mm, at an angle of 60 degrees, the smoke guide element is made in the form of a hollow truncated cone with a side surface having vertical corrugation, fixed with pins into grooves on the inner surface of the upper part of the housing, while the bottom of the smoke guide element is located 10-15 mm below the slot holes of the housing, the dust collector is made in the form of a hollow cylinder, fixed with pins into grooves on the inner surface of the lower part of the housing, with a diameter smaller than the diameter of the internal smoke guide element by 20-40 mm, while the top of the dust collector is located above the bottom of the internal smoke guide element by at least 5 mm, the upper end of the lower part of the housing is designed to cover the slot holes in an intermediate working position and with the ability to cover slotted and additional rectangular holes in the transport position.

The disadvantage of this solution is the low efficiency of collecting small dust particles, which leads to an increase in the frequency of false alarms when dust penetrates into the smoke chamber.

The technical result of the invention is to increase the efficiency of the detector in enclosed spaces with a high dust content by improving the quality of filtration of air penetrating into the housing through slot holes and increasing the overhaul period of the detector. As well as expanding the arsenal of optical-electronic smoke detectors for fire alarms with scattered light.

The technical result is achieved by an optical-electronic fire smoke detector containing a socket with fastening, a plastic case with slotted holes in the upper part of the side cylindrical surface of the case and with a base, a board, an indicator, an optical module, a protective mesh, a dust collector, a smoke guide element in the form of a hollow cylinder, secured with pins into grooves to the lower internal part of the socket, the bottom of the smoke guide element is located below the slot openings of the housing.

What is new is that, additionally, on the base of the housing and coaxially with the housing, a cylindrical casing is installed in the form of an inverted glass, fixed motionless on the outside with stops made on the base of the housing; on the upper base of the casing, a lower smoke guide element is rigidly installed, made in the form of an inverted truncated cone, angle between the generatrix of the cone of the lower smoke guide element and the base of the casing is equal to 45°, the truncated cone is made with a height that ensures that the base of the truncated cone is placed between the upper smoke guide element and a protective mesh in the form of a hollow cylinder without bases, made of nylon with a cell of 0.3x0.8 mm and installed the upper base is in the grooves on the lower inner part of the socket, and the lower base is in the grooves on the upper base of the cylindrical casing, on the outer surface of the base of the casing, limited by the lower end of the lower smoke guide element, the edges of the dust collector are made, on the side surface of the casing and on the base of the casing between the smoke guide element and holes are made with grooves for the nylon mesh; inside the casing there is a metal mesh with a 1x1 mm cell in the shape of a hollow cylinder without bases, rigidly connected to the side surface.

In fig. Figure 1 shows a diagram of an optical-electronic fire smoke detector.

The optical-electronic smoke detector contains a socket 1 with fastening 2, a plastic housing 3 with slotted holes 4 in the upper part of the side cylindrical surface of the housing 3 and with the base of the housing, a board 5, an indicator 6, an optical module 7, a protective mesh 8, a dust collector 9, smoke guide element 10 in the form of a hollow cylinder, secured with pins 11 in grooves 12 to the lower inner part of the socket 1, the bottom of the smoke guide element 10 is located below the slot holes 4 of the housing 3.

A cylindrical casing 13 in the form of an inverted glass is installed on the base of the housing 3 and coaxially with the housing. The casing 13 is fixed motionless on the outside by stops 14 made on the base of the casing 3. The diameter of the casing is 100 mm, the height is 12 mm. On the upper base of the casing 13, a lower smoke guide element 15 is rigidly installed, located below the smoke guide element 10, made in the form of an inverted truncated cone, the angle between the generatrix of the cone of the lower smoke guide element 15 and the base of the casing 13 is 45°. The lower smoke guide element can be manufactured together with the casing 13 as a single element. The truncated cone of the lower smoke guide element 15 is made at a height that ensures that the upper base of the truncated cone 15 is placed between the lower end of the upper smoke guide element 10 and the protective mesh 8. The protective mesh 8 is placed at a distance of 5 mm from the side surface of the housing 3. The protective mesh 8 is made in the form of a hollow cylinder without bases made of nylon with a cell of 0.3x0.8 mm and a height of 30 mm. The upper and lower base of the mesh are rigidly connected to the plastic rim. The protective mesh 8 is installed with an upper base with a rim in grooves 16 on the lower inner part of the socket, and a lower base with a rim in grooves 17 on the upper base of a cylindrical casing 13. The dust collector 9 for fine dust penetrating through the mesh is made in the form of edges on the outer surface of the base casing 13, limited by the lower end of the lower smoke guide element 15. On the side surface of the casing 13, side holes 18 are made, and on the base of the casing 13, between the lower smoke guide element 15 and the grooves 17 for the nylon mesh 8, holes 19 are made, ensuring free passage of air into the optical module 7 The side holes are placed evenly and are made in the form of rectangles measuring 10x5 mm in the amount of 20-24 pieces. The holes on the upper base of the casing are placed evenly and are made in the form of a sector of a ring with a width of 8 mm, an outer arc length of 10 mm, in the amount of 20-24 pieces. Inside the casing 13 there is a metal mesh 20 with a 1x1 mm cell in the form of a hollow cylinder without bases, rigidly connected to the side surface of the casing 13.

The protective mesh 8 is placed opposite the slot holes 4 and, together with the metal mesh 20, forms a preliminary barrier for the penetration of dust and small insects into the inside of the housing and into the optical module. The design of the casing and smoke guide elements ensure the settling and retention of fine dust that has penetrated through the mesh between the edges of the dust collector by changing the direction of air flow.

The nylon fabric of the protective mesh - polyester has electrostatic properties, due to which the material attracts dust and additionally prevents its penetration into the optical module and false alarms. In this case, as the outer surface of the nylon mesh becomes clogged, the air flow will penetrate through the additional metal mesh inside the casing, then through the holes in the upper base of the casing and the lower smoke guide element.

The main components of the smoke sensor (housing, optical module), as in most analogues, are connected to each other with plastic latches, therefore they are not shown in the diagram.

The proposed design improves the efficiency of the detector in enclosed spaces with a high dust content by improving the quality of filtration of air penetrating into the housing through slot openings.

The sensor is assembled as follows.

The metal mesh 20 is placed inside the casing 13, which is installed on the lower inner surface of the housing 3 and is fixed with stops 14 on the outside. The upper smoke guide element 10 is attached to the lower inner part of the socket 1 using pins 11 in the grooves 12. The nylon protective mesh 8 is fixed in the grooves 16 and 17 when connecting the housing 3 and the socket 1.

The optical-electronic smoke sensor works as follows.

An optical module with labyrinth channels that prevent light from entering inside, including a light emitter with a light receiver, works similarly to most of those used, so the diagram is shown without detail. Pulse sequences of electrical signals generated by an electronic circuit on the board are converted by a light emitter into light pulses. Scattered radiation is received by a light receiver, which is optically inaccessible to direct radiation from a light emitter, the optical axis of which is located at an angle to the optical axis of the light receiver. The resulting scattered reflected radiation is converted by the light receiver into electrical signals, which are processed by elements of the electronic circuit of the board 5 with the subsequent formation of “Standby mode” signals or, in the presence of smoke aerosols, “Fire”.

Dust penetrating through slot holes 4 in the side surface of the housing is retained by mesh 8, and purified air or smoke freely penetrates into the optical module (air direction is shown by arrows A). In this case, especially small dust particles that have passed through the mesh, thanks to the presence of the upper smoke guide element 10, settle and are retained between the edges of the dust collector 9 due to a change in the direction of the air flow.

During operation of the sensor, as the outer side of the nylon mesh 8 becomes clogged with dust, air enters the housing 13 through the metal mesh 20, which retains some of the dust, then through holes 18 and 19 it is directed to the optical module 7 (the direction of the air is shown by arrows B). In this case, the lower smoke guide element 15 directs air to the inner surface of the nylon mesh 8, which has electrostatic properties, due to which part of the dust is attracted and retained on the inner side of the nylon mesh. Thanks to the presence of the upper smoke guide element, the remaining small dust particles settle and are retained between the edges by changing the direction of the air flow.

Thus, the proposed optical-electronic smoke fire detector has high protection against false alarms while ensuring the reliability of the detector in the event of a fire, and the overhaul period of the detector is increased by at least 2 times. The arsenal of technical equipment related to optical-electronic smoke detectors is also expanding.

Claims (1)

An optical-electronic fire smoke detector containing a socket with fastening, a plastic case with slotted holes in the upper part of the side cylindrical surface of the case and with a base, a board, an indicator, an optical module, a protective mesh, a dust collector, a smoke guide element in the form of a hollow cylinder secured with pins into grooves to the lower inner part of the socket, the bottom of the smoke guide element is located below the slot holes of the housing, characterized in that additionally on the base of the housing and coaxially with the housing, a cylindrical casing is installed in the form of an inverted glass, fixed motionless on the outside with stops made on the base of the housing, on On the top base of the casing, a lower smoke guide element is rigidly installed, made in the form of an inverted truncated cone, the angle between the generatrix of the cone of the lower smoke guide element and the base of the casing is 45°, the truncated cone is made at a height that ensures the placement of the base of the truncated cone between the upper smoke guide element and the protective mesh in the form of a hollow cylinder without bases, made of nylon with a cell of 0.3×0.8 mm and installed with the upper base in grooves on the lower inner part of the socket, and the lower base in grooves on the upper base of the cylindrical casing, on the outer surface of the casing base, limited by the lower end of the lower smoke guide element, the edges of the dust collector are made, holes are made on the side surface of the casing and on the base of the casing between the smoke guide element and the grooves for the nylon mesh, inside the casing there is a metal mesh with a cell of 1×1 mm in the shape of a hollow cylinder without bases, rigidly connected to the side surface.