US2095485A - Device for metering liquids - Google Patents

Description

-0Ct. 12, 1937; s, BASSETT 2,095,485

DEVICE FOR METERING LIQU IDS Filed March 5, 195? INVENTOR BY W Patented oot. 12, 1937 UNITED STATES :PATENT OFFICE DEVICE FORMETERING LIQUIDS V Robert S...Bassett,'Buffal0, N. Y. Application March 5, 1937,;Serial Nb. 129,236

' '7 Claims. (C1."73-'-198) -My invention relates 'to a device forflmetering :liquids which are flowing at such a low rate that {they cannot be ordinarily metered bysimple and inexpensive mechanical means such as the dis- -placement type liquid meters which are now-com- '-mercially available. Among the. best-of such s meters is the familiar nutating disc type? liquid meter which if carefully constructed will accurately measure flows of liquids such-as fuel oil .atflowshavinga' rate as low as three gallons per hour or as high as' twenty gallons per minute. Theobject' of my invention particularly is to measure flows of liquid-which -must=be discharged from the measuring device slowly and uniformly at flow rateswhich-willordinarily be between one-half and two and one-half gallonsper hour. -*Suchflows donot developenoughpower to continuously overcome the running friction of displacement type liquid meters. This friction loss, however, can be minimized if only operative duringa'part of the flow cycle. fA particular applicationof mydevice is'to themeasurement of fuel oil consumed 'by small: oil burners used especiallyj for house heating purposes The supply of oil to theoil burner when burning must "be steady and constant and is usuallyat a flow'of approx-i mately two gallons per hour. My device is especially suited for the metering of such'slowjflowing liquidbutits maximum capacity issubstanjtially. that of the liquid meter which is used as a part of the device .as shown in the; illustrations and the description. v 7

Another object. of my invention is to .provide safety devices so thata fire hazard is eliminated. .Metering devices, of this type are usually used adjacent to a flame .and my invention provides against, oil overflowing into the surrounding space and also provides against igniting the oil through ,the vent opening, asimi'ght occur if. a. child was playing with matches and tried 'toput a lighted .match into, the vent opening-of my'device.

To illustrate. more. clearly the application of my invention I shall describe its particular use in connection with small oil-burners. i V

,"Figure ljis an. exterior side view of my device asinstalled with .a' typicalhouse heating furnace Jfitted with a fuel oil burner. 1

A 'Figure'Z is a vertical sectional-view through the accumulator or reservoirltank and-shows the location of theopenings andi thelinterior mechanism.

Figure 3 is a vertical sectional view-through the venting valve. 7 v 7 "Referring, to thedrawingin detail, [is a tank servingas the oil supply container. .2 is the shutoiT valve .on the discharge linefrom supply container l. 3.-is..a trap strainer of the usual-type which. is requiredwon such installations. to remove ,impurities from the oil before itenters' the other apparatus. 4 is any suitaple liquid meterand is ;.-shown asthe' familiar displacement type mutating disc liquid meter. 15 is the reservoir tank with yinlet'ie outletlz-aand air outlet 8. 9 is a venting 'valve. connected toair outlet 8 and allowing the passage. of=air but stopping the passage of liquid as explained later in this specification. shut-oif valve on the outlet line from reservoir lllisa Reservoir tank 5 as shown in Figure 2 has in combination with it asnap action valve controlling the flow through inlet-6 and which is shown operated by-means of afloat within thetank, which will open wide the valve. when the level withinthe tank is at a low point and close the valve with a snap action when the level within the tarik-isat a much higher point. A snap ac- .'tion float controlled valve can be constructed in "many ways and I am not limiting the construction to that shown in the drawing which is only 1 one of a number of different types which can be used; The'essential'feature of the-snap ac tion valve is that it is suddenly-opened wide when float I9 reaches its lowest 'point'of travel and-'is similarly closed whenffloat l9 reaches its uppermost point of travel. These relative positions of the valveand the float are features of my invention together with the location of the valve on the flowline ahead of the tank inlet.

In Figure 2 as illustrated, the valve comprises -replaceableseat Zlhvalve ba1lj2l, spring'seat 22,

and spring 23. Valve ball 2| is normally held against seat .20 by spring-23 which preferably is V of the spiral compression'typeand confined between ball 2| and spring seat 22 to .keep the, valve in closed .position. This valve as shown opens Q against the pressure which aids in, holding it closed. Valvestem 24 is suitably guided for an;

ordinary pushing contact against .the side of ball .2 l so that the valve may be opened when stem 24 -is pressed againstball2l pushing it awaylfrom seat 20. The valve is closed when stem 24 moves away from ball 2| allowing it to .bepushed by spring .23 to its normal closed position against ertzii, fulcrum pin 28 andspring 29 which is shown as of the tension type, though a similarly acting linkage is often constructed, where the space is limited,'with a compression type spring. It-is not. necessary to .describein detail the snap action of the valve. as it isof the usual type, ex-

.cept to reiterate that ball-2| issuddenly pushed from seat'20, when float l5 approaches thebottom of reservoir tank 5. Similarly, ball 2| is suddenly moved tight against seat to close inlet passage 6, when float l9 approaches the upper portion of reservoir tank 5. While the term snap action is used to describe the valve, any quick opening and quick closing valve may be used, provided that the throttling of the flow, when the valve opens and closes, is for no appreciable length of time.

Reservoir tank 5 as shown in the drawing is constructed with its enclosing walls made from an ordinary snap top paint can of tinned steel. This construction is very low in cost as such cans are a standardized article produced in large quantities and readily purchased in the open market for adaptation as in my drawing. The member containing inlet passage 6, outlet passage and air outlet 8 and assembled with the valve itself will be numbered as valve body which can be made of brass and soldered into an opening in the wall of tinned steel reservoir tank 5. Tank cover 3| allows the servicing of float l9 and other parts inside of tank 5. In the drawing and in actual practice tank cover 3! is an ordinary snap type or beaded friction paint can top which is liquid-tight but at the same time very low in cost and perfectly serves its purpose of allowing occasional inspection of the parts inside of tank 5 and of, at other times, keeping the enclosure of tank 5 in a liquid-tight manner.

My drawing also illustrates in a reservoir tank of this type the use of a readily accessible snap action or quick acting valve which opens against the fiow, as this construction not only prevents excess pressure from opening the valve, but it also makes seat 20 and valve ball 2| readily accessible for inspection and repair without disturbing other parts of tank 5 surrounding the float itself. The action of my device is relatively simple, as is necessary for continuous troublefree operation of such an attachment, where the operation of the furnace must at no time be interfered with.

The oil in reservoir tank 5 runs out slowly to burner II, as required for combustion in the burner. When there is only a small quantity of oil left within reservoir tank 5, float 9 opens the valve, allowing a sudden inrush of oil from container I, through meter 4. This flow of oil to fill reservoir tank 5, is at a rate far in excess of that of the flow to the burner itself. Under ordinary installation conditions with the bottom of container elevated a couple of feet above reservoir tank 5, thisflow is around sixty gallons per hour which is more than ample to operate meter 4 at a speed at which it will measure very accurately.

In passing one gallon of oil through the system the meter is operated for approximately one minute only, while it will take approximately thirty minutes for one gallon of oil to be used by the oil burner. In this way the friction of the meter must be overcome during only onethirtieth of the time that the burner is requiring oil, so that the power to operate the meter is thirty times that which it would be if the energy from the movement downward of one gallon of oil for a couple of feet was distributed over the entire period of thirty minutes. .An inexpensive meter of the commercial type, such as would be used on this installation, requires a fractional number of foot pounds energy per minute to operate it, almost irrespective of the rate of flow through the meter, up to a couple of gallons per minute. To have such power available to operate the meter, it is necessary either to cut down the time per gallon of liquid passed, during which the meter operates or to introduce an additional source of power such as an electric motor, which would be connected to the meter to overcome its running friction. Such electrical power devices, however, have not proved satisfactory in actual service.

Reservoir tank 5, is fitted with air outlet 8, which releases air to allow the entrance of the oil to fill the tank, as it passes in through inlet 6. Such an air outlet is of conventional construction and is required if the walls of the tank are fixed in dimension.

The essential elements of my device are a storage reservoir on the outlet line from the meter and between the meter and the liquid consuming means, a quick acting valve controlling an intermittent flow to the reservoir and located between the reservoir and liquid supply means, together with means to open said valve when the supp-1y of liquid within said reservoir approaches its minimum. My invention is much simpler and more practical than other devices used since my discovery thereof and which use a differential between two liquid pressures to operate the valve, the control chamber being always full of liquid. The means to open said valve in my invention also acts as means to close said valve when the supply of liquid within said reservoir approaches its maximum.

Figure 3 shows the details of venting valve 9 which include many novel features which make the above installation safe from fire hazard from nearby flames. 9 are included in my claims as they act together with all other parts of the mechanism in such a way as to make the entire assembly a practicable and safe device. 32 is the inlet opening and 33 the outlet opening. Across outlet opening 33 is placed a screen 34 which is made of metal with fine openings to act in the well-known manner as a flame arrester to prevent flames from passing downward through it to the interior of venting valve 9 to ignite the fuel within tank or chamber 5. This device works on the well-known principle of the miners safety lamp. The use of screen 34 is novel in that it eliminates the necessity of piping outlet opening 33 back to container I as has always been necessary in the past to prevent fire hazard. My invention greatly cuts down the installed cost of the metering device. 35 is shown as a cork ball which acts as a float as well as a closure means. The construction is not limited to the exact construction shown but may be any float device which controls the two openings of venting valve 9. Ball These members of venting valve 35 rests loosely on seat 36 to prevent the un-- necessary escape of oil fumes out of tank 5 through air outlet 8. This fire hazard protection is a novel feature and the retention of dangerous fumes within tank 5 is a feature not found on any other similar metering device. The weight of ball 35, relative to the area of the opening in seat 36, is designed with consideration for the values of the strength of spring 23, area of seat 20, and diameter of ball 2| so that the slight back pressure or pressure above atmospheric pressure caused to exist within tank 5 because of ball 35 will not interfere with the action of valve ball 2| as a closure means for inlet opening 6.

Venting valve 9 also serves another very important purpose. Valve ball 2| under abnormal conditions might fail to close completely when ether-level; ofxthe1,:liquid within tank'zirreacheszits 1 upper limit. This might 1 be caused .::by: dirt liberooming: lodged between r valve .ball ,12 l andoseat n2U- or byfl-floatfilii becominggfull of rliquidazeither through i-leakage -;or by jcollapse. PSuch cong tingencies-mustvbe; :provided; forxtovmake the meztering-adevice free: from} fire "hazard. ;-As ';the .in-

terior :;parts.-.of tanka5 ;may iffail: to operate: normally and become 5 inoperative, I have arprovided ria safety device entirely outside of tankBflto: prevent-liquid withintankifi that passes" out through air goutlet 8*from finding. its way .to ::the1atmos- 3 phere outside. Venting =-valve 119,-.rWhiCh controls can: outlet :8, :not= only retards :.-the- --escapeof "BX- icplosive. fumesduring the normalgoperationof the metering device,. but; it also acts: as an automatic shut-off when tank"5x-with its valve mechanism fails to operate satisfactorily; Liquid passing up into venting valve 9 oausesjccork' ball torise 320 .ing'33.

upward to'a'position where it blocks outlet open Upperrseat i3!- is 'provided, -agai-nst which cork ball 35 wedges,-to::act as .aazsafety. device to prevent overflowrofrthe liquid. :Ihave-provided "for a safety .device entirely exterior to tank (SO that the safetyzdevicezawhich is shown as venting valve 9 is: replaceable as .a separate unitand can :be readily inspected and removed for testing "without in any my opening up -tank ":5,

:a :novel and valuable ffeature- -:When' 'tank -5 4:30,

within tank fi, which; however,- is notqsuificient fills, venting valve 9 creates 'awslightcair pressure *to- .preventtank 5 from fill-inggupato the desired .upper'limit. i Wheri ball 21 movesfback: against :seat 28 closing ;.inlet 56, :this air "under slight :pressure; aids: in: forcingrthe liquid: within tank -5 out through outlet fopening '1. i :Corkba1l' 35,"however, seatswloosely' on meat-F36 so-that. asmall amount of airxcan beflrawmdownthrough ventringfva'l-ve fitintoitankzi as maytberequiredto al- .40

lowthe liquidwithin tank 5'to flow out'toits lower limitroflevel. =-Whi1e .therxpressure Within tanklfi may be slightlyr'below atmospheric during the .latter cof this emptying :process,

.the'flow .of rtheiliquid." from :tank 5zis' in no way .stopped. Conversely, "corkaballrfi acting as a .back 1 pressure valve :maintains an seven ifiowoof ing thefilling :operation and .t-endsritonereate 1a veryslight 'backspressure .on the-outlet of liquid 'ducted by the": inventor.

meter i4 and thereby causes'a morersatisfactory operation and uniform measurementithan if: the flow out of liquid: meter 4 :wasn'otr held iback; in any way. All ofrthese points: haveprovemthemselves to'be of greattvalue in :actual testscon- These features are incorporated in the claims "with special :reference to the fire hazard prevention value.

Having thus describedcmyEinventiongwhatiI claim fOI' LEttEI'S Patent is: v

1. The combination with liquid fuel metering apparatus comprising-aesupply tankgfuel'directing means including a conduit for conveying-the fuel from said tank to a point of' use, and1 a*flow meter interposed in the conduit'for measuring and indicating the quantity l of "fuel conveyed therethrough; of a ;'chamber interposed. in said conduit between the meter and the point of :use,

andhaving afu'el inlet port, a valve controlling "the entrance of fuel-into;said chamber'hthrough gsaid inletgport', a float'in said :c'ha'mbenomeans for causing said'valve to 'be movedto closed and open positions by saidf float only whenrsaid "float is moved "through a relatively wide range of movement, and an air vent from said chamber; and a venting valve attached to said air vent for maintaining: a;pressure inzsaidrchamber, slightly above atmospheric pressure whensaid'ivalvecom ritrollingtthe ientrance of" fuel into said chamber through .said inlet- -port is open,-and:having'a 'gravityeoperated-closuremember, and a seat co- :actingrwithrsaid: closure member to substantially close: said "valve to: retard the escapetof-explosive fumes outiithrough said zventing valve but to open slightly :asrequired'to allow the escape .of air "when :said 1 chamber inlet DOI'tJVZtlVQjS. open and a-said :chamber: isrffilling-with liquid fuel, r substan- ::tially as-zan-dffor thepurpose described. r

. 2; The combination withliquid: fuel 'm'eterin apparatus comprising :a supply, tank,'fuel directmgr-means .including;a' conduit for :conveying :the

. fuelxf-rom; said-, tanl ,to"-a point r of .use, and a flow wmeterrinterposed;inthe conduit for measuring and indicating ithe quantitysof i fuel conveyed lthe'rethrough; of .a-chamber interposed .in said .conduitrbetweenithe.meter.and the point of use,

-andfhavingcafuel outlet port fromsaid. chamber :continuouslycopen .to said .point of use'whereby fuel. may be withdrawn'from'said chamber at any -time, =a:fue1 inletiport, :a valve controlling the zentrance: of fuel: into; said chamber through said :wthroughrsaidinlet;port is open, andhavinga -1.:gravityeoperated closuremember, and a seat co-- :zactingtwithtsaid :closure member to substantially cc1osesaid-valve to retard the escape of explosive fumes out through'saidventing valve :butto open islightlygas required to allow .the escapehof air when said chamber; inlet port valve :isnopenand said-chamber. is filling'with: liquid fuel, substantiallynas, and for-the "purpose described.

3..The combination .withtliquid fuel metering pp r "comprisin pp y tank, fuel :direct- :ingmea-nsyincluding .a conduit for conveying the ffuel-fromsaid: tank: to a point of use, and=a flow :umeter'interposed in,the conduit for measuring .iandniridicatingithe ..q uantity of fuel conveyed :therethrough'; ;of;:a chamber interposed in-said' xconduitsbetweentthemeterand the point. of use, :and. having ra fuel outlet-{port fromzzsaid cham- =rber;:contin-uously;open to said point oftusewhreby fuel :may be withdrawntfrom said: chamber at .an-yzitimena. fuel inlet'rport, a=valveincsaid :inlet :port sand controlling the entrance :of fuel 7 into said :chamber, :a float in said chamber for coni1tI'Q11lHg?S3,id valve, toggle mechanism connecting saidifloatloperatively.with-said valve to snapsaid valve to closed -or open position only at two predetermined positions of'said float within said eha-mibe wand an-air vent from said chamber; and a"venting valve"attached'to said air vent for maintaining -a pressure in said chamber slightly aboveatmospheric pressurewhen said valve "controlling the entrance of fuel into said ",chamberlthrough said inlet port .is open, and having a gravity-operated closure member, and

,-.aseat ,.co=acti1;1g twit-husaid closure member to .substantiallyclcsesaid valve to retard the escape @of explosive fumes-out .through said venting avalve :but to -.openeslightly as required -to allow the escapeof air when said chamber inlet port r valve is open and said chamber is filling it liquid fuel, substantially as and for the purpose described.

4. The combination with liquid fuel metering apparatus comprising a supply tank, fuel directing means including a conduit for conveying the fuel from said tank to a point of use, and a flow meter interposed in the conduit for measuring and indicating the quantity of fuel conveyed therethrough; of a chamber interposed in said conduit between the meter and the point of use, and having a fuel outlet port from said chamber continuously open to said point of use whereby fuel may be withdrawn from said chamber at any time, a fuel inlet port, a valve controlling the entrance of fuel into said chamber through said inlet port, a float in said chamber, means for causing said valve to be moved to closed and open positions by said float only when said float is moved through a relatively wide range of movement, and an air vent from said chamber; and a venting valve with inlet and outlet openings and attached to said air vent for maintaining a pressure in said chamber slightly above atmospheric pressure when said valve controlling the entrance of fuel into said chamber through said inlet port is open, and having outside of said chamber float means for closing said venting valve outlet opening to prevent the escape of liquid fuel from said venting valve when said fuel escapes from said chamber into said venting valve, substantially as and for the purpose described.

5. The combination with liquid fuel metering apparatus comprising a supply tank, fuel directing means including a conduit for conveying the fuel from said tank to a point of use, and a flow meter interposed in the conduit for measuring and indicating the quantity of fuel conveyed therethrough; of a chamber interposed in said conduit between the meter and the point of use, and comprising a fuel outlet port from said chamber open to said point of use whereby fuel may be withdrawn from said chamber, a fuel inlet port, a valve controlling the entrance of fuel into said chamber through said inlet port, a float in said chamber, means for causing said valve to be moved to closed and open positions by said float only when said float is moved through a relatively wide range of movement, and an air vent from said chamber; and a venting valve with inlet and outlet openings and attached to said air vent for maintaining a pressure in said chamber slightly above atmospheric pressure when said valve controlling the entrance of fuel into said chamber through said inlet port is open, and comprising, outside of said chamber, float means for closing said venting valve outlet opening to prevent the escape of liquid fuel from said venting valve when said fuel escapes from said chamber into said venting valve, said float means also substantially closing said venting valve inlet opening to retard the escape of explosive fumes out through said venting valve but in such a manner as to open slightly as required under slight air pressure to allow the escape of air from said chamber through said chamber air vent when said chamber is filling with liquid fuel, substantially as and for the purpose described.

6. The combination with liquid fuel metering apparatus comprising a supply tank, fuel directing means including a conduit for conveying the fuel from said tank to a point of use, and a flow meter interposed in the conduit for measuring and indicating the quantity of fuel conveyed therethrough; of a chamber interposed in said conduit between the meter and the point of use, and comprising a fuel outlet port from said chamber open to said point of use whereby fuel may be withdrawn from said chamber, a fuel inlet port, a valve controlling the entrance of fuel into said chamber through said inlet port, a float in said chamber, means for causing said valve to be moved to closed and open positions by said float only when said float is moved through a relatively wide range of movement, and an air vent from said chamber; a venting valve with'inlet and outlet openings and attached to said air vent for maintaining a pressure in said chamber slightly above atmospheric pressure when said valve controlling the entrance of fuel into said chamber through said inlet port is open, and comprising, outside of said chamber, float means for closing said venting valve outlet opening to prevent the escape of liquid fuel from said venting valve when said fuel escapes from said chamber into said venting valve, said float means also substantially closing said venting valve inlet opening to retard the escape of explosive fumes out through said venting valve but in such a manner as to open slightly as required under slight air pressure to allow the escape of air from said chamber through said chamber air vent when said chamber is filling with liquid fuel; and a flame arresting screen with fine openings at said venting valve outlet opening to prevent the entrance of flame into said venting valve when filling with explosive fumes, substantially as and for the purpose described.

'7. The combination with liquid fuel metering apparatus comprising a supply tank, fuel directing means including a conduit for conveying the fuel from said tank to a point of use, and a flow meter interposed in the conduit for measuring and indicating the quantity of fuel conveyed therethrough; of a chamber interposed in said conduit between the meter and the point of use, and comprising a fuel outlet port from said chamber open to said point of use whereby fuel may be withdrawn from said chamber, a fuel inlet port, a ball spring-loaded check valve at said inlet port and controlling the entrance of fuel into said chamber, a float in said chamber for controlling said valve, toggle mechanism connecting said float operatively to said valve through said inlet port to open and close said valve only at two predetermined positions of said float within said chamber, and an air vent from said chamber; and a venting valve attached to said air vent for maintaining a pressure in said chamber slightly above atmospheric pressure when said valve controlling the entrance of fuel into said chamber through said inlet port is open, and comprising a light-weight gravityoperated closure member, and a seat co-acting with said closure member to substantially close said valve to retard the escape of explosive fumes out through said venting valve but to open slightly as required to allow the escape of air when said chamber inlet port valve is open and said chamber is: filling with liquid fuel; said chamber also comprising an inspection opening above the normal level of the liquid within said chamber and a readily removable cover for said opening, substantially as and for the purpose described.

ROBERT S. BASSETT.

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