BACKGROUND OF THE INVENTION

Technical Field:

This invention relates to additive blending systems, and more particularly to a process for controlling the continuous metering of multiple additives into a product flow in sequence through a single flowmeter.

Background: It is fair to say that all gasolines are created equal. The same holds true for diesels, heating oils, jet fuel and the like. In fact, many petroleum product marketers frequent the same refineries to obtain their product supplies. Each purchases the refiner's "generic" product, and, in turn, resells the product to its customers under its own private label. What usually distinguishes one competitor's brand from another's is the type and amount of additives introduced into the supply of "generic" product to obtain the marketer's branded product. Common gasoline additives include, among other things, octane enhancers, intake valve deposit reducers, port fuel injection cleaners, and dyes. Dyes are also typically added to diesel and jet fuels, along with a multitude of other additives such as de-icers, flow improvers, and anti-pourpoint depressants. Typically, the additives are injected into a product stream as the product is loaded into a tanker truck at the refinery's truck loading rack.

For example, a truck from Company A pulls up to an independent refiner's truck rack to take on a load of unleaded gasoline. According to Company A's recipe for its brand of unleaded gasoline, additives are added to the refiner's store of generic unleaded gasoline as it is pumped into the truck. Next in line is a truck from Company B. Following the same

procedure, Company B is provided with its branded gasoline through the injection of additives as per its own formula. In this manner, one refinery may serve a host of petroleum marketers.

Unfortunately, though, supplying multiple parties with their desired product formulae creates significant obstacles for the refinery operator. Problems encountered when mixing additives with petroleum products include inaccurate measurement, poor data recordation and a lack of precise product and additive control, coupled with increasingly severe regulatory requirements, high cost factors, and potential legal liability. The current industry standard for additizing petroleum products is

"pulse based" additive injection. This type of system, however, is inherently inaccurate and extremely susceptible to error induced by adverse weather conditions, varied pump pressures

and higher product flow rates. The pulse system uses a solenoid actuated two-way valve that cycles at a set interval to inject additive into a product stream during the loading process. A standard system might be set to cycle once for every forty gallons of product loaded. The solenoid is actuated for only half of the cycle. When the solenoid is activated, the pressure in the additive line forces the additive already in the injection cylinder into the product stream. When the solenoid is deactivated, the valve openings reverse and a second measure of additive is forced into the stream using the pressure of the additive supply pump.

Since the pulse based systems operate on a cycle, two criteria must be met to insure proper additization. First, the number of gallons being loaded must be exactly divisible by the cycle interval, such as forty gallons. Second, the loading conditions (i.e., flow rate, additive viscosity, weather conditions, pump pressures) must allow for a sufficient pressure differential so that a full measure of additive flows into the injection chamber before the solenoid beings the next phase of the cycle. If both criterion are not met, the load cannot contain the proper amount of additive. This is the usual case. Upon random sampling at an average truck loading facility, it was discovered that only one in forty loads will be evenly

divisible by forty gallons. Thus, only 2.5% of product loads meet the first condition of prope additization. This group of properly additized loads is smaller still during cold periods whe the viscosity of the additive is higher, or is eliminated completely when product flow rates ar high enough to prevent a full measure of additive from entering the injection chamber. The periodic, pulse based systems also fail to allow for the use of the same flowmete to measure the sequential injection of multiple additives. This inadequacy increases hardwar costs to terminalling operators. The required complexity of the systems is also a drawbac in that increased complexity lends itself to maintenance and repair problems.

In an attempt to address the problems created by high flow rates and additive viscosit changes, the industry has been provided with an injection system utilizing a solenoid activate valve and a positive displacement gear-meter which measures the volume of additive bein transferred to the product. Although an improvement over the original injection technique the gear-meter system is still a pulse based system. As such it is prone to err whenever th number of gallons in the load is not divisible by the pulse increment. Furthermore, standar accuracy for gear meters is normally reported as +/- 0.5% within the flow range of the meter. The accuracy of the meter is established at a constant flow of material through the mete within its stated accuracy range (usually 80% of maximum flow). Error becomes muc greater in a gear meter system at the low flow rates often encountered in additive injectio systems. Most gear meters have a turndown ratio of 5:1 which means they are incapable o measuring flows of slow-moving viscous liquids, like some additives. Additionally, becaus the stated meter accuracy is measured at a constant flow in a range where the meters are mos accurate, the gear meters are less accurate when measuring the pulsating flow of additiv injection. Clearly, a gear meter injection system is not a solution to accurate, reliable additiv

injection.

Under current practice more error is induced by the necessity of flushing the loading line from the additive injection port to the nozzle of the load arm after each loading procedure.

The flush is designed to make sure that the next load contains only the appropriate type of additive; therefore, at the end of a loading run, pure unadditized product is circulated through the loading lines to clear away all additives present. This flush quantity varies from tiiirty to seventy gallons of product at different loading facilities. On average, the flush volume is fifty gallons of product. What this means in practical terms is that the first fifty gallons of each and every load contains no additive whatsoever, skewing the error farther toward constant under-additization. Many loading facilities compensate for flushing error by over additizing the product

and increasing the additive dose per stroke of the injector. This is done to ensure that a minimum batch size will have 0% error. As a result, all batch loads greater than the minimum batch size receive excess additive, as much as 17%. This is an expensive solution costing hundreds of thousands of dollars annually. Still another problem with current systems is ineffectual additive blending. The additives are merely pushed through a small port into the main product stream immediately prior to the flow of the stream into the truck or transport tank. Without thorough mixing the additives either settle to the bottom of the load or float as a layer on top of the product, depending upon the densities of the product and additives. All these errors inherent in the current practice of additive injection grow in importance when considering the contemporary climate of stringent environmental based regulatory controls and tight corporate fiscal policies. On the horizon is mandatory detergent additization combined with requirements of detailed accounting and record keeping, regular equipment calibration, preparation of transfer documents, and maintenance of quality control and assurance procedures. The current industry systems which experience high additization errors

and provide no load-by-load additization data and communication capabilities do not measure up. Moreover, the shortcomings of present additive injection technology continue to cost the petroleum industry millions of dollars annually in additive "giveaways" through the over additization of products to ensure a minimum additive blend ratio. Although the above discussion pertains to the use of additive injection systems in the petroleum industry, and in truck loading racks in particular, it should be understood that the

present invention may be practiced in any circumstance in which one or more additives are sought to be introduced into a product stream.

SUMMARY OF THE INVENTION

It is thus an object of the present invention to provide a process for controlling the continuous metering of multiple additives into a product flow in sequence through a single flowmeter.

An additional object of the invention is to provide a process and apparatus for measuring and managing the introduction of one or more additives into a product stream wherein the flow of additives is continuously and precisely measured, monitored, and controlled so that a higher product quality is consistently achieved.

It is a further object of the invention to provide a process and apparatus for allowing real time accounting of additive introduction per batch of product and communication of such

accounting information at the transfer site, improving data recordation and data transfer for better accountability and legal compliance.

Another object of the invention is to furnish a unique, self-cleaning blend manifold and valve assembly of modular construction that is small and easy to install at a loading island without a great deal of modification or support, thus reducing installation costs, and that permits the continuous flow of multiple additives into the product stream.

Yet another object of the invention is to supply an additive management system wherein the additives are, prior to introduction into the product stream, premixed with a product slipstream to dilute the additive and promote a thorough blending of the product and additive. An additional object of the invention is to provide an additive management system which utilizes an additive distribution nozzle to facilitate a uniform and continuous dispersion of additive, ensuring that a complete blending of additives and product is achieved prior to the additized product being loaded into a transport vehicle.

A still further object of the invention is to provide an additive management system which utilizes an additive loading line flushing feature to make certain that no additive residue

is left in the loading lines, thus assuring precise subsequent load admixture, and which controls, accounts and reports such practice.

These and other objects and advantages are achieved by the present invention, which includes a process for controlling the continuous metering of multiple additives into a product flow in sequence through a single flowmeter. The process includes continuously measuring the rate of a product flow. In response to the detected product flow rate, a first additive is

routed through the flowmeter via an additive flow path such that an appropriate amount of the first additive is continuously provided to the product flow at a user defined blend ratio. After the proper amount of first additive has been provided, the additive flow path is flushed with a portion of product. After flushing of the additive flow path, a second additive may be directed through the same flowmeter via the same additive flow path.

In the preferred embodiment of the process of the invention, a product slipstream is passed to a flow control assembly or manifold, the flow control assembly having two or more inlets for receiving a flow of additive and being adapted to direct the product slipstream and the additive to a flowmeter. Again, the rate of a product flow is continuously measured, and, in response to the product flow rate, a flow of additive from one of the inlets is released into the flow control assembly such that an appropriate amount of additive is continuously provided by the flow control assembly to the flowmeter at a user defined blend ratio. The additive flow is returned to the flow control assembly after passage through the flowmeter for mixing with the product slipstream to obtain an additized slipstream. The additized slipstream is then directed to the main product flow. After the flow of additive is stopped, the product slipstream is passed through the flow control assembly to the flowmeter and further into the product flow completely flushing the additive from its flow path. At this point a different additive may be released into the flow control assembly for routing to the flowmeter, mixing with the slipstream, and delivery to the main product flow.

A better understanding of the invention, and the objects thereof, will be obtained fro the following description, taken in conjunction with the attached drawings. As furthe disclosed hereunder, the present invention fulfills the need for more sophisticated and accurat additive measurement and monitoring, improved control, improved data acquisition, an compliance with stricter regulatory schemes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the relation of certain components of the invention

FIG. 2 is a plan view of the additive blending unit as configured in a one pas arrangement.

FIG. 3 is a plan view of the initial stage of operation as configured in a one pas

arrangement.

FIG. 4 is a plan view of the additive blending mode as configured in a one pas

arrangement.

FIG. 5 is a plan view of the additive flushing mode as configured in a one pas arrangement. FIG. 6 is a plan view of the additive blending unit as configured in a two pas arrangement.

FIG. 7a is a block diagram showing the relation of additive blending units as they might be arranged at a product loading facility.

FIG. 7b is a block diagram showing the relation of the system control components to the additive blending units.

FIG. 8 is a plan view of the system control components.

FIG. 9a is a side plan view of the blend manifold.

FIG. 9b is a top plan view of the blend manifold.

FIG. 9c is a bottom plan view of the blend manifold. FIG. 9d is an end plan view of the blend/flush block portion of the blend manifold.

FIG. 9e is an end plan view of the end cap portion of the blend manifold.

FIG. 9f is another top plan view of the blend manifold showing the channel structure

of the manifold.

FIG. 10a is a cross-sectional view of the blend manifold taken along the line lOa-lOa of FIG. 9a.

FIG. 10b is a cross-sectional view of the blend manifold taken along the line lOb-lOb of FIG. 9a. FIG. 10c is a cross-sectional view of the blend manifold taken along the line lOc-lOc of FIG. 9a.

FIG. 1 la is a longitudinal section view of the blend manifold taken along the line 11a- 11a of FIG. 9f.

FIG. 1 lb is a longitudinal section view of the blend manifold taken along the line 11b- l ib of FIG. 9f.

FIG. 1 lc is a longitudinal section view of the blend manifold taken along the line 11c- 11c of FIG. 9f.

FIG. 12 is a side plan view, akin to FIG. 9a, of the blend manifold shown as expanded to accommodate additional additive feed lines. FIG. 13 is a plan view of the distribution nozzle assembly and its relation to the additive blending unit.

FIG. 14 is a plan view of the distribution nozzle assembly as shown in a longitudinal section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the additive blending unit is generally indicated by the element number 30. Integral to additive blending unit 30 are a mass flowmeter for measuring the flow ^f of additives and a throttling control valve (not shown in FIG. 1) for controlling the flow o additive through the mass flowmeter. The highly accurate mass flowmeter measurement is certified for custody transfer by the United States Department of Commerce. Customarily, there is installed one additive blending unit 30 per product loading riser. Additive blending unit 30 is adapted to receive a flow of additive and includes a flow control assembly which may be constructed of a modular, manifold design and which allows for several additives to be measured by one mass flowmeter. Multiple additives may also be delivered simultaneously, and additive blending unit 30 may be easily expanded to accommodate the installation of additional additive feed lines.

Additive blendmg unit 30 is linked to a distribution nozzle assembly 80. The distribution nozzle assembly 80 ensures a thorough blending of product and additive to provide a homogeneously additized product. This is accomplished through the unique design of distribution nozzle assembly 80. The assembly supplies a slipstream of product to additive blending unit 30 so that the injected additive may be mixed with the product slipstream prior to its introduction into the main product flow. This blending effect of the premixing feature is augmented by the turbulent introduction of the additized slipstream into the product flow. Turbulence is created in the main product flow pipeline at the point where the additized slipstream returns to the main product flow. The turbulence is developed by a bullet-shaped nozzle (not shown in FIG. 1) placed in the main product stream. The passage of product through and around the nozzle generates a wave action which functions to encourage the thorough blending of the additized product slipstream with the main product flow.

Distribution nozzle assembly 80 also facilitates the flushing of additive blending uni

30 so that no additive residue is left in the unit at the end of a loading cycle. When in its flushing mode the product slipstream supplied by distribution nozzle assembly 80 is rerouted to flush and clear the mass flowmeter, throttling control valve and additive metering runs (not shown in FIG. 1) in preparation for the blending of another additive with the product. The flushing of the flowmeter, throttling control valve and metering runs with pure produc provides the capability to use one common flowmeter and control valve for the delivery o several different additives in sequence without commingling or cross-contamination o additives. In addition, the flush sequence, performed near the end of each batch load, ensures that all measured additive is delivered to the loaded vehicle and does not remain in the

terminal metering or piping system. Consequently, the reporting accuracy of additive quantity delivered to the transported batch of product is improved. Thus, a measurement and reporting deficiency that occurs in current systems is eliminated, as the metered additive does not remain as line fill to the transport vehicle but is completely flushed to the transport vehicle, ensuring that all metered additive is fully and accounted for and delivered to the transport vehicle.

Additive blending unit 30 is controlled by STD-Bus control unit 60, which comprises an industrial 80486-CPU base computer system. Control unit 60 regulates a real time ratio blending process by continuously receiving product flow rate measurements, reading additive select and blending ratio user input data, and, in response to the product flow measurements, controlling the flow of additive by manipulation of the throttling control valve such that the appropriate additive is continuously provided at the user defined blend ratio. Control unit 60 may be configured to manage a number of additive blending units, communicating with each unit's mass flowmeter and throttling control valve and recording process data such as flow rate, additive density, additive temperature and additive totalization figures. Control unit 60 also stores an intermediary database in a battery backed static RAM to prevent information

loss due to power outages.

Control unit 60 is adapted to connect to an additive system host 10. Additive syste host 10 comprises a 80486-CPU based personal computer which is capable of communicatin with multiple control units. Host unit 60 maintains additive mass balance accounting data an generates transfer documents to fulfill 40 CFR Part 80 requirements and is designed t accurately account in mass quantities for all additives injected. Host unit 60 can als communicate with various terminal automation systems on virtually any platform or desire protocol for total system and quality control automation, including communication with an off site PC via a modem. The advanced communication capabilities of host unit 60 provides th ability to interface with more sophisticated and capable technology advances as they ar implemented in the terminal. The modem connection allows the user to monitor syste performance and assist in troubleshooting additization problems, making errors detectable o a load by load basis. In this manner, additization errors can be identified and correcte quickly and inexpensively. Before discussing FIG. 2-6 it should be explained that the views therein shown an described are functional, plan views of the invention given to illustrate the invention and th certain configurations and flow patterns made available in accordance with the teachings o the invention. As will be seen with respect to FIG. 9-12, the particular configurations an controlled flow patterns desired to be implemented in a specific circumstance, taking int account individual terminal requirements, may be realized through the use of hardware adapte to carry out such flow routines.

Turning now to FIG. 2, additive blending unit 30 is shown as configured in a on pass/four additive arrangement. Rectangular dotted line 31 denotes an explosion proof housin which surrounds the sensitive components of additive blending unit 30. Additive feed line 18a-d run from additive storage tanks to a point outside explosion proof housing 31 wher

they connect to additive line unit cut-off valves 12a-d, respectively. Cut-off valves 12a-d may be manually closed in case of maintenance or emergency. Additive feed lines 18a-d are also provided with strainers 13a-d downstream from cut-off valves 12a-d. The strainers remove particulate matter and debris from the additive supply prior to its entry into additive blending

unit 30.

As additive feed lines 18a-d enter additive blending unit 30, additive flow is restricted to a downstream direction by additive line/blending unit check valves 15a-d. The flow of additive from additive feed lines 18a-d is managed by additive line solenoid control valves

20a-d. Each solenoid control valve 20a-d is electrically coupled by A/C trunk line 19a to a source of alternating current which is manipulated by control unit 60 as appropriate during the

course of a loading procedure. Both alternating current and direct current are provided to additive blending unit 30 by trunk lines 19 and 16, respectively, which emanate from control unit 60. Downstream from solenoid control valves 20a-d, additive feed lines 18a-d mate with a metering run 24. For purposes of illustration, metering run 24 is shown in FIG. 2 to be rectangular in shape. After additive select and blend ratio information have been input by a user such that there is established an additive flow through one of additive feed lines 18a-d into metering run 24, the additive flows through metering run 24 toward mass flowmeter 35. The additive is restrained from flowing in the direction opposite mass flowmeter 35 by metering run check valve 23.

Mass flowmeter 35 is of the type of dynamic massmeters which utilize Coriolis technology as the working principle. On a very general level, using Coriolis technology, the mass of a liquid flow can be determined from the degree of deflection caused in a oscillating tube by the passage of the liquid flow. The preferred mass flowmeter for use with the present invention is the mass flowmeter (I/A SERIES) manufactured by The Foxboro Company. This

particular mass flowmeter has a single continuous flowtube, consisting of two parallel positioned loops, which is excitated in a drive motion at its natural frequency. The tube arrangement is oriented ninety degrees to metering run 24. As soon as additive passes through the flowtube a reactive force is created. The motion caused by this Coriolis force oscillates at the same frequency and is ninety degrees out of phase from the drive motion. Two sensors are used to detect the Coriolis motion. At one of the sensors the Coriolis motion lags the drive motion, and at the other sensor the Coriolis motion leads the drive motion.

Consequently, a sum of the outputs from the two sensors separates the Coriolis motion from the drive components to produce a signal that, when synchronously demodulated, is relatively noise free and exactly proportional to the mass flow rate. Mass flowmeter 35 is electrically coupled by D/C trunk line 16b to a source of direct current which is manipulated by control unit 60 as appropriate during the course of a loading procedure.

Additive flow through mass flowmeter 35 is regulated by throttling control valve 29. Throttling control valve 29 is a sensitive, electrically actuated ball valve. It is electrically coupled by D/C trunk line 16a to a source of direct current and by A/C trunk line 19a to a source of alternating current, which currents are manipulated by control unit 60 as appropriate during the course of a loading procedure. As throttling control valve 29 is commanded to open by control unit 60, additive flows through mass flowmeter 35 where it is measured. It then passes through throttling control valve 29 and further downstream through metering run 24.

From distribution nozzle assembly 80 to metering run 24 runs product input feed 50. Distribution nozzle assembly 80 generates a product slipstream which proceeds through product input feed 50 to additive blending unit 30. Near the junction of product input feed 50 and additive blending unit 30 there are positioned two solenoid control valves 26 and 27, more particularly described as metering run flush cycle solenoid control valve 26 and metering

run blend cycle solenoid control valve 27. Both are electrically connected by A C trunk line

19b to a source of alternating current managed by control unit 60. To provide the product slipstream for use in the blending process, blend cycle solenoid control valve 27 is maintained in an open position while flush cycle solenoid control valve 26 is kept closed. This forces the product slipstream coming from product input feed 50 through blend cycle solenoid control valve 27 to mix with the additive coursing through metering run 24 downstream of throttling control valve 29. From the point of combination of the product slipstream and additive, there runs to distribution nozzle assembly 80 an additized slipstream output feed 52. The additized slipstream flows through additized slipstream output feed 52 to distribution nozzle assembly

80 where it is injected into the main product flow. To provide the product slipstream for use

in flushing additive residue from metering run 24 after additive line solenoid control valves 20a-d have been closed, flush cycle solenoid control valve 26 is maintained in an open position while blend cycle solenoid control valve 27 is closed. By this action the product slipstream coming from distribution nozzle assembly 80 is directed through metering run check valve 23 so that a pure product flow is created through additive blending unit 30. As metering run check valve 23 is positioned upstream of the point where additive feed lines 18a-d intersect with metering run 24, the product slipstream flushes all additive remaining in metering run 24 through mass flowmeter 35 and throttling control valve 29 to distribution nozzle assembly 80. A test/calibration port 54 is located adjacent to additized slipstream output feed 52.

Figures 3, 4, and 5 show in greater detail the flow configuration of the present invention as configured in a one pass arrangement and the utilization of the product slipstream to facilitate the blending of the product and additive and the end-load flushing of metering run 24. As seen in each of these figures, distribution nozzle assembly 80 is coupled at its forward and aft flanged ends 87a and 87b to a product loading line 83. As the product flows through

distribution nozzle assembly 80, a portion of the product flow is captured by the aft end o nozzle bullet 90. The captured product, forming a product slipstream, is transported to additive blending unit 30 via product input feed 50. A feed line cut-off valve 92b is provided along product input feed 50 for manual control when desired. Additized product output feed 52 runs from metering run 24 to distribution nozzle assembly 80 and is also furnished with a feed line cut-off valve 92a. Additized slipstream output feed 52 has its additized slipstream outlet positioned at the forward end of nozzle bullet 90.

FIG. 3 shows the flow configuration at a point which may be considered the first stage of system operation. Product is flowing through loading line 83, and a product slipstream has been generated by distribution nozzle assembly 80. Specifically, the aft end of nozzle bullet 90 has captured an amount of the product flowing through loading line 83 to form a product slipstream which has travelled through product input feed 50 and an open feed line cut-off valve 92b to additive blending unit 30. As shown in this view, both flush cycle solenoid control valve 26 and blend cycle solenoid control valve 27 are in a closed position. This is for purposes of illustration.

FIG. 4 demonstrates the blend cycle of the invention. Based upon user input to host unit 10, control unit 60 has actuated additive line solenoid control valve 20b to initiate a flow of additive to metering run 24. The additive is prevented from back-flowing through metering run 24 by metering run check valve 23. In response to its receipt of product flow rate data, control unit 60 has also actuated throttling control valve 29 such that the appropriate amount of additive has been allowed to flow through mass flowmeter 35 and throttling control valve 29 downstream to a point near blend cycle solenoid control valve 27. It is here where the additive meets the product slipstream generated by distribution nozzle assembly 80, for in their normal positions flush cycle solenoid control valve 26 is closed whereas blend cycle solenoid control valve 27 is open. Thus, until flush cycle solenoid control valve 26 or blend cycle

solenoid control valve 27 is actuated by control unit 60, additive blending unit 30 is configured to provide the product slipstream for the blending cycle of the invention.. The additive and product slipstream commingle at the outflow point of blend cycle solenoid control valve 27 and, together as an additized slipstream, pass through additized product output feed 52 to the forward outlet of nozzle bullet 90.

Referring now to FIG. 5, the end-load flushing feature of the invention is illustrated.

At this point of the loading procedure control unit 60 has deactivated additive line solenoid control valve 20b so that the flow of additive into metering run 24 has been stopped. To clear metering run 24 and additized product output feed 52 of additive residue prior to the initiation of a subsequent loading procedure, control unit 60 actuates blending cycle solenoid control valve 27 into a closed position. Conversely, flushing cycle solenoid control valve 26 is opened upon actuation by control unit 60. In this way, the product slipstream provided by distribution nozzle assembly 80 is directed toward and through metering run check valve 23, eventually pushing all additive remaining in metering run 24 and additized product output feed 52 out the forward output end of nozzle bullet 90. Metering run 24 is left filled with unadditized product. Through user input of control tuning parameters into host unit 10, the amount of static product contained in metering run 24 at the beginning of a loading procedure, known as the product flush quantity, is accounted for and considered by both host unit 10 and control unit 60 in the measurement and management of the additive introduction. FIG. 6 shows a plan view of additive blending unit 30 as configured in a two pass/four additive arrangement. It should be understood that inasmuch as it is constructed in a modular fashion employing a unique, expandable blend manifold, as is described more fully below, additive blending unit 30 may be arranged in an almost limitless number of configurations. From a one pass/one additive arrangement to a one pass/six additive arrangement and up to a two pass/six additive arrangement or more, the flexibility and expandability of the present

invention is one of its hallmarks. As shown in FIG. 6, the two pass/four additive arrangemen is structurally similar to the one pass/four additive arrangement save and except for th inclusion of branched additive feed lines which flow into parallel metering runs, each meterin run having its own mass flowmeter and throttling control valve. For purposes of illustration, your attention is once again directed to additive feed line

18a-d of FIG. 6. In the two pass/four additive arrangement additive feed lines 18a-d eac branch at a point downstream of additive line/blending unit check valves 15a-d. A first branc of additive feed lines 18a-d is routed to a first additive line solenoid control valve 20a-d(l).

A second branch of additive feed lines 18a-d is directed to a second additive line solenoi control valve 20a-d(2). The outflow from each additive line solenoid control valve is directe to its respective metering run, i.e. flow from additive line solenoid control valves 20a-d(l) is directed to metering run 24a while flow from additive line solenoid control valves 20a-d(2) is sent to metering run 24b. Metering runs 24a and 24b are provided with mass flowmeters 35a and 35b, respectively, along with throttling control valves 29a and 29b. Each metering run is also supplied with a metering run check valve (23 a and 23b) upstream of additive feed lines 18a-d.

In this two pass arrangement, two additives may be simultaneously injected into a product stream. Again, the system user inputs additive select and blend ratio data to host unit 10 along with other data variables as more fully discussed hereafter. When a product flow is initiated, control unit 60 actuates the two additive line solenoid control valves associated with the chosen additives to initiate a flow of additive to each respective metering run. For example, should the additives affiliated with additive feed lines 18a and 18b be selected, additive line solenoid control valve 20a(l) is actuated so that it assumes an open position while additive line solenoid control valve 20a(2) remains in its normal closed state. Accordingly, the additive from additive feed line 18a flows into metering run 24a. In a

opposite fashion, additive line solenoid control valve 20b(l) is kept closed while additive line solenoid control valve 20b(2) is energized to an open position so that the additive from additive feed line 18b flows to metering run 24b. The additives are prevented from back- flowing through metering runs 24a and 24b by metering run check valves 23a-b. In response to its receipt of product flow rate data, control unit 60 actuates throttling control valves 29a-b such that the appropriate amount of additive is allowed to flow through mass flowmeters 35a-b and throttling control valves 29a-b downstream to a point where metering runs 24a and 24b converge to form a single flow. The combined additive flow is premixed with the product slipstream provided by the distribution nozzle assembly 80 and the additized product slipstream is injected into the main product flow via the forward outlet of nozzle bullet 90 as

in the one pass arrangement described above.

In the FIG. 6 arrangement, both additive runs are managed through control unit 60 as prompted by host unit 10. Additive select and blend ratio user input signals, along with other input information, set the parameters for control unit 60 to manipulate the appropriate additive line solenoid control valves 20a-d and to continuously adjust throttling control valves 29a-b in response to measured product flow rate data such that the proper additization is achieved.

Referring now to FIG. 7a and 7b, there is shown (1) a block diagram of the additive blending units as they might be arranged at a product terminalling facility and (2) the relation of the system control components to the additive blending units. Each loading island is equipped with a plurality of loading risers. The loading risers are the conduits through which product is carried from a storage tank or pipeline for delivery to a tanker truck or other hauling means. In the case of tanker trucks, the rig's trailer is generally provided with three or four gasoline holding compartments. Thus, the truck may take on a load consisting of, for example, regular unleaded gasoline, premium unleaded gasoline and diesel at the same time. To manage this, each loading island is provided with a riser corresponding to a particular

product, i.e. riser #1 may be dedicated to unleaded gasoline of 87 octane, riser #2 to premium gasoline of 89 octane, riser #3 to high octane (92) gasoline, riser #4 to diesel, riser #5 to kerosine, and so on. Of course, the number and arrangement of product risers is completely discretionary and is modifiable without result to the objects of this invention. Illustrated in FIG. 7a and 7b is a two additive system. The additive feed lines 18a-b of the additive blending units of each loading island are routed to connect to their appropriate additive storage tank 37a-b, which are provided with tank level gauges 34a-b. Additive supply pumps 36a-b are furnished to aid in the transmission of additive through additive feed lines

18a-b. Each additive blending unit is electrically connected to a control unit 60a-c. A control unit 60 is provided for each loading island, although this is not mandatory since each control unit can manage up to twelve introduction points. Control units 60a-c are electrically connected to host unit 10, and host unit 10 may be, in turn, connected to a terminal automation system host 95 for full integration into the terminal's computerized control system. Host unit 10 is designed so as to be contactable through a telephone modem connection 97 and can generate custody transfer documents for printing off transfer document printer 99.

FIG. 8 represents a plan view of the system control components. Additive host unit 10 comprises, preferably, an 80486 central processing unit 110a, a telephone modem 110c, a 110-120 VAC power supply 110b, and a cooling fan HOd. Host unit 10 provides user interface functions, allowing the user to configure the system control components by controlling ttining and system parameters. In addition to factoring input related to product flush quantities, product meter correction factors, throttle valve control boundaries and blend ratios, host unit 10 is capable of utilizing input respecting minimum batch quantities, minimum and maximum flow rates, and additive and product nomenclature to produce detailed mass balance accounting reports, including individual additive inventories, terminal additive inventories, and individual additive transaction reports. From the input information and data

received and digested from the product flowmeters and mass flowmeters, host unit 10 can reconcile and report additive and terminal inventory in a form providing additive identification, beginning inventory, receipts or transfers or adjustments to inventory, throughput, ending inventory, average daily usage, and average turnover rate. Host unit 10 can also track by product name and blend unit number the volume of product additized over time, the desired ratio of additization versus the actual ratio achieved, the percent of ratio error and the average load size encountered. The number of critical and non-critical additive delivery errors may also be reported by blend unit number. The user may also use the input feature of host unit

10 to engraft password protection into the system and enter reconfiguration data based upon changes in blend manifold setup (described below).

Telephone modem 110c allows for remote access to host unit 10 to update control software, to perform statistical process control analysis, and to provide remote alarms and out- of-spec notifications based upon additive blending problems, density fluctuations or the like. All data files can be remotely accessed for report generation. Host unit 10 stores and maintains historical data, including density and temperature tracking for periodic review. Host unit 10 may be connected to the user's network to allow further integration into the terminal automation system and easy access to the additive database and historical information.

Control unit management is also a function of host unit 10 which provides data and network management of control units 60, including errata logging and failure tracking. Control unit 60 controls the real time ratio blending process by being adapted to receive product flow rate measurements from standard flowmeters common to the industry, and, in response to the detected product flow rate, continuously adjusting throttling control valve 29 such that the appropriate amount of additive is injected into the main product flow. Control unit 60 preferably consists of two central processing units ~ one to control the additive introduction process, a 80486 CPU, and one to manage communications, a V40 286. This

multiproccessor architecture allows for high speed real time feedback control of th introduction process and for a highly accurate and consistent blending of additive and product

Communications between control unit 60 and host unit 10 are via standard multidrop seria communications. If desired, control unit 60 can also be integrated into the termina automation system without host unit 10. All process data collected by control unit 60 i readily available to host unit 10 or other user defined systems.

Control unit 60 is also extremely flexible and expandable as it utilizes standard centra processing units, can be DOS based, and all code is written in C. These features make it ver easy to adapt control unit 60 to unique applications. The user is not locked into hardware/hardcode specific platform. It is adaptable to an expansion of the number an configuration of additive injectors and types. Moreover, expansions or adaptations not covere in the configuration file can be custom coded according to the user's specifications.

Preferably, control unit 60 should be operable at temperatures ranging from 0° C t 80° C and have a storage temperature of -20° C to 80° C. Electrical specifications include supply voltage of 110-125 VAC fused to 55-60 Hz. Control unit 60 should be isolated 25 VDC to chassis ground and have a power requirement of about 5 amps. Preferably, the 8048 CPU will have a clock speed of 33 MHz and memory of at least 4 Mb. A real time cloc should be provided with a battery backup, time of day and date. Memory storage should als include a battery backup SRAM to hold crucial data, programs and configurations during time of power loss of up to 60 days. The number of inputs and outputs of control unit 60 will var depending upon the application; but the following data are typical for each type o input/output. There should generally be provided twelve discrete, optically isolated, output having 120 VAC each and a 3 amp maximum, four discrete outputs having 60 VDC each an a 3 amp maximum, also optically isolated, and TTL level digital outputs. Discrete input should include a 120 VAC, optically isolated input, four 16 VDC inputs, also opticall

24 isolated, and a high speed counter TTL level DC to 8 MHz. Four analog inputs rated to 20 mA are preferably included, together with four similarly configured analog outputs. Communications can be run on RS-232/485/422 at 300 to 19,200 baud.

Still with respect to FIG. 8, in its preferred configuration, control unit 60 includes a housing having an 110-125 VAC power supply input 160d. Inside the housing is fan 160e, together with two mass flowmeter transmitters 160a(l) and 160a(2), the central processing unit 160b, and an STD-Bus 160c. The various computer cards may be placed inside the control unit housing in a standard card rack. In the normal arrangement, there is positioned a CPU card, a battery backed static RAM, a slave I/O or communications board, a digital I/O board, a counter card and an analog output card. The digital I/O board controls the opening and

closing of all the solenoid valves while the analog output card controls all throttling control valves connected to the control unit. The counter card receives and digests product flow data from which additive control parameters are determined. The counter card is connected to a circuit board which allows for connection to the product flowmeter without interference to the flowmeter or counter card. An optical isolator is also provided within the control unit housing. It electrically isolates the computer equipment from electrical interference within or outside of the unit.

Figures 9a-f, lOa-c, l la-c, and 12 show the unique blend manifold 40 which may be employed in connection with the blending and flushing of product and additive, functioning as the flow control assembly of the invention. Blend manifold 40 provides a mechanism by which the process for controlling the continuous metering of multiple additives into a product stream in sequence through a single flowmeter is achieved. Blend manifold 40 is a modular unit comprising three sections that permits the continuous flow of three different additives into the product stream. The first section, termed the blend/flush block 42, is of a generally square shape. Blend/flush block 42 houses an original blend/flush valve assembly (discussed below),

a component that allows for this in-line manifold to feed pure additive to the product. The valve assembly flushes the flow channels with pure product at the end of a load and cycles to generate a pressure wave throughout blend manifold 40 that "scrubs" even viscous additives from the manifold walls. Blend/flush block 42 is connected to an additive manifold block 44. Additive manifold block 44 has two flow channels, indicated as 124a and 124b, so that two additives can be put into the product stream simultaneously. At the end of additive manifold block 44 opposite of blend/flush block 42 is end cap 46. This component routes the additive to the mass flowmeters 35 and throttling control valves 29. An O-ring seat 165 is provided between blend/flush block 42 and manifold block 44, preferably for a #20 TEFLON O-ring. A second O-ring seat is located between manifold block 44 and end cap 46 for a #14 TEFLON O-ring. The blend manifold 40 illustrated in the drawings is configured for a two pass/three additive arrangement. It should be understood, however, that considering the flexible and modular nature of blend manifold 40, its configuration may be adapted to fill a variety of additive introduction demands and requirements. An expanded blend manifold 40 is shown in FIG. 12 to consist of two manifold blocks 44 such that the additive introduction capacity of blend manifold 40, in terms of the number of additives capable of introduction, is doubled.

The three sections of blend manifold 40 are held together by three through-bolts or nut and bolt assemblies, one centered at the top of blend manifold 40, indicated as element number 120, and two disposed at the lower end of blend manifold 40 on opposite sides thereof, indicated as 121 and 122. Blend manifold 40 itself is small. For a three additive system, the entire manifold is only nine inches long, four inches wide and three inches thick. This allows for easy installation at the loading island without a great deal of modification to existing structures.

26

Describing now in more detail the architecture of blend manifold 40, blend/flush block 42 is provided on its top surface with two valve cavities 43a-b. Valve cavity 43a is associated with the blending feature of the invention while valve cavity 43b is identified with the flushing mode. When installed, valve cavities 43a-b will be contiguous to the previously described metering run solenoid control valves 26 and 27. Blend cycle solenoid control valve 27 sits atop valve cavity 43a and flush cycle solenoid control valve 26 is positioned above valve cavity 43b. Located within blend/flush block 42 are several channelled inputs, outputs and headers. Running perpendicular to throughbolts 120, 121 and 122 are a product supply header

135, a metering run return 139, and a flush header 137. Product supply header 135 has a plugged bore hole on the near side (as shown in FIG. 9a-f) of blend/flush block 44 and runs

nearly the width of said block 44. Connecting to product supply header 135 at approximately its midpoint is product input channel 132, which originates on the underside of blend/flush block 44. Metering run return 139 runs the width of blend/flush block 44 and is generally centered beneath valve cavities 43a-b. It is plugged at each of its ends and connects to an output channel 130 directed to distribution nozzle assembly 80. Further toward manifold block 44 is blend/flush header 137. It too has a plugged bore hole on the near side of blend flush block 44 and runs nearly the width of said block 44. Two outlets from flush header 137 connect to metering runs 124a and 124b, respectively, through one-way metering run cartridge check valves 140a-b. Valve cavity 43a is channelled to communicate with product supply header 135 and metering run return 139. Valve cavity 43b is likewise channelled to communicate with product supply header 135, but is further channelled to connect to metering run 124b at a point upstream of flush header 137.

With respect to manifold block 44, it is, like blend/flush block 42, provided on its top surface with a plurality of valve cavities. The valve cavities are positioned in two rows 41 and 45 -- the valve cavities of row 41 being located at points above metering run 124a while

27 the valve cavities of row 45 are located at similar points above metering run 124b. When installed, the valve cavities of rows 41 and 45 will be contiguous to the previously described additive line solenoid control valves 20. If all of the valve cavities of rows 41 and 45 are not utilized, such unused cavities may be furnished with an appropriately sized, threaded hex-nut plug. In their normal state, all additive line solenoid control valves assume a closed position. Manifold block 44 is further supplied with three additive headers 125 which run perpendicular to throughbolts 120, 121 and 122. Each additive header 125 has a plugged bore hole on the near side (as shown in FIG. 9a-f) of blend/flush block 44 and runs to a point beneath metering run 124a. An additive input channel 127, originating on the underside of the blend manifold, is provided for each additive header 125 and connects thereto at a point generally in the center of additive header 125. When installed, the previously discussed additive feed lines 18 may each be connected to a respective additive input channel 127. Each of the valve cavities of row 41 is channelled at one point to its respective additive supply header 125 and at another point to metering run 124a. In a similar fashion, each of the valve cavities of row 45 is channelled to its respective additive supply header 125. As opposed to the valve cavities of row 41, however, the valve cavities of row 45 are further channelled to metering run 124b.

As for the flow configuration of blend manifold 40, when in the typical blending mode pure product is supplied to product supply header 135 through product input channel 132. It should be noted that the product supplied to product supply header 135 is provided by the product slipstream generated by distribution nozzle assembly 80. When in the blending mode, blend cycle solenoid control valve 27 sitting atop valve cavity 43a is in its normally open position. In other words, unless blend cycle solenoid control valve 27 is actuated upon command from control unit 60, it assumes an open attitude such that product from product supply header 135 passes through valve cavity 43a and into metering run return 139 for premixing with the injected additive(s). Conversely, flush cycle solenoid control valve 26

28 positioned above valve cavity 43b is kept in a normal, closed state. Thus, the product coursing through product supply header 135 is prevented from travelling through valve cavity 43b.

In response to commands from control unit 60, the additive line solenoid control valves 20 seated atop the valve cavities of rows 41 and 45 are actuated and deactuated in a manner such that the appropriate additives are injected into metering runs 124a-b. For example, one additive may be injected into metering run 124a by actuating the additive line solenoid control valve 20 seated atop the appropriate valve cavity of row 41. In this manner, the additive

flows from additive supply header 125 through the particular valve cavity of row 41 into metering run 124a. At the same time, a different additive associated with one of the remaining additive supply headers 125 may be injected into metering run 124b by the actuation of the additive line solenoid control valve 20 positioned above the appropriate valve cavity of row 45. The injected additives are directed toward and out of end cap 46 of blend manifold 40 by the presence of cartridge check valves 140a-b. Each metering run 124a-b, after leaving blend manifold 40, corresponds to the previously described metering runs 24a-b. Metering runs 24a-b take the additive to mass flowmeter 35, pass the additive through throttling control valve 29, and return the additive to blend manifold 40 through metering run return 139 where the additive is premixed with product flowing to metering run return 139 from valve cavity 43 a. The additized product slipstream then passes through outlet channel 130 on toward distribution nozzle assembly 80.

In the flushing mode, blend cycle solenoid control valve 27 is actuated so that it closes, prohibiting the flow of product through valve cavity 43a and further into metering run return 139. On the other hand, flush cycle solenoid control valve 26 is actuated so that a flow of pure product is initiated from product supply header 135 through valve cavity 43b into flush header 137 (via metering run 124b) and through the full length of both metering runs 124a

29 and 124b. The flushing flow of product is continued until all additive in metering runs 24a- is cleared through metering run return 139 and is transported to distribution nozzle assembl 80. During this process, the blend/flush solenoid control valves may be cycled to generate pressure wave that, in effect, scrubs clean blend manifold 40. Accordingly, blend manifold 40, acting as a flow control assembly and coupled wit the system control components of the invention, facilitates the continuous metering of multipl additives into a product flow in sequence through a single flowmeter. Through blend manifol 40 a first additive may be routed to mass flowmeter 35 via the additive flow path describe above such that an appropriate amount of first additive is continuously provided to the produc flow at the user defined blend ratio. After the proper amount of first additive has bee provided, the additive flow path, including mass flowmeter 35 and throttling control valve 2 down to distribution nozzle assembly 80 may be flushed with a portion of product to ensur that all of the first additive has been loaded on the transport vehicle. Subsequently, a secon additive may be provided for blending with the product in a similar fashion. Thi blending/flushing process may be continued indefinitely.

FIG. 13 and 14 provide a more detailed look at distribution nozzle assembly 80 Distribution nozzle casing 85 comprises a hollow tube preferably made to generally confor to the diameter of the product flow pipe 83 or riser. Casing 85 is provided with flanges 87a- at each of its ends and is adapted to connect to flow pipe 83. Suspended within the hollo interior of distribution nozzle casing 85 is a bullet-shaped nozzle 90. At its aft end (the en farthest upstream in relation to the product flow), nozzle bullet 90 is supplied with a conica product capture bowl 104 which functions to generate a product slipstream. The capture product is passed via a 90° elbow joint to product input feed 50 to be premixed with injecte additive or to be used to flush and clean metering runs 24a-b. Product input feed 50 has manually controllable cut-off valve 92b for use in maintenance or in emergency and i

30 threadably connected to nozzle bullet 90. Relxirning to distribution nozzle assembly 80 is additized product output feed 52. It also is provided with a manually operable cut-off valve 92a and is threadably connected to nozzle bullet 90. Another 90° elbow joint directs the additized product to the forward outlet 101 of nozzle bullet 90. Two particular effects of distribution nozzle assembly 80 bear noting. The first is that, in addition to generating a product slipstream, the conically shaped product capture bowl 104 acts as a venturi increasing the velocity and pressure characteristics of the product slipstream. This facilitates the blending and flushing features of the invention. Secondly, the shape of nozzle bullet 90, in conjunction with the passage of product around nozzle bullet 90, creates turbulence in the main product flow at an area around and immediately downstream from forward outlet 101. This turbulence further aids in the complete blending of product and additive.

Thus, the present invention uses continuous additive input to match the continuous flow of products at a truck loading facility to obtain a homogeneously blended, precisely additized product. The continuous additive control coupled with advanced flow control and measurement technology allows for greater accuracy and reliability and reduces the degree to which additives are wasted due to over-additization.

Moreover, with the present invention custody transfer metering is made available. Until now the petroleum product marketer paid for additive, not once, but twice during the purchasing process. The marketer first paid for the additive as it is delivered to the refinery terminal. He paid again when the product was loaded at the terminal. This occurred because the loading facilities measure the product and additive together, through the same meter, without differentiating between them. Though the amount of product displaced by additive in a truckload may only be one or two milliliters per gallon, this is equivalent to a liter of additive per one thousand gallon load. Thus, a substantial amount of product is lost in large

product transfers due to the displacement of product by the additive already bought by the marketer. The present invention allows the user to blend additive downstream of the product meter or subtract the additive quantity from the total quantity of delivered product should the system be configured to measure additized product flow. This is done via a certified custody transfer meter for total quality control and product transaction accounting.

Furthermore, the flexible, modular design of the present invention allows for quick, inexpensive expansion to meet growing additive needs as additive regulations and requirements change. The metering technology incorporated into the invention also allows for easier calibration. The invention communicates the amount of additive contained in each load, providing enhanced additive accounting and speedy identification of system errors. The precision process control, measurement accuracy, flexibility, reliability and ease of maintenance and calibration all combine to make the present invention an extremely cost- effective method of additizing products while meeting rigorous regulatory parameters.

While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of construction and the arrangement of components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiment set forth herein for purposes of exemplification, but is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element thereof is entitled.