JPH0227106A - Device for separating soot from exhaust gas of internal combustion engine - Google Patents

Abstract

PURPOSE: To separate fine soot particles by forming a capature chute continuing with an outer arcuate portion of a passageway comprising an inner arcuate portion and the outer arcuate portion. CONSTITUTION: A meandrous exhaust gas passageway 1 having an outerarcuate portion 2 and an inner arcuate portion 3 is provided. A soot capture chute 5 is arranged continuously with the outer arcuate portion 2, and an inlet slot 6 is formed towards the flowing direction of exhaust gas. Soot particles in the exhaust gas flow from the inlet slot 6 into the capture chute 5 due to a centrifugal force. As a consequence, the extremely fine soot particles can be separated from the exhaust gas.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for separating soot from the exhaust gas of an internal combustion engine, in particular a diesel engine.

1. Prior Art The separation of soot from the exhaust gases of internal combustion engines is carried out in practice by filters in the form of surface filters or deep bed filters, or by means of cyclone separators, most often interconnected in registers.

20 filters are subject to clogging, which requires tedious cleaning procedures or replacement of the filter cartridge. In the cyclone separator, relatively thick critical particles at 30 μm become an obstacle. Therefore, when using a cyclone separator, the particulate component of the soot must first be enlarged by agglomeration. This requires complicated measures, for example in the form of a coagulating electrode connected to a corona voltage.

OBJECTS OF THE INVENTION It is an object of the invention to provide a simple device for separating soot from the exhaust gas of internal combustion engines, which also separates particulate soot components and which operates reliably and without clogging.

Arrangement of the Invention 1'' The device according to the invention is provided with a tortuous flow channel with wall elements forming an outer arc and an inner arc, and a soot capture chute of approximately round chute cross section, in which the soot Capture shoe) G It forms an inner arcuate portion on the side.

In this case, a flow guide plate may be connected to the soot trap in the area of the inlet slot. According to an advantageous embodiment of the invention, the wall element and the soot catcher chute are arranged vertically. Tortuous means a wave-shaped flow course or a modified flow course.

1. Within the scope of the invention, the configuration of the flow passage and the soot capture chute is such that the vortices generated in the soot capture chute have sufficient kinetic energy so that the soot particles in the exhaust gas stream are crushed by centrifugal force. The soot particles settle as they are transported to the walls of the capture chute. Obviously, the cross-section of the soot capture chute is open on at least one side so that the incoming exhaust gas can flow through the soot capture chute. Other basic laws of flow and aerodynamics should be considered during configuration.

1. An arrangement of the invention in which the soot capture chute has a diameter approximately equal to the width of the flow passage has been found to be advantageous.

The number of flow passages is such that it can absorb the exhaust gas flow rate to be treated. In this case, if the flow rate varies significantly depending on the rotational speed of the internal combustion engine, a configuration having the following characteristics may be advantageous. That is, the flow channel has a closing element on the inlet side that is actuatable by the control device;
Depending on the rotational speed of the internal combustion engine, the number of flow channels opened by the control device is variable.

10 The soot separated in the soot capture chute sinks downward in the soot capture chute. Here the separated soot can be collected. disposing a soot combustion chamber under the soot trap, the soot combustion chamber having at least one ignition pressure and support electrode connected to a combustion voltage source;
This ignition and support electrode initiates and assists in the combustion of the soot.

The advantages obtained are as follows. Thus, with the device according to the invention, soot can be easily separated from the exhaust gas of an internal combustion engine, with even very fine soot particles being separated. The soot capture chute then operates advantageously, but surprisingly does not suffer from the critical particle problems associated with cyclone separators. This is based on the fact that the soot capture chute has a correspondingly small diameter and that flow conditions are created within the soot capture chute that favor the separation of the finer soot particles. The length of the flow passages, and thus the number and diameter of the soot capture chutes, are configured to sufficiently remove soot from the exhaust gases exiting the device according to the invention.

ltl Example Embodiments of the present invention will be described in detail below with reference to the drawings.

The apparatus shown in FIG. 1 is used for separating soot from the exhaust gas of internal combustion engines, particularly diesel engines. The device consists of a tortuous flow channel 1 with wall elements 4 forming an outer arc 2 and an inner arc 3, and a soot capture chute 5, which in this example has a round chute cross section. The layout is as follows. That is, the soot 2j+ capture chute 5 is arranged following the outer arc 2 in the direction of the flow of the exhaust gas. These soot capture chutes have longitudinally extending inlet slots 6 which are open in the direction of exhaust gas flow. These soot catcher chute also form an inner arc 3 on the side of the flow channel. In this embodiment, a flow guide plate 7 is connected to the soot capture chute 5 on the inlet side. The height of the wall element 4 and thus of the flow channel 1 and the soot capture chute 5 is determined 11) according to predetermined conditions. Generally, this height is several times the width B of the flow channel 1.

In this embodiment and according to an advantageous embodiment of the invention, the wall element 4 and the soot catcher chute 5 are arranged vertically.

The soot trapping chute 5 is open at the top and bottom. These soot capture chutes have a diameter approximately equal to the width B of the flow passage 1 in this example, but not by way of limitation.

On the left side of FIG. 1, it is shown how the exhaust gas is supplied. These exhaust gases are transferred to the exhaust gas supply pipe piece 8
and is distributed into the various flow channels 1.

The flow channels 1 can be constructed in such a way that they have a closing element 9 on the inlet side which can be actuated by a control device, and the number of open flow channels 1 is variable depending on the rotational speed of the internal combustion engine and thus on the exhaust gas flow rate. It is clear that it can be arranged as follows.

The soot separated in the soot capturing chute 5 sinks downward. This soot is collected below and, for example, introduced into a soot collection chamber. However, by placing a soot combustion chamber 10 under the soot capture chute 5,
It may also have at least one ignition and support electrode 11 connected to a combustion voltage source. FIGS. 2 and 3 show such a soot combustion chamber 10. FIG. A soot inlet tube 12 is shown on the lid 13 of the combustion chamber 10. One or more soot capture chutes can be connected to such a soot inlet 1" tube piece 12. The ignition and support electrodes 11 are arranged insulated. The separated soot is trapped between the ignition and support electrodes 11. The ignition and support electrode 11 is connected to a combustion voltage source.The soot is deposited to a predetermined height.

The arc is then ignited and the soot burns.

During soot combustion, the electrode continues to act as a support electrode for combustion. It is clear that the exhaust gas is sufficiently oxygenated.

[Brief explanation of the drawing]

1 is a plan view of the device according to the invention, FIG. 2 is a vertical section through a part of the soot combustion chamber that can be arranged below the device according to the invention, and FIG. 3 is a top view of the device according to FIG. It is a top view with the upper part removed.

Claims (5)

[Claims] (1) a tortuous flow passage (1) with a wall element (4) forming an outer arc (2) and an inner arc (3);
and a soot catcher chute (5) of approximately round chute cross section is provided, the soot catcher chute (5) being arranged following the outer arc (2) in the direction of the flow of the exhaust gas and having a substantially round chute cross section. An internal combustion engine, in particular an internal combustion engine, characterized in that it opens a longitudinally extending inlet slot (6) in the direction of gas flow and forms an inner arc (3) on the side of the flow channel. A device that separates soot from diesel engine exhaust gas. 2. The device of claim 1, wherein the wall element (4) and the soot capture chute (5) are arranged vertically. 3. The device of claim 1 or 2, wherein the soot capture chute (5) has a diameter (D) approximately equal to the width (B) of the flow passageway (1). (4) the flow passages (1) have a closing element (9) on the inlet side operable by the control device and the number of flow passages (1) opened by the control device according to the rotational speed of the internal combustion engine; 4. The device according to claim 1, wherein: is variable. (5) Below the soot capture chute (5) is the soot combustion chamber (10
), the soot combustion chamber is arranged with at least one ignition and support electrode (11) connected to a combustion voltage source.
5. The device according to one of claims 1 to 4, having: