Device for separating particles from a gas stream

The invention concerns a device for separating particles from a gas stream, in particular for separating liquid or solid particles, for example, oil or dust, in accordance with the preamble of the independent claim.

DE 190 42 219 A1 discloses, for example, an oil separating device for separating oil from so-called blow-by gases that escape as combustion gases due to leaks in the crankcases of an internal combustion engine. In these oil separators the oil components are separated on flow obstacles on which the oil particles in the gas stream can deposit.

Moreover, DE 103 23 343 A1 discloses a separating device that is of a two-stage configuration and has two cyclone devices connected in series through which the gas stream to be purified passes after it has been caused to rotate by vanes. By means of a matched size relation of the two cyclone devices the volume flow range as well as the separating degree can be affected and the removal of the separated particles can be realized by laterally circumferentially extending annular spaces between an immersion pipe and the housing pipe through which the gas flow passes.

The invention is based on a separating device for separating particles from a gas stream where the gas stream is caused to rotate by means of a guiding device and the liquid or solid particles to be separated are removable by means of an outlet. According to the invention, the separating device is advantageously comprised of a substantially cylindrical or, caused by its manufacture, slightly conical (draft angle) housing pipe with a guiding device and comprised of an immersion pipe that is arranged in alignment with the flow direction of the gas stream in the housing pipe which immersion pipe is externally provided with a spiral for a directed removal of the particles, separated by rotation, to a housing opening and furthermore provided with a central outlet for the gas stream that has been purified.

The housing pipe and the internally positioned immersion pipe are preferably of a cylindrical configuration and generally are mounted in a horizontal position. The particles to be separated can be removed at the bottom.

In that the proposed separating device is provided with an immersion pipe having a spiral contour, the particles to be separated can be removed, guided by means of the spiral, through a correspondingly designed housing opening out of the separating device in a targeted fashion. The circumferentially extending annular and frequently clogging gap between the housing parts that has been used for this purpose in the past is therefore no longer required; this provides a significant improvement of the degree of separation and a reduction of the mounting space for the separating device, in particular when several cyclone devices are arranged in an array. Also, with the invention a reduction of air resistance in the gas stream can be realized easily.

Moreover, the possibility of centering the housing pipe by means of the immersion pipe when assembling the parts is also advantageous for a variety of applications, in particular when the immersion pipe with the spiral tapers conically inwardly and projects into the housing pipe.

According to the invention, on the immersion pipe a guide channel can be formed at the outlet of the spiral in a simple way that, matching the opposite wall of the housing pipe, leads to the housing opening for removal of the separated particles. In a simple way, the guide channel extending to the housing opening can be formed by a slanted portion of a circumferential area of the immersion pipe.

Moreover, it is as advantageous when the guiding device for forcing the rotation of the gas stream and thus for generating the cyclones is formed by a configuration in the form of an upright turbine vane at the end of the housing pipe opposite the immersion pipe at the intake of the gas stream.

An advantageous application of the invention results when an array of separating devices is formed in that a housing part of the array contains a plurality of immersion pipes and, correspondingly, a housing part has a matching number of immersion pipes that can be joined for forming the array.

In particular the separating devices or an array of separating devices can be an oil separator for separating oil in blow-by gases of a crankcase in an internal combustion engine.

The invention will be explained with the aid of the drawings. It is shown in:

FIG. 1 a longitudinal section of a separating device according to the invention with an immersion pipe arranged in a housing pipe;

FIG. 2 a plan view onto the immersion pipe according to FIG. 1 ;

FIG. 3 a perspective view of the immersion pipe according to FIG. 1 ;

FIG. 4 is an arrangement of several immersion pipes according to FIG. 3 as a component of an array; and

FIG. 5 is a schematic diagram illustrating one exemplary application with the separating devices applied to an air intake system and for separating oil from crankcase blow-by gases.

In FIG. 1 a separating device 1 for separating particles from a gas stream 2 is shown in which the gas stream 2 by means of a guiding device 3 , here in the form of an upright turbine vane, is caused to rotate. As a result of rotation of the gas stream 2 the particles 4 to be separated are first forced against the wall of a generally cylindrical housing pipe 5 and then guided to the immersion pipe 6 arranged below.

The immersion pipe 6 has externally a substantially conical configuration, with the exception of the cylindrical areas for centering the housing pipe 5 , and has a spiral 7 by means of which the liquid or solid particles 4 to be separated are guided to a lateral housing opening 8 between the immersion pipe 6 and the housing pipe 5 for a targeted removal of the particles 4 separated by rotation.

The immersion pipe 6 has a central outlet 9 for the gas stream 2 that is now purified. Moreover, the immersion pipe 6 , as mentioned before, tapers with the spiral 7 conically inwardly and projects into the housing pipe 5 .

On the immersion pipe 6 a guide channel 11 at the outlet of the spiral 7 can be formed for a targeted supply of the particles 4 in that a slanted portion 12 of a circumferential area is provided on the immersion pipe 6 , as is shown in particular in the illustration of the immersion pipe 6 according to FIG. 2 and in the perspective illustration according to FIG. 3 .

A further embodiment of the invention is illustrated in FIG. 4 in which an array 13 of separating devices is formed in that a housing part of the array 13 comprises a plurality of immersion pipes 6 and, correspondingly, a housing part (not shown) with a matching number of housing pipes can then be attached. In this connection, the separating device 1 according to FIGS. 1 to 3 or the array 13 of separating devices according to FIG. 4 can be, for example, a dust preseparation arrangement in an air intake system for an internal combustion engine in a motor vehicle.

FIG. 5 is a schematic diagram illustrating one particular application of separating device as claimed in claims 8 and 9 . The separating devices or array of separating devices (such as 13 on FIG. 4 ) is schematically illustrated as may be applied with internal combustion engine 50 . Separating device or devices 42 receive intake are 40 . Purified gas (air with particulates removed) from the central outlet 44 to the air filter assembly 46 , then from the air filter 46 to the engine 50 through intake tract portion 52 . Advantageously, separating device or devices 42 form a dust preseparation arrangement in the air intake tract of internal combustion engine 50 . Also shown is separating device or device 56 applied as an oil separator for separating oil in blow-by gases 54 of a crankcase of internal combustion engine 50 . Blow-by gases 54 flow from the crankcase of engine 50 to the separating device or devices 56 . Oil is removed by separating device or devices 56 and returns 58 to the crankcase of engine 50 . Purified gases flow from the separating device 56 through the central outlet (schematically shown at the bottom of 56 ) and returned into the air intake tract 52 of the engine 50 .