WO2000059601A1

WO2000059601A1 - Fluid optimization and waste management system

Info

Publication number: WO2000059601A1
Application number: PCT/US2000/009514
Authority: WO
Inventors: Aharon Lieberman
Original assignee: Compositron Corporation
Priority date: 1999-04-06
Filing date: 2000-04-06
Publication date: 2000-10-12
Also published as: AU4223600A

Abstract

A fluid optimization and waste management system including a tank (10) with a removable cover (50) containing a pump, a settling tank (20), and a filtration unit (30).

Description

FLUID OPTIMIZATION AND WASTE MANAGEMENT SYSTEM

FIELD OF THE INVENTION

The present invention relates to fluid optimization and waste management systems, and more particularly, systems for conditioning and removing solids from process fluids.

BACKGROUND OF THE INVENTION

Fluids are routinely used in machining processes. Generally, such fluids are used as a machining lubricant, to cool the workpiece and machine, and to carry machined particles, contaminants, and debris away from the workpiece.

In larger machining operations, fluid may be provided to a machine or machines from a central system. This fluid may be recaptured and re-circulated. However, over time, the fluid's effectiveness in the machining process decreases. Specifically, a build-up of debris, contaminants, and machined particles in the fluid degrades its performance. This degrades workpiece quality, and results in undue wear and damage to the machinery and the fluid circulation system. Also, fluid properties themselves may change, such as specific gravity, viscosity, conductivity, pH, water, lubricant and additive content, and flow rate. For example, in electrochemical grinding applications, electrolytes are contaminated and must be replaced. Thus, at some point, the fluid must be replaced.

Replacement of fluid has several disadvantages. First, replacement entails the cost ofthe fluid itself, as well as the loss of productivity ofthe machinery while the system is being maintained. Also, merely replacing the fluid may be inadequate to remove all harmful elements from the system, and further steps such as flushing the system may be necessary. In addition, disposal of the fluid entails costs and poses environmental concerns when the fluid or the contaminants are harmful or toxic.

Another disadvantage of fluid replacement is that the fluid is either replaced at a predetermined interval, which may not be cost effective, or is monitored to determine when replacement is needed. Such monitoring requires sampling and testing that add cost to the process.

Prior art designs for removing solids from fluids typically use large settling tanks. The tanks are large enough to reduce turbulence within the fluid to a point at which the solids drop out of suspension and settle on the bottom. However, this results in a system that is large, heavy, requires a certain amount of space, and thus entails associated costs.

Prior art designs also typically pass the fluid and/or waste through a separate filtration system. The efficiency of contaminant removal may be increased by using high pressures when circulating the fluid through the filter. The use of high pressures, however, may cause leaks or even explosions, presenting a safety danger. Furthermore, the cost of repair or replacement of the system, in addition to that of lost productivity while the system is inoperable, can be quite substantial.

SUMMARY OF THE INVENTION

The present invention provides a system for efficiently removing contaminants and particles from machining process system fluids.

A system in accordance with an embodiment ofthe present invention reduces time expended maintaining the system.

Additionally, a system in accordance with an embodiment of the invention reduces the fluid content and volume of waste to be disposed. Also, a system in accordance with an embodiment of the invention extracts waste in a solid, semi-dry, compact form that may r-Je easily disposed and processed.

In addition, a system in accordance with an embodiment of the present invention minimizes the level of human interaction with the system and increases overall safety and reliability. Further, a system in accordance with an embodiment of the present invention monitors the operation ofthe system and automatically maintains the system, e.g., by adjusting predefined properties ofthe fluid in the system. A fluid optimization and waste management system in accordance with an embodiment of the present invention includes an optimization tank, a settling tank, a filtration unit, and a cover. The settling tank and filtration unit are preferably modular and may be removed from the optimization tank. The entire system may be connected and disconnected to the equipment it services, and can function as an "add-on" to an existing system.

The optimization tank may include a reservoir for holding the process fluid and an enclosed pump chamber with a pump that supplies process fluid to the process equipment, e.g., machining equipment, utilizing the fluid. Fluid in the pump chamber preferably is isolated from fluid in the reservoir such that fluid may flow from the reservoir to the pump chamber but cannot flow back to the reservoir.

The cover seals the optimization tank, as well as other elements as described below, making the system watertight. The cover may be associated with a mist collector that may utilize a vacuum generator to collect mist from the process equipment. The mist collector may have collector plates upon which the mist condenses and drains into the reservoir or pump chamber.

The invention may also include a monitoring/control unit, preferably programmable, that receives inputs from sensors located throughout the system, compares these inputs to predetermined parameters, particularly regarding fluid characteristics, and controls various electro mechanical devices that adjust fluid properties to desired conditions. For example, the output of the controller may control an additive/concentrate injection mechanism that injects additives into the pump chamber in accordance with the controller output.

Process fluid from process equipment enters into the settling tank, preferably via a primary filter that removes large particles. The settling tank includes a plurality of settling chambers. A settling chamber is designed to maximize the amount of solids that settle at the bottom ofthe settling chamber. Chambers are separated by a cascade wall having at least one cascade orifice therethrough configured and positioned such that fluid, but not settled particles, passes from one chamber to the next. A settling chamber also may include a skimmer to remove oil and floating contaminants. Cleaned fluid passes out ofthe settling tank into the reservoir through an exit orifice in the last settling chamber.

A filtration unit in accordance with an embodiment ofthe invention may include a filtrate pump that pumps the settled and skimmed contaminants from the settling tank through a filter arrangement that is preferably contained in a filtration unit housing and is preferably locked by a press lock mechanism.

The filter arrangement includes at least one waste collection bay, including an open frame surrounded by filtration medium, e.g., a bag or cloth, and end plates having filtration collection surfaces located against the openings of the frame. Fluid may flow from the filtrate pump into the waste collection bay, where the filtration medium captures the solids, and filtered liquid passes through the filtration medium and flows into the reservoir. The invention may include a center plate having opposing filtration collection surfaces between predefined groups of waste collection bays. A press lock mechanism in accordance with an embodiment ofthe invention includes a pressure plate, support mechanism therefor, and a linkage mechanism. The support mechanism allows axial movement ofthe pressure plate. Translation ofthe linkage mechanism moves the pressure plate in an axial direction against the filter arrangement. This compresses the components of the filter arrangement against each other, forming a sealed filter arrangement.

The system ofthe invention may include a compressor, optionally associated with a heater, for pumping air into the at least one waste collection bay and, thereby, its contents. The waste is dried into a compact form that is easily removed and disposed of and may be less harmful due to chemical changes occurring during the drying process. In accordance with an embodiment of the present invention, process fluid enters the system into the settling tank, preferably through the primary filter. In the settling chambers ofthe settling tank, solids and particles are forced out of suspension and are deposited at the bottom ofthe settling chambers, while oils, contaminants and lighter particles rise toward the top ofthe chambers and preferably are removed by a skimmer. Fluid in the last settling chamber, now relatively free of contaminants, flows through the exit orifice into the reservoir.

Waste from the bottom of a settling chamber or skimmer is then pumped into the filter arrangement by the filtrate pump. The waste enters the waste collection bay where it is filtered out of the processing solution by the filtration medium. The filtered fluid flows into the reservoir, where any remaining contaminants tend to settle at the bottom of the reservoir, and clean fluid then flows into the pump chamber.

In some embodiments ofthe invention, mist from the process equipment may be drawn into the mist collector, condensed, and drained into reservoir or the pump chamber. The monitoring/control unit adjusts operating parameters of fluid in the pump chamber according to signals received from the sensors and its programming. For example, the monitoring/control unit may measure, via the sensors, fluid level, specific gravity, conductivity, pH, foreign particle concentration, temperature, viscosity, flow rate, pressures and pressure drop, and oxygen degradation. The monitoring/control unit communicates with valves, pumps, and additive/concentrate injection tanks, causing them to introduce water, process fluid, rust inhibitors, lubricants, soluble oils or other additives. In electrochemical grinding applications, for example, the monitoring/control unit may be used to control automatic injection of concentrated electrolytes to increase fluid conductivity, pH, or specific gravity. The optimized fluid is then pumped back to the process equipment.

When the filter cannot efficiently hold additional solids, the filtrate pump may be shut down. The compressor may then pump pressurized warm air into the filter, drying the waste.

In order to remove the waste, the press lock may be disengaged by translating the linkage mechanism, which draws the pressure plate away from the filter arrangement to release the compression force. The cover and the waste collection bay may then be removed for disposal ofthe semi-solid waste blocks therein. The waste blocks removed from the filtration unit bays may then be disposed.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully from the following detailed description of a preferred embodiment of the invention, taken in conjunction with the accompanying drawings of which:

Fig. 1 is a perspective view of a fluid optimization and waste management system according to an embodiment ofthe present invention;

Fig. 2 is a perspective view of an optimization tank according to an embodiment ofthe present invention;

Fig. 3 is a perspective view of a settling tank according to an embodiment ofthe present invention; Figs. 4a and 4b are, respectively, a top and side view of a filtration unit according to an embodiment ofthe present invention.

Figs. 5a and 5b are, respectively, a front and side view of a waste collection bay frame according to an embodiment of the present invention; Fig. 6a, is a front view of a filtration unit end plate according to an embodiment ofthe present invention;

Figs. 6b and 6c are, respectively, a side view of a filtration unit end plate, and a side view of a filtration unit center plate according to an embodiment ofthe present invention; Fig. 7 is a detail of a filtration collection surface according to an embodiment of the present invention;

Fig. 8 is a schematic flow diagram of fluid flow through a filtration unit according to an embodiment ofthe present invention;

Fig. 9 is a schematic flow diagram of air flow through a filtration unit according to an embodiment ofthe present invention;

Fig. 10 is a schematic block diagram of a fluid optimization and waste management system including a monitoring/control unit according to an embodiment of the present invention;

Fig. 11 is a view of settling chamber cascade walls according to an embodiment of the present invention; and

Fig. 12 is a perspective view of a settling chamber according to an embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION Referring to Fig. 1 , a fluid optimization and waste management system 1 in an embodiment ofthe invention includes an optimization tank 10, a settling tank 20, a filtration unit 30, a monitoring/control unit 40, and a cover 50. Preferably, settling tank 20 and filtration unit 30 are modular, i.e., designed for convenient access to, removal from, and installation into predefined locations in optimization tank 10. Optimization tank 10 has sufficient structural integrity so that any leaks or failures in the system are contained within optimization tank 10 and, thus, do not endanger other equipment or persons. In one embodiment ofthe invention, the system further includes an additive/concentrate injection mechanism 60.

A fluid return line 70 transports process fluid from process equipment using the fluid (not shown), such as machining equipment, for example, electrochemical grinding apparatus, to settling tank 20 of system 1. A fluid supply line 72 carries processed fluid from system 1 back to the process equipment. The fluid may be used for cooling, lubricating and waste collection, as is known in the art, depending on the type of equipment. Referring now also to Fig. 2, optimization tank 10 includes a reservoir 100 for holding the process fluid and an enclosed pump chamber 102. A pump 104 that resides within pump chamber 102 supplies process fluid to the process equipment through supply line 72. Preferably, supply line 72 is connected to a receptacle 106, allowing convenient connection and disconnection with system 1. This allows system 1 to be retrofitted to existing equipment or to readily be isolated from the equipment, e.g., for maintenance.

Fluid may pass from reservoir 100 to pump chamber 102, but preferably may not flow from pump chamber 102 to reservoir 100, isolating reservoir 100 and settling tank 20 from pump chamber 102. This may be accomplished, for example, by a pump chamber orifice 1 14 located near the top of pump chamber 102. When fluid in reservoir 100 reaches the height of pump chamber orifice 114, the fluid flows into pump chamber 102. Pump 104 maintains the fluid level in pump chamber 102 below the height of pump chamber orifice 114, thus preventing fluid from flowing back into reservoir 100.

Referring now also to Figure 10, monitoring/control unit 40 is connected to a plurality of sensors 44 located throughout system 1, and measures various fluid operating parameters against preset conditions. For example, via sensors 44, monitoring/control unit 40 may measure such parameters as fluid level, specific gravity, conductivity, pH, foreign particle concentration, temperature, flow rate, viscosity, pressures and pressure drop, oxygen degradation and others. Monitoring/control unit 40 also is connected to one or more electromechanical devices, e.g. valves 46, pump 104, and additive/concentrate injection mechanism 60, for example, a tank. Monitoring/control unit 40 receives input from sensors 44 and, based on predetermined criteria evaluated by a processor in monitoring/control unit 40, communicates control signals to electro mechanical devices, as noted above. Monitoring/control unit 40 is preferably programmable. Programming may include, for example, fuzzy logic.

The fuzzy logic may control the system ofthe invention, based on a set of criteria governed by hierarchies which determine the operating ranges of the system. The fuzzy logic may evaluate relationships between parameters and govern the system by selecting the most effective parameter to alter in order to achieve desired effects. Fuzzy logic may employ a statistical database to prevent the system from repeating prior unacceptable conditions. The statistical database may be used to "learn" the desirable relationships between parameters and, thus, to improve the conclusions ofthe logic. For example, if a system would overload its electrical transformer, generate unacceptable loads on the spindle, or alter any other parameter undesirably in order to increase production, it would reduce output to maintain all process variables within their respective operating ranges. The operator can override unacceptable criteria to improve the desired quality of machine operation and the fuzzy logic may respond by altering the parameters in order to achieve the desired effect. The fuzzy logic may use this information to form its conclusions of acceptable criteria.

Monitoring/control unit 40 further may include a user interface 42, (Fig. 2) e.g., a touch screen, whereby current fluid conditions may be displayed and/or desired ranges for operating parameters may be programmed. When fluid parameters are outside the desired ranges, monitoring/control unit 40 may communicate control signals and the fluid characteristics may be adjusted, either automatically or by an operator through user interface

42. For example, water or process fluid may be introduced into pump chamber 102 as needed, or monitoring/control unit 40 may communicate control signals to additive/concentrate injection mechanism 60, causing it to inject additives into pump chamber 102, e.g., to increase the specific gravity, conductivity, concentration ofthe fluid, or to introduce other additives such as rust inhibitors, soluble oils, and lubricants. Monitoring/control unit 40 may also control, for example, the temperature of the fluid. In one embodiment of the invention, this is accomplished by a heater 392, which is activated by monitoring/control unit 40 when sensors detect that fluid temperature is below room temperature. Maintaining fluid temperature at least at room temperature may provide advantages in the machining process. For example, in electrochemical grinding applications, maintaining the electrolyte at a substantially constant temperature year round ensures that the electrolyte has a substantially constant relative conductivity year round. Heated fluids are generally more reactive in the process and provide a more rapid metal removal rate. Preferably, heater 392 is located at the bottom ofthe outside of optimization tank 10, most preferably directly beneath pump chamber 102. In a preferred embodiment, where reservoir 100 and settling tank 20 are isolated from pump chamber 102, agitation of fluid in reservoir 100 and settling tank 20 by turbulence generated by pump 104 is minimized. This prevents solids that have settled to the bottom of reservoir 100 and settling tank 20 from being re-suspended and taken up by pump 104. Furthermore, the smaller volume of fluid within pump chamber 102 is easier to monitor and its properties easier to adjust than the larger volume within reservoir 100.

Preferably, optimization tank 10 has a rim 108 upon which settling tank 20 and filtration unit 30 are mounted. In one embodiment, rim 108 has a mounting hole 110. Settling tank 20 and filtration unit 30 have a hole 250, 350 that aligns with mounting hole 110 when settling tank 20 and filtration unit 30 and mounted on the rim (Fig. 1). A pin 112 inserted through hole 250, 350 and mounting hole 110 maintains the position of settling tank 20 and filtration unit 30 with respect to rim 108. Rim 108 is positioned in optimization tank 10 so that settling tank 20 and filtration unit 30 do not rest on the bottom of optimization tank 10. This aids in settling of any remaining particles in optimization tank 10. Rim 108 also receives a seal

52, preferably rubber, on cover 50. Seal 52 is compressed when cover 50 is assembled to optimization tank 10, making system 1 watertight.

Preferably, cover 50 includes a filter cover 51 covering filtration unit 30 that is removable from cover 50. This allows access to filtration unit 30 without shutting down the rest of system 1 or removing the entire cover 50. Cover 50 also preferably includes a mist collector 80 that collects mist from the process equipment. For example, a vacuum generator 82, e.g., a vacuum pump, generates a vacuum to draw mist from the process equipment through a mist line 86 into optimization tank 10 or the mist collector 80. Mist then impinges on collector plates 84, causing the mist to condense. Mist in optimization tank 10 may also impinge on collector plates 84 and condense. Mist collector 80 is designed such that the condensed fluid then drains into pump chamber 102.

Cover 50 may also have an inlet connection 54 connected to fluid return line 70. Inlet connection 50 is positioned such that fluid flows into settling tank 20. Preferably, inlet connection 54 is removably mountable such that the type of connection may be changed. Thus, any type of connection on return line 70 may be accommodated.

Referring further to Fig. 3, in a preferred embodiment of the invention, settling tank 20 has a plurality of settling chambers. An exit orifice 202 in settling tank 20 allows fluid to flow into reservoir 100. Although the number of chambers for effective operation is determined by the particular application, settling tank 20 preferably has two or more chambers, for example the five chambers shown in Fig. 3, 200a, 200b, 200c, 200d, 200e.

In a preferred embodiment, the first settling chamber 200a is larger than chambers 200b, 200c, 200d, 200e to reduce agitation. Although the size of the chambers depends upon the application, in electrochemical grinding applications, for example, the first settling chamber 200a may have a volume of about 5 gallons, while the rest ofthe chambers have a volume of about 1-2 gallons.

Chambers 200a, 200b, 200c, 200d, 200e are preferably separated by cascade walls 204a, 204b, 204c, 204d. Cascade walls 204a, 204b, 204c, 204d have cascade orifices, 206a, 206b, 206c, 206d, respectively, that are configured and positioned therein, depending on the application and the dimensions ofthe chambers, such that fluid passes through the orifices but particles that have settled at the bottom of any of settling chambers 200a, 200b, 200c, 200d will not pass to the next chamber. The cascade orifices 206a, 206b, 206c 206d are located at least a sufficient height from the bottom of its associated settling chamber, for example, 5 inches in some electrochemical grinding applications, to achieve a hydraulic head therein. This head helps settle suspended solids and holds settled particles toward the bottom ofthe settling chambers. Preferably, cascade orifices 206a, 206b, 206c, 206d are circular and are not aligned with each other to reduce turbulence and, thereby, increase settling. Cascade orifices 206a, 206b, 206c, 206d, may be, for example, 1 inch in diameter in, for example, certain electrochemical grinding applications.

In the embodiment described above wherein settling chambers 200b, 200c, 200d, 200e have a volume of about 1-2 gallons, cascade orifices 206a, 206b, 206c, 206d may have, for example, an arrangement as shown in Figure 11. Preferably, the cascade orifices are located progressively lower in their respective cascade walls. For example, while cascade orifices 206a, 206b may be located 1 inch and 8 inches below the tops of cascade walls 206a,

206b, respectively, cascade orifices 206c, 206d may be located 1.5 inches and 9 inches below the tops of cascade walls 206c, 206d, respectively. More preferably, exit orifice 202 is located further down from the top of settling tank 20 than cascade orifice 206c.

In a preferred embodiment shown in Figure 12, exit orifices 206a, 206b, 206c, 206d have a hemispherical contour with the convex surface oriented opposite flow direction.

This minimizes the undesirable flow of solids through the exit orifices.

The bottoms of setting chambers 200a, 200b, 200c, 200d, 200e are connected to chamber drain lines 226a, 226b, 226c, 226d, 226e, respectively, that connect the chambers to filtration unit 30. Preferably, settling tank 20 has a sloped bottom 230 such that settled material tends to settle a low side 232 in settling tank 20. Chamber drain lines 226a, 226b,

226c, 226d, 226e are preferably connected to settling tank 20 along low side 232 to maximize drainage of settled material from settling tank 20.

In one embodiment in ofthe invention, settling tank 20 may have a primary filter 208 that may be located at inlet connection 54. Primary filter 208 removes large chips and waste particles. This helps prevent clogging, decreases turbulence of fluids entering settling tank 20, and thus increases the efficiency of settling tank 20 in removing particles from the fluid. Preferably, primary filter 208 is removable and/or disposable so that the large waste may be removed periodically. In addition, settling tank 20 may include at least one floating skimmer that removes oil, foam, and other floating contaminants. The number of skimmers used is determined by the specific application. In the embodiment described herein, settling chambers 200a, 200b, 200c, 200d, 200e each have a skimmer 210. Each of skimmers 210a, 210b, 210c, 210d, 210e are similar in design and function as described below. Each has a bucket-shaped main body 212 with an open end 216 for holding collected material. Main body 212 is formed of a material that floats in the process fluid. Main body 212 is mounted on a pivot 214 with open end 216 oriented toward inlet connection 54. Pivot 214 is offset relative to main body 212 toward open end 216 such that main body 212 floats in a horizontal orientation in settling tank 20. In this orientation, floating waste fluid and contaminants may flow into open end 216, and are collected in main body 212. Pivot 214 is positioned in settling tank 20 such that when main body 212 is in a vertical orientation, fluid may not flow into open end 216 and is blocked by main body 212. A rubber skirt 218 around open end 216 blocks fluid flow along the sides of settling tank 200 and is preferably configured to direct fluid into main body 212.

Pivot 214 is connected to a switch 220 that opens a valve 222 when activated by rotation of pivot 214. Main body 212 is connected to valve 222 by a skimmer drain line 224. When main body 212 is in a horizontal orientation, valve 222 is closed. When main body 212 is rotated to a vertical orientation, pivot 214 consequently rotates, activating switch 220, which opens valve 222, which is connected to filter press 30.

Referring to Figs. 4a and 4b, filtration unit 30 includes a filtration unit housing 300, a filtrate pump 310, a filter arrangement 320, and a press lock 370. Filtration unit housing 300 contains filter arrangement 320 and press lock 370 and is of sufficient structural strength to withstand the forces exerted thereby. Preferably, corrugated steel plates 302 are welded to the ends of filtration unit housing 300 to provide it with adequate strength, stiffness, and fatigue resistance.

Referring to Fig. 8, filtrate pump 310 draws collected solids from settling tank 20 through chamber drain lines 226a, 226b, 226c, 226d, 226e (Fig. 3)and skimmer drain lines 224a, 224b, 224c, 224d, 224e (Fig. 3) and transfers them to filter arrangement 320. Filtrate pump 310 may be any pump capable of transporting heavy particulate fluids, e.g., a double acting diaphragm pump. Preferably, a flow sensor 44b monitors the fluid flow exiting filter arrangement 320. Filtrate pump 310 also preferably transports the particulate fluid to filter arrangement 320 under high pressure, most preferably at about 65 to about 85 psi. In one embodiment ofthe invention, monitoring/control unit 40 operates filtrate pump 310 on a predetermined cycle. The length of this cycle may depend, for example, on the volume of fluid being filtered, the volume of solids being generated by the machining operation, and the size and type of solids generated. Preferably, a sensor 44a in settling tank 20 monitors clarity ofthe fluid there and operates filtrate pump 310 so long as contaminant levels are above a predetermined level. Any sensor capable of monitoring clarity may be used, e.g., float, photocell, fiberoptic sensor, etc.

Referring also to Figs. 5a, 5b, 6a, 6b and 7, filter arrangement 320 includes at least one waste collection bay 330, preferably a plurality of waste collection bays 330. Each waste collection bay 330, preferably plastic, surrounded by a filtration medium 334 (Fig. 4b), preferably a cloth filtration bag as is known in the art. One skilled in the art will recognize commercially available material and synthetic cloths. Filtration bag 334 is capable of filtering solids while allowing fluid to pass through. Preferably, waste collection bay 330 is provided with a handle 336 (Figs. 4a, 4b) for easy removal from filter arrangement 320. Filter arrangement 320 further includes an end plate 364 (Figs. 4a, 4b) located against the ends of waste collection bays 330. End plate 364 is of generally similar profile to waste collection bay 330 and is of sufficient strength to withstand the forces exerted upon it by press lock 370. Endplate 364 includes a filtration collection surface 360 (Fig. 7) that has collection passageways 362 for collecting fluid that passes through filtration bag 334. In a preferred embodiment, filtration collection surface 360 is made from plastic and is installed in a cavity 365 of end plate 364. In embodiments of the invention having more than one waste collection bay 330, a center plate 366 (Fig. 4a) similar to endplate 364, but having two opposing filtration collection surfaces 360, may be utilized between them. End plates 364 and center plate 366 (in multi-bay embodiments ofthe invention) provide filter arrangement 320 with structural strength so that filtration collection surfaces 360 and filtration media 334 are not damaged by press lock 370.

Frames 332, end plates 364, and center plate 366 each include at least one bay supply line 338, at least one lower bay return line 367, and at least one upper bay return line 368. These are positioned so that the bay supply lines 338 are aligned, the lower bay return lines 367 are aligned, and upper bay return lines 36 are aligned when installed in filter arrangement 320. The bay supply lines 338 are connected to filtrate pump 310. Lower bay return lines 367 and upper bay return lines 368 are connected to reservoir 100. Each frame 332 (Fig. 5a) includes at least one inlet passage 340 extending therethrough from bay supply line 338 to waste collection bay 330. This allows fluid to flow through bay supply line 338 and inlet passageway 340 into waste collection bay 330. Endplate 364 and center plate 366 (Fig. 6a) include at least one outlet passage 369 therethrough extending from each bay return lines 368 and 367 to collection passageways 362. Thus, cleaned fluid may flow from collection passageways 362 to reservoir 100.

Press lock 370 (Fig. 4a) provides sufficient compression force such that fluid does not leak out between components of filter arrangement 320. Thus, all fluid delivered to filtration unit 30 by filtrate pump 310 must flow through waste collection bay 330 of filter arrangement 320. Press lock 370 preferably includes a pressure plate 372, support mechanism

376, and a linkage mechanism 378. Support mechanism 376 is mounted to filtration unit housing 300 and also mounted to pressure plate 372. Support mechanism 376 supports the weight of pressure plate 372 and allows axial movement thereof. In a preferred embodiment, support mechanism 376 includes a telescoping cylinder. It will be appreciated that any other suitable support mechanism as is known in the art may be used.

Preferably, linkage mechanism 378 (Fig. 4b) includes a first link 380, a second link 382, and a third link 384. First link 380 is pivotally mounted to filtration unit housing 300. Third link 384 is pivotally mounted to pressure plate 372. First link 380 and third link 384 are pivotally connected to each other, and second link 382, by pin 386. When second link 382 is drawn downward by an actuator (not shown), first link

380 and third link 384 rotate around pin 386, translating pressure plate 372 in an axial direction. Pressure plate 372 presses against filter arrangement 320, compressing end plates 364, filtration collection surfaces 360, waste collection bays 330, and center plate 366 together and against corrugated steel plate 302. In one embodiment ofthe invention, pressure plate 372 includes a pressure drum 373 mounted to support mechanism 376 and linkage mechanism 378, and a flex plate 374 mounted to pressure drum 373. Flex plate 374 may deflect to a small degree so as to ensure optimum contact with filter arrangement 320, thus providing evenly distributed pressure on filter arrangement 320, which helps prevent fluid from leaking between the components. In addition, flex plate 374 may be removed and replaced to accommodate different filter arrangement 320 configurations without having to modify other components of press lock 370.

The system ofthe invention may further include a compressor 390 (Fig. 4a) to provide pressurized air to waste collection bays 330 to dry the waste contents. The compressor is utilized before the waste is removed from filter arrangement 320. In addition, compressor 390 may be connected to heater 392 to warm the compressed air, aiding the drying process. Drying ofthe waste allows it to be removed in a semi-dry, compact form, allowing for easier, safer, and cleaner handling and disposal ofthe waste without the need to contain or dispose of liquid. Moreover, in electrochemical grinding applications, for example, drying may transform certain waste components into a less toxic form. For example, hexavalent chrome is a typical byproduct of electrochemical processes and is toxic. Drying converts it into trivalent chrome, which is inert.

In an embodiment ofthe invention, as shown in Figure 9, compressor 390 and heater 392 are connected to upper bay return 368 via air supply valve 394, which is a 3-position valve. Air from compressor 390 flows through upper bay return line 368, outlet passage 369, collection passageways 362 (Fig. 7) and filtration media 334 into waste collection bay 330, where it dries the collected waste. Moisture-carrying air then flows through lower bay return line 367 out of filter arrangement 320. Preferably, a bay supply line valve 398 is located in line between filter arrangement 320 and filtrate pump 310 and prevents air from bypassing filter arrangement 320 through bay supply line 338. Also preferably, a humidity sensor 396 monitors the level of moisture in the air exiting through lower bay return line 367 and communicates to monitoring/control unit 40 an input responsive to the moisture level . When the moisture level exceeds a predetermined threshold, monitoring/control unit 40 provides an output that operates compressor 390 and heater 392 until the waste is sufficiently dry. When humidity falls below a predetermined threshold, monitoring/control unit 40 shuts down compressor 390 and signals an operator that the waste is dry. In a preferred embodiment, monitoring/control unit 40 also monitors inputs from sensors 44a, 44b and controls the operation of air supply valve 394 and bay supply valve 398 in accordance with the monitored sensor-inputs.

As one skilled in the art will recognize, the above description of filtration unit 30 is but one embodiment ofthe present invention, and other suitable filter arrangements that pressurize the filtrate and dry the waste may be used in conjunction with the present invention. In another embodiment ofthe invention, filtration unit 30 can accommodate machining operations that generate large chips. Also, those skilled in the art will understand that the above- described air flow path through filter arrangement 320 is only one manner by which air may be passed therethrough to dry the waste according to the present invention. In accordance with a preferred embodiment of the above-described fluid optimization and maintenance system, process fluid enters system 1 through fluid return line 70 and inlet connection 54 in cover 50 into settling tank 20. The fluid passes through primary filter 208 where large particles and wastes, such as machining chips, are removed. The fluid continues into settling chambers 200a, 200b, 200c, 200d, 200e, successively, through cascade orifices 206a, 206b, 206c, 206d. The downward direction and velocity of the flow and gravitation forces tend to force solids and particles out of suspension and deposit them at the bottom of settling chambers.

Oils, contaminants and lighter particles, however, rise toward to the tops ofthe chambers and are removed by skimmers 210a, 210b, 210c, 210d, 210e. In each settling chamber, wastes at the surface flow into open end 216 of main body 212 ofthe skimmer , which is floating in a horizontal orientation, and are collected therein. When the weight of contaminants is great enough to overcome the flotational force of main body 212, main body 212 rotates to a vertical orientation and drains as described above. When the main body 212 is sufficiently emptied, its flotational force returns it to its prior orientation. Fluid toward to top of chamber 200e, which is relatively free of both solid particles and other contaminants, then flows through exit orifice 202 into reservoir 100.

Waste from the bottom of settling chamber 200a, 200b, 200c, 200d, 200e and from skimmers 210a, 210b,210c, 210d, 210e are pumped into filter arrangement 320 by filtrate pump 310. The waste enters waste collection bays 330 and is filtered by filtration bags 334.

Solid particles remain in filtration bags 334 while clean fluid passes through it to reservoir 100.

As waste collection bay 330 collects waste, the internal pressure on the filter arrangement 320 components increases. As noted above, filtration unit housing 300 retains the components. However, in an embodiment having plastic frame 332 and filtration collection surfaces 360, these components expand in the axial direction while the other components do not, increasing the compression of filter arrangement 320 components and the sealing between them, reducing the possibility of leaks.

Any contaminants remaining in the fluid in reservoir 100 tend to settle to its bottom, while fluid flows into pump chamber 102. In addition, mist from the process equipment is drawn into mist collector 80 through mist line 86 by vacuum generator 82. The mist condenses on collection plates 84 and drains into pump chamber 102. Here, as described above, monitoring/control unit 40 measures flufd operating parameters and adjust them in order to optimize the process fluid. The optimized fluid is then pumped back to the process equipment by pump 104.

When filter arrangement 320 cannot efficiently hold additional solids, filtrate pump 310 is shut down. Preferably, this is done automatically by monitoring/control unit 40 when, for example, the back pressure from filter arrangement 320, as measured by sensors 44, is greater than the pressure produced by pump 104, or monitoring/control unit 40 measures a predetermined pressure drop or lack of fluid flow as measured by sensor 44b. Monitoring/control unit 40 communicates a signal to cause bay supply line valve 398 to close and air supply valve 398 to open, isolating filter arrangement 320 from the fluid flow.

Compressor 390 then pumps pressurized air warmed by heater 392 into filter arrangement 320, drying the waste as discussed above.

In order to remove the waste, press lock 370 is disengaged by moving second link 382 upward, which withdraws pressure plate 372 from filter arrangement 320 and removes the compression force on it. Filter cover 51 is then removed from filtration unit, and waste collection bays 330 are removed. Frames 332, filtration media 334, end plate 364, center plate 366 and filtration collection surface 360 are cleaned of solids, and filtration unit 30 and filter cover 51 are reassembled. Press lock 370 is then re-engaged and filtrate pump 310 may be then restarted. The solids removed from filtration unit 30 may be placed in a container and either disposed of or sent to a reclamation facility to remove valuable or hazardous materials.

One should note that with filtrate pump 310 shut down, filter cover 51 may be removed and filter arrangement 320 cleaned without shutting down pump 104. This permits the process equipment to continue to receive process fluid and produce product without interruption. Thus, the present invention allows continuous maintenance of process fluids to provide clean, optimized fluid to any process application. Such continuous maintenance is performed without disabling the equipment for maintenance, thereby increasing productivity. Modular embodiments of the invention permit maintenance ofthe optimization and maintenance system to be performed in a minimum amount of time. Further, waste products removed from the process fluid are efficiently disposed in an environmentally controllable manner.

While the embodiments ofthe invention shown and described herein are fully capable of achieving the results desired, it is to be understood that these embodiments have been shown and described for pu oses of illustration only and not for purposes of limitation. Other variations in the form and details that occur to those skilled in the art and that are within the spirit and scope ofthe invention are not specifically addressed. Therefore, the invention is limited only by the appended claims.

Claims

1. A fluid optimization and waste management system comprising a sealed optimization tank having a removable cover, a pump that pumps process fluid through the system, a settling tank within said optimization tank for separating waste from process fluid, and a filtration unit within said optimization tank for filtering the waste separated by said settling tank.

2. The system of claim 1 further comprising a monitoring/control unit that receives inputs responsive to at least one parameter of the system and provides an output to control at least one parameter ofthe system.

3. The system of claim 1 wherein said cover includes a mist collector.

4. The system of claim 1 wherein said optimization tank includes a reservoir for holding fluid and a pump chamber at least partly separated from said reservoir wherein said pump is located in said pump chamber.

5. The system of claim 4 wherein fluid may flow from said reservoir to said holding chamber while fluid may not flow from said pump chamber to said reservoir.

6. The system of claim 1 further comprising an additive/concentrate injection mechanism for injecting an additive into said process fluid.

7. A settling tank for cleaning a fluid having solid and liquid contaminants therein, comprising a plurality of settling chambers, including an inlet settling chamber and an outlet settling chamber, each settling chamber being separated from a successive settling chamber by a cascade wall therebetween, said cascade wall having at least one orifice configured and positioned so that fluid may flow from each settling chamber to the successive settling chamber while solids settle to the bottom of each settling chamber.

8. The settling tank ofclaim 7 having at least three settling chambers separated by cascade walls, wherein the orifices ofthe cascade walls are not aligned.

9. The settling tank of claim 8 wherein said orifice is substantially circular.

10. The settling tank of claim 9 wherein said orifice has a diameter of less than about two inches.

1 1. The settling tank of claim 7 further comprising a primary filter, associated with said inlet chamber, for filtering coarse waste in said fluid.

12. The settling tank of claim 7 wherein said inlet chamber has a larger volume than the remainder of said plurality of settling chambers.

13. The settling tank of claim 7 further comprising at least one skimmer mounted in at least one of said settling chambers, for collecting and removing waste near the top of said at least one settling chamber.

14. A filtration unit for filtering solid waste from a process fluid comprising: a filtration unit housing; a filter arrangement within said filtration unit housing for extracting said solids from said fluid, said filter arrangement including a plurality of separable elements substantially filling a cross-section of said housing; and a press lock within said filtration unit housing for pressing said elements together in locking engagement.

15. The filtration unit of claim 14 wherein said filter comprises: at least one waste collection bay including an open frame surrounded by a filtration medium; and an end plate located against an end of said waste collection bay, said end plate including a filtration collection surface having collection passageways for collecting fluid that passes through said filtration medium.

16. The filtration unit of claim 15 further including at least two waste ^"collection bays, at least two filtration collection surfaces, and a center plate between said at least two waste collection bays having two opposing cavities for receiving two filtration collection surfaces.

17. The filtration unit of claim 14 wherein said press lock comprises: a pressure plate; a support mechanism for supporting said pressure plate; and a linkage mechanism for translating said pressure plate in response to movement of said linkage mechanism.

18. The filtration unit of claim 17 wherein said linkage mechanism comprises first, second, and third links, said first link pivotally mounted to said filtration unit housing, said third link pivotally to said pressure plate and also pivotally mounted to said first and second links by a pin, wherein movement of said second link causes movement of said third link to translate said pressure plate.

19. The filtration unit of claim 17 wherein said support mechanism comprises a telescoping cylinder.

20. The filtration unit of claim 14 further comprising means for drying the solid waste filtered by said filter arrangement.