Claims:WE CLAIM:

1. A cyclonic pre-separator comprising:

a housing having an inlet and an outlet;

a plurality of cyclone tubes mounted in a parallel configuration in the housing, wherein each cyclone tube of the plurality of cyclone tubes comprises a guiding element that swirls an incoming air stream received from the inlet for separating contaminants by centrifugal force, and wherein filtered air stream exits the cyclone pre-separator through the outlet; and

a plurality of discharge ducts, wherein each discharge duct of the plurality of discharge ducts extends outwardly from a lower end of corresponding cyclone tube of the plurality of cyclone tubes wherein a discharge end of each discharge duct of the plurality of discharge ducts is protruded outwardly from the housing, and wherein each discharge duct of the plurality of discharge ducts discharges the contaminants separated by the corresponding cyclone tube of the plurality of cyclone tubes from the cyclonic pre-separator.

2. The cyclonic pre-separator of claim 1, wherein each discharge duct of the plurality of discharge ducts at the discharge end is provided with a discharge valve that is operated automatically to discharge the contaminants.

3. The cyclonic pre-separator of claim 1, wherein each cyclone tube of the plurality of cyclone tubes is tapered towards an outlet of each cyclone tube.

4. The cyclonic pre-separator of claim 1, wherein each discharge duct of the plurality of discharge ducts is tapered away from the discharge end of each discharge duct.
, Description:FIELD OF THE INVENTION

[001] The present invention generally relates to an air pre-cleaner, and more particularly, relates to a system for multi-cyclone air pre-cleaner.

DESCRIPTION OF THE RELATED ART

[002] Internal combustion engines for automotive vehicles or machines need to be provided with clean air for combustion process. Vehicles and machinery are required to operate in a number of different dusty environments having high amounts of undesirable contaminants such as dust, dirt, water, and the like. Examples of such environments include agricultural machinery, mining equipment and automotive engines used in tropical climates. Engine air filters may be ill-equipped to deal with water or large contaminants. In applications, such as process industries or engines for vehicles, pre-separator devices are used to improve the contaminant removing capacity of the filtration system. Under heavy conditions, a pre-separator may extend the life of an air cleaner filter by three to five times its normal life span.

[003] Traditionally, pre-separators are designed to remove heavier dust particles and debris. This is done so that these heavier impurities do not clog the air cleaner filter which usually has a finer mesh for filtration. By virtue of utilizing such pre-separators, the volume of dirt to be removed by the air cleaner filter is reduced. The most commonly used pre-separator is a multi-cyclone pre-cleaner. The multi-cyclone pre-cleaner is typically employed because of its high capacity and efficiency for removing contaminants. Air stream axially enters into a tapered cyclone cell having a guiding element. The guiding element creates a spinning vortex. The centrifugal force created by the vortex separates dust particles from the air stream, as the air is forced through the tapered cyclone cell. The contaminants are forced from the center of the air stream to the walls of the cyclone cell and are discharged from the cyclone cell through an opening. An outlet tube is positioned within the center of the cyclone cell, and clean air is sucked from the center of the vortex.

[004] In multi-cyclone pre-cleaners, the dirt particles collected by individual cyclones are usually collected in a common discharge area. After the dirt particles have been collected in the common discharge area, the total dirt collected is discharged out of the pre-cleaner using a scavenge port or a discharge port. However, in such an arrangement, there is possibility of formation of vortices in the dust. The centrifugal forces created by the vortices lead to back flow of dust into cyclone cells. Moreover, the vortices may force the dust on to the walls of housing of the pre-cleaner. The back flow of dust may lead to flow of some amount of dust into outlet of the cyclone cells. Also, the dirt particles that stick to the walls of the housing of the pre-cleaner cannot be removed effectively. Moreover, the dust collected in the common discharge area forms lumps, which would be difficult to discharge through the discharge port. The use of common discharge area for discharging dust in the multi-cyclone pre-cleaners leads to a low dirt removing efficiency of the pre-cleaner.

[005] In light of the foregoing, there exists a need for a multi-cyclone pre-cleaner in which the discharged dirt from individual cyclones is not lumped together before removal. Also, there exists a need for a multi-cyclone pre-cleaner that prevents formation of vortices in the dust and achieves high dirt removing efficiency.

OBJECTS OF THE INVENTION

[006] An object of the present invention is to provide a multi-cyclone pre-cleaner with high dust discharge efficiency.

[007] Another object of the present invention is to provide a multi-cyclone pre-cleaner that prevent formation of vortices of dust while discharging the dust.

SUMMARY OF THE INVENTION

[008] The invention discloses a cyclonic pre-separator. The cyclonic pre-separator includes a housing having an inlet and an outlet. The pre-separator further includes a plurality of cyclone tubes that are mounted in a parallel configuration in the housing. Each cyclone tube of the plurality of cyclone tubes comprises a guiding element that swirls an incoming air stream received from the inlet for separating contaminants by centrifugal force, and filtered air stream exits the cyclone pre-separator through the outlet. The pre-separator includes a plurality of discharge ducts. Each discharge duct of the plurality of discharge ducts extends outwardly from a lower end of corresponding cyclone tube of the plurality of cyclone tubes. A discharge end of each discharge duct of the plurality of discharge ducts is protruded outwardly from the housing. Each discharge duct of the plurality of discharge ducts discharges the contaminants separated by the corresponding cyclone tube of the plurality of cyclone tubes from the cyclonic pre-separator.

BRIEF DESCRIPTION OF DRAWINGS

[009] The features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. Embodiments of the present invention will herein after be described in conjunction with the appended drawings provided to illustrate and not to limit the scope of the claims, wherein like designations denote like elements, and in which:
[0010] Fig. 1A is an isometric view of a cyclonic separator, in accordance with an embodiment of the present invention;
[0011] Fig. 1B is a side sectional view of the cyclonic separator, in accordance with an embodiment of the present invention;
[0012] Fig. 1C is an isometric view of outwardly visible components of the cyclonic separator, in accordance with an embodiment of the present invention;
[0013] Fig. 1D is a side sectional view of the cyclonic separator, in accordance with an embodiment of the present invention; and
[0014] Fig. 1E is a top sectional view of the cyclonic separator, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0015] As used in the specification and claims, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “an article” may include a plurality of articles unless the context clearly dictates otherwise.

[0016] Those with ordinary skill in the art will appreciate that the elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated, relative to other elements, in order to improve the understanding of the present invention.

[0017] There may be additional components described in the foregoing application that are not depicted on one of the described drawings. In the event such a component is described, but not depicted in a drawing, the absence of such a drawing should not be considered as an omission of such design from the specification.

[0018] Before describing the present invention in detail, it should be observed that the present invention constitutes dust discharge outlets of a cyclonic separator. Accordingly, the components have been represented, showing only specific details that are pertinent for an understanding of the present invention so as not to obscure the disclosure with details that will be readily apparent to those with ordinary skill in the art having the benefit of the description herein.

[0019] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the invention.

[0020] Figs. 1A – 1E illustrate a cyclonic separator 100. The cyclonic separator 100 may be a pre-separator that is positioned in-line in an air intake system (AIS) of an internal combustion engine. The cyclonic separator 100 is positioned upstream to an air filter (not shown) of the internal combustion engine. The cyclonic separator 100 is in fluid communication with the internal combustion engine through a manifold (not shown). The cyclonic separator 100 is utilized to remove larger contaminants from incoming airflow, such as dirt, dust, water, and the like, while the air filter removes remaining finer particles from the airflow. In an embodiment, the cyclonic separator 100 may be a snorkel or air induction unit that is mounted to trucks or vehicles.

[0021] Fig. 1A illustrates an isometric view of the cyclonic separator 100. The cyclonic separator 100 has a housing 102 having an air inlet 104 and an air outlet 106. The air inlet 104 is an opening through which the incoming airflow is admitted into the air intake system. A longitudinal central axis of the opening of the air inlet 104 is substantially parallel to the ground. This allows the air inlet 104 to prevent the direct entry of rain droplets. The orientation of the air inlet 104 allows the cyclonic separator 100 to easily scoop air when the vehicle is in motion. The air inlet 104 has a screen 108 that prevents entry of solid debris.

[0022] The housing 102 has a very sharp right-angled bend just beyond the air inlet 104. The right-angled bend of the housing 102 may create vortex or swirl of the air, allowing efficient circulation of the air inside the housing 102. The cyclonic separator 100 includes a deflector 110 positioned near the right-angled bend of the housing 102. The deflector 110 is aerodynamically shaped to smooth out the flow of air and reduce the effective restriction of the cyclonic separator 100. The air that enters axially through the air inlet 104 has to take nearly 90 degrees turn at the right-angled bend of the housing 102. The presence of the deflector 110 allows the air to smoothly flow at the right-angled bend of the housing 102. The housing 102 of the cyclonic separator 100 may be structured to separate moisture from the air and collect it in a water trap. The air outlet 106 is in fluid communication with the air filter through the manifold.

[0023] Fig. 1B illustrates side sectional view of the cyclonic separator 100 having four cyclone tubes that are arranged to process particulate laden airflow. The cyclonic separator 100 is a multi-cyclone air pre-cleaner. The housing 102 of the cyclonic separator 100 encloses a plurality of cyclone tubes 112 at the air inlet 104. In an embodiment, the plurality of cyclone tubes 112 are arranged in a parallel configuration. In the parallel configuration, the plurality of cyclone tubes 112 are arranged in rows and extended in vertical direction (Y) with respect to the cyclonic separator 100. The plurality of cyclone tubes 112 are positioned vertically on top of each other. The longitudinal axes of the plurality of cyclone tubes 112 are parallel to the longitudinal axis of the cyclonic separator 100. The adjacent individual cyclone tubes may be in contact with each other or may be spaced apart from each other. In another embodiment, the plurality of cell tubes 112 are arranged in rows and at 45 degrees angle relative to the longitudinal axis of the air inlet 104. The plurality of cyclone tubes 112 includes cyclone tubes that are identical in structure and function.

[0024] Each cyclone tube 112 has an inlet and an outlet. The inlet is at an entry side and outlet is at an exit side of the cyclone tube 112. In an embodiment, each cyclone tube 112 is frusto-conical in shape and is slightly tapered towards its exit side. Each cyclone tube 112 includes a guiding element 114 that is positioned at the entry side of the cyclone tube facing the air inlet 104 of the housing 102. The guiding element 114 includes but is not limited to angular vanes, guide blades or any other relevant spin imparting element. Each cyclone tube 112 further houses a dip tube 116 at its exit side. In an embodiment, the dip tube 116 is a cylindrical tube. In another embodiment, the dip tube 116 is conical in shape as shown in Figs. 1B-1E. Moreover, the dip tube 116 is widened conically in the flow direction of the airflow. The dip tube 116 is axially concentric with the cyclone tube 112. Moreover, the dip tube 116 has a smaller diameter than the cyclone tube 112. The dip tube 116 protrudes inwardly in the cyclone tube at its exit side. The dip tube 116 forms the outlet of the cyclone tube 112.

[0025] As illustrated in Figs. 1B-1E, each cyclone tube of the plurality of cyclone tubes 112 includes a discharge duct 118 through which particulates collected in the cyclone tube 112 are forcibly ejected due to the action of centrifugal force on the swirling air stream in each cyclone tube 112. For discharging the separated particles from the cyclonic separator 100, each discharge duct 118 corresponding to each cyclone tube 112 discharges the dust out of the cyclonic separator 100. Each discharge duct 118 extends perpendicularly relative to the longitudinal axis (X) of the cyclonic separator 100. Specifically, the discharge duct 118 is protruded outwardly from the housing 102 to deliver the dust out of the cyclonic separator 100. The particles emerging from each cyclone tube 112 are discharged therefrom by means of the discharge duct 118 that is oriented downwardly. The dirt particles that have been separated in each cyclone tube 112 can be removed by means of gravity and / or by means of suction. The orientation of the discharge duct 118 can be varied depending on how the dirt particles need to exit from the cyclonic separator 100.

[0026] Each discharge duct 118 has two ends – a connector end and a discharge end. The connector end is the end where the discharge duct 118 protrudes outwardly from the cyclone tube 112. The connector end is an opening formed on the cyclone tube 112 at the space between the inner surface of the cyclone tube 112 and the outer surface of the dip tube 116. The separated dirt particles enter the discharge duct 118 from the cyclone tube 112 at the connector end. In an embodiment of the present invention, the cyclone tube 112 is tapered towards the connector end of the discharge duct 118. Due to the slope or slant surface of the cyclone tube 112 at the connector end of the discharge duct 118 allows the separated dirt to accumulate near the connector end of the discharge duct 118. In another embodiment of the present invention, the discharge duct 118 is tapered away from the discharge end of the discharge duct 118 i.e., towards the connector end of the discharge duct 118. This ensures that great amount of dirt particles enter the discharge duct 118. The separated dirt particles exit the cyclonic separator 100 from the discharge end. The discharge end is directly exposed to the atmosphere.

[0027] In another embodiment of the present invention, a discharge valve is positioned at the discharge end of the discharge duct 118. This helps to control the rate of discharge according to the desired application. The discharge valve can be provided with a sensor which automatically actuates the discharge valve under certain conditions. The sensor includes but is not limited to a weight sensor, a volume sensor and a velocity sensor. The cyclonic separator 100 is designed to provide excellent contaminant removal, while minimizing the pressure drop across the cyclonic separator 100 by reducing the restriction.

[0028] When the engine requires air for combustion, air enters the cyclonic separator 100 through the air inlet 104. The air enters axially into each cyclone tube 112. Up on entry of the air into each cyclone tube 112, the guiding element 114 allows the air to rotate or swirl. The guiding element 114 imposes a helical profile on the air that enters cyclone tube 112. As the incoming air with cyclonic motion enters the continuously narrowing inner surface of the cyclone tube 112, the dirt particles are pushed outwards in a space between the inner surface of the cyclone tube 112 and an outer surface of the dip tube 116 due to venturi effect. Thus, the cyclone tube 112 purifies incoming airflow. The particles contained in the airflow be transported by centrifugal force radially outwards into that space and accumulate there. Moreover, arrangement of the cyclone tube 112 and the dip tube 116 allows the splitting of air flow into a clean air stream and an exhaust air stream. The clean air stream, that is the less particle-laden air, enters from the inside through the dip tube 116, and out of the air outlet 106 of the cyclone tube 112. The exhaust air flow, so the more particle-laden air is discharged by the discharge duct 118.

[0029] Use of the discharge duct 118 for the corresponding cyclone tube 112, prevents formation of vortices in the dust, thereby avoiding the lumping of dirt. The discharge duct 118 per cyclone tube 112 solves the above-mentioned problems by achieving high dirt separation and removal efficiency.

[0030] The present invention has been described herein with reference to a particular embodiment for a particular application. Although selected embodiments have been illustrated and described in detail, it may be understood that various substitutions and alterations are possible. Those having ordinary skill in the art and access to the present teachings may recognize additional various substitutions and alterations are also possible without departing from the spirit and scope of the present invention.