JP2023544995A - Manifold compatible ozone electrolyzer (EO cell) with coplanar fluidic and electrical connection scheme - Google Patents

Abstract

The ozone electrolyzer includes a housing that includes an interface seal, a top plate, and a bottom plate. The ozone electrolyzer also includes an internal compartment with a pair of contact plates and a tolerance compressor. A tolerance compressor compresses an electrode-membrane-electrode stack disposed between a pair of contact plates, and the tolerance compressor changes its shape to maintain a compressive force on the electrode-membrane-electrode stack.
[Selection diagram] Figure 2

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit and priority of U.S. Provisional Patent Application No. 63/086,218, filed October 1, 2020, which is incorporated herein by reference for all purposes.

TECHNICAL FIELD This application relates generally to ozone electrolysers. More specifically, this application relates to a low profile ozone electrolyzer having fluid and electrical connections coplanar with the manifold assembly.

Ozone is a highly reactive gas composed of three oxygen atoms (O3). Ozone occurs naturally in the Earth's atmosphere, with highest concentrations in the stratosphere, where it acts as a filter for ultraviolet light. Ozone is a highly effective antimicrobial agent and has been used in medical applications, including disinfection and sterilization products. Gaseous ozone causes oxidation reactions on the cytoplasmic membranes and cell walls of bacteria. The resulting damage to the bacterial cell walls increases the accumulation of ozone within the cells, which forms free radicals that destroy the bacteria. This helps improve oral health and broader systemic health, including reducing the risk of tooth decay, gingivitis and periodontitis, bad breath, cardiovascular disease, stroke, hyperglycemia, and other diseases. Significant benefits can be achieved for.

Exemplary embodiments provide a system suitable for forming ozone dispersed in a liquid, such as water, suitable for use in dental products such as dental ultrasonic scalers.

In one aspect, an ozone electrolyzer includes a housing that includes an interface seal, a top plate, and a bottom plate. The ozone electrolyzer also includes an internal compartment including at least a pair of contact plates and a tolerance compressor for compressing an electrode-membrane-electrode stack including a pair of electrodes and at least one proton exchange membrane; The electrode stack is disposed between a pair of contact plates, and a tolerance compressor changes dimensions of the tolerance compressor in response to thinning of the proton exchange membrane to maintain a compressive force on at least the electrode-membrane-electrode stack. It is configured as follows. In one embodiment of an ozone electrolyzer, the electrode-membrane-electrode stack includes one or more electrode pairs within the same cell. One or more pairs may each be independently controllable.

The ozone electrolyzer may also include configured to be coupled to the manifold assembly of the ozone aqueous ultrasonic scaler system such that the electrolyzer housing has a coplanar interface with the manifold surface.

The pair of contact plates may be titanium (Ti) contact plates. The pair of electrodes may be boron doped diamond (BDD) electrodes. The electrodes of the pair of electrodes can be perforated silicon plates with a boron-doped diamond coating. A pair of electrodes and the proton exchange membrane may form an electrode-membrane-electrode stack, and the tolerance compressor provides compression for the electrode-membrane-electrode stack over a range of 2-50% of the thickness of the tolerance compressor. I will provide a.

Additionally, the tolerance compressor may be ozone inert. Tolerance compressors may also be made from closed cell ethylene propylene diene monomer (EPDM) foam material. The path for water flow may be based on the contact plate thickness and internal profile of the pair of contact plates.

The ozone electrolyzer may include two or more pairs of electrodes. The electrical contact areas of the contact plates of the pair of contact plates can be accessed through the top plate by spring-loaded electrical contacts such that the contact plates supply current to the electrodes of the pair of electrodes. The contact plate and electrode may be integrated to form an electrode unit that provides direct electrical contact for spring-loaded electrical contacts. The bath may be configured to control the rate of water flowing through the bubble formation region along the three-phase boundary (TPB) formed by the electrode-water-membrane interface. Other technical features may be readily apparent to those skilled in the art from the following figures, description, and claims.

In one aspect, an apparatus may be formed that includes a water source for delivering water to an ozone electrolyzer. The apparatus also includes a gas separator located in the recirculation loop of the fluid path that also includes the electrolytic cell. The apparatus also includes an ozone electrolyzer. The ozone electrolyzer further includes a housing that includes an interface seal, a top plate, and a bottom plate. The ozone electrolyzer of the apparatus further includes an internal compartment including at least a pair of contact plates and a tolerance compressor for compressing an electrode-membrane-electrode stack including a pair of electrodes and at least one proton exchange membrane; The membrane-electrode stack is disposed between a pair of contact plates, and a tolerance compressor is configured to adjust the dimensions of the tolerance compressor in response to thinning of the proton exchange membrane to maintain at least a compressive force on the electrode-membrane-electrode stack. configured to change.

In one aspect, a computer system is formed. The computer system includes a processor configured to control operation of the ozone electrolyzer. The computer system also includes an ozone electrolyzer. The computer system also includes an ozone electrolyzer further including a housing including an interface seal, a top plate, and a bottom plate. The ozone electrolyzer of the computer system further includes an internal compartment including at least a pair of contact plates and a tolerance compressor for compressing an electrode-membrane-electrode stack including a pair of electrodes and at least one proton exchange membrane; - the membrane-electrode stack is arranged between a pair of contact plates, and a tolerance compressor is configured to reduce the pressure of the tolerance compressor in response to thinning of the proton exchange membrane in order to maintain a compressive force on at least the electrode-membrane-electrode stack; Configured to change dimensions. Other technical features may be readily apparent to those skilled in the art from the following figures, description, and claims.

More specifically, aspects herein disclose a manifold compatible ozone electrolysis (EO) cell having a coplanar fluidic and electrical connection scheme. EO baths can be designed for use in both dental and medical applications. A vessel as described herein may communicate with a broader system via a coplanar connection scheme. The thin stacked layers of the vessel are assembled to form a low profile assembly. The vessels are designed to communicate through fluid and electrical ports located in one single plane of the vessel. The low-profile design and coplanar connection scheme provide a form factor that is easily accessible for maintenance and helps limit the overall footprint and form factor of the medical device.

An example of an application for such an electrolytic cell is the production of aqueous ozone solutions in dental ultrasonic scalers. Such scalers include closed system water delivery and an integrated in-line electrolytic ozone generator, gas separation, and in-line dissolved gas monitoring to enable closed-loop control of ozone concentration. The EO bath enables ultrasonic scaling units with the ability to generate aqueous ozone (AO) on demand, addressing an important market barrier. Ultrasonic scaling systems that utilize an aqueous ozone irrigation solution facilitate removal of dental biofilm for more complete debridement. The aqueous ozone solution will be delivered to the oral cavity through an ultrasonic scaler handpiece and insert controlled by an ultrasonic scaling unit.

A fully integrated system with in-line aqueous ozone generation allows aqueous ozone to be generated and used within the treatment room when needed for dental or medical procedures. The materials used in the fluid paths for both the aqueous ozone generator and the scaler limit both scavenging, ensure material compatibility with dissolved ozone, control the concentration of cleaning fluid exiting the scaling equipment, and the equipment. can be controlled and designed to ensure the effectiveness and reliability of the Integrating the ozone generator and ultrasonic scaler prevents misuse of aqueous ozone solutions in existing scalers that are potentially ozone incompatible.

Dental practitioners can use the ultrasonic scaling unit with or without generating an aqueous ozone solution. The ability to simply stop ozone production or reduce ozone production to maintain the cleanliness of the water lines allows the clinician to control the timing of delivery of the aqueous ozone solution to the patient.

Manifold compatible EO vessels as described herein have several advantages. By communicating with the manifold through a coplanar interface, all fluidic and electrical connections can be made by securing the EO reservoir to the surface of the manifold, eliminating additional interconnecting parts, reducing size, and increasing reliability. improve performance and create a more easily accessible and maintainable design. Additionally, the tank construction utilizes tolerance compressor elements that manage both minimum and maximum material requirements and film thickness reduction over the life of the tank.

Form Factor Ultrasonic scalers are typically placed on a countertop, in a cabinet, or in a special drawer designed for surgical instruments. These standard installation locations for scalers require that any new scaler, regardless of technology, have the required shape and fit into the existing treatment room. This implementation consideration determines the overall industrial design of the scaler, its height, and footprint. As a result, the internal components used to generate and control the AO solution must be small. Manifold compatible EO vessels provide such a low profile form factor while allowing easy access through a service door or panel on the scaler housing for use.

Optimal flow rate for EO tank design (bubble removal via restricted channel flow path)
The bath design also controls the velocity of water flowing through the bubble formation region along the three-phase boundary (TPB) formed by the electrode-water-membrane junction. The tank design directs water over the TPB at an ideal rate based on the system internal recirculation flow rate. A lower flow rate in the recirculation path throughout the system reduces wear and tear on the system's water pump, minimizes turbulence at the gas separator, and gravity and laminar flow prevents air bubbles from re-entering the recirculation path or Directly supports the ability of the gas separator to prevent migration from exiting the system and into the scaler handpiece. Preventing air bubble recirculation improves the accuracy of UV sensors that utilize the absorption properties of dissolved ozone molecules to quantify the concentration level of aqueous ozone solutions. Air bubbles that move past the UV sensor tend to scatter light and add noise to the UV sensor measurements. The efficiency of a system that converts electrical current into an aqueous ozone solution, in addition to mechanical wear and recirculation pumps, is directly related to system reliability. The tank design can minimize recirculation flow and limit mechanical degradation of ozone molecules by controlling and optimizing the flow rate through the tank. Mechanical pumping and recirculation of the AO solution aids in the decomposition of O3 to the more stable oxygen state O2. Therefore, efficient cell operation at lower recirculation flow rates improves overall system efficiency, reduces demand and cell current density, and increases reliability of the EO cell and the overall system.

An important parameter is the flow rate within the tank. The flow rate is primarily controlled by the combination of flow rate and the gap above the electrode or bubble removal gap. Vessels designed for high volumetric throughput (e.g., 1 liter/min or higher) may have large bubble removal gaps, but these vessels do not provide the desired amount of gas while also removing undissolved gas from the exhaust fluid stream. Not optimized for systems that recirculate aqueous ozone solutions using lower flow rates to achieve and control concentrations. Higher volumetric throughput baths have flow velocities across the electrodes of about 1 m/s, and at higher flow rates air bubbles can be effectively purged from the TPB. The exact values required to purge gas from the TPB depend on the electrode surface geometry, gap size versus bubble size, and the current density at which the bath is operated also determines the growth rate and amount of gas production.

For example, assume a flow velocity of 1 m/sec across the face of the tank and calculate this based on the channel geometry and volumetric flow rate. A flow path across the electrodes of width 5 mm and height 0.1 mm has a nominal flow velocity easily estimated and a cross-sectional area of (0.5*0.01) cm2 = 0.005 cm2.

In this very narrow gap, flow velocities are greater than 1 m/s, even at much lower recirculation flow rates than 200 ml/min.

Therefore, the reduction of the bubble removal gap favors a recirculation flow rate of <100 ml/min from a bubble removal point of view. Besides the bubble removal aspect, the effect of the flow rate on the separator is considered to prevent air bubbles from entering the outlet and being recirculated while also mixing the nascent AO solution with the volume of fluid in the separator. The interaction between the recirculation flow rate and the concentration averaging timescale in the separator depends on what concentration fluctuation behavior is allowed, which also depends on the flow rate in the separator during the evacuation of the AO solution from the handpiece. It depends on what refill cycle is used to maintain fluid levels.

Gas accumulation caused by the entrapment of air bubbles within the flow path of the reservoir can occur if the flow rate through the reservoir becomes too low in the electrode area. The water flow must also remove heat from the bath, so in the limit of low flow rates the effect on the bath internal temperature must be considered, and this also affects the adjustment of the bath current, and the dual electrode vs. Mitigation is achieved by switching pairs of vessels in the configuration. EO baths may not have a pure cross-flow, so there may be a "vortex" around the periphery that can trap some air bubbles, but most of the electrode area is well flushed by the flow. be done. The orientation of the vessel such that its discharge port terminates at the bottom of the manifold aids in bulk bubble formation, releasing gas buildup outside the flow path, and this bulk bubble formation is responsible for the recirculation flow of both systems, the separator Movement occurs both due to interruptions in recirculation during the filling cycle and due to the effects of gravity.

Additionally, the lower recirculation flow rate creates a quieter product by limiting both motor and pump noise in dental procedures.

Reliability Eliminating additional interconnect components directly helps improve reliability. A single interface seal for one fluid port replaces two fittings, each having two connections that are rigid tubular interfaces. Four potential leak points per fluid port can be addressed by a single precision coplanar connection. The vessel will typically have four fluid ports (anode in/out and cathode in/out) creating the possibility of fluid leakage. To demonstrate improved reliability, each connection is assumed to have 99.0% reliability over the product's service life without redundancy. This reliability must be considered for each fluid connection in the system used to terminate the bath (4 ports, 8 fittings, 8 tubes, 8 rigid connections), ( 0.99 ¹⁶ =0.851), which reduces the reliability of the system to 85.1%. The coplanar seal has 4 ports and 4 seals, and assuming the same reliability of 99%, the reliability of the entire tank will be 96%. It can also be said that the nature of the fitting and its dependence on the skill and training of the assembler can influence the overall reliability of the connection (for example, insufficient torque on the fitting, improper installation of the pipe, poor fixation of the tube with the correct sleeve or tube lock). Manifold compatible EO vessels can be inspected and secured using redundant mounting hardware that accommodates compression of the interface seal.

Tolerance Compressor The cell construction utilizes a tolerance compressor that maintains a normal force on the electrode pair to improve reliability and performance of the EO cell. Tolerance compressor elements manage both minimum material requirements, maximum material requirements, thermal expansion, and film thickness reduction over the life of the vessel for the vessel components. In addition to accommodating dimensional variations, the tolerance compressor ensures that the final vessel assembly has sufficient internal compression forces on the electrode-membrane-electrode stack. Clamping force on the stackup ensures proper bath impedance and good contact area on the electrode surface.

To readily identify the description of any particular element or act, the most significant digit in a reference number refers to the figure number in which the element is first introduced. Certain novel features considered characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as its preferred mode of use, further objects and advantages, will be best understood by reference to the following detailed description of illustrative embodiments, when read in conjunction with the accompanying drawings.

1 shows a block diagram of an ozone aqueous ultrasonic scaler system 100 according to one embodiment. FIG. FIG. 2 shows an exploded view of a manifold compatible electrolytic cell according to an example embodiment. FIG. 5 shows an image of internal components of a single electrode pair manifold compatible electrolytic cell according to an exemplary embodiment. 3 shows images of electrodes and membranes according to example embodiments. FIG. 3 shows an image of a membrane with demonstrated degradation and thinning, in accordance with an exemplary embodiment. FIG. FIG. 3 shows images of tolerance compressor elements and electrolyzer cross-sections in accordance with an exemplary embodiment; FIG. 1 illustrates a perspective view of an ultrasonic dental scaler with an integrated ozone generator, according to an example embodiment. FIG. FIG. 3 shows a perspective view of a housing according to an example embodiment. FIG. 3 illustrates top and bottom perspective views of a manifold assembly according to an example embodiment. FIG. 3 illustrates a top perspective view of a manifold assembly according to an example embodiment. FIG. 3 illustrates a bottom perspective view of a manifold assembly according to an example embodiment. FIG. 3 illustrates a bottom perspective view of the manifold assembly showing the location of the electrolytic cells, according to an example embodiment. FIG. 3 illustrates a cross-sectional view of a manifold assembly showing electrical connections of an electrolytic cell, according to an example embodiment. 2 shows an electrolytic cell constructed with two pairs of electrodes, according to an exemplary embodiment. FIG. 7 illustrates a cross-sectional view of a bath showing a bubble removal gap above an electrode, according to an example embodiment. 2 shows a schematic diagram of an electrolyzer footprint with symmetrical fluidic and electrical connections, according to an example embodiment. FIG. 2 shows a schematic diagram of an electrode with tabs providing direct electrical contact, according to an exemplary embodiment; FIG. 1 illustrates a computer system according to an example embodiment.

The exemplary embodiments described herein are directed to manifold-compatible electrolytic ozone (EO) cells with coplanar fluidic and electrical connection schemes. The exemplary embodiment recognizes that in conventional electrolyzers, the purpose is to produce pure hydrogen and high pressures, and therefore a very robust structure is required. This design goal means that it is not suitable for low cost portable equipment. Exemplary embodiments further provide that conventional electrolyzers typically have very low levels of dissolved ozone in solution, the need to avoid releasing excessive gaseous ozone, and the lack of gas management components in the system. , and to achieve their operation at ambient pressure.

FIG. 1 shows a block diagram of a general ozone aqueous ultrasonic scaler system 100 in which an ozone electrolyzer 104 may be incorporated according to one embodiment. The system includes a water source 102 and an ozone electrolyzer 104 that oxidizes water to form ozone in solution. During start-up, the system achieves the specified pressure by two means: the primary water pump 112c and the air pump 112a (or air pump 112b) that forces fluid into the scaler/ultrasonic handpiece 106. Gas separator 110a, gas separator 110b separates gaseous ozone from the water stream delivered to ultrasonic handpiece 106. UV sensor 108 directly monitors the level of ozone in the water. Non-ozonating operations may also be delivered through the ozone generator 114 portion of the system by turning off the current to the ozone electrolyzer 104, the cell current may also be operated at a much lower level, or the ozone The electrical current required to generate it can be pulsed infrequently, resulting in undetectable levels of ozone being delivered to maintain the cleanliness of water lines within the system.

To support form factor and serviceability requirements, the EO bath, for example 0 ppm to 6 ppm, can be completely filled with a dental system within a short period of time (e.g. within 30 seconds) compared to traditional methods. A low profile, manifold compatible ozone electrolyzer 104 is disclosed that minimizes space requirements while delivering ozonated water. This rate of ozone gas production and long lifetime is achieved by maintaining a low current density on the membrane and efficiently ejecting the gas bubbles formed at the three-phase interface (electrode-membrane-water contact). Efficient bubble release is achieved by controlling the velocity of water on the electrode surface. By controlling the cross-sectional area of the electrode area and maintaining both the system pressure (eg, 19-24 psi, typically 22 psi) and the flow rate through to the bath. The rate of water in the bath can be controlled to help remove air bubbles and replenish the TPB with fresh water to continue feeding the electrolysis process.

The system of the present disclosure includes the following main elements. A housing comprised of an interface seal 202, a top plate 204, and a bottom plate 216, which when combined form the body of the ozone electrolyzer 104, defines the dimensions of the internal compartments of the ozone electrolyzer 104 and connects the cell to the manifold surface. providing a means for securing to the wafer, forming an internal fluid path, and providing a coplanar interface for both fluid and current connections. The ozone electrolyzer 104 includes several internal components: a tolerance compressor 206, a contact plate 208 such as a Ti contact plate (titanium contact plate), an electrode 210 such as a BDD electrode (boron-doped diamond electrode), a proton exchange membrane 212, and An inner bottom gasket/seal 214 may be included. BDDs have overvoltages that produce ozone. In alternative embodiments, materials suitable for medical devices may be used. For example, lead oxide produces ozone, but it cannot be used because it is toxic. These internal components include the electrolytic cell, current distribution within the cell, seals to separate internal fluid and gas paths (i.e., anolyte and catholyte), and to maintain sufficient compressive force on the internal assembly. Establish a means of Additional elements may be added without changing the essential elements of the system disclosed herein. Methods and embodiments of each of these elements are detailed herein.

Conventional tanks may also produce some oxygen as a by-product, which further enhances the usefulness of the produced water for treatments targeting anaerobic organisms, whereas AO solutions primarily intended for scaling does not reduce the value of The bath may also produce some hydrogen peroxide, and this component of the solution is also beneficial for cleaning, bleaching and antibacterial effects. In some instances, the synergistic effects of ozone and hydrogen peroxide are known and may be used advantageously by the system.

Electrochemical cells Electrochemical ozone generation by direct oxidation of water, instead of the formation of O3 from O2 as in the gas phase, where the catalytic electrode surface is the site of a network of reactions via several different adsorbed intermediates It is a complex electrochemical process. A network of reactions produces a mixture of oxygen and ozone. Although the chemistry of the catalyst surface influences the rate of ozone production, the oxygen formation pathway is energetically more favorable and typically at least half of the electrode current is required to generate oxygen even on the most ozone-promoting surfaces. Form. Although the relative ozone-to-oxygen formation rates of different catalysts have been extensively studied and large differences have been observed, the microscopic physical chemistry of the process is not completely understood.

Traditionally, the goal has been to achieve the highest possible oxygen production rate (and thus hydrogen production rate) at the lowest achievable cell voltage, as this directly affects the energy cost of the process. Most electrolysis is performed directly using a conductive electrolyte that carries electrical current between electrodes. However, proton-conducting membranes that carry proton current but do not allow other species to pass through at appreciable rates may be used herein. Thereby, electrolysis of pure water can be achieved, with significant advantages in chemical simplicity and absence of undesirable by-products. The proton conducting membrane can be a sulfonated derivative of Teflon, such as Nafion, Aquivion, and similar products. These cells are commonly referred to as proton exchange membrane water electrolyzers (PEMWE).

For example, conventional PEMWE industrial electrolyzers in the "Membrel" process for oxygen/hydrogen production have cell voltages, and when cell voltages are increased and ozone-selective catalysts are used, membranes and Due to the degradation of the electrodes, the achievable service life is considerably shortened, especially due to some free radical-mediated reactions that effectively attack the membrane polymer.

The selective formation of ozone instead of oxygen has hydrogen as the waste product, and the goal of the present disclosure is not necessarily the lowest energy cost, but rather the combination of high dissolved ozone concentration and long service life of the bath. To achieve this goal, boron-doped diamond electrodes can be used to take advantage of this material's preferential ratio of ozone formation to oxygen formation. However, BDD as a material is essentially equivalent to diamond in terms of mechanical properties and must be fabricated by direct synthesis of a doped diamond layer on a suitable substrate to form a layer of controlled conductivity. Therefore, we present some practical challenges. Therefore, BDD electrodes may be relatively expensive and fragile. Although platinum can be used in some situations, platinum oxide can contaminate the membrane over time.

In one embodiment, the bath 104 is a pair of perforated silicon plates with a thin boron-doped diamond coating, such as from less than 100 nm up to 15 μm, typically 5 μm. , including a perforated silicon plate, which can be coated >25 μm, with a layer of proton-conducting membrane 212 between the silicon plates, and channels for water and emitted gas to pass through the perforated surface. This configuration provides the necessary three-phase boundary area at the edges of all holes in the plate. Therefore, the BDD electrode can be a perforated silicon plate with a boron-doped diamond coating.

System Level Polarity Switching One embodiment of the system described herein has gas separators 110b, 110a for the cathode and anode, respectively, identical in size, structure, volume, and their ability to separate gas bubbles from the fluid. , includes a design in which both the cathode recirculation path 118 and the anode recirculation path 116 of the ozone electrolyzer 104 are symmetrical. Additionally, both sides may require dissolved ozone sensors, such as two UV sensors 108 or one sensor capable of measuring two separate fluid paths, or either side of the system may require a sensor to pass through the sensor. A single sensor with a series of reversible isolation valves provides the system with the ability to monitor ozone gas in either the cathode recirculation path 118 or the anode recirculation path 116. The ability to measure ozone gas in both paths simultaneously or alternating measurements from one side of the system to the other can provide additional self-diagnostics. By monitoring both sides, a decision can be made to maintain the anode as an anode, or if the ozone level is acceptably low (below 0.2 ppm or undetectable), the system can reverse polarity. can. The polarity to the bath can be changed via an H-bridge to provide exhaust flow from either side of the system producing ozone. Another benefit of monitoring ozone levels at both the anode and cathode is to monitor gas crossover. Ozone within the cathode recirculation path 118 may indicate early signs of tank membrane perforation or loss of fluid and/or gas seal. This type of self-diagnosis can both help alleviate safety concerns as well as alert end users before loss of functionality or performance.

The need to switch system polarity may arise from the need to maintain two important system characteristics related to fluid level in the catholyte and reliability. In operation, water molecules are drawn through membrane 212 by electroosmosis. Over time, the catholyte separator may increase its fluid level. Without a drain or reason to drain the cathode side of the system, the cathode separator will fill up and eventually need to be drained. By daily switching the polarity of the entire system, small increases in fluid levels from the day of use are easily managed. Reliability requirements for polarity switching arise from the long-term performance goals of the electrolyzer and the need to maintain the cleanliness of the water in the catholyte without requiring special start-up or shutdown process steps. Membrane degradation resulting from the interaction of ozone with other oxidizing species (HO, H2O2, H3O...) can be distributed on both sides of the bath to extend the lifetime of each membrane.
Additionally, the catholyte can be changed daily and each side of the system can be ozonated to prevent stagnant water and eliminate the possibility of microbial contamination.

Conventional optical methods exist for detecting levels of dissolved ozone in water using ozone's ultraviolet absorbance. However, changes in the mechanism and optical path (ie, debris, aging of the UV source) may require offset correction. By changing the polarity daily to the system, any sensor offset can be zeroed out using the previous day's cathode water, water containing dissolved hydrogen, and corrections can be made without variable concentrations of absorbing components in the water. can.

Turning now to FIG. 2, an exploded view of a manifold compatible ozone electrolytic cell 104 (manifold compatible EO cell) is shown. The assembly includes an interface seal 202 that creates a fluid seal between the EO reservoir 104 and the surface of the fluid manifold. Top plate 204 and bottom plate 216 are combined to provide a rigid housing and form an internal cavity surrounding internal components (ie, contact plates, electrodes, membranes, etc.). The top and bottom plates direct water flow into and out of the electrode pair 210. Prevents the catholyte (cathode recirculation path 118) side of the ozone electrolyzer 104 from mixing or intersecting water and gas with the anolyte side (anode recirculation path 116) of the EO cell, and vice versa. By assembling all the components in such a way, a separate waterway is formed. The top and bottom plates also define the cross-sectional area of the fluid path that creates the flow rate necessary to remove the bubbles from the electrode and membrane surfaces and transport them out of the EO bath as they form. The tolerance compressor 206 both provides an internal seal forming the upper fluid cavity and seals the electrical contact areas, but also compresses and varies the tolerance stack-up from the internal assembly by compressing and varying its total thickness. to manage. Tolerance compressor 206 also generates and maintains a clamping force on the electrode assembly: two Ti contact plates 208, two electrodes 210, and one or more, preferably two or more, proton exchange membranes 212. Two membranes may improve longevity and prevent mechanical shear stress from damaging the membrane. Additionally, the BDD electrode may grip the two aforementioned electrodes, although the two membranes may tend to slide. An inner bottom gasket/seal 214 seals the bottom plate to form the opposing fluid cavity. The inner bottom gasket/seal 214 also collects the two electrodes 210 and the two proton exchange membranes 212 into its inner rectangular opening, orthogonal to the upper and lower contact plates 208. Tolerance compressor 206 and/or inner bottom gasket/seal 214 seals the surface of contact plate 208 to create a dry electrical contact area on small tab 220 or the electrical contact area of the contact plate. This electrical contact area can be accessed through the top plate by spring-loaded electrical contacts (eg, pogo pins) so that the contact plate can supply current to the electrodes during electrolysis. Both the tolerance compressor 206 and the inner bottom gasket/seal 214 create a seal with the top and bottom plates to prevent water and gas from escaping through the seams within the assembly. Assembly screws 218 secure the top and bottom plates and compress the tolerance compressor 206 and inner bottom gasket/seal 214 to force the electrode tightly onto the proton exchange membrane and secure the top and bottom plates together. generate the necessary force.

Turning now to FIG. 3, images of the internal components of a single electrode-manifold compatible electrolytic cell are shown in different orientations.

FIG. 4 shows an exemplary photograph of the inner surface of a boron-doped diamond-coated electrode and proton exchange membrane after 77 hours of an exemplary test operation that produced 6 ppm ozone using closed-loop control (approximately 12 V and 0.3 A). show. On the ozone side, "white damage" (created by visible light scattering, which may be due to blister formation in the membrane) is seen. Blistering can create regions of low conductivity in the membrane. By replacing the cell with the same electrode and membrane to test whether the seal was maintained and running the test for 18.6 hours, it was found that the cell showed no crossover.

FIG. 5 is an image of the proton exchange membrane 212 after several hundred hours of operation demonstrating how the electrodes move closer together as the proton exchange membrane thins under the constant degradation that occurs during electrolysis. . This thinning is managed by a tolerance compressor that maintains sufficient clamping force on the electrode pair during the life of the EO cell. Tolerancing the material stackup to either maximum or minimum material requirements is another important aspect of tolerance compressors. Each assembly can achieve a minimum normal force (in the y-direction of FIG. 2) to produce an acceptable EO cell impedance. If the clamping force is too low, only a portion of the electrode surface is used, reducing the ozone production ability of the EO bath. Too high a clamping force caused by maximum material conditions can result in overcompression of the seal resulting in electrode damage, membrane damage, or loss of fluid path. Tolerance compressor 206 addresses all of these concerns. The material may be ozone inert and provide sufficient compression over a wide compression range, such as 2-10%, or 2-30%, or 10-50%, or 2-50% of its thickness. obtain. This high level of compression and material compatibility can be achieved with materials such as closed cell ethylene propylene diene monomer (EPDM) foam.

Figure 6 highlights the location and thickness of the tolerance compressor in cross-sectional view 602 and shows how the tolerance compressor fits into the internal stack-up of components after the top and bottom plates reduce the thickness of the tolerance compressor during the assembly process. We will also demonstrate how to apply force to Compressible layer 604 (or tolerance compressor 206) accounts for the thinning of proton exchange membrane 212 such that at least the compressive force on electrode-membrane-electrode stack 606 is maintained. That is, the proton exchange membrane 212 may experience thinning from mechanical seating on the surface of the boron-doped diamond coating and loss of membrane material due to membrane degradation. Membrane 212 may also swell upon initial hydration from a dry state. Accordingly, tolerance compressor 206 compresses or expands to accommodate contraction or swelling. Additionally, tolerancing the material stack-up to either maximum or minimum material requirements is another important aspect of tolerance compressors. Each assembly can achieve a minimum normal force to produce an acceptable EO cell impedance. If the tightening force is too low, only a portion of the electrode surface is used, which may reduce the ozone generation ability of the EO tank. Too high clamping forces caused by the maximum material condition "MMC" (all parts at their maximum tolerances and the assembly is tight) may result in overcompression on the seal resulting in electrode damage, membrane damage, or loss of fluid path. can bring about Tolerance compressor 206 addresses all of these concerns.

FIG. 7 shows an embodiment of a scaler with an aqueous ozone generator. A fluid manifold may be envisaged to maintain the size of the scaler. The manifold allows the scaler to produce an aqueous ozone solution without dramatically changing its footprint or size. Adds a fluid system that allows you to empty water from consumables. A pressurized system (eg, 17-25 psi, typically 22 psi) is created. Said water is converted to ozonated water by electrolysis via a closed loop control circuit with a UV absorbance sensor to maintain the ozone concentration, and this water is delivered to the ultrasonic handpiece 106.

FIG. 8 shows a housing perspective view demonstrating the manifold assembly 804 integrated into the ultrasonic scaler housing.

FIG. 9 provides a top perspective view 902 and a bottom perspective view 904 of the manifold assembly. Manifold assembly 804 may include five core submodules. The manifold-compatible ozone electrolyzer 104, in an exemplary embodiment, includes a coplanar seal (e.g., xz of the top plate, as shown in FIG. A planarly disposed interfacial seal 202) may be provided. Ozone electrolyzer 104 may be designed for high volume production equipment. The ozone electrolyzer 104 is characterized by a simplified electrode, contact scheme and seal arrangement. The interface seal 202 and low-profile design (relatively short height in the y direction in FIG. 2 compared to conventional designs) make the ozone electrolyzer 104 compact and compatible with existing industrial ultrasonic scaler system designs and manifolds. directly support the integration of For example, if the assembly is welded, the assembly may be 4-6 mm thick instead of, for example, 12-25 mm thick to accommodate threads and fittings and other assembly hardware. In-line catalyst 906 (O3 removal) may destroy ozone gas by converting it to oxygen (O2) so that excess ozone gas can be released from the manifold. In-line catalyst O3 removal may be designed as a body integrated into the manifold assembly 804. The design may provide access from the underside to aid serviceability, as the catalyst used for ozone destruction may be a serviceable element. The UV sensor 108 can quantify ozone concentration using the absorbance of ultraviolet light by ozone. The UV sensor 108 may have a simplified tolerance stack, thermal stability, and reduced size compared to conventional UV sensors to aid in integration into the ozone aqueous ultrasonic scaler system 100, and its The optical path may be shared by both the anode and cathode paths to reduce the number of fluid valves needed to support intermittent (eg, daily) polarity switching. Every other day, the catholyte side is switched to the anolyte side and the UV sensor 108 may need to monitor water recirculation on the anolyte side of the manifold. Magnetic float level detection 908 may be designed to monitor fluid level within the gas separator. Gas separators 110a, 110b may maintain fluid levels during operation, and thus the float provides a stable indicator of water level that can be tracked via an array of Hall effect sensors. The sensitivity of magnetic float level detection provides sufficient fidelity for real-time flow monitoring, providing the system and user with information on the amount of water being dispensed per unit time (eg, 20 ml/min). Magnetic float level detection 908 may be configured to be mechanically independent to eliminate dependence on optical or capacitive sensors that may see sloshing, droplets, or bubbles in level detection. Pressure relief valves 910 (PRVs) of reduced size compared to conventional sizes may provide stable, low hysteresis system pressure regulation (i.e., 15-30 psi, more typically 19-21 psi, 19 .5 to 22.5 psi). Accordingly, the "reduced" size of PRV 910 is intended to support a small footprint of ozone aqueous ultrasonic scaler system 100.

FIG. 10 provides a top perspective view 902 of an exemplary manifold assembly 804 in which electrical connections for the ozone electrolyzer 104 may be installed after the ozone electrolyzer 104 is attached to the manifold, secured, and sealed.

FIG. 11 shows a bottom perspective view 904 of the exemplary manifold assembly 804. This figure shows a thin ozone electrolyzer 104 and an aqueous ozone solution having an interface coplanar with the manifold surface 1102 (in the vertical/horizontal direction of the assembly 804, i.e., in the xz plane as shown in FIG. 11). 8 shows an electrolytic cell housing (top and bottom plates) configured to be coupled to a manifold assembly 804 of an ultrasonic scaler system 100.

FIG. 12 shows a bottom perspective view 904 of the example manifold assembly 804 showing the example ozone electrolyzer 104 and the location of the tank in the manifold assembly 804. In the figure, the detail of the tank interface seal 202 is shown as an O-ring interface. However, a single gasket may be made to replace the four O-rings and provide an air-tight and liquid-tight seal between the ozone electrolyzer 104 and the manifold surface.

FIG. 13 shows a cross-sectional view 1304 of the manifold assembly 804 showing the electrical connections of the ozone electrolyzer.

A spring-loaded pogo pin 1302 extends down through the manifold to reach the reservoir 104 and electrically engage the contact plate (Ti contact plate 208). The pogo pins 1302 can generate the normal force necessary to create reliable electrical contact with a contact plate (e.g., a titanium contact plate) while the pogo pins on the opposite side of the manifold with the EO tank contact plate. Variations in dimensional tolerances are also accommodated as the pogo pin collapses during compression of the pogo pin with the support structure. In an exemplary embodiment, the pogo pins terminate to a printed circuit board that is connected to the main control board either directly or through a small board-to-board cable harness. The pogo pin supplies the current that drives the electrolytic reaction within the EO cell. Wires may be soldered to pogo pins 1302 at solder locations 1306, and pogo pins 1302 may contact Ti contact plate 208 at top contacts 1308 and bottom contacts 1310.

FIG. 14 shows an alternative embodiment in which the ozone electrolyzer 104 is constructed using two pairs of electrodes. Ozone electrolyzer 104 may be comprised of one, two, or more electrode pairs. The advantage of having two pairs of BDD electrodes 210, each independently controlled such that each electrode has a contact plate and a separate electrical connection, is that fluid flows through both pairs of electrodes, so that , the electrode pairs are plumbed in series by channels within the manifold. Alternatively, a reservoir design can be developed that has a single fluid inlet and a single fluid outlet such that the reservoir provides fluidic interconnection between the two pairs of electrodes. However, electrically they have a separate constant current drive circuit. This allows the primary controller to turn on one or both pairs. Both electrode pairs can be used to rapidly increase ozone concentration after the system is off or in extended sleep mode (overnight, between patients, or during lunch). The current to each pair can also be controlled independently such that each pair can receive a current range from no current to 150 mA, or 100-1000 mA (typically 250 mA/bath). Each pair operates independently such that one pair of electrodes can be off while the other is used to maintain the ozone concentration (0.2-22 ppm, typically 6 ppm) I can do it.

FIG. 15 shows a cross-sectional area of the ozone electrolyzer 104 showing the bubble removal gap 1502 above the electrode. The dimensions of the fluid path around the electrode are shown, and the bubble removal gap 1502 is determined by the overall system requirements: recirculation flow rate (volume per unit time), ozone production rate, exit flow rate from the system, and ozone set point. is connected with. A fluid path is formed between the BDD electrode 210 and the bottom plate 216 by the thickness and internal profile of the Ti contact plate 208. This fluid path controls the speed of water moving over the surface of the BDD electrode 210. Too slow fluid flow (eg, large gap, low flow rate) can result in reduced efficiency of the ozone electrolyzer 104 due to air bubble entrapment and inability of fresh water to reach the three-phase boundary. A similar fluid path is formed on the opposite side of the electrode pair, but a tolerance compressor forms this fluid path. In alternative designs, additional membranes or outer layers may be included in the tolerance compressor to provide a hard, uniform wall comparable to the bottom housing surface. Maintaining a completely symmetrical design directly supports polarity switching, so that both sides of the electrode pair can be cathodes or anodes.

FIG. 16 shows the footprint of an ozone electrolyzer 104 with symmetrical fluidic and electrical connections. A symmetrical footprint may eliminate the need to orient the reservoir with the manifold. This can directly aid the ease of manufacture and maintainability of the assembly. Because the bath is completely symmetrical both electrically and fluidically, there may be no initial orientation requirements. The flow path to and exit from the reservoir as shown may be consistent in geometry, and the electrical polarity of each electrode pair may be reversed periodically (e.g., daily) to ensure reliability of the reservoir. It may be intended to improve and flush the catholyte every other day. A fully symmetrical reservoir design may eliminate the need for mechanical keying features and the possibility of damaging coplanar interfaces by securing the reservoir in the wrong orientation. Assuming that the bath of FIG. 16 has two sides, side A and side B, the footprint is electrical contact 1602 on side A, outlet 1604 on side A, outlet 1606 on side B, electrical contact 1608 on side B. , a side B inlet 1610, and a side A inlet 1612.

FIG. 17 depicts an electrode 1702 with exemplary dimensions having a tab 1704 that provides direct electrical contact, illustrating a configuration that may eliminate the need for a separate contact plate. The contact plate is therefore integrated with the electrode. The electrodes can be made from titanium sheets and the profiles can be stamped, laser cut, or etched. Alternatively, the electrodes may be formed by metal injection molding or powder metal sintering. The titanium substrate can then be coated with boron-doped diamond using vapor deposition. The coating can be conductive and cover the entire substrate, or alternatively, the tabs can be masked before coating to provide a titanium surface for electrical connection. This tabbed electrode eliminates the need for contact plates, reduces part count and simplifies assembly steps.

Having described an apparatus, reference is now made to FIG. 18, which illustrates a block diagram of a computer system 1800 that may be used in accordance with at least some of the example embodiments herein. Although various embodiments may be described herein with respect to this exemplary computer system 1800, after reading this description how to implement the present disclosure using other computer systems and/or architectures. may be apparent to those skilled in the art.

In one exemplary embodiment herein, at least some components of the ozone aqueous ultrasonic scaler system 100 in which the ozone electrolyzer 104 is located may form the computer system 1800 of FIG. may be included in computer system 1800. Computer system 1800 includes at least one computer processor 1806. Computer processor 1806 may include, for example, a central processing unit (CPU), multiple processing units, an application specific integrated circuit (“ASIC”), a field programmable gate array (“FPGA”), or the like. Computer processor 1806 may be connected to communications infrastructure 1802 (eg, a communications bus, crossover bar device, network). In exemplary embodiments herein, computer processor 1806 includes a CPU that controls the timing of ozone electrolyzer 106 and the ozone formation process.

Display interface 1808 (or other interface) transfers text, video graphics, and other data from communication infrastructure 1802 (or from a frame buffer (not shown)) for display on display unit 1814. For example, display interface 1808 may include a video card with a graphics processing unit or may provide an interface for an operator to control the device.

Computer system 1800 also includes an input unit 1810 that may be used in conjunction with display unit 1814 by an operator of computer system 1800 to transmit information to computer processor 1806, such as information controlling operation of ozone electrolyzer 104. . Input unit 1810 may include, for example, a touch screen monitor. In one example, display unit 1814, input unit 1810, and computer processor 1806 may collectively form a user interface.

One or more steps of providing ozonated water to an ultrasonic scaler handpiece may be stored in a non-transitory storage device in the form of computer readable program instructions. To perform an action, computer processor 1806 loads appropriate instructions stored in storage into memory and then executes the loaded instructions.

Computer system 1800 further comprises main memory 1804, which may be random access memory (“RAM”), and may also include secondary memory 1818. Secondary memory 1818 may include, for example, a hard disk drive 1820 and/or a removable storage drive 1822 (eg, a floppy disk drive, a magnetic tape drive, an optical disk drive, a flash memory drive, etc.). Removable storage drive 1822 reads from and/or writes to removable storage unit 1826 in a well-known manner. Removable storage unit 1826 can be, for example, a floppy disk, magnetic tape, optical disk, flash memory device, etc., which can be written to and read by removable storage drive 1822. Removable storage unit 1826 may include non-transitory computer-readable storage media for storing computer-executable software instructions and/or data.

In further exemplary embodiments, secondary memory 1818 may include other computer-readable media that store computer-executable programs or other instructions that are loaded into computer system 1800. Such devices include a removable storage unit 1828 and an interface 1824 (e.g., a program cartridge and cartridge interface) and a removable memory chip (e.g., erasable programmable read-only memory ("EPROM") or programmable read-only memory). only memory (“PROM”) and associated memory sockets and other removable storage units 1828 and interfaces that allow software and data to be transferred from removable storage unit 1828 to other parts of computer system 1800 1824.

Computer system 1800 may also include a communications interface 1812 that enables the transfer of software and data between computer system 1800 and external devices. Such interfaces include modems, network interfaces (e.g., Ethernet cards, or IEEE 802.11 wireless LAN interfaces), communication ports (e.g., Universal Serial Bus ("USB") ports or FireWire ports), PC memory Card International Association (“PCMCIA”) interface, Bluetooth®, and the like. Software and data transferred through communication interface 1812 are in the form of signals that may be electronic, electromagnetic, optical, or another type of signal that may be capable of being transmitted and/or received by communication interface 1812. could be. Signals may be provided to communication interface 1812 via communication path 1816 (eg, channel). Communication path 1816 carries signals and may be implemented using wire or cable, fiber optics, telephone lines, cellular links, radio frequency (“RF”) links, and the like. Communication interface 1812 may be used to transfer software or data or other information between computer system 1800 and a remote server or cloud-based storage (not shown).

One or more computer programs or computer control logic may be stored in main memory 1804 and/or secondary memory 1818. Computer programs may further be received via communications interface 1812. The computer program includes computer-executable instructions that, when executed by computer processor 1806, cause computer system 1800 to perform the methods described below. Accordingly, the computer program can control computer system 1800 and other components of ozone aqueous ultrasonic scaler system 100.

In another embodiment, the software is stored on a non-transitory computer-readable storage medium and uses removable storage drive 1822, hard disk drive 1820, and/or communication interface 1812 to store main memory 1804 and/or The data may then be loaded into memory 1818. Control logic (software), when executed by computer processor 1806, causes computer system 1800, and more generally the apparatus, to perform some or all of the methods described herein.

Finally, in another exemplary embodiment, hardware components such as ASICs, FPGAs, etc. may be used to perform the functions described herein. Implementation of such hardware components to perform the functions described herein will be apparent to one or more of ordinary skill in the art from this description.

Claims (25)

An ozone electrolyzer,
interface seal,
an upper plate;
a housing including a bottom plate;
a pair of contact plates;
a tolerance compressor for compressing an electrode-membrane-electrode stack comprising a pair of electrodes and at least one proton exchange membrane;
The electrode-membrane-electrode stack is disposed between the pair of contact plates, and the tolerance compressor is configured to thin the proton exchange membrane to maintain at least a compressive force on the electrode-membrane-electrode stack. configured to change the dimensions of the tolerance compressor in response;
Ozone electrolyzer. 2. The ozone electrolyzer of claim 1, wherein the electrolyzer housing is configured to be coupled to a manifold assembly of an aqueous ozone ultrasonic scaler system such that the electrolyzer housing has a coplanar interface with the manifold surface. The ozone electrolyzer according to claim 1, wherein the pair of contact plates are titanium (Ti) contact plates. The ozone electrolyzer according to claim 1, wherein the pair of electrodes are boron-doped diamond (BDD) electrodes. The ozone electrolyzer according to claim 1, wherein the electrodes of the pair of electrodes are perforated silicon plates with a boron-doped diamond coating. The ozone electrolyzer according to claim 5, wherein the boron-doped diamond coating has a thickness of 100 nm to 15 μm. The pair of electrodes and the proton exchange membrane form an electrode-membrane-electrode stack, and the tolerance compressor has a 2. The ozone electrolyzer of claim 1, wherein the ozone electrolyzer provides compression for. 2. The ozone electrolyzer of claim 1, wherein the tolerance compressor is ozone inert. The ozone electrolytic cell of claim 1, wherein the tolerance compressor is made from a closed cell ethylene propylene diene monomer (EPDM) foam material. The ozone electrolyzer of claim 1, wherein the path for water flow is based on the contact plate thickness and internal profile of the pair of contact plates. The ozone electrolytic cell according to claim 1, wherein the ozone electrolytic cell includes two or more pairs of electrodes. 5. The electrical contact areas of the contact plates of the pair of contact plates are accessed through the top plate by spring-loaded electrical contacts such that the contact plates supply current to the electrodes of the pair of electrodes. 1. The ozone electrolytic cell according to 1. 2. The ozone electrolyzer of claim 1, wherein the contact plate and the electrode are integrated to form an electrode unit that provides direct electrical contact for a spring-loaded electrical contact. Ozone electrolysis according to claim 1, wherein the bath is configured to control the velocity of water flowing through a bubble-forming region along a three-phase boundary (TPB) formed by an electrode-water-membrane interface. Tank. The ozone electrolyzer further includes an inner bottom gasket, the inner bottom gasket and the tolerance compressor sealing one or more surfaces of the pair of contact plates to seal one or more dry electrical contact areas to the one or more dry electrical contact areas. The ozone electrolyzer according to claim 12, produced on the tabs of a pair of contact plates. The ozone electrolytic cell of claim 1, wherein the electrode-membrane-electrode stack includes one or more electrode pairs in the same cell. 18. The ozone electrolyzer of claim 17, wherein the one or more pairs are each independently controlled. a water supply source for delivering water to the ozone electrolyzer;
a gas separator disposed in a recirculation loop of the fluid path that also includes the electrolytic cell;
An apparatus comprising the ozone electrolyzer,
The ozone electrolyzer is
interface seal,
an upper plate;
a housing including a bottom plate;
a pair of contact plates;
and an internal compartment comprising at least a tolerance compressor for compressing an electrode-membrane-electrode stack comprising a pair of electrodes and at least one proton exchange membrane;
The electrode-membrane-electrode stack is disposed between the pair of contact plates, and the tolerance compressor is configured to thin the proton exchange membrane to maintain at least a compressive force on the electrode-membrane-electrode stack. configured to change the dimensions of the tolerance compressor in response;
Device. 20. The apparatus of claim 19, wherein the pair of contact plates are titanium (Ti) contact plates. 20. The apparatus of claim 19, wherein the pair of electrodes are boron doped diamond (BDD) electrodes. 20. The apparatus of claim 19, wherein the electrode-membrane-electrode stack includes one or more electrode pairs in the same bath. 23. The apparatus of claim 22, wherein the one or more pairs are each independently controlled. a processor configured to control operation of the ozone electrolyzer;
A computer system comprising the ozone electrolyzer,
The ozone electrolyzer is
interface seal,
an upper plate;
a housing including a bottom plate;
a pair of contact plates;
and an internal compartment comprising at least a tolerance compressor for compressing an electrode-membrane-electrode stack comprising a pair of electrodes and at least one proton exchange membrane;
The electrode-membrane-electrode stack is disposed between the pair of contact plates, and the tolerance compressor is configured to thin the proton exchange membrane to maintain at least a compressive force on the electrode-membrane-electrode stack. configured to change the dimensions of the tolerance compressor in response;
computer system. 25. The computer system of claim 24, wherein the pair of contact plates are titanium (Ti) contact plates. 25. The computer system of claim 24, wherein the pair of electrodes are boron doped diamond (BDD) electrodes.

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