RU2800978C1 - Optical-electronic fire sensor - Google Patents

Abstract

FIELD: fire alarms.

SUBSTANCE: optical-electronic fire detector contains an insert with a fastener fixed in the cap, a housing with a base, an optical module, a smoke guide element made inside the housing in the form of a disk parallel to the base. Slots are located on the side surface of the cylindrical housing below the optical module. Inside the body, above the slots, two smoke guide elements are installed, placed parallel to the base of the body and one above the other, the first smoke guide element is made in the form of a ring with an outer diameter equal to the inner diameter of the body, the second smoke guide element is located above the first smoke guide element and is made in the form of a disc with an outer diameter equal to the inner diameter of the housing, the smoke guide elements are interconnected with the formation of a free space between them, providing a reversal of the air flow, the inner surface of the base is made with vertical partitions that ensure dust settling.

EFFECT: improved protection against false alarms in case of disturbing influences in the form of a sharp horizontal air flow, direct ingress of smoke into the housing and the smoke chamber.

1 cl, 1 dwg

Description

The invention relates to the field of fire alarms, namely to optical-electronic smoke detectors of a fire alarm with diffused light, which are designed to detect a fire accompanied by the appearance of smoke in enclosed spaces, including in conditions of a sharp air flow (draught, turning on ventilation, opening doors, windows, etc.).

A smoke chamber is known for an optical-electronic smoke detector containing a socket and a sensor, which is a plastic case with slotted holes, inside which an opto-electronic system and a board with radio elements are placed, and a protective mesh with a mesh size is installed on the outside of the smoke chamber on the cover 1×1 mm (utility model patent RU No. 85716, published on August 10, 2009).

The disadvantage of this solution is that the protective mesh, as it becomes clogged with dust and other suspended particles (debris), creates additional resistance to air flow, which 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.

Known housing ceiling fire smoke detector for a horizontally ventilated smoke chamber (patent RU No. 2231238, publ. 20.06.2004). The housing is formed by side and end walls with the possibility of installing a smoke chamber in its central region so that its openings for the passage of smoke are located opposite the side wall of the housing. The housing is equipped with vertical partitions dividing the housing into sections of horizontal and vertical passage of smoke. In sections of the horizontal passage of smoke, holes are made in the side wall of the housing. In sections of the vertical passage of smoke, holes are made in the end walls of the housing and curvilinear channels are formed to ensure the passage of smoke from the holes in the end walls of the housing to the openings of the smoke chamber.

The design of the housing provides a direct, rapid flow of smoke into a horizontally ventilated smoke chamber, regardless of the direction of its distribution, including from the interceiling space, by reducing the aerodynamic resistance to the flow of smoke.

The disadvantage of this housing is the low efficiency of operation in conditions of a sharp air flow (draft, turning on ventilation, opening a door, window, etc.), which can entrain dust accumulated inside the detector housing into the smoke chamber and cause a false alarm of the detector.

A known smoke fire detector with a horizontally ventilated smoke chamber containing a socket with a mount, a plastic housing with slotted holes in the side of the housing, a board, an indicator, an optical module (optoelectronic smoke detector IP 212-45, Passport 4371-006-12215496- 00 PS). The detector body consists of two parts: base and cover. The lower part of the cover is made in the form of a truncated cone with a concave side surface. This concave surface has slotted openings for smoke to enter both from the side and from below. When smoke enters the housing from the bottom up, the directional flow is destroyed due to aerodynamic resistance to a change in the direction of smoke propagation, which reduces the rate of filling the chamber with smoke, and reduces the response time of the detector. The practical application of fire smoke detectors of this housing design 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, on the slotted holes. 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, which reduces the quality of the detector.

Known smoke fire detector containing a socket with a mount, a cylindrical plastic case with slotted holes in the side of the case, a solid surface of the inner corrugated part of the base of the case, a board, an indicator, an optical module, a smoke guide element (patent RU No. 211299, publ. 30.05.2022 ). The housing is made of composite, the upper and lower parts of the side surface of the housing are interconnected by a threaded connection, the slotted holes are placed on the side surface of the upper part of the housing, while on the upper part of the housing below the filtration holes there is an external thread, and on the upper end of the lower part of the housing an internal thread is made , in the working position, the side surface of the lower part of the housing is located below the slotted holes on the side surface of the upper part of the housing, the upper end of the lower part of the housing is made with the possibility of overlapping the slotted holes in the transport position, on the outer surface of the upper part of the housing, a stop shoulder is made around the circumference above the slotted holes, providing emphasis on the lower part of the body when fully tightened. The smoke guide element is located on the inner surface of the upper part of the housing above the slot holes, is made in the form of a truncated cone without bases, with a height equal to the height of the slot holes, and is fixed with pins in the grooves on the inner surface of the upper part of the housing.

The disadvantage of the sensor is low efficiency due to the location of the slotted holes on the upper part of the side surface of the housing, which increases the risk of both direct entry, accumulation of dust, insects inside the detector housing in the smoke chamber and the occurrence of false alarms, and a decrease in the proportion of smoke entering the smoke chamber in conditions of a sharp air flow (draft, turning on the ventilation, opening a door, window, etc.), and the smoke guide element and the dust collector do not provide sufficient protection against dust ingress into the optical module (smoke chamber) and the sensor is triggered with predominantly horizontal distribution of smoke flows.

The closest in technical essence is an optical-electronic smoke sensor for conditions complicated by the presence of suspended particles of cement inside the room, containing 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 (patent RU No. 210429, published on April 15, 2022). 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.

The disadvantage of the sensor is its low efficiency due to the location of the slotted holes on the base of the housing, which increases the time for smoke to enter the optical module (smoke chamber) and the sensor to operate with predominantly horizontal distribution of smoke flows. At the same time, the smoke guide element and the dust collector do not provide sufficient protection against false alarms in conditions of sudden air flow.

The technical result of the optoelectronic fire sensor is to increase the efficiency of the sensor by improving the quality of protection against false alarms, including in the event of a sharp horizontal air flow, while ensuring direct smoke into the housing and smoke chamber, expanding the technical means of fire optical electronic sensors with high reliability in case of fire.

The technical result is achieved by an optical-electronic fire detector, containing an insert with a mount fixed in the base, a housing with a base, an optical module, a smoke guide element made inside the housing in the form of a disk parallel to the base.

What is new is that the slotted holes are located on the side surface of the cylindrical housing below the optical module, inside the housing above the slotted holes there are two smoke guide elements placed parallel one above the other and together with the base of the housing, the first smoke guide element is made in the form of a ring with an outer diameter equal to the inner the diameter of the housing rigidly connected by the lower surface of the ring with vertical guides providing emphasis on the base of the housing, the second smoke guide element is located above the first smoke guide element and is made in the form of a disk with an outer diameter equal to the inner diameter of the housing, the disk is coaxially mounted on a cylinder located in the center of the housing base , connected to the base of the housing and the lower surface of the disk through the grooves with pins, the smoke guide elements are connected to each other using pins and grooves, with the formation of a free space between the smoke guide elements, providing a reversal of the air flow, and the inner diameter of the ring is larger than the diameter of the cylinder, providing a reversal of the air flow with dust settling, the inner surface of the base is made with vertical partitions that ensure dust settling.

In FIG. 1 shows a diagram of a fire optoelectronic sensor.

Optoelectronic fire sensor, contains an insert 1 (Fig. 1) with a mount 2, fixed in the base (not shown in the figure), a housing 3 with slotted holes 4 and a base 5, an optical module 6, a smoke guide element 7, made inside the housing 3 in the form of a disk parallel to the base 5.

The slot holes 4 are located on the side surface of the cylindrical body 3 below the optical module 6. Inside the body, above the slot holes, two smoke guide elements 7, 8 are installed, placed parallel one above the other and together with the base of the case 5. The first smoke guide element 8 is made in the form of a ring with an internal a round hole 9 in the center and with an outer diameter equal to the inner diameter of the housing 3, rigidly connected by the lower surface of the ring 8 with vertical guides 10 in the form of rectangles, ensuring that the ring 8 rests on the base 5 of the housing 3. The second smoke guide element 7 is placed above the first smoke guide element 8 and made in the form of a disc with an outer diameter equal to the inner diameter of the housing 3. The disk 7 is coaxially mounted on the cylinder 11, placed in the center of the base 5 of the housing 3, connected to the base 5 of the housing 3 and the lower surface of the disk 7 through the grooves 12 with pins 13. Smoke guide elements 7, 8 are connected to each other by means of pins 14 and grooves 15, with the formation of a free space between the smoke guide elements 7, 8 with the formation of a free space between the smoke guide elements 7, 8, providing a reversal of the air flow. The inner diameter of the ring 8 is made larger than the diameter of the cylinder 11, which ensures the reversal of the air flow with the deposition of dust. The inner surface of the base 5 is made with vertical partitions 16 placed parallel to each other between the vertical guides 10 and, for example, at an angle of 45° relative to the guides 10 in the form of segments or in the form of chords (the author does not claim the shape of the vertical partitions 16, but to improve efficiency dust retention, their number should be maximum), performing the function of a dust collector with the settling of dust that has fallen into the inside of the case with air and smoke, into the space between the partitions 16, excluding dust circulation in the event of a sharp air flow (draft).

On the upper surface of the base 5 there are vertical partitions 16.

Slotted holes 4 are located on the side surface of the cylindrical body 3 below the optical module 6 and below the smoke guide elements 7, 8, but above the vertical partitions 16 on the base 5. This arrangement of the slotted holes ensures the flow of air and smoke into the sensor housing between the smoke guide elements.

The main components of the smoke sensor (insert, housing, optical module), as in most analogues, are interconnected by plastic latches, therefore they are not shown in the diagram.

The sensor is assembled as follows.

A solid plastic cylinder 11 is fixed on the base 5 using the groove 12 of the pin 13 and the first smoke guide element 8 is installed. The smoke guide element 8 is a disk with a round hole 9 in the center and four vertical guides 10 in the form of rectangles resting on the base 5 of the body 3. A disk with a hole 9 and guides 10 are a single plastic construction. Since the outer diameter of the disc is equal to the inner diameter of the housing, the disk fits snugly against the inner surface of the housing, there is no need for additional connection. The second smoke guide element 7 is centrally mounted on the cylinder 11 and connected to the base 5 and the cylinder 11 through the grooves 12 using pins 13 installed on the base 5 and in the center of the lower part of the smoke guide element 8, respectively, and is attached to the first smoke guide element 8 with pins 14 located on the lower surface of the smoke guide element 7, and grooves 15 made on the upper surface of the smoke guide element 8.

The vertical guides 10 and the disk - smoke guide element 8 are a single element, the partitions 16 and the base 5 are also a single element. The height of the partitions 16 is 5 mm, the width and distance between the partitions 16 is 2 mm. The component parts of the body and the base are fastened together by latches (not shown in the diagram).

Optoelectronic fire sensor operates as follows.

The design of the case 3 of the optoelectronic fire sensor and smoke guide elements 7 and 8 provide free flow of smoke (air) through the holes, guides 10 and smoke guide elements 7 and 8 provide a change in the direction of the smoke (air) flow inside the case 3, when the direction of movement of suspended particles changes dust under the action of gravity, it is deposited due to the high specific gravity on the inner base 5 between the partitions 16, which are the dust collector.

At the same time, due to the double change in the direction of the air flow by 180 degrees and the settling of dust in the gaps between the partitions 16, it is ensured that dust does not enter the optical module even in the event of a sharp air flow (draft, turning on ventilation, opening a door, window, etc.).

When signs of smoke appear, the smoke, which has a higher temperature, freely rises inside the sensor housing and enters the optical module. An optical module with labyrinth channels, including a light source with a light receiver, operates 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 the board are converted by the light source into light pulses. Scattered radiation is received by a light detector, which is optically inaccessible to direct radiation of a 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 with the subsequent formation of the “Standby mode” signals or, in the presence of smoke aerosols, “Fire”.

Thus, the optical-electronic fire detector has high efficiency by improving the quality of protection against false alarms, including in conditions of a sharp air flow, while ensuring direct smoke into the housing and smoke chamber, and provides for the expansion of technical means of fire optoelectronic sensors with high reliability in case of fire.

Claims (1)

Optoelectronic fire sensor, containing an insert with a mount fixed in the base, a housing with a base, an optical module, a smoke guide element made inside the housing in the form of a disk parallel to the base, characterized in that the slotted holes are located on the side surface of the cylindrical housing below the optical module , two smoke guide elements are installed inside the body above the slotted holes, placed parallel one above the other and together with the base of the body, the first smoke guide element is made in the form of a ring with an outer diameter equal to the inner diameter of the body, rigidly connected by the lower surface of the ring with vertical guides, providing emphasis on the base of the body , the second smoke guide element is located above the first smoke guide element and is made in the form of a disk with an outer diameter less than the inner diameter of the housing, the disk is coaxially mounted on a cylinder located in the center of the housing base, connected to the housing base and the lower surface of the disk through grooves with pins, the smoke guide elements are connected between itself with the help of pins and grooves, with the formation of a free space between the smoke guide elements, providing a reversal of the air flow, and the inner diameter of the ring is made larger than the diameter of the cylinder, providing a reversal of the air flow with dust settling, the inner surface of the base is made with vertical partitions, providing dust settling.