Abstract:
A cyclone separator including a gas inlet, a gas outlet, and a particle outlet opening, wherein a rotatable particle collection chamber is in fluid communication with the particle outlet opening.

Description:
BACKGROUND 
   The present invention relates to a cyclone separator. More particularly, it relates to a cyclone separator which includes a rotating collection chamber for collecting the solid particles that exit the bottom of the cyclone separator. 
   It is well known that many, if not most, particles that escape from a cyclone have been effectively separated from the gas stream, fall to the bottom of the separator, and then are re-entrained in the gas stream. 
   SUMMARY 
   The present invention provides a rotating collection chamber for collecting the solid particles that are separated from the gas stream in the cyclone separator. The centrifugal force imparted on the particles by the rotating chamber throws the particles to the outside of the chamber, further separating them from the gas stream, and thereby greatly reducing re-entrainment of the particles. 
   In addition, rotating the collection chamber in the same direction in which the gas is rotating in the cyclone improves the gas flow patterns, which further improves the collection efficiency. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view, partially broken away, of a cyclone separator with a rotating collection chamber made in accordance with the present invention, with the flow path of the gas inside the cyclone shown in phantom; 
       FIG. 2  is an enlarged view of the bottom portion of  FIG. 1 , showing the rotating collection chamber inside a protective housing; 
       FIG. 3  is similar to  FIG. 2  except the rotating collection chamber is not enclosed in a protective housing and has a clean-out door for removing the particles; and 
       FIG. 4  is a view of an easily removable collection chamber for use in the embodiment of  FIG. 1 . 
   

   DESCRIPTION 
     FIGS. 1 and 2  show an example of a cyclone separator  10  made in accordance with the present invention. The cyclone separator  10  has a continuous side wall  11 , which has a substantially circular cross-section and defines a central vertical axis  13 . The side wall  11  defines a tangential inlet  12  to allow a particulate laden gas, such as air, to enter the body of the cyclone separator  10 . The side wall  11  of the cyclone separator  10  includes an upper cylindrical section  14 , an intermediate frustroconical section  16  (hereinafter referred to simply as the conical section  16 ), and a lower cylindrical section  18 , so the cyclone tapers from a larger diameter on top to a smaller diameter at the bottom. A circular, solids outlet opening  22  is located at the bottom of the lower cylindrical section  18 . A cylindrical, clean-gas-outlet  28  is located at the top of the cyclone separator  10 . Typically, particulate laden gas is drawn into and through the cyclone separator  10  by a fan (not shown) located downstream of the cyclone separator  10  and connected to the outlet  28 . 
   As the particulate laden gas enters the cyclone separator  10  through the tangential inlet  12 , a swirling action (or vortex) is induced in the gas. As more gas enters the cyclone separator  10 , it displaces the gas already in the cyclone separator  10 , causing it to move downwardly along the inside surface  26  of the side wall  11  of the conical section  16 . This creates a downwardly spiraling vortex  24 . As the cross-sectional area of the conical section  16  decreases, the velocity of the gas flow increases, and the centrifugal forces acting on the dust particles carried by the gas flow force these particles against the inside surface  26  of the conical section  16 . These dust particles fall down along the inside surface  26 , and, in a properly sized and designed cyclone separator  10 , these dust particles fall into the cylindrical section  18  and exit the cyclone separator  10  through the solids outlet opening  22 , while the clean gas makes a sharp change in direction and flows upwardly along the central axis  13  of the cyclone separator  10  and out through the outlet  28 . 
   Referring now to  FIGS. 1 and 2 , just below the solids outlet opening  22  of the cyclone separator  10  is a cylindrically-shaped particle collection chamber  30 , including a sidewall  32  and a closed bottom  34 , and defining a top opening  36 . The lower cylindrical section  18  of the cyclone separator  10  extends through this top opening  36 , as shown in  FIG. 2 . The inside diameter of the collection chamber  30  is larger than the outside diameter of the solids outlet opening  22  at the bottom end of the lower cylindrical section  18  of the cyclone separator  10 . The height of the collection chamber  30  preferably is at least as great as the inside diameter of the solids outlet opening  22 . 
   The collection chamber  30  rests on top of a platform  38 , which is supported for rotation by the pillow block bearing  40 , idler roller  42 , and drive roller  44 , which is driven by a motor  46 . The entire collecting chamber  30  with its corresponding rotational support mechanism (including the pillow block  40 , and the idler and drive rollers  42 ,  44  respectively) is housed in an airtight, non-rotating enclosure  48 , which is sealed against the cyclone wall  11  by means of a gasket  11 A. This means that the gas that is flowing downwardly cannot escape out the enclosure  48  and so must turn around and flow upwardly through the center of the cyclone to the gas outlet  28  in order to exit. 
   Since the enclosure  48  is an airtight enclosure, it is not necessary to provide an airtight seal at the joint between the rotating collection chamber  30  and the fixed lower cylindrical section  18  of the cyclone separator  10 . Alternatively, as shown in  FIG. 3 , if there is no airtight enclosure present, the junction between the rotating collection chamber  30  and the fixed lower cylindrical section  18  is sealed by means of a seal  50 , which, in this embodiment, is fixed to and rotates with the collection chamber  30 . The seal  50  could, alternatively, be fixed to the cyclone  11 . A wide variety of seal designs may be used for this purpose, as is well-known in the industry. Of course, a seal  50  may be used even when an airtight enclosure  48  is present, if desired. 
   During operation, particle laden gas enters the cyclone separator  10  at the tangential gas inlet  12 , inducing a clockwise vortex  24  (as seen from the top of the  FIG. 1 ). The swirling gas flow gathers speed as it advances down through the frustroconical portion  16  of the cyclone separator  10 , until it reaches the lower cylindrical section  18  and flows into the rotating collection chamber  30  through the solids outlet opening  22 . The gas flow then experiences a sharp change in direction as it reaches the closed bottom  34  of the collection chamber  30 , and then flows upwardly along the vertical axis  13  of the cyclone separator  10  and exits through the gas outlet  28 . 
   Most of the particles that were in the particle-laden gas stream that entered the inlet  12  are separated out by centrifugal force and fall down along the inside of the cyclone wall  11  into the particle collection chamber  30 , where they are flung against the outer wall  32  of the collection chamber  30 , away from the swirling gas stream  24 , so they are not re-entrained into the gas stream  24 . Any particles which are still in the swirling gas stream  24  flow into the collection chamber  30 . The denser particles are immediately flung against the rotating cylindrical wall  32  of the collection chamber  30 , where they are trapped by the centrifugal force pushing them against the wall  32 . Less dense particles may continue to travel downwardly with the gas stream  24  inside the collection chamber  30  until the gas flow makes an abrupt change in direction as it reaches the rotating bottom surface  34  of the collection chamber  30 . Any particles which are unable to make this abrupt change in direction impinge upon the rotating surface  34 , where they too are flung outwardly against the rotating cylindrical wall  32  of the collection chamber  30 . Any particles which are flung against the rotating cylindrical wall  32  of the collection chamber  30  remain trapped there, because the rotating action of the collection chamber  30  imparts a centrifugal force on those particles. 
   Once the collection chamber  30  is sufficiently filled with particles, the particles may be removed. In the embodiment shown in  FIG. 3 , the cyclone separator  10  is shut down, the collection chamber  30  is stopped from further rotation, and a door  23  is opened, in order to allow access to the inside of the collection chamber  30  to remove the particles. 
   Alternatively, in the embodiment of  FIGS. 1 and 2 , the cyclone separator  10  is shut down, the rotation of the platform  38  is stopped, and the collection chamber  30  is removed from the bottom of the cyclone separator  10 . In that case, the collection chamber  30  may be disposed of and replaced with a new collection chamber  30 , or it may be emptied and then re-installed. 
     FIG. 4  shows an example of a collection chamber  30 ′ that would be readily removable. This chamber  30 ′ is made of two parts  30 A,  30 B, which have opposed circular flanges  33 A,  33 B that are clamped together by a clamp  33 . In order to remove the collection chamber  30 ′, the clamp  33  is released, and the lower part  30 B, which holds the particulates, is removed. The lower part  30 B may then be emptied and re-installed, again clamping it to the upper part  30 A, or a new lower part  30 B may be installed. Of course, various other arrangements that allow for easy removal of the collection chamber  30  could be used instead. 
   It will be obvious to those skilled in the art that modifications may be made to the embodiments described above without departing from the scope of the present invention.