Induced jet ventilation system for assisting in discharging harmful gas

Abstract

The utility model discloses an induced jet ventilation system assisting in discharging harmful gas, which comprises an air supply device, exhaust pipes and an air outlet pipe, the exhaust pipes comprise a first exhaust pipe, a second exhaust pipe and a third exhaust pipe, the first exhaust pipe is connected with the second exhaust pipe, the second exhaust pipe is connected with the third exhaust pipe, and the air outlet pipe is connected with the air supply device. The pipe diameter of the inlet end of the first exhaust pipe is larger than that of the outlet end, a plurality of first induction air ports are symmetrically formed in the left side wall and the right side wall of the first exhaust pipe, the pipe diameter of the outlet end of the third exhaust pipe is larger than that of the inlet end, and a plurality of second induction air ports are symmetrically formed in the left side wall and the right side wall of the third exhaust pipe. The first induction air opening and the second induction air opening are formed in the exhaust pipe, negative pressure is generated in the exhaust pipe through high-speed airflow ejected by gas jet flow, surrounding airflow is driven to enter the exhaust pipe through the first induction air opening and the second induction air opening, and the purpose of supplying large air quantity with small flow is achieved. The problem of low ventilation efficiency caused by insufficient air volume in the welding pipeline is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a ventilation system technical field especially is related to a kind of induced jet ventilation system of auxiliary discharge harmful gas. BACKGROUND

[0002] In modern industry, pipeline welding is widely used in petroleum, natural gas, chemical industry and other fields;However, a large amount of harmful gases such as carbon monoxide, nitrogen oxides and ozone are generated during welding process;These harmful gases not only pose a threat to the health of welding operators, but also may pollute the surrounding environment;According to relevant occupational health and safety standards, welding operation needs to ensure effective ventilation to reduce the concentration of harmful gases and protect the safety of operators;At present, natural ventilation or mechanical ventilation is commonly used in welding operation;However, these traditional ventilation methods have problems such as insufficient air volume, low ventilation efficiency and unsatisfactory ventilation effect in practical application;Therefore, it is necessary to design a ventilation system that can increase ventilation volume and efficiency. SUMMARY

[0003] The utility model aims at overcoming the insufficient of prior art, provide a kind of induced jet ventilation system of auxiliary discharge harmful gas, the utility model is provided with first induced air port and second induced air port on exhaust duct, the high-speed airflow emitted by gas jet generates negative pressure in exhaust duct, drives surrounding airflow to enter exhaust duct through first induced air port and second induced air port, realizes the purpose of sending large air volume with small flow, solves the problem of low ventilation efficiency caused by insufficient air volume in welding pipeline.

[0004] To achieve the above purpose, the utility model adopts the technical scheme of: a kind of induced jet ventilation system of auxiliary discharge harmful gas, including air supply device, exhaust duct and air outlet pipe, the outlet end of air supply device is connected with exhaust duct, the end portion of exhaust duct away from air supply device is connected with air outlet pipe for adjusting the size and air outlet direction of air outlet, the exhaust duct includes first exhaust duct, second exhaust duct and third exhaust duct, the outlet end of first exhaust duct is connected with the inlet end of second exhaust duct, the outlet end of second exhaust duct is connected with the inlet end of third exhaust duct, the pipe diameter of first exhaust duct inlet end is greater than the pipe diameter of outlet end, the left and right two side walls of first exhaust duct are symmetrically provided with a plurality of first induced air ports, a plurality of first induced air ports are arranged at equal intervals, the pipe diameter of second exhaust duct inlet end is consistent with the pipe diameter of first exhaust duct outlet end, the pipe diameter of second exhaust duct outlet end is consistent with the pipe diameter of third exhaust duct inlet end, the pipe diameter of third exhaust duct outlet end is greater than the pipe diameter of inlet end, the left and right two side walls of third exhaust duct are symmetrically provided with a plurality of second induced air ports, a plurality of second induced air ports are arranged at equal intervals.

[0005] Preferably, the air supply device comprises an air supply pipe, an axial flow fan, an automatic control device and a first air pipe, the axial flow fan and the first air pipe are both installed in the air supply pipe, the automatic control device is installed on the side wall of the air supply pipe and is electrically connected with the axial flow fan, the air inlet of the first air pipe is connected with the air outlet of the axial flow fan, and the air outlet of the first air pipe extends to the air outlet of the air supply pipe.

[0006] Preferably, the top and bottom of the air supply pipe are both in an arched structure, the arched structure of the top of the air supply pipe protrudes upward, the arched structure of the bottom of the air supply pipe protrudes downward, and the left and right side walls of the air supply pipe are both perpendicular to the horizontal plane.

[0007] Preferably, the first exhaust pipe comprises a first tapered air pipe, a second tapered air pipe and a first diffusion air pipe, the air outlet of the second tapered air pipe and the air inlet of the first diffusion air pipe are connected and nested in the first tapered air pipe, the outer wall of the second tapered air pipe and the outer wall of the first diffusion air pipe are both spaced from the inner wall of the first tapered air pipe, the air outlet of the first diffusion air pipe is spaced from the air outlet of the first tapered air pipe, the air inlet of the first tapered air pipe and the air inlet of the second tapered air pipe are located in the same vertical plane and are closely connected with the outlet end of the air supply device, and the first induced air inlet is located on the side wall of the first tapered air pipe along the length direction.

[0008] Preferably, the second exhaust pipe is a second diffusion air pipe, the air inlet of the second diffusion air pipe is connected with the air outlet of the first tapered air pipe, the size and shape of the air inlet of the second diffusion air pipe are consistent with the size and shape of the air outlet of the first tapered air pipe, the air outlet of the second diffusion air pipe is connected with the air inlet of the third exhaust pipe, and the size and shape of the air outlet of the second diffusion air pipe are consistent with the size and shape of the air inlet of the third exhaust pipe.

[0009] Preferably, the third exhaust pipe comprises a first gradually expanding air pipe and a third diffusion air pipe, the air inlet of the first gradually expanding air pipe is connected with the air outlet of the second diffusion air pipe, the air outlet of the first gradually expanding air pipe is connected with the air inlet of the third diffusion air pipe, the air outlet of the third diffusion air pipe is connected with the air outlet pipe, and the second induced air inlet is located on the side wall of the first gradually expanding air pipe along the length direction.

[0010] Preferably, the air outlet pipe is an adjustable nozzle, the adjustable nozzle comprises a fixed part and an adjusting part, the fixed part is connected with the air outlet of the third exhaust pipe, and the adjusting part is slidingly connected with the outer side wall of the fixed part to facilitate changing the size of the air outlet of the adjustable nozzle.

[0011] Preferably, the induced jet flow ventilation system further comprises a plurality of gas monitoring systems, each of the gas monitoring systems is in communication connection with the automatic control device.

[0012] Preferably, the first and second induced air inlets are circular holes.

[0013] Compared with the prior art, the utility model has the following advantages:

[0014] 1. The first and second induced air inlets are circular holes.

[0015] 2. The axial flow fan of the utility model adopts a small-sized fan. With the advancement of the welding process, the induced ventilation system is extended into the welding pipeline in a pushing manner, thereby increasing the effective distance of air supply and improving the ventilation efficiency of the long pipeline.

[0016] 3. The air outlet pipe of the utility model adopts an adjustable nozzle. The adjustable nozzle changes the size and direction of the air outlet by adjusting the extension degree of the blade, thereby affecting the delivery of air flow organization and solving the problem of uneven air flow or excessive air volume in the welding pipeline affecting the welding effect.

[0017] 4. The utility model adopts a gas monitoring system and an automatic control device. Multiple gas monitoring systems are installed at intervals in the welding pipeline to monitor the concentration change of harmful gases in the welding pipeline in real time and transmit the monitoring data to the automatic control device. The automatic control device adjusts the power of the axial flow fan and the size and direction of the air outlet of the adjustable nozzle to accurately monitor the concentration of harmful gases in the pipeline and ensure the personal safety of the welding workers and the welding efficiency.

[0018] The utility model will be further described in detail below with reference to the drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The utility model is a structural schematic view.

[0020] BRIEF DESCRIPTION OF DRAWINGS

[0021] 1 - air supply pipe; 2 - axial flow fan; 3 - automatic control device;

[0022] 4 - first air pipe; 5 - first tapered air pipe; 6 - first induced air inlet;

[0023] 7 - second tapered air pipe; 8 - first diffusion air pipe; 9 - second diffusion air pipe;

[0024] 10 - first gradually expanding air pipe; 11 - second induced air inlet; 12 - third diffusion air pipe;

[0025] 13 - adjustable nozzle; 13-1 - fixed part; 13-2 - adjustment part. DETAILED DESCRIPTION

[0026] As Figure 1 shown, the utility model discloses a kind of auxiliary discharge harmful gas's induced jet ventilation system, including air supply device, exhaust pipe and air outlet pipe, the export end of air supply device is connected with exhaust pipe, the end of exhaust pipe away from air supply device is connected with the air outlet pipe for adjusting air outlet size and air outlet direction, exhaust pipe includes first exhaust pipe, second exhaust pipe and third exhaust pipe, the export end of first exhaust pipe is connected with the inlet end of second exhaust pipe, the export end of second exhaust pipe is connected with the inlet end of third exhaust pipe, the pipe diameter of first exhaust pipe inlet end is greater than the pipe diameter of export end, the left and right two sides of first exhaust pipe are symmetrically equipped with multiple first induced air port 6, multiple first induced air port 6 are equidistantly arranged, the pipe diameter of second exhaust pipe inlet end is consistent with the pipe diameter of first exhaust pipe export end, the pipe diameter of second exhaust pipe export end is consistent with the pipe diameter of third exhaust pipe inlet end, the pipe diameter of third exhaust pipe export end is greater than the pipe diameter of inlet end, the left and right two sides of third exhaust pipe are symmetrically equipped with multiple second induced air port 11, multiple second induced air port 11 are equidistantly arranged.

[0027] In the embodiment, air supply device transports air flow to exhaust pipe, first exhaust pipe, second exhaust pipe and third exhaust pipe form venturi structure, multiple first induced air port 6 are evenly arranged in the left and right sides along the length direction of first exhaust pipe, multiple second induced air port 11 are evenly arranged in the left and right sides along the length direction of third exhaust pipe, the air supply of exhaust pipe is increased by first induced air port 6 and second induced air port 11, when air flow enters first exhaust pipe, the diameter of first exhaust pipe gradually reduces, then air flow in first exhaust pipe makes surrounding air generate negative pressure, and then drives external air to converge with main air flow through first induced air port 6, to increase the air supply of main air flow, after convergence, main air flow is in disorder state and changes from turbulent flow to laminar flow in second exhaust pipe, when main air flow enters third exhaust pipe, the diameter of third exhaust pipe gradually increases, and main air flow moves along the center of third exhaust pipe, thus negative pressure zone is formed along the wall of third exhaust pipe, and negative pressure zone drives surrounding airflow to intersect with main air flow through second induced air port 11, to increase the air supply of main air flow in third exhaust pipe;Then main air flow flows into welding pipeline in the form of annular jet through air outlet pipe, because the initial speed of airflow jet is fast, drive surrounding gas to flow along main airflow, and then drive the gas in whole welding pipeline to flow, to realize ventilation in welding pipeline.

[0028] In another possible embodiment, mobile trolley is arranged at the bottom of induced jet ventilation system, and mobile trolley supports air supply device, exhaust pipe and air outlet pipe upwards, when welding point in welding pipeline is replaced, induced jet ventilation system can be pushed to the welding point to be welded through mobile trolley.

[0029] The air supply device comprises an air supply pipe 1, an axial flow fan 2, an automatic control device 3 and a first air pipe 4, the axial flow fan 2 and the first air pipe 4 are both installed in the air supply pipe 1, the automatic control device 3 is installed on the side wall of the air supply pipe 1 and is electrically connected with the axial flow fan 2, the air inlet of the first air pipe 4 is connected with the air outlet of the axial flow fan 2, and the air outlet of the first air pipe 4 extends to the air outlet of the air supply pipe 1.

[0030] In the embodiment, the axial flow fan 2 can be selected according to the air supply amount, which can be an EBM-Papst axial flow fan or an axial flow fan produced by Shanghai Ventilation Equipment Co., Ltd.; the automatic control device 3 adopts a PLC controller, which can be a Siemens PLC controller with a model of S7-200 or other models, and a plurality of harmful gas concentration thresholds are preset, when the gas concentration received by the automatic control device 3 exceeds the preset concentration threshold, the power of the axial flow fan 2 and the size of the air outlet of the air outlet pipe are adjusted through the automatic control device 3; the diameter of the air inlet of the first air pipe 4 is consistent with the diameter of the air outlet of the axial flow fan 2, the diameter of the first air pipe 4 is smaller than the pipeline diameter of the air supply pipe 1, the air inlet of the first air pipe 4 is connected with the air outlet of the axial flow fan 2 to send the airflow generated by the axial flow fan 2 into the first air pipe, the end of the first air pipe 4 away from the axial flow fan 2 along the length direction is located in the same vertical plane with the air outlet of the air supply pipe 1 to facilitate the connection of the first air pipe, the axial flow fan 2 is installed in the air supply pipe 1, the automatic control device 3 is installed on the outer side wall of the air supply pipe 1, and the power of the axial flow fan 2 is adjusted through the automatic control device 3; in use, the axial flow fan 2 is started, and the axial flow fan 2 delivers airflow to the first air pipe 4.

[0031] Further, the air supply pipe 1 is provided with an air filter screen away from the end of the first air pipe 4 along the length direction, so as to avoid large particles in the welded pipeline from entering the air supply pipe 1 and damaging the equipment in the air supply pipe 1, thereby prolonging the service life of the equipment.

[0032] The top and bottom of the air supply pipe 1 are both arc-shaped structures, the arc-shaped structure at the top of the air supply pipe 1 protrudes upward, the arc-shaped structure at the bottom of the air supply pipe 1 protrudes downward, and the left and right side walls of the air supply pipe 1 are both perpendicular to the horizontal plane.

[0033] In this embodiment, the left and right side walls of the air supply pipe 1 are vertical planes, the height of the two side walls of the air supply pipe 1 is determined by the height of the axial flow fan 2 and the automatic control device 3, which facilitates the connection of the axial flow fan 2, the automatic control device 3 and the side wall of the air supply pipe 1, the width of the air supply pipe 1 is determined by the width of the axial flow fan 2, which facilitates the installation of the axial flow fan 2 in the air supply pipe 1, the automatic control device 3 is installed on the outer side wall of the air supply pipe 1, the center axis of the outlet of the axial flow fan 2 coincides with the center axis of the air supply pipe 1, through the fixed connection of the air supply pipe 1 with the axial flow fan 2 and the automatic control device 3, the equipment volume is reduced, and the stability of the axial flow fan 2 and the automatic control device 3 is improved; at the same time, the arch structure at the top and bottom of the air supply pipe 1, in the case of high-speed airflow emitted by the axial flow fan 2, negative pressure will be generated in the arch structure of the air supply pipe 1, driving the external airflow to converge with the airflow sent by the axial flow fan 2, thereby increasing the air supply volume.

[0034] In another possible embodiment, the air supply pipe 1 is a hollow cylindrical pipe, a support table is arranged on one side wall of the air supply pipe 1 to facilitate upward support of the axial flow fan 2 and the automatic control device 3, the bottom of the support table is connected with the inner side wall of the air supply pipe 1, the top of the support table is horizontal, the axial flow fan 2 and the automatic control device 3 are fixedly installed on the top of the support table, the center axis of the outlet of the axial flow fan 2 coincides with the center axis of the air supply pipe 1, the air inlet of the first air pipe 4 is connected with the air outlet of the axial flow fan 2, and the air outlet of the first air pipe 4 is located in the same vertical plane with the air outlet of the air supply pipe 1.

[0035] The first exhaust pipe includes a first tapered air pipe 5, a second tapered air pipe 7 and a first diffusion air pipe 8, the air outlet of the second tapered air pipe 7 and the air inlet of the first diffusion air pipe 8 are connected and nested in the first tapered air pipe 5, the outer wall of the second tapered air pipe 7 and the outer wall of the first diffusion air pipe 8 are both spaced from the inner wall of the first tapered air pipe 5, the air outlet of the first diffusion air pipe 8 is spaced from the air outlet of the first tapered air pipe 5, the air inlet of the first tapered air pipe 5 and the air inlet of the second tapered air pipe 7 are located in the same vertical plane and are tightly connected with the outlet end of the air supply device, and the first induced air port 6 is located on the side wall of the first tapered air pipe 5 along the length direction.

[0036] In this embodiment, the size of the air inlet of the first tapered air duct 5 is consistent with the size of the air outlet of the air supply duct 1, and the air inlet of the first tapered air duct 5 is connected to the air outlet of the air supply duct 1. The diameter of the first tapered air duct 5 gradually decreases along the length direction from the air inlet to the air outlet. A plurality of first induction air inlets 6 are symmetrically arranged on the left and right side walls of the first tapered air duct 5 along the length direction. The plurality of first induction air inlets 6 on the left and right sides of the first tapered air duct 5 are equally spaced. The size of the air inlet of the second tapered air duct 7 is consistent with the size of the air outlet of the first air duct 4, and the air inlet of the second tapered air duct 7 is connected to the air outlet of the first air duct 4. The diameter of the second tapered air duct 7 gradually decreases along the length direction from the air inlet to the air outlet, until the size of the air outlet of the second tapered air duct 7 is the same as the size of the air inlet of the first diffusion air duct 8. The air outlet of the second tapered air duct 7 is connected to the air inlet of the first diffusion air duct 8. The diameter of the first diffusion air duct 8 remains unchanged. After the second tapered air duct 7 is connected to the first diffusion air duct 8, the air outlet of the first diffusion air duct 8 is located inside the first tapered air duct 5. There is a distance between the air outlet of the first diffusion air duct 8 and the air outlet of the first tapered air duct 5, which facilitates the generation of negative pressure in the first tapered air duct 5 when high-speed airflow enters the first tapered air duct 5 through the first diffusion air duct 8. The air in the environment can enter the first tapered air duct 5 through the plurality of first induction air inlets 6 on the left and right sides of the first tapered air duct 5 and combine with the main airflow discharged from the first diffusion air duct 8, thereby increasing the air supply.

[0037] The second exhaust air duct is the second diffusion air duct 9. The air inlet of the second diffusion air duct 9 is connected to the air outlet of the first tapered air duct 5. The size and shape of the air inlet of the second diffusion air duct 9 are consistent with the size and shape of the air outlet of the first tapered air duct 5, respectively. The air outlet of the second diffusion air duct 9 is connected to the air inlet of the third exhaust air duct. The size and shape of the air outlet of the second diffusion air duct 9 are consistent with the size and shape of the air inlet of the third exhaust air duct, respectively.

[0038] In the embodiment, the air inlet and the air outlet of the second diffusion air duct 9 have the same diameter, the second diffusion air duct 9 is similar to the air supply duct 1, if the left and right sidewalls of the air supply duct 1 are vertical planes, since the air inlet of the first tapered air duct 5 is connected to the air outlet of the air supply duct 1, the left and right sidewalls of the first tapered air duct 5 are vertical planes, and the air inlet of the second diffusion air duct 9 is connected to the air outlet of the first tapered air duct 5, so the left and right sidewalls of the second diffusion air duct 9 are vertical planes; if the air supply duct 1 is a hollow cylindrical duct, the left and right sidewalls of the first tapered air duct 5 and the second diffusion air duct 9 are arc-shaped; the external airflow increased in the first tapered air duct 5 due to negative pressure is mixed with the main airflow, so that the airflow is in a turbulent state, the diameter of the second diffusion air duct 9 remains unchanged, the airflow flowing direction tends to the flowing direction of the main airflow through the second diffusion air duct 9, and the airflow gradually tends to a stable state in the second diffusion air duct 9, thereby facilitating the treatment of the airflow by the third exhaust air duct and maintaining the stability of the annular jet flow.

[0039] The third exhaust air duct includes a first expanding air duct 10 and a third diffusion air duct 12, the air inlet of the first expanding air duct 10 is connected to the air outlet of the second diffusion air duct 9, the air outlet of the first expanding air duct 10 is connected to the air inlet of the third diffusion air duct 12, the air outlet of the third diffusion air duct 12 is connected to the air outlet duct, and the second induced air inlets 11 are located on the sidewalls of the first expanding air duct 10 along the length direction.

[0040] In the embodiment, the diameter of the first expanding air duct 10 gradually increases along the length direction from the air inlet to the air outlet, the air inlet of the first expanding air duct 10 is connected to the air outlet of the second diffusion air duct 9, the air outlet of the first expanding air duct 10 is the same as the air inlet of the third diffusion air duct 12, the air outlet of the first expanding air duct 10 is connected to the air inlet of the third diffusion air duct 12, the diameter of the third diffusion air duct 12 along the length direction is the same, a plurality of second induced air inlets 11 are symmetrically arranged on the left and right sidewalls of the first expanding air duct 10 along the length direction, the plurality of second induced air inlets 11 on the left and right sidewalls of the first expanding air duct 10 are equally spaced, the airflow flowing out of the second diffusion air duct 9 enters the first expanding air duct 10, the main airflow flows along the center of the duct of the first expanding air duct 10, a negative pressure is generated around the main airflow, the external airflow is induced to flow into the first expanding air duct 10 through the plurality of second induced air inlets 11 on the left and right sidewalls of the first expanding air duct 10 and is mixed with the main airflow, the air supply amount is increased, and the airflow mixed in the first expanding air duct 10 gradually tends to be stable through the third diffusion air duct 12.

[0041] The air outlet duct is an adjustable nozzle 13, the adjustable nozzle 13 includes a fixed part 13-1 and an adjusting part 13-2, the fixed part 13-1 is connected to the air outlet of the third exhaust air duct, and the adjusting part 13-2 is slidingly connected to the outer sidewall of the fixed part 13-1 to facilitate changing the size of the air outlet of the adjustable nozzle 13.

[0042] In this embodiment, the air inlet of the fixed part 13-1 is connected with the air outlet of the third diffusion air pipe 12, the diameter of the fixed part 13-1 gradually decreases along the length direction from the air inlet to the air outlet, the outer side wall of the fixed part 13-1 is provided with four slide rails, the end of each slide rail along the length direction is provided with a clamping part, the end of each slide rail close to the third diffusion air pipe 12 is provided with a driving part, the adjusting part 13-2 is a hollow circular table, the hollow circular table is divided into four arc-shaped blades along the generatrix, the inner side wall of each arc-shaped blade is provided with a sliding block, the sliding block and the driving part are connected through a connecting rod mechanism, so that the driving part pushes the arc-shaped blade to slide forward or backward along the slide rail, the size of the air outlet of the adjustable nozzle 13 is adjusted, the driving part is electrically connected with the automatic control device 3, the working of the driving part is controlled through the automatic control device 3, the arc-shaped blade is driven to move forward or backward by the driving part, the purpose of changing the size of the air outlet of the adjustable nozzle 13 is achieved, and the driving part adopts a motor which can be purchased in the market.

[0043] Further, the outer side wall of the fixed part 13-1 is provided with four slide rails, the end of each slide rail along the length direction is provided with a clamping part, the adjusting part 13-2 includes a plurality of annular hollow circular tables, the plurality of annular hollow circular tables are mutually sleeved and slidably connected, each annular hollow circular table is evenly divided into four arc-shaped blades along the generatrix, the inner side wall of each arc-shaped blade is provided with a sliding block, the arc-shaped blade close to the fixed part 13-1 is slidably connected with the fixed part 13-1 through the sliding block, the outer side wall of each arc-shaped blade is provided with a slide rail, the end of each slide rail along the length direction is provided with a clamping part, the adjacent two arc-shaped blades are slidably connected through the sliding block and the slide rail, the end of each slide rail is provided with a driving part, the sliding block is pushed to move forward or backward along the slide rail through the automatic control device 3 controlling the driving part, so that the size of the air outlet of the adjustable nozzle 13 reaches the target caliber, each driving part is electrically connected with the automatic control device 3, the working of different driving parts is controlled through the automatic control device 3, so as to achieve the purpose of adjusting the size and direction of the air outlet.

[0044] The induced jet flow ventilation system further includes a plurality of gas monitoring systems, each of which is in communication connection with the automatic control device 3.

[0045] In this embodiment, the gas monitoring system selects a portable gas detector of RKI GX-2009 type, a plurality of gas monitoring systems are installed in the welding pipeline at equal intervals, the gas monitoring system collects and analyzes the gas in the welding pipeline and then transmits the analysis result to the automatic control device 3, at the same time, the gas monitoring system judges whether to trigger an alarm according to the set gas component concentration, the automatic control device 3 adjusts the power of the axial flow fan 2 and the size and direction of the air outlet of the adjustable nozzle 13 through the received information, so as to achieve the purpose of adjusting the gas concentration in the welding pipeline, guarantee the safety of the operating personnel and improve the welding effect.

[0046] The first and second induction air inlets 6 and 11 are circular holes.

[0047] In the embodiment, the first and second induction air inlets 6 and 11 are circular holes, which facilitates the flow of air.

[0048] In use, the plurality of gas monitoring systems are installed at intervals in the pipeline to be welded, and the induction jet ventilation system is pushed into the pipeline to be welded at the position to be welded, so as to increase the effective distance of air supply; during the welding operation, the axial flow fan 2 is in operation, and the external air is supplied into the first tapered air pipe 5 through the axial flow fan 2, the first air pipe 4, the second tapered air pipe 7 and the first diffusion air pipe 8, so that a negative pressure zone is formed at the wall of the first tapered air pipe 5, and then the external air is driven to flow into the first tapered air pipe 5 through the first induction air inlet 6 and is combined with the main air flow, so as to increase the air supply amount of the main air flow; the combined main air flow gradually stabilizes in the second diffusion air pipe 9, and when the main air flow flows into the first gradually expanding air pipe 10, a negative pressure zone is formed along the first gradually expanding air pipe 10 due to the flow of the main air flow along the center of the pipeline, so that the surrounding air is driven to flow into the first gradually expanding air pipe 10 through the second induction air inlet 11 and is combined with the main air flow, so as to increase the air supply amount in the pipeline; after the main air flow passes through the third diffusion air pipe 12, the gas flows into the pipeline to be welded through the annular jet flow at the adjustable nozzle 13, since the jet flow is ejected from the nozzle, the initial speed is high, the surrounding air is driven to flow along the main air flow, and then the entire gas in the pipeline to be welded is driven to flow, so as to achieve the ventilation effect; at the same time, the plurality of gas monitoring systems in the pipeline to be welded continuously detect the gas composition in the pipeline to be welded and transmit the detection information to the automatic control device 3, the automatic control device 3 adjusts the power of the axial flow fan 2 and the size and direction of the air outlet of the adjustable nozzle 13 based on the received gas composition, so as to quickly adjust the gas concentration in the pipeline to be welded, and ensure the personal safety and work efficiency of the operator.

[0049] The above is only a preferred embodiment of the present application, and does not limit the present application, any simple modification, change and equivalent structure change of the above embodiment according to the technical essence of the present application still belong to the protection scope of the technical scheme of the present application.

Claims

1. An induced jet ventilation system for assisting in the exhaust of harmful gases, characterized by: The invention comprises an air supply device, an exhaust pipe and an air outlet pipe, the outlet end of the air supply device is connected to the exhaust pipe, the end of the exhaust pipe away from the air supply device is connected to the air outlet pipe for adjusting the size of the air outlet and the direction of the air outlet, the exhaust pipe comprises a first exhaust pipe, a second exhaust pipe and a third exhaust pipe, the outlet end of the first exhaust pipe is connected to the inlet end of the second exhaust pipe, the outlet end of the second exhaust pipe is connected to the inlet end of the third exhaust pipe, the diameter of the inlet end of the first exhaust pipe is larger than the diameter of the outlet end, the first exhaust pipe A plurality of first induced air vents (6) are symmetrically provided on the left and right side walls of the tube, and the plurality of first induced air vents (6) are arranged at equal intervals. The diameter of the inlet end of the second exhaust duct is consistent with the diameter of the outlet end of the first exhaust duct, and the diameter of the outlet end of the second exhaust duct is consistent with the diameter of the inlet end of the third exhaust duct. The diameter of the outlet end of the third exhaust duct is larger than the diameter of the inlet end. A plurality of second induced air vents (11) are symmetrically provided on the left and right side walls of the third exhaust duct, and the plurality of second induced air vents (11) are arranged at equal intervals.

2. An induced jet ventilation system for assisting in exhausting harmful gases according to claim 1, characterized in that: The air supply device comprises an air supply pipe (1), an axial flow fan (2), an automatic control device (3) and a first air duct (4); the axial flow fan (2) and the first air duct (4) are both installed in the air supply pipe (1); the automatic control device (3) is installed on the side wall of the air supply pipe (1) and is electrically connected to the axial flow fan (2); the air inlet of the first air duct (4) is connected to the air outlet of the axial flow fan (2); and the air outlet of the first air duct (4) extends to the air outlet of the air supply pipe (1).

3. The induced jet ventilation system for assisting in exhausting harmful gases according to claim 2, characterized in that: The top and bottom of the air supply pipe (1) are both arched structures, the arched structure at the top of the air supply pipe (1) protrudes upward, and the arched structure at the bottom of the air supply pipe (1) protrudes downward, and the left and right side walls of the air supply pipe (1) are both perpendicular to the horizontal plane.

4. The induced jet ventilation system for assisting in exhausting harmful gases according to claim 1, characterized in that: The first exhaust duct comprises a first converging duct (5), a second converging duct (7) and a first diffusion duct (8); the air outlet of the second converging duct (7) and the air inlet of the first diffusion duct (8) are connected and then nested in the first converging duct (5); a distance is left between the outer wall of the second converging duct (7) and the outer wall of the first diffusion duct (8) and the inner wall of the first converging duct (5); a distance is left between the air outlet of the first diffusion duct (8) and the air outlet of the first converging duct (5); the air inlet of the first converging duct (5) and the air inlet of the second converging duct (7) are located in the same vertical plane and are tightly connected to the outlet end of the air supply device; the first induced air outlet (6) is located on the side wall of the first converging duct (5) along the length direction.

5. The induced jet ventilation system for assisting in exhausting harmful gases according to claim 4, characterized in that: The second exhaust duct is a second diffuser duct (9), the air inlet of the second diffuser duct (9) is connected to the air outlet of the first gradually converging duct (5), the size and shape of the air inlet of the second diffuser duct (9) are respectively consistent with the size and shape of the air outlet of the first gradually converging duct (5), the air outlet of the second diffuser duct (9) is connected to the air inlet of the third exhaust duct, the size and shape of the air outlet of the second diffuser duct (9) are respectively consistent with the size and shape of the air inlet of the third exhaust duct.

6. The induced jet ventilation system for assisting in exhausting harmful gases according to claim 5, characterized in that: The third exhaust duct comprises a first gradually diverging air duct (10) and a third diffuser air duct (12); the air inlet of the first gradually diverging air duct (10) is connected to the air outlet of the second diffuser air duct (9); the air outlet of the first gradually diverging air duct (10) is connected to the air inlet of the third diffuser air duct (12); the air outlet of the third diffuser air duct (12) is connected to the air outlet duct; the second induced air outlet (11) is located on the side wall of the first gradually diverging air duct (10) along the length direction.

7. The induced jet ventilation system for assisting in exhausting harmful gases according to claim 1, characterized in that: The air outlet pipe is an adjustable nozzle (13), and the adjustable nozzle (13) comprises a fixed portion (13-1) and an adjusting portion (13-2). The fixed portion (13-1) is connected to the air outlet of the third air outlet pipe, and the adjusting portion (13-2) is slidably connected to the outer side wall of the fixed portion (13-1) to facilitate changing the size of the air outlet of the adjustable nozzle (13).

8. The induced jet ventilation system for assisting in exhausting harmful gases according to claim 2, characterized in that: The induced jet ventilation system further comprises a plurality of gas monitoring systems, each of which is in communication connection with the automatic control device (3).

9. The induced jet ventilation system for assisting in exhausting harmful gases according to claim 1, characterized in that: The first induced air outlet (6) and the second induced air outlet (11) are both circular holes.

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