Biomass granulator

1. A biomass granulator, comprising a granulation chamber which is provided with a feed inlet ( 5 ) and a discharge outlet ( 6 ), characterized in that the granulation chamber is divided into a primary molding chamber ( 8 ) and a secondary molding chamber ( 9 ) by a ring-shaped die ( 1 ), wherein the secondary molding chamber ( 9 ) is arranged surrounding an outside of the primary molding chamber ( 8 ) and the primary molding chamber ( 8 ) is provided inside with a pressing wheel mechanism comprising a wheel seat ( 2 ) on which at least two eccentric pressing rollers ( 3 ) that are symmetrical are provided; the eccentric pressing rollers ( 3 ) are disposed with a plurality of overlapping threads ( 17 ) are disposed on a surface of each eccentric pressing roller ( 3 ) at an angle with respect to an axis of the rotation of the eccentric pressing rollers ( 3 ); a guide groove ( 18 ) is provided between the adjacent threads ( 17 ) on the surface of each eccentric pressing roller ( 3 ), the guide groove ( 18 ) has a groove's center line obliquely arranged relative to an axis of rotation of the eccentric pressing rollers ( 3 ); the ring-shaped die ( 1 ) is provided outside with a plurality of scrapers ( 4 ) taking the axis of a main shaft ( 7 ) as the axis of rotation, and the contact point of the eccentric pressing roller ( 3 ) and the ring-shaped die ( 1 ) is always located between adjacent scrapers ( 4 );

wherein the biomass granulator further comprises a driving mechanism comprising a scraper's driving device; the scraper's driving device comprises a first motor (a 1 ), a first reducer box (a 2 ) for moving the eccentric pressing rollers ( 3 ) at different speeds, and a first drive gear (a 3 ); wherein the first reducer box (a 2 ) is connected with an output end of the first motor (a 1 ) as well as the first drive gear (a 3 );

wherein the discharge outlet ( 6 ) is provided in the sidewall of an outer shell ( 16 ), and the axial center line of the discharge outlet ( 6 ) is parallel to the plane of rotation of the scraper ( 4 );

the gap distance between the side edge of the scraper ( 4 ) and the inside wall of the secondary molding chamber ( 9 ) is 0 mm˜2 mm.

2. The biomass granulator as claimed in claim 1 , characterized in that, further comprising a rotating tray ( 11 ) which is rotatably arranged relative to the ring-shaped die ( 1 ) with its axis of rotation coinciding with the axis of the ring-shaped die ( 1 ); a scraper ( 4 ) is connected with the rotating tray ( 11 ) below the rotating tray ( 11 ) as well as one output end of the driving mechanism connected with the rotating tray ( 11 ).

3. The biomass granulator as claimed in claim 1 , characterized in that the gap distance between any adjacent eccentric pressing rollers ( 3 ) are equal, and all included angles α formed by a straight line from the axis of rotation of the pressing roller ( 3 ) to the axis of rotation of the wheel seat ( 2 ) and a straight line from the axis of rotation of the pressing roller ( 3 ) to the outermost point on the leading edge or retreating edge of the adjacent eccentric pressing rollers ( 3 ) are equal.

4. The biomass granulator as claimed in claim 1 , characterized in that the scraper ( 4 ) has an angular speed of rotation N times as fast as what the wheel seat ( 2 ) has, wherein N is equal to 1 or 2 or 3 or 4.

5. The biomass granulator as claimed in claim 4 , characterized in that the eccentric pressing roller ( 3 ) has a linear speed of rotation faster than what the scraper ( 4 ) has.

6. The biomass granulator as claimed in claim 2 , characterized in that the driving mechanism further comprises a wheel seat's driving device; and an outer edge of the rotating tray ( 11 ) is provided with teeth engaged with the first drive gear (a 3 ) so that the rotating wheel tray and the first drive gear (a 3 ) are engaged; the wheel seat's driving device comprises a second drive motor (b 1 ), an active drive gear (b 3 ) and a second drive gear (b 4 ), wherein the active drive gear (b 3 ) is connected with the second drive gear (b 4 ) via a transmission gear (b 5 ), the output end of the second drive motor (b 1 ) is connected with the active drive gear (b 3 ) and the second drive gear (b 4 ) is connected at its axis of rotation with the main shaft ( 7 ).

7. The biomass granulator as claimed in claim 2 , characterized in that a support platform ( 12 ) is provided above the ring-shaped die ( 1 ), with a surface of the support platform ( 12 ) in a plane where it is located perpendicular to an inside of the scraper ( 4 ), and support rollers ( 13 ) are provided below the rotating tray ( 11 ) and contact the supporting plane of the support platform ( 12 ).

8. The biomass granulator as claimed in claim 1 , characterized in that the biomass granulator further comprises a material chamber's shell ( 14 ) which is provided above the ring-shaped die ( 1 ), and an inner space of the material chamber's shell ( 14 ) forms a raw material chamber ( 15 ) which connects the feed inlet ( 5 ) and the primary molding chamber ( 8 ).

9. The biomass granulator as claimed in claim 8 , characterized in that the raw material chamber ( 15 ) is provided with a pressing-material tray ( 19 ) which is fixedly connected with the scraper ( 4 ) via a connecting rod, wherein the surface of the pressing-material tray ( 19 ) is disposed with a leaking-material groove ( 19 - 1 ) spirally surrounding the axis of rotation, and the pressing-material tray ( 19 ) is gradually recessed from the axis of rotation toward the direction of the side edge.