A transport belt fire early warning method based on belt modification

Abstract

The present invention relates to the field of coal mine safety, and specifically to a fire early warning method for transport belts based on belt modification. The method first partially modifies the polyvinyl chloride (PVC) in the belt and grafts it with a temperature-sensitive material that is easily thermally decomposed. The PVC grafted with the temperature-sensitive material, conventional PVC, nitrile rubber, and carbon black additive are then mixed and vulcanized to form upper and lower covering layers of the belt. This results in a belt containing the temperature-sensitive material. The belt is then used in mine tunnel transportation. When the belt's temperature rises to the pyrolysis temperature of the temperature-sensitive material due to abnormal friction, different temperature-sensitive materials release different characteristic gases. A gas detector monitors changes in gas concentration and generation rate, transmits the signal to a data processor, and uses a warning model to determine the development of the belt fire and issue different warning messages. The present invention can effectively monitor underground coal mine transport belts, promptly detecting abnormalities in belt operation and thus avoiding potential fire accidents.

Description

Technical Field

[0001] The present invention relates to the field of coal mine safety, and in particular to a transport belt fire early warning method based on belt modification. Background Art

[0002] Among external fire accidents in coal mines, fires caused by conveyor belt fires account for the vast majority. Belt fires are categorized into two types based on their causes: fires caused by belt friction and fires caused by non-belt friction. The former primarily arises from belt jams, which cause the active pulley to completely slip, leading to friction between the belt and the pulley, or fires caused by mechanical failures of the conveyor's pulleys or idlers, leading to high-speed friction between the belt and the conveyor belt. The latter primarily arises from belt conveyor electrical equipment failures, which overheat the equipment in a short period of time, leading to belt fires, or fires caused by spontaneous combustion of coal on the belt, which ignites the belt.

[0003] Currently, my country primarily uses CO sensors, smoke sensors, and temperature sensors for belt fire monitoring and early warning. However, temperature sensors, affected by their installation location, cannot accurately predict belt fires. Low-temperature oxidation of coal also produces CO, making CO detection inaccurate for belt fire warnings. Smoke detection often issues an alarm because the belt has already entered the initial combustion phase. Therefore, these methods cannot accurately warn of belt fires. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a fire warning method for transport belts based on belt modification. By chemically modifying the transport belts and grafting temperature-sensitive materials onto the belt cover, a special gas detector is used to monitor and transmit signals of the gases and gas concentrations generated by the temperature-sensitive materials when heated. This effectively improves the safety level of production in mine tunnels and protects the lives of workers. The technical solutions adopted are:

[0005] A transport belt fire early warning method based on belt modification, comprising the following steps:

[0006] (1) reacting polyvinyl chloride with a temperature-sensitive material at a temperature below 60° C., grafting the temperature-sensitive material that is easily thermally decomposed onto the polyvinyl chloride to obtain polyvinyl chloride containing the temperature-sensitive material;

[0007] (2) adding 1 part of polyvinyl chloride grafted with the temperature-sensitive material in step (1), 29 parts of conventional polyvinyl chloride, 30 parts of nitrile rubber, and 30 parts of carbon black additive to a mixer, and then conveying the mixed material to a low-temperature vulcanizer for vulcanization at a temperature below 70° C.;

[0008] (3) using the material prepared in step (2) to prepare upper and lower covering layers of a belt to obtain a belt containing a temperature-sensitive material;

[0009] (4) The belt prepared in step (3) is used for transportation in a mine tunnel. Several characteristic gas detectors, a data receiver and processor with an internal early warning model, a regional alarm device and a regional display are also installed in the tunnel. When the belt is abnormally heated, the temperature-sensitive material generates characteristic gas. The characteristic gas and the concentration change pattern of the generated gas are monitored by the characteristic gas detector. A graded early warning of the belt fire is generated based on the early warning model in the data receiver and processor, and the early warning information is transmitted to the mine control room and on-site staff using the regional alarm device and the regional display.

[0010] Preferably, the temperature-sensitive material is a substance that can produce special gases that do not exist in mines at low temperatures.

[0011] As a further preference, the temperature-sensitive material is a short-chain chlorinated paraffin, or a chlorinated paraffin-like material.

[0012] Preferably, in step (1), the amount of the temperature-sensitive material added is 0.1%-1% of the polyvinyl chloride.

[0013] Preferably, the characteristic gas detectors are connected in parallel, and each is equipped with a different code.

[0014] Preferably, the characteristic gas detectors are arranged at intervals of 30-50 meters; each characteristic gas detector can detect the gas generated by the thermal decomposition of temperature-sensitive materials and its concentration changes, and is respectively installed on the leeward side of the air inlet of the mine tunnel, and is vertically suspended at intervals from the top of the machine head along the air inlet direction at a distance of 0.3 meters from the tunnel top and 0.2 meters from the tunnel side wall in a straight line.

[0015] Preferably, the early warning model is determined based on the decomposition temperature of the temperature-sensitive material, the types and concentration changes of different gases generated by the belt when heated, and is divided into three early warning levels, namely: the first level, the CO2 / CO ratio is detected to be 3, and the temperature range is 90-110°C; the second level, hydrogen chloride and C2H4 are detected on the basis of the first level, and the temperature range is 110-150°C; the third level, rapid growth of C2H4 or smoke is detected on the basis of the first and second levels, and the temperature range is above 150°C.

[0016] Preferably, the data receiver and processor processes the data transmitted from the characteristic gas detector based on the internal early warning model, determines the level of the belt fire, and transmits the alarm information to the regional alarm device and regional display.

[0017] Preferably, after receiving the transmitted alarm information, the regional alarm device can display the corresponding belt temperature and gas concentration information, and transmit the early warning information to the mine central control system; the regional display is connected to the regional alarm device, and the regional display can display the characteristic gas detector code that detects the characteristic gas.

[0018] Preferably, in the method for early warning of belt fire, a bus isolator is provided between the power bus for connection and the signal bus for transmission, and a fire protection module is also provided on the signal bus.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention provides a belt-modified conveyor belt fire early warning method. By chemically modifying the conveyor belt and grafting a temperature-sensitive material onto the belt's covering, the uniform mixing of the temperature-sensitive material and the belt covering allows the material in the belt to immediately release gas when the belt temperature rises, resulting in earlier belt fire warnings and higher prediction accuracy. This method can provide an effective way to accurately determine the fire source and fire development in mine belt fires, thereby reducing the likelihood of belt fires caused by abnormal belt operation and significantly improving mine safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flow chart of the present invention;

[0022] Figure 2 This is a structural diagram of the belt of the present invention applied in a mine.

[0023] In the figure: 1. Belt; 2. Characteristic gas detector; 3. Data receiver and processor; 4. Area alarm device; 5. Area display; 6. Fire protection module; 7. Bus isolator; 8. Power bus; 9. Signal bus. DETAILED DESCRIPTION

[0024] The accompanying drawings are for illustrative purposes only; it should be understood that the cases mentioned below are only used to explain the present invention, in order to facilitate the description of the present invention and simplify the description, and therefore, should not be understood as limiting the present invention.

[0025] The principles and features of the present invention are described below in conjunction with the examples. The examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Where specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0026] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0027] Example 1

[0028] Implementation background: A mine plans to install a conveyor belt with a required transport capacity of 1200t / h. It uses a 4*200kw main motor as the drive device. The conveyor belt has a width of 1200mm and a strength of 1000kN / mm. It plans to use the method of grafting a belt to modify a temperature-sensitive material in the present invention to prepare the belt and apply the belt to a conveyor belt fire warning system. The specific steps are as follows:

[0029] like Figure 1 As shown, the cover layer components of the PVG1250S transport belt used in this tunnel are improved, and thermoplastic elastomer is selected as the rubber of the cover layer.

[0030] A transport belt fire early warning method based on belt modification, comprising the following steps:

[0031] (1) Polyvinyl chloride is reacted with a temperature-sensitive material at a temperature below 60° C., and chlorinated paraffin that is easily thermally decomposed is grafted onto the polyvinyl chloride to obtain polyvinyl chloride containing chlorinated paraffin; the amount of chlorinated paraffin added is 0.2% of the polyvinyl chloride.

[0032] (2) 1 part of polyvinyl chloride grafted with the temperature-sensitive material in step (1), 29 parts of conventional polyvinyl chloride, 30 parts of nitrile rubber, and 30 parts of carbon black additive are added to a mixer, and then the mixed material is transported to a low-temperature vulcanizer for vulcanization at a temperature below 70°C.

[0033] (3) The material prepared in step (2) is used to prepare the upper and lower covering layers of the belt to obtain a chemically modified belt containing a temperature-sensitive material.

[0034] (4) The belt prepared in step (3) is used for transportation in mine tunnels. Figure 2 As shown, several characteristic gas detectors 2, a data receiver and processor 3 with an internal early warning model, an area alarm device 4 and an area display 5 are also installed in the tunnel. When the belt heats up abnormally, the temperature-sensitive material generates characteristic gas. The characteristic gas and the concentration change pattern of the generated gas are monitored by the characteristic gas detector 2. Based on the early warning model in the data receiver and processor 3, a graded early warning of the belt fire is formed, and the early warning information is transmitted to the mine control room and on-site staff using the area alarm device 4 and the area display 5.

[0035] As a further preferred design, the characteristic gas detectors 2 are connected in parallel, each with a different code. The characteristic gas detectors 2 are installed every 30 meters, capable of detecting gases generated by the thermal decomposition of temperature-sensitive materials and changes in their concentrations. They are installed on the downwind side of the mine tunnel's air intake, suspended vertically from above the head of the detector along the air intake direction, at intervals of 0.3 meters from the tunnel roof and 0.2 meters from the tunnel sidewall.

[0036] As a further preferred design, the early warning model is determined based on the decomposition temperature of the temperature-sensitive material and the types and concentration changes of different gases generated by the belt when heated, and is divided into three early warning levels, namely: the first level, the CO2 / CO ratio is detected to be 3, and the temperature range is 90-110°C; the second level, hydrogen chloride and C2H4 are detected on the basis of the first level, and the temperature range is 110-150°C; the third level, rapid growth of C2H4 or smoke is detected on the basis of the first and second levels, and the temperature range is above 150°C.

[0037] The data receiver and processor 3 processes the data transmitted by the characteristic gas detector based on its internal warning model, determines the severity of the belt fire, and transmits the alarm information to the regional alarm device 4 and regional display 5. After receiving the alarm information, the regional alarm device 4 displays the corresponding belt temperature and gas concentration information and transmits the warning information to the mine's central control system. The regional display 5 is connected to the regional alarm device and displays the characteristic gas detector code that detected the characteristic gas, thereby accurately identifying the belt location where the abnormality occurred.

[0038] For safety in the mine tunnels, a fire protection module 6 is also provided on the signal bus 9 under the mine tunnels, which is connected to the mine central control system for input, output and feedback signals; a bus isolator 7 is provided between the power bus 8 and the signal bus 9 to avoid crossing and overlapping of the lines.

[0039] The working process is as follows:

[0040] When belt 1 experiences abnormal operating conditions, causing the belt to heat up, the temperature-sensitive material in belt 1 decomposes due to the heat. At around 110°C, hydrogen chloride gas is released. The characteristic gas detector 2 detects the gas and changes in gas concentration, and transmits the data to the data acquisition and processing center. The built-in early warning model is then used to determine the occurrence and development of the belt fire, and different alarm levels are issued according to the actual situation, thereby ensuring mine safety.

[0041] Example 2

[0042] A transport belt fire early warning method based on belt modification, comprising the following steps:

[0043] (1) Polyvinyl chloride is reacted with a temperature-sensitive material at a temperature below 60° C., and chlorinated paraffin that is easily thermally decomposed is grafted onto the polyvinyl chloride to obtain polyvinyl chloride containing chlorinated paraffin; the amount of chlorinated paraffin added is 0.5% of the polyvinyl chloride.

[0044] (2) 1 part of polyvinyl chloride grafted with the temperature-sensitive material in step (1), 29 parts of conventional polyvinyl chloride, 30 parts of nitrile rubber, and 30 parts of carbon black additive are added to a mixer, and then the mixed material is transported to a low-temperature vulcanizer for vulcanization at a temperature below 70°C.

[0045] (3) The material prepared in step (2) is used to prepare the upper and lower covering layers of the belt to obtain a chemically modified belt containing a temperature-sensitive material.

[0046] (4) The belt prepared in step (3) is used for transportation in mine tunnels. Figure 2 As shown, several characteristic gas detectors 2, a data receiver and processor 3 with an internal early warning model, an area alarm device 4 and an area display 5 are also installed in the tunnel. When the belt heats up abnormally, the temperature-sensitive material generates characteristic gas. The characteristic gas and the concentration change pattern of the generated gas are monitored by the characteristic gas detector 2. Based on the early warning model in the data receiver and processor 3, a graded early warning of the belt fire is formed, and the early warning information is transmitted to the mine control room and on-site staff using the area alarm device 4 and the area display 5.

[0047] The characteristic gas detectors 2 are arranged at intervals of 50 meters. Other matters not mentioned are the same as those in Example 1.

[0048] Example 3

[0049] A transport belt fire early warning method based on belt modification, comprising the following steps:

[0050] (1) Polyvinyl chloride is reacted with a temperature-sensitive material at a temperature below 60° C., and chlorinated paraffin that is easily thermally decomposed is grafted onto the polyvinyl chloride to obtain polyvinyl chloride containing chlorinated paraffin; the amount of chlorinated paraffin added is 1% of the polyvinyl chloride.

[0051] (2) 1 part of polyvinyl chloride grafted with the temperature-sensitive material in step (1), 29 parts of conventional polyvinyl chloride, 30 parts of nitrile rubber, and 30 parts of carbon black additive are added to a mixer, and then the mixed material is transported to a low-temperature vulcanizer for vulcanization at a temperature below 70°C.

[0052] (3) The material prepared in step (2) is used to prepare the upper and lower covering layers of the belt to obtain a chemically modified belt containing a temperature-sensitive material.

[0053] (4) The belt prepared in step (3) is used for transportation in mine tunnels. Figure 2As shown, several characteristic gas detectors 2, a data receiver and processor 3 with an internal early warning model, an area alarm device 4 and an area display 5 are also installed in the tunnel. When the belt heats up abnormally, the temperature-sensitive material generates characteristic gas. The characteristic gas and the concentration change pattern of the generated gas are monitored by the characteristic gas detector 2. Based on the early warning model in the data receiver and processor 3, a graded early warning of the belt fire is formed, and the early warning information is transmitted to the mine control room and on-site staff using the area alarm device 4 and the area display 5.

[0054] The characteristic gas detectors 2 are arranged at intervals of 50 meters. Other matters not mentioned are the same as those in Example 1.

[0055] Those skilled in the art will appreciate that the experimental examples shown herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art may make various other variations based on the technical teachings disclosed herein without departing from the essence of the present invention, and such variations remain within the scope of protection of the present invention.

Claims

1. A fire warning method for a transport belt based on belt modification, characterized in that: The specific steps include: (1) reacting polyvinyl chloride with a temperature-sensitive material at a temperature below 60° C., grafting the temperature-sensitive material that is easily thermally decomposed onto the polyvinyl chloride to obtain polyvinyl chloride containing the temperature-sensitive material; the temperature-sensitive material is chlorinated paraffin; (2) 1 part of the polyvinyl chloride grafted with the temperature-sensitive material in step (1), 29 parts of conventional polyvinyl chloride, 30 parts of nitrile rubber, and 30 parts of carbon black additive are added to a mixer, and then the mixed material is conveyed to a low-temperature vulcanizer for vulcanization at a temperature below 70°C; (3) Using the material prepared in step (2) to prepare upper and lower covering layers of a belt to obtain a belt containing a temperature-sensitive material; (4) The belt prepared in step (3) is used for transportation in a mine tunnel. Several characteristic gas detectors, a data receiver and processor with an internal warning model, a regional alarm device, and a regional display are also installed in the tunnel. When the belt is abnormally heated, the temperature-sensitive material generates characteristic gas. The characteristic gas and the concentration change pattern of the generated gas are monitored by the characteristic gas detector. A graded warning of the belt fire is generated based on the warning model in the data receiver and processor, and the warning information is transmitted to the mine control room and on-site staff using the regional alarm device and the regional display; Wherein, each of the characteristic gas detectors is connected in parallel, and each is equipped with a different code; The warning model is determined based on the decomposition temperature of temperature-sensitive materials and the types and concentration changes of different gases generated by the belt when heated, and is divided into three warning levels: the first level, the CO2 / CO ratio is detected to be 3, and the temperature range is 90-110°C; the second level, hydrogen chloride is detected on the basis of the first level, and the temperature range is 110-150°C; the third level, smoke is detected on the basis of levels one and two, and the temperature range is above 150°C.

2. The method for early warning of fire of a transport belt based on belt modification according to claim 1, characterized in that: In the step (1), the amount of the temperature-sensitive material added is 0.1%-1% of the polyvinyl chloride.

3. The method for early warning of fire of a transport belt based on belt modification according to claim 1, characterized in that: The characteristic gas detectors are set up at intervals of 30-50 meters; each characteristic gas detector can detect the gas generated by the thermal decomposition of temperature-sensitive materials and its concentration changes, and are respectively installed on the leeward side of the air inlet of the mine tunnel, and are vertically suspended at intervals from the top of the machine head along the air inlet direction at a distance of 0.3 meters from the tunnel top and 0.2 meters from the tunnel side wall in a straight line.

4. The method for early warning of fire of a transport belt based on belt modification according to claim 1, characterized in that: The data receiver and processor processes the data transmitted from the characteristic gas detector based on the internal early warning model, determines the level of the belt fire, and transmits the alarm information to the regional alarm device and regional display.

5. The method for early warning of fire of a transport belt based on belt modification according to claim 1, characterized in that: After receiving the alarm information, the regional alarm device can display the corresponding belt temperature and gas concentration information, and transmit the early warning information to the mine central control system; the regional display is connected to the regional alarm device, and the regional display can display the characteristic gas detector code that detects the characteristic gas.

6. The method for early warning of fire of a conveyor belt based on belt modification according to claim 1, characterized in that: In the method for early warning of belt fire, a bus isolator is provided between a power bus for connection and a signal bus for transmission, and a fire protection module is also provided on the signal bus.

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