1. A fluid bed apparatus for coating solid particles, comprising
a housing having upwardly extending walls surrounding a perforated base plate;
means for providing fluidisation gas through perforations of the base plate for the maintenance of a fluidised layer of particles in the housing;
a displaceable coating nozzle for pressurized atomization of coating liquid, said coating nozzle being provided in at least one of the upwardly extending walls in a channel, the coating nozzle and channel providing co-current introduction of a dispersion gas and coating liquid droplets, the channel debouching into the housing through an orifice having a radius of 5 mm or more via a transition area concentrating gas prior to entry into the fluidised layer, and wherein the coating nozzle is retractable within the channel relative to the orifice to provide dispersion gas assistance in distribution of coating liquid droplets prior to exiting the channel followed by collision with fluidised particles in the housing.
2. The fluid bed apparatus according to claim 1, wherein the orifice has a radius of 10 mm or more.
3. The fluid bed apparatus according to claim 1, wherein the radius of the orifice is in the range of 15 to 250 mm.
4. The fluid bed apparatus according to claim 1, wherein the nozzle tip is retracted 5 to 60 mm.
5. The fluid bed apparatus according to claim 1, wherein two or more nozzles are provided in the upwardly extending walls.
6. The fluid bed apparatus according to claim 1, wherein the channel and the coating liquid nozzle are provided in a pre-existing peephole.
7. The fluid bed apparatus according to claim 1, wherein the nozzle is displaceable in the vertical or horizontal plane.
8. The fluid bed apparatus according to claim 1, wherein the nozzle is turnable in the vertical or horizontal plane.
9. The fluid bed apparatus according to claim 1, wherein the dispersion gas is received from a plenum below the perforated plate.
10. The fluid bed apparatus according to claim 1, wherein the dispersion gas is fed from a separate unit comprising a fan and a heater.
11. The fluid bed apparatus according to claim 1, wherein the radius of the orifice is lesser than the radius of the channel.
12. The fluid bed apparatus according to claim 1, wherein the transition area between the channel and the orifice has a conical form.
13. The fluid bed apparatus according to claim 1, wherein swirl means are used in the channel or at the orifice.
14. The fluid bed apparatus according to claim 1, wherein the housing comprises internal filters retaining particles in the housing.
15. The fluid bed apparatus according to claim 1, wherein the perforated base plate covers substantially the entire area surrounded by the upwardly extending walls.
16. The fluid bed apparatus according to claim 1, wherein the nozzle for pressurized atomization of coating liquid is selected from the group consisting of pressure nozzle, two-fluid nozzle, and three-fluid nozzle.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An exhaust system (1) for an internal combustion engine and comprising:
at least one first high acoustic attenuation path (P1) having a first inlet opening (2) and comprising a muffler (8);
at least one second low acoustic attenuation path (P2) having a second inlet opening (3) and being free from elements or paths suitable for acoustic muffling; and
at least one control valve (4), which is arranged at the second inlet opening (3) of the second path (P2) for controlling the flow of the exhaust gases along the second path (P2),
wherein the control valve (4) comprises:
a baffle (12) which forms a wall of an exhaust gas passage pipe when is in a closing position of the second inlet opening (3);
a shaft (13) which is mounted to rotate about a rotation axis (14) and supports the baffle (12) in order to rotate the baffle (12) itself between the closing position of the second inlet opening (3) and an opening position of the second inlet opening (3); and
an elastic body (15), which is mechanically coupled to the shaft (13) to push the baffle (12) towards the closing position with an elastic force calibrated according to the area of the baffle (12) struck by the exhaust gases and to the working pressure of the exhaust gases, so that when the exhaust gas pressure exceeds a predetermined threshold value, the pneumatically originated force generated by the pressure of the exhaust gases on the baffle (12) is higher than the elastic force generated by the elastic body (15) and the baffle (12) moves to the opening position; and
wherein the first path (P1) comprises at least one first tail (9), which originates from the muffler (8); the second path (P2) comprises at least one second tail (11), which is arranged by the side of the first tail (9) and is directly connected to the second inlet opening (3) by means of a first connecting pipe (10); the control valve (4) comprises a chamber (5) in which the baffle (12) is accommodated; and an initial end of the first connecting pipe (10) is arranged inside the chamber (5) of the control valve (4) and forms the second inlet opening (3) of the second path (P2).
2. An exhaust system (1) according to claim 1, wherein the shaft (13) which is keyed onto one end of the baffle (12), is arranged upstream with respect to the flow direction of the exhaust gases.
3. An exhaust system (1) according to claim 1, wherein the shaft (13) of the control valve (4) has an external end which protrudes outside the exhaust gas passage pipe and is mechanically coupled to the elastic body (15).
4. An exhaust system (1) according to claim 3, wherein the control valve (4) comprises a pivoting lever (16), which is arranged outside the exhaust gas passage pipe, is keyed onto the external end of the shaft (13), and is mechanically coupled to the elastic body (15).
5. An exhaust system (1) according to claim 4, wherein the elastic body (15) is a spiral spring having a first end integral with the pivoting lever (16) and a second end integral with a fixed point.
6. An exhaust system (1) according to claim 5, wherein the control valve (4) comprises a fixed arm (17), which is secured to a wall of the exhaust gas passage pipe and receives the second end of the elastic body (15).
7. An exhaust system (1) according to claim 1, wherein the control valve (4) comprises a limit stop (18), which defines the closing position and forms a wall of an exhaust gas passage pipe.
8. An exhaust system (1) according to claim 1, wherein the first path (P1) comprises a pair of first tails (9), which originate from the muffler (8) and are arranged on opposite sides of the muffler (8), and the second path (P2) comprises a pair of second tails (11), each of which is arranged by the side of a first tail (9) and is directly connected to the second inlet opening (3) by means of a first connecting pipe (10).
9. An exhaust system (1) according to claim 8, wherein the control valve (4) comprises a chamber (5) wherein the baffle (12) is accommodated; two initial ends of the first two connecting pipes (10) are arranged reciprocally side-by-side within the chamber (5) of the control valve (4) and form the second inlet opening (3) the second path (P2).
10. An exhaust system (1) according to claim 9, and comprising a second connecting pipe (7) which has a final end leading into the muffler (8), and an initial end which is arranged inside the chamber (5) of the control valve (4) over the initial ends of the first two connecting pipes (10) and forms the first inlet opening (2) of the first path (P1).
11. An exhaust system (1) according to claim 10, wherein in the closing position, one free end of the baffle (12), opposite to the end integral with the shaft (13), is aligned with a separation line between the initial ends of the two first connecting pipes (10) and the initial end of the second connecting pipe (7).
12. An exhaust system (1) according to claim 1, and comprising a second connecting pipe (7) which has a final end which leads into the muffler (8), and an initial end which is arranged inside the chamber (5) of the control valve (4) over the initial end of the first connecting pipe (10) and forms the first inlet opening (2) of the first path (P1); in the closing position, a free end of the baffle (12), opposite to the end integral with the shaft (13), is aligned with a separation line between the initial end of the first connecting pipe (10) and the initial end of the second connecting pipe (7).
13. An exhaust system (1) according to claim 1, wherein the first connecting pipe (10) passes through the muffler (8) to be mechanically supported by the muffler (8) without any functional relationship with the muffler (8) itself.
14. An exhaust system (1) according to claim 9, and comprising a first connecting pipe (6) which connects the chamber (5) of the control valve (4) to an exhaust line of the internal combustion engine and leads into the chamber (5) at the side opposite to the baffle (12) of the initial ends of the first and second connecting pipes (10, 7).
15. An exhaust system (1) for an internal combustion engine and comprising:
at least one first high acoustic attenuation path (P1) having a first inlet opening (2) and comprising a muffler (8);
at least one second low acoustic attenuation path (P2) having a second inlet opening (3) and being free from elements or paths suitable for acoustic muffling; and
at least one control valve (4), which is arranged at the second inlet opening (3) of the second path (P2) for controlling the flow of the exhaust gases along the second path (P2),
wherein the control valve (4) comprises:
a baffle (12) which forms a wall of an exhaust gas passage pipe when is in a closing position of the second inlet opening (3);
a shaft (13) which is mounted to rotate about a rotation axis (14) and supports the baffle (12) in order to rotate the baffle (12) itself between the closing position of the second inlet opening (3) and an opening position of the second inlet opening (3); and
an elastic body (15), which is mechanically coupled to the shaft (13) to push the baffle (12) towards the closing position with an elastic force calibrated according to the area of the baffle (12) struck by the exhaust gases and to the working pressure of the exhaust gases, so that when the exhaust gas pressure exceeds a predetermined threshold value, the pneumatically originated force generated by the pressure of the exhaust gases on the baffle (12) is higher than the elastic force generated by the elastic body (15) and the baffle (12) moves to the opening position;
wherein the first path (P1) comprises a pair of first tails (9), which originate from the muffler (8) and are arranged on opposite sides of the muffler (8), and the second path (P2) comprises a pair of second tails (11), each of which is arranged by the side of a first tail (9) and is directly connected to the second inlet opening (3) by means of a first connecting pipe (10).
16. An exhaust system (1) according to claim 15, wherein the control valve (4) comprises a chamber (5) wherein the baffle (12) is accommodated; two initial ends of the first two connecting pipes (10) are arranged reciprocally side-by-side within the chamber (5) of the control valve (4) and form the second inlet opening (3) the second path (P2).
17. An exhaust system (1) according to claim 16, and comprising a second connecting pipe (7) which has a final end leading into the muffler (8), and an initial end which is arranged inside the chamber (5) of the control valve (4) over the initial ends of the first two connecting pipes (10) and forms the first inlet opening (2) of the first path (P1).
18. An exhaust system (1) according to claim 17, wherein in the closing position, one free end of the baffle (12), opposite to the end integral with the shaft (13), is aligned with a separation line between the initial ends of the two first connecting pipes (10) and the initial end of the second connecting pipe (7).
19. An exhaust system (1) according to claim 16, and comprising a first connecting pipe (6) which connects the chamber (5) of the control valve (4) to an exhaust line of the internal combustion engine and leads into the chamber (5) at the side opposite to the baffle (12) of the initial ends of the first and second connecting pipes (10, 7).