Patent Description:
Vehicles that use diesel fuels emit large amounts of nitrogen oxides or, more generally, NOx. These emissions are harmful to the environment. Thus, techniques are in place to reduce these emissions. Selective catalytic reduction (SCR) is one technique that converts the NOx into diatomic nitrogen (N<NUM>) and water (H<NUM>O). SCR utilizes a reductant and a catalyst. Examples of the reductant include anhydrous ammonia, aqueous ammonia, and urea. Various standards and/or government regulations establish the proper solutions for the reductant, which in one form includes an aqueous urea solution, commonly referred to as AUS32 and identified in North America as Diesel Exhaust Fluid and abroad as AdBlue®.

Service stations throughout the world use dispensing systems that store AUS32 to provide regular access for end users that operate diesel-powered vehicles. However, these dispensing systems often encounter problems inherent with the AUS32 fluid. One problem of primary concern is crystallization of the AUS32 fluid. This problem can result in crystal build-up through the components of the dispensing system. The build-up can lead to clogs and other blockages that effectively reduce flow of the AUS32 fluid and, eventually, require maintenance to restore operability of the dispensing system.

Crystallization can occur at low temperatures and, more specifically, at and/or below the freezing point of the AUS32 fluid. The AUS32 fluid will begin to crystallize at about -<NUM>, forming a slush, and begin to solidify at about -<NUM>. Unfortunately, many service stations that wish to provide the AUS32 fuel additive are found in locations where temperatures are consistently at or below these critical temperatures for extended periods of time.

Solutions are therefore necessary to prevent crystallization of the AUS32 fluid in these cold environments. One common solution utilizes a large, heated cabinet that encloses the components of the dispensing system. The heated cabinet can maintain the entire dispensing system, or most of the dispensing system, at temperatures that are above the critical temperatures for the AUS32 discussed above. However, use of the heated cabinet, and similar heated compartments, are often considerably larger and/or are sized to heat volumes that are much larger than necessary to maintain the temperature of the AUS32. These features can lead to higher costs of operation (e.g., for the heaters and structure), complicate the refilling process for the end user, and suffer from implementation issues. For example, during a re-filling process, the end user may need to open the cabinet to extract the nozzle and/or to complete the transaction. Once the re-filling process finishes, the end user must then replace the nozzle and close the cabinet. This process relies on the end user to properly close the cabinet door to reestablish the integrity of the cabinet. Unfortunately, situations where the cabinet is not sufficiently closed and/or the cabinet door is left ajar after the re-filling process is complete will defeat the operation of the heated cabinet and can result in freezing of the AUS32 fluid.

Other solutions utilize in-situ heating techniques to elevate and maintain the temperature of the AUS32 fluid. These techniques may utilize a wire, a coil, and/or other element that inserts into the hoses that carry the fuel additive. Energizing these elements injects heat directly into the AUS32 fluid. However, although effective because the elements are in close proximity to the AUS32 fluid, the elements can reduce flow and pressure of the fuel additive in the hoses. Moreover, to afford heating throughout all components that handle the AUS32, and are thus at risk of crystallization, the dispensing system is likely to require different in-situ heating techniques with special designs for the components, e.g., hoses, nozzles, etc. This requirement can add costs and complexity to the design.

Still other solutions attempt to maintain movement of the AUS32 fluid, e.g., when the dispensing system is not in use. These systems deploy intricate fluid systems that allow the AUS32 to circulate continuously, thereby preventing stagnate conditions that can allow crystallization to occur. However, circulating systems also require complicated structure to maintain proper circulation of the AUS32 fluid as well as to avoid leaks and other problems that can lead to effluent from the dispensing system. Document <CIT> discloses a system for temperature conditioning and control of a fluid, such as liquid fuel or diesel exhaust fluid, in a fluid dispenser. Document <CIT> discloses a system for dispensing two or more different types of fuel has separate storage tanks and common pistol outlet with pipeline system with separate pipes and selection unit determining ratio of mixture.

This disclosure describes a device for dispensing fuel additive according to claim <NUM> and a fuel dispenser for a fuel dispensing system according to claim <NUM>.

Reference is now made briefly to the accompanying Appendix, in which:.

Where applicable like reference characters designate identical or corresponding components and units throughout the several views, which are not to scale unless otherwise indicated.

<FIG> depicts a schematic diagram to illustrate an exemplary embodiment of a heating system <NUM> of the present disclosure. The heating system <NUM> is part of a fluid dispensing system <NUM> (also "system <NUM>") that includes a storage tank <NUM> and a dispenser unit <NUM>. The dispensing system <NUM> also includes a hose <NUM> that places the dispenser unit <NUM> in flow connection with the storage tank <NUM>. Examples of the dispensing system <NUM> can dispense fuel additives, e.g., Diesel Exhaust Fluid (DEF), urea resin, and similar fuel additives that reduce NOx emissions in diesel-powered vehicles.

As set forth more below, the heating system <NUM> manages the temperature of the fuel additive to avoid crystallization and/or solidification. This feature allows the dispensing system <NUM> to operate in cold environments with temperatures that fall below the freezing point of the fuel additives. Embodiments of the heating system <NUM>, for example, can form a compartment structure that is sized and configured about the fuel additive-handling components of the dispenser unit <NUM>. This compartment structure can insulate these components, thus helping to maintain the temperature of the fuel additive in cold environments.

In addition to the compartment structure, the heating system <NUM> can incorporate various heating schemes that elevate the temperature of the fuel additive. These heating schemes can circulate heating fluid in close proximity to the hoses, meters, nozzles, and other components of the dispenser unit <NUM> that handle the fuel additive. In other examples, the heating system <NUM> can inject thermal energy directly into the fuel additive, e.g., via one or more immersion heaters. These configurations maintain the temperature of the fuel additive at and/or above the freezing point, thus preventing crystals from forming (or "crystallization") in the fuel additive in these components. These crystals can clog the flow path of the fuel additive, which ultimately can disrupt operation of the dispenser unit <NUM>. Moreover, solidification (or freezing) of the fuel additive solidify (or freeze) can rupture the hoses and other components of the dispenser unit <NUM>. The resulting damage can bring the dispenser unit <NUM> offline for extended periods of time due to the extensive repairs necessary to replace the damaged components.

In <FIG>, the dispenser unit <NUM> includes a nozzle assembly <NUM> and various control and operation elements (e.g., a display <NUM> and a payment device <NUM>). The dispenser unit <NUM> also includes a compartment <NUM> with a flow meter <NUM>, a fluid inlet <NUM>, and a fluid outlet <NUM>. The fluid inlet <NUM> and the fluid outlet <NUM> can comprise fluid-carrying components (e.g., hoses, pipes, couplings, and/or the like) that allow fluid flow therethrough. Examples of the fluid-carrying components are made of materials compatible with the fuel additive. In one example, the fluid inlet <NUM> couples with hose <NUM> to allow fuel additive to enter the dispenser unit <NUM>. The fluid outlet <NUM> can extend from the flow meter <NUM> to the nozzle assembly <NUM> as a single unitary member (e.g., a hose) and/or in constructions that utilize multiple pieces (e.g., multiple hoses and fluid couplings disposed therebetween). Both single and multi-piece configurations of components place the nozzle assembly <NUM> in flow connection with the flow meter <NUM>. During operation of the dispenser unit <NUM>, the fuel additive flows from the storage tank <NUM> to the flow meter <NUM> via the fluid inlet <NUM>, through the flow meter <NUM>, and from the flow meter <NUM> to the nozzle assembly <NUM> via the fluid outlet <NUM>. The fuel additive flows through the nozzle assembly <NUM> until the fuel additive dispenses, e.g., into a tank on a diesel-powered vehicle.

<FIG> illustrates a side view of the dispensing system <NUM>, e.g., taken at line <NUM>-<NUM> of <FIG>. As shown in the diagram of <FIG>, the nozzle assembly <NUM> can include one or more nozzles (e.g., a first nozzle <NUM> and a second nozzle <NUM>). The nozzle assembly <NUM> also has one or more cover system (e.g., a first cover system <NUM> and a second cover system <NUM>) that house the nozzles <NUM>, <NUM>. The cover systems <NUM>, <NUM> include a nozzle boot <NUM> and a cover <NUM> which surrounds the nozzles <NUM>, <NUM> to provide a nozzle volume <NUM>.

Construction of the cover systems <NUM>, <NUM> permits the cover <NUM> to translate from a first position, shown in <FIG>, to a second position that is different from the first position. The second position permits access to the nozzles <NUM>, <NUM>, e.g., to allow the end user to remove the nozzles <NUM>, <NUM> from the nozzle boot <NUM> to dispense fuel additive. When the nozzles <NUM>, <NUM> reside on the nozzle boot <NUM>, e.g., when the nozzles <NUM>, <NUM> are in the first position and the fuel dispenser <NUM> is not in use, the covers <NUM> cover the nozzles <NUM>, <NUM> to form the nozzle volume <NUM>.

In one embodiment, the heating system <NUM> can circulate heating fluid to the nozzle assembly <NUM>. The heating fluid disperses into the nozzle volume <NUM>, which elevates the temperature, e.g., of air, inside of the nozzle volume <NUM> proximate the nozzles <NUM>, <NUM>. This feature prevents crystallization of the fuel additive in the nozzles <NUM>, <NUM>, which often contains residual fuel additive that is left over between dispensing operations.

<FIG> depicts a schematic diagram of an exemplary embodiment of a heating system <NUM> that can prevent crystallization of fuel additives. The heating system <NUM> forms a fluid circuit in the dispenser <NUM>. The fluid circuit includes a central compartment <NUM> and one or more elongated sleeves (e.g., a first elongated sleeve <NUM>, a second elongated sleeve <NUM>, and a third elongated sleeve <NUM>). The fluid circuit <NUM> can operate as a closed-loop and/or semi-closed loop system that carries heating fluid proximate components (e.g., the flow meter <NUM>, the fuel inlet <NUM>, and the fuel outlet <NUM>) that handle the fuel additive. In one example, the heating system <NUM> includes a fluid heater <NUM>, which is shown in flow connection with the central compartment <NUM>.

Examples of the fluid heater <NUM> include devices that inject heating fluid into the fluid circuit at elevated temperatures. These devices may have a heating element and fluid moving element (e.g., a fan, a pump, etc.) that allow the fluid heater <NUM> to, respectively, heat and pressurize the heating fluid. Although shown in <FIG> as coupled with the central compartment <NUM>, this disclosure further contemplates configurations for the heating system <NUM> in which the location of the fluid heater <NUM> is remote from the heating system <NUM>. These configurations may require additional fluid-carrying components that couple the fluid heater <NUM> with heating system <NUM> and, in one example, a hose that places the fluid heater <NUM> in flow connection with the central compartment <NUM>.

The central compartment <NUM> can form a sealed (and/or partially sealed) enclosure about the flow meter <NUM>. This enclosure has properties that prevent thermal conduction of heat from the inside of the enclosure to the outside of the enclosure. For example, the enclosure can comprise insulation and other materials with relatively low thermal conductivity. These materials may form one or more walls of the enclosure and/or may find use as a liner that is disposed on an outer shell that forms the general structure of the central compartment <NUM>.

The elongated sleeves <NUM>, <NUM>, <NUM> couple with the central compartment <NUM> to allow heating fluid to flow along the hoses and pipes of the fuel inlet <NUM> and the fuel outlet <NUM>. This configuration disperses the heating fluid proximate the surface of the hoses and pipes to maintain the temperature along these components above the freezing point of the fuel additive. Devices for use as the elongated sleeves <NUM>, <NUM>, <NUM> fit about these hoses and pipes to form a coaxial fluid pathway to allow the heating fluid to pass between the outer surface of the hoses and pipes and the inner surface of the elongated sleeves <NUM>, <NUM>, <NUM>.

<FIG> depicts a cross-section view of the elongated sleeve <NUM> taken at the line <NUM>-<NUM> of <FIG> to illustrate an example of the coaxial fluid pathway. In <FIG>, the elongated sleeve <NUM> has an outer sleeve surface <NUM> and an inner sleeve surface <NUM> that bounds a first flow area <NUM>. The fluid inlet <NUM> includes a hose with an outer hose surface <NUM> and an inner hose surface <NUM> that bounds a second flow area <NUM>. As shown in <FIG>, the size of the hose is smaller is relative to the size of the elongated sleeve <NUM>, thus forming a gap <NUM> between the inner sleeve surface <NUM> and the outer hose surface <NUM>. When implemented as part of the heating system <NUM> (<FIG>), heating fluid can flow in the gap <NUM> and along the outer hose surface <NUM>. This feature allows thermal energy to transfer from the heating fluid to the outer hose surface <NUM>. The transfer raises and/or maintains the temperature of the hose at and/or above the freezing point of the fuel additive.

<FIG> illustrates an exemplary flow pattern for heating fluid that travels in the coaxial pathway of the heating system <NUM>. This flow pattern shows the distribution of heating fluid from, e.g., the fluid heater <NUM>, about the central compartment <NUM> and into the elongated sleeves <NUM>, <NUM>, <NUM>. As shown in <FIG>, the coaxial pathway can extend to the nozzles <NUM>, <NUM> to allow heating fluid to flow along the entirety of the hoses that supply fuel additive to the nozzles <NUM>, <NUM>. Although not shown as part of the flow pattern, this disclosure contemplates configurations of the heating system <NUM> in which the flow pattern allows heating fluid to circulate, and/or re-circulate, about the fluid circuit of the proposed designs. To this end, the heating system <NUM> may utilize a pressure-release mechanism and/or slow leak configuration in one or more components of the heating system <NUM> to exhaust heating fluid from the fluid circuit. This feature prevents pressurization of the fluid circuit that would prevent movement of heating fluid, e.g., as shown in the flow pattern of <FIG>.

<FIG> depicts a schematic diagram of an exemplary embodiment of a heating system <NUM> that illustrates one configuration to distribute heating fluid in the dispensing unit <NUM> and, in particular, into the nozzle volume <NUM> of the cover systems <NUM>, <NUM>. This configuration maintains the temperature of fuel additive that may reside in the nozzles <NUM>, <NUM>. In the example of <FIG>, the heating system <NUM> includes one or more nozzle fluid paths (e.g., a first nozzle fluid path <NUM> and a second nozzle fluid path <NUM>). The nozzle fluid paths <NUM>, <NUM> couple with the fluid circuit, e.g., at the central compartment <NUM>, and to nozzle volume (e.g., nozzle volume <NUM> of <FIG>). This configuration exposes the nozzles to heating fluid that flows from the enclosure of the central compartment <NUM>. In one example, one or more of the nozzle fluid paths <NUM>, <NUM> couple with other parts of the fluid circuit, e.g., the elongated sleeves to provide the supply of heating fluid into the nozzle volume (e.g., nozzle volume <NUM> of <FIG>).

Turning next to <FIG>, an exemplary embodiment of a heating system <NUM> can include one or more separate fluid circuits to distribute heating fluid about the components that handle the fuel additive. As <FIG> illustrates, the heating system <NUM> can include a first fluid circuit <NUM> and a second fluid circuit <NUM>. The first fluid circuit <NUM>, as set forth above, circulates heating fluid proximate the flow meter <NUM> and along the fluid inlet <NUM> and the fluid outlet <NUM>. The second fluid circuit <NUM> can include the nozzle fluid paths <NUM>, <NUM> and, in one example, a nozzle heater <NUM>. In one implementation, the nozzle heater <NUM> includes one or more devices that inject heating fluid into the nozzle fluid paths <NUM>, <NUM> to circulate into the nozzle volume <NUM> of the cover systems <NUM>, <NUM> to maintain the temperature of fuel additive in the nozzles <NUM>, <NUM>.

<FIG> and <FIG> illustrate configurations of heating systems that inject thermal energy directly into the fuel additive. The diagram of <FIG>, for example, depicts an exemplary embodiment of a heating system <NUM> that includes a heating element <NUM> in the flow path of the fuel additive from the fuel inlet <NUM> to the flow meter <NUM>. The heating system <NUM> of <FIG> includes another exemplary heating element in the form of an elongated wire and/or filament <NUM> that inserts into one or more of the fuel inlet <NUM> and the fuel outlets <NUM>. Examples of the heating element <NUM> and the wires <NUM> can include devices that generate thermal energy to elevate the temperature of the fuel additive, e.g., as the fuel additive flows through the fuel dispenser <NUM>. These devices may require an input, e.g., electrical signals having specified current and/or voltage to stimulate the thermal energy. In one example, the fuel dispenser <NUM>, <NUM> is configured to circulate the fuel additive among the components (e.g., the flow meter <NUM>, <NUM> the fuel inlet <NUM>, <NUM> the fuel outlet <NUM>, <NUM> and/or the nozzles <NUM>, <NUM> and nozzles <NUM>, <NUM>). Circulation facilitates contact of the fuel additive with the heating element <NUM> and the wires <NUM> to maintain the elevated temperature of the fuel additive when the fuel dispenser <NUM>, <NUM> is not in use to dispense the fuel additive.

Collectively, the central compartment (e.g., central compartment <NUM>, <NUM>) and the elongated sleeves (e.g., elongated sleeves <NUM>, <NUM>, <NUM> and elongated sleeves <NUM>, <NUM>, <NUM>) can form a unitary and/or partially unitary chamber and/or compartment. This chamber insulates the components that carry the fuel additive. This configuration limits dissipation of heat energy from the fuel additive, thereby promoting effective heating and temperature maintenance of the fuel additive by the heating element <NUM> and the wires <NUM>.

Furthermore, this disclosure contemplates combinations of one or more heating concepts to maintain and/or elevate the temperature of fuel additive. For example, the insulating chambers (as shown in <FIG> and <FIG>) can also operate as fluid circuits to allow heating fluid to traverse among the components of the dispenser. Such combinations of concepts may provide favorable temperature maintenance for particularly harsh, cold climates.

<FIG> depicts a schematic diagram that presents, at a high level, a wiring schematic for an embodiment of a heating system <NUM> that can maintain temperature inside of fuel dispensers above the freezing point of fuel additives. The heating system <NUM> includes a control device <NUM> with a processor <NUM>, a memory <NUM>, and control circuitry <NUM>. Busses <NUM> couple the components of the control device <NUM> together to permit the exchange of signals, data, and information from one component to another in the heating system <NUM>. In one example, the control circuitry <NUM> includes sensing circuitry <NUM> that couples with one or more sensing devices (e.g., a first sensing device <NUM>). The control circuitry <NUM> can also include heater drive circuitry <NUM> that couples with one or more heaters (e.g., the fluid heater <NUM> and the nozzle heater <NUM>). As also shown in <FIG>, memory <NUM> can include one or more software programs <NUM> in the form of software and/or firmware, each of which can comprise one or more executable instructions configured to be executed by the processor <NUM>.

In one implementation, this configuration of components can properly elevate the temperature within the heating system <NUM>. For example, the control device <NUM> can receive signals from the sensing device <NUM> that contain and/or embed information about the temperature in and around the fluid circuit of the heating system <NUM> and/or of the fuel additive. The control device <NUM> can process these signals to generate an output that, in one example, includes instructions to operate one or more of the heaters (e.g., the fluid heater <NUM>, the nozzle heater <NUM>, the heating element <NUM>, and/or wires <NUM>). For example, these instructions may cause the fluid heater <NUM> to turn on to circulate heating fluid when the temperature fails to satisfy a threshold criteria (e.g., is less than a threshold minimum temperature). On the other hand, the instructions may also cause the fluid heater <NUM> to turn off to stop heating fluid from circulating, e.g., when the temperature satisfies the threshold criteria (e.g., is greater than the threshold minimum temperature). In this way, the control device <NUM> can manage both temperature of the components that the heating system <NUM> heats as well as power consumption of the heater device <NUM>.

The control device <NUM> (and the other components of heating system <NUM>) and its constructive components can communicate amongst themselves and/or with other circuits (and/or devices), which execute high-level logic functions, algorithms, as well as executable instructions (e.g., firmware instructions, software instructions, software programs, etc.). Exemplary circuits of this type include discrete elements such as resistors, transistors, diodes, switches, and capacitors. Examples of the processor <NUM> include microprocessors and other logic devices such as field programmable gate arrays ("FPGAs") and application specific integrated circuits ("ASICs"). Although all of the discrete elements, circuits, and devices function individually in a manner that is generally understood by those artisans that have ordinary skill in the electrical arts, it is their combination and integration into functional electrical groups and circuits that generally provide for the concepts that are disclosed and described herein.

The structure of the components in the control device <NUM> can permit certain determinations as to selected configurations and desired operating characteristics for the heating system <NUM>. An end user can convey this information via a graphical user interface or the control device <NUM> can retrieve this information, e.g., from a central database and/or computer. In lieu of software and firmware, the control device <NUM> may instead utilize electrical circuits that can physically manifest the necessary logical operations and/or can replicate in physical form an algorithm, a comparative analysis, and/or a decisional logic tree, each of which operates to assign outputs and/or a value to outputs that correctly reflects one or more of the nature, content, and origin of the changes that occur and that are reflected by the signals the control device <NUM> receives, e.g., at the control circuitry <NUM>.

In one embodiment, the processor <NUM> is a central processing unit (CPU) such as an ASIC and/or an FPGA that is configured to instruct and/or control operation of one or more devices. This processor can also include state machine circuitry or other suitable components capable of controlling operation of the components as described herein. The memory <NUM> includes volatile and non-volatile memory and can store executable instructions in the form of and/or including software (or firmware) instructions and configuration settings. Each of the control circuitry <NUM> can embody stand-alone devices such as solid-state devices. Examples of these devices can mount to substrates such as printed-circuit boards and semiconductors, which can accommodate various components including the processor <NUM>, the memory <NUM>, and other related circuitry to facilitate operation of the control device <NUM>.

However, although <FIG> shows the processor <NUM>, the memory <NUM>, and the components of the control circuitry <NUM> as discrete circuitry and combinations of discrete components, this need not be the case. For example, one or more of these components can comprise a single integrated circuit (IC) or other component. As another example, the processor <NUM> can include internal program memory such as RAM and/or ROM. Similarly, any one or more of functions of these components can be distributed across additional components (e.g., multiple processors or other components).

Claim 1:
A device (<NUM>) for dispensing a fuel additive, said device (<NUM>) comprising:
a flow meter (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>);
a hose (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>) configured to carry fuel additive from the flow meter (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>);
a compartment structure with a central compartment (<NUM>; <NUM>; <NUM>) enclosing the flow meter (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>);
an elongated sleeve (<NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>) coupled with the central compartment (<NUM>; <NUM>; <NUM>) and circumscribing the hose (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>);
a first fluid heater (<NUM>; <NUM>) coupled in flow connection with the compartment structure to disperse a heating fluid therein;
a nozzle (<NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>) coupled to the hose (<NUM>; <NUM>; <NUM>; <NUM>; <NUM>);
characterised in that the device further comprises:
a second fluid heater (<NUM>) coupled in flow connection with a nozzle volume (<NUM>; <NUM>; <NUM>) that surrounds the nozzle (<NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>; <NUM>, <NUM>).