JP2008049306A - Apparatus for mixing gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that the size of a system becomes larger or the output of the system is decreased since a main conduit of a long section is required or several devices are arranged in the main conduit to cause a pressure loss in a fluid when two fluids are mixed almost uniformly with each other. <P>SOLUTION: An auxiliary conduit is arranged through which an additional gas is made to pass and an outlet of the auxiliary conduit is arranged to be opened to the vicinity of the center of the main conduit through which a main gas is made to pass. A plate for dispersing the additional gas in the radial direction or a frustum-like structure, the cross-sectional area of which is made larger as the cross section near the auxiliary conduit is parted from the auxiliary conduit, is arranged in the vicinity of the center of the main conduit just after the outlet of the auxiliary conduit. A whirling member having a plurality of stator blades or rotor blades for forming a whirling flow in a current of the main gas is arranged for promoting the mixing of the additional gas with the main gas. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fluid processing apparatus for an industrial machine, and relates to a structure of a gas mixing apparatus that supplies an additive gas into a main conduit for guiding a main gas fluid and mixes the two kinds of gas fluids in the main conduit.

  Nitrogen oxides (hereinafter referred to as NOx) contained in exhaust gas discharged from diesel engines such as large trucks and buses are substances that cause photochemical smog. With the strengthening of NOx emission regulations for vehicles that emit NOx, it has been proposed to install a denitration device in the exhaust gas pipe. As a removal (denitration) method, it has been studied to use non-toxic urea as a reducing agent so that NOx can be reduced with high efficiency.

  For example, urea water is used as a reducing agent, and a NOx reduction catalyst disposed in the exhaust pipe is provided in order to obtain a high NOx reduction rate from a relatively low temperature range, and upstream of the NOx reduction catalyst In the exhaust gas purification apparatus configured to add urea water as a reducing agent, a urea decomposition catalyst is provided between the urea water addition position in the longitudinal direction of the exhaust pipe and the NOx reduction catalyst, and the urea water is decomposed in the preceding stage. The catalyst is decomposed into ammonia and carbon dioxide, and the NOx is efficiently reduced by the highly reactive ammonia obtained thereby, so that the NOx is released from a relatively low temperature range compared with the case where urea water is reacted with NOx as it is. There is an exhaust purification device that can reduce and purify the exhaust gas (for example, see Patent Document 1).

  Moreover, there is a urea SCR system as an exhaust purification device that does not include the urea decomposition catalyst of the exhaust purification device (for example, see Non-Patent Document 1).

Special table 2003-505638 Kodaka Matsuo “Challenge to Ultra Low Emission Diesel Engine” Journal of the Japan Society of Mechanical Engineers, 2002.10 Vol. 105 No. 1007, p. 23

  In the prior art, when two kinds of fluids are mixed almost uniformly, a long section main conduit is required, or several devices are arranged in the main conduit to give pressure loss to the fluid, thereby mixing the fluid. A way to promote it has been taken.

  However, for example, an exhaust gas treatment device mounted on a truck, a bus or the like is not preferable because a large-sized main conduit is required, resulting in an increase in the size of the system. In addition, if the pressure loss of this system is large, the engine output will be reduced. It is not preferable to be mounted in any case the car for this purpose. In addition, similar problems are expected to occur in other industrial machines.

  An object of this invention is to provide the gas mixing apparatus which can mix two types of gas efficiently in a short area. An object of the present invention is to provide a gas mixing apparatus that can mix two kinds of gas fluids substantially uniformly and can suppress pressure loss with a compact configuration.

  In order to achieve the above object, the present invention is configured as follows.

  An outlet opening of the auxiliary conduit having an opening for discharging the additive gas in a direction along the flow of the main gas is disposed near the center of the main conduit through which the main gas passes.

  Preferably, an annular plate for radially dispersing the additive gas at a position facing the auxiliary conduit outlet, or a cross-sectional area when crossed by a plane perpendicular to the main gas flow is separated from the outlet of the auxiliary conduit. A frustum structure that increases in size is disposed.

  Further, in order to promote the mixing of the additive gas and the main gas, a swirling member having a plurality of stationary blades or moving blades for forming a swirling flow is provided.

  The gas referred to in this specification includes not only a gas but also a two-phase flow in which fine droplets are mixed.

According to the present invention,
Regardless of the flow rate of two different fluids, it is possible to provide a gas mixing apparatus that can efficiently mix uniformly in a short section.

  Embodiments of the present invention will be described below with reference to the drawings shown in FIGS.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a partial cross-sectional view of a gas mixing apparatus showing a first embodiment according to the present invention.

  The auxiliary conduit 2 through which the additive gas passes extends from the side surface of the main conduit 1 through which the main gas passes to the vicinity of the inner center, and the tip opening (passage outlet) is downstream of the axial flow of the main gas flowing through the main conduit 1. It is bent and arranged in an L shape toward the head.

  In addition, a frustum structure 5 whose cross-sectional area increases as the cross section near the auxiliary conduit 2 moves away from the auxiliary conduit 2 is disposed near the center of the main conduit immediately after the outlet 3 of the auxiliary conduit 2. The frustum structure 5 is provided with a plurality of guide plates 7 having a predetermined height for uniformly distributing the gas flow radially from the center of the main conduit 1 on the frustum surface.

A swirling member 6 having a plurality of stationary blades 6A for forming a swirling flow in the flow is disposed downstream of the frustum structure 5. Here, twelve stationary blades 6A are arranged, and the number is appropriately selected depending on the size of the conduit, the flow rate of the gas flow, and the like. The stationary blades 6A are inclined with respect to the streamlines of the gas flow in the main main conduit 1. In the embodiment, twelve blades 6A are arranged at equal intervals on the outer periphery of the frustum structure 5.

  Next, the effect of the auxiliary conduit 2 will be described. The auxiliary conduit 2 for guiding the additive gas to the main conduit 1 opens toward the downstream side of the main gas near the center of the main conduit 1. As a result, the added gas is discharged near the center of the main gas passing through the main conduit 1 and the main conduit 1. As a result, the additive gas is stably supplied near the center of the main conduit 1 regardless of the flow rate of the additive gas or the main gas.

  Next, the effect of the frustum structure 5 will be described. By supplying a frustum structure 5 whose cross-sectional area increases as the distance from the auxiliary conduit 2 increases in the vicinity of the center of the main conduit 1 immediately after the outlet 3 of the auxiliary conduit 2, supply to the center of the main conduit 1 The added gas is distributed almost uniformly 360 ° in the radial direction of the main conduit 1. Further, the guide plate 7 disposed on the frustum surface promotes the effect of uniformly dispersing the additive gas. The dispersed additive gas is mixed with the main gas passing through the main conduit 1. Further, a vortex is generated in the space immediately after the frustum structure 5 due to its resistance, and gas mixing is further promoted.

  Next, the effect of the turning member 6 will be described. A swirling member 6 having a plurality of stationary blades 6A is arranged in the main conduit 1 immediately after the outlet of the auxiliary conduit 2, thereby forming a swirling flow in the gas flow, and the additive gas and the main gas are stirred to promote mixing. Is done. For efficient mixing, the larger the number of stationary blades 6A, the better. Similarly, for efficient mixing, the attachment angle (tilt angle) of the stationary blade 6A is preferably 45 ° or more with respect to the axial flow direction (streamline direction of the gas flow) of the main conduit 1. The stationary blade 6A can also be configured by a moving blade whose inclination can be adjusted.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the frustum structure configured in the first embodiment is changed to a disk-shaped plate 4 to simplify the system components. In this case, the additive gas supplied from the outlet 3 of the auxiliary conduit 2 to the central portion of the main conduit 1 collides with the plate 4 almost vertically. The impinging additive gas is distributed almost uniformly by 360 ° along the surface layer of the plate 4 in the radial direction of the main conduit 1. Even in such a simple disk shape, the same effect as in the first embodiment can be obtained. Similar to the first embodiment, the swirling member 6 provided with the stationary blade 6A is disposed on the rear side, the swirling force is applied to the gas flow, and the additive gas and the main gas are stirred to promote mixing.

  Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, the disk-like plate 4 configured in the second embodiment is integrated with the swivel member 6 to further simplify system components. As a result, the system can be made compact and the assembly can be improved. The performance of the third embodiment is almost the same as that of the second embodiment.

  Specifically, a cylindrical body 4A having a disc-shaped end face is provided at a position facing the outlet 3 of the auxiliary conduit 2, and the stationary blade 6A is fixed around the cylindrical body.

  Next, a fourth embodiment of the present invention will be described with reference to FIGS. In the fourth embodiment, a small frustum structure 8 is disposed at the outlet 3 of the auxiliary conduit 2. Thereby, the frustum structure of Example 1 can be omitted, and the system can be made compact. The performance of Example 4 is almost the same as that of Example 2. In addition, a plurality of additive gas outlets 8A are opened around the frustum structure 8 toward the radially outer side.

  In the third and fourth embodiments, the turning member 6 can be rotated in the main conduit 1 by rotatably supporting the cylindrical body 4A on the main conduit 1 or the auxiliary conduit 2. In this case, gas mixing is further promoted.

  According to each of the embodiments described above, in the gas mixing device that uniformly mixes two different types of fluids, the mixing of the additive gas and the main gas can be effectively achieved in a space-saving manner.

The modes of the examples are summarized as follows.
(1) In the gas mixing device according to claim 1,
A gas mixing device characterized in that the additive gas is discharged near the center of the main conduit through which the main gas passes, and the auxiliary conduit outlet opens near the center of the main conduit.
(2) In the gas mixing device,
A plate for dispersing the additive gas in the radial direction from the vicinity of the center in the main conduit downstream from the outlet of the auxiliary conduit or a frustum structure having a cross-sectional area that increases in cross section as the distance from the conduit increases. A gas mixing device characterized by being arranged.
(3) In the gas mixing device,
A swirling member having a plurality of stationary blades or moving blades for forming a swirling flow in the fluid passing through the main conduit is disposed in the main conduit immediately after the auxiliary conduit outlet through which the additive gas passes. Gas mixing device.

  According to the gas mixing apparatus of the embodiment, the following effects can be obtained.

  The additive gas is effectively discharged near the center of the main conduit through a conduit that opens near the center of the main conduit.

  Further, by arranging a plate or a frustum structure whose cross-sectional area increases as the distance from the conduit increases near the center in the main conduit downstream of the auxiliary conduit outlet, the additive gas is disposed near the center in the main conduit. To the radial direction.

  Furthermore, the main gas immediately after the outlet of the auxiliary conduit is provided with a swirling member having a plurality of stationary blades or moving blades for forming a swirling flow in the fluid passing through the main conduit. To promote efficient mixing.

  By implementing the present invention in a urea catalyst device that denitrates NOx discharged from a diesel engine, exhaust gas and ammonia can be mixed efficiently while being a compact device, so NOx can be removed at a high denitration rate. Is possible.

  In this case, in each of the above-described embodiments, a device for vaporizing urea into ammonia is attached upstream of the auxiliary conduit 2, the main gas is exhaust gas of the diesel engine, and the upstream end of the main conduit 1 is the diesel engine exhaust gas. Connected to the exhaust pipe, the downstream end is connected to a urea catalyst device for denitrating NOx.

  Therefore, it can utilize for various industries including the automobile industry which uses a diesel engine. In addition, even when used in industrial equipment similar to that, a sufficient effect can be expected in terms of compactness and high efficiency.

  By the above solution, it is possible to realize a gas mixing device that can efficiently and uniformly mix in a short section regardless of the flow rates of two different fluids. That is, the additive gas is discharged to the center of the main conduit through which the main gas passes, and further, the additive gas is moved radially from the vicinity of the center of the main conduit by a plate or a frustum structure near the center of the main conduit immediately after the outlet of the auxiliary conduit. To disperse. Further, the additive gas and the main gas are agitated by the swiveling member immediately after the plate or the frustum structure, and the mixing is efficiently promoted. This makes it possible to achieve efficient and uniform mixing in a short section regardless of the flow rates of the two different fluids.

  The present invention relates to a gas mixing apparatus that uniformly mixes two different types of gas fluids in a short section. It can be used for diesel engine cars and boilers.

It is a figure which shows the gas mixing apparatus of the 1st Example which concerns on this invention. It is a bird's-eye view and a partial sectional view of the gas mixing apparatus shown in FIG. 1 according to the present invention. FIG. 6 is a diagram showing an embodiment in which the frustum structure 5 of FIG. 1 is replaced with a dispersion plate 4 in Embodiment 2 according to the present invention. It is a bird's-eye view and a partial sectional view of the gas mixing apparatus shown in FIG. 3 according to the present invention. In Example 3 which concerns on this invention, it is a figure which shows the Example which integrated the board comprised in Example 2 with the turning member. It is a bird's-eye view and a partial sectional view of the gas mixing apparatus shown in FIG. 5 according to the present invention. In Example 4 which concerns on this invention, it is a figure which shows the Example which has arrange | positioned the small frustum structure to the exit of an auxiliary | assistant conduit | pipe. It is a bird's-eye view and a partial sectional view of the gas mixing apparatus shown in FIG. 7 according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Main conduit, 2 ... Auxiliary conduit, 3 ... Exit of auxiliary conduit, 4 ... Plate, 5, 8 ... Frustum structure, 6 ... Turning member, 7 ... Guide plate.

Claims (20)

A nozzle that is installed in a conduit through which the first fluid flows and supplies a second fluid in a direction along the flow of the first fluid;
A fluid dispersion mechanism is provided to face the outlet opening of the second fluid provided in the nozzle and guide the second fluid supplied from the nozzle toward the inner wall of the conduit. Gas mixing device. In claim 1,
Furthermore, the gas mixing apparatus characterized by having the mixing mechanism which mixes the 2nd fluid disperse | distributed by the said dispersion | distribution mechanism with the said 1st fluid around the downstream of the said dispersion | distribution mechanism. In what is described in claim 2,
The mixing mechanism includes a plurality of inclined blades extending radially between the dispersing mechanism and the inner wall of the conduit around the dispersing mechanism and having an inclined angle with respect to the flow of the first fluid. A gas mixing device characterized by being made. In the thing in any one of Claim 1 thru | or 3,
The gas mixing apparatus, wherein the dispersion mechanism includes a disk member. In the thing in any one of Claim 1 thru | or 3,
The gas mixing apparatus, wherein the dispersion mechanism includes a conical surface member having a vertex portion at a position facing the outlet opening of the second fluid provided in the nozzle. The thing of Claim 5 WHEREIN:
A gas mixing apparatus, comprising: a plurality of guide blades radially extending from an apex position facing the outlet opening of the nozzle and radially outward from the surface of the conical surface member. A conduit leading the first fluid,
A nozzle installed in the conduit and having an opening for supplying a second fluid in a direction along the flow of the first fluid;
A gas mixing device provided with a guide member provided at a position facing the opening and dispersing the second fluid in a radial direction. What is described in claim 7,
Furthermore, a gas mixing device provided with a mixing mechanism that is provided around the downstream side of the guide member and mixes the second fluid dispersed by the guide member with the first fluid. What is described in claim 8,
Gas mixing comprising a plurality of inclined blades, the mixing mechanism extending radially between the dispersing mechanism and the inner wall of the conduit around the dispersing mechanism and having an inclined angle with respect to the flow of the first fluid apparatus. The thing of Claim 7 WHEREIN:
The gas mixing apparatus, wherein the dispersion mechanism includes a conical surface member having an apex portion at a position facing an outlet opening of the second fluid provided in the nozzle. The thing of Claim 7 WHEREIN:
The gas mixing device, wherein the guide member includes a disk member arranged to face an opening for supplying the second fluid of the nozzle. The thing of Claim 10 WHEREIN:
The conical member has a plurality of guide blades extending radially outward from a vertex position facing an outlet opening of the nozzle. It is a gas mixing device that mixes two different types of gas fluids,
The outlet of the auxiliary conduit for guiding the additive gas opens near the center of the main conduit through which the main gas passes, and the additive gas is supplied from the opening in a direction along the flow of the main gas. ,
Furthermore, the gas mixing apparatus characterized by providing the dispersion | distribution mechanism which disperse | distributes addition gas to a radial direction in the position facing the exit of the said auxiliary | assistant conduit | pipe. The gas mixing device according to claim 13.
The gas mixing device according to claim 1, wherein the dispersion mechanism is a disc-like dispersion plate installed in a plane near the outlet of the auxiliary conduit and intersecting the main gas flow. The gas mixing device according to claim 13.
The gas mixing device is characterized in that the dispersion mechanism is constituted by a plurality of openings provided at the outlet of the auxiliary conduit to discharge the additive gas radially to the main conduit. The gas mixing device according to claim 13.
A frustum structure that is arranged to face the outlet of the auxiliary conduit through which the additive gas is discharged and has a cross-sectional area that increases as the distance from the outlet of the auxiliary conduit increases when the cross section is taken along a plane perpendicular to the flow of the main gas. A gas mixing apparatus comprising: The gas mixing device according to claim 13.
A gas mixing apparatus comprising a plurality of stationary blades arranged radially at an inclination angle with respect to the main gas flow on the downstream side of the outlet of the auxiliary conduit. The gas mixing device according to claim 16, wherein
A gas mixing apparatus, wherein a plurality of partition plates for guiding the additive gas radially outward are planted on a frustum surface of the frustum structure. The gas mixing device according to claim 15, wherein
A gas mixing apparatus characterized in that a conical structure having a convex portion on the upstream side with respect to the flow of the additive gas is disposed at the outlet of the auxiliary conduit. The gas mixing device according to claim 18,
The partition plate of the frustum structure is an inclined wing having an inclination angle with respect to the central axis of the frustum structure, and the frustum structure is configured to be rotatable around the central axis. Gas mixing device.

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