A mine material use process toxic gas detection system and detection method

Abstract

The application discloses a mine material use process toxic gas detection system and a detection method. In the system, a compressed air cylinder is connected with a gas supply pipeline in a room temperature thermostat, which is used for supplying gas to corresponding mechanisms in the box. A mixing mechanism is connected with an inlet of a reaction tank. The reaction tank is connected with an outlet pipeline for connecting a gas storage tank, and is provided with an equal concentration peristaltic valve. A piston movement mechanism is arranged in the gas storage tank, which is used for changing the volume of the gas storage tank. The gas storage tank is connected with a venting pipeline for connecting a gas chromatograph. The venting pipeline is provided with a gas taking valve and a gas taking peristaltic pump. The venting pipeline is also connected with an exhaust valve and an air inlet valve. A PLC controller is electrically connected with a pressure transmitter device for detecting the pressure of the reaction tank and the gas storage tank, the mixing mechanism, the piston movement mechanism, the room temperature thermostat and a computer. The application can intelligently control and detect the whole process of the test, effectively avoids experimental errors caused by manual reading, and has the advantages of simple operation and high data precision.

Description

Technical Field

[0001] This invention relates to the field of mining material testing, and in particular to a system and method for detecting toxic gases during the use of mining materials. Background Technology

[0002] Currently, during the use of mining materials, the materials themselves and their interaction with the environment (water, coal) can produce toxic gases. In recent years, due to the need for safe coal mine production, various mining materials have been invented and applied; however, there is no good performance testing scheme for systematically testing their performance. Currently, the testing of toxic gases from mining materials during use employs dispersed testing schemes or other thermogravimetric analyzers. These experimental systems lack specificity, resulting in problems such as complex testing methods, low accuracy, and slow speed. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a detection system and method for detecting toxic gases during the use of mining materials. This system can comprehensively detect toxic and harmful gases generated during the reaction process of mining materials, solving the problems of complex detection methods, low accuracy, and slow speed in the prior art.

[0004] This invention discloses a toxic gas detection system for the use of mining materials, comprising: a room temperature constant temperature chamber, a gas chromatograph, a compressed air cylinder, a computer and a PLC controller. The room temperature constant temperature chamber is equipped with: a reaction vessel, a reciprocating drive mechanism for the vessel acting on the reaction vessel, a mixing mechanism, the reaction vessel, and a variable volume gas storage tank.

[0005] The compressed air cylinder is connected to the air supply pipeline installed in the room temperature constant temperature chamber. The air supply pipeline is connected to the tank reciprocating drive mechanism and the mixing mechanism for supplying air.

[0006] The reaction vessel is equipped with a reaction cup. The mixing mechanism is connected to the inlet of the reaction vessel. The PLC controller is electrically connected to the mixing mechanism to mix different materials and inject the mixed material into the reaction cup. The reaction vessel is connected to an outlet pipe to connect to a gas storage tank. The outlet pipe is equipped with a filter, a concentration equalization peristaltic valve, and a screen.

[0007] The gas storage tank is equipped with a piston movement mechanism. The PLC controller is electrically connected to the piston movement mechanism to control the change of the volume inside the gas storage tank to adjust the pressure to the internal and external balance. The gas storage tank is connected to an emptying pipeline for connecting to a gas chromatograph. The emptying pipeline is equipped with a gas intake valve and a gas intake peristaltic pump. On the emptying pipeline, before the gas intake valve, there are an exhaust branch and an intake branch. The exhaust branch is equipped with an exhaust valve, and the intake branch is equipped with an intake valve.

[0008] The PLC controller is electrically connected to a pressure transmitter device, which acts on the reaction tank and the gas storage tank to detect the pressure of the reaction tank and the gas storage tank; the PLC controller is also electrically connected to the room temperature constant temperature chamber and the computer.

[0009] Furthermore, the mixing mechanism includes: several injection units for placing different materials, a hose, an electric mixer, a mixing pipe, and a mixing pipe cylinder; the injection unit includes: an injection solenoid valve, an injection electric shut-off valve, an injection shut-off cylinder, an electric glue gun, and a three-way shut-off valve, and the injection shut-off cylinder is connected to the air supply pipeline through the injection solenoid valve and the injection electric shut-off valve.

[0010] The injection shut-off valve cylinder is also connected to the electric glue gun. The electric glue gun is connected to the input end of the glue hose through a three-way shut-off valve. The output end of the glue hose is connected to the electric mixer. The electric mixer is connected to the reaction tank through a mixing pipe. The mixing pipe cylinder acting on the electric mixer is connected to the air supply pipeline, and a mixing solenoid valve and a seventh electric shut-off valve are provided between the two for mixing different materials. Then the mixed material is injected into the reaction tank.

[0011] Furthermore, the piston motion structure includes a piston and an electric push rod connected together. The piston and the gas tank together form a sealed space. The electric push rod is electrically connected to the PLC controller and is used to drive the piston to perform piston motion.

[0012] Furthermore, the reciprocating drive mechanism for the tank includes: a reaction tank lifting solenoid valve, a reaction tank cylinder, and a first branch, a second branch, and a third branch connected in parallel to the gas supply pipeline;

[0013] The first branch is equipped with a first pressure reducing valve, a 1L solenoid valve, and a first electric shut-off valve; the second branch is equipped with a second pressure reducing valve, a 2L solenoid valve, and a second electric shut-off valve; and the third branch is equipped with a third pressure reducing valve, a 5L solenoid valve, and a third electric shut-off valve.

[0014] The first, second, and third branches are respectively connected to the solenoid valve for lifting the reaction tank. The solenoid valve for lifting the reaction tank is connected to the cylinder of the reaction tank. The cylinder of the reaction tank acts on the reaction tank to drive the reaction tank to move up and down reciprocally.

[0015] Furthermore, the room temperature constant temperature chamber is equipped with an air inlet and an air outlet. The air supply line passes through the air inlet and is connected to a compressed air cylinder. The air supply line is also equipped with a ninth electric shut-off valve located outside the room temperature constant temperature chamber. The air outlet line passes through the air outlet and is connected to a gas chromatograph. The air outlet line is also equipped with an eighth electric shut-off valve located outside the room temperature constant temperature chamber.

[0016] This invention also discloses a method for detecting toxic gases during the use of mining materials. This method is based on the toxic gas detection system for mining materials described above, and includes:

[0017] S1: Set the temperature parameters of the room temperature constant temperature chamber to maintain a constant ambient temperature around the reaction vessel;

[0018] S2: Control the mixing mechanism to mix the different materials required for the experiment and input the mixed material into the reaction cup of the reaction vessel;

[0019] S3: Toxic gas is generated inside the reaction vessel. Monitor the pressure inside the reaction vessel and select the equilibrium pressure P1 as the pressure value when the pressure inside the reaction vessel is stable. Control the opening of the outlet pipeline between the reaction vessel and the gas storage tank inlet, and select the equilibrium pressure P2 as the pressure value when the pressure is stable. Based on the equilibrium pressures P1 and P2, determine the free volume V of the gas storage tank. free ;

[0020] S4: Open the exhaust valve connected to the gas storage tank, control the piston movement structure in the gas storage tank, and close the exhaust solenoid valve after the pressure is balanced; control the start of the equalization concentration peristaltic pump to allow the toxic gas in the reaction tank to enter the gas storage tank, and close the outlet pipeline when the pressure in the gas storage tank reaches the required pressure; when the pressure in the reaction tank is stable, determine that the pressure value is the equilibrium pressure P3.

[0021] Open the outlet pipeline between the gas storage tank and the reaction tank to allow the gas in the reaction tank to enter the gas storage tank. When the pressure in the gas storage tank and the reaction tank remains unchanged, determine that the pressure value is the equilibrium pressure P4.

[0022] Based on free volume V free The equilibrium pressures P3 and P4 determine the amount of gas generated by the mixture, Q1.

[0023] S5: Open the gas intake valve on the venting line to release the gas in the storage tank; then close the gas intake valve and control the opening of the gas inlet of the gas chromatograph to measure the volume, composition and concentration of the toxic gas.

[0024] S6: After the mixed materials have reacted completely, gas chromatography analysis is performed using a gas chromatograph to obtain the volume, composition, and concentration of the released gas.

[0025] Furthermore, prior to step S1, the process also includes: leak testing of the room temperature constant temperature chamber.

[0026] Furthermore, in step S3, the free volume V free Determined based on the following expression:

[0027]

[0028] Among them, V free The free volume of the gas storage tank, in cm. 3 V c The free volume of the reaction vessel, in cm. 3Z1 refers to the compressibility factor of the initial gas in the reaction vessel; Z2 refers to the compressibility factor of the gas under equilibrium conditions, not exceeding 100 ml.

[0029] Furthermore, the gas production amount Q1 is determined based on the following expression:

[0030]

[0031] In the formula, V m The gas molar volume is 22.4 L / mol; T indicates system stability (K); P3 indicates the equilibrium pressure obtained when the reactor pressure is stable (MPa); P4 indicates the equilibrium pressure of the toxic gas after complete reaction (MPa); Z3 indicates the gas compressibility coefficient under conditions P3 and T; Z4 indicates the gas compressibility coefficient under conditions P4 and T; v indicates the volume of the mixed material (ml); R indicates the gas constant (R = 8.735 J / (mol·K)).

[0032] The present invention has at least the following beneficial effects:

[0033] This invention establishes an experimental platform in the toxic gas detection system for mining materials, including a room temperature constant temperature chamber, a reaction vessel, a variable volume gas storage tank, a mixing mechanism, and a reciprocating drive mechanism for the tank. The experimental process is intelligently controlled by a PLC controller, realizing intelligent detection of toxic gases generated by different materials during use. This effectively avoids experimental errors caused by manual reading and has the advantages of simple operation and high data accuracy.

[0034] The gas storage tank system disclosed in this invention can accurately measure the volume of toxic gases generated during the material reaction process, effectively avoiding errors when reading the volume.

[0035] Other beneficial effects of the present invention will be described in detail in the Detailed Description of the Embodiments section. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a system block diagram of a toxic gas detection system for the use of mining materials, as disclosed in a preferred embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the structural principle of a toxic gas detection system for the use of mining materials, as disclosed in a preferred embodiment of the present invention.

[0039] Figure 3 This is a schematic diagram of the electrical connection of the PLC controller of the toxic gas detection system for the use of mining materials, as disclosed in a preferred embodiment of the present invention.

[0040] Figure 4 This is a line graph of toxic and harmful gas analysis disclosed in a preferred embodiment of the present invention.

[0041] Among them, 1-compressed air cylinder, 101-first pressure reducing valve, 102-second pressure reducing valve, 103-third pressure reducing valve, 104-1L solenoid valve, 105-2L solenoid valve, 106-5L solenoid valve, 107-first electric shut-off valve, 108-second electric shut-off valve, 109-third electric shut-off valve, 110-reaction tank lifting solenoid valve, 111-fourth electric shut-off valve, 112-reaction tank cylinder, 113-reaction cup;

[0042] 2-Room temperature control chamber; 201-Chamber body; 202-Solenoid valve for material A; 203-Solenoid valve for material B; 204-Mixing solenoid valve; 205-Fifth electric shut-off valve; 206-Sixth electric shut-off valve; 207-Seventh electric shut-off valve; 208-Shut-off cylinder for material A; 209-Shut-off cylinder for material B; 210-Mixing tube cylinder; 211-CNC electric dispensing gun for material A; 212-CNC electric dispensing gun for material B; 213-Three-way shut-off valve for material A; 214-Three-way shut-off valve for material B; 222-Hose; 223-Electric mixer; 224-Mixing tube;

[0043] 3-Reaction vessel; 301-Filter; 302-Equalization concentration peristaltic pump; 303-Screen; 304-Electric push rod; 305-Piston;

[0044] 4-Gas storage tank, 401-Pressure transmitter, 402-Gas intake valve, 403-Exhaust valve, 404-Inlet valve, 405-Gas intake peristaltic pump, 406-Eighth electric shut-off valve, 407-Ninth electric shut-off valve.

[0045] 5- Drain pipe;

[0046] 6-Gas Chromatograph. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0048] This invention discloses a toxic gas detection system for the use of mining materials, which mainly includes: a room temperature constant temperature chamber, a gas chromatograph, a compressed air cylinder, a computer and a PLC controller. The room temperature constant temperature chamber is equipped with: a reaction vessel, a reciprocating drive mechanism for the reaction vessel, a mixing mechanism, the reaction vessel, and a variable volume gas storage tank.

[0049] The compressed air cylinder is connected to the air supply pipeline installed in the room temperature constant temperature chamber. The air supply pipeline is connected to the tank reciprocating drive mechanism and the mixing mechanism for supplying air.

[0050] The reaction vessel is equipped with a reaction cup. The mixing mechanism is connected to the inlet of the reaction vessel. The PLC controller is electrically connected to the mixing mechanism to mix different materials and inject the mixed material into the reaction cup. The reaction vessel is connected to an outlet pipe to connect to a gas storage tank. The outlet pipe is equipped with a filter, a concentration equalization peristaltic valve, and a screen.

[0051] The gas storage tank is equipped with a piston movement mechanism. The PLC controller is electrically connected to the piston movement mechanism to control the change of the volume inside the gas storage tank to adjust the pressure to achieve internal and external balance. The gas storage tank is connected to an venting pipeline for connecting to a gas chromatograph. The venting pipeline is equipped with a gas intake valve and a gas intake peristaltic pump. On the venting pipeline, before the gas intake valve, there are an exhaust branch and an intake branch. The exhaust branch is equipped with an exhaust valve, and the intake branch is equipped with an intake valve.

[0052] The PLC controller is electrically connected to a pressure transmitter device, which acts on the reaction tank and the gas storage tank to detect the pressure of the reaction tank and the gas storage tank; the PLC controller is also electrically connected to the room temperature constant temperature chamber and the computer.

[0053] Furthermore, the mixing mechanism includes: several injection units for placing different materials, a hose, an electric mixer, a mixing pipe, and a mixing pipe cylinder; the injection unit includes: an injection solenoid valve, an injection electric shut-off valve, an injection shut-off cylinder, an electric glue gun, and a three-way shut-off valve, and the injection shut-off cylinder is connected to the air supply pipeline through the injection solenoid valve and the injection electric shut-off valve.

[0054] The injection shut-off valve cylinder is also connected to the electric glue gun. The electric glue gun is connected to the input end of the glue hose through a three-way shut-off valve. The output end of the glue hose is connected to the electric mixer. The electric mixer is connected to the reaction tank through a mixing pipe. The mixing pipe cylinder acting on the electric mixer is connected to the air supply pipeline, and a mixing solenoid valve and a seventh electric shut-off valve are provided between the two for mixing different materials. Then the mixed material is injected into the reaction tank.

[0055] Furthermore, the piston motion structure includes a piston and an electric push rod connected together. The piston and the gas tank together form a sealed space. The electric push rod is electrically connected to the PLC controller and is used to drive the piston to perform piston motion.

[0056] Furthermore, the reciprocating drive mechanism for the tank includes: a reaction tank lifting solenoid valve, a reaction tank cylinder, and a first branch, a second branch, and a third branch connected in parallel to the gas supply pipeline;

[0057] The first branch is equipped with a first pressure reducing valve, a 1L solenoid valve, and a first electric shut-off valve; the second branch is equipped with a second pressure reducing valve, a 2L solenoid valve, and a second electric shut-off valve; and the third branch is equipped with a third pressure reducing valve, a 5L solenoid valve, and a third electric shut-off valve.

[0058] The first, second, and third branches are respectively connected to the solenoid valve for lifting the reaction tank. The solenoid valve for lifting the reaction tank is connected to the cylinder of the reaction tank. The cylinder of the reaction tank acts on the reaction tank to drive the reaction tank to move up and down reciprocally.

[0059] Furthermore, the room temperature constant temperature chamber is equipped with an air inlet and an air outlet. The air supply line passes through the air inlet and is connected to a compressed air cylinder. The air supply line is also equipped with a ninth electric shut-off valve located outside the room temperature constant temperature chamber. The air outlet line passes through the air outlet and is connected to a gas chromatograph. The air outlet line is also equipped with an eighth electric shut-off valve located outside the room temperature constant temperature chamber.

[0060] It is worth mentioning that the pipeline in this invention can be controlled by an electric shut-off valve installed on it. The specific installation method and structure will not be described in detail here.

[0061] The present invention discloses the following embodiment 1, which is used to describe the above-described system in detail.

[0062] Example 1

[0063] like Figures 1 to 3 As shown in the figure, this embodiment discloses a toxic gas detection system for the reaction process of mining materials, including a room temperature constant temperature chamber 2, used to maintain a constant ambient temperature around the reactor and maintain the simulated ambient temperature required for the material reaction process. During gas sampling, the temperature can be continuously adjusted between room temperature and 50℃. Its temperature control range is 20℃~50℃; temperature control accuracy is ±1℃; test duration is 2~12 hours / sample.

[0064] The gas supply pipeline inside the room temperature constant temperature chamber 2 is connected to an external compressed air cylinder 1 to supply gas to the corresponding mechanisms inside the chamber 2. The gas supply pipeline is connected to a mixing mechanism that can mix various materials and inject them into the reaction vessel 3. The reaction vessel 3 is connected to a variable-volume gas storage tank 4. The gas storage tank 4 preferably uses a regular-shaped tube, such as a cylinder, to facilitate obtaining varying volumes. By changing the volume, pressure balance can be achieved inside and outside the tank. The gas storage tank 4 is connected to a gas chromatograph 6 outside the room temperature constant temperature chamber 2. The gas supply pipeline is also connected to a tube reciprocating drive mechanism, which acts on the reaction vessel 3 to drive its movement.

[0065] The system's tank reciprocating drive mechanism has three parallel branches (first branch, second branch, and third branch). Each branch is equipped with a corresponding pressure reducing valve (first pressure reducing valve 101, second pressure reducing valve 102, third pressure reducing valve 103), solenoid valve (1L solenoid valve 104, 2L solenoid valve 105, 5L solenoid valve 106), and electric shut-off valve (first electric shut-off valve 107, second electric shut-off valve 108, third electric shut-off valve 109). The input end of each branch is connected to an air supply pipeline, and a ninth electric shut-off valve 407 controls the opening and closing of the pipeline between the air supply pipeline and the compressed air cylinder 1. The output end of each branch is connected to a reaction tank lifting solenoid valve 110. A fourth electric shut-off valve 111 is installed between the reaction tank lifting solenoid valve 110 and the reaction tank cylinder 112. Based on existing principles, the reaction tank cylinder 112 can drive the reaction tank 3, for example, causing the reaction tank 3 to reciprocate up and down.

[0066] The mixing mechanism is a device that mixes the reaction materials to be tested and then injects them into the reaction vessel 3. The mixing mechanism includes: two injection units for placing different materials, a hose 222, an electric mixer 223, a mixing pipe 224, and a mixing pipe cylinder 210. The injection unit includes: injection solenoid valves (A material solenoid valve 202 and B material solenoid valve 203), injection electric shut-off valves (fifth electric shut-off valve 205 and sixth electric shut-off valve 206), injection shut-off cylinders (A material shut-off cylinder 208 and B material shut-off cylinder 209), electric glue guns (A material CNC electric glue gun 211 and B material CNC electric glue gun 212), and three-way shut-off valves (A material three-way shut-off valve 213 and B material three-way shut-off valve 214). The injection shut-off cylinders are connected to the air supply pipeline through the injection solenoid valves and the injection electric shut-off valves.

[0067] The injection shut-off valve cylinder is also connected to the electric glue gun. The electric glue gun is connected to the input end of the glue tube 222 through a three-way shut-off valve. The output end of the glue tube 222 is connected to the electric mixer 223. The electric mixer 223 is connected to the reaction tank through the mixing pipe 224. The mixing pipe cylinder 210 acting on the electric mixer 223 is connected to the air supply pipeline, and a mixing solenoid valve 204 and a seventh electric shut-off valve 207 are provided between the two for mixing different materials and then injecting the mixed material into the reaction tank.

[0068] The gases released during the reaction of the mixed reaction materials mainly accumulate in the reaction cup 113, which is located inside the reaction vessel 3. A variable-volume gas storage tank 4 is connected to the reaction vessel 3 via a pipeline, and a filter 301, a concentration equalization peristaltic pump 302, and a screen 303 are installed between them. The gas storage tank 4 stores the reaction gases to be collected. Combined with the concentration equalization peristaltic pump 302, it can completely collect the test gases generated during the experimental stage. The PLC controller can control the electric push rod 304 to drive the piston 305, changing the volume of the gas storage tank 4 and thus adjusting the pressure to achieve pressure balance inside and outside the gas storage tank 4. In this embodiment, the gas storage tank 4 can have a regular shape, such as a cylindrical body. The piston 305 movement mechanism of the gas storage tank 4 adopts a straight-cylinder piston 305 structure. The displacement of the piston 305 driven by the electric push rod 304 can obtain the internal volume of the gas storage tank 4 in real time. After calculating the internal volume of the reaction vessel 3, the accurate reaction gas volume is obtained. The pressure transmitter feeds back the pressure changes in the four gas storage tanks to the PLC controller in real time, which in turn enables the PLC controller to control the electric push rod 304 to drive the piston 305 to move based on the pressure changes.

[0069] The gas chromatograph 6, used for detecting gas concentration, is located outside the enclosure 201, while the reaction vessel 3 and the variable-volume gas storage tank 4 are located inside the room temperature constant temperature chamber 2. The gas chromatograph 6 is connected to the outlet of the gas storage tank 4 via a vent pipe 5, which is equipped with a gas intake valve 402, an exhaust valve 403, an intake valve 404, a gas intake peristaltic pump 405, and an eighth electric shut-off valve 406. The outlet of the gas storage tank 4 is used to connect to the chromatographic analysis interface of the gas chromatograph 6.

[0070] In this embodiment, the pressure transmitter device includes a pressure transmitter 401 installed in the vent line 5, enabling it to detect the pressure of the gas storage tank 4. The reaction tank 3 is also connected to the vent line 5, allowing the pressure transmitter 401 to detect the pressure of the reaction tank 3. Alternatively, the pressure transmitter may include pressure sensors correspondingly installed in the gas storage tank 4 and the reaction tank 3.

[0071] like Figure 3 As shown, the PLC controller is electrically connected to a pressure transmitter to collect the pressure of the reaction tank 3 and the gas storage tank 4, and to monitor the pressure changes in the gas storage tank 4 and the reaction tank 3 during the generation of toxic gases. Preferably, the PLC controller can also be connected to a temperature sensor device, which can detect the temperature of the reaction tank 3 and other parts by setting it at a corresponding position in the room temperature constant temperature chamber 2. The PLC controller is also connected to and controls the opening and closing of the various electric shut-off valves and solenoid valves mentioned in this invention.

[0072] This invention also discloses a method for detecting toxic gases during the use of mining materials. This method is based on the toxic gas detection system for mining materials described above, and includes:

[0073] S1: Set the temperature parameters of the room temperature constant temperature chamber to maintain a constant ambient temperature around the reaction vessel;

[0074] S2: Control the mixing mechanism to mix the different materials required for the experiment and input the mixed material into the reaction cup of the reaction vessel;

[0075] S3: Toxic gas is generated inside the reaction vessel. Monitor the pressure inside the reaction vessel and select the equilibrium pressure P1 as the pressure value when the pressure inside the reaction vessel is stable. Control the opening of the outlet pipeline between the reaction vessel and the gas storage tank inlet, and select the equilibrium pressure P2 as the pressure value when the pressure is stable. Based on the equilibrium pressures P1 and P2, determine the free volume V of the gas storage tank. free ;

[0076] S4: Open the exhaust valve connected to the gas storage tank, control the piston movement structure in the gas storage tank, and close the exhaust solenoid valve after the pressure is balanced; control the start of the equalization concentration peristaltic pump to allow the toxic gas in the reaction tank to enter the gas storage tank, and close the outlet pipeline when the pressure in the gas storage tank reaches the required pressure; when the pressure in the reaction tank is stable, determine that the pressure value is the equilibrium pressure P3.

[0077] Open the outlet pipeline between the gas storage tank and the reaction tank to allow the gas in the reaction tank to enter the gas storage tank. When the pressure in the gas storage tank and the reaction tank remains unchanged, determine that the pressure value is the equilibrium pressure P4.

[0078] Based on free volume V free The equilibrium pressures P3 and P4 determine the amount of gas generated by the mixture, Q1.

[0079] S5: Open the gas intake valve on the venting line to release the gas in the storage tank; then close the gas intake valve and control the opening of the gas inlet of the gas chromatograph to measure the volume, composition and concentration of the toxic gas.

[0080] S6: After the mixed materials have reacted completely, gas chromatography analysis is performed using a gas chromatograph to obtain the volume, composition, and concentration of the released gas.

[0081] Furthermore, prior to step S1, the process also includes: leak testing of the room temperature constant temperature chamber.

[0082] Furthermore, in step S3, the free volume V free Determined based on the following expression:

[0083]

[0084] Among them, V free The free volume of the gas storage tank, in cm. 3 V cThe free volume of the reaction vessel, in cm. 3 Z1 refers to the compressibility factor of the initial gas in the reaction vessel; Z2 refers to the compressibility factor of the gas under equilibrium conditions, not exceeding 100 ml.

[0085] Furthermore, the gas production amount Q1 is determined based on the following expression:

[0086]

[0087] In the formula, V m The gas molar volume is 22.4 L / mol; T indicates system stability (K); P3 indicates the equilibrium pressure obtained when the reactor pressure is stable (MPa); P4 indicates the equilibrium pressure of the toxic gas after complete reaction (MPa); Z3 indicates the gas compressibility coefficient under conditions P3 and T; Z4 indicates the gas compressibility coefficient under conditions P4 and T; v indicates the volume of the mixed material (ml); R indicates the gas constant (R = 8.735 J / (mol·K)).

[0088] The present invention discloses the following two embodiments, namely, Embodiment 2 and Embodiment 3, for illustrating the above-described method in detail.

[0089] Example 2

[0090] The method for detecting toxic gases during the use of mining materials disclosed in this embodiment includes:

[0091] The mixed mining materials are placed in the reaction vessel of the room temperature constant temperature chamber, and the air source is turned on to check for leaks in the room temperature constant temperature chamber. After the leak is checked, the cylinder presses down materials A and B respectively and injects them into the electric mixer. The electric mixer fully mixes materials A and B and sends them into the reaction cup.

[0092] The reaction vessel in the room temperature constant temperature chamber generates toxic gases until the pressure inside the reaction vessel stabilizes, obtaining the equilibrium pressure P1. The series pipeline between the reaction vessel outlet and the gas storage tank inlet is then opened, allowing the toxic gases generated in the reaction vessel to enter the gas storage tank. When the pressure stabilizes, the equilibrium pressure P2 is obtained. During the process of the pressure transmitter returning to zero, i.e., maintaining the entire system at atmospheric pressure, an electric push rod, driven by a servo motor, drives the piston to displace, increasing the volume and causing the pressure to return to the equilibrium pressure. Based on the equilibrium pressures P1 and P2, the known free volume Vc of the reaction vessel, and combining the gas law of state and the law of conservation of mass, the free volume V of the gas storage tank is obtained. free .

[0093] The equalization concentration peristaltic pump actively circulates the toxic gas generated in the reaction tank, and then closes the series pipeline between the reaction tank outlet and the gas storage tank inlet until the reaction tank reaches the predetermined pressure. When the reaction tank pressure stabilizes, its equilibrium pressure P3 is obtained.

[0094] Open all the series pipelines between the outlet of the reaction tank and the inlet of the gas storage tank so that the toxic gas generated in the reaction tank can enter the gas storage tank until the pressure stabilizes and the equilibrium pressure P4 is obtained; based on P1 and P2 and combined with the gas state equation and the law of conservation of mass, the amount of gas generated by the mixture of the two mining materials is obtained, Q1.

[0095] Close the series pipeline between the reaction vessel and the gas storage tank, and replenish the reaction vessel with the generated toxic gas quantity Q1 to a higher predetermined pressure. The volume of the generated gas is the free volume V of the reaction vessel. free Open the series pipeline between the outlet of the reaction tank and the inlet of the gas storage tank to allow the toxic gas to enter the gas storage tank.

[0096] Open the gas intake valve on the venting pipeline connected to the gas storage tank to release the toxic gas; then close the gas intake valve and open the eighth electric shut-off valve at the gas inlet of the gas chromatograph so that the gas chromatograph can measure the volume, composition and concentration of the toxic gas.

[0097] After the material reaction is complete, gas chromatography analysis is performed using a gas chromatograph to obtain the volume, components, and concentration of the released gas.

[0098] Example 3

[0099] The method for detecting toxic gases during the use of mining materials disclosed in this embodiment includes:

[0100] 1. Place the mining materials into the CNC electric glue guns for material A and material B, open the compressed air cylinder and the ninth electric shut-off valve on its connection to the room temperature constant temperature chamber. Under the control of the PLC controller, raise the temperature of the room temperature constant temperature chamber to 20°C and check for leaks in the internal pipelines and tanks. After the leak check is completed, close all the electric shut-off valves of the room temperature constant temperature chamber to prevent it from being connected to the external gas supply device. Also, disconnect the series pipeline between the outlet of the reaction tank and the inlet of the gas storage tank in the room temperature constant temperature chamber to facilitate subsequent equilibrium pressure measurement.

[0101] 2. Open the ninth electric shut-off valve on the air supply line where the compressed air cylinder is located to introduce air into the room temperature constant temperature chamber, which is used to provide air source for the pneumatic devices of the entire air circuit.

[0102] A pressure transmitter is used to monitor the gas storage tank. After closing all electrically operated shut-off valves and allowing the gas storage tank pressure to stabilize, the equilibrium pressure P1, i.e., the initial equilibrium pressure of the toxic gas, is recorded. Then, the shut-off valve on the reaction tank pipeline is opened and kept open as the input gas pipeline. After the material reaction is complete, the shut-off valve on the reaction tank pipeline is closed. The shut-off valve on the gas storage tank pipeline is then opened, allowing the toxic gas from the reaction tank to enter the gas storage tank. When the pressure in both tanks remains constant, the equilibrium pressure P2, i.e., the secondary equilibrium pressure of the toxic gas, is recorded. The free volume V of the gas storage tank is calculated based on the gas law of state (PV = nZRT) and the law of conservation of mass. free See equation (1) below:

[0103] Once the pressure in reaction vessel 3 stabilizes, i.e. the initial equilibrium pressure of the toxic gas;

[0104]

[0105] In the formula: V free The free volume of the gas storage tank, in cm. 3 ;

[0106] P1 and P2 refer to the initial equilibrium pressure and the secondary equilibrium pressure of the toxic gas in the reaction vessel, respectively, in MPa;

[0107] V c The free volume of the reaction vessel, in cm. 3 ;

[0108] Z1 refers to the compressibility factor of the initial gas in the reactor.

[0109] Z2 refers to the compressibility factor of a gas under equilibrium conditions, not exceeding 100 ml;

[0110] 3. The free volume V to be determined free After the measurement is completed, open the exhaust valve of the gas tank, which will automatically lower the piston position of the gas tank by 50mm. After the pressure is balanced (to zero), close the exhaust valve.

[0111] Open the electric shut-off valve and the equalization concentration peristaltic pump on the corresponding pipeline to allow the toxic gas to enter the gas storage tank. Monitor the pressure in the gas storage tank. When the required pressure is reached, close the electric shut-off valve. When the pressure stabilizes, record the equilibrium pressure P3, which is the initial equilibrium pressure of the toxic gas.

[0112] 4. Connect the gas storage tank and the reaction tank in series to allow the gas in the reaction tank to enter the gas storage tank. When the pressure in both tanks remains constant, record the equilibrium pressure P4, which is the gas equilibrium pressure. Calculate the amount of gas produced at the equilibrium pressure using the gas law of state and the law of conservation of mass, as shown in method (2) below:

[0113]

[0114] In the formula: V m Refers to the molar volume of a gas;

[0115] T indicates system stability, K;

[0116] P3 refers to the initial equilibrium pressure of methane gas in the reaction vessel, in MPa;

[0117] P4 refers to the equilibrium pressure, in MPa;

[0118] Z3 refers to the gas compressibility coefficient under P3 and T conditions;

[0119] Z4 refers to the gas compressibility coefficient under P4 and T conditions;

[0120] m refers to the mass of the coal sample, in grams;

[0121] R refers to the gas constant, R = 8.735 J / (mol·K).

[0122] 5. Open the gas inlet valve of the gas storage tank's venting line to release the gas from the tank; then close the gas inlet valve of the venting line, open the eighth electric shut-off valve at the gas inlet of the gas chromatograph, and measure the volume of the toxic gas.

[0123] 6. Open all electric shut-off valves on the pipeline connecting to the gas inlet of the gas storage tank, set the parameters of the room temperature constant temperature chamber through the computer-controlled PLC controller, and perform gas chromatography analysis using a gas chromatograph to obtain the components and concentrations of the released gas.

[0124] The above steps can be automatically controlled by the PLC controller and computer in this invention, including controlling the opening and closing of the electric shut-off valve, collecting sensor data, setting parameters, etc., and have the advantages of being simple to use and easy to operate.

[0125] Finally, the equipment shutdown and maintenance steps after the experiment are completed are as follows: close the compressed air cylinder and the electric shut-off valve of the gas chromatograph, and clean up the residual coal sample after the reaction vessel temperature drops to room temperature.

[0126] Experiments conducted using the systems and methods disclosed in the above embodiments yielded the following results: Figure 4 The line graph showing the analysis of toxic and harmful gases can analyze the concentration changes of gases including NH4, CO2, CO, NO2, SO2, and O2.

[0127] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for detecting toxic gases during the use of mining materials, characterized in that, This method is based on a toxic gas detection system for the use of mining materials. The toxic gas detection system for the use of mining materials includes: a room temperature constant temperature chamber, a gas chromatograph, a compressed air cylinder, a computer and a PLC controller. The room temperature constant temperature chamber is equipped with: a reaction vessel, a reciprocating drive mechanism for the reaction vessel, a mixing mechanism, the reaction vessel and a variable volume gas storage tank. The compressed air cylinder is connected to the air supply pipeline installed in the room temperature constant temperature chamber. The air supply pipeline is connected to the tank reciprocating drive mechanism and the mixing mechanism for supplying air. The reaction vessel is equipped with a reaction cup. The mixing mechanism is connected to the inlet of the reaction vessel. The PLC controller is electrically connected to the mixing mechanism to mix different materials and inject the mixed material into the reaction cup. The reaction vessel is connected to an outlet pipe to connect to a gas storage tank. The outlet pipe is equipped with a filter, a concentration equalization peristaltic valve, and a screen. The gas storage tank is equipped with a piston movement mechanism. The PLC controller is electrically connected to the piston movement mechanism to control the change of the volume inside the gas storage tank to adjust the pressure to the internal and external balance. The gas storage tank is connected to an emptying pipeline for connecting to a gas chromatograph. The emptying pipeline is equipped with a gas intake valve and a gas intake peristaltic pump. On the emptying pipeline, before the gas intake valve, there are an exhaust branch and an intake branch. The exhaust branch is equipped with an exhaust valve, and the intake branch is equipped with an intake valve. The PLC controller is electrically connected to a pressure transmitter device, which acts on the reaction tank and the gas storage tank to detect the pressure of the reaction tank and the gas storage tank; the PLC controller is also electrically connected to the room temperature constant temperature chamber and the computer. The method includes the following steps: S1: Set the temperature parameters of the room temperature constant temperature chamber to maintain a constant ambient temperature around the reaction vessel; S2: Control the mixing mechanism to mix the different materials required for the experiment and input the mixed material into the reaction cup of the reaction vessel; S3: Toxic gas is generated inside the reaction vessel. Monitor the pressure inside the reaction vessel and select the equilibrium pressure P1 as the pressure value when the pressure inside the reaction vessel is stable. Control the opening of the outlet pipeline between the reaction vessel and the gas storage tank inlet, and select the equilibrium pressure P2 as the pressure value when the pressure is stable. Based on the equilibrium pressures P1 and P2, determine the free volume V of the gas storage tank. free Free volume V free Determined based on the following expression: ； Among them, V free The free volume of the gas storage tank, in cm. 3 V c The free volume of the reaction vessel, in cm. 3 Z1 refers to the compressibility factor of the initial gas in the reaction vessel; Z2 refers to the compressibility factor of the gas under equilibrium conditions, not exceeding 100 ml. S4: Open the exhaust valve connected to the gas storage tank, control the piston movement structure in the gas storage tank, and close the exhaust solenoid valve after the pressure is balanced; control the start of the equalization concentration peristaltic pump to allow the toxic gas in the reaction tank to enter the gas storage tank; when the pressure in the gas storage tank reaches the required pressure, close the series pipeline between the reaction tank outlet and the gas storage tank inlet; when the reaction tank pressure is stable, determine that the pressure value is the equilibrium pressure P3; Open the outlet pipeline between the gas storage tank and the reaction tank to allow the toxic gas generated in the reaction tank to enter the gas storage tank. When the pressure in the gas storage tank and the reaction tank remains unchanged, determine that the pressure value is the equilibrium pressure P4. Based on free volume V free The equilibrium pressures P3 and P4 determine the amount of gas generated by the mixture, Q1. The amount of gas produced, Q1, is determined based on the following expression: ； In the formula, V m The values ​​are: ρ = 22.4 L / mol; T = K (system stability); P3 = MPa (equilibrium pressure when the reactor pressure is stable); P4 = MPa (equilibrium pressure of toxic gases after complete reaction); Z3 = gas compressibility coefficient under conditions P3 and T; Z4 = gas compressibility coefficient under conditions P4 and T; v = volume of mixed material (ml); R = gas constant (R = 8.735 J / (mol·K)). S5: Open the gas intake valve on the venting line to release the gas in the storage tank; then close the gas intake valve and control the opening of the gas inlet of the gas chromatograph to measure the volume, composition and concentration of the toxic gas. S6: After the mixed materials have reacted completely, gas chromatography analysis is performed using a gas chromatograph to obtain the volume, composition, and concentration of the released gas.

2. The method for detecting toxic gases during the use of mining materials according to claim 1, characterized in that, Before step S1, the following steps are also included: leak detection of the room temperature constant temperature chamber.

3. The method for detecting toxic gases during the use of mining materials according to claim 1, characterized in that, The mixing mechanism includes: several injection units for placing different materials, a hose, an electric mixer, a mixing pipe and a mixing pipe cylinder; the injection unit includes: an injection solenoid valve, an injection electric shut-off valve, an injection shut-off cylinder, an electric glue gun and a three-way shut-off valve, and the injection shut-off cylinder is connected to the air supply line through the injection solenoid valve and the injection electric shut-off valve. The injection shut-off valve cylinder is also connected to the electric glue gun. The electric glue gun is connected to the input end of the glue hose through a three-way shut-off valve. The output end of the glue hose is connected to the electric mixer. The electric mixer is connected to the reaction tank through a mixing pipe. The mixing pipe cylinder acting on the electric mixer is connected to the air supply pipeline, and a mixing solenoid valve and a seventh electric shut-off valve are provided between the two for mixing different materials. Then the mixed material is injected into the reaction tank.

4. The method for detecting toxic gases during the use of mining materials according to claim 1, characterized in that, The piston motion structure includes a piston and an electric push rod connected together. The piston and the gas tank together form a sealed space. The electric push rod is electrically connected to the PLC controller and is used to drive the piston to perform piston motion.

5. The method for detecting toxic gases during the use of mining materials according to claim 1, characterized in that, The tank reciprocating drive mechanism includes: a reaction tank lifting solenoid valve and a reaction tank cylinder, as well as a first branch, a second branch and a third branch connected in parallel to the gas supply pipeline; The first branch is equipped with a first pressure reducing valve, a 1L solenoid valve and a first electric shut-off valve; the second branch is equipped with a second pressure reducing valve, a 2L solenoid valve and a second electric shut-off valve; and the third branch is equipped with a third pressure reducing valve, a 5L solenoid valve and a third electric shut-off valve. The first, second, and third branches are respectively connected to the solenoid valve for lifting the reaction vessel. The solenoid valve for lifting the reaction vessel is connected to the cylinder of the reaction vessel. The cylinder of the reaction vessel acts on the reaction vessel to drive the reaction vessel to move up and down reciprocally.

6. The method for detecting toxic gases during the use of mining materials according to claim 1, characterized in that, The room temperature constant temperature chamber is equipped with an air inlet and an air outlet. The air supply line passes through the air inlet and is connected to a compressed air cylinder. The air supply line is also equipped with a ninth electric shut-off valve located outside the room temperature constant temperature chamber. The air outlet line passes through the air outlet and is connected to a gas chromatograph. The air outlet line is also equipped with an eighth electric shut-off valve located outside the room temperature constant temperature chamber.

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