Monitoring Method of Centrifugal Separator for Drum Leakage

Abstract

The present invention relates to a method for monitoring a drum of a centrifugal separator (1) for leakage and includes: A) providing a centrifugal separator (1) with an emptied drum and providing a value of a reference volume of the drum (2); B) measuring, by a measuring device (19), an inflow volume until the reference volume of the drum (2) is reached; C) measuring pressure by a pressure sensor (24) within the phase outlet; D) evaluating a time sequence of measured pressure values after the reference volume is reached to determine a pressure increase; and E) outputting a signal if a pressure increase is determined outside a time interval after the reference volume is reached.

Description

Technical Field

[0001] The present invention relates to a method for monitoring leakage of a drum of a centrifugal separator.

Background Art

[0002] When operating a disk centrifuge, it is advantageous to detect leakage, particularly in the area of the so-called main drum seal. It is desirable to check at least periodically whether there is any leakage inside the drum. This ensures that the separator functions properly and improves overall operational safety.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Based on the above problems, an object of the present invention is to provide a method for monitoring drum leakage during operation, and incidentally quantifying the degree of leakage.

Means for Solving the Problems

[0004] The present invention solves the above object by a method having the features of claim 1.

[0005] The method according to the present invention for monitoring the drum of a centrifuge for leakage has the following steps. A Deploying a centrifugal separator with an emptied drum and supplying a value of the reference volume of the drum. By previously emptying the drum and then measuring and recording the refill, the supply volume of the drum, and the pressure of the product discharge, values can be supplied during a test run or during continuous operation of the separator. In the case of a test run, the provision of the reference volume can be a predetermined design value specified by the manufacturer for the type of separator. Then, step B follows step A. B Measuring the inflow volume by a measuring device until at least the reference volume of the drum is reached.

[0006] In process B, the drum is filled. The inflow volume, in particular the flushing medium, is recorded until the reference volume is reached. However, the measurement is also carried out after the reference volume has been reached, where an increase in pressure is also detected by the sensor and evaluated.

[0007] The flushing medium in the sense of the present invention can be any liquid that does not contain solids, for example replacement water or a phase of the product. If no pressure increase occurs exactly when the reference volume is reached, the determined supply volume can be recorded at the time when the measured value of the pressure increase is recorded. A new reference volume for filling the drum can be determined from this supply volume and stored.

[0008] For example, if the supply volume remains the same and the pressure continues to rise until a constant overpressure is set at the outlet, this is an indication that the drum is tight (leak-free). If no pressure increase is detected at the product outlet of the outflow phase when the reference volume is reached, or if a pressure increase is determined after detection at the time when the reference volume is reached, the volume is flowing out of the drum at another point. In other words, if the pressure increase is only observed later although the reference volume has been reached, the drum is leaking. The step of measuring the pressure by a pressure sensor at the outlet of phase C, the step of evaluating the time sequence of the measured values of the pressure after the reference volume has been reached and thereby determining the pressure increase, and the step of outputting a signal if a pressure increase is determined outside a predetermined time interval after the reference volume has been reached.

[0009] As can be seen from the above description, the individual steps can be carried out simultaneously with each subsequent step or directly integrated into the subsequent steps. Advantageous configurations of the method are the subject matter of the dependent claims.

[0010] The following steps can preferably be used to provide values for the reference volume of the drum when the separator is being commission-tested. I. Providing a predetermined reference volume to a centrifuge separator according to its geometric dimensions; II. Filling the drum and determining the liquid volume required to fill the drum can, corresponding to the currently available empty drum volume of the drum, until the limit level is reached.

[0011] The limit level can be determined, for example, by a pressure sensor or a limit level switch. The corresponding switches are known from process and measurement technology. They can be, for example, vibration switches or capacitance switches. However, a pressure sensor is preferred because it can also be used, for example, to determine the empty volume of the drum as a calibrated reference volume or to quantify the degree of leakage.

[0012] The pressure sensor and / or level switch can be arranged, in particular, at the outlet of the heavier liquid phase or the outlet of the clarified phase of the separator. The liquid introduced to fill the drum is preferably a flushing medium, where the flushing medium inlet of the separator for filling the drum and the product inlet of the separator flow into a common inlet pipe.

[0013] The volume required to fill the drum can advantageously be determined using a flow meter. For a conductive medium such as water, a magnetic induction flow meter is particularly suitable. The flow meter can be arranged in or at the product inlet of the separator and / or, particularly preferably, in or at the flushing medium inlet of the separator.

[0014] When a signal is generated according to process E, the signal generates an output, preferably a warning, at the output unit. Instead of or in addition to this, it can act immediately on the operation of the separator, in particular, start the discharge and / or shutdown of the separator to prevent further loss of product due to leakage and protect the drum from wear.

[0015] Processes A to E can be repeated at least twice, particularly at regular intervals, and after the drum is emptied, filling can be carried out in Process B. At least Processes B to E, preferably all processes, should be carried out while rotating the drum. Another advantage of this method is that measurements can be carried out online during processing without disassembling.

Brief Description of the Drawings

[0016] Further advantages, features, and details of the present invention are shown in the following description, and exemplary embodiments of the present invention are described in more detail with reference to the accompanying drawings. Those skilled in the art may also usefully consider the features disclosed in combination in the drawings, description, and claims, and combine them to form further useful combinations. In particular, within the framework of the present invention, there are numerous possibilities for modifying and further developing these.

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0017] The exemplary embodiments shown in FIGS. 1 and 2 show a separator 1 with a rotatably mounted drum 2, which has a technical drum volume as a predetermined reference volume.

[0018] This drum volume is determined by the dimensions of the internal volume 12 of the drum 2, as well as the dimensions and number of the disks of the disk stack 3 and the distance between them, etc., from the superstructure arranged within the internal volume 12. Further, the technical drum volume size includes, inter alia, the configurations such as one or more supply regions 4, distribution regions 5, separation plates 6, pairing chambers 7, pairing disks 8, discharge regions 9, etc. The above list is by no means exhaustive. Depending on the configuration, the individual structures listed above may be omitted or replaced by other structures without changing the overall principle described below.

[0019] Also, the separator 1 has a product inlet 10 and a flushing medium inlet 11, which flow into a common inflow pipe 13, which in turn at least partially forms part of the inflow region 4 within the internal volume 12 of the drum 2.

[0020] Furthermore, the separator 1 has a first outlet 14 for the light liquid phase, a second outlet 15 for the heavy liquid phase, and a solid outlet 16 as part of the solid discharge system. The separator 1 is configured to be recognized as a three-phase separator. However, the following principle can also be applied to two-phase separators, for example, clarifying separators.

[0021] The separators 1 shown in FIGS. 1 and 2 each have pressure sensors 23 and 24 at the first and second outlets 14 and 15 of the liquid phases. These pressure sensors 23 and 24 typically enable process monitoring during the separation of the light and heavy phases, such as the purification of water in oil. However, within the scope of the present invention, it is also possible to determine the reference volume and leakage by the above-mentioned sensors.

[0022] In addition, the separator 1 also has a control water inlet 22 provided, for example, by the hydraulic actuation of a piston slide as part of the solid discharge system, to control, for example, the release or discharge of solids. The water inlet 28 of the separator 1 branches into the two aforementioned water inlets 11 and 22. However, as already mentioned, the inlets 11 and 22 can also lead separately to the separator. Therefore, there is no limitation to the above-described configuration.

[0023] The supply of the amount of the flushing medium to the first flushing medium inlet 11 is controlled by the valve device 29 in FIG. 2, specifically by the valve 18. These can preferably be solenoid valves. Of course, the two valves 17 and 18 can also be combined with many port valves, and as a result, the valve device 29 can also include only one valve.

[0024] The amount and / or volume of the flushing medium supplied through the flushing medium inlet 11 is determined by the corresponding measuring device 19, preferably a flow meter. In particular, this can be arranged at the flushing medium inlet 11. The second outlet 15 for the heavy phase preferably also has a valve 20 which is preferably a solenoid valve.

[0025] The measured values determined by the measuring device 19, as well as the measured values of the pressure sensors 23 or 24, are transmitted to the control and / or evaluation unit 21 to control the valves 17 and 18 for the control and the flushing medium, and the valve 20 for the heavy phase. The purpose of measuring the flow rate of the flushing medium and the related valve control is to determine an adjusted reference volume.

[0026] The determined reference volume can be compared with the initial reference volume specified by the manufacturer or the actual free volume (for example, calculated from the geometric shape or determined by testing). The volume of an empty drum (the technical drum capacity depends on the type of machine (such as the size of the drum, the number and spacing of the disks, etc.) and is stored in the machine control system. The degree of dirt on the drum can also be determined from the comparison. Several steps as shown in FIG. 3 are required for the determination of leakage.

[0027] The first step (101) provides a separator with an empty drum and closed inlet and outlet. Depending on the configuration, an initial value of the reference volume or reference pressure of the separator becomes available when the drum is filled for the first time.

[0028] During the test run, the volume of the drum can be measured for the first time. For this purpose, after reaching the nominal speed, the drum is filled in step 102 until a defined pressure increase is detected by one of the pressure transmitters for each phase. The volume is stored in the drum as an adjusted reference volume. In particular, a flushing medium can be used for filling. The drum is filled by opening valve 18 until gripper 8 is immersed in water and the pressure at pressure sensor 24 increases. In this way, the filling volume of the liquid for filling the drum volume is determined by measuring device 19, preferably a flow meter, in particular an EMF.

[0029] The determined drum capacity can be saved as an adjusted reference value. If this newly determined reference value exceeds a limit level, for example 20% of the previously stored reference value, i.e., if the drum is overfilled by 20%, the pressure increase should generally be observed at pressure sensor 24 at one of the outlets of the phase. Otherwise, a drum leak message is issued.

[0030] Next, the centrifuge separator can be operated continuously, for example, to process the product. In continuous operation, the drum can be emptied completely or partially again in a third step 103 after a predetermined time interval, and the measurement can be performed again by introducing a flushing medium, similar to step 102. The inflow volume is determined by flow meter 19 and the reference volume can be adjusted again. The pressure sensor detects the pressure increase.

[0031] Finally, in a fourth step (104), the supply volume is compared as a reference value with the current measured value by flow meter 19. If there is no pressure increase after reaching the adjusted reference value of the drum capacity, a message 105 regarding leakage is issued.

[0032] When the pressure rises, for example, valve 18 can be opened again after 5 minutes, and it is checked whether the pressure rise is immediately detected by pressure sensor 24. If not, a warning "Check the drum seal" can be issued.

[0033] Therefore, measurements can be made at regular intervals even during the operation of the separator. For this purpose, either a full discharge operation or some partial discharge operations are carried out. Next, the pressure measurement can be started as described above.

Explanation of symbols

[0034] List of Symbols 1 Separator 2 Drum 3 Disk stack 4 Inlet region 5 Distribution region 6 Separation plate 7 Gripper chamber (light phase) 8 Gripper chamber (heavy phase) 9 Discharge region 10 Product inlet 11 First flushing medium inlet 12 Internal volume 13 Inlet pipe 14 First outlet (light phase) 15 Second outlet (heavy phase) 16 Solid outlet 17 Valve 18 Valve 19 Measuring device 20 Valve 21 Control and / or evaluation unit 22 Control water inlet 23 Pressure sensor 24 Pressure sensor 25 Bypass pipe 26 Solid collection region 27 Separator hood 28 Water inlet 29 Valve device 101 First process (trial operation) 102 Second process (first determination of reference volume) 103 Third process (repetition during operation) 104 Fourth process (comparison and output) 105 Message

Claims

1. A method for monitoring leakage of a drum of a centrifugal separator (1), comprising: A. Providing a centrifugal separator (1) containing an emptied drum and providing a reference volume value for the drum (2); B. A step of measuring the inflow volume by a measuring device (19) until the inflow volume reaches at least the reference volume of the drum (2); measuring the pressure by a pressure sensor (24) at the outlet of the C phase; D. evaluating the time sequence of pressure measurements after reaching the reference volume to determine a pressure rise; E. A method comprising outputting a signal when a determined increase in pressure occurs outside a predetermined time after the reference volume is reached.

2. The provision of the reference volume value of the drum (2) is preferably performed during the commissioning of the separator, I. Providing a centrifugal separator (1) with a predetermined reference volume according to its geometric dimensions; II. The method according to claim 1, characterized in that the step of filling the drum (2) and determining the volume of liquid required to fill the drum (2) corresponds to the currently available free drum volume of the drum (2) until a critical level is reached.

3. 3. The method according to claim 2, wherein the limit level indicating the maximum filling of the drum (2) is detected by measurement by one or more pressure sensors (23, 24) and / or by limit level switches at the outlets of the phases.

4. 4. The method according to claim 1, wherein a pressure sensor (23, 24) and / or a limit level switch is arranged at the heavy liquid phase outlet (15) of the separator (1).

5. 4. The method according to claim 1, wherein the liquid introduced to fill the drum is a flushing medium, and the flushing medium inlet (11) of the separator (1) for filling the drum (2) and the product inlet (10) of the separator (1) open into a common inlet pipe (13).

6. 4. A method according to any one of claims 1 to 3, wherein the volume required to fill the drum (2) is determined by a flow meter (19).

7. 7. The method according to claim 6, wherein the flow meter (19) is arranged in or at the product inlet (10) and / or particularly preferably in or at the flushing medium inlet (11) of the separator.

8. 4. The method according to claim 1, wherein the signal initiates an output at an output unit, preferably an alarm, and / or performs an immediate action on the operation of the separator, in particular initiating draining and / or shutting down of the separator.

9. 4. The method according to claim 1, wherein steps A to E are repeated at least twice, and in step B the drum is partially or completely emptied and then partially or completely filled.

10. 4. The method according to any one of claims 1 to 3, wherein at least steps B to E, and preferably the entire method, are carried out while the separator is rotating.

11. 4. The method of claim 1, wherein the degree of leakage is determined and output by evaluating the pressure rise and volume delivered within a time interval.

12. 4. The method according to claim 1, wherein the entire method is carried out without dismantling the separator, in particular the drum.

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