Method for monitoring drum leaks of centrifugal separator

Abstract

The invention relates to a method for monitoring drum leaks of a centrifugal separator (1), characterized in that it comprises the following steps: A) providing a centrifugal separator (1) comprising an emptied drum and providing a value for a reference volume of the drum (2); b) measuring the inflowing volume by means of a measuring instrument (19) until a reference volume of the drum (2) is reached; the method comprises the following steps: A) measuring the pressure in the outlet of a phase by means of a pressure sensor (24), D) evaluating a time sequence of measured values of the pressure after the reference volume has been reached in order to ascertain a pressure rise, and E) outputting a signal as long as the ascertained pressure rise occurs outside a time interval after the reference volume has been reached.

Description

Technical Field

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

[0002] During operation of a disc centrifuge, it is advantageous to detect leaks, in particular in the region of the so-called main bowl seal.

[0003] It is desirable to at least regularly check the drum interior for leakage, thereby ensuring the process technology function of the separator and improving operational safety overall. Summary of the invention

[0004] Starting from the above-mentioned problem, the object of the present invention is to provide a method for monitoring the leakage of a drum, in particular during operation and, if necessary, quantifying the degree of leakage.

[0005] The invention achieves this object by a method having the features of claim 1 .

[0006] The method according to the invention for monitoring leakage of a centrifugal separator drum comprises the following steps:

[0007] A. providing a centrifugal separator including an emptied drum, and providing a value for a reference volume of the drum;

[0008] The provision can be realized either during the commissioning of the separator or during the continuous operation of the separator by first emptying the drum and then refilling and measuring the pressure and the inflow volume in the product outlet of the drum. In the case of commissioning, the provision of the reference volume can be a predefined structural value, which is given by the manufacturer for the structural type of the separator. Step A is followed by step B.

[0009] B. technically detecting the inflowing volume by means of a measuring instrument, at least until the reference volume of the drum is reached;

[0010] In step B, the drum is filled. The volume flowing in, in particular the flushing medium, is detected until a reference volume is reached. However, the measurement detection also takes place after the reference volume has been reached, wherein the pressure increase is now also detected and evaluated by the sensor.

[0011] A flushing medium in the sense of the present invention can be any liquid which does not contain solid material, for example displacement water or a product phase.

[0012] If the pressure increase does not occur exactly when the reference volume is reached, the inflow volume determined can be recorded at the time of recording the measured value of the pressure increase. From this inflow volume, a new reference volume for filling the drum can be determined and stored.

[0013] If, for example, a further pressure rise occurs until a constant excess pressure is established at the outlet while the inflow remains constant, this indicates that the drum is leaktight. If, when the reference volume is reached, no pressure rise is detected at the product outlet of the outflowing phase, or if a pressure rise is determined after the time at which the reference volume is reached is detected, volume flows out of the drum at another point. In other words, if, despite reaching the reference volume, a pressure rise is observed only later, the drum is leaktight.

[0014] C. Technically detect the pressure at the outlet of one phase by means of a pressure sensor

[0015] D. After reaching the reference volume, analyze the time series of the pressure measurements to obtain the pressure rise

[0016] and

[0017] E. A signal is output as long as the ascertained pressure increase occurs outside a time interval after the reference volume has been reached.

[0018] As can be seen from the above description, each step can be implemented simultaneously with the corresponding subsequent step, or directly transition to the subsequent step.

[0019] Advantageous embodiments of the method are the subject of the dependent claims. Preferably, during commissioning of the separator, the value for the reference volume of the drum is provided by the following steps:

[0020] I. providing a centrifugal separator with a predefined reference volume depending on its geometric dimensions;

[0021] II. Filling the drum and determining the liquid volume required for filling the drum, which corresponds to the currently existing free drum volume of the drum until the limit is reached.

[0022] The limit position can be determined, for example, by means of a pressure sensor or a limit switch. The corresponding switches are known from process technology and measurement technology. They can be, for example, vibration switches or capacitive switches. However, a pressure sensor is preferred because it can also be used to determine the free drum volume, in particular as a reference volume for adaptation, or can also be used to quantify the extent of leakage.

[0023] The pressure sensor and / or the limit switch can be arranged in particular at the outlet of the heavier liquid phase or the clarified phase of the separator.

[0024] The liquid introduced for filling the drum is preferably a flushing medium, wherein the flushing medium inlet of the separator for filling the drum and the product inlet of the separator open into a common inflow pipe.

[0025] The determination of the volume required to fill the drum can advantageously be achieved by means of a flow meter. For electrically conductive media, such as water, a magnetically inductive flow meter is particularly preferably provided.

[0026] The flow meter can be arranged in or at the product inlet and / or particularly preferably in or at the flushing medium inlet of the separator.

[0027] If a signal is generated according to step E, it generates an output, preferably an alarm, at the output unit. Alternatively or additionally, direct action can be taken on the operation of the separator, in particular emptying and / or shutting down the separator, in order to prevent further product losses due to leakage and to protect the drum from wear.

[0028] Steps AE can be repeated at least twice, in particular at regular intervals, wherein in step B the drum can be filled after it has been emptied.

[0029] At least steps BE and preferably the entire method should be carried out while the drum is rotating.

[0030] Another advantage of this method is that the measurement can be carried out online during the process without disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Other advantages, features and details of the present invention are derived from the following description, in which embodiments of the present invention are explained in more detail with the aid of the drawings. A person skilled in the art may also consider the features disclosed in combination in the drawings, the description and the claims as appropriate and combine them into other meaningful combinations. In particular, there are many possibilities for changing and improving these within the scope of the present invention. The figure shows:

[0032] Figure 1 shows a perspective view of a separator according to the present invention;

[0033] Figure 2 shows a sectional view of a separator according to the invention for carrying out the method according to the invention; and

[0034] Figure 3 A schematic diagram of the method flow according to the present invention is shown. DETAILED DESCRIPTION

[0035] exist Figure 1 and 2 The exemplary embodiment shown in shows a separator 1 with a rotatably mounted drum 2 which has a technical drum volume as a predefined reference volume.

[0036] The drum volume is determined by the size of the inner volume 12 of the drum 2 and the superstructures arranged in the inner volume 12 (such as the size and number of the disks of the disk group 3 and their spacing from each other). In addition, the design of one or more inflow areas 4, distribution areas 5, separation disks 6, stripping chambers 7, stripping disks 8, outlet areas 9, etc. is included in the size of the technical drum volume. The above list is by no means final. Therefore, according to the design determined by the structural type, the various superstructures listed above can also be eliminated or replaced by other structures without changing the overall principle described below.

[0037] Furthermore, the separator 1 has a product inlet 10 and a flushing medium inlet 11 , which open into a common inlet pipe 13 , which for its part at least partially forms a part of the inlet region 4 in the inner volume 12 of the drum 2 .

[0038] 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 material discharge 16 as part of a solid material discharge system. It can be seen that the separator 1 is designed as a three-phase separator.

[0039] However, the following principles can also be applied to two-phase separators, such as clarifier separators.

[0040] exist Figure 1 and 2 The separator 1 shown in has pressure sensors 23 and 24 at the first and second outlets 14 and 15 of the liquid phase, respectively. These pressure sensors 23 and 24 generally enable process monitoring during the separation of light and heavy phases, for example the purification of water present in oil.

[0041] However, within the scope of the invention, it is also possible to determine the reference volume and the leakage with the aid of the above-mentioned sensors.

[0042] In addition, the separator 1 has a control water inlet 22, which is provided for controlling the solid material discharge or solid material emptying, for example by hydraulically actuated linear displacement of a piston slide valve as part of a solid material emptying system. Here, the water inlet 28 of the separator 1 branches into the two water inlets 11 and 22. However, as already mentioned, the inlets 11 and 22 can also be led to the separator separately. Therefore, there is no restriction to the described design.

[0043] Through the valve assembly 29 (in Figure 2 Specifically, the amount of flushing medium delivered to the first flushing medium inlet 11 is controlled by valve 18. Preferably, it can be a solenoid valve. Of course, the two valves 17 and 18 can also be combined in a multi-way valve, so that the valve assembly 29 can also include only one valve.

[0044] The amount and / or the volume of rinsing medium delivered via the rinsing medium inlet 11 is ascertained via a corresponding measuring device 19 , preferably a flow meter. The measuring device can be arranged in particular in the rinsing medium inlet 11 .

[0045] The second outlet 15 for the heavy phase preferably also has a valve 20 , preferably a solenoid valve.

[0046] The measured values ​​ascertained by the measuring device 19 and the measured values ​​of the pressure sensors 23 and 24 can be transmitted to a control and / or evaluation unit 21 which then controls the valves 17 and 18 for the control and flushing medium and the valve 20 for re-phasing.

[0047] The purpose of the flushing medium flow measurement and the associated valve control is to determine an adapted reference volume.

[0048] The determined reference volume can be compared with an initial reference volume predetermined by the manufacturer or with the actual free volume (e.g. calculated from geometry or determined in tests). The free drum volume (technical drum volume) depends on the machine type (drum size, number and spacing of the plates, etc.) and is stored in the machine control. From this comparison, the degree of contamination of the drum can then be additionally determined.

[0049] Identifying a leak requires multiple steps, such as Figure 3 shown.

[0050] The first step 101 is to provide the separator with an empty drum and closed inlet and outlet. Depending on the design, initial values ​​for the reference volume or reference pressure are available to the separator when the drum is first filled.

[0051] During commissioning, the volume of the drum can be detected for the first time by measuring technology. For this purpose, after reaching the rated speed, the drum is filled in step 102 until a defined pressure rise is detected at the pressure transmitter in one of the corresponding phases. This volume is stored in the drum as an adapted reference volume. For filling, a flushing medium can be used in particular. The drum is filled by opening the valve 18 until the gripper 8 is immersed in water and the pressure of the pressure sensor 24 increases. In this way, the filling volume of the liquid used to fill the drum volume is determined by means of the measuring device 19, preferably a flow meter, in particular an MID.

[0052] The determined drum volume can be stored as an adapted reference value. If this newly determined reference value exceeds a limit, for example 20% of the previously stored reference value, that is, if the drum is overfilled by 20%, a pressure rise at the outlet of one of the phases should usually be observed in the pressure sensor 24. Otherwise, a drum leak message is output.

[0053] Then, a continuous operation of the centrifuge can be carried out, for example for processing a product. In the continuous operation, the drum can be completely or partially emptied again after a predefined time interval in a third step 103, and a measurement can be carried out again by introducing a flushing medium, similar to step 102. The inflowing volume is determined by the flow meter 19. The reference volume can be adapted again. The pressure sensor detects the pressure rise.

[0054] Finally, in a fourth step 104, the inflow volume is compared as a reference value with the current measurement by the flow sensor 19. If no pressure rise occurs after reaching the adapted reference value for the drum volume, a message 105 about a leakage is output.

[0055] If, for example, the pressure is not yet displayed when a reference volume, for example 20% filling, is exceeded, an error should be displayed directly.

[0056] If the pressure rises, the valve 18 can be reopened, for example after 5 minutes, and a check can be made as to whether a pressure rise is immediately detected at the pressure sensor 24. If this is not the case, the alarm "Check drum seal" can be output.

[0057] Thus, measurements can also be carried out at regular intervals during the operation of the separator. For this purpose, either a complete emptying or a plurality of partial emptyings are carried out. The pressure measurement can then be started as described above.

[0058] Reference numerals list

[0059] 1 separator

[0060] 2 Rotating Drum

[0061] 3-disc set

[0062] 4Entrance area

[0063] 5. Allocation Area

[0064] 6 separation disc

[0065] 7 Light phase gripper room

[0066] 8-phase gripper room

[0067] 9 Export Area

[0068] 10Product entrance

[0069] 11 First flushing medium inlet

[0070] 12 Internal volume

[0071] 13 Inflow pipe

[0072] 14First exit (light phase)

[0073] 15 Second exit (heavy phase)

[0074] 16 Solid material discharge port

[0075] 17 valves

[0076] 18 valves

[0077] 19 Measuring instrument

[0078] 20 valves

[0079] 21 Control and / or analysis unit

[0080] 22 Control water inlet

[0081] 23. Pressure sensor

[0082] 24 Pressure Sensors

[0083] 25 bypass pipe

[0084] 26 Solid material collection area

[0085] 27 separator cover

[0086] 28 Water Inlet

[0087] 29 valve assembly

[0088] 101 Step 1 (Debugging and Running)

[0089] 102 Second step (obtaining reference volume for the first time)

[0090] 103 Third step (repeat during operation)

[0091] 104 Step 4 (Comparison and Output)

[0092] 105 News

Claims

1. A method for monitoring leakage of a centrifugal separator drum (1), characterized in that: The method comprises the following steps: A. providing a centrifugal separator (1) comprising an emptied drum, and providing a value for a reference volume of the drum (2); B. measuring the inflow volume by means of a measuring instrument (19) until the reference volume of the drum (2) is reached; C. Technically detecting the pressure at the outlet of one phase by means of a pressure sensor (24); D. After reaching the reference volume, the time series of the measured pressure values ​​is analyzed to determine the pressure rise, and E. A signal is output as long as the ascertained pressure increase occurs outside a time interval after the reference volume has been reached.

2. The method according to claim 1, characterized in that Preferably, during commissioning of the separator, the value for the reference volume of the drum (2) is provided by the following steps: I. Providing a centrifugal separator (1) with a predefined reference volume depending on its geometric dimensions; II. Filling the drum ( 2 ) and determining the liquid volume required for filling the drum ( 2 ), which corresponds to the currently existing free drum volume of the drum ( 2 ), until the limit is reached.

3. The method according to claim 2, characterized in that A limit level indicating the maximum filling of the drum (2) is detected by measurement technology in the outlet of a phase by means of one or more pressure sensors (23, 24) and / or by means of limit switches.

4. The method according to any one of the preceding claims, characterized in that Pressure sensors ( 23 , 24 ) and / or limit switches are arranged at the outlet ( 15 ) of the heavier liquid phase of the separator ( 1 ).

5. The method according to any one of the preceding claims, characterized in that The liquid introduced for filling the drum is a flushing medium, wherein a flushing medium inlet (11) of the separator (1) for filling the drum (2) and a product inlet (10) of the separator (1) open into a common inflow pipe (13).

6. The method according to any one of the preceding claims, characterized in that The volume required for filling the drum ( 2 ) is determined by means of a flow meter ( 19 ).

7. The method according to any one of the preceding claims, characterized in that 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. The method according to any one of the preceding claims, characterized in that The signal initiates an output at the output unit, preferably an alarm, and / or the signal initiates a direct action on the operation of the separator, in particular initiates an emptying and / or a shutdown of the separator.

9. The method according to any one of the preceding claims, characterized in that Steps AE are repeated at least twice, wherein in step B a partial or complete filling can be carried out after a partial or complete emptying of the drum.

10. The method according to any of the preceding claims, characterized in that At least steps BE, preferably the entire method, are carried out while the separator is rotating.

11. The method according to any one of the preceding claims, characterized in that By evaluating the pressure increase and the volume introduced within a time interval, the extent of the leakage is determined and output.

12. The method according to any one of the preceding claims, characterized in that The entire method is carried out without disassembling the separator, in particular without disassembling the drum.

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