PUMPING SYSTEM

Abstract

A pumping system includes a pumping chamber with a fluid sensor that has a cylindrical shaft extending into the priming chamber. The sensor has a sensing dome at one end of the cylindrical shaft extending into the priming chamber, the dome having a vertical base with a diameter smaller than the diameter of the cylindrical shaft. The sensor indicates to a controller whether fluid is present based on an algorithm with settings for electromagnetic field damping, electric field conductance, and / or magnetic field permittivity, using configurations that correlate with the fluid environment. The controller controls the operation of the pump and priming system based on the sensor signal.

Description

PUMPING SYSTEM RESEARCH OR DEVELOPMENT SPONSORED BY THE FEDERAL GOVERNMENT

[0001] Not applicable. MICROFICHE / COPYRIGHT REFERENCE

[0002] Not applicable. FIELD OF INVENTION

[0003] The present invention relates to pumps and, in particular, to vacuum-primed pumps. BACKGROUND OF THE INVENTION

[0004] Pumps for liquids or fluids, which often contain non-microscopic solid particles, are well known in the art and normally use rotary or centrifugal action to mechanically propel the fluid in the desired direction.

[0005] Typically, these pumps are vacuum-primed and positioned above the level of the liquid being pumped. In such installations, the pump will not operate correctly unless there is a fluid head from the lower liquid level onto the pump itself. See, for example, U.S. Patent No. 7,331,769, which describes a vacuum-primed pumping system. That is, if the fluid does not reach the pump, the pump will simply draw in air and will not create sufficient force to draw the fluid into the pump for the desired pumping. Therefore, such pumps are primed with fluid to ensure that there is the required fluid head extending into the pump so that it can operate as intended.Furthermore, it is important that the pump impeller, mechanical seal, or packing be fully submerged to prevent air from entering the pump and potentially blocking the impeller, thus preventing the pump from operating. This is typically achieved by using a separate vacuum pump, connected to the main pump at its highest point, to ensure that all air is removed as required.

[0006] Until now, in applications where the fluid includes debris, sensors have been used to detect the presence of fluid at the level required to ensure that the pump is in a primed state, as shown in U.S. Patents Nos. 3,519,369 and 5,035,583. However, those sensors have extended into the priming chamber enough to come into contact with a significant amount of debris, and the sensors have been such that the debris could envelop or cover the priming sensor, causing false priming detections.

[0007] In addition, when such pumps are used in applications where they will encounter different and changing conditions (e.g., where the fluid includes debris and / or different components, such as water and oils), false priming detections may also occur when the conditions in which they are used change.

[0008] The present invention is directed to overcome one or more of the problems set forth above. SUMMARY OF THE INVENTION

[0009] In one aspect of the present description, a pumping system includes a main pump for pumping fluid from an inlet to an outlet, a priming chamber disposed above the pumping chamber, and a primer for drawing fluid into the priming chamber to at least a selected depth at which the main pump will operate properly. A sensor has a cylindrical shaft extending into the priming chamber with a detection dome at one end of the cylindrical shaft at the selected depth. The detection dome is shaped like a spherical cap with a vertical base at one end of the cylindrical shaft. The vertical base has a smaller diameter than the diameter of the cylindrical shaft. The detection dome is adapted to detect the presence of liquid at the selected depth in the priming chamber and to indicate whether liquid is present at that depth.A controller is adapted to control the operation of the pump and the priming system depending on whether the signal indicates the presence of fluid at the selected depth.

[0010] In one form of the pumping system, the sensor is adapted to adjust the sensor sensitivity in correlation with the fluid characteristics in the priming chamber.

[0011] In another form of the pumping system, the sensor includes an algorithm adapted to detect the presence of liquid in environments that have various forms of debris in the liquid, including threads and rags. The algorithm has settings for variables that include at least one of electromagnetic field damping, electric field conductance, and magnetic field permittivity.

[0012] In another form of the pumping system, the sensor periodically signals to the controller whether liquid is present at the selected depth, and the controller switches the operation of the pump between the main and non-main states when the sensor signal indicates a change of state during a selected period.

[0013] In another form of the pumping system, the controller is adapted to control the operation of the pump and the primer by (a) activating the primer when the sensor signal indicates that no liquid is present at the selected depth, and (b) allowing the main pump to be operated when the sensor signal correlates with a fluid depth in the priming chamber that is at least the selected fluid depth for fluid that has characteristics that correlate with the fluid in the priming chamber. In another form, one of the fluid characteristics is the presence or absence of oil in the water.

[0014] In another form of the pumping system, the controller allows the pump to operate when the sensor signal indicates the presence of liquid at the selected depth for a selected period of time.

[0015] In another aspect of the invention, a pumping system includes a main pump for pumping fluid from an inlet to an outlet with a priming chamber disposed above the pumping chamber. A primer introduces fluid into the priming chamber to at least a selected depth at which the main pump will operate properly. The pumping system also includes a controller and a domed sensor supported in the priming chamber at the selected depth. The sensor is adapted to detect a liquid-air interface at the selected depth in the priming chamber and send the detected interface to a controller.The controller is adapted to (a) correlate the depth of the selected fluid in the priming chamber with the selected interfaces detected by the sensor based on the characteristics of the fluid in the priming chamber, and (b) control the operation of the pump and primer based on whether the selected sensor detected the interface sent by the sensor correlates with the depth of the selected fluid in the priming chamber for the fluid that has characteristics that correlate with the fluid in the priming chamber.

[0016] In another form of this pumping system, the controlled operation of the pump and priming system comprises (a) activating the priming system when the detected interface sent by the sensor correlates with a fluid depth in the priming chamber that is less than the fluid depth selected for fluid that has characteristics that correlate with the fluid in the priming chamber, and (b) allowing the main pump to operate when the detected interface sent by the sensor correlates with a fluid depth in the priming chamber that is at least the fluid depth selected for fluid that has characteristics that correlate with the fluid in the priming chamber.

[0017] In another form of this pumping system, the fluid characteristics may include at least one of the presence or absence of greases, oils or lubricants (FOG) or a large amount of solid debris in the fluid.

[0018] In yet another form of this pumping system, the controller enables the pump to operate when the sensor sends the detected interface between the liquid and the air to the controller for a selected period of time.

[0019] In yet another form of this pumping system, the sensor has a cylindrical shaft extending into the priming chamber with a detection dome at one end of the cylindrical shaft, the detection dome being in the form of a spherical cap with a vertical base at one end of the cylindrical shaft, the vertical base of the cap having a smaller diameter than the diameter of the cylindrical shaft.

[0020] Other objects, features and advantages of the invention will become apparent from a review of the complete descriptive memorandum, including the claims and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a cross-sectional view of a pump incorporating the advantageous priming operation;

[0022] Figure 2 is a cross-sectional view of a pump suction chamber according to the prior art;

[0023] Figure 3 is a cross-sectional view of a pump suction chamber according to Figure 1;

[0024] Figure 4 is a circuit diagram for detecting fluid in the pump suction chamber according to Figure 1;

[0025] Figure 5 is a circuit diagram for controlling the operation of the pump based on the detection of fluid in the pumping station chamber using the sensor and incorporating an optional communication module to monitor the sensor and allow modification of the sensor settings;

[0026] Figure 6 is a flow diagram showing the fluid detection by sensor in the pump suction chamber; and

[0027] Figure 7 is a flow diagram showing the pump sensor monitoring to determine when maintenance is required. N C N N DETAILED DESCRIPTION OF THE PREFERRED OPTION

[0028] Figure 1 shows a pumping system 10 according to the present invention. The system 10 includes a main pump 14 and can be used to pump fluid from a level below the main pump 14 into a pump inlet 16 and then out through a pump outlet 20.

[0029] The main pump 14, particularly illustrated in Fig. 1, includes a suitable casing, such as a volute 24, having an impeller 26 rotatably driven in a pumping chamber 30 by a suitable motor 34. A suitable seal 36 is provided around the pump's impeller shaft 40, sealing the motor 34 from the volute 24. It should be understood, however, that the present invention can be used with a wide variety of primed pumps, and that the details of the main pump 14 illustrated in the figures are merely examples of such a pump with which the invention can be advantageously used.

[0030] A suction or priming chamber 50, which may be part of the adapter for the pump motor 34 and the volute 24, is defined above the volute 24 and is used to draw priming fluid into the pump inlet 16 as described below. A throttling opening 54 is provided between the suction chamber 50 and the pumping chamber 30.

[0031] A transparent plastic-cased dome 60 may be provided over the suction chamber 50 to allow visual inspection inside the dome 60. A suitable vacuum line 64 is connected to the dome 60 to generate a vacuum in the suction chamber 50 as appropriate. Specifically, a vacuum pump 66 may be connected to the vacuum line 64 and selectively operated to prime the main pump 14. It should be appreciated that any vacuum pump 66 capable of generating a sufficient vacuum to prime the main pump 14 will be suitable.

[0032] United States Patent No. 7,331,769 B2 entitled Pumping System and issued on February 19, 2008 describes a pumping system similar to that shown in Fig. 1 in this document, and the full description of that patent is incorporated herein by reference.

[0033] In prior art systems, a sensor 70A, as illustrated in Fig. 2, extended through an opening into the suction chamber 50 and included an end-sensing element 72A that detects the fluid level in the suction chamber 50. Specifically, the sensing element 72A is secured at a height where it will contact the fluid in the suction chamber 50 when the fluid is at a level to prime the main pump 14, i.e., is high enough for the fluid level to be sufficient for the main pump 14 to operate properly. However, as noted above, in applications where the fluid includes debris, sensors 70A, such as those illustrated in Fig.2, which include forks with an air gap in the middle, will not only come into contact with a significant amount of debris, but this debris will also envelop or coat the 72A sensor element, causing false priming detections.

[0034] Figure 3 illustrates a different sensor 80 that can be advantageously used with pumping systems 10 such as those described herein. The sensor 80 has a generally cylindrical shaft 82 extending into the priming chamber 50 with a sensing dome 86 at the end of the cylindrical shaft 82 at the fluid height required for the pump 14 to operate properly. The sensing dome 86 is shaped like a spherical cap or segmented dome with a vertically oriented base 88 at the end of the cylindrical shaft 82. The vertical base 88 of the cap has a smaller diameter than the diameter of the cylindrical shaft 82. ic Lrnn / zznz / E / YiAi

[0035] Furthermore, the sensor 80 can advantageously be a capacitive sensor having a generally horizontal face to detect the relative motion of the interface between the fluid and the air in the priming chamber of the pump 50. The sensing dome 86 generates an electric field in the priming chamber 50, measuring the dielectric properties of the medium in the pump chamber to detect only liquid or fluid. As described in more detail in this document, once fluid is detected, the sensor changes state to ON, indicating that the pump is primed and therefore ready for operation.

[0036] The Sensor 80 incorporates a new primary detection technology for wastewater environments containing debris such as rags, thread, wipes, or other disposable waste that can create maintenance problems for other types of sensors. It has custom configurations to provide better system response than standard sensors. The Sensor 80 evaluates the media on the probe face using multiple measurement points. The measurements are controlled by sensitivity settings on the Sensor 80 to optimize sensor performance and determine if liquid is present on the Sensor 80 face. An algorithm integrated into the Sensor 80 evaluates the measurements and provides signals to indicate when liquid is present on the probe.

[0037] By providing said sensor 80 as described, there is a reduced surface area and a reduced projection in the priming chamber 50 relative to previously used sensors (such as sensor 70A in Fig. 2) to prevent debris in the fluid from enveloping or covering sensor 80. This reduces false priming and further limits the frequency of maintenance required to clean previous sensors such as the 70A.

[0038] The Sensor 80 incorporates a new sensing technology to create effective pump priming in this application and in a wastewater environment containing debris such as rags, thread, wipes, or other disposable waste that can create maintenance problems for other types of sensors. Advantageously, the Sensor 80 has customizable settings, including reaction time, to provide better system response for wastewater applications. The Sensor 80 also advantageously incorporates high-frequency spectrum scanning (to evaluate the media on the probe face using multiple measurement points), electromagnetic field damping, electric field conductance, and magnetic field permittivity.These measurements can be advantageously controlled by custom sensitivity settings on the sensor 80 to optimize the sensor's performance for this application and determine if liquid is present on the sensor 80 face. An algorithm can be advantageously incorporated into the sensor 80 to evaluate the measurements and provide signals to indicate when liquid is present on the probe.

[0039] Sensor 80 can be used advantageously to detect the presence of fluid as described in this document.

[0040] The pumping system 10 described herein also provides advantageous operation in conjunction with sensor 80.

[0041] Specifically, as illustrated in Fig. 4, the sensor 80 can be provided with a suitable power supply 100 to operate as desired (and as described later in this document). A circuit breaker 102 is provided to allow the power to be cut off when necessary, such as during maintenance. The sensor 80 is connected by wiring to a relay 104 that changes state depending on whether the sensor 80 indicates that the main pump 14 ic Lrnn / zznz / E / YiAi is primed or not.

[0042] Furthermore, as illustrated in Figs. 1 and 5, the sensor 80 can be part of a system 110 in which a programmable logic controller (PLC) 120 and a communication module 130 cooperate with the sensor 80 to facilitate control of the pump system 10 as illustrated in Figs. 6 and 7.

[0043] A 130 communication module that can be used advantageously with the 110 system as described herein is a 10 Link Master.

[0044] The basic operation of pumping system 10 is as follows.

[0045] If the fluid level is lower than desired in pump 14 for pump operation, the vacuum pump 66 will operate to generate a vacuum in the vacuum line 64 and in turn will generate a vacuum in the suction chamber 50.

[0046] Once the fluid level has reached a sufficient depth for pump 14 to be considered primed, the fluid will come into contact with the dome 86 of sensor 80 and, as described in more detail below, sensor 80 will indicate that pump 14 is primed and vacuum pump 66 can be switched off.

[0047] Until now, the use of 70A sensors in pumping applications such as those described herein has relied on fixed configurations for the 70A sensor, regardless of the initial and / or changing conditions of the specific installation. The 110 system described herein, on the other hand, allows for fine-tuning of the liquid sensing settings for challenging wastewater installations, as well as adjustment over time based on changing conditions. Furthermore, the 110 system described herein provides sensor feedback to enable monitoring for facilitating maintenance and / or adjustment of the sensor when appropriate. That is, as described herein, the 130 communication module, the 120 controller, and the associated logic provide diagnostics that allow the 80 sensor configurations to be properly adjusted and controlled.The control logic and sensor 80 allow the operator to adjust the main sensing control settings for sensor switching and time setpoints via an operator interface screen.

[0048] Figure 6 shows a flowchart that illustrates the adjustable priming detection control logic.

[0049] When initially configured (step 200), the settings for sensor 80 establish the sensitivity of sensor 80 to indicate when liquid is present (step 202) and when liquid is not present (step 204), as well as the time period during which such an ON / OFF state (liquid present / not present) must exist (step 206) to recognize that the detected state has changed from liquid present (or not present) to liquid not present (or present). These settings (steps 202, 204, 206) can be factory-configured on the sensor itself, but if they are adjusted for particular installation conditions, they can be adjusted at the factory or adjusted in the field (using, for example, a PC, PC software, and a cable connected to the sensor) with such settings saved on sensor 80.

[0050] During operation, if the ON setting of the sensor's liquid sensitivity switch (0-100%) (step 210) is met, then an internal time delay is initiated in sensor 80. The ON setting of the liquid sensitivity switch is reached when the percentage read by sensor 80 is greater than or equal to the setpoint (set in step 202). If this time delay setting is met (for example, in 0.1-second increments) and the ON setting of the sensor is still met (step 212), then sensor 80 indicates that pump 14 is primed (step 214).

[0051] Subsequently, if sensor 80 has been indicating priming (step 214), and the sensor detects that the current liquid sensitivity ic Lrnn / zznz / E / YiAi is less than the OFF setting (0-100%) (step 216), then sensor 80 no longer indicates priming (step 218), i.e., it recognizes that the main pump 14 is not primed and will remain in that detected condition until the ON setting of the sensor's liquid sensitivity switch (0-100%) (step 210) is met for a sufficient period of time (step 212), at which point it will switch to indicating priming again (step 214).

[0052] It should be noted that if the sensor settings are too sensitive and therefore cause false priming indications, an operator would soon recognize this and adjust the settings (e.g., using a connected PC, software, and cable) (steps 202, 206) to make them less sensitive. Examples of sensor settings that are too sensitive might include the ON setpoint being too low (step 202), the OFF setpoint being too high (step 204), or the transition time setpoint being too low (step 206). Conversely, if the sensor setting is not sensitive enough, the sensor might not indicate that the pump is primed, even though it is.Examples of sensor settings that are not sensitive enough could include setting the ON setpoint too high (step 202), or setting the transition time setpoint too high (step 206). Additionally, if the switch OFF setpoint is set too low, then sensor 80 may not reset from a primed state (steps 214, 216), also causing a false prime detection.

[0053] In addition to the sensor 80 adjustability described above, the system 110 which also includes the PLC 120 and communication module 130 provides diagnostics that monitor the sensor's performance to alert (via a connected human-machine interface [HMI]) when preventive maintenance is required (e.g., alerting an operator that the sensor is dirty and may need maintenance).

[0054] Figure 7 illustrates the steps for monitoring and providing diagnostics (step 300) also through the HMI connected to the communication module 130. That is, as illustrated in Figure 5, the priming sensor 80 is connected to a suitable communication module 130 connected to the PLC 120 and communicates multiple sensor parameters to the HMI, such as the device status (step 302), the transition time setpoint (step 304), the liquid sensitivity ON and OFF switch setpoints (steps 306, 308), and the current temperature (steps 310, ic Lenn / zznz / E / YiAi 312) An operator can adjust various sensor settings, such as the ON and OFF setpoints of the liquid sensitivity switch and the transition time setpoints, via the HMI. These settings are then stored in sensor 80, with the most recent settings used to indicate the pump's primary status. Furthermore, since the status of sensor 80 (step 320) can be advantageously monitored by an operator via the HMI, the operator can easily determine if maintenance is required. If sensor 80 is in good condition (i.e., functioning correctly), the desired continuous operation of pump 14 can be permitted (step 322). However, if sensor 80 is not in good condition, the operator will recognize this via the HMI and provide the necessary information, including sensor maintenance and / or adjustment of the various settings to reflect the actual conditions encountered by pump 14.

[0055] The PLC 130 and the associated sensor diagnostic monitoring logic enable trend generation, sensor status monitoring, and the issuance of preventive maintenance messages. It also allows for adjusting sensor settings to improve performance in a given environment. For example, in an environment with a wastewater stream, ic Lenn / zznz / E / YiAi, water with a high oil content may be encountered, requiring the sensor 80 liquid sensitivity settings to be adjusted to less sensitive values ​​to indicate that the main pump 14 is primed. Conversely, when clean water is encountered, the liquid sensitivity settings will need to be adjusted to more sensitive values ​​to indicate that the pump is primed.Additionally, if the main sensor device status monitor indicates that sensor 80 is not in a functional state, then an operator can be informed via the HMI that sensor adjustment or maintenance is required.

[0056] Furthermore, because the temperature and liquid sensitivity exhibit trends, this allows for advantageous monitoring of the sensor's health. The PLC 130 monitors whether the sensor 80 is operating at acceptable levels (becoming dirty or coated, or if the application involves water with a high oil content) and requires adjustment or maintenance. That is, when a particular time trend monitor setting is established (step 304), the PLC 130 can advantageously monitor one or more liquid sensitivity deltas (step 308), temperature (step 310), and temperature delta (step 312) over that period. If, during that time, any of the monitored variables falls outside the established range, the PLC 130 will recognize that maintenance is required and will notify the operator via the HMI.Similar maintenance indications may be provided if (a) the liquid sensitivity setting and liquid sensitivity delta setting are enabled and the current sensor liquid reading is not within the set range, and / or (b) the temperature setting and temperature delta setting are enabled and the current sensor temperature reading is not within the set range.

[0057] In addition, an operator can select which trend values ​​are necessary for monitoring the sensor's status and, via the HMI, enable or disable them as needed. For example, if temperature and temperature delta are not required, the user can disable them so that these variables are still transmitted through the HMI but will not be used to determine the sensor's status and / or indicate whether sensor maintenance is required. Alternatively, the same can be done with liquid sensitivity settings, if necessary.

[0058] Further aspects, objects, and advantages of the present invention can still be obtained from a study of the specification, drawings, and accompanying claims. ic Lrnn / zznz / E / YiAi It should be understood, however, that the present invention could be used in alternative forms in which fewer of all the objects and advantages of the present invention and the preferred embodiment described above would be obtained.

Claims

1. A pumping system, comprising: a main pump for pumping fluid from an inlet to an outlet, said main pump including a pumping chamber adapted to receive fluid from said inlet; a priming chamber disposed above said pumping chamber; a primer for drawing fluid into said priming chamber to at least a selected depth at which said main pump will function properly;a sensor having a cylindrical shaft extending into said priming chamber with a detection dome at one end of the cylindrical shaft at said selected depth, said detection dome being in the form of a spherical cap with a vertical base at one end of the cylindrical shaft, said vertical base cap having a diameter smaller than the diameter of the cylindrical shaft, said sensor being adapted to detect the presence of liquid at said selected depth in the priming chamber and to signal whether liquid is present at said selected depth; and a controller adapted to control the operation of said pump and priming device depending on whether said signal indicates the presence of fluid at said selected depth.

2. The pumping system according to claim 1, wherein said sensor is adapted to adjust the sensitivity of said sensor in correlation with the characteristics of said fluid in said priming chamber.

3. The pumping system according to claim 1, wherein said sensor includes an algorithm adapted to detect the presence of liquid in environments that have various forms of debris in the liquid, including threads and rags, said algorithm having settings for variables that include at least one electromagnetic field damping, electric field conductance, and magnetic field permittivity.

4. The pumping system according to claim 1, wherein said sensor periodically signals to said controller whether liquid is present at said selected depth; said controller switches the operation of the pump between the main and non-main states when said sensor signal indicates a change of state during a selected period.

5. The pumping system according to claim 1, wherein said controller is adapted to control the operation of said pump and priming pump by: activating said priming pump when said sensor signal indicates that there is no liquid present at said selected depth, and allowing said main pump to operate when said sensor signal correlates with a fluid depth in said priming chamber that is at least the fluid depth selected for fluid having characteristics that correlate with said fluid in said priming chamber.

6. The pumping system according to claim 5, wherein one of said fluid characteristics is the presence or absence of oil in the water. ic Lrnn / zznz / E / YiAi 7. The pumping system according to claim 1, wherein said controller enables the operation of said pump when said sensor signal indicates the presence of liquid at the selected depth for a selected period of time.

8. A pumping system, comprising: a main pump for pumping fluid from an inlet to an outlet, said main pump including a pumping chamber adapted to receive fluid from said inlet; a priming chamber disposed above said pumping chamber; a primer for drawing fluid into said priming chamber to at least a selected depth at which said main pump will function properly; a controller; and a dome-shaped sensor supported in said priming chamber at said selected depth; wherein said sensor is adapted to detect a liquid-air interface at said selected depth in the priming chamber, and to send said detected interface to a controller;and said controller is adapted to correlate said selected fluid depth in said priming chamber with selected interfaces detected by sensors based on the characteristics of said fluid in said priming chamber, and to control the operation of said pump and primer based on whether said selected detected interface sent by said sensor correlates with said selected fluid depth in said priming chamber for fluid having characteristics that correlate with said fluid in said priming chamber.

9. The pumping system according to claim 8, wherein said controlled operation of said pump and primer comprises: 29 activating said primer when said detected interface sent by said sensor correlates with a fluid depth in said priming chamber that is less than the fluid depth selected for fluid having characteristics that correlate with said fluid in said priming chamber, and allowing said main pump to operate when said detected interface sent by said sensor correlates with a fluid depth in said priming chamber that is at least the fluid depth selected for fluid having characteristics that correlate with said fluid in said priming chamber.

10. The pumping system according to claim 9, wherein said fluid characteristics may include at least one of the presence or absence of greases, oils or lubricants (FOG) or a large amount of solid debris in the fluid.

11. The pumping system according to claim 8, wherein said controller enables the operation of said pump when said sensor sends said detected liquid-air interface to said controller for a selected period of time.

12. The pumping system according to claim 8, wherein said sensor has a cylindrical shaft extending within said priming chamber with a detection dome at one end of the cylindrical shaft, said detection dome being in the form of a spherical cap with a vertical base at one end of the cylindrical shaft, said vertical base cap having a diameter smaller than the diameter of the cylindrical shaft.

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