Patent GB-653126-A (GB)
Title: Improvements in and relating to centrifugal separators
IPC: B04B11/04
Filed: 1948-07-23
Abstract: 653,126. Centrifugal-separators. BAKER PERKINS, Ltd. July 23, 1948, No. 19733. Convention date, Sept. 19, 1947. [Class 23] A strainer separator, particularly for separating mother liquid from sugar crystals and finally washing the crystals, comprises a rotatable and reciprocatable basket 20 having a rotatable but axially fixed stripping member 28. Both the basket and the stripper are carried by a shaft 26 rotated by a motor 24. The motor is coupled to the shaft by a universal joint 90 and the shaft is supported in bearings 92, 94, the arrangement being that limited horizontal movement may occur at the lower bearing. The stripper is fixed to the shaft and the basket rotates therewith but is axially movable by a fluid-motor 30. Fluid is supplied to the motor 30 by means of a valve 122 and the interior of the shaft so that the basket may be reciprocated whilst rotating. A curb ring 36 is fixed to the stripper by rods 40, 42 and a ring 44. In a modification, Fig. 9 (not shown), the curb ring is carried by rods moved by fluid-motors mounted on a housing surrounding the basket. As shown in Fig. 1 the basket is in position for receiving the charge from a pipe 34, and, after the crystals have deposited, for receiving washing water from a pipe 46. Mother liquid and water pass to a chamber 38 rotating with the basket and having a discharge port in the side wall near the bottom. The port sweeps the entry of a stationary chamber 50 in which a chamber 51 is reciprocated by levers 164 controlled by a fluid-motor. When the chamber 51 is in the position shown in Fig. 1 liquid collects in the chamber 50 from whence it returns to the process, but when the chamber 51 is raised water collects therein and is discharged. At the end of the stripping operation the top of the basket is level with the stripper and the crystals are deposited in a chamber 31 which carries an overflow chamber 190. The chamber 31 has a stationary wall 168 and a rotary bottom-plate 172 driven by a motor 184, a fixed plough discharging the crystals through a spout 32. When in the position shown in Fig. 1 the interior of the basket and bottom of the stripper are periodically cleaned by water sprayed from a retractable pipe 64 into a channel 66 having passages leading to the interior of the basket. The basket has a perforated shell and is lined by spaced rings 80 which carry vertical bars 82. To prevent liquid creeping between the curb ring and the basket rim the basket has a series of holes adjacent the rim. A pump 240, Fig. 10, supplies hydraulic fluid to solenoid operated valves 252, 262, 122 controlling supply of fluid to the fluid-motors 250, 160, 30 which operate a charging valve 35, reciprocate the chamber 51, and reciprocate the basket. A pump 292 supplies water to solenoid operated valves 312, 304 which control supply to the wash pipe 46 and the cleaning pipe 64. A motor 326 drives cams actuating switches S<SP>1</SP>-S<SP>6</SP> at the times required. The closure of the switch 51 energizes a relay CR<SP>1</SP> to actuate switches SW<SP>7</SP>, SW<SP>9</SP>, SW<SP>8</SP> and thus start a timer 350, shut-off the motor 326, and open the valve 35 to charge the basket. At the end of the charging, the timer reverses the switches SW<SP>7</SP>, SW<SP>9</SP>, SW<SP>8</SP> to restart the motor 326 and close the valve 35. A float S<SP>10</SP> in the basket prevents accidental overfilling. After the liquid has been centrifuged from the basket, and collected in the chamber 50, the switch S<SP>2</SP> closes and the chamber 51 is raised. The switch S<SP>5</SP> closes and the crystals deposited in the basket are washed by water discharged from the pipe 46. After a short period the washing is discontinued by opening of switch S<SP>5</SP>, and switch S<SP>6</SP> closes to open a byepass valve 284 to permit the pump motor 242 to idle. After all the washing water has collected in the chamber 51 the switch S<SP>6</SP> closes, and the switch S<SP>2</SP> opens to lower the chamber. The switch S<SP>3</SP> closes to lower the basket to discharge the crystals, and then opens to raise the basket to complete the charge, wash and discharge cycle. During each cycle the switch S<SP>4</SP> controlling the pipe 64 closes whilst the basket is raised but no cleaning water flows until a switch S" is closed. An arm 366 of the switch S<SP>13</SP> is moved by a relay R<SP>1</SP> on the closure of switch S<SP>1</SP>, and is arranged to close the switch after a predetermined number of cycles. During the predetermined cycle the switches S<SP>4</SP>, S<SP>13</SP> are closed so that water is sprayed from the pipe 64 and the chamber 51 is raised to collect the water as it discharges from the basket. The pipe 64 may be caused to discharge at any time by manually operating a switch S". Specification 653,125 is referred to.