Gas mixing box capable of adjusting concentration

Abstract

The utility model provides a concentration-adjustable gas mixing box which comprises a box body, and the side surface of the box body is communicated with a first gas inlet pipe, a second gas inlet pipe and a gas outlet pipe; a motor is arranged on the box cover; comprising a first stirring device, the first stirring device comprises a first transmission shaft, the first transmission shaft is vertically arranged, and the top end of the first transmission shaft is coaxially and fixedly connected with the output end of a motor; fan blades are mounted on the first transmission shaft and blow air downwards; comprising a second stirring device, the second stirring device comprises a second transmission shaft, the second transmission shaft is transversely arranged, and an impeller is coaxially arranged on the second transmission shaft; the bottom end of the first transmission shaft is in meshing transmission connection with one end of the second transmission shaft through a pair of bevel gear sets; comprising a gas concentration detector, and the collection end of the gas concentration detector is arranged in a box body. The technical problems that in the prior art, the gas mixing concentration adjusting precision is not high, and mixing is not uniform due to gas layering are solved.

Description

Technical Field

[0001] This utility model relates to the field of physics, particularly to measurement and testing technology, and further to experimental apparatus for mixed gases, especially an adjustable concentration gas mixing chamber. Background Technology

[0002] Mixed gas experiments are commonly used to determine the effects of mixed gases present in an indoor environment on electrical and electronic product components, systems, and materials. Mixed gas experiments require the use of a mixing chamber to mix the gases.

[0003] Existing technologies typically use venturi tubes or gas mixing chambers for gas mixing, but these methods have the following drawbacks:

[0004] 1. When using a venturi tube to rapidly mix two gases, the accuracy of the gas mixture concentration is not high, making it difficult to meet the requirements of highly sensitive gas experiments.

[0005] 2. When using a gas mixing chamber to mix gases, two gases are input into the mixing chamber for mixing. However, the heavier gas will quickly settle to the bottom of the chamber, causing gas stratification, resulting in uneven mixing and poor quality of the output gas. Utility Model Content

[0006] The purpose of this invention is to provide an adjustable concentration gas mixing box, which aims to solve the technical problems of low gas mixing concentration adjustment accuracy and uneven mixing caused by gas stratification in the prior art.

[0007] An adjustable concentration gas mixing chamber includes a chamber body with a cover at the top opening; a first inlet pipe, a second inlet pipe, and an outlet pipe are connected to the side of the chamber body; a motor is mounted on the cover, with the output end of the motor passing through the cover and disposed inside the chamber body; a first stirring device includes a first drive shaft, which is vertically oriented and its top end is coaxially fixed to the output end of the motor; a fan blade is mounted on the first drive shaft, and the first drive shaft and the fan blade are coaxially fixed, with the fan blade blowing air downwards; a second stirring device includes a second drive shaft, which is horizontally oriented and has an impeller coaxially mounted on it; a bushing is fitted on the second drive shaft, and a support rod is provided at the bottom of the bushing, the support rod being fixed to the bottom of the chamber body; the bottom end of the first drive shaft and one end of the second drive shaft are connected by a pair of bevel gears; and a gas concentration detector is included, with its acquisition end disposed inside the chamber body.

[0008] Furthermore, it includes a Venturi tube disposed within the housing. The Venturi tube includes an air inlet, a mixing port, and an air outlet. One end of the main channel of the Venturi tube is the air inlet, and the other end is the air outlet. The mixing port is connected to the narrow section of the main channel. The first air inlet pipe is connected to the air inlet, the second air inlet pipe is connected to the mixing port, and the air outlet is connected to the interior of the housing.

[0009] Furthermore, the impeller includes an impeller core and a plurality of blade seats evenly arranged around the axis of the impeller core. The impeller core is coaxially fixed to the second drive shaft. The blade seats are disposed on the outer periphery of the impeller core. Each blade seat has a groove facing the axis. A telescopic plate is slidably connected in each groove. The bottom of the telescopic plate is connected to the bottom of the groove by a spring. A limit strip is provided on the bottom edge of the telescopic plate. The limit strip abuts against the inner side of the groove opening.

[0010] Furthermore, the number of impellers is two or more.

[0011] Compared with existing technologies, the advantages of this invention are positive and obvious:

[0012] 1. The venturi tube of this utility model is used for preliminary mixing. The first stirring device blows the gas from the top of the box downward to the bottom of the box, and the impeller of the second stirring device is set horizontally to stir the gas above and below the box, thereby avoiding uneven mixing caused by gas stratification.

[0013] 2. The impeller blades of this utility model are retractable blades. The greater the centrifugal force, the longer the blades extend, thereby adjusting the stirring range according to the impeller speed, thus stirring more gas in the upper and lower chambers and increasing the concentration of the mixed gas. Attached Figure Description

[0014] Figure 1 A schematic diagram of the external structure of an embodiment of this utility model.

[0015] Figure 2 A schematic diagram of the internal structure of an embodiment of this utility model.

[0016] Figure 3 A schematic diagram of the impeller blades in an embodiment of this utility model when they are not elongated.

[0017] Figure 4 A schematic diagram of the structure of the impeller blades when they are elongated in an embodiment of this utility model.

[0018] Figure 5 A schematic diagram showing the connection between the first and second air intake pipes and the venturi tube in an embodiment of this utility model.

[0019] In the diagram: 1. Housing; 2. Housing cover; 3. First drive shaft; 4. Bushing; 5. Impeller; 501. Blade holder; 502. Telescopic plate; 503. Slide groove; 504. Spring; 505. Limiting strip; 6. Bevel gear set; 7. Support rod; 8. Second drive shaft; 9. Fan blade; 10. Motor; 11. First air inlet pipe; 12. Second air inlet pipe; 13. Venturi tube; 14. Air outlet pipe; 15. Gas concentration detector. Detailed Implementation

[0020] The following embodiments will further illustrate the present invention, but are not intended to limit the present invention.

[0021] like Figures 1 to 5 As shown, this embodiment provides an adjustable concentration gas mixing chamber for mixing standard gas and nitrogen.

[0022] The enclosure includes a box body 1, with a box cover 2 at the top opening of the box body 1. The bottom edge of the box cover 2 is engaged with the top edge of the box body 1. A sealing ring is provided at the connection between the box cover 2 and the box body 1, which facilitates opening and maintenance while improving the sealing effect.

[0023] A first air inlet pipe 11 and a second air inlet pipe 12 are connected and installed on one side of the housing 1, and an air outlet pipe 14 is connected and installed on the other side of the housing 1. The first air inlet pipe 11 introduces nitrogen into the housing 1, the second air inlet pipe 12 introduces standard gas into the housing 1, and the mixed gas is output from the air outlet pipe 14.

[0024] The system includes a Venturi tube 13, which is installed inside the housing 1. The Venturi tube 13 includes an inlet, a mixing port, and an outlet. The mixing port is located at the narrowest point of the Venturi tube 13. A first inlet pipe 11 connects to the inlet, and a second inlet pipe 12 connects to the mixing port, achieving preliminary mixing of nitrogen and standard gas. The mixture is then delivered to the housing 1 through the outlet. The mixing process using the Venturi tube 13 is conventional existing technology, and its structure and principle will not be described in detail here.

[0025] The gas initially mixed through the Venturi tube 13 has a difficult-to-control mixing ratio and cannot be used directly. Therefore, the mixed gas needs to be mixed a second time in the chamber 1 to further adjust the gas mixing ratio and output the gas of the required concentration.

[0026] A motor 10 is mounted on the cover 2, and the output end of the motor 10 passes through the cover 2 and is located inside the housing 1. The motor 10 is connected to a speed controller, which can control the speed of the motor 10.

[0027] The device includes a first stirring device, which includes a first drive shaft 3. The first drive shaft 3 is vertically arranged, and its top end is coaxially fixed to the output end of the motor 10. A fan blade 9 is mounted on the first drive shaft 3. The fan blade 9 has a mounting hole in its center. After the first drive shaft 3 is inserted into the mounting hole, it is coaxially fixed to the fan blade 9. The first drive shaft 3 serves as the rotating shaft of the fan blade 9, driving the fan blade 9 to rotate. When the motor 10 is working, the fan blade 9 blows air downwards, thereby blowing the lighter gas at the top of the box 1 downwards to the bottom of the box 1, where it mixes with the heavier gas.

[0028] The system includes a second stirring device, which comprises a second drive shaft 8 arranged laterally. Two impellers 5 are coaxially fixed to the second drive shaft 8. A bushing 4 is fitted onto the second drive shaft 8, and a support rod 7 is located at the bottom of the bushing 4. The support rod 7 is fixed to the bottom of the housing 1 for fixation. The housing 1 contains two impellers 5, located on opposite sides of the bushing. The horizontally arranged impellers of the second stirring device agitate the gas above and below the housing 1, thus preventing uneven mixing caused by gas stratification.

[0029] The bottom end of the first drive shaft 3 and one end of the second drive shaft 8 are connected by a pair of bevel gears 6, so that the first drive shaft 3 and the second drive shaft 8 can be driven to rotate simultaneously by a motor 10.

[0030] The impeller 5 includes an impeller core and a plurality of blade seats 501 evenly arranged around the axis of the impeller core. The impeller core is coaxially fixed to the second drive shaft 8. The blade seats 501 are fixed to the outer periphery of the impeller core. The length direction of the blade seats 501 is parallel to the axial direction of the impeller core. Each blade seat 501 has a groove 503 facing the axis. A telescopic plate 502 is slidably connected in each groove 503. The telescopic plate 502 and the blade seat 501 are set as a sliding pair along the radial direction of the impeller core. The bottom of the telescopic plate 502 is connected to the blade seat 501 at the bottom of the groove 503 by three springs 504. The springs 504 bias the telescopic plate 502 toward the axis of the impeller core. A limit strip 505 is provided on the bottom edge of the telescopic plate 502. The limit strip 505 abuts against the locking blocks on the inner side of both ends of the opening of the groove 503.

[0031] When the impeller 5 rotates, the telescopic plate 502 extends out of the impeller 5 seat under the action of centrifugal force. The faster the rotation speed, the longer the extension length, thereby increasing the stirring range of the impeller 5 according to the rotation speed, driving the gas at the top and bottom of the box 1 to stir and mix, and increasing the concentration of the mixed gas.

[0032] The system includes a gas concentration detector 15. In this embodiment, the gas concentration detector 15 is a GD-100 fixed gas detector with a display screen. In other embodiments, it can be replaced with a detection element that meets the specific needs of the gas. The acquisition end of the gas concentration detector 15 is located inside the housing 1. The gas concentration detector 15 includes a display screen, which is located on the outside of the housing 1. The real-time concentration of the gas can be viewed intuitively through the display screen.

[0033] How to use this embodiment:

[0034] This embodiment is used to extract a mixture of nitrogen and standard gas, which is applicable to scenarios where multiple mixed gases of different concentrations are required in a short period of time, such as precision testing or debugging of gas alarms.

[0035] Nitrogen is introduced through the first intake pipe 11 and standard gas is introduced through the second intake pipe 12. The nitrogen and standard gas are initially mixed through the venturi tube 13 and then delivered to the housing 1 through the outlet of the venturi tube 13.

[0036] When the motor 10 is turned on, the motor 10 drives the first transmission shaft 3 to rotate, and the fan blade 9 blows air downwards, thereby blowing the lighter gas at the top of the box 1 downwards to the bottom of the box 1 and mixing it with the heavier gas.

[0037] The bottom end of the first drive shaft 3 and one end of the second drive shaft 8 are connected by a pair of bevel gears 6, so that the first drive shaft 3 and the second drive shaft 8 can be driven to rotate simultaneously by a motor 10.

[0038] The second drive shaft 8 rotates, thereby driving the two impellers 5 to rotate. The telescopic plate 502 extends out from the impeller 5 seat under the action of centrifugal force. The faster the rotation speed of the second drive shaft 8, the longer the extension length of the telescopic plate 502, thereby increasing the stirring range of the impeller 5 according to the rotation speed, driving the gas at the top and bottom of the box 1 to stir and mix, and increasing the concentration of the mixed gas.

[0039] The real-time gas concentration is observed on the display screen of the gas concentration detector 15. When the real-time concentration is lower than the required concentration, the speed of the motor 10 is increased by the speed control unit, the speed of the fan blade 9 and the impeller 5 is increased, the airflow of the fan blade 9 is increased, and the telescopic plate 502 of the impeller 5 is further extended, thereby increasing the mixing range and achieving an increase in gas concentration; conversely, when the real-time concentration is higher than the required concentration, the speed of the motor 10 is reduced, the airflow is reduced, the telescopic plate 502 of the impeller 5 is retracted, thereby reducing the output gas concentration.

[0040] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gas mixing box with adjustable concentration, comprising a box body (1), wherein a box cover (2) is arranged at the top opening of the box body (1), characterized in that: a first gas inlet pipe (11), a second gas inlet pipe (12) and a gas outlet pipe (14) are in communication with the side of the box body (1); a motor (10) is arranged on the box cover (2), and the output end of the motor (10) is arranged in the box body (1) through the box cover (2); a first stirring device is arranged, which comprises a first transmission shaft (3) arranged vertically, the top end of the first transmission shaft (3) is coaxially fixedly connected with the output end of the motor (10), a fan blade (9) is arranged on the first transmission shaft (3) and is coaxially fixedly connected with the first transmission shaft (3), and the blowing direction of the fan blade (9) is downward; a second stirring device is arranged, which comprises a second transmission shaft (8) arranged transversely, an impeller (5) is coaxially arranged on the second transmission shaft (8), an axle sleeve (4) is sleeved on the second transmission shaft (8), a supporting rod (7) is arranged at the bottom of the axle sleeve (4) and is fixedly connected with the bottom of the box body (1); the bottom end of the first transmission shaft (3) is in meshing transmission connection with one end of the second transmission shaft (8) through a pair of bevel gears (6); and a gas concentration detector (15) is arranged, and the collection end of the gas concentration detector (15) is arranged in the box body (1).

2. The gas mixing box with adjustable concentration according to claim 1, characterized in that: a Venturi tube (13) is arranged in the box body (1), the Venturi tube (13) comprises an air inlet, a mixing port and an air outlet, one end of the main channel of the Venturi tube (13) is the air inlet, the other end is the air outlet, the mixing port is in communication with the narrow part of the main channel, the first gas inlet pipe (11) is in communication with the air inlet, the second gas inlet pipe (12) is in communication with the mixing port, and the air outlet is in communication with the inside of the box body.

3. The gas mixing box with adjustable concentration according to claim 1, characterized in that: the impeller (5) comprises an impeller core and a plurality of blade seats (501) arranged uniformly around the axis of the impeller core, the impeller core is coaxially fixedly connected with the second transmission shaft (8), the blade seats (501) are arranged at the outer periphery of the impeller core, a sliding groove (503) towards the axis is formed in each blade seat (501), a flexible piece (502) is slidably connected in each sliding groove (503), the bottom of the flexible piece (502) is connected with the groove bottom of the sliding groove (503) through a spring (504), a limiting strip (505) is arranged at the bottom edge of the flexible piece (502), and the limiting strip (505) abuts against the inner side of the opening of the sliding groove (503).

4. The gas mixing box with adjustable concentration according to claim 1, characterized in that: the number of the impellers (5) is more than two. ​ ​ ​ ​ ​ ​ ​ ​ ​

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