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Aspirating smoke detection system in the tobacco warehouse and workshop applications (1. Kunming Hua Engineering Technology Limited liability company 2. Hongta Group Yuxi Cigarette Factory Security Fire Division / Feeds Author / Ning Weiguo 1, Sophie Li 1; Unclassified 2) 2.2 IR On the radio-type smoke detectors Traditional point-device protection against large space can not meet the provisions of relevant state laws and regulations, many manufacturers began to consider R & D with infrared detection system. With infrared systems operating principle is: when the transmitter and the receiver of its own between the infrared blocked by smoke when the receiver the received light intensity decay occurs, Alarm To judge the presence of smoke and an alarm signal. It is not suitable for more advanced fire detection and alarm products in large space of the last century, introduced 90 years. Smoke alarm with infrared equipment to some extent, although the detection equipment solved the legal problems mounting height, often used in place of large space holding frame, but in practice, the same can not overcome the many disadvantages. Reflection infrared beam detection system works diagram 2.2.1 found that fire late, with no improvement compared to point detectors. Infrared fire detection system in actual use, in order to ensure the realization of its detection capabilities, requires infrared transmitter and the receiver had no shelter. This requires that the warehouse shelves, goods, operating machinery (such as driving) are not allowed to install or move it to between transmitter and receiver, otherwise it will cause false positives. Therefore, the system installation process, in order to avoid these factors can induce false positives, equipment mostly installed in the workshop, warehouse and other large space in the ceiling. It will face the traditional alarm device is the same problem --- the smoke to reach a long distance, during the disturbance and so easy to dilution caused alarm late to detect vulnerable to a variety of factors. With infrared detectors and also because the sun roof of the thermal barrier effect of irradiation (see "Fire Alarm System Design Specification" [5] GB50116-98 of the 8.1.11 section below), it is difficult to grasp proper installation height, probe effect further affected. Fire, the hot smoke and air barrier in the road leading to the formation of barrier detector, especially with the metal roof of the warehouse, so that smoke started in the heat barrier layer below. In winter, the cooling effect also prevent the spread of smoke. Therefore, the smoke stratification may cause problems probe blind detectors with the same point there is no effective solution. 2.2.2 Alarm low sensitivity. Do not have the fire smoldering with no visible smoke or smoke only a little ability to stage early detection of fire. With infrared detection system alarm sensitivity is generally 30-50% less light ratio (see common Siemens, Panasonic, System Sensor product technical information on the fire detector), individual laser detection system with infrared sensitivity of up to 20% extinction rate (such as Universal Electric GS9108), or even smoke than the 3-5% point rate reduction of light sensitivity is poor, which further exacerbated because the large space to install a high degree of reaction caused by slow high, found in fire later. This is a high value on the protection of general warehousing, production sites of the tobacco companies is undoubtedly a very grave disadvantage. In the engineering practice, usually only by using special infrared rays to test the fire alarm detection system, with simulated fire, smoke and rarely tested, is difficult to achieve because of the smoke alarm required concentration, or to artificial security release enough smoke to achieve the required concentration is very safe alarm. Because already in use more high-value large space flammable Environment To simulate a large number of fire smoke test produced high risk. Thus, in a sense, with infrared detection system at the expense of detection sensitivity in exchange for a large space with high mounting height applications, is the time for space (alarm delay for large space applications), was quite upset and under the condition of . 2.2.3 easy to produce false positives and failure. System with infrared detection method used, it is easy to accidentally move to its launch and receiver objects between the trigger false positives. This workshop, storage and application sites easily happen: for example, forklift trucks loaded with goods entered the smoke bank birds, operating result of dust, sunlight interference. And with infrared systems are often difficult because the mounting bracket of the deformation, a small wall deformation, vibration caused by traffic running beam offset by the amount of light dropped qualifying failure, need for time consuming re-calibration. 2.2.4 maintenance difficulties. As with infrared systems, to avoid all kinds of block, so the installation location will be relatively high, particularly in the elevated bank, the installation is complete, in the absence of dedicated facilities, the premise, it is difficult for the installation of equipment in high maintenance and maintenance. Smoke high on the wall with infrared database maintenance needs 12 meters ladder, 4 together before competent, and often requires manufacturers with technical staff to re-calibrate the beam, sealed during the staff can not enter the insecticide, so maintenance is a dangerous word and time-consuming effort. 2.2.5 install the application difficult. In practical applications, the tobacco library with infrared smoke detector will be exposed to corrosive gases under to solve this problem, the detector needs to be installed in the "seal" the yard to achieve anti-corrosion cover. Nevertheless, the connector, cable, or will some still being exposed to corrosive gases, so the need to take the pipe wall and sealing joints, access holes, epoxy resin, glass, sealing, etc. One has to spend. The wall of the high-altitude operation is relatively difficult to use the PVC pipe is difficult to withstand wind and sun line aging, brittle fracture needs to be replaced after a few years. If you use the high cost of galvanized steel and easy to appear in three years after the rain corrosion rust. Past experience has told us that this complex "corrosion resistant" technology will always be some places an "oversight", resulting in corrosion of probe or line connector failure. On the other hand, libraries are often located in high smoke thunderstorms on the slopes or ridges, to avoid pesticides in outdoor alignment will face difficult fire-fighting equipment Lightning Problem, resulting in year after year, summer, often with infrared smoke detection system being struck by lightning paralysis reincarnation, virtually increase the number of maintenance and management costs. 2.3 Fire Alarm System Image As technology advances, new fire detection technology has been used in cigarette production, storage and other enterprises, one of them the image of fire alarm systems in these applications have a certain representation, and also many of the domestic tobacco enterprises have been some applications. Fire alarm system is divided into image I am an expert from leatherdigitalwatch.com, while we provides the quality product, such as digital diving watches Manufacturer , China digital display watches, leather wrist watches,and more.
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