Dilution device for dispensing fluid

A dilution device may include a first component and a second component. The first component may define a groove including an inlet portion and an outlet portion. The second component may define an inlet in fluid communication with the inlet portion of the first component and an outlet in fluid communication with the outlet portion of the first component. Relative rotation between the first component and the second component may cause relative movement between the outlet and the outlet portion that changes the effective length of the groove fluidly coupling the inlet and the outlet of the second component. The cross-sectional area of the groove may vary along a length of the groove to provide different flow characteristics depending on the effective length of the groove.

TECHNICAL FIELD

The present disclosure relates to fluid metering, such as fluid metering at low dilution ratios and draw rates. More particularly, the present disclosure relates to a dilution device for dispensing fluid, such as a chemical for use in the car wash industry.

BACKGROUND

Chemicals and especially chemicals used in the car wash industry have become increasingly concentrated in order to reduce material handling concerns and shipping costs of those chemicals. Most concentrated chemicals are diluted with water prior to or during application. For more concentrated chemicals, the dilution ratios have increased (i.e., less chemical, more water).

Traditionally chemicals have been metered by use of a pump or a small hole that restricts the flow of chemical. Typically, the diameter of the hole is changed to provide a desired flow of chemical. Alternatively, the length (depth) of the hole has been changed to create more drag on a fluid flowing through the hole, thereby restricting the flow of chemical through the hole (this is commonly referred to as a capillary or metering tube). Metering tubes typically use a larger diameter hole and can be less susceptible to clogging from small particulate as it merely passes through the larger diameter hole, but metering tubes are often very long and difficult to use as they must be cut to length.

As dilution ratios increase based on the use of more concentrated chemicals, it becomes increasingly difficult to provide accurate and consistent flow of chemical to a dilution device. For example, many dilution devices are unable to achieve sufficiently low draw rates to provide a desired mixture of chemical and water, and thus the mixture includes extraneous chemical. The more concentrated chemicals are expensive, and thus it is desirable to use as little chemical as possible. To wash a car, typically 30 to 60 milliliters (ml) of standard concentrate chemical and 0.5 to 2.5 gallons of water are used in a single 30-second application, whereas only 3 to 10 ml of more concentrated chemical may be used in a similar time. The use rate recommendations by the chemical manufacturers are trending lower, but the technology for metering the chemical has not been able to keep up with the ability to further concentrate the chemical.

Traditional dilution devices lack sufficient accuracy for metering the more concentrated chemicals. Many devices include incremental adjustments for dilution ratio. However, as the recommended use rates of chemical are lowered, the adjustment increments are more inaccurate on a percentage basis. For example, for a dilution device that is adjustable in 6 ml increments, this adjustment increment (6 ml) is 20% of a 30 ml chemical draw, but it is 100% of a 6 ml chemical draw. The inability to accurately adjust for a proper amount of chemical results in chemical waste.

Additionally, as the dilution ratios increase, it is more difficult to fully and evenly mix chemical with water. In other words, it is harder to completely and evenly mix 3 ml of chemical with one gallon of water than it is to mix 30 ml of chemical with one gallon of water. Thus, the variation in dilution ratio throughout the diluted mixture increases as the dilution ratios increase. These variations in dilution ratio create pockets of rich and lean chemical dilutions that are wasteful because the metering device has to be set at a lower dilution ratio (more chemical, less water) that ensures the areas in the mixture with the lowest chemical content are sufficient to clean the car.

Moreover, to decrease the chemical draws, dilution devices typically use smaller and smaller passageways and orifices to meter the chemical. Particulate in the chemical is more likely to clog these passageways and orifices in the dilution device, causing operational concerns as a clogged dilution device does not produce the correct concentration of chemical. Dilution devices for low flows typically use a small size metering diameter in the 0.005 inch range, which is easily clogged by very fine particulate.

SUMMARY

In some embodiments, a dilution device is provided. The dilution device may include a metering component defining a metering groove with flow characteristics that vary along a length of the groove. For example, the depth and/or the width of the groove may vary along the length of the groove to provide different flow characteristics along the length of the groove. Additionally or alternatively, the metering groove may change directions along its length to provide different flow characteristics along the length of the groove. The dilution device may include another component defining an inlet and an outlet, and the groove may at least partially define a flow path between the inlet and the outlet. The outlet may be alignable with different portions of the groove to change the effective length of the groove that fluidly couples the inlet and the outlet.

In some examples, a dilution device according to embodiments of the present disclosure may include a first component defining a groove including an inlet portion and an outlet portion, and a second component defining an inlet in fluid communication with the inlet portion of the first component and an outlet in fluid communication with the outlet portion of the first component. Relative rotation between the first component and the second component may cause relative movement between the outlet and the outlet portion that changes the effective length of the groove fluidly coupling the inlet and the outlet of the second component. The cross-sectional area of the groove may vary along a length of the groove to provide different flow restriction depending on the effective length of the groove.

In some examples, the depth and the width of the groove may vary along the length of the groove. In some embodiments, the groove can travel along a tortuous path with multiple direction changes. In some examples, the first component comprises a metering disc. In some embodiments, the relative rotation between the first component and the second component is automatically controlled without user intervention. In some examples, the second component comprises a first housing coupled with a second housing, the first housing defining an aperture and the second housing defining the inlet and the outlet.

In some embodiments, a dilution device also includes an adjustment feature configured to cause the relative rotation between the first component and the second component responsive to user manipulation. In some examples, the adjustment feature comprises a slot. In some examples, the dilution device also includes a biasing element configured to bias the first component against an internal surface of the second component. In some embodiments, the biasing element comprises a wave spring. In some examples, the outlet portion comprises a plurality of outlet portion segments radially distributed around a surface of the first component. In some embodiments, the plurality of outlet portion segments are evenly spaced with respect to each other.

According to some embodiments of the present disclosure, a dilution system may include a dilution device defining a flow channel in fluid communication with a concentrated chemical, and an eductor in fluid communication with the flow channel and a motive fluid. The motive fluid may flow through the eductor and create a suction force that draws the concentrated chemical into the flow path of the motive fluid to mix the concentrated chemical with the motive fluid.

In some examples, the dilution system further comprises at least two sealing elements that create a fluid-tight interface between the dilution device and the eductor. In some embodiments, the dilution system also includes a control system configured to adjust the amount of concentrated chemical drawn into the flow path of the motive fluid without user intervention. In some examples, the dilution device can be rotatable with respect to the eductor. In some embodiments, the flow channel can be configured to adjust a flow rate of the concentrated chemical through the dilution device upon rotation thereof.

According to some embodiments of the present disclosure, a method of diluting a chemical concentrate with a fluid may involve biasing a metering disc into engagement with an eductor body to form a flow channel between the metering disc and the eductor body. The method may also involve sealing the flow channel by deforming one of the metering disc or the eductor body with ridges on the other of the metering disc or the eductor that extend along edges of the flow channel. The method may further involve rotating the metering disc relative to an eductor body to change an effective length of a metering groove fluidly coupling a concentrated chemical and a motive fluid to vary dilution of the concentrated chemical. In some examples, rotating the metering disc relative to the eductor body comprises autonomously rotating the metering disc based one or more monitored conditions

DETAILED DESCRIPTION

Described herein is a device that meters a concentrated substance such as one or more chemicals, gases, soaps, detergents, rinsing agents, foaming agents, and/or liquid waxes. For convenience without an intent to limit, the concentrated substance will be referred to herein as a chemical. The device may use a combination of length and cross-sectional area variations of a flow channel to meter the flow of chemical to a chemical mixing device, such as a Venturi. By combining the effect of cross-sectional area and length variations of a flow channel, the device may be compact and may include a flow channel with relatively short effective lengths and a relatively larger cross-sectional area that more easily passes particulate.

The length of the flow channel can be shortened or elongated by relative movement between two or more components of the device. The chemical flow rate initially may change quickly as a flow channel increases in length, and after the initial change the flow rate of chemical may change less quickly as the length of the flow channel increases further. In certain implementations, the device includes a metering component (such as a disc, sleeve, slide, or other component) that is incrementally adjustable to provide incremental adjustment of the effective length of the flow channel. In certain implementations, the device includes a metering component that is continuously adjustable to provide continuous adjustment of the effective length of the flow channel. The metering component may include a flow channel with a cross-sectional area that varies along the length of the flow channel to provide additional adjustment of the chemical flow rate. Thus, relative rotation between two components of the device can vary at least two parameters of the flow channel: its effective length and its effective cross-sectional area. The cross-sectional shape of the flow channel may be circular or non-circular. Different metering components with different configurations may be used to provide different flow rates and metering ranges. The metering component may be formed from various types of materials, such as stainless steel, hastelloy-C, or other chemical compatible materials.

The device may be configured to seal the flow channel to an adjacent surface so that chemical does not leak out of the flow channel. For example, the device may include flat, relatively-hard surfaces that collectively define a flow channel therebetween. As another example, the device may include a harder surface and a softer surface that is deformable by the harder surface. Small ridges may be formed in the harder surface, and the small ridges may engage the softer surface along opposing edges of a metering groove to deform the softer surface and form a seal between the harder surface and the softer surface. The small ridges may deform the softer surface by high contact pressure and may at least partially create the groove. The harder surface and/or the softer surface may be injection molded out of inexpensive and highly chemical compatible plastics, such as high-density polyethylene (HDPE). In certain implementations, the softer surface may be formed from an elastomer.

An eductor may be attached to the device, allowing concentrated chemicals, gases, or other materials to be mixed with a motive fluid such as water. Accurately-diluted fluid mixtures may be emitted through the eductor outlet. By creating a fluid-tight seal between the device and the eductor, the combined device and eductor may be more resistant to leaks than pre-existing apparatus. Features from any of the disclosed embodiments may be used in combination with one another, without limitation. In addition, other features and advantages of the present disclosure will become apparent to those of ordinary skill in the art through consideration of the following detailed description and the accompanying drawings.

FIG. 1is a schematic illustration of a dilution device100for dispensing fluid, such as a metering device for dispensing car wash solution. The dilution device100includes an inlet102and an outlet104. The inlet102may be in fluid communication with a chemical, which may be stored in a chemical container at atmospheric pressure. The outlet104may be in fluid communication with the inlet102via a flow channel, which is described in more detail below. The outlet104also may be in fluid communication with a chemical mixing device, such as an eductor. For example, the outlet104may be fluidly coupled with a chemical inlet of an eductor. In certain implementations, the chemical inlet of the eductor typically draws 25 to 28 inches of mercury (inHg) of vacuum with an inlet water pressure of 200 pound force per square inch (psi). The difference between the vacuum in the eductor and the atmospheric pressure at the inlet102creates a pressure differential that draws chemical thru the dilution device100.

As illustrated inFIG. 1, the dilution device100may include a first housing component106and a second housing component108. The first housing component106may function as a cover for the second housing component108. In certain implementations, the first housing component106may be formed as a plate. The inlet102and the outlet104may be formed as thru-holes that extend through the second housing component108. As shown inFIG. 1, the inlet102and the outlet104may open through an exterior surface110, such as a bottom surface, of the second housing component108. The outer surface110may be planar (i.e., flat), and may be formed of machined polyethylene. The inlet102may be located at a center of the outer surface110of the second housing component108, and the outlet104may be located radially outward from the inlet102. The first housing component106and the second housing component108may be coupled together with one or more fasteners, such as screws. The one or more fasteners may be received in one or more holes112arranged around a peripheral portion of the first and second housing components106,108radially outward of the inlet102and the outlet104.

FIG. 2is a schematic illustration of an exploded view of the dilution device100. As illustrated inFIG. 2, the dilution device100includes a metering component, such as metering disc116. The metering disc116may be received in a cavity118formed at least partially in the second housing component108. The inlet102and the outlet104may open through an interior surface120of the second housing component108into the cavity118. The interior surface120may be planar (i.e., flat). The metering disc116may sealingly engage the second housing component108to maintain fluid flow between the inlet102and the outlet104with little to no leaking. For example, a sealing element may be retained in a groove122formed in a circumferential surface124of the metering disc116, and the sealing element may engage a corresponding circumferential surface126of the second housing component108to form a fluid-tight seal between the metering disc116and the second housing component108. The circumferential surface126may extend orthogonally to the interior surface120. The interior surface120may form a fluid-tight seal with a corresponding surface of the metering disc116, as described in more detail below.

The metering disc116may be rotatable relative to the first housing component106, the second housing component108, or both. As illustrated inFIG. 2, the metering disc116may include a user engagement feature128to facilitate rotating the metering disc116relative to the second housing component108. The user engagement feature128, such as the illustrated adjustment slot, may be accessible through an aperture130formed through the first housing component106. The metering disc116may provide continuous or discrete adjustment relative to the second housing component108. In certain implementations, the metering disc116may include an increment feature132, such as a series of detent grooves, that work in conjunction with a corresponding increment feature134, such as a detent ball, of the first housing component106to provide consistent and reliable angularly increments, such as 10 degree increments, of the metering disc116relative to the second housing component108. The increment features132,134may be omitted for implementations where the adjustment is analog and not discrete.

FIGS. 3A and 3Bare schematic illustrations of a cross-sectional view of a flow channel140of the dilution device100. The flow channel140may fluidly couple the inlet102and the outlet104. The flow channel140may be formed between confronting surfaces of the metering disc116and the second housing component108. For example, the flow channel140may be formed collectively by the interior surface120of the second housing component108and a corresponding surface142of the metering disc116. In certain implementations, the metering disc116may define a groove144that determines a flow path for chemical to flow between the inlet102and the outlet104. To maintain chemical in the flow channel140, the corresponding surfaces120,142of the second housing component108and the metering disc116, respectively, may form a fluid-tight seal along the edges of the groove144. For example, the surfaces120,142may be formed as flat surfaces with tight tolerances to form a fluid-tight interface between the surfaces120,142. For example, the surface120, the surface142, or both may be flat within 0.0002 of an inch, resulting in a typical leak rate of less than 1 ml of water per minute. Less flatness typically results in more leakage internal to the disc116, and thus less capability to meter chemical to sufficiently low values for ultra-concentrated chemical. Additionally or alternatively, a seal feature may be formed along the edges of the groove144. For example, as illustrated inFIG. 3B, a ridge146may extend along each edge of the groove144. The ridges146may protrude from the surface142of the metering disc116and may sealingly engage the interior surface120of the second housing component108to substantially prevent chemical from escaping the flow channel140. The surfaces120,142may be formed from materials that facilitate a fluid-tight interface therebetween. For example, in certain implementations, the surface142of the metering disc116is formed of metal, such as stainless steel, and the interior surface120of the second housing component108is formed of polyethylene to promote sealing between the surfaces120,142. The groove144may be formed in the surface142in various manners, such as end milling.

FIG. 4is a schematic illustration of another exploded view of the dilution device100. The metering disc116may be biased toward the second housing component108. For example, the surface142of the metering disc116may be biased into engagement with the interior surface120(seeFIG. 2) of the second housing component108to facilitate a fluid-tight seal along the edges of the groove144. As illustrated inFIG. 4, a biasing element, such as wave spring148, may bias, such as press, the metering disc116against the surface120(seeFIG. 2) of the second housing component108to promote sealing between the surfaces120,142. The wave spring148may be coupled to the first housing component106and may at least partially surround the aperture130such that the wave spring148does not interfere with adjustment of the metering disc116relative to the second housing component108.

With continued reference toFIG. 4, the inlet102and the outlet104of the second housing component108are in fluid communication with the metering groove144on the metering disc116. For example, the groove144may include an inlet portion150that is in fluid communication with the inlet102and may include an outlet portion152that is in fluid communication with the outlet104regardless of the angular position of the metering disc116relative to the second housing component108. The groove144may be formed in the surface142of the metering disc116and may extend from a center of the surface142to a peripheral area of the surface142. The inlet portion150of the groove144may be located at the center of the surface142, and the outlet portion152of the groove144may extend along a peripheral area of the surface142. Rotation of the metering disc116relative to the second housing component108may change the effective length of the groove144through which chemical flows from the inlet102to the outlet104. For example, depending on the angular position of the metering disc116relative to the second housing component108, the outlet104may be aligned with different points of the outlet portion152of the groove144, while the inlet102may remain aligned with the inlet portion150of the groove144, thus changing the length of the flow path between the inlet102and the outlet104through the groove144.

FIG. 5is a schematic illustration of the metering disc116with an analog adjustment set-up. The metering groove144is configured to provide continuous adjustment of the amount of chemical for mixing with another fluid, such as water. As illustrated inFIG. 5, the groove144may extend radially outward from its inlet portion150to its outlet portion152. The outlet portion152of the groove144may extend along an arcuate path (e.g., circular path) around the peripheral area of the surface142of the metering disc116, and the shortest distance between the inlet portion150and the outlet portion152may define a radius of curvature of the outlet portion152. The distance between the inlet portion150and the outlet portion152of the groove144may match the distance between the inlet102and the outlet104of the second housing component108(see, e.g.,FIG. 4) such that the inlet102is aligned with the inlet portion150of the groove144and the outlet104is aligned with the outlet portion152of the groove144during rotation of the metering disc116relative to the second housing component108. The groove144may originate at the inlet portion152and may terminate at an end154of the outlet portion152to define a maximum effective length of the groove144.

With continued reference toFIG. 5, the groove144may include one or more features that affect the flow rate of chemical through the groove144from the inlet102to the outlet104of the second housing component108, in addition to being able to vary the effective length of the groove144. For example, the cross-sectional area of the groove144is varied along its length. To vary the cross-sectional area, the width and depth of the groove144are varied along the length of the groove144. The width and depth of the groove144may be varied such that rotation of the metering disc116in one direction relative to the second housing component108causes the chemical flow rate to continually decrease, and rotation of the metering disc116in an opposite direction relative to the second housing component108causes the chemical flow rate to continually increase. In certain implementations, the depth and the width of the groove144are decreased along the length of the groove144from the inlet portion150to the end154of the groove144. In these implementations, moving the outlet104of the second housing component108closer to the end154along the length of the outlet portion152of the groove144causes the chemical flow rate to decrease, and moving the outlet104away from the end154along the length of the outlet portion152of the groove144causes the chemical flow rate to increase. In one implementation, the groove144may be about 0.020 inches wide at its end154.

Referring still toFIG. 5, the groove144may include a tortuous path portion156that affects the flow rate of chemical from the inlet102to the outlet104of the second housing component108. The tortuous path portion156may be located entirely between the inlet portion150and the outlet portion152and may fluidly couple the inlet portion150and the outlet portion152. For example, as illustrated inFIG. 5, the tortuous path portion156may be located along a radial direction extending between the inlet portion150located at a center of the surface142and the outlet portion152located along a peripheral area of the surface142. The tortuous path portion156may restrict the flow of chemical from the inlet portion150to the outlet portion152of the groove144, thereby decreasing chemical flow. The tortuous path portion156may include twists, turns, and/or other variations in the path of the metering groove144to restrict chemical flow from the inlet portion150to the outlet portion152. For example, the tortuous path portion156illustrated inFIG. 5includes eight direction changes (for example, ninety degree bends) in the groove144between the inlet portion160and the outlet portion152that increase flow losses. The number and configuration of direction changes may be varied to achieve desired flow characteristics for a particular implementation.

FIG. 6is a schematic illustration of a metering disc216for the dilution device100that provides discrete adjustments and ultra-low chemical draws. The metering disc216is similar to the metering disc116, except as described hereinafter. In the following description, features similar to those previously described and illustrated inFIGS. 2-5are designated with the same reference numbers increased by 100 and redundant description is omitted.

As illustrated inFIG. 6, the metering disc216includes a metering groove244formed in a flat surface242. The metering groove244originates at an inlet portion250and terminates at an end254. Additional length has been added to the groove244as compared to the groove144illustrated inFIG. 5, and the additional length provides the capability to further restrict chemical flow from the inlet102to the outlet104(seeFIG. 1). Similar to the groove144, the depth and width of the metering groove244are decreased along the length of the groove244to provide the capability of low chemical draw rates. Also similar to the groove144, the metering groove244includes a tortuous path portion256located between the inlet portion250and the outlet portion252to further restrict chemical flow from the inlet102to the outlet104(seeFIG. 1).

Referring still toFIG. 6, to provide the capability of decreased chemical draw rates relative to the metering groove144, the metering groove244includes flow path disruptions (e.g., direction changes such as twists and turns) in the outlet portion252of the groove244, and these additional disruptions further restrict the flow of chemical from the inlet portion250toward the end254of the groove244. In the implementation illustrated inFIG. 6, the outlet portion252of the groove244is divided into multiple segments (hereinafter “outlet portion segments252”) arranged along the same radius of curvature originating at the inlet portion250, and the outlet portion segments252are spaced apart from one another to provide discrete rotational positions of the metering disc216relative to the second housing component108at which the outlet104(seeFIG. 1) is aligned with the outlet portion segments252to permit chemical flow from the inlet102to the outlet104(seeFIG. 1). In other words, the outlet portion segments252are intermittently aligned with the outlet104(seeFIG. 1) during rotation of the metering disc216relative to the second housing component108to selectively allow chemical flow from the inlet102to the outlet104(seeFIG. 1).

As illustrated inFIG. 6, tortuous path portions258may fluidly couple immediately adjacent outlet portion segments252to provide a continuous flow path from the inlet portion250to the end254of the metering groove244. The tortuous path portions258each may extend radially inward from ends of immediately adjacent outlet portion segments252toward the inlet portion250. The tortuous path portions258increase the overall length of the metering groove244, thereby increasing the flow restriction capability of the groove244. The tortuous path portions258may include twists, turns, and/or other variations in the path of the metering groove244to further restrict chemical flow. For example, the tortuous path portions258illustrated inFIG. 6each add twenty direction changes (for example, ninety degree bends) in the groove244between immediately adjacent outlet portion segments252to increase flow losses, thereby further restricting chemical flow. Moving the outlet104of the second housing component108(seeFIG. 1) closer to the end154of the groove244(e.g., clockwise inFIG. 6) causes the chemical flow rate to decrease because, for example, the tortuous path portions258increase the effective length of the groove244coupling the inlet102and the outlet104and increase flow losses due to flow path direction changes. Alternatively, moving the outlet104of the second housing component108(seeFIG. 1) away from the end154of the groove244(e.g., counterclockwise inFIG. 6) causes the chemical flow rate to increase because, for example, the effective length and flow losses of the groove244are decreased due to the inclusion of fewer tortuous path portions258in the flow path between the inlet102and outlet104(seeFIG. 1). The number and configuration of direction changes of the tortuous path portions258may be varied to achieve desired flow characteristics for a particular implementation. The geometry of the metering groove244illustrated inFIG. 6achieved ultra-low draw rates in testing, such as producing draw rates as low as 0.2 ml of water per minute.

FIG. 7is a schematic illustration of a metering disc316for the dilution device100ofFIG. 1and including a metering groove344having variable length and area to affect draw rates. The metering disc316is similar to the metering disc216, except as described hereinafter. In the following description, features similar to those previously described and illustrated inFIG. 6are designated with the same reference numbers increased by 100 and redundant description is omitted.

As illustrated inFIG. 7, the metering disc316includes a metering groove344formed in a flat surface342. The metering groove344originates at an inlet portion350and terminates at an end354. Similar to the outlet portion252of the metering groove244illustrated inFIG. 6, the outlet portion352of the metering groove344is divided into multiple segments (hereinafter “outlet portion segments352”) arranged along the same radius of curvature originating at the inlet portion250, and the outlet portion segments352are spaced apart from one another to provide discrete rotational positions of the metering disc316relative to the second housing component108at which the outlet104(seeFIG. 1) is aligned with the outlet portion segments352to permit chemical flow from the inlet102to the outlet104(seeFIG. 1). In other words, the outlet portion segments352are intermittently aligned with the outlet104(seeFIG. 1) during rotation of the metering disc316relative to the second housing component108to selectively allow chemical flow from the inlet102to the outlet104(seeFIG. 1).

Similar to the metering groove244, the metering groove344includes flow path direction changes such as twists and turns in the outlet portion352of the groove344. As illustrated inFIG. 7, tortuous path portions358may fluidly couple immediately adjacent outlet portion segments352to increase the flow restriction capability of the groove344such as by increasing the overall length of the metering groove344and by increasing flow losses via changing the flow direction of fluid through the groove344. The tortuous path portions358illustrated inFIG. 7each add three direction changes (for example, acute bends) in the groove344between immediately adjacent outlet portion segments352to increase flow losses, thereby restricting chemical flow. The tortuous path portions358add fewer direction changes than the tortuous path portions258illustrated inFIG. 6to provide less flow restriction, but the angle of the direction changes in tortuous path portions358is more severe than the angle of direction changes in tortuous path portions258to provide more flow restriction. The number and configuration of direction changes of the tortuous path portions358may be varied to achieve desired flow characteristics for a particular implementation.

In contrast to the metering groove244, the tortuous path portions358may vary in length relative to one another. For example, as illustrated inFIG. 7, the tortuous path portions358may gradually increase in length in a radial direction (e.g., direction defined between the inlet portion350and respective outlet portion segments352) as the metering groove344approaches its end354, thereby increasing flow restriction as the outlet104(seeFIG. 1) is moved toward the end354of the groove344. Additionally or alternatively, as illustrated inFIG. 7, the groove344may include select tortuous path portions360of greater length than adjacent tortuous path portions358to provide a desired flow characteristic at a specific rotational position of the metering disc316relative to the second housing component108(seeFIG. 1).

With continued reference toFIG. 7, the depth and width of the metering groove344may be decreased along the length of the groove344to provide the capability of low chemical draw rates. However, similar to the select tortuous path portions360, the metering groove344may include select tortuous path portions362having greater widths than adjacent tortuous path portions358to provide a desired flow characteristic at a specific rotational position of the metering disc316relative to the second housing component108(seeFIG. 1). In contrast to metering grooves144and244illustrated inFIGS. 5 and 6, respectively, the portion356of the metering groove344fluidly coupling the inlet portion350and the outlet portion352extends in a straight line and does not include direction changes such as twists and turns. Different applications might have differing geometries of the metering groove344such that the fineness of the adjustment falls in a certain range of adjustment. For example, the geometry of the groove344was designed to produce the desired increments in the metering curve illustrated inFIG. 14.

The metering grooves144,244,344may be shaped to account for different viscosities of chemical. Thicker and colder chemicals flow less, and thus in order to get the same amount of chemical draw the width of the grooves144,244,344may be increased, which may produce wider spacing between the draw rates. The design of the metering disc116,216,316may be a compromise for the many viscosities of chemical. For example, as the flows are increased, the adjustment fineness may be decreased (i.e., the incremental increase in chemical from one setting to the next setting is increased) to account for the less precision that is required with higher chemical flows and that as viscosity increases the flow between settings decreases. A higher viscosity chemical typically has a higher setting (i.e., outlet104is positioned closer to the inlet portion of the metering groove) than a lower viscosity chemical to achieve the same flow rate.

FIG. 8is a schematic illustration of a dilution device400integrated into an eductor470. In operation, motive fluid such as high pressure water may be received into the eductor470through a motive fluid inlet472for mixing with a concentrated chemical such as a concentrated car-wash chemical received through a chemical inlet474to dilute the concentrated chemical. The motive fluid inlet472may be fluidly coupled with a water source via tubing, piping, or the like via a quick connect coupling, for example. The chemical inlet474may be fluidly coupled with a chemical source via tubing, piping, or the like via an inlet nipple, for example. The dilution device400may be adjustable to regulate the metering of chemical for mixing with the motive fluid to achieve a desired dilution ratio. As illustrated inFIG. 8, the dilution device400may include a user engagement feature428, such as a metering adjustment dial including alternating ridges and grooves for grasping by a user's fingers, to facilitate a user in adjusting the amount of chemical to be mixed with the motive fluid per unit of time. The mixed chemical solution may exit the eductor470through an outlet478, which may be fluidly coupled with an applicator, such as a spray nozzle, via tubing, piping, or the like.

FIGS. 9 and 10illustrate cross-sections of the dilution device400and the eductor470ofFIG. 8. In operation, motive fluid travels through the motive fluid inlet472and through a nozzle480to create a vacuum area482downstream of the nozzle480. Concentrated chemical is drawn through the chemical inlet474(seeFIG. 9), a chemical inlet channel484formed in the eductor470, a metering groove444(e.g., metering groove144,244,344illustrated inFIGS. 5-7) formed in the dilution device400, and a chemical outlet channel486(seeFIG. 9) formed in the eductor470into the vacuum area482via a suction force generated by motive fluid traveling through the nozzle480. The concentrated chemical is mixed with the motive fluid in the vacuum area482and then the diluted chemical solution exits the eductor470through the outlet478, which may be fluidly coupled with an applicator, such as a spray nozzle, via tubing, piping, or the like. Although not shown inFIG. 10, a replaceable filter element may be located in the chemical inlet474to restrict passage of chemical particulates to prevent clogging of the metering groove444.

The eductor470may be configured as a Venturi-style apparatus, such as the Venturi eductor of U.S. Pat. No. 8,807,158. The eductor470may define a Venturi throat488and a diverging outlet passageway490to allow a combination of motive fluid and chemical to be conducted away from the eductor470for dispensing. The Venturi throat488may define a cross-sectional diameter that is less than the cross-sectional diameter of the outlet passageway490. As a result, the motive fluid velocity may increase when passing through the Venturi throat488and decrease after exiting the Venturi throat488. Consequently, pressure within the Venturi throat488may decrease, forming a first pressure zone upstream of the Venturi throat488and a second pressure zone within it. The fluid pressure within the first pressure zone may be higher than that in the second pressure zone. The low pressure within the Venturi throat488may create a suction force that draws concentrated chemical into the vacuum area482, where the chemical mixes with the motive fluid. The concentrated chemical and motive fluid may converge at a perpendicular angle within vacuum area482of the eductor470. The resulting mixture may then pass through the diverging outlet passageway490of the eductor470.

With continued reference toFIGS. 9 and 10, the dilution device400may be axially aligned with the eductor470. The dilution device400may define a central aperture for receiving the eductor470such that the dilution device400is mounted onto the eductor470. The dilution device400may be coupled with the eductor470in various manners. In certain implementations, a retaining element, such as a spiral retaining ring492, may be circumferentially arranged on a portion of the eductor470to couple the dilution device400to the eductor470.

The dilution system illustrated inFIGS. 10 and 11may include one or more sealing elements to restrict leaks between the dilution device400and the eductor470. For example, two sealing elements494may prevent leakage of chemical out of the dilution system. The sealing elements494may prevent, for example, a vacuum leak in the case the metering disc416is not sealed perfectly to a base496of the eductor470. The sealing elements494may be O-rings in circumferential engagement with opposing circumferential surfaces of the eductor body496. One of the sealing elements494may be in circumferential engagement with an internal surface of the metering disc416and the other of the sealing elements494may be in circumferential engagement with an external surface of the metering disc416. As illustrated inFIG. 9, one of the sealing elements494may be circumferentially arranged about a quick connect stem of the eductor470to provide a seal between the quick connect stem and the metering disc416. The other of the sealing elements494may be circumferentially arranged about the metering disc416to provide a seal between the metering disc416and an annular rim of the eductor470that confronts the external circumferential surface of the metering disc416. The number and location of the sealing elements494may vary.

As illustrated inFIG. 9, the dilution device may include a pressure plate498that provides uniform pressure to the metering disc416from a biasing element, such as wave spring448. The dilution device may include a pressure ring499that holds the spring448in contact with the pressure plate498. The pressure ring499may be retained in place by the spiral retaining ring492.

As illustrated inFIG. 10, the eductor470may include a removable inlet nipple501for connecting to a supply chemical. The inlet nipple501may include an inlet filter to prevent clogging the metering groove444. As illustrated inFIG. 10, the cross-sectional area of the metering groove444may change from side A to side B. For example, as shown inFIG. 10, the cross-sectional area of the metering groove444may be reduced as the groove444extends around the metering disc444from side A to side B. To fluidly connect the chemical inlet474to the chemical inlet channel484that is in fluid communication with the metering groove444, the chemical inlet channel484may be formed as an annulus designed to transfer chemical to the inlet portion450of the metering groove444of the metering disc416around the eductor body496. The annular shape of the chemical inlet channel484may ensure that the inlet portion450of the metering groove444is in fluid communication with the chemical inlet474regardless of the rotational position of the metering disc416.

FIG. 11is a schematic illustration of an exploded view of the integrated dilution device and eductor ofFIG. 8. As illustrated inFIG. 11, the dilution system can include a pressure plate498, a wave spring448, a metering disc416, and an eductor body496. The eductor body496includes a flat conforming mating surface420that confronts a corresponding surface442of the metering disc defining the metering groove444to form a flow channel therebetween. The eductor body496may be made from conformable material, such as HDPE, and the metering disc416may be injection molded from various materials, such as HDPE, Kynar, or a similar material. The profile of the metering groove444may include a semi-circular cross-sectional shape for injection molding purposes (e.g., mold release and shape control of the groove). To prevent mold sink, the walls around the metering channel may be thin and uniform. Also, the walls around the metering channel may include a stepped type construction to increase the pressure on the interface between the metering disc and the eductor body proximate the metering groove. A small ridge may be molded around the metering groove, and the ridge may protrude from the compliant flat sealing surface of the metering disc and around the edges of the metering groove. The ridges may be designed to deform the soft HDPE body of the eductor and provide a superior seal of the pressure plate to the eductor body around the metering groove, thereby inhibiting leakage in this area to achieve the lowest draw rates. Similarly on the back side of the metering disc where it touches the pressure plate, this area443has been slightly raised to contact the pressure plate over a small area above the metering groove444, causing a slight deformation in the thin walls of the metering disc in this area and helping the ridges around the metering groove to be in full contact with the flat sealing surface of the eductor body. The dilution device may include sealing elements, such as O-rings1and2,494a,494b, to prevent vacuum leaks from escaping around the pressure plate, thereby maintaining the vacuum in the eductor470to help draw chemical through the metering groove, reduce chemical leak, and press the pressure plate down (with atmospheric pressure) against the flat sealing surface of the eductor body.

FIG. 12is a schematic illustration of metering disc416of the integrated dilution device400and eductor470ofFIG. 8. As illustrated inFIG. 12, the metering disc416may include a metering groove444formed in a flat sealing surface442. The metering groove444may be in fluid communication with a chemical inlet channel484(seeFIG. 13), which may include an annular portion to ensure the metering groove444remains in fluid communication with the chemical inlet474(seeFIGS. 9 and 10) regardless of the angular position of the metering disc416relative to the eductor body496. The metering disc416may include a user engagement feature428, as previously discussed.

FIG. 13is a schematic illustration of the eductor body496of the dilution system ofFIG. 8. As illustrated inFIG. 13, the eductor body496may include a flat sealing surface420that sealingly engages the sealing surface442of the metering disc416illustrated inFIG. 12. The sealing surface420may be softer than the sealing surface442, such that ridges146(seeFIG. 3B) extending along edges of the metering groove444(seeFIG. 12) may depress the sealing surface420to form a fluid-tight seal along the edges of the metering groove444. As illustrated inFIG. 13, the chemical inlet channel484is defined in the eductor body496. The chemical inlet channel484fluidly couples the inlet portion450of the metering groove444(seeFIG. 12) with the chemical inlet474(seeFIG. 10) regardless of the angular position of the metering disc416(seeFIG. 12) relative to the eductor body496via an annular recess497formed along an inner periphery of the flat sealing surface420. As further illustrated inFIG. 13, the chemical outlet channel486is defined in the eductor body496. The chemical outlet channel486opens through the flat sealing surface420radially outward of the annular recess497. The chemical outlet channel486is in fluid communication with the outlet portion452of the metering groove444(seeFIG. 12). A suction force created in the vacuum area482of the eductor body496(seeFIGS. 9 and 10) via the motive fluid draws the chemical through the metering groove444(seeFIG. 12) and the chemical outlet channel486in the eductor body496for mixing with the motive fluid in a cavity defined in the eductor body496.

FIG. 14is a graph comparing performance of the metering disc316(seeFIG. 7) incorporated into the dilution device100(seeFIG. 1) and a prior art metering orifice.FIG. 14illustrates the results of a laboratory test of the metering disc316using water drawn by a 3.25 gallons per minute (GPM) eductor operating at 200 psi inlet pressure and 114 degrees Fahrenheit water temperature. The lower line in the graph illustrates the results of prior art metering orifices that are commonly available and in wide use for chemical metering, and the upper line in the graph illustrates the results of the metering disc316. As illustrated inFIG. 14, the metering disc316(upper line) provides more disc settings than the prior art metering orifices over the same range of water flow rate, thereby providing more accurate adjustment of chemical flow over the illustrated range of values.

In certain implementations, the dilution device may be adjustable in an automatic fashion, rather than by human intervention. For example, the dilution device may be automatically adjusted based on a feedback loop signal received from a control system monitoring characteristics of the chemical, the dilution device, and/or the motive fluid. The control system may monitor, for example, the amount of fluid flowing through the dilution device, the concentration of chemical in the emitted fluid mixture downstream of the dilution device, and/or an output of a chemical delivery system. In certain implementations, the control system may monitor the potential of hydrogen (pH) of the diluted fluid, the total dissolved solids (TDS) concentration of the diluted fluid, and/or the conductivity of the diluted fluid. A control system for measuring the amount of fluid flowing through the dilution device may include, for example, a volumetric flow meter, a scale, a mass flow meter, a measurement on a filled volume, and/or a timing of the amount of fluid through an orifice or nozzle. The feedback loop may be managed either electrically or mechanically. In certain implementations, the control system may include a controller, such as a computer, configured to automatically manage the feedback loop.

The control system may adjust the output of the dilution device based on a measured condition. For example, in certain implementations, the dilution ratio downstream of the dilution device is monitored, and the control system automatically adjusts the dilution ratio of the dilution device real time to compensate for dilution ratios downstream of the dilution device that are too rich or too lean relative to a desired ratio. For example, changes in temperature may cause changes in chemical viscosity, which may affect flow of chemical through the dilution device for mixing with the motive fluid, thereby affecting the dilution ratio. The control system may adjust the dilution device to maintain a constant chemical flow rate through the device despite changes in chemical viscosity, thereby maintaining a desired chemical concentration in the emitted fluid mixture.

In another example, when chemical is diluted in water, different water hardness levels may require more or less chemical in solution to effectively clean a surface because many chemicals react with the hardness in the water, resulting in a less potent solution. Water hardness may change frequently for a given water supply, such as municipality water in a given geographic location. In response to an increase in the hardness of the water, the control system may increase the amount of chemical added to the water to compensate for some chemical reacting with the hard water.

In a further example, environmental conditions may affect the chemical levels. For example, the control system may adjust the amount of chemical delivered to the motive fluid based on environmental conditions. In certain implementations, the control system may adjust the amount of chemical based on the condition of the targeted surface, such as the amount of soil on the surface, the type of soil on the surface, and/or the temperature of the surface. The control system may adjust the amount of chemical for a surface that is particularly soiled, has a particular type of soil upon it, and/or is hot, among other environmental conditions. By adjusting the amount of chemical based on environmental conditions, the control system may control the dilution device to create a diluted chemical concentration for effectively cleaning the targeted surface.

FIG. 15is a schematic illustration of a control system for automatically adjusting the dilution ratio of a dilution device, such as the dilution devices previously described. As illustrated inFIG. 15, the control system513includes an actuator515for selectively rotating a metering disc516, which may be configured and may function similar to the previously described metering discs116,216,316,416. The actuator515may be coupled with a pawl519and may move (e.g., cycle) the pawl519to selectively engage and rotate the metering disc516to adjust the flow of chemical through the dilution device. InFIG. 15, an initial position of the pawl519is illustrated in solid line and an extended position of the pawl519is illustrated in dashed line, thereby illustrating the stroke of the pawl519that causes the metering disc516to rotate accordingly. The actuator515may be an electric solenoid, air cylinder, or other actuator capable of moving the pawl519to selectively engage and rotate the metering disc516. The actuator515may receive an input signal523, such as an electrical or air signal, that causes the actuator515to move (e.g., cycle) the pawl519and rotate the metering disc516to adjust the dilution ratio. The input signal523may be based on monitored conditions as previously discussed, and the actuator515may cycle the pawl519based on the monitored conditions to rotate the metering disc516to its desired setting.

The metering disc516may include an engagement feature, such as teeth521, for engagement by the pawl519. Each tooth521of the metering disc516may correspond to a different chemical setting (e.g., a different flow path between an inlet and outlet of the dilution device), thereby providing different dilution ratios depending on the rotational position of the metering disc516. The metering disc516may include various numbers of teeth521depending on the desired number of settings.

The control system513illustrated inFIG. 15is configured to advance the metering disc516in one rotational direction as represented by arrow525, and thus the flow rate of chemical is incrementally adjusted from one setting to an adjacent setting until the desired setting is achieved. For example, for a metering disc including thirty-two settings (e.g., thirty-two teeth) and a pawl configured to incrementally advance the metering disc to a next larger setting, the metering disc would have to be advanced thirty-one times to go to the next smaller setting.FIG. 16is a schematic illustration of another control system613similar to the control system513illustrated inFIG. 15, but, in contrast to the control system513illustrated inFIG. 15, the control system613illustrated inFIG. 16is configured to rotate a metering disc616(such as metering discs116,216,316,416) in either direction, as represented by arrows625. The control system613may include two actuators515and pawls519, which may be the same or substantially the same as those used in control system513. The actuators515and pawls519in control system613may be positioned to engage opposite faces of the teeth621of the metering disc616relative to each other, thereby rotating the metering disc616in opposite directions when the respective pawls519are actuated. The respective actuators515may receive respective input signals523to control movement of the pawls519and thus rotation of the metering disc616. The metering disc616may include teeth621configured such that the metering disc616can be advanced in either direction. In other words, the metering disc616may be rotated either clockwise or counterclockwise to achieve a desired setting. The teeth621may be symmetrical to facilitate engagement by either of the pawls519, whereas the teeth521inFIG. 15may be asymmetric.

FIG. 17is a schematic illustration of a control system713with continuous adjustment, in contrast to the control systems513,613illustrated inFIGS. 15 and 16with discrete adjustment intervals. As illustrated inFIG. 17, the metering disc716(which may be configured and may function similar to the previously described metering discs116,216,316,416) is adjustable in an analog setting so that any rotational position (and thus chemical flow value) may be obtained, rather than the step by step adjustment of control systems513and613. As illustrated inFIG. 17, the metering disc716may be driven by an actuator, such as motor727, with a gear729that engages teeth721on the metering disc716. The motor727can rotate the metering disc716in either direction, as represented by arrows725inFIG. 17, via the gear729to adjust the rotational position of the metering disc716to the desired setting. The motor727may receive the input signal523to cause the motor727to rotate the gear729, thereby rotating the metering disc716to adjust the dilution ratio based on, for example, the monitored conditions previously discussed.

As illustrated inFIG. 17, the control system713may include a locating sensor731to determine the rotational position of the metering disc716. The locating sensor731may be a proximity switch that counts the number of teeth721on the metering disc716as respective teeth721pass by the sensor731, and therefore the control system713can determine the location of the metering disc716. The locating sensor731may be an optical encoder, a variable resistor, and/or other components capable of determining or facilitating determination of the location of the metering disc716. Although not illustrated inFIGS. 15 and 16, the locating sensor731may be added to the control systems513,613.

The locating sensor731may be in communication with a computer via signal733to ensure the metering disc716is in its desired location. Adjustment of the rotational position of the metering disc716may be in response to a feedback loop or in response to known changing conditions. For example, the actuator associated with the metering disc716may be used to move the disc716until locating sensor731indicates the metering disc716is at a predetermined positon. This repositioning may be performed on a predetermined schedule or when an external condition, such as temperature, changes. For example, when a dirty cleaning surface is encountered, the position of the disc716may be set to deliver a greater amount of chemical. Another example is the disc716may be moved to deliver less chemical on a timed schedule in order to change the chemical delivery based on known conditions such as excessive bugs on the front of a car and fewer on the rear of the car. Thus, more chemical may be applied to areas of expected greater soil.

FIG. 18is a schematic illustration of another dilution device800configured for dispensing fluid. In various implementations, the dilution device800may comprise a metering device configured for dispensing car wash solution. As shown inFIG. 18, the dilution devices disclosed herein may be configured to input and output fluids from multiple directions relative to an internal metering component. As a result, the devices can be mounted in various positions and thus compatible with various dispensing systems. The dilution device800includes an inlet nozzle802and an outlet nozzle804. The inlet nozzle802may be in fluid communication with a chemical, which may be stored in a chemical container at atmospheric pressure. The outlet nozzle804may be in fluid communication with the inlet nozzle802via a flow channel. The outlet nozzle804also may be in fluid communication with a chemical mixing device, such as an eductor. For example, the outlet nozzle804may be fluidly coupled with a chemical inlet of an eductor. In some examples, the connection between the eductor and outlet nozzle804may be of a barbed hose type, quick connect, or other means. In certain implementations, the chemical inlet of the eductor typically draws about 25 to 28 inches of mercury (inHg) of vacuum with an inlet water pressure of about 200 pound force per square inch (psi). The difference between the vacuum in the eductor and the atmospheric pressure at the inlet nozzle802creates a pressure differential that draws chemical through the dilution device800.

As illustrated inFIG. 18, the dilution device800may include a first housing component806and a second housing component808. The first housing component806may function as a cover for the second housing component808. In certain implementations, the first housing component806may be formed as a rounded plate or molded component. Furthermore, the inlet nozzle802and the outlet nozzle804may be coupled with a chemical container and an eductor, respectively, via a flexible hose in some examples, such as the flexible hose811shown partially inserted into the inlet nozzle802inFIG. 19. The connections may be provided as an integral part of the dilution device800joined by mechanical means of threading, welding, or other adhesion. The outer surface810may be planar (i.e., flat) or rounded, and may be formed of machined polyethylene in some examples. The outer surface810may also be formed to provide attachment to an integrated panel system for storage and removal for adjustment. In the example shown, the inlet nozzle802and the outlet nozzle804are positioned on opposite surfaces around the circumference of the device800, such that the nozzles protrude radially outward and away from each other along approximately the same lateral plane.

FIG. 19is a schematic illustration of an exploded view of the dilution device800. As shown, the dilution device800can include a metering component, such as a metering disc816. The metering disc816may be received in a cavity818formed at least partially in the second housing component808. In a similar fashion, the metering disc816may be received in a cavity formed in the first housing component806. The inlet nozzle802and the outlet nozzle804may open through an interior surface820of the second housing component808into the cavity818. The interior surface820may be planar (i.e., flat) in various embodiments. The metering disc816may sealingly engage the second housing component808to maintain fluid flow between the inlet nozzle802and the outlet nozzle804with little to no leaking. For example, a sealing element894may be retained in a groove822formed in a circumferential surface824of the metering disc816, such that the sealing element894may engage a corresponding circumferential surface826of the second housing component808to form a fluid-tight seal between the metering disc816and the second housing component808. A second sealing element895, e.g., O-ring, may also be included to seal the cavity818. The circumferential surface826may extend orthogonally to the interior surface820. The interior surface820may form a fluid-tight seal with a corresponding surface of the metering disc816, as described in more detail below. In some embodiments, the first housing component806and the second housing component808may also be coupled together by means of a snap fit or other mechanic retention. As further shown, a replaceable filter element813may be located in or coupled with the first nozzle802to restrict passage of chemical particulates and prevent clogging of the metering groove, e.g., metering groove844ofFIG. 20.

The metering disc816may be rotatable relative to the first housing component806, the second housing component808, or both. As illustrated inFIG. 19, the device800may include at least one adjustment feature configured to facilitate rotating the metering disc816relative to the second housing component808. For example, a user engagement feature828, such as the illustrated adjustment slots, may be accessible through an aperture830formed through the first housing component806. One or more user actuation features, e.g., interlocking tabs829, may also be incorporated into the first housing component806, and may be manipulable via manual actuation. To adjust the position of the metering disc816, the tabs829can be engaged with the corresponding slots828and rotated, thereby modifying the outlet portion segment through which fluid is dispelled from the metering groove (see e.g., metering groove844inFIG. 20). Via such adjustment features, the metering disc816may provide continuous or discrete adjustment relative to the second housing component808depending on, for example, the particular geometry of the metering groove defined by the metering disc816. Additional user engagement features and user actuation features may be included in additional embodiments. For example, a user actuation feature may include a pin configured for insertion into a user engagement feature comprised of a complementary slot. Alternatively, a user engagement/actuation feature may comprise a lockable push-button/aperture combination.

The metering disc816may be biased toward the second housing component808. For example, a surface842of the metering disc816may be biased into engagement with the interior surface820of the second housing component808to facilitate a fluid-tight seal between the two components. As further illustrated inFIG. 19, a biasing element849may bias, e.g., press, the metering disc816between the surface820of the second housing component808and an inner surface of the first housing component806to promote sealing between the surfaces820,842. The biasing element849may be coupled to the second housing component808and can at least partially surround the aperture830such that the biasing element849does not interfere with adjustment of the metering disc816relative to the second housing component808. Similarly, an elastomer material, such as a closed cell foam, may be used to bias the metering disc816toward the second housing component808. The biasing element849may engage with the second housing component808to ensure fluid flow through the metering disc816is directed as needed from the inlet nozzle802to the outlet nozzle804.

FIG. 20shows the metering disc816, including the metering groove featured in this specific example. As shown, the metering disc816defines a metering groove844that originates at an inlet portion850and terminates at an end portion854. The metering disc816also defines an enlarged outlet interface on surface842at the outlet portion segments852, which may allow for increased range in adjustment of the first housing component806to achieve accurate output flow at specifically desired rates. The metering groove844defines a tortuous portion858fluidly coupling the inlet portion850and the outlet portion segments852. As shown, the tortuous portion858extends in straight lines that do not include arcuate direction changes, e.g., twists and turns; however, different applications can have differing geometries of the metering groove844.

FIG. 21is a graph comparing performance of the metering disc816incorporated into the dilution device800and a preexisting metering orifice. The graph illustrates the results of a laboratory test of the metering disc816using water drawn by a 3.25 gallons per minute (GPM) eductor operating at 200 psi inlet pressure and 78 degrees Fahrenheit water temperature. The upper line in the graph illustrates the results of prior art metering orifices that are commonly available and used for chemical metering, and the lower line in the graph illustrates the results of the metering disc816. As illustrated inFIG. 21, the metering disc816disclosed herein provides more disc settings than preexisting metering orifices over the same range of water flow rates, thereby providing more accurate, refined adjustment of chemical flow over the illustrated range of values.

Various components of the dilution system may be integrally constructed. The integral construction may, for instance, be by molding (e.g., injection molding) a chemically inert polymer such as HDPE, PTFE or PVDF. At least some components of the dilution system may be constructed of inert polymers, while others may be constructed of metal, such as spring clips, helical springs, and inlet connectors. To decrease the cost of the parts and/or improve chemical resistance, components of the dilution system may be molded from a plastic material. These components may additionally or alternatively be machined or additive manufacturing may be used for their construction. The dilution devices and system described herein may be particularly useful in the car wash and industrial cleaning industries. The dilution devices and systems described herein may be applicable to other industries as well. For example, changing the dilution of drugs delivered to a patient on a schedule that keeps a constant blood concentration level.

Although certain embodiments of the present disclosure are described herein with reference to the examples in the accompanying figures, it would be apparent to those skilled in the art that several modifications to the described embodiments, as well as other embodiments of the present invention are possible without departing from the spirit and scope of the present disclosure.