Centrifugal separator or decanter having an electromagnetic closing system

Abstract

A centrifugal separator has a rotary drum that is adapted to receive a product that can be separated into a light phase, a heavy phase, and solid sediments, a first outlet for the light phase, a closing device that opens and closes a second outlet for the heavy phase. The closing device has an electromagnetic actuator having a ferromagnetic element whereon a closing plug is mounted. The electromagnetic actuator has an electromagnetic coil that creates a magnetic field so as to attract the ferromagnetic element. A spring is connected to the closing plug so as to urge the closing plug to a closed position. The closing plug, the ferromagnetic element and the spring are connected to the rotary drum.

Claims

1. A centrifugal separator or decanter comprising: a rotary drum that is adapted to receive a product that is to be separated at least into a light phase and a heavy phase and solid sediments; a first outlet for the light phase; a closing device that opens or closes a second outlet for the heavy phase or a service outlet of the light phase or a third outlet for the solid sediments, said closing device comprising: an electromagnetic actuator having a ferromagnetic element whereon a closing plug is mounted and an electromagnetic coil that creates a magnetic field when powered so as to attract the ferromagnetic element; and a spring connected to said closing plug so as to urge said closing plug to a closed position, said electromagnetic coil being mounted on a support connected to a fixed structure, said closing plug and said ferromagnetic element and said spring being connected to said rotary drum, said spring comprising: a cup spring having a truncated conical shape.

2. A centrifugal separator or decanter comprising: a rotary drum that is adapted to receive a product that is to be separated at least into a light phase and a heavy phase and solid sediments; a first outlet for the light phase; a closing device that opens or closes a second outlet for the heavy phase or a service outlet of the light phase or a third outlet for the solid sediments, said closing device comprising: an electromagnetic actuator having a ferromagnetic element whereon a closing plug is mounted and an electromagnetic coil that creates a magnetic field when powered so as to attract the ferromagnetic element; a spring connected to said closing plug so as to urge said closing plug to a closed position, said electromagnetic coil being mounted on a support connected to a fixed structure, said closing plug and said ferromagnetic element and spring being connected to said rotary drum; and a collar disposed at an upper end of said rotary drum, said collar comprising holes in communication with said second outlet and an annular seat wherein said closing device is disposed such that said closing plug can open or close the holes of said collar.

3. The centrifugal separator or decanter of claim 2, said rotary drum comprising: a mobile bottom and an upper part that are mutually joined, said mobile bottom being mobile with respect to said upper part in such manner to define said third outlet in a peripheral portion of said rotary drum; and a lower portion disposed around said mobile bottom to define an air space adapted to be filled with water to move said mobile bottom towards said upper part and to close said third outlet, said lower portion comprising outlet holes in communication with said air space so as to let water out in order to move said mobile bottom away from said upper part and to open said third outlet, wherein said closing device is disposed under said lower section in such manner to close or open said outlet holes.

4. The centrifugal separator or decanter of claim 2, wherein said rotary drum comprises a lower part and an upper part that are mutually joined, said third outlet being in a peripheral portion of said rotary drum between said upper part and said lower part.

5. The centrifugal separator or decanter of claim 4, wherein said closing plug is connected to said ferromagnetic element by a plurality of stems sliding in holes formed in said lower part of said rotary drum, wherein helicoidal springs are cooperative with said plurality of stems.

6. A centrifugal separator or decanter comprising: a rotary drum that is adapted to receive a product that is to be separated at least into a light phase and a heavy phase and solid sediments; a first outlet for the light phase; a closing device that opens or closes a second outlet for the heavy phase or a service outlet of the light phase or a third outlet for the solid sediments, said closing device comprising: an electromagnetic actuator having a ferromagnetic element whereon a closing plug is mounted and an electromagnetic coil that creates a magnetic field when powered so as to attract the ferromagnetic element; a spring connected to said closing plug so as to urge said closing plug to a closed position, said electromagnetic coil being mounted on a support connected to a fixed structure, said closing plug and said ferromagnetic element and spring being connected to said rotary drum; and a rotary shaft provided with a flange fixed to said rotary drum, wherein said second outlet is in said flange, said ferromagnetic element connected to said rotary shaft.

7. The centrifugal separator or decanter of claim 6, said flange having said first output and said service output disposed in a peripheral position with respect to the first output, wherein said closing device is applied to said service outlet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics of the invention will appear clearer from the detailed description below, which refers to merely illustrative, not limitative, embodiments, illustrated in the attached drawings, wherein:

(2) FIG. 1 is an axial sectional view of a vertical centrifugal separator according to the prior art;

(3) FIG. 2 is an axial sectional view of a portion of a vertical centrifugal separator according to the present invention, with the closing device of the heavy phase in open position;

(4) FIG. 3 is the same view as FIG. 2, except for the closing device of the heavy phase in closed position;

(5) FIG. 4 is an axial sectional view of a portion of a vertical centrifugal separator according to the present invention, with closing device of solid sediments in closed position;

(6) FIG. 5 is the same view as FIG. 4, except for the closing device of solid sediments in open position;

(7) FIGS. 6 and 7 are the same views as FIGS. 4 and 5, except for they show a variant of the closing device;

(8) FIG. 8 is an axial sectional view of a portion of a horizontal centrifuge or decanter according to the present invention, with closing device of the heavy phase in open position;

(9) FIG. 9 is the same view as FIG. 8, except for the closing device of the heavy phase in closed position;

(10) FIG. 10 is an axial sectional view of a portion of a horizontal centrifuge or improved decanter, with closing device according to the present invention applied to a service outlet and shown in closed position; and

(11) FIG. 11 is the same view as FIG. 10, except for the closing device of the service outlet in open position;

(12) FIGS. 12 and 13 are the same views as FIGS. 10 and 11, except for they show a variant of the improved decanter of FIGS. 10 and 11.

DETAILED DESCRIPTION OF THE INVENTION

(13) Referring now to FIGS. 2 to 5, a first embodiment of a vertical centrifugal separator according to the invention is described, generally indicated with reference number (100). Hereinafter elements that are identical or similar to the ones described above are indicated with the same reference numbers, omitting their detailed description.

(14) Referring to FIG. 2, the centrifugal separator (100) comprises a drum (1) revolvingly mounted with respect to a vertical axis (Y). A first conduit (11) and a second conduit (13) are coaxially disposed inside the drum (1) in such manner to define a first outlet (U1) between the first conduit (11) and an upper part of the second conduit (13) and a second outlet (U2) between the second conduit (13) and an upper part of the drum (1). The second outlet (U2) is disposed in lower peripheral position with respect to the first outlet (U1). Consequently, the first outlet (U1) is used for the light phase and the second outlet (U2) is used for the heavy phase.

(15) A collar (3) is fixed in the upper part of the drum (1) and provided with an annular flange (30) that protrudes internally to close the outlet (U2) of the heavy phase. The annular flange (30) is provided with holes (31) in communication with the outlet (U2) of the heavy phase. The overflow level of the heavy phase is determined by the so-called adjustment ring, which is interchangeable with rings of different diameters, disposed between the annular flange (30) and the output (U2) of the heavy phase.

(16) The collar (3) is provided with a recessed seat (32) defined by an upper wall (33) disposed at a certain distance from the second conduit (13) that protrudes in upper position from the drum (1). The seat (32) of the collar is shaped as a C and disposed above the annular flange (30). The collar is provided with radial holes (34) in communication with the seat (32).

(17) A closing device, generally referred to with number (4), is provided in the seat (32) of the collar. The closing device (4) comprises a plug (40) and actuation means (M) to actuate the plug (40).

(18) The plug (40) is adapted to close the holes (31) of the collar in communication with the outlet (U2) of the heavy phase. The plug (40) is shaped as an annular plate and made of suitable material to guarantee tightness, such as rubber.

(19) According to the invention, the actuation means (M) comprise an electromagnetic actuator (M) to actuate the plug (40) and open or close the outlet (U2) of the heavy phase.

(20) The electromagnetic actuator (M) comprises a ferromagnetic element (41) directly connected to the plug (40) and an electromagnetic coil (42) mounted on a fixed support (50) connected to a fixed structure (51) of the machine.

(21) The closing device (4) is normally open with excited coil; when the coil (42) is excited, the plug (40) is at a certain distance from the flange (30), thus allowing the heavy phase to come out of the holes (31). Instead, when the coil (42) is not excited, no magnetic field is generated and the spring (43) pushes the ferromagnetic element (41) towards the flange (30) in such manner that the plug closes the holes (31), as shown in FIG. 3.

(22) The ferromagnetic element (41) and plug (40) assembly is maintained in closed position by springs means (43). The spring means (43) are preferably a cup spring with a first end connected to the ferromagnetic element (41) and a second end connected to a support (44) fixed to the upper wall (33) of the collar. In this way, when the coil (42) is excited, the magnetic force pushes the ferromagnetic element (41) overcoming the resistance of the spring (43). Instead, when the coil is not excited, the plug (40) returns to the closing position because of the elastic return of the spring (43).

(23) FIG. 4 illustrates a peripheral portion of the drum (1) wherein solid sediments is deposited. In this case, the drum (1) comprises a mobile bottom (16) and an upper part (17) in mutual contact to close an outlet (U3) of the solid sediments. The mobile bottom (16) moves with respect to the upper part (17) in order to open the outlet (U3) of the solid sediments, as shown in FIG. 5.

(24) A tubular end (6) of the drum, to which the upper part (17) of the drum is fixed, is provided with holes (60) in correspondence of the outlet (U3) to let the solid sediments come out. The tubular end (6) continues with a lower section (61) parallel to the mobile bottom (16) of the drum, in such manner to generate an air space (62) between the mobile bottom (16) of the drum and the lower portion (61) of the tubular end (6).

(25) The air space (62) is in communication with vertical holes (63). On the contrary, the air space (62) is not in communication with holes (60) because of a gasket (64) disposed between the mobile bottom (16) of the drum and the lower portion (61) of the same drum.

(26) The air space (62) is used for the hydraulic actuation of the mobile bottom (16) of the drum. In fact, when the air space (62) is filled with water, pressure is generated by centrifugal force and the mobile bottom (16) of the drum is stopped against the upper part (17) of the drum, thus closing the outlet (U3) of the solid sediment. Instead, when water is emptied from the air space (62) (FIG. 5), the mobile bottom (16) of the drum is lowered by means of the internal pressure generated by the fluid in centrifugation inside the drum and is detached from the upper part (17) of the drum, thus opening the outlet (U3) of the solid sediments.

(27) In such a case, the closing device (4a) is disposed under the drum (1) and the plugs (40) close the holes (63) to discharge water.

(28) Therefore, the closing device (4a) is normally closed (FIG. 4) during the operation of the machine and is opened (FIG. 5) only periodically to discharge solid sediments.

(29) Consequently, when the coil (42) is excited, it generates a magnetic field that attracts the ferromagnetic element (41) against the force of the spring (43), thus opening the holes (63) and discharging the water.

(30) FIGS. 6 and 7 disclose a second embodiment of a centrifugal separator with vertical axis (200), wherein the hydraulic actuation of the outlet (U3) of solid sediments has been eliminated. In such a case, the drum (1) comprises an upper part (17) and a lower part (106) that are mutually joined and form an outlet (U3) of solid sediments.

(31) The lower part (106) of the drum is provided with holes (260) in communication with the outlet (U3) to discharge solid sediments.

(32) Moreover, the lower part (106) comprises: an upper annular seat (261) open on top, a lower annular seat (263) open on the bottom; and a plurality of vertical holes (262) providing communication between the two seats (261, 263).

(33) In this way a first stop surface (264) is generated between the upper annular seat (261) and the vertical holes (262) and a second stop surface (265) is generated between the lower annular seat (263) and the vertical holes (262).

(34) In this case, the shape of the closing device (4b) is slightly different from the closing device (4a) of FIGS. 4 and 5.

(35) In fact, the closing device (4b) comprises an annular plug (240) connected to the annular ferromagnetic element (41) by means of a plurality of stems (245).

(36) The plug (240) slides in the upper annular seat (261) and stops against a gasket (G) disposed in the upper part (17) of the drum, in correspondence of the outlet (U3) of solid sediment.

(37) The stems (245) slide in the vertical holes (262) and the ferromagnetic element (41) slides in the lower annular seat (263). A series of helicoidal springs (243) is disposed in the upper annular seat (261), one spring for each stem (262). In view of the above, each helicoidal spring (243) has a first end stopped against the stop surface (264) and a second end stopped against the plug (240), thus stressing the plug in closed position.

(38) The coil (42) is disposed under the ferromagnetic element (41) and supported by a fixed support (50). So, when the coil (42) attracts the ferromagnetic element (41), the outlet (U3) of the solid sediments is opened, as shown in FIG. 7.

(39) FIGS. 8 and 9 disclose a decanter (300) comprising a drum (1) revolvingly mounted with respect to a horizontal axis (X). The drum (1) is composed of a (possibly hollow) rotary shaft (310) provided with a flange (319) fixed to the drum.

(40) The flange (319) is provided with outlet holes of the light phase (U1) and outlet holes of the heavy phase (U2) disposed in peripheral position with respect to the ones of the light phase (U1). The outlet holes of the light phase (U1) are of straight overflow type, in communication with the internal part of the drum that is closer to the axis of the drum; whereas the outlet holes of the heavy phase (U2) are of inverted overflow type in order to act as siphon in the peripheral part of the drum. The outlet holes of the light and heavy phase (U1; U2) are in communication with separate collection chambers.

(41) In such a case, the closing device (4) is mounted on the rotary shaft (310) in external position on the drum (1). The support (44) of the cup spring (43) is a collar mounted on the shaft (310). The spring (43) supports the ferromagnetic element (41) whereon the plug (40) is mounted to open and close the outlet of the heavy phase (U2). The electromagnetic coil (42) is mounted on a support (50) fixed to the fixed structure (51) of the machine.

(42) The plug (40) is normally open (FIG. 8) when the coil (42) is electrically powered. When the coil (42) is not electrically powered, the ferromagnetic element (41) is pushed together with the plug (40) towards the outlet holes of the heavy phase (U2) because of the spring (43).

(43) FIGS. 10 and 11 disclose an improved decanter (400) provided with outlet holes of the light phase (U1) on the flange (319) connected to the rotary shaft (310).

(44) If any, the outlet of the heavy phase (U2) is obtained by means of a radial pipe in association with an obturating disk (480) inside the drum, disposed immediately upstream said pipe in the outlet flow.

(45) Said decanter (400) is provided with a service opening (U4) situated in the end flange of the drum, in peripheral position with respect to the outlet of the light phase (U1). The closing device (4) is applied to the service outlet (U4) in order to open and close said service outlet.

(46) The closing device (4) is normally closed (FIG. 10) during the process and is opened (FIG. 11) to empty the light phase without the need to introduce water.

(47) Referring to FIGS. 10 and 11, if the outlet of the heavy phase (U2) is not provided, although the obturating disk (480) is provided, a two-phase decanter is obtained. A two-phase decanter is provided with two outlets: an outlet (U1) of the liquid light phase, and an outlet of the solid phase that is discharged through a screw inside the drum. As it is known, in a two-phase decanter, the outlet of the solid phase also includes the liquid of the heavy phase, meaning that oil pomace (coming out from the solid phase outlet) has higher humidity than the oil pomace of the three-phase decanter illustrated in FIGS. 10 and 11.

(48) FIGS. 12 and 13 illustrate a different version compared to FIGS. 10 and 11, wherein the outlet of the heavy phase (U2) is not obtained by means of the radial pipe, but with holes obtained on the flange (319) joined to the rotary shaft (310) in peripheral position with respect to the service outlet (U4).

(49) Numerous variations and modifications can be made to the present embodiments of the invention, within the reach of an expert of the field, while still falling within the scope of the invention described in the enclosed claims.