Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B11/00—Feeding, charging, or discharging bowls
  • B04B11/04—Periodical feeding or discharging; Control arrangements therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B13/00—Control arrangements specially designed for centrifuges; Program control of centrifuges
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B9/00—Drives specially designed for centrifuges; Arrangement or disposition of transmission gearing; Suspending or balancing rotary bowls
  • B04B9/10—Control of the drive; Speed regulating

Definitions

• the invention relates to an alarm device on periodically self-cleaning centrifuges for separating liquids of different specific weights, in particular plate centrifuges for use on board ships, in which the centrifuge housing has a sludge outlet.
• Self-cleaning disc centrifuges particularly require monitoring the operating state of the drum after each cleaning process and monitoring the sealing water to ensure that no oil gets out of the centrifuge through the water outlet.
• the drum condition is monitored by arranging a baffle plate on a lever pretensioned by a spring, so that the oil or the like emerging from a drum that is not closed properly hits this baffle plate and triggers an acoustic alarm signal after the spring tension has been overcome by the lever or switches off the centrifuge drive.
• Such an alarm device works imprecisely because a large amount of oil or the like has to escape in order to trigger the alarm and because errors in the adjustment of the spring tension can very easily occur.
• a float control with a flow regulating screw is used to monitor the sealing water, so that adjustment errors lead to the triggering of a false alarm if the drum of the centrifuge fills with sealing water again after the cleaning process and excess sealing water escapes or oil can pass without triggering an alarm.
• mud constantly passes this alarm device, so that the latter must be taken out of operation. This alarm device for the closure water overflow must therefore be carefully observed and kept very clean.
• the invention has for its object to provide a device for maintenance-free monitoring of all operating functions of a centrifuge, in particular a plate centrifuge, with little technical effort.
• the invention solves this problem by designing an alarm device with the features according to the characterizing part of patent claim 1.
• Such an alarm device can be produced inexpensively and its function is extremely reliable.
• Their arrangement at the sludge outlet of the centrifuge housing has the advantage that all of the operating functions to be monitored are carried out at this point and the result is that overflow lines can be connected to the container from the monitoring point.
• the container in turn has an outlet which can advantageously be shut off by a shut-off valve with a motor drive, so that this shut-off valve can be opened and then closed again during each cleaning operation of the centrifuge drum. If large quantities of sludge emerge, this butterfly valve can be opened and closed again at intervals, for example by control by means of a time switch, the periods for this intermediate opening being able to be defined as a function of the quantity of sludge that arises.
• Such a regulation could also be used for centrifuges that are operated manually cleaned and where only the water leakage is to be monitored.
• overflow lines to the tank for monitoring other functions, for example for monitoring the overpressure in the preheater, for monitoring the fill level of sludge tanks into which the sludge flows out of the tank when the butterfly valve is open.
• the alarm switching element can be designed in a manner known per se. For example, switching electrodes which are bridged by the fill level in the container, float circuits or other known means are suitable.
• the mode of operation of the known alarm device is based on the fact that all liquid quantities escaping in the event of malfunction at the locations to be monitored are drained into the container and collect therein.
• the alarm switching element triggers an alarm, for example an acoustic or visual signal, the centrifuge is switched off, the inlet cross-section is shut off, a wake-up call or any other alarm call.
• FIG. 4 shows a side view offset by 90 degrees compared to FIG. 3,
• Figure 5 is a plan view of the container
• Figure 6 is a partial sectional view of the butterfly valve, opened and closed.
• FIGS. 3 and 5 symbolically show two different types of plate centrifuge, such as those used on board ships.
• the housing 1 of the centrifuge has a lateral sludge outlet 2.
• the sludge outlet 2 is provided on the underside of the housing 1.
• the container according to FIGS. 3 to 5 can be screwed to a flange 4.
• the container 3 is accessible through an upper lid 5 with a closure device 6.
• a motor drive 9 for example a magnetic drive or a drive from a hydraulically or pneumatically actuated piston-cylinder unit, which is shown in the drawing is only shown in Figure 3.
• Overflow lines for other monitoring functions can be connected at the points labeled A, B and C.
• a chamber 10 with the alarm switching element is located on the side next to the container 3.
• switching electrodes 11 and 12 are arranged one above the other so that when a level in the container 3 covering the upper electrode 12 is reached, an alarm circuit is triggered, for example the centrifuge drive is switched off and an alarm signal or wake-up call is triggered at the same time.
• a float circuit for the same function described can also be accommodated in the chamber 10.
• the butterfly valve 8 in the outlet of the container 3 is closed. Before the start of the desludging process of the centrifuge drum, the butterfly valve 8 is opened by the drive 9. The now emerging sludge flows into a sludge tank. After the desludging process has ended, the butterfly valve 8 closes again, so that the plate centrifuge resumes normal operation. If the centrifuge drum is not closed properly during this normal operation, 01 or the like flows out of the water outlet via an overflow line into one of the connections A, B or C, so that the container 3 fills until an alarm circuit is triggered via the switching electrodes 11, 12 or the like he follows. The overpressure of the preheater can also be led to one of the connections A, B or C by means of an overflow line.
• Overflow lines are also the Sludge from the centrifuge-receiving tanks can be connected to one of the connections A, B, C or other connections not shown in the drawing, so that when such a tank is overfilled, the overflow quantity is returned to the container 3 and an alarm circuit is triggered when a predetermined fill level is reached triggers. All operational functions of the centrifuge and the units connected to it are monitored by the design according to the invention by means of a single alarm device which is maintenance-free, is robust and can be produced inexpensively.

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• Centrifugal Separators (AREA)

Applications Claiming Priority (2)

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ID=6398709

Family Applications (1)

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Cited By (1)

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Citations (3)

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• 1990
  • 1990-01-25 DE DE19904002073 patent/DE4002073C1/de not_active Expired - Lifetime
  • 1990-12-01 WO PCT/EP1990/002069 patent/WO1991011264A1/de not_active Ceased
  • 1990-12-01 AU AU67530/90A patent/AU6753090A/en not_active Abandoned

Patent Citations (3)

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