DE102006055655A1 - Dosing device for dosing liquid into gas stream i.e. flue gas stream of internal combustion engine of motor vehicle, has pressure production unit flowtechnically connected with radially aligned nozzles over inlet pipe - Google Patents

Abstract

The The invention relates to a device for injecting liquids into a gas stream, in particular in an exhaust gas stream of an internal combustion engine, with a tubular body (2), through which the gas flow passes. A pressure generator unit (3) serves to provide pressurized fluid, the above a distributor unit (4), liquid at least one circumferential on the tubular body (2) arranged supply line (5) distributed. The supply line (5) is with several at the periphery of the tubular body (2) trained to the tube body interior directed nozzles (6) fluidic connected.

Description

The The invention relates to a device for injecting liquids or gases into a gas stream, in particular in an exhaust gas stream of an internal combustion engine, with a tubular body, through the gas stream flows through it and a pressure generating unit for providing pressure applied liquid or acted upon gas.

to Treatment of exhaust gas streams or for heating catalysts, it is possible liquids or gases in the Inject exhaust stream, either to increase the exhaust gas temperature or pollutants over a reduce or reduce chemical reaction. In addition to the normal In particular, urea can be injected with fuel to reduce the nitrogen oxide concentration to reduce.

Out The prior art two-fluid nozzles are known in a nozzle lance are attached. This nozzle lance is inserted through a hole in the pipe wall into the pipe interior and there fixed. As a rule, this nozzle is aligned in the flow direction and as a hole or hollow cone nozzle educated. The injection the liquid thus takes place at a point within the gas stream under training a spray cone. The problem arises of an inhomogeneous distribution of the injected liquid within the gas stream. This leads to incomplete reactions and thus to an incomplete one Degradation of nitrogen oxides in a urea injection or to a incomplete Burning of the injected Fuel with adverse consequences for catalysts.

to improved homogenization are within the exhaust pipe baffles arranged in propeller-like configuration in front of or behind the injection point, to achieve a turbulence of the gas stream. Such guidance devices increase the flow resistance. About that addition, the problem is that a homogeneous distribution on a possible low flow path should take place because the exhaust pipe geometry can not be changed arbitrarily can.

task the present invention is to provide a device for a homogeneous injection of liquids or to allow gases into a gas stream. According to the invention this Task by a device having the features of claim 1 dissolved as well as a module with the features of claim 19. Advantageous Embodiments and developments of the invention are listed in the subclaims.

The inventive device for injecting of liquids or gases in a gas stream, in particular in an exhaust stream of a Internal combustion engine, with a tubular body through which the gas flow passes and a pressure generating unit for providing pressurized liquid or pressurized gas provides that the pressure generator unit with a plurality of radially aligned nozzles via at least one supply line aerodynamically connected is. By the radial injection of the liquid or gas, for example from the circumference of the pipe body inner wall and / or a radially outward injection device is on a short gas line a very homogeneous distribution of liquid or the gas in the gas stream. The following are the injected liquids or Gases referred to as media. These include mixtures of substances, to understand a variety of substances as well as individual substances. Basically exists the possibility, both liquids as well as gases simultaneously or sequentially introduced into the gas stream.

A Development of the invention provides that a distributor unit, the media to at least one, preferably circumferentially disposed on the tubular body Distributed supply line, with the supply line with several, on the perimeter of the tubular body trained, to the tube body interior directed nozzles aerodynamically connected is. By taking place radially from the outside in several places injection of the Media becomes a distribution and distribution on a very short distance the injected Media made within the gas stream.

A Development of the invention provides that the nozzles axially offset in the tubular body are arranged to flow in the direction to be able to inject the media in different places. The can Nozzles both radially as well as in the flow direction at an angle between 0 ° to 90 ° in the Spray pipe inside. Due to the correspondingly inclined nozzle axes is an adaptation of the spray behavior to the geometric and fluidic Conditions inside the pipe body possible. The nozzles can dependent on from the einzudüsenden Have different dimensions and circumferentially, thus azimuthally periodically or aperiodically offset, arranged on the tubular body be. In addition to conventional hole nozzles are hollow cone nozzles, Tongue nozzle, slot dies or flat jet nozzles provided a customized injection of the media into the gas stream enable.

The pressure generator unit is preferably fixed to the tubular body and is preferably designed as a piston pump, in particular a multi-piston pump, if a fluid is used as the medium is set. For gases other pressure generating devices are provided. This makes it possible to form the tubular body together with the pressure generator unit and optionally with the distribution unit to be defined on the tubular body as a module. The supply lines can be fastened on the outside of the tubular body or alternatively be formed within the tube body wall or between an inner tube and an outer tube via incorporated supply channels.

The Supply lines for the high pressure liquids run from the distributor unit separately to the respective nozzle or are about a common supply channel according to the so-called "common rail method" with the pressure generator unit coupled. The pressure must be at least so high that the Media injected into the gas stream can be.

to Anyone can train as a swirl chamber or for beam homogenization Nozzle one nozzle antechamber be upstream, the geometry of the nozzle prechamber preferred to the nozzle geometry is adjusted.

A Development of the invention provides that one or more guide devices on the pipe body inner wall arranged, in particular, are attached. The guiding devices usually protrude radially inwards and can meet in the center of the tubular body. In the guiding devices can Arranged nozzles be, with the pressure generator unit and possibly the distribution unit are connected, so that in addition to a purely radially directed from the outside injection also a spaced from the pipe inner wall injection radially inward, optionally also alternatively or additionally radially outward, can be done.

Of the Tubular body the pressure generator unit, the distribution unit and the supply lines can be designed as a module that in its dimensions adapted to that exhaust pipe which conducts the exhaust gas stream. By the separate production of the module can comply with the high-precision tolerances become. The module only has to be connected with suitable connection means be inserted between two exhaust pipe sections, so that also a retrofit can take place almost anywhere within the exhaust pipe. Likewise, the invention comprises a module from a pressure generator unit, a distribution unit and the supply lines, with a pipe body with radially inwardly directed nozzles is fitted, can be mounted. The pressure generator unit and the distribution unit can also form an integral component by the leads directly connect to the pressure chamber.

It is possible with the device described above, a Eindüsverfahren for media to realize in a gas stream, in which simultaneously or successively from different nozzles the media are fed into a gas stream. The can Be directed radially inward into a tubular body, so that the injection a uniform distribution causes the medium within the gas stream. The injection can from all nozzles directed radially inward, it is also intended that one or more webs are arranged within the gas flow, the radial outward directed nozzles exhibit. Thus, at the same time radially inward through the on Circumference arranged nozzles and radially outward introduced through the arranged on the webs or the nozzle, the medium in the gas stream be to improved, in particular homogeneous injection to reach.

following Be exemplary embodiments of Invention with reference to the attached Figures explained in more detail. Same Reference numerals relate to identical components. Show it:

1 A first embodiment of a injection module;

2 - 4 - Variants of 1 with different nozzle geometries;

5 - A module consisting of pressure generator unit, distribution unit and supply lines;

6 - An injection module with guide devices;

7 A variant of 6 ; such as

8th - An injection module with a Eindüssteg.

In the 1 is a perspective, schematic representation of a Eindüsvorrichtung 1 shown in modular form. The injection device 1 is from a tubular body 2 , in this case constructed with a round cross-section, in the wall of nozzles 6 are incorporated. The nozzles 6 are present as through holes in the pipe wall of the tubular body 2 formed, preferably eroded. On the outer circumference of the tubular body 2 are supply lines 5 arranged with a pressure distributor 4 and a pressure generator 3 for providing high pressure liquid. The supply lines 5 can either be designed separately and from the pressure manifold 4 the high pressure fluid to the respective nozzles 6 be guided or designed as a CommonRail, so that branches from a common supply channel to the respective nozzles 6 are formed.

At the end of the supply lines 5 is in each case a nozzle prechamber 7 designed, which are designed to adapt or influence the Eindüsverhaltens. Depending on the design of the nozzles 6 can use different geometries of the nozzle prechamber 7 available. Present are the nozzles 6 Alternatively, hollow cone nozzles, tongue nozzles, slot nozzles or flat jet nozzles in different orientations on the tubular body can be designed as simple hole nozzles 2 be educated.

The 2 shows a Eindüsvorrichtung 1 with axially aligned slot nozzles 6 and correspondingly formed nozzle prechambers 7 which also comes from multiple supply lines 5 can be fed.

3 shows azimuthally aligned slot nozzles 6 with correspondingly adapted nozzle prechambers 7 , In this case, the slot nozzles 6 annular on the inside of the tubular body 2 are arranged. In principle, the arrangement is also axially offset or aperiodic azimuthally possible.

In addition to a continuous training of the nozzles 6 As slot nozzles or hole nozzles, combinations of the nozzle shapes can be arranged periodically or aperiodically, as in US Pat 4 is indicated. Due to the correspondingly adapted nozzle prechambers 7 It can be seen that a combination of hole nozzles and azimuthally oriented slot nozzles on the tubular body 2 are arranged and formed.

5 shows a module consisting of pressure generator unit 3 , Distribution unit 4 and supply lines 5 which are formed corresponding to the outer periphery of the pipe body, not shown. This module can be pushed onto the tube body and fixed on it. It is important to ensure that the nozzle holes to cover with the ends of the leads 5 come, so that a precise injection of the pressure generator unit 3 supplied liquid can be made. The pressure generator unit 3 can be designed as a high-pressure pump, in particular as a multi-piston pump. Basically, the supply lines with increasing distance to the distribution unit 4 or the pressure generator unit 3 be narrowed in their cross-section in order to maintain sufficiently high pressures can.

In the 6 is an injection device 1 with radially inwardly directed guide devices 8th provided in the form of baffles. Through these baffles 8th For example, the flow conditions at the tube body inner wall or the injection behavior of the nozzle through the nozzles 6 introduced additive.

In the 7 is a variant of the arrangement of the guide devices 8th shown in the center of the tubular body 2 are merged. Basically, it is possible that through the baffles or baffles 8th Liquid through appropriately arranged nozzles in channels within the guide devices 8th is introduced, from where an injection into the gas stream radially outward, ie opposite to the Eindüsrichtung the nozzle 6 can be done in the tube body inner wall. In addition, an injection in or against the direction of flow through the guide 8th respectively.

A variant of the invention is in the 8th shown where the nozzles are within a ridge 8th , which is designed as a guide, are arranged. The nozzles 6 are inside the footbridge 8th arranged perpendicular to the flow direction and allow injection over the entire cross-section in the flow direction, so that a uniform and homogeneous distribution of the injected liquid can take place. The nozzle geometry or number of nozzles may be over the cross section of the tubular body 2 change in order to take into account the different flow conditions of the gas stream. The nozzles 6 can either be exclusively in the guide 8th which preferably has no fluid-dynamic tasks or both in the guide 8th as well as in the tubular body inner wall 2 be arranged to allow a homogeneous injection.

Basically, an integral design of the supply lines 5 inside the pipe body 2 possible, for example, by a two-part design of the tubular body 2 with an inner tube and outer tube and incorporated supply channels.

The injection device 1 has a small footprint and can be used at almost any point within an exhaust stream, for example in a motor vehicle. The pipe body 2 Can be cast with holes or anodized nozzles 6 be designed with high accuracy. As a result, a short gas run length is possible with a high uniform distribution of the additives within the exhaust gas flow. This is done over the majority of nozzles 6 achieved, radiate radially, be it radially inwardly over the tube body inner wall or radially outward via a guide 8th or in combination both radially inward and radially outward. In addition to the injection of liquid or liquids also gas or gases can be injected.

Claims (20)

Device for injecting liquids into a gas stream, in particular into an exhaust gas stream an internal combustion engine, having a tubular body through which the gas flow passes, and a pressure generating unit for providing pressurized fluid, characterized in that the pressure generating unit ( 3 ) with a plurality of radially aligned nozzles ( 6 ) via at least one supply line ( 5 ) is fluidically connected, Apparatus according to claim 1, characterized in that a distributor unit ( 4 ) the liquid from the pressure generator unit ( 3 ) to the at least one supply line ( 5 ) distributed with several at the circumference of the tubular body ( 2 ) formed, directed to the tube body interior nozzles ( 6 ) is fluidically connected. Apparatus according to claim 2, characterized in that the supply line ( 5 ) circumferentially on the tubular body ( 2 ) is arranged. Device according to one of the preceding claims, characterized in that the nozzles ( 6 ) are arranged offset axially in the flow direction. Device according to one of the preceding claims, characterized in that the nozzle axis at an angle of 0 ° to 90 ° to the radius of the tubular body ( 2 ) is aligned. Device according to one of the preceding claims, characterized characterized in that the nozzle axis at an angle to the flow direction of the Gas is inclined. Device according to one of the preceding claims, characterized in that the pressure generating unit ( 3 ) on the tubular body ( 2 ). Device according to one of the preceding claims, characterized in that the pressure generator unit ( 3 ) is designed as a piston pump, in particular a multi-piston pump. Device according to one of claims 2 to 8, characterized in that the distributor unit ( 4 ) on the tubular body ( 2 ). Device according to one of the preceding claims, characterized in that the supply line ( 5 ) on the outside of the tubular body ( 2 ) is attached. Device according to one of claims 1 to 9, characterized that the supply lines in the tube body wall or between a Inner tube and an outer tube are formed with incorporated supply channels. Device according to one of claims 2 to 11, characterized in that the supply lines ( 5 ) from the distribution unit ( 4 ) separately to the respective nozzle ( 6 ). Device according to one of claims 1 to 11, characterized in that the nozzles ( 6 ) via a common supply line ( 5 ) with the pressure generator unit ( 3 ) are coupled. Device according to one of the preceding claims, characterized in that each nozzle ( 6 ) a nozzle prechamber ( 7 ) is upstream. Apparatus according to claim 14, characterized in that the geometry of the nozzle prechamber ( 7 ) of the nozzle geometry is adjusted. Device according to one of the preceding claims, characterized in that at least one guide device ( 8th ) is arranged on the tube body inner wall. Device according to one of the preceding claims, characterized in that the nozzles ( 6 ) in the guide ( 8th ) and with the supply line ( 5 ) are connected. Device according to one of the preceding claims, characterized in that the tubular body ( 2 ), the pressure generator ( 3 ), the distribution unit ( 4 ) and the supply lines ( 5 ) are formed as a module. Device according to one of the preceding claims, characterized in that the pressure generator ( 3 ) and the distribution unit ( 4 ) form an integral component. Module from pressure generator ( 3 ), Distribution unit ( 4 ) and supply lines ( 5 ) for mounting on a with nozzles ( 6 ) provided tubular body ( 2 ).