JP7187763B2 - flow diverter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flow dividing device, and more particularly, when snow grains are conveyed by a carrier air current in a pipeline and the flow is divided by connecting the outlet side of the pipeline to a plurality of flow dividing pipes, the structure is simple. and a diverting device capable of suppressing variations in concentration of snow particles for each diverted flow.

2. Description of the Related Art Conventionally, powder flow dividers have been used to divide powders that are transported by airflow.
Patent Literature 1 discloses an example thereof.
In this powder flow divider, a narrowed portion is provided at an inlet for introducing gas entrained with powder, and a truncated cone-shaped mixing chamber is provided downstream of the narrowed portion. A cylinder having a plurality of openings is inserted in the mixing chamber, and a plurality of branch pipes are provided in communication with the bottom plate of the mixing chamber.
According to such a configuration, when the powder is introduced into the mixing chamber through the curved pipe, the powder tends to segregate so as to be concentrated in the outward direction of the bend of the curved pipe. Since it enters the mixing chamber after being squeezed, mixing of the powder is promoted, and further mixing occurs when entering the mixing chamber from the squeezed part, and most of the powder enters the cylinder in the mixing chamber, and a plurality of openings are formed. The powder spouted out through the pipe is in a sufficiently mixed state in the mixing chamber, and even if there is segregation in the powder concentration in the cross-sectional direction of the pipe when it is introduced into the flow divider, it is possible to divide the flow with a uniform concentration. effect is played.

However, such a powder flow divider has the following technical problems due to the additional cylinder provided in the mixing chamber.
In other words, in some cases, clogging of the pipes may occur due to adhesion of powder in the mixing chamber.
More specifically, when the powder flows into the mixing chamber from the narrowed portion, the flow velocity of the powder decreases, so the powder flows into the cylinder, the inner peripheral surface of the mixing chamber, or the bottom plate having an opening connected to the branch pipe. may adhere to This is particularly noticeable when the powder is snow grains containing moisture. When the speed of the conveying air is low, the snow grains adhering to the bottom plate form mountains, which may block the opening of the cylinder. situation may occur.

In addition, Patent Document 2 discloses another flow separation device for granular materials.
This granular flow dividing device is
A branched flow of powder and granules arranged between a main pipe for pumping powder and granules by airflow in the pipe and a plurality of branch pipes each having an upstream end face arranged parallel to the downstream end face of the main pipe. a device,
The granular material flow dividing device comprises: a rotor having an upstream end face and a downstream end face parallel to the downstream end face of the main pipe and the upstream end face of each of the plurality of branch pipes; a rotation drive unit that rotates at a predetermined rotation speed about the axial direction,
The rotating body has therein a pumping flow path that axially penetrates the rotating body,
The pumping channel has an intake port on the upstream end face that is arranged in a non-contact manner so as to closely face an outflow opening provided on the downstream end face of the main pipe, and the plurality of the plurality of a discharge port arranged in a non-contact manner so as to face the inflow opening provided on the upstream end face of each branch pipe,
The discharge port is configured such that the inflow openings of the plurality of branch pipes are positioned on the passage locus of the discharge port caused by the rotation of the rotating body.

According to such a granular material flow dividing device, the granular material is divided into a plurality of branch pipes from the main pipe for pressure-feeding the granular material by the air flow through the pressure-feeding flow path of the rotating rotating body. is possible.
More specifically, the powder or granular material to be pumped flows out from the outflow opening of the main pipe together with the air flow, and is pumped into the pumping channel inside the rotating body rotated at a predetermined rotational speed about the axial direction of the rotating body by the rotation driving part. from the intake port, out of the discharge port, and diverted to each of the plurality of branch pipes from the inflow opening of each of the plurality of branch pipes disposed in close proximity to the discharge port.
In this case, the discharge port is provided so that the inflow opening of each of the plurality of branch pipes is positioned on the passage trajectory of the discharge port due to the rotation of the rotating body. By sequentially switching the inflow openings of each of the plurality of aligned branch pipes, when the powder or grain that is pressure-fed by the air flow is branched from the main pipe to the plurality of branch pipes, the divided flow rate of the powder or grain for each branch pipe It is possible to reduce the bias of

However, such a powder flow dividing device can reduce the deviation of the flow of powder for each branch pipe compared to the powder flow dividing device described in Patent Document 1. It is necessary to provide a rotating body using a power source between the pipe and the branch pipe, and to connect each of the main pipe and the branch pipe, which are non-rotating bodies, to the rotating body in a non-contact and sealed manner. It is complex, large-scale and expensive.

Japanese Utility Model Laid-Open No. 63-17129 JP 2014-215004

SUMMARY OF THE INVENTION In view of the above technical problems, an object of the present invention is to simplify the process of conveying snow grains by means of a conveying air current in a pipeline and dividing the flow by communicating the outlet side of the pipeline with a plurality of branch pipes. To provide a flow dividing device capable of suppressing variations in concentration of snow grains for each flow by means of its structure.

The inventors of the present application have made the present invention by paying attention to the characteristics of snow grains that are to be diverted and the snow grains being transported through the pipeline.
The flow dividing device of the present invention is
a straight pipeline for transporting snow grains by a transport airflow;
a narrowed portion provided at a predetermined position inside the straight pipe so as to narrow the flow channel area;
a partition that divides the outlet of the straight pipeline into a plurality of regions, and a rectifying grid provided on the upstream side of the constricted portion in the conveying direction,
The narrowed portion has a diameter-reduced portion whose diameter is reduced toward the downstream side of conveyance and an increased-diameter portion whose diameter is increased toward the downstream side of conveyance, and a boundary portion between the diameter-reduced portion and the diameter-increased portion is , constitutes the minimum channel cross-section, and
A tangent line at the boundary is provided along the direction of the carrier airflow,
The constricted portion is provided at a predetermined position inside the straight pipeline so that the snow grains are guided to the center of the pipe before reaching the outflow port of the straight pipeline.

Further, the partition extends radially from the center of the outlet toward the periphery,
Both the diameter-reduced portion and the diameter-enlarged portion preferably form an annular shape rotationally symmetrical with respect to the central axis of the straight pipeline.
Furthermore, the area of the minimum channel cross-section is preferably set according to the velocity of the carrier airflow and the pressure loss of the channel.

Furthermore, the throttle angle of the diameter-reduced portion is preferably set according to the velocity of the conveying airflow, the distance between the top of the throttle and the center of the straight pipe, and the diffusion distance.
In addition, the rectifying grid has a cross section that intersects with the extending direction of the straight pipeline, and is entirely mesh-like,
In the rectifying grid, each grid having a mesh-like cross section on the entire surface preferably extends in a flow channel shape over a predetermined length in the extending direction of the straight pipeline.

Also, the snow grains may be artificial snow made of ice grains.
Furthermore, a plurality of constricted portions having the same shape and/or different shapes may be provided in series along the extending direction of the straight pipeline.
Furthermore, in the outflow port of the straight pipeline, each sectioned region may be connected to a branch pipe for communication.
In addition, a plurality of rectifying grids may be provided, and adjacent rectifying grids may be spaced apart by a predetermined interval in the extending direction of the straight pipeline.

The granular flow dividing device of the present invention will be described below in detail, taking as an example a case where artificial snow is divided by the granular flow dividing device of the present invention and used for a snow environment test.
First, the snow environment test system will be described. As shown in FIG. 1, the snow environment test system 10 uses artificial snow made of ice particles and puts the artificial snow on an air current from behind to simulate a snowstorm. , and is configured to blow toward a vehicle V, which is a test specimen, and has a blizzard supply system 12 and an airflow supply system 14 for that purpose.
In particular, when using a required amount of snowstorm having a predetermined snow quality in which ice grain size and moisture content are the main influencing factors, and blowing continuously toward the vehicle V, the entire height of the vehicle V and In order to spread across the entire width direction and, in some cases, achieve the desired snowstorm concentration distribution in the height direction of the vehicle V, a group of ice particles used as artificial snow is placed under prescribed temperature and humidity control. It is required to manufacture and promptly supply just before the test.

More specifically, the snow environment test system 10 includes a wind tunnel 16 in which a vehicle V to be tested is placed, a cold room 18 placed above the wind tunnel 16, and an ice making room placed above the cold room 18. (not shown), an ice-making machine 22 is disposed in the ice-making chamber, and an ice temperature stabilization conveyor 24, an ice crusher 26, a blower 28, a cooler 30, and a wet snow in the low-temperature chamber 18. A device 34 is arranged, and in the wind tunnel 16, an artificial snow flow dividing device 100, an artificial snow blowing nozzle 36, and a snowstorm collecting device 38 are arranged. is crushed in a low-temperature room 18 to form ice particles to produce artificial snow, the artificial snow is pumped toward the wind tunnel 16, and in the wind tunnel 16, the wet snow artificial snow is diverted to a low temperature It is configured to be placed on the air current and turned into a snowstorm and blown toward the vehicle V.

The snow blowing supply system 12 is provided with three systems, and each system includes a snow supply pipe 40 (more precisely, the snow supply pipe 40 is connected to the snow supply pipe 40 via a flow dividing device 100). Each of a plurality of branch pipes 210 connected to the blowout nozzle 36), and an air duct 44 connecting the suction port 42 in the wind tunnel 16 and the ice crusher 26 are provided. The wet snow device 34 and the artificial snow diverter 100 are connected between the blowing nozzle 36, while the air duct 44 connects the blower 28 and the ice crusher 26 between the suction port 42 in the wind tunnel 16 and the ice crusher 26. device 30 is connected.

The ice-making machine 22 is a so-called reamer-type ice-making machine 22 that produces crack-shaped ice pieces, and a plurality of ice-making machines 22 that produce crack-shaped ice pieces according to the total required amount of artificial snow used in the snow environment test. An arbitrary number of machines are selected from among them, and ice is made by the selected ice making machine 22 according to changes in the required amount of artificial snow to be used in the environmental test. In each of the selected ice making machines 22, the evaporation temperature and/or the water temperature and/or the rotation speed of the reamer are adjusted according to the difference between the required amount of artificial snow and the coarsely adjusted ice-making amount. and a control device that finely adjusts the amount of ice to be made.

The ice crusher 26 mainly consists of a rotary feeder (not shown) located at the top and a pair of crushing drums (not shown) located at the bottom, fed by the ice temperature stabilization conveyor 24. Ice pieces are quantified by a rotary feeder, supplied to a pair of crushing drums, crushed by the pair of crushing drums, and supplied to a snow supply pipe 40 as ice particles of a predetermined grain size. The ice temperature stabilization conveyor 24 forcibly drafts the ice particles conveyed on the conveyor with an air flow to increase the amount of heat exchange between the ice particles and the air, thereby reducing the temperature of the ice particles to the ambient air of the forced draft. Try to keep the temperature close.

The wet snow device 34 has a hot air supply pipe that communicates with a snow supply pipe 40. The hot air supply pipe extends at its downstream end over a predetermined length in the direction in which the snow supply pipe 40 extends. The snow supply pipe 40 has a hot air inlet forming an annular space covering the entire outer peripheral surface of the snow supply pipe 40. A plurality of hot air inlet openings are evenly provided on the outer peripheral surface of the snow supply pipe 40 covered by the annular space. At the downstream side of the hot air inlet 40, an aging space is provided in the snow supply pipe 40, i.e. heat exchange between the hot air and the air flow and the ice grains pumped by the air flow under a uniform atmospheric temperature inside the pipe. is formed so as to gradually advance the region.
The moisture content of the wet snow is adjusted through adjustment of the ambient temperature within the snow supply pipe 40 by adjusting the temperature and/or flow rate of the hot air and the temperature and/or flow rate of the transport air stream. The moisture content of wet snow is, for example, 1% to 30% in a snow environment test using a vehicle as a test piece.
In this case, while the wet snow ice particles P are pumped through the snow supply pipe 40 by the air flow, the flow rate of the ice particles P that adhere to the inner surface of the snow supply pipe 40 and are pumped is reduced with time. The predetermined speed of the conveying airflow is preferably 3 meters per second or more, in order to reliably prevent the failure of the pumping of the ice particles P due to the blockage of the snow supply pipe 40 . The higher the moisture content of the wet snow, the more likely it is to adhere to the inner surface of the snow supply pipe 40. Therefore, it is necessary to increase the speed of the conveying airflow accordingly. As will be described later, each of the plurality of flow dividing pipes 210 connected to the snow supply pipe 40 via the flow dividing device 100 has an inner diameter smaller than the inner diameter of the snow supply pipe 40. apply.

Regarding the airflow supply system 14, the wind tunnel 16 is formed in a part of the circulation space, and is configured to blow a snowstorm over the height of the vehicle V in one direction from the front to the rear of the vehicle V. Specifically, the blower 25 installed in the circulation space generates an airflow with a predetermined wind speed in one direction from the front to the rear of the vehicle V. After passing through the vehicle V, the airflow is cooled to a predetermined temperature by the cooler 27. After being cooled, it is returned to the blower 25 to generate an air flow again, and this is repeated.
Regarding the blowing nozzles 36, a plurality of snow blowing nozzles 36 forming a set are arranged at predetermined intervals in front of the vehicle V across the width direction of the vehicle V at predetermined intervals in the width direction of each system. be. The blowing nozzles 36 of each system are arranged at predetermined intervals in the height direction over the vehicle height of the vehicle V, and the density of the blowing snow to be supplied can be adjusted for each blowing nozzle 36 of each system. ing. A snow collecting device 38 is arranged at a predetermined distance behind the vehicle V, and the blowing snow that has passed through the snow collecting device 38 passes through a suction port 42 in the wind tunnel 16 to a blower arranged in the low-temperature chamber 18 . 28, cooled by the cooler 30, returned to the ice crusher 26, made by the ice machine 22, fed to the ice crusher 26 by the ice temperature stabilization conveyor 24, mixed with ice grains to be crushed, and supplied again with snow. It is adapted for use in blowing a snowstorm out of blow nozzle 36 via tube 40 and diverter tube 210 .

A diffusion plate 74 is provided in front of each of the blowout nozzles 36, and snow blown out from the blowout nozzles 36 toward the vehicle V on the low-temperature airflow from the blower 25 hits the diffusion plate 74 and spreads outward in all directions. The snow blowing nozzles 36 of the three systems cooperate with each other to distribute the snow blowing in the front part of the vehicle V in the height direction of the vehicle V. As shown in FIG.
In this regard, since the wind tunnel 16 is not a so-called aerodynamic wind tunnel 16 but a simple wind tunnel 16, the distance between the blowout nozzle 36 and the front of the vehicle V is about 1 to 3 meters. The snow blowing from the blowing nozzle 36 spreads over the entire height at the front of the vehicle V for a short distance.

Next, the flow dividing device 100 will be described. As shown in FIG. a partition 150 that divides the outflow port 130 of the straight pipeline 110 into a plurality of regions 140;

The straight pipeline 110 has an inlet 105 that communicates with the snow supply pipe 40 and an outlet 130 that is connected to a plurality of branch pipes 210 .
As shown in FIG. 2, the regulating grid 160 is provided on the upstream side of the constricted portion 120 in the conveying direction, and is made of, for example, a hard vinyl chloride film, and forms a swirling flow F from the inlet 167 of the straight pipeline 110. The flow of snow grains flowing in through the opening is rectified by the rectifying grid 160 and reaches the constricted portion 120 .
A plurality of rectifying grids 160 (two, 160A and 160B in FIG. 2) are provided, and adjacent rectifying grids 160 are separated by a predetermined interval d in the extending direction of the straight pipeline 110 . The predetermined interval d may be appropriately set according to the conveying air velocity, the snow quality of the snow grains, the snow grain size, and the like.
In each of the rectifying grids 160, a cross section intersecting the extending direction of the straight pipeline 110 is formed in a mesh shape on the entire surface, and each grid 165 with a mesh-shaped cross section on the entire surface extends over a predetermined length in the extending direction of the straight pipeline 110. It extends like a channel.
Conditions such as the length of the regulating grid 160 in the extending direction of the straight conduit 110 and the mesh roughness of the grid 165 can be appropriately changed depending on the carrier air velocity, the snow quality of the snow grains, the snow grain size, and the like. The flow path in the regulating grid 160 is formed horizontally along the longitudinal direction of the straight pipeline 110. In other words, the cross section orthogonal to the extending direction of the straight pipeline 110 is entirely mesh-like. ing.
In addition, the rectifying grid 160 is formed of a grid-like mesh as shown in the figure, so that each grid 165 is configured by a channel having a rectangular cross section. or a honeycomb block. The flow passage formed by each lattice 165 may have a flow passage area inclined (enlarged or reduced) in the flow direction of the snow grain flow, or may have a mesh roughness ( channel side lengths) may be different.
As a modification, the regulating grid 160 may be an assembly of pipes having a predetermined blowout cross-sectional area, and the cross-sectional shape of each pipe may be circular, rectangular, polygonal, or the like, but a symmetrical shape is preferable.

The narrowed portion 120 has a diameter-reduced portion 180 whose diameter is reduced toward the downstream side of conveyance and an increased-diameter portion 190 whose diameter is increased toward the downstream side of conveyance. A portion 200 constitutes the minimum channel cross-section A.
Both the diameter-reduced portion 180 and the diameter-enlarged portion 190 have a circular shape that is rotationally symmetrical with respect to the central axis of the straight pipeline 110 . By forming a diffusion region whose cross section is concentric with the cross section of the flow path of the straight pipe 110 when diffusing toward, the flow is evenly divided at the outlet 130 of the straight pipe 110 .
In this regard, it is preferable to adjust the position of the narrowed portion 120 in the direction of airflow transport of the straight pipeline 110 from the viewpoint of guiding the snow particles that cannot be completely diffused to the center of the straight pipeline 110 .
The upper surfaces of the diameter-reduced portion 180 and the diameter-enlarged portion 190 are each planar, and the diameter-reduced portion 180 is gradually inclined upward from the inner peripheral surface 220 of the straight pipeline 110 toward the boundary portion 200 at an inclination angle Θ. As a result, the channel cross section perpendicular to the straight pipeline 110 gradually narrows, while the enlarged diameter portion 190 gradually slopes downward from the boundary portion 200 toward the inner surface of the straight pipeline 110, As a result, the cross section of the flow path perpendicular to the straight pipeline 110 gradually widens and matches the flow cross section of the straight pipeline 110 .

The constricted portion 120 may be made of a material different from that of the straight pipeline 110, for example, if the straight pipeline 110 is made of metal, it may be made of resin, for example.
In addition, the upper surfaces of the diameter-reduced portion 180 and the diameter-enlarged portion 190 each have a curved surface shape, and the tangent line at the boundary portion 200 of the straight pipeline 110 along the direction of airflow is aligned with the direction of the airflow. It may be provided.

The area of the minimum channel cross section A is set according to the velocity of the carrier airflow F and the channel pressure loss. The flow path pressure loss varies, for example, depending on the straight pipeline length L1 from the constricted portion 120 to the outflow port 130 .
Alternatively, the constricted portion angle Θ of the reduced diameter portion 180 is set according to the velocity of the carrier airflow F, the distance between the constricted portion vertex and the center of the straight pipe, and the diffusion distance.
Regarding this point, the straight pipeline length L1 tends to be shorter as the throttle angle Θ is larger, while the straight pipeline length L1 tends to need to be longer as the throttle angle Θ is smaller. .
In this case, the conveying speed of the snow grains S, that is, the speed of the conveying airflow F, is determined by the amount of artificial snow demanded per hour in the environmental test and/or the type of the snow grains S. , the throttle angle Θ or the straight pipe length L1 are affected.
More specifically, for example, when the snow grains S have a high moisture content of close to 30%, from the viewpoint of preventing adhesion to the inner peripheral surface 220 of the straight pipeline 110, the velocity of the carrier airflow F is high. is preferable, because it shortens the time for the snow particles S to pass through the straight pipeline 110 on the downstream side of the constricted portion 120, that is, the time for the snow particles S to spread. From the viewpoint of securing the area, it is preferable to increase the straight pipeline length L1.
In this case, if the throttle angle Θ is made too large, the conveying speed vector of the snow grains S changes abruptly, which increases the possibility that the snow particles S will adhere to the throttle. It is preferable to secure the straight pipeline length L1 without increasing the angle Θ.

As a modification, the narrowed portion 120 may be detachable from the straight pipeline 110, and the position of the narrowed portion 120 on the straight pipeline 110 may be adjusted according to the type of snow grains S, the transport speed, and the like. .
In this case, a plurality of narrowed portions 120 having different narrowed portion angles Θ and minimum passage areas are provided, and an appropriate narrowed portion 120 is selected from the plurality of narrowed portions 120 according to the type of the snow grain S, the transport speed, and the like. In that case, the position of the throttle portion 120 on the straight pipeline 110 may be changed. Furthermore, a plurality of narrowed portions 120 having the same shape and/or different shapes may be provided in series along the extending direction of the straight pipeline 110 . Differently shaped constrictions 120 may include, for example, different constriction angles Θ and/or different minimum flow areas, and may be appropriately spaced along the direction in which the straight conduit 110 extends.

The partition 150 has an integral structure extending radially from the central portion C of the outflow port 130 toward the peripheral edge 170 , and each radially extending tip is fixed to the inner peripheral surface 220 of the straight pipeline 110 .
More specifically, three partitions 150 are arranged at equal angular intervals (120°) in the circumferential direction of the outflow opening 130, and each of the partitions 150 is a thin plate provided so that the surface direction is along the airflow conveying direction. The thickness is set to the extent possible so as not to impede the flow channel area at the outflow opening 130 . As a result, the snow grains transported by the transporting airflow do not collide with the partition 150, and the snow grains themselves are not broken or the transport direction is deflected.
With such a partition 150, it is possible to suppress variations in the density of the snow grains S for each branch pipe 210. FIG.
The number of partitions 150 may be appropriately determined according to how many snow grains S are to be diverted.

At the outlet 130 of the straight conduit 110, each sectioned region 140 is communicatively connected to the branch pipe 210, whereby the snow grains S are dispersed in each branch pipe 210 in a state where the variation in density is reduced. It is designed to be split. For example, the flow dividing pipe 210 may be made of a flexible material, and by inserting the tip of the corresponding flow dividing pipe 210 into each of the fan-shaped regions 140 , the flow division pipe 210 may be connected to the straight pipe 110 .
For example, in each system, a plurality of outlets 130 of the straight pipeline 110 connected to the snow supply pipe 40 are spaced apart in the width direction of the vehicle from the outflow opening 130 so as to cover the entire width of the vehicle. may be branched to each of the branch pipes 210.

According to the flow dividing device 100 of the present invention, the artificial snow can be divided into a plurality of flow dividing pipes 210 via the flow dividing device 100 from the snow supply pipe 40 that pumps the artificial snow by airflow.
More specifically, first, the ice pieces made by the ice making machine 22 are crushed by the ice crusher 26 to become ice particles of a predetermined particle size, which are pumped by the airflow through the snow supply pipe 40 and fed by the wet snow device 34 to a predetermined size. Wet snow having a moisture content is further pumped by the snow supply pipe 40 and the branch pipe 210 toward the vehicle V, which is the test object, by air flow.

The wet snow to be pumped flows out from the outflow opening of the snow supply pipe 40 together with the air flow, and flows into the straight pipe 110 from the inlet 105. A cross section that intersects the extending direction of the straight pipeline passes through each grid 165 of the rectifying grid 160 formed in a mesh shape on the entire surface, and reaches the constricted portion 120 in a rectified state (G in FIG. 2). After passing through the constricted portion 120, the flow of particles diffuses toward the inner peripheral surface of the pipe due to constricted expansion. can be guided to the center of the pipe, and the flow of snow grains at the outlet 130 of the straight pipe 110 is diverted from the inflow opening 130 to each of the plurality of branch pipes 210 in a state in which drift is eliminated.
More specifically, in each of the three systems, the snow supply pipe 40 is divided into a plurality of branch pipes 210 arranged at predetermined intervals in the width direction of the vehicle so as to cover the entire width of the vehicle. be.

Next, in each system, the distributed wet snow is blown out from the blowout nozzle 36 at the tip of each branch pipe 210, and carried by the air blown from behind the blowout nozzle 36 and blown toward the vehicle as snowstorm.
In this case, the amount of snow blowing off from each blowing nozzle 36 has little variation, and the blowing from each blowing nozzle 36 is not intermittent, and can be made continuous within a range that does not hinder the execution of the test. Therefore, it is possible to conduct an appropriate snow environment test that closely simulates a natural blizzard.

According to the flow dividing device 100 having the above configuration, the straight pipeline 110 for transporting the snow grains S by the transport airflow F is provided with the straightening grid 160 on the upstream side of the constricted portion 120 in the transport direction. The cross section intersecting the extending direction of the snow grains passes through each grid 165 of the rectifying grid 160 formed in a mesh shape on the entire surface, and reaches the constricted portion 120 in a rectified state. , the throttle expansion diffuses toward the inner peripheral surface of the pipe, and by providing the throttle portion 120 at a predetermined position inside the straight pipe 110, it is possible to guide the snow particles S that cannot be completely diffused to the center of the pipe. By eliminating the uneven flow of the snow grain flow at the outlet 130 of the straight pipeline 110, when the outlet side of the straight pipeline 110 is communicated with a plurality of flow dividing pipes 210 to split the flow, the narrowed portion In addition, since the pipe line 110 is a straight pipe line 110 having a rectifying grid, it is possible to suppress variations in the concentration of the snow grains S for each branch flow with a simple structure in an elongated space that is not bulky.

Although the embodiments of the present invention have been described in detail above, those skilled in the art can make various modifications and changes without departing from the scope of the present invention.
For example, in the present embodiment, rectifier grid 160 is assumed to have a length in the direction in which straight pipeline 110 extends so that each grid 165 forms a flow path in the direction in which straight pipeline 110 extends. Although it has been described, the flow of snow grains is not limited to this. For example, as long as the flow of snow grains is rectified until it reaches the constricted portion 120, the rectifying grid 160 has a plate shape, and each grid 165 forms a through hole. Anything is fine.
For example, in the present embodiment, regarding the relationship between the straight pipeline length L1 on the downstream side of the constricted portion 120 and the inclination angle Θ of the diameter-reduced portion 180 of the constricted portion 120, the condition of the snow grains diverted to each of the flow dividing pipes is determined. However, it is not limited to this. For example, due to installation space restrictions, instead of shortening the straight pipeline length L1, the inclination angle Θ can be increased, or the throttle section 120 may be installed on the rectifying grid 160 side (upstream side).

For example, in the present embodiment, assuming that artificial snow is used as the granular material to be divided, the artificial snow is divided from the snow supply pipe 40 to the plurality of branch pipes 210 by pressure feeding, and the tip of each of the plurality of branch pipes 210 is divided. Although the case of simulating a snowstorm from the blow-out nozzle 36 provided in the nozzle 36 has been described, it is not limited to this, and any kind of powder or granules can be used as long as there is a need to uniformly divide the powder or granules of the pumping type. It is also effective for the body.
For example, in the present embodiment, artificial wet snow formed by crushing ice pieces has been described as the granular material to be diverted. The snow may be artificially crystallized snow that is generated using cool air with a predetermined humidity and a predetermined temperature, and it does not have to be wet snow.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall schematic diagram of an environmental test system in which a snow grain flow dividing device according to an embodiment of the present invention is installed; 1 is a partial perspective view of a snow grain diverting device according to an embodiment of the present invention; FIG.

A Minimum flow cross-sectional area
L Straight pipe length Θ Throttle angle
F swirling flow
S Snow grain V Vehicle X Rotation axis
C Center 10 Snow Environment Test System 12 Snowstorm Supply System 14 Airflow Supply System 16 Wind Tunnel 18 Cold Room 20 Ice Chamber 22 Ice Maker 24 Ice Temperature Stabilization Conveyor 26 Ice Crusher 28 Blower 30 Cooler 34 Wet Snow Device 36 Blowout Nozzle 38 Snowstorm Collection device 40 Snow supply pipe 42 Suction port 44 Air duct 46 Rotary feeder 48 Crushing drum 100 Flow dividing device 105 Inlet 110 Straight pipe line 120 Constricted portion 130 Outlet 140 Plural regions 150 Partition 160 Rectifying grid 165 Grating 170 Periphery 180 Contraction Diameter portion 190 Expanded diameter portion 200 Boundary portion 210 Divert pipe 220 Inner peripheral surface

Claims (9)

a straight pipeline for transporting snow grains by a transport airflow;
a narrowed portion provided at a predetermined position inside the straight pipe so as to narrow the flow channel area;
a partition that divides the outlet of the straight pipeline into a plurality of regions, and a rectifying grid provided on the upstream side of the constricted portion in the conveying direction,
The narrowed portion has a diameter-reduced portion whose diameter is reduced toward the downstream side of conveyance and an increased-diameter portion whose diameter is increased toward the downstream side of conveyance, and a boundary portion between the diameter-reduced portion and the diameter-increased portion is , constitutes the minimum channel cross-section, and
A tangent line at the boundary is provided along the direction of the carrier airflow,
The constricted portion is provided at a predetermined position inside the straight pipeline so that the snow particles are guided to the center of the pipe before reaching the outflow port of the straight pipeline.
A flow dividing device characterized by: The partition extends radially from the center of the outlet toward the periphery,
2. The flow dividing device according to claim 1, wherein both the diameter-reduced portion and the diameter-enlarged portion form an annular shape rotationally symmetrical with respect to the central axis of the straight pipeline. 3. The flow dividing device according to claim 1, wherein the area of the minimum cross section of the channel is set according to the velocity of the carrier airflow and the pressure loss of the channel. 3. The flow dividing device according to claim 1, wherein the constricted portion angle of the diameter-reduced portion is set according to the velocity of the conveying airflow, the distance between the constricted portion vertex and the center of the straight pipe, and the diffusion distance. The rectifying grid has a cross section that intersects with the extending direction of the straight pipeline, and is formed in a mesh shape on the entire surface,
5. The flow dividing device according to claim 3, wherein each grid of the rectifying grid has a mesh-like cross section on the entire surface and extends in a flow channel shape over a predetermined length in the extending direction of the straight pipeline. The flow dividing device according to claim 1, wherein the snow grains are artificial snow made of ice grains. The flow dividing device according to any one of claims 1 to 6, wherein a plurality of said constricted portions having the same shape and/or different shapes are provided in series along the extending direction of said straight pipeline. 2. The flow splitting device according to claim 1, wherein each sectioned region at the outlet of the straight conduit is connected to a flow splitting pipe for communication. 6. The flow dividing device according to claim 5, wherein a plurality of said rectifying grids are provided, and adjacent rectifying grids are spaced apart by a predetermined interval in the extending direction of said straight pipeline.

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