US2482302A - Filtering system - Google Patents

Description

Sept. 20, 1949. o. M. SIJMMERS 2,482,362

FILTERING SYSTEM Filed April 25. 1946 5 Sheets-Sheet 1 uvEN TOR 86 orro M. SUMMERS Sept. 20, 1949. o. M. SUMMERS FILTERING SYSTEM 5 Sheets-Sheet 2 Filed April 25, 1946 Iuvsurcm OTTO M. SUMMERS QT 5W ATTORNEY!) P 1949- o. M. SUMMERS 2,482,302

FILTERING SYSTEM Filed April 25. 1946 5 Shee'ts-Sheet 5 I "reams OTTO M. SUMMER Ar-roRNEyz 5 Sheets-Sheet 4 m MM 7 m w m 5 m w 0 Q Q N 5 a F 0 Sept. 20, 1949. o. M. SUMMERS FILTERING SYSTEM Filed April 25, 1946 H h Em nn 9 w rill I/ 7 vnw aa .voulllllb'dlt g 6 ll 00 l ZVIAVIV/l? 4 Sept. 20, 1949. o. M. SUMMERS 2,482,302

FILTERING SYSTEM 5 sheets-sneak 5 Filed April 25, 1946 INVENTOR OTTO M SUMMERS Patented Sept. 20, 1949 FILTERING SYSTEM Otto M. Summers, Glasgow, Ky., assignor to The Thompson Grinder Company,

Springfield,

Ohio, a corporation of Ohio Application April 25, 1946, Serial No. 664,919

13 Claims. (Cl. 210-190) This invention relates to filtering systems and particularly to filtering systems for use in connection with machine tools such as lathes, grinders, etc. which have circulating cooling or lubricating fluids.

In machine work it is usually necessary to bathe the cutting member and the workpiece being cut with a lubricant or a coolant in order to be able to produce high quality products at the rate of speed necessary for economical production. The fluid so employed is circulated from a sump or reservoir by a suitable pumping means and is returned to the reservoir, generally by gravity flow.

Since machining operations remove metal from the workpiece, the cooling or lubricating fluid picks up small particles of material during its passage through the aforementioned circulatory system. In many cases, especially in the case of grinding machines, a good bit of the particles thus picked up are very fine and have a tendency to be carried with the fiuid completely through the system and returned to the point of use of the fluid. This is undesirable in that a workpiece having a high finish can only be produced if the cooling and lubricating fluid is free of particles of metal and abrasive.

The fluid is also sometimes employed for lubricating the machine ways and, to this end, is preferably free of all particulate foreign material such as dust, metal fragments and abrasive residue.

Accordingly, it is important that the fluid be properly and adequately filtered and this filtering action is preferably a continuous process so that the fluid is maintained in a clean and useable condition at all times.

The principal object of the present invention is to provide a filtering system which has a high degree of efficiency in removing particles and which is readily serviced and cleaned. The inherent and basic means by which this exceptionally high degree of efiiciency is accomplished in a large volume of coolant liquid with a minimum of flow resistance, and which differentiates this system from conventional types, is the arrangement of large area bags of relatively coarse and highly adsorptive fabric with restrictive overflow means, in such manner as to agglomerate by adsorptive action and permanently trap exceedingly fine particles which are removed from the system through the routine change of filter bags.

This agglomeration is a constant process and while maximum effect is achieved in that portion of coolant fiuid that passes through the coarse meshes of the fabric, it acts with only a slight decrease in eificiency on the portion that overflows, when the timely replacement of bags is neglected.

This arrangement assures a positive and unfailing fiow of coolant liquid under any and all conditions, which is an absolute requisite of a practical grinding operation, as a sudden reduction of flow of as little as 10% would under some conditions result in a total loss of the workpiece as well as partial loss of wheel form.

Another object is to provide a filtering system for fluids such that the residue collected by the filter is easily removed therefrom to place the filter in clean condition.

Another object is to provide a filtering system in which there is an auxiliary reservoir that collects the residue.

Still another object is to provide a filtering system in which the fluid being filtered is passed through a filtering medium which agglomerates the exceedingly fine particles into particles of greater size which are more easily separated from the fiuid either by straining or by settling.

These and other objects and advantages become more apparent upon reference to the following specification taken together with the accompanying drawings in which:

Figure 1 is a perspective view of a grinding ma chine having a filtering system according to this invention. associated therewith;

Figure 2 is a plan section taken substantially along the line 22 of Figure 1;

Figure 3 is a vertical section taken substantially along the line 3-3 of Figure 1 and showing the primary and secondary filtering units;

Figure 4 is a vertical section taken along the line 4-4 of Figure 3 showing the primary filtering unit and the auxiliary settling or diffusing tank;

Figure 5 is a section on the line 5-5 of Figure 4 and shows the settling or diffusing tank more in detail;

Figure 6 is a section taken on the line 66 of Figure 1 and shows the pumping units;

Figure 7 is a fragmentary view showing the manner of suspending the filtering bags in the units;

Figures 8 and 9 are fragmentary views showing tdetails of the control valves in the filtering sys- Figure 10 is a perspective View of the top of a tank showing a partition dividing the tank into upper and lower portions; and

Figure 11 is a vertical section taken intermediate the section shown in Figure 3 and the rear the path of fluid flow through the primary and secondary filters.

Referring to the drawings, there is shown a grinder in Figure 1 having a bed l and a table I2 reciprocable thereon. A grinding wheel at M is driven to grind work carried on the table i2.

Located adjacent the machine, and preferably to the rear ti'iereer, is the filtering system of this invention generally indicated by the reference numeral [6. Preferably, the unit forms a portion of the bed of the machine in order to elin iinate as much of the external bulk as possible but for the sake of clarity,'the filtering mechanism has been illustrated the diawing s as an entirely separate apparatus.

The filtering system supplies cooling or lubri- V eating fluid through a flexible conduit 18 to a nozzle 20 adjacent the wheel M so that the fluid can be sprayed directlyon the wheel and workpiece at their point of 'contact.The fluid so sprayed on the wheel anclwork drains onto the table l2 and thence into a passage in the bed which terminates in a discharge conduit 22 that retur'risthe u's'ed fluid to the filtering system.

Referring to Figures 2, 3 and 4, the filtering system will be seen to comprise a pair of sumps, tanks or reservoirs 24 and 26within which are suspended the filterin bags 28 and so respectively. The bags are preferably provided with a ring as at 32 around their upper, open ends which rests on a ledge '34 fixedly attached to the tank. The structure, 1. e., partition 36, extends to the tank walls and divides *it into upper and lower 'aaits so that fluid passed into either of the tanks at the top will be directed into the filter bag therein. Preferably, and for a reason to become more apparent hereinafter, the -ledge 34 is suspendeairem the partitions 3'6 by a-s'lee've 3 8 hav -in g a plurality of overflow apertures 40 therein. The filtering bags are 'a fabric of any suitable material and permit relatively free flow of fluid theretl'irough while retaining'substantially all of tliepartlcula'te foreign material within-the bag.

The fluid to be filtered enters the tank 124 from tlie'c'on'duit "22 above thebag 28 and pours into the filter bag 28. The fiuid pa-sses through this bag and collects in the space between the bagand the tank. The fluid level in the tank around the bag 28 gradually rises -unti1 it overflows into the upper part of the tank 26 by meansof the passage 42 (Figures 2 and 4) extending between the tanks. This overflow, it will be noted, s'pills into the open upper end of bag '30. It will be noted that -the lowermost portion of the passage 7" '42 is somewhat below the top of the primary filter bag 28 so that normally there is a substantially greater head on the fluid int-he bag 28 than in the lower part of the tank 24 before thebag will be filled to overflowing.

Th fluid that "pours into the secondary filtering bag passes through the said baganol collects in the lower part of tank 26 in the space around the bag 30. This fluid rises in the tank until it reaches a level that will permit itto pass through the aperture 44 and into the chamber 46. The chamber 46 is between the tanks 24am *26 andis best seen in Figures '3and6; Within the chamber 46'is'a pump' 48 which is driven by a motor 50 which is preferably vertically mounted and has itsdrive "shaft extending downwardly into engagement with the drive shaft of said pump. The pump draws-'fluid'from'thechamber 46 and discharges the said fluidintoa conduit 52 which extends upwardly and is connected with the aforementioned flexible conduit l8 which leads to the spray nozzle 28 adjacentthe grinding wheel. The circulatory system described above consists of the main flow channel for the fluid to be filtered. It will be noted that this fluid flows by gravity through a primary filtering element, then passesto a secondary filtering element and news therethio'ugh by gravity, and finally is pi'ekd up by the circulating pump.

The area of each of the primary and secondary filtering elementsis large and the area of each of the primary and secondary reservoirs is also relatively large so that the flow of fluidthrough the filteringsystem. is relatively slow. This gives the particulate material carried by the fluid time 'to -settle 'out' so that any foreign matter passed throughthe bags is largely collected as a sludge in'the primary and secondary reservoirs.

Referring to Figure 3, it will be noted that the primary reservoir 24 has a sloping bottom plate 54 while the "secondary reservoir also .has a bottom plate 56 which is inclined downwardly toward the center'of the filtering apparatus. Between the filtering reservoirs and beneath the chamber 46 is another chamber 58 which is communicable with the reservoirs '24 and "26 7 through the :apertures "60 and "62 respectively which open'in-to the-said tanks at their lowest points. Each of the apertures Gil-and 62 is adapt ed for being closed by a resilient valve member 64 movable into engagement therewith by a lever extending upwardly through the chambers 58 and 46 and into an-open well or recess 66 between the tanks 24 and 26., This well may also'house =the=m0tor50 ifdesired. I V

The valve actuating levers, indicated at 68 engage the rods 'H) passing through the said valve members and are 's'ealed in their passage through the bottom Wall 12ofthe chamber 46 by the' rube her-like blocks 14. These blocks are best-seen in Figure '9 and 'it will be apparent that they can eifect an adequate seal without hindering the angular movement 'of the rods 68. In Figure '8, it will -be -noted that the rods '18 are passed through blocks '16 secured'to the' botto'in walls of the filtering reservoirs so that theresilient valve members 64 are guided "to and from their seated position.

-In -Figure'2, --it will be-seen that each of the rods 68'extends through the upper wall 18 ofthe chamber 46 through a slot 88 which has one end offset substantially 'at right angles so that the rods may each be-locked in the position in which diffusing the tank 90 has suspended therein a relatively coarse fabric sleeve 92. The opening of the sleeve 92 is covered by a perforated plate 94. This assembly is suspended from a plate 96 which is centrally apertured to receive the end of the flexible conduit 88. Fluid delivered through the conduit 28 is discharged onto the plate or tray 94 and passes therethrough into the sleeve 92 and is filtered partly through the said bag into the tank 90. More specifically, the action of the sleeve 92 is to diffuse and slow down the travel of the fluid so that the foreign particles entrained therein have the maximum opportunity to settle out as a concentrated sludge indicated by the stippling at 98 in Figure 5. The tank 90 is provided with a pair of conduits I00 which pass through the tank and which have the openings I02 therein through which the filtered fluid in the tank overflows. The conduits I00 also serve the purpose of supporting the plate 96 and terminate at their open ends in an elbow or bent portion I04 which opens into the primary filtering bag 28. The primary filtering tank 24 is preferably closed with a removable lid I06 which is apertured as at I08 to receive the elbows I04. The apertures I08 and the elbows I04 provides means of suspending the tank 90 on the filter. The tank may thus be removed quite easily for removing the sludge therefrom.

When it is desired to clean the sludge tank 90, both of the apertures 60 and 62 are closed by their valve members so that the chamber 58 becomes tightly closed. Thereafter, the pump 8'2 will withdraw fluid from the chamber 58 and create a suction therein which also stands in the conduit IIO. Conduit IIO extends upwardly substantially parallel with the conduit 84 and has its lower end opening into the chamber 58. The upper end of the conduit I I0 has a shut-off valve II2 from which extends a fitting or pipe nipple I I4. When the tank 90 is to be cleaned, the plate 96 and the bag 92 carried thereby are lifted from the said tank and are placed in the upper part of the primary filtering tank 24. A flexible conduit or hose is then attached to the nipple H4 at one end and the other end placed in the tank 90.

Then, when the valve I I2 is opened the suction in the chamber 58 is effective to draw the fluid from the tank 90 and to discharge it through the conduits 84 and 08 into the bag 92 whence the fluid passes into the upper part of tank 24 and to the primary filtering bag 28. When th fluid has been drawn off from the tank 90, the tank may be lifted from the machine and the sludge removed therefrom. The cleaning of the sludge tank is now completed and it may be reassembled and placed into operation.

It will be noted that any of the bags of the several filtering units can readily be removed from its reservoir for cleaning or replacement.

Thus, if desired, the bags may be cleaned or replaced daily and the sludge tank cleaned out as often as is necessary. This insures a continuous supply of clean cooling or lubricating fluid at all times.

Should the amount of fluid being circulated through the system exceed the capacity of any of the filtering bags, the excess fluid will overflow through the apertures 40 in the bag suspending sleeves so that there is no discontinuance of the operation of the circulatory system.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions and, accordingly,

it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

I claim:

1. In a filter; a pair of units each comprising a tank having a transverse apertured partition therein, the partition of the first tank having a greater elevation than the partition of the second tank; a filter bag in each tank suspended at its open end from the partition at the periphery of the aperture therein; a conduit connecting one of the tanks exteriorly of its bag and beneath the partition therein with the interior of the bag of the other of the tanks above the partition therein; a pump having its inlet connected with said other tank exteriorly of the bag and beneath the partition therein and adapted for discharging to a work station; a fluid inlet discharging from a work station into said first tank above the partition therein; a sump and means for selectively connecting and disconnecting said sump with the lowermost part of at least one of said tanks; a third tank having a filtering element therein; and conduit means connected to convey fluid from the sump through said third filtering element and into said first tank above the partition therein. 7

2. In a filter; primary and secondary units each comprising a tank having an apertured transverse partition therein, the partition of the first tank having a greater elevation than the partition of the second tank; a filter bag in each tank suspended at its open end from the partition at the periphery of the aperture therein, said partitions and filter bags cooperating to divide said tanks into upper inlet and lower outlet compartments; means connecting the upper part of the primary outlet compartment with the secondary inlet compartment; a pump connected to the upper part of the secondary outlet compartment to draw fluid therefrom and to discharge it to a work station; a fluid inlet connection to the inlet compartment of the primary unit; a third filtering unit having an inlet and outlet; conduit means connecting the inlet of said unit with the bottom of the tank of said primary element and the outlet of said third unit with the inlet compartment of said primary element, said third filtering unit comprising a tank of substantially greater area than said conduit means and a vertical foraminous barrier arranged between the inlet and outlet whereby fluid flowing from said conduit into said tank will slow down and diffuse through said barrier while th particulate matter entrained therein will have a tendency to be precipitated to the bottom of the tank, and pumping means for forcing fluid through said conduit means to the inlet of said third unit.

3. In a filtering system, a pair of tanks, transverse partitions in the upper parts of said tanks at different levels thereof, a channel extending substantially horizontally between said tanks from beneath the higher of said partitions to above the lower thereof, said partitions having a large central aperture and an open filtering bag in each tank suspended at its open end from each partition at the periphery of the aperture therein, said partitions and bags thereby dividing each tank into upper and lower compartments, a sump connected with the upper part of the lower compartment of the tank having the lower partition, a pump having its inlet connected with said sump and operable to draw fluid therefrom and for conveying it to a work station, an inlet connection in the upper compartment of the tank having the 9 i tray over the upper end of said element and into which said pump discharges, and overflow means connecting the upper part of said tank around said sleeve with the upper compartment of one of said reservoirs.

9. In combination with a filter tank having an apertured transverse partition and a filter bag suspended at its open end from the partition at the periphery thereof separating the tank into an inlet section and a settling chamber, a tank open at the top, a relatively coarse perforated sleeve vertically arranged in said tank, a perforated plate at the upper end of said sleeve and through which fluid passes to the interior of said sleeve, means supporting said sleeve and plate, an overflow in the upper part of said tank outside said sleeve for discharging fluid from the space between said sleeve and said tank, and pumping and conduit means to convey fluid and sludge from said settling chamber to said plate, whereby the fluid passes through the plate into the sleeve, diffuses outwardly through the walls of said sleeve and the particulate material entrained therein has a tendency to be precipitated to the bottom of the tank.

10. In combination with a filter tank having an apertured transverse partition and a filter bag suspended at its open end from the partition at the periphery thereof separating the tank into an inlet section and a settling chamber; means for treating fluid and sludge from said chamber and to efiect a substantial separation of fluid from the said sludge and to return fluid to the filter, said means comprising: a tank, a relatively coarse perforated sleeve vertically suspended in said tank, and open both top and bottom, a perforated plate across the upper end of the sleeve through which fluid and sludge passes to said sleeve, overflow conduits extending into said tank outside said sleeve adjacent the upper end of the sleeve to convey fluid from the space between said sleeve and said tank to the filter, and means supporting said plate and sleeve on said conduits.

11. In a filter; a primary settling reservoir having a transverse apertured partition and a primary filter bag detachably suspended from the periphery of the aperture in the partition; a secondary settling reservoir also having an apertured partition set at a lower elevation than the primary reservoir partition, and a secondary filtering bag detachably suspended from the periphery of the aperture of the said partition; channel means connected from beneath the partition in the primary reservoir to above the partition in the secondary reservoir; a closed sump connected with said secondary reservoir beneath the partition therein to receive filtered fluid therefrom; pumping means for forcing fluid from said sump to a work station from which the fluid returns to the space above the partition in said primary reservoir; a chamber between said reservoirs at the bottom thereof; valve means operable selectively to connect and to disconnect said chamber with the lowermost partitions of said reservoirs or for closing said chamber; a pump having its inlet opening into said chamber and an outlet; a tank; a relatively coarse perforated sleeve vertically suspended in said tank and open both top and bottom; a flexible conduit connecting said pump outlet with the upper open end of said sleeve; overflow channel means connecting the upper part of said tank outside said sleeve with the said primary reservoir above the partition therein; and an auxiliary conduit opening into said chamber and having a flexible portion whereby, upon actuating said valves to close said chamber, placing the end of said conduit in said tank and actuating said pump, the fluid may be drawn from said tank preparatory to cleaning the sludge therefrom.

12. In a filter; a plurality of serially connected filtering units each having a, settling reservoir; a, closed sump connected to receive sludge and fluid from said reservoirs; a diffusing chamber adapted with an inlet to receive sludge and fluid from said sump and having an outlet, said chamber including a foraminous barrier between said inlet and outlet to direct the sludge toward the bottom of the chamber while substantially clean fluid will pass to the said outlet; a pump having its inlet in communication with said sump; a plurality of valve means selectively operable to connect and to disconnect said sump with said reservoirs or with said chamber; and passage means for selectively connecting the outlet of said pump with the inlet of said chamber or with the inlet of said filter.

13. In a filter; a pair of units each comprising a tank having a transverse apertured partition therein, the partition of the first tank having a greater elevation than the partition of the second tank; a filter bag in each tank suspended at its open end from the partition at the periphery of the aperture therein; a conduit connecting one of the tanks exteriorly of its bag and beneath the partition therein with the interior of the bag of the other of the tanks above the partition therein; a pump having its inlet connected with said other tank exteriorly of the bag and beneath the partition therein and adapted for discharging to a work station; a fluid inlet discharging from a Work station into said first tank above the partition therein; a sump and valve means for selectively connecting and disconnecting said sump with the lowermost part of at least one of said tanks; a third tank having a filtering element therein, and a second pump having conduit means connected to convey fluid from the sump through said third filtering element and into said first tank above the partition therein.

OTTO M. SUMMERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 681,477 Franke Aug. 2'7, 1901 985,961 Ten Winkel Mar. '7, 1911 1,081,082 Alden Dec. 9, 1913 1,271,925 Moore July 9, 1918 1,462,048 Richards July 1'7, 1923 1,936,315 Tillman Nov. 21, 1933 1,959,623 Gordon May 22, 1934 2,044,096 Moran July 16, 1936 2,364,418 Barker Dec. 5, 1944 2,396,927 Nelson et al. Mar. 19, 1946

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