Field of the invention

The present invention relates to a system and method for separating particles from polluted gas.

Summary of the invention

The dust separator can be used treating all gases where it is desirable to remove solid particles. It is especially suitable for reducing airborne dust from ovens where wood-firing is used as heating. Each year, more than 1000 persons dies in Norway due to airborne dust in outdoor air, and many cities has forbidden the use of wood-firing. The separator can also be used for cleaning warm industrial gasses having a temperature too high for normal bag filters.

A main object of the present invention is to provide a method and system for efficient separating particles from polluted gas.

Another object of the present invention is to provide a system where the particles and gas are not remixed after being separated.

Yet another object of the present invention is to provide

The principle of the invention is that in a rotating annular chamber where there are particles and gas, the particles will, due to the centrifugal forces, be separated from the gas. The particles will be pushed towards the outer ring and the gas towards the inner ring. To prevent the particles from accumulating towards the outer ring, the ring must be made conical at an angle above 45°, see figure 1 where the angle (10) is indicated, so that the particles move downwards and can be collected.

The invention relates to a dust separator of the kind described in the preamble of claim 1. Reference is made to two inventions of Karl Venas, Norwegian Patent No. NO135695 and NO141147. The new invention has some similarities with NO141147 having the title "Dust separator ". The mode of operation described in the patent NO41147 has the disadvantages in that the separated particles from the two conical shells will lie as airborne dust in the collecting container and can be mixed into the purified gas. In the present invention, separated particles are used by means of the rotational energy guided via a pipe located tangentially at the bottom of the unit. The pipe is connected to a cyclone for collecting the dust particles. In the dust separator of NO141147, the two sealing rings which are located between rotating and stationary parts easily leaks and releases unpurified gas into the collecting container, while in the present invention there is only one sealing ring. If this leaks, pure gas will be sucked in and mixed with the dusty gas l.e. separated particles will not enter the stream of pure gas.

In a first aspect, the present invention relates to a system for separating particles from polluted gas. The system comprises an apparatus, wherein the apparatus comprises a pipe for incoming gas. The pipe is connected to a rotating part or rotor part. The rotating part or rotor part comprises a rotating tube, a conical shell and an annular plate, wherein the annular plate provides a connection between the tube and the conical shell. The apparatus further comprises a conical shell connected to a top plate, wherein the top plate comprises a central cylindrical part pressed into a shaft. The conical shells are mutually concentrically arranged with a gap space arranged between the two conical shells. The conical shells have a cone angle between 30° and 60°. A central hub is connected to the rotating tube and the top plate, respectively. The shaft is further connected to a disk, wherein the disk is connected to an electric motor. The shaft is supported by means of bearings arranged in a bearing housing. The apparatus further comprises a collecting pipe for collecting purified gas from the gap space, the gas from the gap space is guided through apertures located around the periphery of the collecting pipe. The rotating part or rotor part comprises a blade wheel attached to the ring plate. The blade wheel ensures that the incoming gas is in rotation when guided into the gap space between the two conical shells, giving an enhanced separation where a centrifugal force is pressing the particles towards the outer conical shell and separating them from the gas. A dust conveyor is provided for collecting separated particles from the gap space, the dust conveyor is connected to a collection tank for collecting dust particles. The system further comprises a rotor housing with a bottom plate enclosing the apparatus. The rotor housing is connected to the bearing housing and the collecting pipe is centrally arranged on the bottom plate. An outlet pipe is connected to the collecting pipe for outlet of purified gas from the collecting pipe.

Alternatively, the cone angle is 45°. The central hub is rotated by means of the electric motor connected to the shaft.

The dust conveyor is a pipe. The pipe is arranged tangentially on the bottom plate.

The collection tank is a cyclone.

A sealing ring is arranged between rotating parts and fixedly mounted parts.

In a second aspect, the present invention relates to a method for separating particles from polluted gas using the system as described above. The method comprises the steps of: dusty gas enters a pipe, the dusty gas flows into a rotating part and into a blade wheel, and further into a gap space between two conical shells, where the centrifugal force separates the particles from the gas, the purified gas coming out of a lower part of the gap space is guided into the collecting pipe via apertures, the purified gas is discharged through an outlet pipe for the purified gas, the particles coming out at the lower part of the gap space is pushed by the centrifugal force towards the wall of the rotor housing and the rotational energy guides the particles further into a pipe tangentially arranged on the bottom plate of the rotor housing, the pipe guides the particles further to a cyclone for collecting the dust particles.

Brief description of the figures

Embodiments of the present invention will now be described, by way of example only, with reference to the following figures, wherein:

Figure 1 shows schematically an axial section of one embodiment of the invention. The arrows indicated the flow direction of the gas. Dust containing gas enters the pipe (17) and flows into the rotating part (20) into the blade wheel (7) and further into the space (22) between the two conical shells (8) and (9).

Figure 2 shows an enlarged section of figure 1. The arrows indicate the flow direction, the gas enters the pipe (17) and flows into the rotating part (20) into the blade wheel (7), further into the space (22) between the two conical shells (8) and (9).

Figure 3 shows the main parts of the gas separator where fig. 3a is the cover of the rotor housing (14) connected to the drive shaft (2) supported in the bearing housing (3) by means of the bearings (19). Fig. 3b shows the conical shell (9) connected to the shaft (2). Fig. 3c shows the conical shell (8) with the blade wheel (7), see fig. 3e. Further is the screw (5) and the sealing ring (11) shown. The rotating elements are (1), (2), (9) and (8). Fig. 3d apparatus for inlet (17) of gas with particles, outlet (16) of purified gas. The apparatus is fixedly connected to the bottom plate (23) of the rotor housing.

Figure 4 shows a side view of the invention, where separated particles is transported through the transport pipe (15) to the storing cyclone (18).

Figure 5 shows a top view of the invention.

Detailed description of the figures

The figures 1 and 2 shows axial section through one embodiment of the invention. The arrow indicates the flow direction of the gas. Dust containing gas enters the pipe (17) and flows into the rotating part (20) into the blade wheel (7) and further into the gap space (22) between the two conical shells (8) and (9). A sealing ring (11) is arranged in the connection between the fixed pipe (17) and the rotating pipe (20), which can also be combined with a bearing. The blade wheel (7) is connected to the ring plate (25). The ring plate (25) give a connection between the pipe (20) and the conical shell (8). The conical shell (9) is connected to a top plate (21) having a central part (24) which is pressed into the shaft (2) and locked by means of the bolt (4). The rotor part, comprising the pipe (20), the ring plate (25), the conical shell (8) and the blade wheel (7) is connected to the top plate by means of the screw (5). The shaft (2) is connected to a disc (1) connected to an electrical motor (not shown). The shaft (2) is supported by means of the bearings (19) located in the bearing housing (3). The bearing housing (3) is fixedly screwed to the rotor housing (14). The purified gas coming out of the lower part of the gap space (22) is guided into the collecting pipe (13) via apertures (12) which are located around the periphery of the collecting pipe (13) and have an outlet pipe (16) for the purified gas. The particles coming out at the lower part of the gap space (22) will due to the centrifugal force be pushed towards the wall of the rotor housing (14) and will due to the rotational energy be guided further into a pipe (15) located tangentially in the bottom of the unit. The pipe (15) is connected to a cyclone (18) for collecting the dust particles. The cone angle (10) will preferably be between 30° and 60°. The collecting pipe (13) is centrally located on the bottom plate (23) of the motor housing.

Table 1 Disk Shaft Bearing housing Bolt Screw Central hub Blade wheel Conical shell Conical shell 0 Cone angle 1 Sealing ring 2 Apertures 3 Collecting pipe 4 Rotor housing 5 Pipe or dust conveyor 6 Outlet pipe

17 Pipe

18 Cyclone

19 Bearing 0 Rotating pipe 1 Top plate 2 Gap space 3 Bottom plate 4 Cylindrical part 5 Annular plate