CA2090786A1 - Additive blending controller - Google Patents
Additive blending controllerInfo
- Publication number
- CA2090786A1 CA2090786A1 CA 2090786 CA2090786A CA2090786A1 CA 2090786 A1 CA2090786 A1 CA 2090786A1 CA 2090786 CA2090786 CA 2090786 CA 2090786 A CA2090786 A CA 2090786A CA 2090786 A1 CA2090786 A1 CA 2090786A1
- Authority
- CA
- Canada
- Prior art keywords
- additive
- volume
- main product
- controller
- predefined
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D11/00—Control of flow ratio
- G05D11/02—Controlling ratio of two or more flows of fluid or fluent material
- G05D11/13—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means
- G05D11/131—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components
- G05D11/132—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components by controlling the flow of the individual components
Abstract
ABSTRACT OF THE DISCLOSURE
A method for controlling an additive blending process includes determining the volume of main product and blending an amount of additive thereto to obtain a predefined ratio of additive to main product. The method includes the step of creating a non-volatile record of each significant event which occurs during blending operations and includes an extensive error checking and safety regime.
A controller for accomplishing this method includes the ability to blend multiple additives simultaneously and with different types of blending systems such as piston injectors and streaming. The controller monitors status signals from the system and removes enabling signals from various components to effect a safe shut down in the event of an error condition being detected.
A method for controlling an additive blending process includes determining the volume of main product and blending an amount of additive thereto to obtain a predefined ratio of additive to main product. The method includes the step of creating a non-volatile record of each significant event which occurs during blending operations and includes an extensive error checking and safety regime.
A controller for accomplishing this method includes the ability to blend multiple additives simultaneously and with different types of blending systems such as piston injectors and streaming. The controller monitors status signals from the system and removes enabling signals from various components to effect a safe shut down in the event of an error condition being detected.
Description
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2 ~ ~ j3 rs 'l5 ADDITIVE BLENr)lNG CONTROLLER
., _ "' ~; FIELD OF 1HE INVENTION
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S The present invention rel~tes to additive blending systems ~pecifically, the present invention relates to a novel method of controlling an additive blending system and to a novel additive blending controller.
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`. BACKGROUND OF THE INVENTION
_ _ ''. 10 In many fields it is necessary to blend additives with a main base product ~1 ' to fiorm a desired finished product. Typically, such additives need to be added Ito the main base product in precise ratios to obtain the required properties in the finished `~ product. Blending additives at ratios other than a specified ratio is undesired, both `~ 15 because the finished product may not perforrn to s~cifications and ~ecause many additives are relatively expensive and it is uneconomic to waste additive by exceeding the required ratios.
~, j ~ Non-limiting e~amples of products which undergo additive blending include:
; ~1 20 gasoline and jet fuels; lubricants; paints; vaIious food products; fier~ ers; and pesticides.
~¦ Systems for controlling the blendillg o~ additives with a base product at required ra~ios are Icnowll. Such systems typically empl~y a flow meter which outputs " .~ .
a signal every time a pre~efined amount of main product ha~ passed through the flow ~`; 25 meter. In response to that signal, a pre~efined amount of an additive is blended into the main product.
Several difflrent types of blending systems are kn~wn, perhaps the most common type employing additive injectors which are piston injecto~. These systems , :.
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~' ', - 1 ~, 2 :, ~, inject a pre-determined amount of an additive on each stroke of the piston. In response ~ ~ to a signal from a main product flow meter, the piston injector is stroked to inject a pre-- ~ defined amount of additive.
-,' Another type of blending system is the block valve blending system. In this ~ system a solenoid operated on-off, or block, valve is connect~i to a pressurized supply - of additive. An additive flow meter is connected between the Iblock valve and the main product line and, in response to an 'inject' signal from a flow rneter in the main product line, the block valve is opened by a controller, allawing additi~re to flow through the - 10 additive line flow meter and into the main product line. The controller receives 3ignal5 froni the flow meter in the additive line and, when a signal corresponding to a pre-` defined desired amount of additive is received, the controller closes the block valve.
Each time the controller receives the inject signal from the flow meter in the main ~, product line the process is repeated.
. 15 Yet another type of blending system is injector streaming. In streaming - systems, a controller rnonitors the main product line to determine the rate of flow, i.e.
~ . number of gallons per minute, etc. A second flow meter in the additive line allows the - ~ controller to deterrnine the flow rate of the additive. The controller o~rates a variaUe ~; ~ 20 position valve to adju~t the ~low of additive into the main product line. Por ex~mple, if the desired ratio of additive to main product was 10 ounces of additive per each five gallons of main product and the main product is flowing at ~ gallons per minute, the controller opens the va iable additive valve un~l the additive line flow meter outputs a signal indicating a flaw rate of 80 ounces of additive per minute.
Con~ollers for each o~ the above-mentioned techniques are known and range i ~om hard-wired systems, wherein for example the main product flow meter produces a ; `.
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2~7~(i : -3-pulse which directly triiggers a piston injector, to more sophisticated systems such as that shown in U.S. Patent 5,118,008 to ~lliams.
-~' The ~Illiams reference shaws a microprocessor baseid controller which S receives signals from a main product flaw meter and operates a block valve to supply additive accordingly. The controller counts the pulses received from the additive flow meter and compares the count to a pre-defined value in its memory. When the count equals the pre-defined value, the controller completes the injection cycle by shutting the ; ~ additive valve.
`~` 10 However, problems and/or disadvantages e~ist with the prior art systems.
~'f Such systems typically are only able to control a single type of iniector, such as block ``~ injectors or piston injectors. Also, the prior art systems cannot control more than a ., 3, single additive injection. When blending a product which includes se~eral additives, . ~ 15 either multiple controllers are required to be employed, one for each additive, or the ~ product must be blended in several product runs, one run for each additive required.
; ;~ Further, such systems typically require a manual re-configuration of the system for each . .ished product to be blended, with the ratio of additive to main product being manually adjusted either physically, by changing the flaw meters, or electrically b~3r replacing the 20 pre-defined values stored in the controller.
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Perhaps even more disadvantageous is the fact tha~ only ~he most limited ~ .`!
; ~ error-checldng alld/o~ repor~ing capabilities are provided in ~he prior art system3. The lack of error checl~ng and reporting c~pabilides is inc~ ingly becoming of concern, ~:3 25 both to meet regulatory requirements and to ensure that produc~ e correctly and ` ~1 economically produced.
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`~ SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel method of :;~ controlling an additive blending system.
; 5 It is a further object of the present in~ention to provide a navel conkoller for an additive blending sys~em.
According to a first aspect of the present invention, there is provided a , 10 method of controlling a blending system process comprising the steps ofo ;i (i) defining a desired ratio of an additive to a main product;
~ ' (ii) providing a flow of main product;
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'~j (iii) measuring the volume of said main product flow;
~ ., '. (iv) adding a predefined amount of at least one additive to said measured main : ~ 15 product flaw to achieve saud desired ratio;
(v) creating a non-volatile record indicating the time, date, amount and type ofi~ additive added in step (iv); and : ;' (vi) repeating steps (iii) and (v) as necessary until the process is tersninated.
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;:~ 20 Preferably, the method alllows the simultaneous or sequential blending of more ehan or~ additive, if ~equin:d, and allaws for more than a single type of blending 3 OpeI'atiOIl to be employed. Also preferably, the method includes error-checking ~, capabilities to ensure proper flow rates and correct operation of the sys~m and further ~: ~emoves enabl~ signals and/or plwides inhibit signals ~o cease ~pera~on of the system ~:~ 25 once an error condition has been detec~ed. Also p~e~erably, the method includes the `.` production of a transaction r~cor~ of all significant operations conducted by the sys~em, . .
such transaction records being sufflciently detailed to sati~fy regulatory ~equi~ements.
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~' :, ` ~~ 5 According to another aspect of the present invention, there is provided a conkoller for an additive blending system to blend at least one additive to a main product at a predefined ratio, l~omprising:
;1 main product volume measurement means;
S program storage means;
non-volatile memory means;
~ at least one additive supply control means; and `-` processing means responsive to said main product volume measurement means and operating said additive supply control means to provide a volume of additive to said main i' 10 product volume to achieve said predefined ratio, said processi~ means creating a record in said non-volatile memory means including the date and time said additive vo~ume was pravided and the volume of additive provided.
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Preferably, the controller is easily configurable to control one or more types 15 of blending operations. Also, it is preferred that the controller be able to conduct at least two different additive blending operations at the same time, either sequentially or in parallel, and that the diffe~nt operations may be effected by different types of blending - ~ operations, such as block valve and streaming. Also pre~erably, the controller includes a non-volatile memory which allows the storage of pre~efined ratios and the additives ~0 for two or more finished prQducts.
`~'1 Also prefierably, the controller maintains a recor l in non-volatile memory ` ~ of transac~ons conduc~:d by the controller, including tot~ls of finished product, additives adde~ and time and date of the transactions. Also preferably, the controller includes 25 means to storei the operating characteristics of the equipment ~o which it is a~tached to .j `~; minimi~e 'dribble' or other process variation. Further, it is preifi~rred that the con~roller be provided with communications capabilities allowing remote access from authorized . ,~
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data communication devices such as microcomputers, etc. and that such remote access '!~ includes configuration and reporting functions. It is also preferred that lhe controller . ~ includes a simple to use and easily understood data-entry keypad and digital readout :`',' ; .
S E~RIEF DESCRIPTION OF THE l:~RAWINGS
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: ~. Preferred embodiments of the present invention will now be described, by way of example only, with reference to the attached figures wherein:
Figure 1 shows a block diagram of a blending system controller;
, 10 Figure 2 shovs a keyboard and display module for the controller of Figure l;
Figure 3 shows a schematic representation of input and output ports of the controller of Figure l;
Fi~ure 4 shows a schematic representation of a blending sysS~m emplaying the ' controller of Figure l;
` ' 15 Figure S shows a flow chart of the initialization steps of the controller in the system of ~;igure 4;
Figure 6 shows a flow chart of the blending operations of the system of Figure 4;
~:` Figure 7 shows a schematic represenhdon of another blending system employing the controller of Figure l;
, 20 Figure 8 shows a flow chart of the blending operations of the system of Figure 7;
Figu~ 9 shows a schematic representa~on o~ another blending system employing the controller of Pigure 1;
Figure 10 shaws a i~ow chart of the blending operatioa~s of ~he system of Figure7; and Figure 11 shaws a flow chart of an Emergen~y 5hut Dawn proced .
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DETAILED DESCRIPTION OF THE PREFERRE~ EMBODIMENT~
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1 Referring now to Figure 1, a block diagram of a blending system controller - ~ in accordance with the present invention is shown. The controller, indicated generally at 10, includes a processor unit 20, a keypad 24, a battery bac~ up Real l~lme Clock IC) 28, a program RQM memory 32, an RS485 communications port 36, a display . ~ 40, a non-volatile memory 44 and valious input and ou~tput (I/O) ports 48 as will be described in further detail below.
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The above-mentioned components of the controller are commonly a~ilable and the present invention is not particularly limited to particular devices. In the preferred . ~ embodiment, processor 20 is a Z-80 microprocessor and Real rlme Clock is a MK~48T08 device manufactured by SGS Thomson Microelectronics. Similarly, in the prefe~d - -~ embodiment, RS485 communications port 36 is a Z84C40 device also manufac~ured by - ~
;, 15 SGS Thomson Microelectronics. Program ROM 32 may be any suitable ROM, EPROM, EEPROM or similar device and non-volatile memory 44 may be battery backed-up static I CMOS RAM devices, or other devices as would be apparent to those of skill in the art.
`~1 Figure 2 shaws a pre~erred embodiment of k~ypad 24 and display 40. In this pre~erred embodiment, ~eypad 24 and display 40 are combined into a single ~;; inteBrated module which may be mounted in any conveniealt place on the injection system. Keypad 24 includes four momentary ontact switches, 50a through 50d, as will ` ` ~ be desenbed in more detail below, and display 40 includes a six-digit digital display 54 " ~ and three status indicators 58a through 58c. Digital Display 54 may be LCD or LED-based or any other suitable type of display as would occur to those of skill in the art and status indicators 58 may be LED, neon, ineandesceDt lamps, or any other suitable; indication means as also would occur to tho3e of skill in the art.
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Status indicator 58a, the COM indicator. Iights when commur~ications are ,'! occurling through RS485 port 36. Status indicator 58b, the ARMED indicator, lights ;~ when the controller is enabled and is ready to commence blending opeTations. Finally, status indicator 58c, the CY~LES indicator, lights each time a blending c;~cle .
S commences. These operations are described in more detail below.
I/O ports 48 may include many different types of input and output signals, as required for a particular system. The I/O ports of the prefierred embodiment, as shown in Figure 3, include two isolated DC Outputs 60, a four to twenty milliamp10 variable DC output 64, eight isolated AC Outputs 68, twelve Digital (ON-OFF) Inputs 72, and two High Speed Counter Inputs 76.
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~'` Program ROM 32 contains a program which is executed by proces!~or 20 to control blending operations and contains system configuration data, both of which is 15 described in detail belaw. Non-volatile memory 44 contains several types of infonnation which may be added, deleted or amended as required and each of these ty~s of in~ormation is described in turn below.
Controller 10 comprises extensive reporting facilities to add~ess regulatory 20 and user needs. Specifically, a~ will also be fbrth~r de~eribecl belaw, the occurrence of certain pre-s~lected event~ re~ults in controller 10 c~ea~ing tran~action records in non-` i volatile memory 44. In ~e ple~erTed embodiment, non-Yolatile memory 44 is de~igned to maintain appro~imat~ly 500 transaction records in a lFirst In First Out (FIFO) ~queue.
Transaction ~cords may be transferned ~rom ~he queue to a rennote device through RS485 "` 25 port 36 for either storage or printing out as desired. In ~he event that a sys~m is ~, contemplated wherein more ~an 500 transactions may occur between transfiers, the size `; of vola~le memory 44 may be increased to provide the desired queue size.
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Transaction records are created for events (transactions) such as system ~ power-up, commencement of blending operations, each additive injection, completion of blending operations, occurrence of faults, modification of pr~luct ratios, etc. Such transaction records will preferably include the time and date at which the transaction S occurred, the type of transaction and any associated data, such as the amount of additive injected or the type of fault which occurred.
Non-volatile memory 44 is also used ~o store additive information (i.e. -' recipes) for various finished products. In the preferred embodiment, non-volatile memory ,~10 44 can store information for up to eight different finished products, including up to three `; additive types and ratios for each product.
, Non-volatile memory 44 also stores values for main product flow meter and additive flaw meter Meter Factors and Calibration Factors. The Meter ~;actor; are u9ed 15 to establish a rough relationship between the volumc of product pa99illg through the flov~
~' meter and the number of pulses generated by that meter. The Calibration Factors are used to 'fine tune' the Meter Factors ~or greater accuracy. For example, a main product flow meter could be specified as producing ten pulses per U.S. gallon and an additive flow meter could be specified as producing fifty pulses per litre.
A~ will be understood by those o~ sl~ll in the art, within controller 10, all :~
; product defiDitions and in~ormation is represen~ed in generic engineering units and products a~e defined in terms o~ the number o~ unit~ o~ addlitive per units of Illaifl product. Accordingly, using the Meter Pactors given abave9 if U.S. gallons are selected .-~ 25 as the prefe~ed unit, ~he Meter Factor stored in non-volatile memory 44 fior the main product ~low meter would be ten and ~e Meter Factor for ~Ihe additive flaw meter would .~ .
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be one thousand, eight hundred and ninety-two point seven zero five (i.e. - 50 pulses per litre times 3.785411 litres per U.S. gallon).
Alternatively, if litres are selected as the preferred unit, the Meter Factor S for the main product flow meter would be selected as two pOillt six four one seven and the Meter Factor for the additive flow meter would be fif~y. 'rO accommodate the fact that some meters provide a non-integer number of pulses for Isome desi~d units (as is apparent from the examples above), the above-mentioned Meter Factors are in fact~` scaled-up, prior to entry in controller 10, by a factor of one thousand. Thu~s, in the latter 10 example above, the main product Meter Factor would be two thousand six hundred and . .
- forty-two and the additive Meter Factor would be fifty thousand.
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` ~ The calibration factors for additive flow mete~s are determined by arranging to receive the ~aw of additive into a graduated vessel by, for example, moving a three-` 15 way valve to a test position, and then depressing momentary contact switch 50b on ,~ keypad 24 which is the CALIBRAlE switch. Once depressed, controller 10 injects the preselected quantity of additive, as determined in view of the additive meter factor, into ., , `~ the g~aduated vessel. The preselected volume of addidve is divided by the meas~
3 volume to de~ennine the calib~ation factor. This factor is multiplied by ten thousand to `~ 20 allQw elimination of the decimal point and is stored in non-volatile memory 44.
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`, As will be apparent to those of skill in the art, if ~e properties o~ one or `~j more o~ the i~ow meter~ in the system vary due to changes in f~ ate or vi~cosi~, the calib~a~on procedure may be performed again and the calibration factor adjl~3ted.` 25 accordingly. Further, if any of the flow meter3 used in the syseem are subsequently ` .. replaced, due to failures or redesign, it is only rlecessary to adjust the pre~efined Meter . . . ~
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., . Pactor and Calibration Factor associated with that flaw meter rather than change stored ``i product definitions.
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s~ ~ Non-volatile memory 44 also stores various system variables. For examplel 13 5 in a block v,~ e system, a.certain amount of additive is present in the additive line , j ', between the block valve and the flow meter. When the block valve is closed, the additive remaining in the line 'dribbles' through the additive flow meter ;ncreasing the amount of `j additive injected into the main product flow. Controller 10 monitors the additive flow meter when the block valve is closed and determines the amount o~ this dribble. A value ; ~ 10 representing the amount of dribble (the dribble factor) is stored in non-volatile memory 44 and is used by controller 10 to decrease the amount o~ addidve inject~d prior to the close of the block valve by a lilce amount. Thus, the sum of ~e additive injected prior to the block valve closing and the dribble which occurs after the close of the block valve ; ~ is equal to the predefined required amount of additive. Each additive may h~ve its own ~`~ 15 dribblo factor depending on the physical characteri~dcs of the block valve and fl~w meter . ~1 and the addidve. Therefore, separate dribble factors are m~untained for each additive line ~ and are adjusted on an ongoing basis.
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Similarly an injection offset factor is stored in non-volatile memory 44.
. 20 This o~set factor deter~s~ines at what point the blending ope~ation i3 initi~ted. For ` ~ e%ample, without an offset (or with an offset of zero), a blellding opera~ion occurs when the pulses received from ~ main produc~ flaw meter, afler scaling, equal the pre~efined - 3 value sto~ed in non-Yolatile memory 44 for the desi~ed finished product. Thi~ pre~efined value represents ~e volume of main product to which additive should be added.
25 Depending upon several facto~s, this volume can be se~eral ~en~ of gallons or more.
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When a blending operation terminates prior to the above-mentioned pre-defined volume of ma~n product passing through the main product flaw meter, either due to normal termination of a finished product run or due to an error condition, the blending opera~ion will not have occurred. Thus, the final volume of main prcduct will haYe had S no additives injected and thus the overall ratio of additives in the finished pr~duct will be below that desired. Accordingly, an injection offset can be pre-set to initiate the injection operation after a pre-defined minimum number of pulses hav~ been received from the main product flow meter. In this case, while a pre-defined volume of additive is still injected for the pre-defined volume of main product, ~he injection operation is ~i3 lO commenced prior to the complete prei-defined volume of main pro~uct passing through the main product flow meter.
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It is contemplated that the offset will norrnally be equal to one half o~ the pre-defincd number of main product flaw metcr pulses. In thi~ case, the maximum 15 shortfall in the volume of additive injected is reduced to one half of the volunne injected during each injection operadon and, on average, should be reduced even lower.
, Finallx non-volatile memory 44 contain totals for: the volume of each aWitive injected; the volume of main product blended; the volume of finished product . 20 blended. These totals are updated by controller 10 dunng each blending operation.
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"~ As is described below, controller 10 also comp ises an extensive error checking regime. As part of this ~gime, the controller receives various statu~ signals from componellt3 of ~he blending system and these status signals are monito~ed to ensure 25 proper operation of the blending system is occuniog. Pr3vided that ~e status signals ind;cate that proper opera~on is occulTing, the controller maintains various enable signals to blending system component. If the controL'er de~rmines that one or mo~e ~tatus ;`~`` . .
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: ` signals are not nominal, the enable signals are removed in a controlled manner, resulting ~; in the blending system shutting down safely, if possible.
Preferred embodiments of the present invention will now be described with :~' 5 reference to the following eLamples of representative installations. The ~onfiguration of controller 10 for each of the installations discuss~ below is accomplished by selecting '~ one of a series of pre-defined configurations which are stored in Program ROM 32. It is contemplated that such selection will be effected through hardware switches, such as ., a DIP (Dual Inline Package) switch located within controller 10, at the time of installing ',, 10 the controller, If the system is altered after installa~on7 the co~lguration may simply bc updated as required by altenng the DIP switch set~ngs.
Figure 4 shows a schematic representation o~ the present imlention when employed in an additive control system for controlling up to two simultaneou~ (parallel) 15 additive blending operations. Such a system may be employed, for example, in blending ` ', jet engine fuels wherein an identification dye and a vaporization enhancer may be added to the fuel.
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: ~ The main product line 1~ of the system includes a main product supply ~, ~, 20 104, main product ~ump 108, main product pre~ure sensor 110, main product contrd ;" valve 112, main product flow meter 116, additives injectioll point 120 ~nd finished ;~ product storage 124, Each additive line 126 of the system includes an additive supply 128, an additive pump 132, an additive pressure sellsor 134, a block valve 136, a flaw meter 140 and injection line 144, Injection line 144 feeds into inject~on point 12û on :j 25 main product line 120 at a poialt upstream of the finished product sto~age 124. In this manner, adequate n~ixing of ~e additives and main product is ensured prior to their entry t into the finished product storage 124, :', ., , : ;3 .,:' :, ::
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It should be understood that finished product storage 124 can be any suitable product storage device, including a holding tank, transpon truck, pipeline, packaging machine, or any other suitable as would be apparent to one of skill in the art, It should i?j also be understood that while Figure 4 shows a controller capable of two simultaneous "~ S blending operations, the present invention is not limited to systems employing two ~` simultaneous blending operations and in fact in many circumstances it is contemplated :` that the number of desired blending operations may ~ary from one to fo~lr or more.
. Main product flow meter 116 includes a signal lin~ 200 which is connected - 10 to one of High Speed Counter inputs 76 of controller 10. Similarly, each additive flow meter 140A, 140B includes a signal line 204A,204B which are each connel ted to one of ` Digital inputs 72 of controller 10.
As mentioned above, controller 10 comprises an extensiv~ error checking ~, 15 regime. As part of this regime, several status signals are provided to cootroller 10.
Main product pressure sensor 110 provides a status signal 220 to controller 10 and each additive pressure sensor 134A, 134B pravides a sta~us signal 224A, 224B to controller - 10. Each of the ab~e-mentioned s~atus signals is connected to one of Digital inputs 72.
Further a Master Enable signal 226 is prwided to controller 10 to indicate that operation 20 of the blending sys~m is co~ectly authorized. Mas~er Enable signal 226 can beprovided, for example, from a limited access remote terminal ~hrough RS485 port 36 or ~rom a key opera~d switch connected to one of Digital inputs 72.
,' ~` Controller 10 pro~ides several enable signals to componenf~ o~ the blending 25 system as part of the error checl~ng regime. For ex~nple, main product pump 108 receives an Enable signal 208 from one ~ Isola~ed h~ Qutputs 68 on controller 10 and main product control valve 112 receives an Enable signal 212 f~om another of Isolated , . ~
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~AC Outputs 68. In a similar manner, each additive pump 132A, 132B receives an enable `'~signal 216A, 216B from another of Isolated AC Outputs 68.
jProduct configuration commands may be received from keypad 24 or from S RS485 port 36 through a remote terminal to select one of the eight finished products ; 'istored in non-volatile memory 44 or to change the stored information for a particular product.
jWhen selected from keypad 24, momentary contact ~switch 50a, which is the ; 10 PARAMETER switch, is pressed. This causes display 40 to display a parameteridentification number in the three leftmost digits. In the preferrgd embodiment there are 90 parameters available, although not all are used in most configurations. The user repeatedly presses either momentary contact switch SOc, which is the DOWN ~witch, or `momentary contact switch 50d which is the UP switch until the parameter ;dentification ; 1 15 number for the current product is displayed. For ex~mple, parameter 31 may represent ~`the recipe for a first stored finished product defiaition. When the correct parameter ;- ~number is displayed, the user presses the CALIBRATE switch and display 41) alters to 'ishow the current contents of the selected parameter. The contents of the parameter may then be altered as required by pressing the UP or DOWN buttons. When the alterations 20 are complete, the user again presses the CALIBR~TE3 but~on to comple~e the entry.
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~` ~This process may be used to alter the stored recipes, the curren~y selected finished product, and to displa~ accounting totals maintained by t~e ys~em. In the latter case, the pa~ameter representing the desi~d total is selec~ed as above but the system will `~ 25 only display the total and will not allaw the user to mo~ify it. Modification of accounting t~ls reguires eidler changing the above-mentioned configuration DIP switches to a special mode or the pravision of a special command through RS485 port 36.
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- It is contemplated that, in the preferred embodiment, selecting or altering the stored information for a finished product will also result in controller 10 generating a transaction record in non-volatile memory 44. Once the system has been correetly configured, by selecting a pre-definsd finished product or by defining a new finished product, blending operations may proceed. The operation of the system shown in Figure 4 will now be explained with reference to the flow charts o~ Figures 5 and ~.
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First, at block 500, the controller ensures that Master Enable signal 226 is present which indicates that use of the system is properly authorized. A transaction record is created and stored in non-volatile memory 44 indicafing the time and date o~ the `1 recèipt of the Master Enable signal. If Master E~nable signal 226 is not present, controller 10 remains in an IDLE state and no further steps occur until it is prwided.
In fact, as will be understood by those of skill in the art, the presence of Master Enable !
signal 226 is checked in real time (i.e. - interrupt-driven) such that controller 10 may substanti311y immediately react to its removal at any time. Depen~ing upon the cunent .
state of the blending operations, the remaval of Master Enable signal 226 rnay result in `~ ~ the controller returning to the IDLE state or may result in an Emergency Shut Dawn, as , is describsd below.
. . ..
Next, at block 504, the controller performs an internal check to ensure ~hat a finishsd produst has been properly selectcd and that the definition thereof is consistent.
If no finished product has been selected the controller ws~it~ for such a selectiosl to oc~ur, `~ otherwise a transaction record is created indicating the finished product which is selectRd.
As shown at block S0~, enable signals are next provided ~o each addidve pump 132~, 25 which is required to make the selected finished pr~uct and to main prodLIct pump 108.
A transaction record is created indicating the enablement of the pumps.
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-17- 2~ 6 Controller 10 then checks pressure sensor 134 for each required addi~ive supply to ensure that additive is being correctly provided, as indicated at block 512 If i an incorrect status signal is received from pressure sensor 134 for one or more requir~
additives, the controller proceeds to an emergency shut-down (ESD) as indicated at block 5 513. Otherwise, controller 10 next checks main produ~t pressure sensor llû to ensure that main product is being correctly provided, as indicated at block 514. Again, if an incorrect status signal is received from pressure sensor 110, the controller e~Gecutes an . emergency shut down as indicated at block 515.
. ~
At block 518, the controller is ready to commence blending operations once main product control valve 112 is opened. Depending upon the particular implementation employed, the main product control valve 112 may be opened by controller 10 once block i 518 is reached, or when used at locations such as a truck Iceylock station, etc., it may be opened by an operator-activated switch.
,`:``. 15 As indicated at block 522, when main pr~duct control valve 112 i5 opened, a main product timer starts running and if controller 10 does not receive signal pulses from main product flow meter 116 within a predefined time span, the controller pr~s ~`~ to an emergency shut-down as indicatcd at block 523. This pre-defined ~ime span is ~ ~ 20 another system variable which is stored in non-volatile memory 44 and may be altered ;~ depending upon the main product's characteris~cs as well as those o~ the main product flow meter. Provided that signal pulses aIe received at ~he controller within the predefined ~me span, blending opera~ons commence as indicated at connector 526.
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:; 25 As will be understood by ~hose of skill in the art, many of the opera~ons . described aba~e are conducted on a Real ~Ime ~interrupt-drivell) basis. ~or e~ample, as mentioned abave, if the Master Enable signal is remasted at any point during blending ;''.
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operations the controller will respond by entering the IDLE state or by executing an emergency shut-down depending upon the status of the blending operations. Similarly, if at any time during blending operations the pressure reported by additive pressure sensor 134 drops below a predefined minimum, controller 10 executes an emergen~y shutdown.
S Also, if at any time during blending operations controller 10 ceases to receive signal pulses from main product flow meter 116 for more than the pre-defined time span,controller 10 executes an emergency shutdown. Finally, if at any time controller lû
ceases to receive the correct signal from main product pressure sensor 110, an emergency ~ shut down will be executed.
`'` 10 Figure 6 indicates the steps in the blending operations from connector 526.
- ~As shown at block 600, controller 10 counts and scales the pulses received frorn main product flow meter 116 until the count is equal to the pre-defined scaled value representing the desired volume of main product less the injection offset, if any.
Additive block valve 136 is then opened at block 604 and controller 10 `~commences counting pulses from additive ~qow meter 140 at block 608. If pulses are no~
,~received from additive flow meter 140 within a pre-defined dme span, as indicated at block 612, controller 10 e~ecutes an emergency shut down at block 613 i 20 .At block 616, ~he controller compa2es the scaled ~otal of the pulses received from ~e addi~ve flaw meter with the pre~efined sealed value representing the desired volume of additive which is stored in non-volatile memory 44 less the dribble factor, if :~any. If the scaled total of the pulses equals the pre~efined value, the additive block .~ 25 valve is closed as indicated at block 620 and the cont2oller chec~s the actual dribble ... .
.,factor for the additive block valve and updates the value stoFed in non-volatile memory 44 if requi~ed, as indicated at block 624~
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, -19-Finally, as indicated at block 628, controller 10 continues counting and ~, scaling main product flow pulses throughout the blending operation until the scaled count is equal to the pre-defined scaled value in non-volatile memory ~. At this point, con~roller 10 resets the main product counter and the blending operation restarts at block i; 5 600.
-'-s - ' While the discussion above refiers to a single additive flaw rneter and block valve, it will be apparent to those of skill in the art that ~wo or more additives may be similarly injected, either in parallel or serially, if desired. The ope;rations indicated by - ~ 10 blocks 604 through 624 are conducted for each additive to bc blended as will be apparent ` ~ to those of skill in the art.
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Figurc 7 shows a schematic representation of a another blending syst~m in `' accordance with the present invention, wherein similar components to those of Fi~gure 4 15 are identified with the same reference numbers.
In this embodiment, the additive block valves and flow meters of the '. previous embodiment have been replaced with piston injectors 7~). These piston injectors are preferably bidirectional but may be uni-directiollal as would be apparent to 20 ~hose of skill in ~he art. Each injector 700 includes an injec~on confinnation signal line 7W which p~vides a signal to controller 10 confirming that each injection has in ~act occurred. Each injector recei~s its inject signal from controller 10 through injector `~: . control line 712.
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The operation of this embodiment is similar to ~at of the previous ` embodiment discussed above. Essentially, the operations shawn in ~he flawchart of E~igure 5 for the previous embodiment are ~he same fior this embodiment, with only the ~'' . -, . .. . .
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: blending operations (indicated at connector 526 of Fi~ure S) being significantly different.
The blending operations of this embodiment will now be described with ref~rence to the flow chart of Figure 8.
, SAs indicated at block 750, controller 10 receives pulses from main product - f~ow meter 116 and counts and scales the pulses until the scaled count equals the prese~
~-1 value less an offset, if any. When the scaled count equals tlhe preset less the ol~set, ;~ controller 10 initiates an injection operation by asserting the injector signal through ~ injector control line 712, as shown at box 754 and a transaction recor~ is created.
';,,J 10Controller 10 checks the status of injector confirmation signal on line 704 to ensure that `~ the additive was in fact injected, as indicated at box 758. If the injection confirmation . signal is not present9 controller 10 executes an emergency shutdown as indicated at box 762 and creates an appropriate transaction record. As indicated at box 766, if the ` ~ injection confirrnation signal is present, controller 10 continues to count and scale the 15 main product pulses until the preset value is reached, at which time the cycle repeats.
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~ ~ Figure 9 shows a schematic representation of a another blending system in ~ accordance with the present imention, wherein similar components to those of Pigure 4 `~ are identified with the same rei~erence numbers.
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In this embodiment, which i3 parti(:u~ y suited for strea~ng-type . ~
operations, ~e additive block valves and flow meters ~f the embodiment o~ Figure 4 have been replaced with variable flaw rate valves 800. Valve3 800 o~n and close in proportion to the DC current level in v~lve control line 80~.
Again, the operation o~ this embodimen~ is simil~ to that of the embodiment of Figure 4, discussed above. Essentiially, the operations shawn in the fl~wchart of .~
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Figure 5 for the embodiment of Figure 4 are the same for this embodiment, with the only ; the blending operations (indicated at box 526 of Figure 5) being significantly different.
The blending operations of this embodiment will now be described with reference to the :; 5 flow chart of Figure 10.
,,, 5 ' `, In this configuration, non-volatile memory 44 ~urther contains an initial value for the DC current on control line 804, which represerts the position to which additive valve 800 is initially opened. Further, non-volatile memory 44 contains a ratio . of scaled additive pulses to scaled main product pulses for each additive, a variation v~lue 10 below which error, in additive ratios are not corrected and a step value whieh repre~en~, the incremental change made to additive valve positions.
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As indicated at box 850, blending operadons commence with controller 10 opening the additive flow valve to the predefined initial position. Controller 10 then 15 checks to ensuFe that pulses are being received from additive flow meter 140 at box 854.
If pulses are not received, controller 10 executes an emergency shut-d~wn as indicated ~-; at box 858. Providing that pulses are being received, controller 10 counts and scales the ~, pulses from additive flow meter 140 and main product flow meter 116 for a p~e-defined ~ time period and calculates a ratio therebetween as indicated at box 862. The calculated ;-~ 20 ratio is compared to the predefined value at box 866. If the ratio is lawer than the predefined value by more than the variation value, the dc cur~nt to addi~ve flow valve -~ i; 800 is increased by the predefined step value as shown at box 870 and the blending ~ycle continues at bo~ 862.
Alternatively, if the ratio is higher than the predefined value by more than the predefined variation value, as indicated at box 874, the DC culTent to additive valve ~' flow valve 800 is decreased by the predefined step value at box 878 and ~he blending .
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` 1 5 In a more preferred embodiment, as will be apparent to those of skill in the art, non-volatile memory 44 contains a lookup table of step values for use at boxes 866 i~ and 874, with large step values being employed for large ra~io difference~ and small step ;~; values beinB indicated for small ratio differences. In this mannler, it is contempla~ed that i~ better averall blending ratios will be obtained.
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;~ The Emergency Shut Down procedur~ ferred to above, is naw described, with reference to the flowchart shown in Figure 11. As indicated at box 900, first the ~'j Enable signals are removed ~om additi~re pumps 132 and main product pump 108. Next, depending upon the current configuration of the blending system, either additive block .~ 15 valves 136 are closed (box 904a) or additive flow ~alves 800 are closed (box 904b) Of injector control signal 712 is removed from injectors 70~ (box 904c). Next, as indicated - ~ at box 908, main product block valve 112 is closed. Finally, an indicative error message ~: is displayed on display 40 and/or is transmit~d through RS485 por~ 36 as shown a~ box ;, 912. Of course, a ~ansaction record is also created indicating the source of the error condition.
It will be appa~ent to those of skill in ~e art that one or more of the abave-described blending system~ can be combined as required. For example, a controller in accordance with the present i~ention may be used with a system comprising a fl~w. .,~
, 25 meter and block valve additive line and a piston injector additi~e line. Similarly, a `'`~3 syste~ comprising a piston injector additivs line aad a streaming additive line may bs employed, or any combination of the abwe-described systems as may be ~equired. As :
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will be apparent to those of skill in the art, any such a combination system will operate witll the appropriate blending operations (as shown in Figurcs 6, 8 and 10) occurring simultaneously, in series or in parallel.
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It will be understood that, while specific preferz~d embodiments have been described aba~e, variations will be apparent to those of skill in the art and should not be -'. considered as departing from the scope of the present invention as defined in the claims appended hereto.
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S The present invention rel~tes to additive blending systems ~pecifically, the present invention relates to a novel method of controlling an additive blending system and to a novel additive blending controller.
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`. BACKGROUND OF THE INVENTION
_ _ ''. 10 In many fields it is necessary to blend additives with a main base product ~1 ' to fiorm a desired finished product. Typically, such additives need to be added Ito the main base product in precise ratios to obtain the required properties in the finished `~ product. Blending additives at ratios other than a specified ratio is undesired, both `~ 15 because the finished product may not perforrn to s~cifications and ~ecause many additives are relatively expensive and it is uneconomic to waste additive by exceeding the required ratios.
~, j ~ Non-limiting e~amples of products which undergo additive blending include:
; ~1 20 gasoline and jet fuels; lubricants; paints; vaIious food products; fier~ ers; and pesticides.
~¦ Systems for controlling the blendillg o~ additives with a base product at required ra~ios are Icnowll. Such systems typically empl~y a flow meter which outputs " .~ .
a signal every time a pre~efined amount of main product ha~ passed through the flow ~`; 25 meter. In response to that signal, a pre~efined amount of an additive is blended into the main product.
Several difflrent types of blending systems are kn~wn, perhaps the most common type employing additive injectors which are piston injecto~. These systems , :.
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~' ', - 1 ~, 2 :, ~, inject a pre-determined amount of an additive on each stroke of the piston. In response ~ ~ to a signal from a main product flow meter, the piston injector is stroked to inject a pre-- ~ defined amount of additive.
-,' Another type of blending system is the block valve blending system. In this ~ system a solenoid operated on-off, or block, valve is connect~i to a pressurized supply - of additive. An additive flow meter is connected between the Iblock valve and the main product line and, in response to an 'inject' signal from a flow rneter in the main product line, the block valve is opened by a controller, allawing additi~re to flow through the - 10 additive line flow meter and into the main product line. The controller receives 3ignal5 froni the flow meter in the additive line and, when a signal corresponding to a pre-` defined desired amount of additive is received, the controller closes the block valve.
Each time the controller receives the inject signal from the flow meter in the main ~, product line the process is repeated.
. 15 Yet another type of blending system is injector streaming. In streaming - systems, a controller rnonitors the main product line to determine the rate of flow, i.e.
~ . number of gallons per minute, etc. A second flow meter in the additive line allows the - ~ controller to deterrnine the flow rate of the additive. The controller o~rates a variaUe ~; ~ 20 position valve to adju~t the ~low of additive into the main product line. Por ex~mple, if the desired ratio of additive to main product was 10 ounces of additive per each five gallons of main product and the main product is flowing at ~ gallons per minute, the controller opens the va iable additive valve un~l the additive line flow meter outputs a signal indicating a flaw rate of 80 ounces of additive per minute.
Con~ollers for each o~ the above-mentioned techniques are known and range i ~om hard-wired systems, wherein for example the main product flow meter produces a ; `.
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2~7~(i : -3-pulse which directly triiggers a piston injector, to more sophisticated systems such as that shown in U.S. Patent 5,118,008 to ~lliams.
-~' The ~Illiams reference shaws a microprocessor baseid controller which S receives signals from a main product flaw meter and operates a block valve to supply additive accordingly. The controller counts the pulses received from the additive flow meter and compares the count to a pre-defined value in its memory. When the count equals the pre-defined value, the controller completes the injection cycle by shutting the ; ~ additive valve.
`~` 10 However, problems and/or disadvantages e~ist with the prior art systems.
~'f Such systems typically are only able to control a single type of iniector, such as block ``~ injectors or piston injectors. Also, the prior art systems cannot control more than a ., 3, single additive injection. When blending a product which includes se~eral additives, . ~ 15 either multiple controllers are required to be employed, one for each additive, or the ~ product must be blended in several product runs, one run for each additive required.
; ;~ Further, such systems typically require a manual re-configuration of the system for each . .ished product to be blended, with the ratio of additive to main product being manually adjusted either physically, by changing the flaw meters, or electrically b~3r replacing the 20 pre-defined values stored in the controller.
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Perhaps even more disadvantageous is the fact tha~ only ~he most limited ~ .`!
; ~ error-checldng alld/o~ repor~ing capabilities are provided in ~he prior art system3. The lack of error checl~ng and reporting c~pabilides is inc~ ingly becoming of concern, ~:3 25 both to meet regulatory requirements and to ensure that produc~ e correctly and ` ~1 economically produced.
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`~ SUMMARY OF THE INVENTION
It is an object of the present invention to provide a novel method of :;~ controlling an additive blending system.
; 5 It is a further object of the present in~ention to provide a navel conkoller for an additive blending sys~em.
According to a first aspect of the present invention, there is provided a , 10 method of controlling a blending system process comprising the steps ofo ;i (i) defining a desired ratio of an additive to a main product;
~ ' (ii) providing a flow of main product;
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'~j (iii) measuring the volume of said main product flow;
~ ., '. (iv) adding a predefined amount of at least one additive to said measured main : ~ 15 product flaw to achieve saud desired ratio;
(v) creating a non-volatile record indicating the time, date, amount and type ofi~ additive added in step (iv); and : ;' (vi) repeating steps (iii) and (v) as necessary until the process is tersninated.
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;:~ 20 Preferably, the method alllows the simultaneous or sequential blending of more ehan or~ additive, if ~equin:d, and allaws for more than a single type of blending 3 OpeI'atiOIl to be employed. Also preferably, the method includes error-checking ~, capabilities to ensure proper flow rates and correct operation of the sys~m and further ~: ~emoves enabl~ signals and/or plwides inhibit signals ~o cease ~pera~on of the system ~:~ 25 once an error condition has been detec~ed. Also p~e~erably, the method includes the `.` production of a transaction r~cor~ of all significant operations conducted by the sys~em, . .
such transaction records being sufflciently detailed to sati~fy regulatory ~equi~ements.
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~' :, ` ~~ 5 According to another aspect of the present invention, there is provided a conkoller for an additive blending system to blend at least one additive to a main product at a predefined ratio, l~omprising:
;1 main product volume measurement means;
S program storage means;
non-volatile memory means;
~ at least one additive supply control means; and `-` processing means responsive to said main product volume measurement means and operating said additive supply control means to provide a volume of additive to said main i' 10 product volume to achieve said predefined ratio, said processi~ means creating a record in said non-volatile memory means including the date and time said additive vo~ume was pravided and the volume of additive provided.
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Preferably, the controller is easily configurable to control one or more types 15 of blending operations. Also, it is preferred that the controller be able to conduct at least two different additive blending operations at the same time, either sequentially or in parallel, and that the diffe~nt operations may be effected by different types of blending - ~ operations, such as block valve and streaming. Also pre~erably, the controller includes a non-volatile memory which allows the storage of pre~efined ratios and the additives ~0 for two or more finished prQducts.
`~'1 Also prefierably, the controller maintains a recor l in non-volatile memory ` ~ of transac~ons conduc~:d by the controller, including tot~ls of finished product, additives adde~ and time and date of the transactions. Also preferably, the controller includes 25 means to storei the operating characteristics of the equipment ~o which it is a~tached to .j `~; minimi~e 'dribble' or other process variation. Further, it is preifi~rred that the con~roller be provided with communications capabilities allowing remote access from authorized . ,~
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data communication devices such as microcomputers, etc. and that such remote access '!~ includes configuration and reporting functions. It is also preferred that lhe controller . ~ includes a simple to use and easily understood data-entry keypad and digital readout :`',' ; .
S E~RIEF DESCRIPTION OF THE l:~RAWINGS
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: ~. Preferred embodiments of the present invention will now be described, by way of example only, with reference to the attached figures wherein:
Figure 1 shows a block diagram of a blending system controller;
, 10 Figure 2 shovs a keyboard and display module for the controller of Figure l;
Figure 3 shows a schematic representation of input and output ports of the controller of Figure l;
Fi~ure 4 shows a schematic representation of a blending sysS~m emplaying the ' controller of Figure l;
` ' 15 Figure S shows a flow chart of the initialization steps of the controller in the system of ~;igure 4;
Figure 6 shows a flow chart of the blending operations of the system of Figure 4;
~:` Figure 7 shows a schematic represenhdon of another blending system employing the controller of Figure l;
, 20 Figure 8 shows a flow chart of the blending operations of the system of Figure 7;
Figu~ 9 shows a schematic representa~on o~ another blending system employing the controller of Pigure 1;
Figure 10 shaws a i~ow chart of the blending operatioa~s of ~he system of Figure7; and Figure 11 shaws a flow chart of an Emergen~y 5hut Dawn proced .
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DETAILED DESCRIPTION OF THE PREFERRE~ EMBODIMENT~
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1 Referring now to Figure 1, a block diagram of a blending system controller - ~ in accordance with the present invention is shown. The controller, indicated generally at 10, includes a processor unit 20, a keypad 24, a battery bac~ up Real l~lme Clock IC) 28, a program RQM memory 32, an RS485 communications port 36, a display . ~ 40, a non-volatile memory 44 and valious input and ou~tput (I/O) ports 48 as will be described in further detail below.
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The above-mentioned components of the controller are commonly a~ilable and the present invention is not particularly limited to particular devices. In the preferred . ~ embodiment, processor 20 is a Z-80 microprocessor and Real rlme Clock is a MK~48T08 device manufactured by SGS Thomson Microelectronics. Similarly, in the prefe~d - -~ embodiment, RS485 communications port 36 is a Z84C40 device also manufac~ured by - ~
;, 15 SGS Thomson Microelectronics. Program ROM 32 may be any suitable ROM, EPROM, EEPROM or similar device and non-volatile memory 44 may be battery backed-up static I CMOS RAM devices, or other devices as would be apparent to those of skill in the art.
`~1 Figure 2 shaws a pre~erred embodiment of k~ypad 24 and display 40. In this pre~erred embodiment, ~eypad 24 and display 40 are combined into a single ~;; inteBrated module which may be mounted in any conveniealt place on the injection system. Keypad 24 includes four momentary ontact switches, 50a through 50d, as will ` ` ~ be desenbed in more detail below, and display 40 includes a six-digit digital display 54 " ~ and three status indicators 58a through 58c. Digital Display 54 may be LCD or LED-based or any other suitable type of display as would occur to those of skill in the art and status indicators 58 may be LED, neon, ineandesceDt lamps, or any other suitable; indication means as also would occur to tho3e of skill in the art.
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Status indicator 58a, the COM indicator. Iights when commur~ications are ,'! occurling through RS485 port 36. Status indicator 58b, the ARMED indicator, lights ;~ when the controller is enabled and is ready to commence blending opeTations. Finally, status indicator 58c, the CY~LES indicator, lights each time a blending c;~cle .
S commences. These operations are described in more detail below.
I/O ports 48 may include many different types of input and output signals, as required for a particular system. The I/O ports of the prefierred embodiment, as shown in Figure 3, include two isolated DC Outputs 60, a four to twenty milliamp10 variable DC output 64, eight isolated AC Outputs 68, twelve Digital (ON-OFF) Inputs 72, and two High Speed Counter Inputs 76.
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~'` Program ROM 32 contains a program which is executed by proces!~or 20 to control blending operations and contains system configuration data, both of which is 15 described in detail belaw. Non-volatile memory 44 contains several types of infonnation which may be added, deleted or amended as required and each of these ty~s of in~ormation is described in turn below.
Controller 10 comprises extensive reporting facilities to add~ess regulatory 20 and user needs. Specifically, a~ will also be fbrth~r de~eribecl belaw, the occurrence of certain pre-s~lected event~ re~ults in controller 10 c~ea~ing tran~action records in non-` i volatile memory 44. In ~e ple~erTed embodiment, non-Yolatile memory 44 is de~igned to maintain appro~imat~ly 500 transaction records in a lFirst In First Out (FIFO) ~queue.
Transaction ~cords may be transferned ~rom ~he queue to a rennote device through RS485 "` 25 port 36 for either storage or printing out as desired. In ~he event that a sys~m is ~, contemplated wherein more ~an 500 transactions may occur between transfiers, the size `; of vola~le memory 44 may be increased to provide the desired queue size.
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Transaction records are created for events (transactions) such as system ~ power-up, commencement of blending operations, each additive injection, completion of blending operations, occurrence of faults, modification of pr~luct ratios, etc. Such transaction records will preferably include the time and date at which the transaction S occurred, the type of transaction and any associated data, such as the amount of additive injected or the type of fault which occurred.
Non-volatile memory 44 is also used ~o store additive information (i.e. -' recipes) for various finished products. In the preferred embodiment, non-volatile memory ,~10 44 can store information for up to eight different finished products, including up to three `; additive types and ratios for each product.
, Non-volatile memory 44 also stores values for main product flow meter and additive flaw meter Meter Factors and Calibration Factors. The Meter ~;actor; are u9ed 15 to establish a rough relationship between the volumc of product pa99illg through the flov~
~' meter and the number of pulses generated by that meter. The Calibration Factors are used to 'fine tune' the Meter Factors ~or greater accuracy. For example, a main product flow meter could be specified as producing ten pulses per U.S. gallon and an additive flow meter could be specified as producing fifty pulses per litre.
A~ will be understood by those o~ sl~ll in the art, within controller 10, all :~
; product defiDitions and in~ormation is represen~ed in generic engineering units and products a~e defined in terms o~ the number o~ unit~ o~ addlitive per units of Illaifl product. Accordingly, using the Meter Pactors given abave9 if U.S. gallons are selected .-~ 25 as the prefe~ed unit, ~he Meter Factor stored in non-volatile memory 44 fior the main product ~low meter would be ten and ~e Meter Factor for ~Ihe additive flaw meter would .~ .
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be one thousand, eight hundred and ninety-two point seven zero five (i.e. - 50 pulses per litre times 3.785411 litres per U.S. gallon).
Alternatively, if litres are selected as the preferred unit, the Meter Factor S for the main product flow meter would be selected as two pOillt six four one seven and the Meter Factor for the additive flow meter would be fif~y. 'rO accommodate the fact that some meters provide a non-integer number of pulses for Isome desi~d units (as is apparent from the examples above), the above-mentioned Meter Factors are in fact~` scaled-up, prior to entry in controller 10, by a factor of one thousand. Thu~s, in the latter 10 example above, the main product Meter Factor would be two thousand six hundred and . .
- forty-two and the additive Meter Factor would be fifty thousand.
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` ~ The calibration factors for additive flow mete~s are determined by arranging to receive the ~aw of additive into a graduated vessel by, for example, moving a three-` 15 way valve to a test position, and then depressing momentary contact switch 50b on ,~ keypad 24 which is the CALIBRAlE switch. Once depressed, controller 10 injects the preselected quantity of additive, as determined in view of the additive meter factor, into ., , `~ the g~aduated vessel. The preselected volume of addidve is divided by the meas~
3 volume to de~ennine the calib~ation factor. This factor is multiplied by ten thousand to `~ 20 allQw elimination of the decimal point and is stored in non-volatile memory 44.
.
`, As will be apparent to those of skill in the art, if ~e properties o~ one or `~j more o~ the i~ow meter~ in the system vary due to changes in f~ ate or vi~cosi~, the calib~a~on procedure may be performed again and the calibration factor adjl~3ted.` 25 accordingly. Further, if any of the flow meter3 used in the syseem are subsequently ` .. replaced, due to failures or redesign, it is only rlecessary to adjust the pre~efined Meter . . . ~
.
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., . Pactor and Calibration Factor associated with that flaw meter rather than change stored ``i product definitions.
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s~ ~ Non-volatile memory 44 also stores various system variables. For examplel 13 5 in a block v,~ e system, a.certain amount of additive is present in the additive line , j ', between the block valve and the flow meter. When the block valve is closed, the additive remaining in the line 'dribbles' through the additive flow meter ;ncreasing the amount of `j additive injected into the main product flow. Controller 10 monitors the additive flow meter when the block valve is closed and determines the amount o~ this dribble. A value ; ~ 10 representing the amount of dribble (the dribble factor) is stored in non-volatile memory 44 and is used by controller 10 to decrease the amount o~ addidve inject~d prior to the close of the block valve by a lilce amount. Thus, the sum of ~e additive injected prior to the block valve closing and the dribble which occurs after the close of the block valve ; ~ is equal to the predefined required amount of additive. Each additive may h~ve its own ~`~ 15 dribblo factor depending on the physical characteri~dcs of the block valve and fl~w meter . ~1 and the addidve. Therefore, separate dribble factors are m~untained for each additive line ~ and are adjusted on an ongoing basis.
.~
Similarly an injection offset factor is stored in non-volatile memory 44.
. 20 This o~set factor deter~s~ines at what point the blending ope~ation i3 initi~ted. For ` ~ e%ample, without an offset (or with an offset of zero), a blellding opera~ion occurs when the pulses received from ~ main produc~ flaw meter, afler scaling, equal the pre~efined - 3 value sto~ed in non-Yolatile memory 44 for the desi~ed finished product. Thi~ pre~efined value represents ~e volume of main product to which additive should be added.
25 Depending upon several facto~s, this volume can be se~eral ~en~ of gallons or more.
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When a blending operation terminates prior to the above-mentioned pre-defined volume of ma~n product passing through the main product flaw meter, either due to normal termination of a finished product run or due to an error condition, the blending opera~ion will not have occurred. Thus, the final volume of main prcduct will haYe had S no additives injected and thus the overall ratio of additives in the finished pr~duct will be below that desired. Accordingly, an injection offset can be pre-set to initiate the injection operation after a pre-defined minimum number of pulses hav~ been received from the main product flow meter. In this case, while a pre-defined volume of additive is still injected for the pre-defined volume of main product, ~he injection operation is ~i3 lO commenced prior to the complete prei-defined volume of main pro~uct passing through the main product flow meter.
~ .~
It is contemplated that the offset will norrnally be equal to one half o~ the pre-defincd number of main product flaw metcr pulses. In thi~ case, the maximum 15 shortfall in the volume of additive injected is reduced to one half of the volunne injected during each injection operadon and, on average, should be reduced even lower.
, Finallx non-volatile memory 44 contain totals for: the volume of each aWitive injected; the volume of main product blended; the volume of finished product . 20 blended. These totals are updated by controller 10 dunng each blending operation.
~.
"~ As is described below, controller 10 also comp ises an extensive error checking regime. As part of this ~gime, the controller receives various statu~ signals from componellt3 of ~he blending system and these status signals are monito~ed to ensure 25 proper operation of the blending system is occuniog. Pr3vided that ~e status signals ind;cate that proper opera~on is occulTing, the controller maintains various enable signals to blending system component. If the controL'er de~rmines that one or mo~e ~tatus ;`~`` . .
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: ` signals are not nominal, the enable signals are removed in a controlled manner, resulting ~; in the blending system shutting down safely, if possible.
Preferred embodiments of the present invention will now be described with :~' 5 reference to the following eLamples of representative installations. The ~onfiguration of controller 10 for each of the installations discuss~ below is accomplished by selecting '~ one of a series of pre-defined configurations which are stored in Program ROM 32. It is contemplated that such selection will be effected through hardware switches, such as ., a DIP (Dual Inline Package) switch located within controller 10, at the time of installing ',, 10 the controller, If the system is altered after installa~on7 the co~lguration may simply bc updated as required by altenng the DIP switch set~ngs.
Figure 4 shows a schematic representation o~ the present imlention when employed in an additive control system for controlling up to two simultaneou~ (parallel) 15 additive blending operations. Such a system may be employed, for example, in blending ` ', jet engine fuels wherein an identification dye and a vaporization enhancer may be added to the fuel.
' . ': !
: ~ The main product line 1~ of the system includes a main product supply ~, ~, 20 104, main product ~ump 108, main product pre~ure sensor 110, main product contrd ;" valve 112, main product flow meter 116, additives injectioll point 120 ~nd finished ;~ product storage 124, Each additive line 126 of the system includes an additive supply 128, an additive pump 132, an additive pressure sellsor 134, a block valve 136, a flaw meter 140 and injection line 144, Injection line 144 feeds into inject~on point 12û on :j 25 main product line 120 at a poialt upstream of the finished product sto~age 124. In this manner, adequate n~ixing of ~e additives and main product is ensured prior to their entry t into the finished product storage 124, :', ., , : ;3 .,:' :, ::
-14~ 7~
It should be understood that finished product storage 124 can be any suitable product storage device, including a holding tank, transpon truck, pipeline, packaging machine, or any other suitable as would be apparent to one of skill in the art, It should i?j also be understood that while Figure 4 shows a controller capable of two simultaneous "~ S blending operations, the present invention is not limited to systems employing two ~` simultaneous blending operations and in fact in many circumstances it is contemplated :` that the number of desired blending operations may ~ary from one to fo~lr or more.
. Main product flow meter 116 includes a signal lin~ 200 which is connected - 10 to one of High Speed Counter inputs 76 of controller 10. Similarly, each additive flow meter 140A, 140B includes a signal line 204A,204B which are each connel ted to one of ` Digital inputs 72 of controller 10.
As mentioned above, controller 10 comprises an extensiv~ error checking ~, 15 regime. As part of this regime, several status signals are provided to cootroller 10.
Main product pressure sensor 110 provides a status signal 220 to controller 10 and each additive pressure sensor 134A, 134B pravides a sta~us signal 224A, 224B to controller - 10. Each of the ab~e-mentioned s~atus signals is connected to one of Digital inputs 72.
Further a Master Enable signal 226 is prwided to controller 10 to indicate that operation 20 of the blending sys~m is co~ectly authorized. Mas~er Enable signal 226 can beprovided, for example, from a limited access remote terminal ~hrough RS485 port 36 or ~rom a key opera~d switch connected to one of Digital inputs 72.
,' ~` Controller 10 pro~ides several enable signals to componenf~ o~ the blending 25 system as part of the error checl~ng regime. For ex~nple, main product pump 108 receives an Enable signal 208 from one ~ Isola~ed h~ Qutputs 68 on controller 10 and main product control valve 112 receives an Enable signal 212 f~om another of Isolated , . ~
.
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~AC Outputs 68. In a similar manner, each additive pump 132A, 132B receives an enable `'~signal 216A, 216B from another of Isolated AC Outputs 68.
jProduct configuration commands may be received from keypad 24 or from S RS485 port 36 through a remote terminal to select one of the eight finished products ; 'istored in non-volatile memory 44 or to change the stored information for a particular product.
jWhen selected from keypad 24, momentary contact ~switch 50a, which is the ; 10 PARAMETER switch, is pressed. This causes display 40 to display a parameteridentification number in the three leftmost digits. In the preferrgd embodiment there are 90 parameters available, although not all are used in most configurations. The user repeatedly presses either momentary contact switch SOc, which is the DOWN ~witch, or `momentary contact switch 50d which is the UP switch until the parameter ;dentification ; 1 15 number for the current product is displayed. For ex~mple, parameter 31 may represent ~`the recipe for a first stored finished product defiaition. When the correct parameter ;- ~number is displayed, the user presses the CALIBRATE switch and display 41) alters to 'ishow the current contents of the selected parameter. The contents of the parameter may then be altered as required by pressing the UP or DOWN buttons. When the alterations 20 are complete, the user again presses the CALIBR~TE3 but~on to comple~e the entry.
~, .
~` ~This process may be used to alter the stored recipes, the curren~y selected finished product, and to displa~ accounting totals maintained by t~e ys~em. In the latter case, the pa~ameter representing the desi~d total is selec~ed as above but the system will `~ 25 only display the total and will not allaw the user to mo~ify it. Modification of accounting t~ls reguires eidler changing the above-mentioned configuration DIP switches to a special mode or the pravision of a special command through RS485 port 36.
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- It is contemplated that, in the preferred embodiment, selecting or altering the stored information for a finished product will also result in controller 10 generating a transaction record in non-volatile memory 44. Once the system has been correetly configured, by selecting a pre-definsd finished product or by defining a new finished product, blending operations may proceed. The operation of the system shown in Figure 4 will now be explained with reference to the flow charts o~ Figures 5 and ~.
.
First, at block 500, the controller ensures that Master Enable signal 226 is present which indicates that use of the system is properly authorized. A transaction record is created and stored in non-volatile memory 44 indicafing the time and date o~ the `1 recèipt of the Master Enable signal. If Master E~nable signal 226 is not present, controller 10 remains in an IDLE state and no further steps occur until it is prwided.
In fact, as will be understood by those of skill in the art, the presence of Master Enable !
signal 226 is checked in real time (i.e. - interrupt-driven) such that controller 10 may substanti311y immediately react to its removal at any time. Depen~ing upon the cunent .
state of the blending operations, the remaval of Master Enable signal 226 rnay result in `~ ~ the controller returning to the IDLE state or may result in an Emergency Shut Dawn, as , is describsd below.
. . ..
Next, at block 504, the controller performs an internal check to ensure ~hat a finishsd produst has been properly selectcd and that the definition thereof is consistent.
If no finished product has been selected the controller ws~it~ for such a selectiosl to oc~ur, `~ otherwise a transaction record is created indicating the finished product which is selectRd.
As shown at block S0~, enable signals are next provided ~o each addidve pump 132~, 25 which is required to make the selected finished pr~uct and to main prodLIct pump 108.
A transaction record is created indicating the enablement of the pumps.
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-17- 2~ 6 Controller 10 then checks pressure sensor 134 for each required addi~ive supply to ensure that additive is being correctly provided, as indicated at block 512 If i an incorrect status signal is received from pressure sensor 134 for one or more requir~
additives, the controller proceeds to an emergency shut-down (ESD) as indicated at block 5 513. Otherwise, controller 10 next checks main produ~t pressure sensor llû to ensure that main product is being correctly provided, as indicated at block 514. Again, if an incorrect status signal is received from pressure sensor 110, the controller e~Gecutes an . emergency shut down as indicated at block 515.
. ~
At block 518, the controller is ready to commence blending operations once main product control valve 112 is opened. Depending upon the particular implementation employed, the main product control valve 112 may be opened by controller 10 once block i 518 is reached, or when used at locations such as a truck Iceylock station, etc., it may be opened by an operator-activated switch.
,`:``. 15 As indicated at block 522, when main pr~duct control valve 112 i5 opened, a main product timer starts running and if controller 10 does not receive signal pulses from main product flow meter 116 within a predefined time span, the controller pr~s ~`~ to an emergency shut-down as indicatcd at block 523. This pre-defined ~ime span is ~ ~ 20 another system variable which is stored in non-volatile memory 44 and may be altered ;~ depending upon the main product's characteris~cs as well as those o~ the main product flow meter. Provided that signal pulses aIe received at ~he controller within the predefined ~me span, blending opera~ons commence as indicated at connector 526.
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:; 25 As will be understood by ~hose of skill in the art, many of the opera~ons . described aba~e are conducted on a Real ~Ime ~interrupt-drivell) basis. ~or e~ample, as mentioned abave, if the Master Enable signal is remasted at any point during blending ;''.
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operations the controller will respond by entering the IDLE state or by executing an emergency shut-down depending upon the status of the blending operations. Similarly, if at any time during blending operations the pressure reported by additive pressure sensor 134 drops below a predefined minimum, controller 10 executes an emergen~y shutdown.
S Also, if at any time during blending operations controller 10 ceases to receive signal pulses from main product flow meter 116 for more than the pre-defined time span,controller 10 executes an emergency shutdown. Finally, if at any time controller lû
ceases to receive the correct signal from main product pressure sensor 110, an emergency ~ shut down will be executed.
`'` 10 Figure 6 indicates the steps in the blending operations from connector 526.
- ~As shown at block 600, controller 10 counts and scales the pulses received frorn main product flow meter 116 until the count is equal to the pre-defined scaled value representing the desired volume of main product less the injection offset, if any.
Additive block valve 136 is then opened at block 604 and controller 10 `~commences counting pulses from additive ~qow meter 140 at block 608. If pulses are no~
,~received from additive flow meter 140 within a pre-defined dme span, as indicated at block 612, controller 10 e~ecutes an emergency shut down at block 613 i 20 .At block 616, ~he controller compa2es the scaled ~otal of the pulses received from ~e addi~ve flaw meter with the pre~efined sealed value representing the desired volume of additive which is stored in non-volatile memory 44 less the dribble factor, if :~any. If the scaled total of the pulses equals the pre~efined value, the additive block .~ 25 valve is closed as indicated at block 620 and the cont2oller chec~s the actual dribble ... .
.,factor for the additive block valve and updates the value stoFed in non-volatile memory 44 if requi~ed, as indicated at block 624~
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, -19-Finally, as indicated at block 628, controller 10 continues counting and ~, scaling main product flow pulses throughout the blending operation until the scaled count is equal to the pre-defined scaled value in non-volatile memory ~. At this point, con~roller 10 resets the main product counter and the blending operation restarts at block i; 5 600.
-'-s - ' While the discussion above refiers to a single additive flaw rneter and block valve, it will be apparent to those of skill in the art that ~wo or more additives may be similarly injected, either in parallel or serially, if desired. The ope;rations indicated by - ~ 10 blocks 604 through 624 are conducted for each additive to bc blended as will be apparent ` ~ to those of skill in the art.
,, , :- i ! ~
Figurc 7 shows a schematic representation of a another blending syst~m in `' accordance with the present invention, wherein similar components to those of Fi~gure 4 15 are identified with the same reference numbers.
In this embodiment, the additive block valves and flow meters of the '. previous embodiment have been replaced with piston injectors 7~). These piston injectors are preferably bidirectional but may be uni-directiollal as would be apparent to 20 ~hose of skill in ~he art. Each injector 700 includes an injec~on confinnation signal line 7W which p~vides a signal to controller 10 confirming that each injection has in ~act occurred. Each injector recei~s its inject signal from controller 10 through injector `~: . control line 712.
, .
.
The operation of this embodiment is similar to ~at of the previous ` embodiment discussed above. Essentially, the operations shawn in ~he flawchart of E~igure 5 for the previous embodiment are ~he same fior this embodiment, with only the ~'' . -, . .. . .
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: blending operations (indicated at connector 526 of Fi~ure S) being significantly different.
The blending operations of this embodiment will now be described with ref~rence to the flow chart of Figure 8.
, SAs indicated at block 750, controller 10 receives pulses from main product - f~ow meter 116 and counts and scales the pulses until the scaled count equals the prese~
~-1 value less an offset, if any. When the scaled count equals tlhe preset less the ol~set, ;~ controller 10 initiates an injection operation by asserting the injector signal through ~ injector control line 712, as shown at box 754 and a transaction recor~ is created.
';,,J 10Controller 10 checks the status of injector confirmation signal on line 704 to ensure that `~ the additive was in fact injected, as indicated at box 758. If the injection confirmation . signal is not present9 controller 10 executes an emergency shutdown as indicated at box 762 and creates an appropriate transaction record. As indicated at box 766, if the ` ~ injection confirrnation signal is present, controller 10 continues to count and scale the 15 main product pulses until the preset value is reached, at which time the cycle repeats.
.:~
~ ~ Figure 9 shows a schematic representation of a another blending system in ~ accordance with the present imention, wherein similar components to those of Pigure 4 `~ are identified with the same rei~erence numbers.
.~
In this embodiment, which i3 parti(:u~ y suited for strea~ng-type . ~
operations, ~e additive block valves and flow meters ~f the embodiment o~ Figure 4 have been replaced with variable flaw rate valves 800. Valve3 800 o~n and close in proportion to the DC current level in v~lve control line 80~.
Again, the operation o~ this embodimen~ is simil~ to that of the embodiment of Figure 4, discussed above. Essentiially, the operations shawn in the fl~wchart of .~
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Figure 5 for the embodiment of Figure 4 are the same for this embodiment, with the only ; the blending operations (indicated at box 526 of Figure 5) being significantly different.
The blending operations of this embodiment will now be described with reference to the :; 5 flow chart of Figure 10.
,,, 5 ' `, In this configuration, non-volatile memory 44 ~urther contains an initial value for the DC current on control line 804, which represerts the position to which additive valve 800 is initially opened. Further, non-volatile memory 44 contains a ratio . of scaled additive pulses to scaled main product pulses for each additive, a variation v~lue 10 below which error, in additive ratios are not corrected and a step value whieh repre~en~, the incremental change made to additive valve positions.
'"';
As indicated at box 850, blending operadons commence with controller 10 opening the additive flow valve to the predefined initial position. Controller 10 then 15 checks to ensuFe that pulses are being received from additive flow meter 140 at box 854.
If pulses are not received, controller 10 executes an emergency shut-d~wn as indicated ~-; at box 858. Providing that pulses are being received, controller 10 counts and scales the ~, pulses from additive flow meter 140 and main product flow meter 116 for a p~e-defined ~ time period and calculates a ratio therebetween as indicated at box 862. The calculated ;-~ 20 ratio is compared to the predefined value at box 866. If the ratio is lawer than the predefined value by more than the variation value, the dc cur~nt to addi~ve flow valve -~ i; 800 is increased by the predefined step value as shown at box 870 and the blending ~ycle continues at bo~ 862.
Alternatively, if the ratio is higher than the predefined value by more than the predefined variation value, as indicated at box 874, the DC culTent to additive valve ~' flow valve 800 is decreased by the predefined step value at box 878 and ~he blending .
, :
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" - 2~90786 cycle con~inues at box 862. Otherwise, if the ratio differs from the predefined value by less than the predefined variation value, as indicated at branch 882, the blending cycle continues at box 862 with no change in the position of additive flow valYe 800.
;J
` 1 5 In a more preferred embodiment, as will be apparent to those of skill in the art, non-volatile memory 44 contains a lookup table of step values for use at boxes 866 i~ and 874, with large step values being employed for large ra~io difference~ and small step ;~; values beinB indicated for small ratio differences. In this mannler, it is contempla~ed that i~ better averall blending ratios will be obtained.
`.J 10 . i ~
;~ The Emergency Shut Down procedur~ ferred to above, is naw described, with reference to the flowchart shown in Figure 11. As indicated at box 900, first the ~'j Enable signals are removed ~om additi~re pumps 132 and main product pump 108. Next, depending upon the current configuration of the blending system, either additive block .~ 15 valves 136 are closed (box 904a) or additive flow ~alves 800 are closed (box 904b) Of injector control signal 712 is removed from injectors 70~ (box 904c). Next, as indicated - ~ at box 908, main product block valve 112 is closed. Finally, an indicative error message ~: is displayed on display 40 and/or is transmit~d through RS485 por~ 36 as shown a~ box ;, 912. Of course, a ~ansaction record is also created indicating the source of the error condition.
It will be appa~ent to those of skill in ~e art that one or more of the abave-described blending system~ can be combined as required. For example, a controller in accordance with the present i~ention may be used with a system comprising a fl~w. .,~
, 25 meter and block valve additive line and a piston injector additi~e line. Similarly, a `'`~3 syste~ comprising a piston injector additivs line aad a streaming additive line may bs employed, or any combination of the abwe-described systems as may be ~equired. As :
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will be apparent to those of skill in the art, any such a combination system will operate witll the appropriate blending operations (as shown in Figurcs 6, 8 and 10) occurring simultaneously, in series or in parallel.
. ~
.~
It will be understood that, while specific preferz~d embodiments have been described aba~e, variations will be apparent to those of skill in the art and should not be -'. considered as departing from the scope of the present invention as defined in the claims appended hereto.
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Claims (18)
1. A method of controlling a blending system process comprising the steps of:
(i) defining a desired ratio of an additive to a main product;
(ii) providing a flow of main product;
(iii) measuring the volume of said main product flow;
(iv) adding a predefined amount of at least one additive to said measured main product flow to substantially achieve said desired ratio;
(v) creating a non-volatile record indicating the time, date, amount and type of additive added in step (iv); and (vi) repeating steps (iii) and (v) as necessary until the process is terminated.
(i) defining a desired ratio of an additive to a main product;
(ii) providing a flow of main product;
(iii) measuring the volume of said main product flow;
(iv) adding a predefined amount of at least one additive to said measured main product flow to substantially achieve said desired ratio;
(v) creating a non-volatile record indicating the time, date, amount and type of additive added in step (iv); and (vi) repeating steps (iii) and (v) as necessary until the process is terminated.
2. The method of claim 1 wherein step (iii) further includes the step of updating a total representing the total measured flow of said main product.
3. The method of claim 2 wherein step (iv) further includes the step of updating a total representing the total amount of additive added.
4. The method of claim 3 wherein step (iv) comprises the steps of:
(i) opening a block valve;
(ii) measuring the flow of said additive through said block valve;
(iii) closing said block valve when the measured flow of additive equals said predefined amount of additive.
(i) opening a block valve;
(ii) measuring the flow of said additive through said block valve;
(iii) closing said block valve when the measured flow of additive equals said predefined amount of additive.
5. The method of claim 3 wherein step (iv) comprises the steps of:
(i) opening a block valve;
(ii) measuring the flow of said additive through said block valve;
(iii) closing said block valve when the measured flow of additive equals said predefined amount of additive, less a stored dribble volume representing the volume of additive dribble occurring after said block valve is closed;
(iv) measuring the actual dribble volume of additive added to said main product after said block valve is closed and updating said stored dribble volume to said actual dribble volume.
(i) opening a block valve;
(ii) measuring the flow of said additive through said block valve;
(iii) closing said block valve when the measured flow of additive equals said predefined amount of additive, less a stored dribble volume representing the volume of additive dribble occurring after said block valve is closed;
(iv) measuring the actual dribble volume of additive added to said main product after said block valve is closed and updating said stored dribble volume to said actual dribble volume.
6. The method of claim 1 wherein step (iv) occurs are a predefined volume of main product flow has been measured.
7. The method of claim 1 wherein predefined amounts of two additives are added to said main product flow.
8. The method of claim 7 wherein said two additives are added substantially simultaneously.
9. The method of claim 7 wherein said two additives are added serially.
10. The method of claim 1 further comprising the step of monitoring the steps of the process and terminating said process upon detecting one or more predefined errors in said monitored steps.
11. The method of claim 10 wherein upon terminating said process a non-volatile record is created indicating the date, time and one or more errors leading to said termination.
12. A controller for an additive blending system to blend at least one additive to a main product at a predefined ratio, comprising:
main product volume measurement means;
program storage means;
non-volatile memory means;
at least one additive supply control means; and processing means responsive to said main product volume measurement means and operating said additive supply control means to provide a volume of additive to said main product volume to achieve said predefined ratio, said processing means creating a record in said non-volatile memory means including the date and time said additive volume was provided and the volume of additive provided.
main product volume measurement means;
program storage means;
non-volatile memory means;
at least one additive supply control means; and processing means responsive to said main product volume measurement means and operating said additive supply control means to provide a volume of additive to said main product volume to achieve said predefined ratio, said processing means creating a record in said non-volatile memory means including the date and time said additive volume was provided and the volume of additive provided.
13. The controller of claim 12 wherein said processing means maintains totals in said non-volatile memory, said totals representing the total volume of main product processed and the total volume of additive provided.
14. The controller of claim 13 further including:
a telecommunications port; and a data-entry means, wherein said predefined ratio is provided from either of said telecommunications port and said data-entry means.
a telecommunications port; and a data-entry means, wherein said predefined ratio is provided from either of said telecommunications port and said data-entry means.
15. The controller of claim 14 further including a data-display means wherein said totals may be displayed on said data-display means in response to commands received from said data-entry means and said totals may be transmitted from said telecommunications port in response to commands received therefrom.
16. The controller of claim 12 wherein said at least one additive supply control means comprises an additive volume measuring means and an additive supply valve, said processing means operating said additive supply valve in response to signals received from said additive volume measuring means.
17. The controller of claim 12 wherein said at least one additive supply control means comprises an additive injector, said processor means operating said additive injector to provide a predefined volume of additive.
18. The controller of claim 12 comprising at least first and second additive supply control means, said first additive supply control means comprising an additive volume measuring means and an additive supply valve and said second additive supply control means comprising an additive injector, said processing means operating said additive supply valve of said first additive supply control means in response to signals received from said additive volume measuring means and said main product volume measurement means and said processor operating said additive injector of said second additive supply control means to provide a predefined volume of additive in response to said signals from said main product volume measurement means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2090786 CA2090786A1 (en) | 1993-03-02 | 1993-03-02 | Additive blending controller |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2090786 CA2090786A1 (en) | 1993-03-02 | 1993-03-02 | Additive blending controller |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2090786A1 true CA2090786A1 (en) | 1994-09-03 |
Family
ID=4151232
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2090786 Abandoned CA2090786A1 (en) | 1993-03-02 | 1993-03-02 | Additive blending controller |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2090786A1 (en) |
-
1993
- 1993-03-02 CA CA 2090786 patent/CA2090786A1/en not_active Abandoned
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20030703 |