Process fluid maintenance in a manufacturing environment

Abstract

A system and method for maintaining process fluid including a sump for storing a process fluid and a machine tool connected to the sump, wherein the machine tool receives the process fluid from the sump. A feed line for supplying at least one of water and an additive concentrate to the sump is provided. The feed line includes a valve, wherein opening of the valve allows at least one of water and the additive concentrate to enter the sump. A concentration sensor is connected to the internal volume of the sump and is configured to measure a concentration of the additive concentrate in the process fluid. A temperature sensor is connected to the internal volume of the sump and is configured to measure a temperature of the process fluid adjacent to the concentration sensor. A measurement system is connected to the concentration sensor and the valve.

Description

PROCESS FLUID MAINTENANCE TN A MANUFACTURING ENVIRONMENTCROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. Provisional application number 63 / 693,424, filed September 11, 2024, the teachings of which are incorporated herein by reference.FIELD

[0002] The present disclosure relates to the maintenance of process fluids in a manufacturing environment, and in particular to the monitoring and adjustment of process fluids used in metal and ceramic machining processes.BACKGROUND

[0003] Cutting fluids are used in various metalworking and ceramic machining processes. The cutting fluid is supplied to a machine tool, which employs a tool for drilling, milling, turning, tapping, reaming, cutting, boring, grinding, shearing, or combinations thereof. Machine tools may include drill presses, gear shapers, hobbing machines, honing machines, lathes, screw machines, milling machines, shears, bandsaws, planers, grinding machines, and multitasking machines such as CNC machines. These cutting fluids provide various functions including cooling the machine tool and workpiece, provide lubricity between the machine tool and the workpiece, cleaning chips and other scrap away from a workpiece and machine tool, preventing corrosion to the workpiece and machine, and minimizing airborne particulate.

[0004] Depending on the application, the cutting fluids may include various additives, such as lubricants, salts, soap, surfactant, water soluble polymer, petroleum derived oils including synthetic oil and mineral oil, alcohol, glycol, water soluble polymers, antibacterial agents, antifungal agents, sugar, antifreeze, corrosion inhibitors, and combination thereof. The additives are provided in a concentrate and are often combined with water to provide the cutting fluid. Depending on the additives, the combination of the additive concentrate with the water may form an emulsions or dispersion or a solution.

[0005] Cutting fluid quality changes as the fluid is used in the manufacturing process and reclaimed for reuse. For example, some of the water or other additives may evaporate atprocess temperatures, increasing additive concentration. In addition, the polymers and oils may degrade due to working temperatures and shear. Further, hydraulic fluid, machine lubricants, and rust preventatives from the incoming parts may be captured in the reclaimed cutting fluid. These fluids are called tramp oil, which forms films on the machine tool, workpieces, and chips, potentially making them sticky and stick to the workpiece or machine tool. In addition, the film formed by the tramp oil interferes with sensors and cutting fluid performance. Further, the overall amount of cutting fluid in the system may be decreased by retention of the cutting fluid on the machine tool, workpiece, and chips when they are filtered out.

[0006] The quality, characteristics, and fluid levels or volumes are desirably monitored at regular intervals throughout a cutting or shaping process. Individual sensors have been used to measure various characteristics of the cutting fluid, including fluid concentration, temperature, level or volume of cutting fluid within the sump or storage tank, pH and conductivity. The data obtained by the sensors may be provided to a computer controller and the controller may be used to add more water, coolant concentrate, additive concentrate, individual additives or any combination thereof to bring the process back to optimal operating state. However, adding individual sensors for making specific, unique measurements increases system complexity. Alternatively, operators may record and trend sensor data. However, operators may make errors in recording the data or fail to record the data at desired intervals or fail to take correct action when data indicates an out of optimal process.

[0007] Thus, while the present systems and methods for maintaining cutting fluid in a manufacturing environment achieve their intended purpose, there is a need for new and improved systems and methods for maintaining cutting fluid in the manufacturing environment.SUMMARY

[0008] According to various aspects, the present disclosure relates to a system for maintaining process fluid in the manufacturing environment. The system includes a sump for storing a process fluid in an internal volume defined by the sump, and a machine tool connected to the sump, wherein the machine tool receives the process fluid from the sump. The system also includes a regenerative filter between the machine tool and the sump,wherein the process fluid passes through the regenerative filter upon being returned to the sump. The system further includes a feed line for supplying at least one of water and an additive concentrate to the sump, wherein the feed line includes a valve, wherein opening of the valve allows at least one of water and the additive concentrate to enter the sump. In addition the system includes a concentration sensor connected to the internal volume of the sump, wherein the concentration sensor is configured to measure a concentration of the additive concentrate in the process fluid, and a temperature sensor connected to the internal volume of the sump, wherein the temperature sensor is configured to measure a temperature of the process fluid adjacent to the concentration sensor. The system also includes a measurement system connected to the concentration sensor and the valve, wherein the measurement system is configured to determine a concentration of the additive concentrate in the process fluid, a level of the process fluid in the sump relative to the concentration sensor, a presence of tramp oil in the process fluid, and a regeneration of the regenerative filter. The measurement system is configured to open the valve to provide at least one of water and additive concentrate to the process fluid if at least one of the concentration of the additive concentrate in the process fluid is too high, a level of the process fluid in the sump relative to the concentration sensor is too low, and a temperature of the process fluid is too high.

[0009] In embodiments of the above, the measurement system is configured to open the valve when the additive concentrate concentration of the process fluid is determined to be zero indicating the level of the process fluid is lower than the concentration sensor.

[0010] According to any of the above embodiments, the measurement system is configured to open the valve when the concentration of the additive concentrate in the process fluid is higher than a desired range and to close the valve when the concentration of the additive concentrate is lower than the desire range.

[0011] According to any of the above embodiments, the measurement system is configured to open the valve when the measurement system detects an increase in temperature of the process fluid in the sump.

[0012] In further embodiments, the measurement system is configured to open the valve after at least one of 1) the increase in temperature occurs longer than a predeterminednumber of measurement cycles of increasing temperature, and 2) the increase in temperature occurs over a number of cycles that do not coincide with machine cycles.

[0013] According to any of the above embodiments, the measurement system is configured to open the valve after the temperature remains constant over an extended number of measurement cycles.

[0014] According to any of the above embodiments, the measurement system is configured to activate a tramp oil skimmer when the additive concentrate concentration is measured at 100 percent.

[0015] According to any of the above embodiments, when the additive concentrate concentration is measured at 100 percent for more than a minimum number of measurement cycles, the measurement system is configured to add repair chemistry to the sump.

[0016] According to any of the above embodiments, when the additive concentrate concentration remains constant over an extended number of data measurement cycles, the measurement system is configured to perform at least one of the following actions: add repair chemistry to the sump, circulate the process fluid in the sump, and provide a notification to a user to recycle the process fluid.

[0017] According to any of the above embodiments, the measurement system further includes a second concentration sensor connected to a mixer tank connected to the feed line.

[0018] According to various additional aspects, the present disclosure relates to a method for maintaining process fluid in a process fluid maintenance system. The method includes measuring a concentration of an additive concentrate in a process fluid in a sump using a concentration sensor, wherein the sump stores the process fluid in an internal volume defined by the sump. A machine tool is connected to the sump, wherein the machine tool receives the process fluid from the sump, and a regenerative filter is present between the machine tool and the sump, wherein the process fluid passes through the regenerative filter upon being returned to the sump. The method also includes measuring a temperature of the process fluid adjacent to the concentration sensor in the sump with a temperature sensor. The method further includes determining a concentration of the additive concentrate in the process fluid, a level of the process fluid in the sump relative to the concentration sensor,a presence of tramp oil in the process fluid, and a regeneration of the regenerative filter, with a measurement system connected to the concentration sensor and a valve wherein the measurement system is configured to determine a concentration of the additive concentrate in the process fluid, a level of the process fluid in the sump relative to the concentration sensor, a presence of tramp oil in the process fluid, and a regeneration of the regenerative filter. In addition, the method includes opening a valve with the measurement system to provide at least one of water and additive concentrate to the process fluid in the sump if at least one of the concentration of the additive concentrate in the process fluid is too high, a level of the process fluid in the sump relative to the concentration sensor is too low, and a temperature of the process fluid is too high, wherein opening of the valve allows at least one of water and the additive concentrate to enter the sump.

[0019] In embodiments of the above, the method includes opening the valve when the additive concentrate concentration of the process fluid is determined to be zero indicating the level of the process fluid is lower than the concentration sensor.

[0020] In any of the above embodiments, the method further includes opening the valve when the concentration of the additive concentrate in the process fluid is lower than a desired range and to close the valve when the concentration of the additive concentrate is higher than the desire range.

[0021] In any of the above embodiments, the method further includes opening the valve when the measurement system detects an increase in temperature of the process fluid in the sump. In further embodiment, the method includes opening the valve after at least one of 1) the increase in temperature occurs longer than a predetermined number of measurement cycles of increasing temperature, and 2) the increase in temperature occurs over a number of cycles that do not coincide with machine cycles.

[0022] In any of the above embodiments, the method further includes opening the valve after the temperature remains constant over an extended number of measurement cycles.

[0023] In any of the above embodiments, the method further includes activating a tramp oil skimmer when the additive concentrate concentration is measured atlOO percent.

[0024] In further embodiments, the method includes opening the valve when the additive concentrate concentration is measured atlOO percent for more than a minimum number of measurement cycles.

[0025] In any of the above embodiments, the method further includes opening the valve when the additive concentrate concentration remains constant over an extended number of data measurement cycles.

[0026] In any of the above embodiments, the method further includes determining if regeneration of a regenerative filter is occurring too often and isolating the process fluid from the machine tool from the sump by closing a machine tool valve.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

[0028] FIG. 1 illustrates an embodiments of a system for maintaining a process fluid in a manufacturing environment according to embodiments of the present disclosure.

[0029] FIG. 2 illustrates a method of maintaining a process fluid in a manufacturing environment according to embodiments of the present disclosure.

[0030] FIG. 3 illustrates a graph of an example of a data set representing process fluid concentration over multiple measurement cycles according to embodiments of the present disclosure.

[0031] FIG. 4 illustrates a graph of an example of a data set representing fdter regeneration frequency over multiple measurement cycles according to embodiments of the present disclosure.

[0032] FIG. 5 illustrates a graph of an example of a data set representing process fluid temperature over multiple measurement cycles according to embodiments of the present disclosure.

[0033] FIG. 6 illustrates a graph of an example of a data set representing process fluid concentration over multiple measurement cycles according to embodiments of the present disclosure.DETAILED DESCRIPTION

[0034] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding introduction, summary, orthe following detailed description. Tt should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0035] Reference will now be made in detail to several examples of the disclosure that are illustrated in accompanying drawings. Whenever possible, the same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale.

[0036] The present disclosure is directed to the maintenance of process fluids in a manufacturing environment, and in particular to the monitoring and adjustment of process fluids used in metal and ceramic machining processes. While the process fluids herein are described as being used in machining applications, and are often referred to as cutting fluids, the technology is not limited to cutting fluids used in machining applications but may also be applied to other applications as well. The concepts herein may be applied to applications where fluid systems are monitored for consistency and quality, including but not limited to screen printing and other painting or coating applications, thermal fluid systems including heat transfer fluid systems and refrigerant systems, mining fluids, food and beverage applications, oil and gas applications, life sciences, etc.

[0037] FIG. 1 illustrates a process fluid maintenance system 100. The system 100 includes a sump 110 for storing the process fluid 112. The process fluid 112, in this case a cutting fluid, includes two components, an additive concentrate, also called a coolant concentrate, and water. The additive concentrate includes one or more additives such as lubricants, salts, soap, surfactant, water soluble polymer, petroleum derived oils including synthetic oil and mineral oil, alcohol, glycol, water soluble polymers, antibacterial agents, antifungal agents, sugar, antifreeze, and corrosion inhibitors. The additive concentrate is combined with water at various ratios, depending on the process. Depending on the additives, the combination of the additive concentrate with the water may form an emulsion, dispersion, or a solution.

[0038] The process fluid 112 is pumped through one or more conveyance lines 114 by a conveyance pump 116 to one or more machine tools 118. In embodiments, not illustrated, the sump 110 is located within the machine tool 118 itself. Machine tools 118 include, but are not limited to, drilling machines such as drill presses, turning machines such as lathes, gear shapers, hobbing machines, taping machines, reaming machines, honing machines, screw machines, milling machines, shears, bandsaws, planers, grinding machines, andmultitasking machines such as CNC machines. The machine tools 118 shape workpieces formed from materials including metals such as aluminum, ferrous alloys, exotic alloys, super alloys, plastics, glass reinforced composites, carbon fiber, quartz, glass, and more. Wood, expanded foam, fiberglass, and other materials may be used in prototyping and also shaped with the machine tools.

[0039] In embodiments, the process fluid 112 is filtered through a regenerative filter 121, wherein chips, i.e., pieces of material removed from the work piece, and other debris or contaminants are removed from the process fluid 112 in a tank 120 (often referred to as a chip hopper) in the individual machine tools 118 and returned directly to the sump 110. In alternative embodiments, as illustrated, the process fluid 112 is additionally or alternatively conveyed to a drag out tank 122 through drain lines 124. In the drag out tank 122, chips and other solid debris are removed from the process fluid 112 by a conveyor. Additionally or alternatively, process fluid 112 is removed from the chips by a pucker in which the chips are compressed, or a cyclone where the chips are spun. The tanks 120 in the machine tools 118 and drag out tank 122 may include a regenerative filter 121 to remove the chips and other debris. The process fluid 112 is then pumped from the tanks 120 in the individual machine tools 118 or drag out tank 122 through recapture lines 128 via a pump 130 to the sump 110. Valves may be provided in the line between the tanks 120 in the machine tools 118, the drag out tank 122 if present, and the sump 110.

[0040] In embodiments, a tramp oil skimmer 134 is provided. The tramp oil skimmer 134 removes hydraulic fluid, rust inhibitors, refrigerants, and machine lubricants that have been captured in reclaimed process fluid 112. The tramp oil skimmer 134 may also remove free product oil, oil that has separated from the process fluid. The tramp oil skimmer intake 136 is inserted into the process fluid 112 present in the sump 110 and skimmed waste is removed from the sump 110. Alternatively or additionally, at least one of a coalescer or a cyclone separator may be used to remove tramp oil.

[0041] When the process fluid 112 is at a low level, that is a low fluid volume is present in the sump 110 or the concentration of the process fluid 112 needs to be adjusted, at least one of water and additive concentrate is added to the sump 110. In embodiments, water is provided from a water source 140. The water is preferably deionized to prevent the buildup of salts and other contaminants in the system. The water 140 is fed into a mixer tank 142,including a mixer, through a water feed line 144 and regulated by a water valve 146. Similarly, the additive concentrate is fed into the mixer tank 142 through an additive concentrate feed line 148 from an additive concentrate tank 150. The flow of the additive concentrate through the additive concentrate feed line 148 is regulated by a valve 152. The combined water and additive concentrate in the mixer tank 142 form a “pre-mix.” Once mixed, the combined water and additive concentrate pre-mix are fed into the sump 110 through a feed line, in this case a mixer line 154, connected to the mixer tank 142. It should be appreciated that multiple mixer tanks 142 may be present, each including pre-mix including different additive concentrate concentration levels.

[0042] In alternative or additional embodiments, the water and additive concentrate are added individually into the sump 110 through the mixer tank 142 and mixer line 154. Alternatively, the water and additive concentrate may be added individually through feed lines directly into the sump 110 bypassing the mixer tank 142. Additionally, the water and additive concentrate may be added automatically to the process fluid at predetermined time intervals, upon a signal / input provided by the system, or upon user request. In further embodiments, the user may add water and additive concentrate into the sump 110 with a manually activated device, such as a hose, from the mixer tank 142, at random time intervals.

[0043] Additionally, repair chemistry, or other additives, may be added to the sump 110 from a supply tank 194. The repair chemistry is fed through a feed line, in this case a repair chemistry line 196. In embodiments, a repair chemistry pump may be energized to transfer the repair chemistry into the sump 110, or a valve 198 may be provided in the feed line 196, which may be opened to supply the repair chemistry or other additive to the sump 110 or closed to stop the supply of the repair chemistry or other additive to the sump 110. The repair chemistry includes, in embodiments, at least one of an emulsifier and a pH modifier. The repair chemistry is provided as a concentrate. Alternatively, the repair chemistry may be provided diluted in water.

[0044] The process fluid 112 is monitored utilizing one or more concentration sensors 160. A concentration sensor 160 is mounted onto the sump 110 at a known height h from the top or bottom of the sump 110 and inserted into the internal volume V of the sump 110. Further, the concentration sensor 160 is mounted proximal to at least one of the feed lineoutlets such as mixer line 154, recapture line 128 and, the drain lines 124 outlet into the drag out tank 122. The concentration sensor 160, known as a refractometer, measures the refractive index, i.e., the extent to which light incident on the liquid is bent as it passes into, through the liquid, and out of the liquid. The refractive index provides concentration data of the process fluid 112 and is typically measured in Brix, which is understood as a measurement of dissolved solids in liquid. The Brix measurement is multiplied by a factor, typically ranging from 0.9 to 4.0, to provide a percentage that is representative of the amount of the additive concentrate in the process fluid. The refractive index varies from zero percent, such as in the situation where process fluid 112 is not present, to 100 percent, such as in the situation where the concentration sensor 160 is covered by, for example, tramp oil. Between 0 percent and 100 percent refraction indicates the concentration of the additive concentrate in the process fluid 112. In addition, the concentration sensor 160 also includes a temperature sensor such as a thermocouple, resistance thermometer, or thermistor. In alternative embodiments, the temperature sensor may be a separate sensor from the refractometer but is, in further embodiments, preferably mounted adjacent the concentration sensor 160. In additional or alternative embodiments, a concentration sensor 160 including a temperature sensor is also included in individual machine tool tanks 120, or in the centralized drag out tank 122 that collects process fluid from one or more machine tools 118 as well as in the mixer tank 142 or in a premix tank. In further embodiments, one or more concentration sensors 160 and temperature sensors are the only sensors operatively connected to the sump 110, and optionally the drag out tank 122, and configured to measure the process fluid 112. A concentration sensor 160 located in each machine tool 118 may be used to indicate that a machine tool has not been in operation in a while as it would exhibit a difference concentration of the additive concentrate than the sump 110 and would not exhibit cycling of the temperature of the process fluid 112. This information may then be used to trigger circulation of the process fluid in the machine tool 118.

[0045] Each concentration sensor 160 (or concentration and temperature sensors) provides data or information, in the form of voltage changes or other signals representing information regarding the concentration and temperature to a measurement system 164, which in embodiments is integrated into the concentration sensor 160 or external to the concentration sensor 160. Concentration and temperature data is repeatedly measured fromthe concentration sensor 160 and data points from the measurement cycles are stored in non-transitory memory 170 in a measurement system 164 or in non-transitory memory in the concentration sensor 160. In embodiments, the concentration sensor 160 may also provide conductivity measurements.

[0046] Recordation of individual data points from the measured data occurs at one or more time intervals, also referred to herein as measurement cycles or data measurement cycles, and in embodiments, individual data points are preferably stored in at least two time interval datasets, one interval being relatively shorter than the other. For example, in embodiments, data points are measured and stored at relatively short time intervals, or measurement cycles, in the range of 1 second to 30 seconds, including all values and ranges therein, such as 10 seconds, and the measured data points taken at relatively longer time intervals, or measurement cycles, of every 5 minutes to every 30 minutes, including all values and ranges therein such as every 10 minutes, are also stored as a second data set in the non-transitory memory. That is, while only one dataset is measured, multiple data sets are created by recording the measured data at different intervals. In additional or alternative embodiments, measurements are taken and data is recorded when a measurement value changes or a measurement value changes by a predetermined amount, rather being recorded than at given intervals. For example, a measurement may be taken and recordation of the measurements may be triggered by the measurement system 164 determining that a significant event has occurred, such as additive concentrate concentration levels being detected as being low or high, i.e., outside of an upper or lower limit. The different measurement recording intervals may provide different information regarding the quality, characteristics, and level of the process fluid 112 in the sump 110. While the sensors primarily measure concentration and temperature, concentration measurements are also used to indicate additional quality, characteristic, and fluid level information regarding the process fluid 112 as described further below.

[0047] In embodiments, the concentration and temperature data from the concentration sensor 160 is communicated over an electrical wire 166 connected to both the concentration sensor 160 and the measurement system 164. In alternative embodiments, the concentration and temperature data is wirelessly communicated from a sensor communication system 162 at the concentration sensor 160 to the measurement system 164. In embodiments wherethe measurement system 164 is located within the process facility, the sensor communication system 162 may use one or more communication protocols including, but not limited to, wired local area networks, IO-Link industrial communication networking standard IEC 61131-9, IEEE 802.11 LAN standards (Wi-Fi), Cellular, Bluetooth Special Interest Group standards, Wireless USB, NearLink, and Zigbee. Alternatively, the measurement system 164 may be located remotely from the process facility and use, for example, fiber-optics, coaxial cable, digital subscriber lines (DSL), and cellular data communication as described further below.

[0048] The measurement system 164 includes a controller 168 and non-transitory memory 170 as well as a first communication system 174 for receiving information from sensor communication system 162 in the concentration sensor 160. Further, the measurement system 164 is connected to one or more relays which control various electrical circuits that control the valves 146, 152, 158, 198 for delivering water, additive concentrate, pre-mix, repair chemistry, and other additives to the mixing tank 142 or the sump 110, as well as to valves (not illustrated) that connect the individual machine tools 118 to the sump 110 or drag out tank 120, turn on and off the tramp oil skimmer 134, and turn on and off the repair chemistry pump. In embodiments, the measurement system 164 displays information on a local human interface device 172, which includes at least one of: 1) one or more LED lights, 2) a display screen that displays information regarding the process fluid 112 to a user, such as concentration and fluid level, and 3) notification sounds. In addition, the human interface device may also include inputs, such as keyboards, pointing devices, touch screens, magnetic strip readers, etc., used to provide feedback and control the process fluid maintenance system 100.

[0049] In addition, or alternatively, the first communication system 174 is also configured to wirelessly communicate information from the measurement system 164 to a remote system 180. The remote system 180 may include an external diagnostic visualizer 182 in the form of a personal device, such as a smart phone, laptop, remote desktop, etc., wherein the remote system 180 includes an application including software configured to display the readings of the concentration sensor 160 and other outputs from the measurement system 164. The external diagnostic visualizer 182 further includes an external display 184 connected to an external visual processing module 186. The external display 184 is visuallyaccessible to users remote from the facility where the sump 110 and other equipment is located or to users within the facility, and even users looking directly at the sump 110 and other equipment. The external display 184 includes a graphic user interface 188 that the user may interact with using, for example, a touch screen integrated into the graphic user interface 188 or an electro-mechanical interface connected to external diagnostic visualizer 182. The external communication system 182 also includes a wireless communication system 192 for communicating with the first communication system 174. In addition to displays, the external communication system 182 may provide audible alerts through speakers. It should be appreciated that alerts may also be provided by text messages, emails and other forms of communication that may be received and displayed by the external communication system 182.

[0050] The process fluid maintenance system 100, including the measurement system 164 and the controller 168 therein, is configured to execute instructions for maintaining process fluid 112 in a manufacturing environment, including maintaining desired concentration ranges of the additive concentrate in the process fluid, desired levels, i.e., fluid volume, of the process fluid in a sump 110, and controlling the operation of the tramp oil skimmer 134. The instructions may include one or more separate programs, each of which comprises an ordered listing of executable instructions for implementing logical functions. The instructions, when executed by the measurement system 164, receive and process signals from the concentration and temperature sensor(s) 160, perform logic, calculations, methods and / or algorithms for executing process control instructions and depending on the measurements detected by the measurement system 164, alter the indicators emitted by at least one of the human interface device 172 and the external diagnostic visualizer 182, and, in embodiments, provide information to the human interface device regarding the present state of the system. Examples of data collected are illustrated in the graphs of FIGS. 3 through 6. Further, in embodiments, the measurement system 164 triggers at least one of the following: opening one or both valves 146, 152 used to add water and additive concentrate into the process fluid 112 in the sump 110 or into the mixer tank 142, opening the valve 158 between the mixer tank 142 and the sump 110, opening the repair chemistry valve 198, energizing the repair chemistry pump, and activating the tramp oil skimmer 134. Alternatively, or additionally, the valves 146, 152, 158, 198, tramp oil skimmer 134, andrepair chemistry pump may be triggered manually by a user, having received an alert from a human interface device associated with the measurement system 164 or the external communication system 182. The instructions carry out the method for maintaining process control fluid in a manufacturing environment as described further herein.

[0051] FIG. 2, with reference to FIG. 1, illustrates a method 200 for maintaining process fluid in a manufacturing environment, which may be executed by measurement system 164 in the process fluid maintenance system 100 and the controller 168 in the measurement system 164. At block 202, a process fluid 112 such as a cutting fluid is circulated from a sump 110, through a machine tool 118, optionally through individual machine tool tanks 120, optionally through a drag out tank 122, and back into the sump 110 as described above. At block 204 the measurement system 164 receives a first set of concentration data and temperature data of the process fluid 112 measured repeatedly at a first time interval from a concentration sensor 160 positioned in a known location in the sump 110 and records this data. In further embodiments, the measurement system 164 records a second set of concentration data and temperature data from the concentration sensor 160 of the process fluid 112 repeatedly at a second time interval. Alternatively, the second set of data is selected from the first set of data. The concentration data primarily represents the concentration of the additive concentrate in the process fluid 112. In embodiments where the concentration sensor 160 is located in the sump 110, the concentration data is also indicative of the process fluid 112 level in the sump 110 relative to the concentration sensor 160, and the presence of tramp oil in the sump 110 as described further herein. In further embodiments a concentration sensor 160 may be located in the drag out tank 122, the concentration data is indicative of the process fluid 112 level in the drag out tank 122 relative to the concentration sensor 160, and the presence of tramp oil or product oil in the drag out tank 122 as described further herein. In further embodiments, a concentration sensor 160 is located in the mixer tank 142 and may be used to determine the concentration of the additive concentrate in the pre-mix, infer if the additive concentrate tank 150 is empty, or if there is a blockage or leak in either the water feed line 144 or the additive concentrate feed line 148.

[0052] At block 206 the concentration of the additive concentrate in the process fluid 122 is determined after each recorded measurement by the measurement system 164 using, forexample, the factor described above for converting Brix measurements to percentages. Further, at block 208 the rate of change in the concentration of the additive concentrate in the process fluid is determined based on changes in the concentration data over time. At block 210 data regarding the machine tool and location of the concentration sensor 160 is determined or referenced. It should be appreciated that machine tool and location data may be referenced at any time during the method 200 prior to this point as well, such as before blocks 202, 204, or 206. It is noted that the information regarding the location of the concentration sensor 160 in the sump 110 includes the height of the concentration sensor 160 from the bottom of the sump 110, the location of the concentration sensor 160 relative to the tramp oil skimmer 134, and the location of the concentration sensor 160 relative to the outlet 156 of the mixer line 154. Information regarding the location of a concentration sensor 160 that may be present in the drag out tank 122 also includes the height of the concentration sensor 120 from the bottom of the drag out tank 122, the location of the concentration sensor 160 relative to the outlet of the drain lines 124, and the location of the concentration sensor 160 relative to the filter 121, and the inlet of the feed line 128. Information regarding the machine tool includes whether the machine tool includes a tank 120 for reclaiming process fluid 112 or if the process fluid 112 is conveyed to a drag out tank 122 before the process fluid 112 is returned to the sump 110, whether the sump 110 is being filled by user or by measurement system 164, and the type of filtering performed in the machine tool 118.

[0053] At block 212 at least one of the concentration of the additive concentrate in the process fluid 112, the rate of change in the concentration of the additive concentrate in the process fluid 112, the location of the concentration sensor 160, the temperature data, and the information regarding the machine tool 118, is used to identify at least one of the following conditions: the process fluid 112 level, i.e., volume, in the sump 110 relative to the concentration sensor 160, the amount of additive concentrate in the process fluid 112, i.e., whether the amount of additive concentrate is too high or too low relative to a desired range, the quality of the process fluid present in the sump 110 and whether there is too much tramp oil or product oil in the process fluid or foaming of the process fluid, and whether a process fluid fdter cleaning cycle has occurred. For example, if the process fluid 112 level in the sump 110 falls below the concentration sensor 160, the concentrationsensor 160 may register either zero concentration or 100 percent concentration of the additive concentrate. Where the concentration sensor 160 registers zero concentration for a minimum number of measurement cycles selected to rule out, e.g., fluctuations in the process fluid 112 level in the sump 110 due to disturbances caused by circulating the process fluid from the machine tools 118 or due to the addition of process fluid, at least one of pre-mix, water, and additive concentrate may be added to the sump 110 from the mixer tank 142 at block 214 until the concentration sensor 160 measures a concentration above zero percent. In cases where 100 percent concentration of the additive concentrate is registered for more than a minimum number of measurement cycles, it may be inferred that there an abundance of tramp oil or free product oil in the process fluid and at least one of the following actions should be taken: activating the tramp oil skimmer 134 and adding repair chemistry to the sump 110 by opening the repair chemistry valve 198 or energizing the repair chemistry pump. On the other hand, in cases where 100 percent concentration of the additive concentrate is registered for less than the minimum number of measurement cycles, then the measuring system may perform at least one of the following actions: activating the tramp oil skimmer 134, adding repair chemistry, and provide a notification to a user to recycle the process fluid (i.e., remove the used process fluid and add new process fluid), however additional pre-mix is not needed.

[0054] Additional conditions may be identified as well. For example, if the concentration sensor 160 is near the premix injection point, that is, the concentration sensor 160 is near the outlet 156 of the mixer line 154, a determination can be made regarding how long premix was added into the fluid based on at least one of 1) fluctuations in the temperature of the process fluid measured by the temperature sensor and 2) the rate of fluctuations in the concentration of the additive concentrate in the process fluid as the addition of premix will cause a relatively rapid drop or increase in the concentration level of the additive concentrate. Tracking the additions of premix at a known additive concentrate concentration can be used to determine when the additive concentrate tank 150 will be empty.

[0055] FIG. 3 illustrates a representative data set illustrating changes in the concentration of the additive concentrate in the sump 110 in the process fluid maintenance system 100 as the process fluid 112 is circulated through the system 100. The horizontal, x-axis illustratesthe number of data measurement cycles and the vertical, y-axis illustrates the concentration as measured in Brix. As the process fluid 112 is circulated through the process fluid maintenance system 100 the concentration of the additive concentrate increases over a relatively high number of cycles due to evaporation of water. Upon additions of pre-mix, the concentration measured by the concentration sensor 160 drops abruptly. Additional premix may be added when a maximum concentration level is reached and added until the concentration reaches a minimum concentration level where addition of the premix is ended. In addition, when the process fluid level, fluid volume, is determined to be low because the concentration measured by the concentration sensor is zero, water or premix may be added through one or more feed lines until the concentration of the process fluid registers again. Once the concentration of the process fluid is measured above zero percent, or if the additive concentrate concentration is measured and determined to be too low additive concentrate may be added to the sump 110. If additive concentrate concentration is detected as being too high, water may be added to the sump 110.

[0056] If the concentration sensor 160 is on a “clean tank” of a regenerative filter 121 found either in the machine tool 118 or the sump 110, a determination can be made as to the type of regeneration of the regenerative filter 121, such as regeneration through blowing air on the filter element in the regenerative filter, and regeneration by cleaning or changing the filter in the regenerative filer 121. The frequency of the regeneration of the regenerative filter 121 may also be determined. FIG. 4 illustrates a representative data set illustrating filter regeneration frequency. The horizontal, x-axis illustrates the number of data measurement cycles and the vertical, y-axis illustrates the Brix concentration. As illustrated in the graph, the data illustrated in the graph drops to zero upon filter regeneration. This is due to the fluid volume decreasing along with the level of the fluid in the sump 110 and can be determined given the location of the concentration sensor 160. In the illustrated process, filter regeneration generally occurs approximately every 750 cycles. It is expected these are filter blow downs. The range of actual number of data cycles filter generation may be expected to occur varies based on the material the workpieces are formed from, the expected size of the chips cut from the work piece, and the expected volume of chips. Between 49000 and 49500 measurement cycles, the data drops to zero twice in a relatively short period of time indicating that the second drop included changing the filter media. Iffilter regeneration occurs too often or the filter media is changed too often, that is, filter regeneration occurs repeatedly after a lower than expected number of cycles, then a machine tool 118 may need to be isolated from the drag out tank 122, or shut down altogether, or an extra filtrate aid, such as cellulose, needs to be added to the drag out tank 122.

[0057] As noted above, installing concentration sensors 160 in the mixer tank 142 allows prediction of the concentration of the process fluid 112 in the sump 110 after addition of the “pre-mix” in the mixer tank 142 to the sump 110. In addition, monitoring the mixing tank 142 and the pre-mix allows predictions of whether the additive concentrate tank 150 is empty or predictions of whether sufficient water is available from the water source 140. This information may then be used to display an alert.

[0058] Information regarding the temperature of the process fluid 112 provides information on machine tool 118 steady state, operating times of the machine tools 118, machining cycles of the machine tools 118, disruptions or system shocks to the machine tools 118 and other components of the system 100, etc. FIG. 5 illustrates a graph of temperature fluctuations. The horizontal, x-axis illustrates the data measurement cycle and the vertical, y-axis illustrates the change in temperature of the process fluid. Each machine cycle, i.e., period over which the machine tool 118 performs an operation, corresponds with an increase and decrease in temperature. Low sump volume may be identified with elevated temperature, which may cause foaming and reduce tool life, reduce surface finish, and potentially even result in catastrophic failures such as the welding of a tool in a machine tool 118 to a work piece being shaped. Thus, upon measuring an increasingly elevated temperature after a predetermined number of cycles or a number of cycles that do not coincide with the machine cycles, additional premix may be added to the sump 110 to reduce the temperature of the process fluid 112. Further, if temperature remains constant over an extended number of measurement cycles, occurring over days to a few weeks or longer, additional premix may be added to refresh the antimicrobial properties of the process fluid 112.

[0059] FIG. 6 illustrates a graph of concentration spikes over a number of cycles. The horizontal, x-axis illustrates the data measurement cycle and the vertical, y-axis illustrates the concentration. If the concentration remains relatively consistent for an extended periodof measurement cycles, in the illustrated graph, over 20,000 cycles from 20,000 cycles to approximately 45,000 cycles, then at least one of the following actions may be taken: repair chemistry may be added to refresh the various components of the additive concentrate that may deteriorate over time; circulating the process fluid in the sump, and providing the user a notification to recycle the process fluid. While, in the present illustration, the extended period ranged about 25,000 cycles, an extended period may be any given period that may cause a reduction in properties of the additive concentrate, such as the antimicrobial properties.

[0060] Further, in embodiments, at block 212, information is displayed on the human interface device 172, such as green, orange / yellow, and red LED lights or information on a display screen. Additionally or alternatively, information is displayed on an external communication system 182 to indicate the system status. Sound alerts, texts messages, emails, or other notifications may be provided to the user either at the local human interface device 172 or external communication system 182 if, for example, at least one of: 1) process fluid 112 volume, 2) the additive concentrate concentration levels, and 3) tramp oil levels exceed predetermined upper and lower limits. And, in embodiments, information on aspects of the system to check and review may be displayed, including for example, checking if foam is developing, whether there is a break or leak anywhere in the system 100, etc.

[0061] Optionally, at block 214, at least one of the amount of water in the sump 110 and the amount of additive concentrate in the sump 110 may be adjusted, premix may be added to the sump 110, repair chemistry may be added to the sump 110, the tramp oil skimmer 134 may be activated, the process fluid 112 may be circulated in the sump 110 or through the system 100, and process fluid from a machine tool 118 may be isolated and blocked from entering the sump 110 by the measurement system 164. In addition, various notifications may be provided to a user to perform one of the following actions: circulate process fluid, manually add at least one of water, additive concentrate, and repair chemistry, and recycle the process fluid and add new process fluid. For example, if it is detected the additive concentrate or water should be added to the sump 110, at least one of the valves 146, 152, 158 associated with the water supply 140, additive concentrate tank 150, and mixer tank 142 may be opened by the measurement system 164. As previously noted, theamount of water and additive concentrate may additionally or alternatively be adjusted manually by the user or directly by the measurement system 164. Similarly, if present, the tramp oil skimmer 134 may be activated by the measurement system 164, due to, for example, changes in concentration or temperature of the process fluid 112 indicating when the machine tools 118 are running. Additionally or alternatively, the tramp oil skimmer 134 may be manually activated by a user.

[0062] Expanding on the above, if the measurement system 164 identifies that the process fluid 112 volume in the sump 110 is too low because the concentration sensor 160 no longer detects fluid present at the sensor level (such as when the concentration sensor 160 detects zero refraction for an extended number of time intervals (i.e., measurement cycles), such as in the range of 30 minutes to an hour) at block 212, then at least one of additional water, additive concentrate, and premix, is added to the sump 110 to raise the level of the process fluid 112 at block 214. If zero refraction is detected by the concentration sensor 160 for a number of time intervals (i.e., measurement cycles) that the machine tool 118 takes to run a fdter regeneration cycle and then, after the number of time intervals the concentration sensor 160 detects refraction greater than zero percent at block 212, additional water and additive concentrate is not necessary to replenish the sump 110 at block 214, unless the concentration measured by the concentration sensor 160 indicates the additive concentrate concentration is too low or too high. To correct the concentration of the additive concentrate, additive concentrate may be added directly to the sump 110 if the concentrate levels are too low and water may be added directly to the sump 110 if the concentrate levels are too high.

[0063] If the measurement system 164 identifies that the additive concentrate concentration is too low or too high in the process fluid 112 after a selected number of time intervals at block 212, additional additive concentrate or additional water may be added to the sump 110 at block 214 by opening the at least one of the mixer valve 158 associated with the mixer tank 142, the water valve 146 associated with the water source 140, and the additive concentrate valve 152 associated with the additive concentrate tank 150, are opened until the concentration meets the desired level. If after an extended number of time intervals the additive concentrate concentration continues to decrease at block 212, then the additive concentrate tank 150 is checked to determine if it is empty, the additiveconcentrate feed line 148 is checked to determine if there is a break in the additive concentrate feed line 148, the mixer tank 142 is checked to determine if it has failed, and the additive concentrate is replenished at block 214. Similarly, if after an extended number of time intervals the additive concentrate concentration continues to increase at block 212, then the water source 140 and water feed line 144 are checked to determine if there is an interruption in the water supply and the mixer tank 142 is checked to determine if it has failed, and the water is replenished at block 214. If the concentration sensor 160 detects and the measurement system 164 identifies that the additive concentrate concentration is too low or too high in the process fluid 112, or fluctuates for a given number of time intervals, and the concentration sensor 160 is positioned near the outlet 156 of the mixer line 154 at block 212, a selected number of time internals is allowed to pass and the concentration data is checked again at block 212 to determine if the change in concentration is due to the addition of additive concentrate or water to the sump 110 or due to the concentration of the additive concentrate being too high or too low. If it is the latter, then the amount of water or additive concentrate are adjusted at block 214.

[0064] If the concentration sensor 160 detects 100 percent refraction for an extended period of time, such as greater than a half hour, then the tramp oil skimmer 134 is checked or activated by the measurement system to remove tramp oil from the process fluid 112 in the sump 110 and the process fluid 112 is checked for quality issues, such as separation of the components in the process fluid.

[0065] Further, based on the temperature of the process fluid 112 at block 212, it may be determined how much the machine tool 118 is running, which increases the temperature of the process fluid 112. In addition, the temperature of the process fluid 112 may further increase if the amount of process fluid 112 in the system (including the sump 110, the feed lines 114, 124, 128, and the machine tool 118) is dropping too low at block 212 and the process fluid 112 may be replenished at block 214 by activating the related valves to add at least one of water, additive concentrate, premix, and repair chemistry.

[0066] The system and method includes a number of advantages, these advantages include the measurement and prediction of the issues noted above as well as the prediction of untested conditions, such as machining hours, fluid addition frequency, fluid addition amount, regeneration of the regenerative fdter, regenerative filter regeneration type, fluidhealth by tramp oil (foreign oil or product separation), etc. Additional advantages include the notification of users when the process fluid is out of tolerance, or when there may be interruptions in the machining process.

[0067] As used herein, the term "controller" and related terms such as microcontroller, control module, module, control, control unit, processor and similar terms refer to one or various combinations of Application Specific Integrated Circuit(s) (ASIC), Field- Programmable Gate Array (FPGA), electronic circuit(s), central processing unit(s), e.g., microprocessor s) and associated non-transitory memory component (s) in the form of memory and storage devices (read only, programmable read only, random access, hard drive, etc.). The controller 168 may also consist of multiple controllers which are in electrical communication with each other.

[0068] A processor may be a custom made or commercially available processor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processor among several processors associated with the controller 168, a semi composite conductor-based microprocessor (in the form of a microchip or chip set), a macro processor, a combination thereof, or generally a device for executing instructions.

[0069] The tangible, non-transitory memory 170 may include volatile and nonvolatile storage in read-only memory (ROM), random-access memory (RAM), and keep-alive memory (KAM), for example. KAM is a persistent or non-volatile memory that may be used to store various operating variables while the processor is powered down. The tangible, non-transitory memory 126 may be implemented using a number of memory devices such as PROMs (programmable read-only memory), EPROMs (electrically PROM), EEPROMs (electrically erasable PROM), flash memory, or another electric, magnetic, optical, or combination memory devices capable of storing data, some of which represent executable instructions, used by the controller 168.

[0070] Communication systems, including the sensor communication system 162, the first communication system 174, the external communication system 182, are wireless communication systems configured to communicate via a wireless local area network (WLAN) using IEEE 802.11 standards or by using cellular data communication. However, additional or alternate communication methods, such as a dedicated short-range communications (DSRC) channel, are also considered within the scope of the presentdisclosure. DSRC channels refer to one-way or two-way short-range to medium-range wireless communication channels specifically designed for industrial use and a corresponding set of protocols and standards. Accordingly, a communication system may include one or more antennas and / or transceivers for receiving and / or transmitting signals, such as cooperative sensing messages (CSMs).

[0071] The description of the present disclosure is merely exemplary in nature and variations that do not depart from the gist of the present disclosure are intended to be within the scope of the present disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure.

Claims

AMENDED CLAIMS received by the International Bureau on 09 January 2026 (09.01.2026)CLAIMSWhat is claimed is:

1. A system for maintaining process fluid in the manufacturing environment, comprising: a sump for storing a process fluid in an internal volume defined by the sump; a machine tool connected to the sump, wherein the machine tool receives the process fluid from the sump; a regenerative filter between the machine tool and the sump, wherein the process fluid passes through the regenerative filter upon being returned to the sump; a feed line for supplying at least one of water and an additive concentrate to the sump, wherein the feed line includes a valve, wherein opening of the valve allows at least one of water and the additive concentrate to enter the sump; a concentration sensor connected to the internal volume of the sump, wherein the concentration sensor is configured to measure a concentration of the additive concentrate in the process fluid; a temperature sensor connected to the internal volume of the sump, wherein the temperature sensor is configured to measure a temperature of the process fluid adjacent to the concentration sensor; and a measurement system connected to the concentration sensor and the valve, wherein the measurement system is configured to determine a concentration of the additive concentrate in the process fluid, a level of the process fluid in the sump relative to the concentration sensor, a presence of tramp oil in the process fluid, and a regeneration of the regenerative filter, and wherein the measurement system is configured to open the valve to provide at least one of water and additive concentrate to the process fluid if at least one of the concentration of the additive concentrate in the process fluid is too high, a level of the process fluid in the sump relative to the concentration sensor is too low, and a temperature of the process fluid is too high.

2. The system of claim 1, wherein the measurement system is configured to open the valve when the additive concentrate concentration of the process fluid is determined to be zero indicating the level of the process fluid is lower than the concentration sensor.

3. The system of claim 1 , wherein the measurement system is configured to open the valve when the concentration of the additive concentrate in the process fluid is higher than a desired range and to close the valve when the concentration of the additive concentrate is lower than the desire range.

4. The system of claim 1, wherein the measurement system is configured to open the valve when the measurement system detects an increase in temperature of the process fluid in the sump.

5. The system of claim 4, wherein the measurement system is configured to open the valve after at least one of 1) the increase in temperature occurs longer than a predetermined number of measurement cycles of increasing temperature, and 2) the increase in temperature occurs over a number of cycles that do not coincide with machine cycles.

6. The system of claim 1, wherein the measurement system is configured to open the valve after the temperature remains constant over an extended number of measurement cycles.

7. The system of claim 1, wherein the wherein the measurement system is configured to activate a tramp oil skimmer when the additive concentrate concentration is measured at 100 percent.

8. The system of claim 1, wherein when the additive concentrate concentration is measured at 100 percent for more than a minimum number of measurement cycles, the measurement system is configured to add repair chemistry to the sump.

9. The system of claim 1, wherein when the additive concentrate concentration remains constant over an extended number of data measurement cycles, the measurement system is configured to perform at least one of the following actions: add repair chemistry to the sump, circulate the process fluid in the sump, and provide a notification to a user to recycle the process fluid.

10. The system of claim 1, further comprising a second concentration sensor connected to a mixer tank connected to the feed line.

11. A method for maintaining process fluid in a process fluid maintenance system, comprising: measuring a concentration of an additive concentrate in a process fluid in a sump using a concentration sensor, wherein the sump stores the process fluid in an internal volume defined by the sump, a machine tool is connected to the sump, wherein the machine tool receives the process fluid from the sump, and a regenerative filter is present between the machine tool and the sump, wherein the process fluid passes through the regenerative filter upon being returned to the sump; measuring a temperature of the process fluid adjacent to the concentration sensor in the sump with a temperature sensor; determining a concentration of the additive concentrate in the process fluid, a level of the process fluid in the sump relative to the concentration sensor, a presence of tramp oil in the process fluid, and a regeneration of the regenerative filter, with a measurement system connected to the concentration sensor and a valve wherein the measurement system is configured to determine a concentration of the additive concentrate in the process fluid, a level of the process fluid in the sump relative to the concentration sensor, a presence of tramp oil in the process fluid, and a regeneration of the regenerative filter; and opening the valve with the measurement system to provide at least one of water and additive concentrate to the process fluid in the sump if at least one of the concentration of the additive concentrate in the process fluid is too high, a level of the process fluid in the sump relative to the concentration sensor is too low, and a temperature of the process fluid is too high, wherein opening of the valve allows at least one of water and the additive concentrate to enter the sump.

12. The method of claim 11, further comprising opening the valve when the additive concentrate concentration of the process fluid is determined to be zero indicating the level of the process fluid is lower than the concentration sensor.

13. The method of claim 11, further comprising opening the valve when the concentration of the additive concentrate in the process fluid is lower than a range and to close the valve when the concentration of the additive concentrate is higher than the range.

14. The method of claim 11, further comprising opening the valve when the measurement system detects an increase in temperature of the process fluid in the sump.

15. The method of claim 14, further comprising opening the valve after at least one of 1) the increase in temperature occurs longer than a predetermined number of measurement cycles of increasing temperature, and 2) the increase in temperature occurs over a number of cycles that do not coincide with machine cycles.

16. The method of claim 11, further comprising opening the valve after the temperature remains constant over an extended number of measurement cycles.

17. The method of claim 11, further comprising activating a tramp oil skimmer when the additive concentrate concentration is measured at 100 percent.

18. The method of claim 17, further comprising opening the valve when the additive concentrate concentration is measured at 100 percent for more than a minimum number of measurement cycles.

19. The method of claim 11, further comprising opening the valve when the additive concentrate concentration remains constant over an extended number of data measurement cycles.

20. The method of claim 11, further comprising determining if regeneration of a regenerative filter is occurring too often and isolating the process fluid from the machine tool from the sump by closing a machine tool valve.

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