CN211159848U

CN211159848U - High-speed discharge device for mechanical air exhaust in laboratory

Info

Publication number: CN211159848U
Application number: CN201920244939.0U
Authority: CN
Inventors: 赵侠; 李顺
Original assignee: China IPPR International Engineering Co Ltd
Current assignee: China IPPR International Engineering Co Ltd
Priority date: 2019-02-27
Filing date: 2019-02-27
Publication date: 2020-08-04
Anticipated expiration: 2029-02-27

Abstract

The utility model provides a high-speed discharging equipment for laboratory machine is aired exhaust, include: an air exhaust vertical pipe (1), wherein the air exhaust vertical pipe (1) is a gradual change pipe with a continuous variable cross section or a pipeline with a sectional variable cross section structure, one end of the air exhaust vertical pipe (1) is arranged on the ground, the other end of the air exhaust vertical pipe penetrates through a roof surface layer to extend outdoors, one side of an indoor part is provided with a three-way pipe (2), the port of the bypass is connected with an exhaust unit, a steel wire mesh (3) is arranged in the port, a water and snow collecting bin (4) is arranged at the bottom of an exhaust vertical pipe (1), a water seal and drainage device (5) is arranged in the air exhaust device, an arc-shaped sealed air exhaust vertical pipe cleaning port (6) is arranged at the lower end of an air exhaust vertical pipe (1), one end of the air exhaust vertical pipe (1) is installed on an air exhaust vertical pipe concrete foundation (7), the outer side of the part, extending out of the room, of the air exhaust vertical pipe (1) is coated with a heat insulation layer (8), a galvanized steel plate is adopted as a protective layer (9) on the outer side of the heat insulation layer (8), and a conical rain cover (10) is arranged at the position, connected.

Description

High-speed discharge device for mechanical air exhaust in laboratory

Technical Field

The utility model belongs to the technical field of the laboratory is aired exhaust, concretely relates to high-speed machinery exhaust device who contains pollutant.

Background

The prior art is to laboratory mechanical exhaust system's outdoor discharge mode, no matter general air exhaust, still contain the laboratory that the national standard has the limited pollutant composition and exhaust, and the measure of taking has several kinds: 1) a straight pipe with a constant cross section and a conical blast cap; 2) a straight pipe with a uniform cross section and a circular umbrella-shaped hood; 3) a straight pipe with a uniform cross section and a 90-degree elbow at the top; 4) a straight pipe with a uniform cross section and a 135-degree lower elbow at the top; 5) equal section straight pipe + 180 degree lower elbow at top. The measures 1) and 2) can be seen from the national building standard design atlas K1 (below), 96K150-3 circular umbrella type blast caps and 96K150-2 conical type blast caps; and measures 3), 4) and 5) are present in the actual engineering example.

The prior art has the following defects:

1. measures 1) and 2) in the prior art, the top end of the air exhaust vertical pipe is provided with an air cap which has a blocking effect on the upward air exhaust flow, thereby reducing the diffusion speed of the air exhaust containing pollutants and reducing the pollutant emission height;

2. in the prior art, the measures 3) and 4) are adopted, the top end of the air exhaust vertical pipe is provided with a 90-degree elbow, a 135-degree elbow or a 180-degree elbow, the original upward exhaust airflow changes the direction and changes into lateral exhaust or even downward exhaust, and the pollutant emission height is seriously reduced;

3. all the measures make the pollutant discharge factory boundary have higher concentration.

4. In all the above methods, under normal meteorological conditions, the height from the pollutant discharge port to the outlet of the air pipe is usually about 10 times of the pipe diameter. The height is about 9.5-16 m when the exhaust air volume is 10000-30000 m3/h and the air speed of the air pipe is 6-8 m/s. Even if the exhaust air is treated to reach the discharge standard, the diffusion height of the exhaust air cannot reach the value under the adverse meteorological conditions.

According to the national atmospheric environmental quality Standard (GB3095-2012), laboratories belong to the second class of areas of environmental air functional zoning, including SO₂、NOx、O₃PM2.5, etc. H2S, NH3 and the like in the emission standard of malodorous pollutants (GB14554-93) are pollutants which are limited to be emitted by the nation and are pollutants which are often contained in exhaust air of a laboratory. Therefore, there is a need to design a high-speed discharge device for laboratory mechanical exhaust with better discharge efficiency.

SUMMERY OF THE UTILITY MODEL

In order to overcome the above-mentioned problem that prior art exists, the utility model provides a high-speed discharging equipment for laboratory machine is aired exhaust, include: the air exhaust vertical pipe (1) is a gradual change pipe with a continuous variable cross section or a pipeline with a sectional variable cross section structure so as to change the cross section of the air exhaust vertical pipe (1), one end of the air exhaust vertical pipe (1) is arranged on the ground, and the other end of the air exhaust vertical pipe (1) penetrates through a roof surface layer and extends out of the room.

Preferably, one side of the indoor part of the exhaust vertical pipe (1) is provided with a three-way pipe (2), and a bypass port of the three-way pipe (2) is connected with the exhaust unit and receives air to be exhausted from the exhaust unit.

Preferably, a steel wire mesh (3) is arranged in the three-way pipe (2).

Preferably, the bottom of the exhaust vertical pipe (1) is provided with a water and snow collecting bin (4).

Preferably, a water seal and a drainage device (5) are arranged in the water and snow collecting bin (4).

Preferably, the lower end of the air exhaust vertical pipe (1) is provided with an arc-shaped sealed air exhaust vertical pipe cleaning opening (6).

Preferably, one end of the air exhaust vertical pipe (1) which is arranged on the ground is arranged on an air exhaust vertical pipe concrete foundation (7).

Preferably, the outer side of the part of the air exhaust vertical pipe (1) extending out of the room is coated with an insulating layer (8).

Preferably, galvanized steel sheets are adopted as the protective layers (9) on the outer sides of the heat insulation layers (8).

Preferably, a conical rain cover (10) is arranged at the position where the air exhaust vertical pipe (1) is connected with a roof surface layer.

The utility model discloses compare prior art's beneficial effect:

the wind speed of the wind pipe is improved to 12m/s through the variable cross section of the vertical air exhaust pipe; the section of the air pipe is changed by adopting a gradual change pipe, and the length and the angle of the gradual change pipe are obtained by calculation, so that the minimum resistance of the air pipe is ensured; the air exhaust diffusion speed is improved by improving the air speed at the outlet of the air exhaust pipe; the variable cross-section exhaust vertical pipe is installed on the ground, when the exhaust air volume is 10000-30000 m3/h and the air speed of the air pipe is 6-8 m/s, the diffusion height of the exhaust air containing pollutants in a laboratory is increased by 28% -54%, the cost is only increased slightly, in addition, all shielding and blocking of the exhaust pipe are eliminated, so that the diffusion speed and the diffusion height of the exhaust air containing pollutants are increased, the factory boundary concentration of pollutant emission is effectively reduced, and the improvement of the environment of a laboratory area is facilitated.

The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the present invention will be described in detail hereinafter, by way of illustration and not by way of limitation, with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. The objects and features of the present invention will become more apparent in view of the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic structural view of a high-speed exhaust device for laboratory mechanical ventilation according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an isopycnic gas jet velocity field according to an embodiment of the present invention.

Detailed Description

The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings, which are not intended to limit the scope of the invention.

Referring to fig. 1, a high-speed discharge device for laboratory mechanical ventilation, comprising: the air exhaust vertical pipe 1 is a gradual change pipe with a continuous variable cross section or a pipeline with a sectional variable cross section structure so as to change the cross section of the air exhaust vertical pipe 1, one end of the air exhaust vertical pipe 1 is installed on the ground, and the other end of the air exhaust vertical pipe 1 penetrates through a roof surface layer and extends out of the room. One side of the indoor part of the vertical exhaust pipe 1 is provided with a three-way pipe 2, and the port of the bypass of the three-way pipe 2 is connected with an exhaust unit and receives air to be exhausted from the exhaust unit. The steel wire mesh 3 is arranged in the three-way pipe 2, in the embodiment, SS314 stainless steel is adopted to manufacture the steel wire mesh 3, the aperture is 20 x 20, and the steel wire mesh is used for an exhaust system to intercept outdoor birds and insects and foreign matters and prevent the birds and the foreign matters from entering the system to cause damage. The vertical air exhaust pipe 1 is a gradient pipe to change the section of the vertical air exhaust pipe, and the length and the angle of the gradient pipe and the length and the angle of the three-way pipe are obtained by a conventional numerical calculation method to ensure that the resistance of the air pipe is minimum. Set up catchment collection snow storehouse 4 bottom the riser of airing exhaust 1, set up water seal and drainage device 5 in catchment collection snow storehouse 4, prevent to install the riser of airing exhaust on the ground because the erosion life of water and snow reduces, and prevent that the tuber pipe from leaking gas and guarantee the gas tightness of tuber pipe, be used for discharging the water that will dissolve nearby to the lower water spot simultaneously, drainage device 5 is the riser drain pipe of airing exhaust in this embodiment, the pipe diameter is DN25, of course technical staff in the art also can adopt the known active or passive drainage device of other prior art according to the volume of discharging and the requirement of time, all be in the utility model discloses a protection within range. The lower end of the air exhaust vertical pipe 1 is provided with an arc-shaped sealed air exhaust vertical pipe cleaning port 6, so that air pipes can be cleaned conveniently and regularly, the cleanness of the air pipes is kept, and the service life of the discharging device is prolonged. One end of the air exhaust vertical pipe 1 which is installed in a floor mode is installed on the air exhaust vertical pipe concrete foundation 7 and isolated from the ground, so that air pipe fixation, vibration isolation and drainage are facilitated, the emission efficiency is improved, and the service life of the device is prolonged. The outer side of the part, extending out of the air exhaust vertical pipe 1, of the air exhaust vertical pipe is coated with the heat insulation layer 8, and the glass wool felt is used as the heat insulation layer (8) in the embodiment, so that the air pipe is prevented from being frozen, the wind erosion and the environmental influence are prevented, and the service life of the main body of the air exhaust vertical pipe 1 is prolonged. The outer side of the heat preservation layer 8 adopts a galvanized steel sheet with the thickness of 0.5mm as a protective layer 9, so that the abrasion and erosion of the environment wind erosion or hard objects to the main body of the air exhaust vertical pipe 1 are prevented. The conical rain cover 10 is arranged at the position where the vertical air exhaust pipe 1 is connected with the roof surface layer, so that rainwater is prevented from entering the room. The detailed method for making the heat-insulating pipeline penetrate through the roof can refer to construction professional drawings, and belongs to a scheme which can be directly obtained by a person skilled in the art.

The physical basis of the practice of the present invention is the jet phenomenon, so-called jet (jet), which means that the fluid is ejected from a pipe orifice, slit, or is mechanically propelled and flows with a jet of fluid mixed with the surrounding fluid. The high reynolds number jets often encountered are generally free turbulent flows without solid wall constraints. This turbulent jet is continually expanding by entrainment of surrounding fluid through active turbulent mixing at the boundary and flows downstream. The jet flow is widely applied to many technical fields such as water pumps, steam pumps, ventilators, chemical equipment, jet planes and the like. Gas jets, also called gas turbulence jets. A schematic diagram of the isopycnic gas jet velocity field is shown in fig. 2. When fluid is injected into a static environment, a discontinuous surface with different speeds exists between the fluid and the surrounding static fluid, the discontinuous surface is generally disturbed inevitably, loses stability to generate vortex, sucks the surrounding fluid into jet flow, and simultaneously moves, deforms and splits continuously to generate turbulent motion, and the influence of the turbulent motion gradually develops towards the inner side and the outer side to form a freely turbulent motion mixed layer. Due to the transverse transfer of momentum, the involved fluid obtains momentum and flows forwards along with the original jet flow, the original fluid momentum is reduced and loses speed, and a certain speed gradient is formed. As a result of entrainment and mixing, the jet cross section is continuously enlarged, the flow velocity is continuously reduced, and the flow rate is increased along the way. Jet motion is generally affected by initial momentum or buoyancy, pure jets and plumes being the extremes of jets. If the density of the ambient fluid is the same everywhere, then the jet is a uniform ambient jet. If the ambient fluid density is not uniform along the vertical, the buoyant jets are laminar ambient force jets. A uniform ambient jet process where the ambient fluid density is equal to the leaked natural gas density, as shown in figure 2. The straight lines OB and OC are the outer boundaries of the jet flow, the intersection point O is the pole of the jet flow on the boundary of the jet flow, and the advancing movement speed is zero. The boundaries AD, ED at which the jet spreads towards the surrounding air molecular micelles are also straight lines. In the ADE region, the pure natural gas velocity is equal to the orifice leakage velocity, referred to as the jet core region. The angle of the outer boundary of the jet is called the opening angle of the jet. Angle of jet core zone boundary: is the jet core contraction angle. The jet cross section FG passing through point D is called the transition section. Before this section, the axial velocity Wm of the jet is kept constant and equal to the initial velocity W0, and then the axial velocity is gradually reduced. The section average velocity W decreases as S increases. The transition section is referred to as the initial section before and as the basic section after. The starting section length S0 and the pole depth h0 of the turbulent free jet are both related to the orifice radius r. When the temperature and density of the ambient air is different from the leaking natural gas, it can be considered as an unequal density jet. The trajectory of the non-iso-density jet is complex, when gravity differences bend the jet. The density of the leaking gas is greater than the density of the ambient air and the jet is generally curved downwardly and conversely curved upwardly. If the jet emerges vertically upwards, the difference in gravity only slightly changes the opening angle and the core contraction angle of the jet, and does not distort the velocity distribution in the section nor bend the jet, in which case the opening angle and the contraction angle increase if the density of the leaking air flow is greater than that of the surrounding air, and conversely the angle decreases. The distance the jet is acting on is related to the jet exit velocity, exit flow, exit size and exit momentum.

The utility model improves the wind speed of the wind pipe to 12m/s through the variable cross section of the air exhaust vertical pipe; the section of the air pipe is changed by adopting a gradual change pipe, and the length and the angle of the gradual change pipe are obtained by calculation, so that the minimum resistance of the air pipe is ensured; the air exhaust diffusion speed is improved by improving the air speed at the outlet of the air exhaust pipe; the variable cross-section air exhaust vertical pipe is arranged on the ground, and the air exhaust amount is 10000-30000 m³When the wind speed of the air pipe is 6-8 m/s, the diffusion height of the air exhaust containing pollutants in the laboratory is increased by 28% -54%, the cost is only increased slightly, in addition, all shielding and blocking of the air exhaust pipe are eliminated, so that the diffusion speed and the diffusion height of the air exhaust containing pollutants are increased, the factory boundary concentration of pollutant emission is effectively reduced, and the environment improvement of a laboratory area is facilitated.

The technical solutions provided by the embodiments of the present invention are described in detail above, and the principles and embodiments of the present invention are explained herein by using specific examples, and the descriptions of the above embodiments are only applicable to help understand the principles of the embodiments of the present invention; meanwhile, a person skilled in the art can change the embodiments and the application ranges according to the embodiments of the present invention, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. A high-speed exhaust for laboratory mechanical ventilation, comprising: the air exhaust vertical pipe (1) is a gradual change pipe with a continuous variable cross section or a pipeline with a sectional variable cross section structure so as to change the cross section of the air exhaust vertical pipe (1), one end of the air exhaust vertical pipe (1) is arranged on the ground, the other end of the air exhaust vertical pipe penetrates through a roof surface layer and extends out of the room, and the air exhaust speed of the air exhaust vertical pipe is larger than 12 m/s.

2. A high velocity discharge apparatus for laboratory mechanical ventilation according to claim 1, characterized in that: one side of the indoor part of the exhaust vertical pipe (1) is provided with a three-way pipe (2), and a port of a bypass of the three-way pipe (2) is connected with the exhaust unit and receives air to be exhausted from the exhaust unit.

3. A high velocity discharge apparatus for laboratory mechanical ventilation according to claim 2, characterized in that: and a steel wire mesh (3) is arranged in the three-way pipe (2).

4. A high velocity discharge apparatus for laboratory mechanical ventilation according to claim 1, characterized in that: the bottom of the air exhaust vertical pipe (1) is provided with a water and snow collecting bin (4).

5. A high-speed discharge device for laboratory mechanical ventilation according to claim 4, characterized in that: a water seal and a drainage device (5) are arranged in the water and snow collecting bin.

6. A high velocity discharge apparatus for laboratory mechanical ventilation according to claim 1, characterized in that: the lower end of the air exhaust vertical pipe (1) is provided with an arc-shaped sealed air exhaust vertical pipe cleaning opening (6).

7. A high velocity discharge apparatus for laboratory mechanical ventilation according to claim 1, characterized in that: one end of the air exhaust vertical pipe (1) which is arranged on the ground is arranged on the air exhaust vertical pipe concrete foundation (7).

8. A high velocity discharge apparatus for laboratory mechanical ventilation according to claim 1, characterized in that: the outer side of the part of the vertical air exhaust pipe (1) extending out of the room is coated with an insulating layer (8).

9. A high velocity discharge apparatus for laboratory mechanical ventilation according to claim 8, wherein: and a galvanized steel sheet is adopted as a protective layer (9) on the outer side of the heat-insulating layer (8).

10. A high velocity discharge apparatus for laboratory mechanical ventilation according to claim 1, characterized in that: the conical rain cover (10) is arranged at the position where the air exhaust vertical pipe (1) is connected with the roof surface layer.