Methods and systems for negative ion-based contaminant reduction - Patents.com

Abstract

A purification system and method of using such a system are provided for purifying various environments, such as indoor air, outdoor air, vehicle exhaust, and industrial exhaust. The purification system includes an ionization purification device having a substrate and an active coating. The active coating includes pyroelectric and / or piezoelectric materials. In operation, an inlet stream is directed toward the active coating while controlling the average pressure exerted on the active coating. This contact between the inlet stream and the active coating generates negative ions from components of the inlet stream through changes in temperature and pressure / force / vibration, etc. The negative ions then interact with contaminants and convert them into safe, purified substances in the outlet stream. Unlike the contaminants in the inlet stream, the purified substances are harmless and / or can be easily removed from the outlet stream, for example, by filtering and / or other separation techniques.

Description

[Technical field]

[0001] This patent application claims priority to pending U.S. patent application Ser. No. 17 / 127,273, entitled "METHODS AND SYSTEMS FOR NEGATIVE ION-BASED POLLUTION REDUCTION" and filed on December 18, 2020 by Mark DiCarlo, which is incorporated herein by reference in its entirety for all purposes. [Background technology]

[0002] Air pollution has become a major problem worldwide due to various health problems. For example, an estimated 7 million people die from air pollution every year. At the same time, air pollution appears to be the major form of pollution in the world, with more pollutants being emitted into the air than into water and land combined. For the purposes of this disclosure, air pollution is defined as the environmental contamination of air by any agent that changes the natural properties of the air.

[0003] Various methods and systems have been proposed to mitigate air pollution, and more specifically, to remove pollutants from the ambient air and from gas streams that are emitted into the air (e.g., vehicle exhaust systems, chimneys). For example, ionizers have been proposed for pollution reduction. In a typical ionizer, a voltage is applied between electrodes, causing an electrical discharge through the environment between the electrodes. However, such methods typically result in other environmental concerns, such as the generation of ozone. Additionally, these methods tend to be inefficient, require significant power or specialized construction, and do not rely on natural methods of air purification. Summary of the Invention

[0004] A purification system and method of using such a system for purifying various environments, such as indoor air, outdoor air, vehicle exhaust, industrial exhaust, etc., is provided via a purification system comprising an ionization purification device having a substrate and an active coating. The active coating comprises a pyroelectric material and / or a piezoelectric material. In operation, an inlet stream is directed towards the active coating while controlling the average pressure exerted on the active coating. This contact between the inlet stream and the active coating generates negative ions from components of the inlet stream through changes in temperature and pressure / force / vibration, etc. The negative ions then interact with contaminants and convert them into safe, purified substances in the outlet stream. Unlike the contaminants in the inlet stream, the purified substances are harmless and / or can be easily removed from the outlet stream, for example, by filtering and / or other separation techniques.

[0005] In some examples, a method is provided for purifying an inlet stream using a purification system to form an outlet stream. The method includes flowing the inlet stream into an ionization purification device of the purification system. The inlet stream includes one or more contaminants. The ionization purification device includes a substrate and an active coating disposed on the substrate, the active coating including a material that is pyroelectric and / or piezoelectric. The method also includes directing the inlet stream toward the active coating while controlling an average pressure that the inlet stream exerts on the active coating. Upon contact with the active coating, the inlet stream generates negative ions from one or more components of the inlet stream. The negative ions interact with the one or more contaminants to form a purified substance in the outlet stream. The method further includes directing an outlet stream including the purified substance from the ionization purification device.

[0006] In some examples, the material includes one of aluminum nitride, aluminum phosphate, barium titanate, bismuth titanate, gallium nitride, gallium phosphate, lithium niobate, lithium tantalate, lithium tetraborate, quartz, tourmaline, triglycine sulfate, and zinc oxide. In more specific examples, the material includes at least two different ones of aluminum nitride, aluminum phosphate, barium titanate, bismuth titanate, gallium nitride, gallium phosphate, lithium niobate, lithium tantalate, lithium tetraborate, quartz, tourmaline, triglycine sulfate, and zinc oxide.

[0007] In some examples, directing the inlet stream toward the active coating is performed while controlling a temperature of the inlet stream prior to contacting the active coating. More specifically, controlling a temperature of the inlet stream prior to contacting the active coating includes passing the inlet stream through a temperature control device prior to contacting the active coating. In some examples, the temperature control device includes at least one of a heater and an air conditioner / chiller.

[0008] In some examples, directing the inlet stream to the active coating is performed while controlling the temperature of the active coating. In more specific examples, controlling the temperature of the active coating is performed using a temperature control device thermally coupled to the active coating. For example, controlling the temperature of the active coating includes controlling the flow rate of the inlet stream into the ionization purification device.

[0009] In some examples, directing the inlet stream toward the active coating is performed while controlling a contact angle between the inlet stream and the active coating. In a more specific example, controlling the contact angle between the inlet stream and the active coating includes directing the inlet stream through a flow director.

[0010] In some examples, the active coating is encapsulated within an ionization purification device that blocks ambient light when the inlet stream generates negative ions from one or more components of the inlet stream, and in more specific examples, the active coating is not exposed to sunlight when generating negative ions.

[0011] In some examples, the substrate supporting the active coating is selected from the group consisting of blower blades, filter surfaces, housing surfaces, ionizer electrodes, chimney interior walls, scrubber components, and electrostatic precipitator components. In the same or other examples, the active coating is a continuous coating and isolates the substrate beneath the active coating from the environment. Alternatively, the active coating includes a plurality of discontinuous particles positioned on the surface of the substrate. In some examples, the substrate is porous. The active coating includes a plurality of discontinuous particles disposed within the substrate and spaced from the surface of the substrate. In some examples, the substrate includes pores such that the active coating forms a surface of the pores. In some examples, the active coating includes active coating pores such that the inlet stream is directed into the active coating pores.

[0012] In some examples, directing the inlet stream to the active coating is performed through a set of concentric structures, at least one of which is operable as a substrate for the active coating. For example, at least another of the concentric structures includes a set of openings operable as a flow director to direct the inlet stream to the active coating. In some examples, at least one structure of the set of concentric structures is an air filter. In some examples, the set of concentric structures is part of an automobile exhaust system.

[0013] In some examples, directing the inlet stream toward the active coating is performed using a blower operable as a flow rate control device. Controlling the average pressure that the inlet stream exerts on the active coating includes controlling a rotational speed of the blower.

[0014] In some instances, the input stream fed into the ionizing purification device comprises water.

[0015] In some examples, the method further includes separating the purified material from the effluent stream.

[0016] Also provided is a purification system for purifying an inlet stream. In some examples, the purification system comprises an ionization purification apparatus including a substrate and an active coating. The active coating is disposed on the substrate and includes a material that is pyroelectric and / or piezoelectric. The purification system is configured to direct the inlet stream toward the active coating while controlling the average pressure that the inlet stream exerts on the active coating.

[0017] In some examples, the purification system further comprises a temperature control device configured to control a temperature of the influent stream before the influent stream contacts the active coating, for example, the temperature control device comprises at least one of a heater and an air conditioner / chiller.

[0018] In some examples, the purification system further comprises a temperature controller thermally coupled to the active coating and configured to control a temperature of the active coating.

[0019] In some examples, the purification system includes a flow director configured to control the contact angle between the inlet stream and the active coating.

[0020] In some examples, the purification system further comprises a set of concentric structures, at least one of which is operable as a substrate for an active coating.

[0021] In some examples, the purification system further comprises a flow rate control device configured to control the average pressure that the inlet stream exerts on the active coating, including controlling a rotational speed of the blower.

[0022] These and other embodiments are further described below with reference to the figures. [Brief description of the drawings]

[0023] [Figure 1A] FIG. 1 is a schematic diagram illustrating purifying an inlet stream using negative ions generated when the inlet stream contacts an active coating, according to some examples. [Figure 1B] 1 is a plot showing negative ion generation rate as a function of pressure exerted on the active coating by the inlet stream. [Figure 1C] 1 is a plot showing negative ion generation rate as a function of temperature of an active coating surface while an inlet stream is directed at the active coating surface. [Figure 2A] FIG. 1 is a schematic block diagram of a purification system including an ionization purification device for purifying an inlet stream, according to some examples. [Figure 2B] 1 is a schematic cross-sectional view of an example purification system including an ionization purification device including pores having an active coating disposed within the pores. [Figure 2C] FIG. 2 is a schematic cross-sectional view of another example purification system in which an ionizing purification device forms an extended path through the purification system. [Figure 3A-3E] 1A-1D are schematic cross-sectional views of different examples of substrates and active coatings disposed on those substrates. [Figure 4A-4G] 1A-1D are schematic cross-sectional views of different example active coatings. [Diagram 5] 1 is a process flow diagram corresponding to a method of purifying an influent stream using a purification system, according to some examples. [Figures 6A-6D] 1 is a schematic cross-sectional view of different components and features of a vehicle exhaust system operable as a purification system and including an ionization purification device, according to some examples. [Figure 7A-7B] 2A-2C are two examples of industrial exhaust gas systems each equipped with one or more ionization purification devices. [Figure 8]1 is a schematic cross-sectional view of an ionizer having an integrated ionization purification device, according to some examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented concepts. The presented concepts may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail so as not to unnecessarily obscure the described concepts. While some concepts will be described in conjunction with specific embodiments, it will be understood that these embodiments are not intended to be limiting.

[0025] Introduction Described herein are methods and systems for purifying various environments using negative ions. Such purification methods may be referred to as ion-based purification and / or ion-based pollution reduction. These methods and systems can be used in many different applications, various examples of which are disclosed herein. These applications include indoor and outdoor applications, vehicle exhaust, and industrial applications. Specific examples include environmental purification in medical facilities (e.g., operating rooms / surgery suites), air purification in homes and office buildings (e.g., as a stand-alone system or integrated into heating-ventilation-air conditioning (HVAC) systems), exhaust gas treatment in factory chimneys, scrubbers, electrostatic precipitators, and other types of industrial equipment, carbon dioxide capture technologies / equipment, and many other similar applications. Additionally, these methods and systems can remove both man-made and natural pollutants, such as particulate matter, ozone, carbon monoxide, lead, hydrocarbons, volatile organic compounds, nitrogen oxides, carbon dioxide, sulfur dioxide, smog, volcanic gases, and many other similar pollutants.

[0026] Unlike conventional purification approaches, the methods and systems disclosed herein are environmentally friendly, efficient, and cost-effective. Specifically, these methods and systems utilize biomimicry-based solutions, which represent various methods of air pollutant purification found in nature. This novel purification approach is now introduced with reference to FIG. 1A. Specifically, FIG. 1A is a schematic diagram of an ionization purification device 110 during the processing of an inlet stream 180. The ionization purification device 110 can be part of various systems, such as various purification systems described below with reference to FIGS. 2A-2C, a vehicle exhaust system described below with reference to FIGS. 6A-6D, and an industrial exhaust control system described below with reference to FIGS. 7A and 7B.

[0027] 1A, the ionization purification device 110 comprises a substrate 120 and an active coating 130 disposed on the substrate 120. In some examples, the active coating 130 and the substrate 120 are the same component, i.e., the active coating 130 is a self-supporting structure. The active coating 130 includes a pyroelectric and / or piezoelectric material 131. Various examples of suitable pyroelectric and / or piezoelectric materials are provided below. It should be noted that all known pyroelectric materials are also piezoelectric.

[0028] The active coating 130, substrate 120, and other characteristics of these methods and systems (e.g., flow rate, temperature) are uniquely selected to generate negative ions 192 at the surface 134 of the active coating 130. More specifically, the active coating 130 generates an electrical change and negative ions when heated or cooled and / or pressure / stress / force is applied to the coating surface 134. The pressure is applied, for example, by an inlet stream 180 that includes one or more contaminants 186. Other components of the inlet stream 180 can include air 182, water 184 (e.g., in gaseous form), and ionized components 188. Any one of these components in the inlet stream 180 can generate negative ions 192 when subjected to the effect of heating or cooling and / or pressure / force on the coating surface 134.

[0029] It should be noted that both the temperature at the interface between the active coating 130 and the inlet stream 180 and the pressure applied by the inlet stream 180 to the coating surface 134 affect negative ion generation. FIG. 1B is a plot showing the rate of negative ion generation as a function of the pressure applied by the inlet stream 180 to the active coating 130. The rate of ion generation increases with pressure. Without being limited to a particular theory, it is believed that the mechanical energy provided by this pressure is converted to electrical energy by the piezoelectric effect provided by the active coating 130. For example, a pressure increase of approximately 100 Pascals increases the ejection rate of a particular type of tourmaline to 62,000 ions per cubic centimeter per second. It should be noted that this particular pressure is a function of the flow rate (e.g., flow rate) of the inlet stream 180, the density of the inlet stream 180, and the contact angle.

[0030] FIG. 1C is a plot showing the negative ion generation rate as a function of the temperature of the active coating surface 134 while an inflow stream 180 is directed at the surface. Without being limited to a particular theory, it is believed that a pyroelectric effect provided by the active coating 130 converts thermal energy into electrical energy. Thermal energy is provided by the inflow stream 180 (e.g., hot vehicle exhaust gases) and / or a separate heating element (e.g., temperature controller 150, described below with reference to FIGS. 2A-2C). Additionally, heat may be delivered to the active coating surface 134 by the inflow stream 180 and / or by the active coating 130 (e.g., a heater thermally coupled to the active coating 130). For example, at room temperature (e.g., about 20° C.), the emission rate of 80 nanometer grain tourmaline is about 1500 ions per cubic centimeter per second. When this particular variety of tourmaline is heated to 45° C., the emission rate is about 2,800 ions per cubic centimeter per second. At 135° C., the exhaust rate was approximately 24,000 ions per cubic centimeter per second. The temperature is controlled, for example, by the temperature of the inlet stream 180 and / or various temperature controllers (e.g., heaters and / or air conditioners / chillers) thermally coupled to the active coating 130.

[0031] Returning to FIG. 1A , the negative ions 192 interact with the contaminants 186 to form purified material 194, which is part of the effluent stream 190. Various components of the inlet stream 180 (e.g., air 182, ionized components 188) may also form part of the effluent stream 190 (e.g., without interacting with and / or participating in the formation of the negative ions 192). Various types of interactions between the negative ions 192 and the contaminants 186 range from (1) neutralizing positively charged contaminants, (2) further destabilizing unstable contaminants (e.g., ultimately causing decomposition), and / or (3) taking advantage of the electron affinity of certain molecules to absorb electrons. For example, chlorine (Cl2), which is highly toxic, poisonous, and corrosive, interacts with the negative ions due to its high affinity to absorb electrons. Upon reacting with the negative ions, chlorine gains electrons and changes to a chloride, such as sodium chloride (NaCl), which is more commonly referred to as salt. Unlike chlorine (Cl2), most chlorides are safe, non-toxic, and easily absorbed by plants. In another example, negative ions attract and attach to positively charged pollutants and dust. For example, almost all dust particles in the air are positively charged. When positively charged dust and negative ions attract each other, the negative ions stick together and form larger, heavier dust particles. These particles become too heavy to be suspended in the air and fall to the ground or are attracted to enclosed spaces or building walls. This pollutant binding process helps remove suspended pollutants from the air. It should be noted that years of scientific research and numerous studies have demonstrated that negative ions can eliminate air pollution. This technology eliminates air pollution by (1) neutralizing positively charged pollutants, (2) making unstable pollutants even more unstable (e.g., eventually causing them to break down), and / or (3) taking advantage of the electron affinity of certain molecules to absorb electrons.

[0032] In some examples, the methods and systems described herein also utilize the Lennard effect in the presence of water present. For the purposes of this disclosure, the Lennard effect is defined as a process of generating an electric charge by applying water to the surface of one or more pyroelectric and / or piezoelectric materials described above. In these examples, the water is provided as a fine spray, mist, or gas (e.g., steam) and is directed to the surface of the pyroelectric and / or piezoelectric materials using pressures and temperatures specific to each use case. It should be noted that this inlet stream also includes other components. Contaminants may be present among these other components and / or in the water. For example, a scrubber utilizes water to dissolve contaminants in the water. The scrubber may include an active coating, as further described below with reference to FIG. 7A.

[0033] Examples of purification systems FIG. 2A is a schematic block diagram of a purification system 100 according to some examples. FIGS. 2B and 2C are schematic diagrams of two examples of the purification system 100. The purification system 100 includes at least an ionization purification device 110, some examples of which have been described above with reference to FIG. 1A. Other components of the purification system 100 other than the ionization purification device 110 are optional. In some examples, the purification system 100 also includes a flow rate controller 140 for controlling the velocity of the inlet stream 180 as it is directed to the active coating 130, as shown, for example, in FIGS. 2A and 2B. As described above, the velocity of the inlet stream 180 determines the pressure on the active coating surface 134 and the generation of negative ions 192. Some examples of the flow rate controller 140 include, but are not limited to, a blower, a turbine, a valve, a flow restrictor, a flow diverter, and the like. Input to the flow rate controller 140 may be provided from various sensors, such as a flow meter, a contaminant sensor, and the like (e.g., sensor 172 in FIG. 2B). In some examples, the velocity of the inlet stream 180 is controlled external to the purification system 100, e.g., in a vehicle exhaust system, a chimney, a scrubber, an electrostatic precipitator, etc. It should be noted that some functions of the ionization purification device 110 may be provided by the flow rate control device 140. For example, the blower vanes or turbine blades may serve as the substrate 120 for the active coating 130. Additionally, in some examples, the pressure exerted by the inlet stream 180 on the active coating 130 is controlled by, for example, the movement of the active coating 130 on the surface of the blower vanes or turbine blades.

[0034] In some examples, the purification system 100 includes another optional component, a temperature controller 150. The temperature controller 150 is configured to control (e.g., vary) the temperature of the inlet stream 180 before the inlet stream 180 contacts the active coating 130, as shown, for example, in FIG. 2B. In the same or other examples, the temperature controller 150 is configured to directly control (e.g., vary) the temperature of the active coating 130. For example, the temperature controller 150 is thermally coupled to the active coating 130, as shown, for example, in FIG. 2C. Some examples of the temperature controller 150 include, but are not limited to, a heater (e.g., a resistive heater) and an air conditioner / chiller. Input to the temperature controller 150 may be provided from various sensors 172, such as thermocouples positioned on the flow path of the inlet stream 180, thermocouples oriented at the active coating surface 134, contaminant sensors 172, etc. In some examples, the temperature of the inlet stream 180 is controlled external to the purification system 100, for example, in a vehicle exhaust system, a chimney, a scrubber, an electrostatic precipitator, or the like.

[0035] In some examples, the purification system 100 includes yet another optional component, the flow director 160. The flow director 160 is configured to direct the inlet stream 180 toward the active coating surface 134, and in more specific examples, is configured to control the angle at which the inlet stream 180 is directed toward the active coating surface 134. Some examples of the flow director 160 include, but are not limited to, jets, nozzles, openings, and the like. In some examples, the flow director 160 can operate as a filter and is configured to capture at least a portion of the contaminants before they reach the active coating surface 134. Alternatively, the filter 170 is a separate component, as shown, for example, in FIGS. 2A and 2B. For example, the filter 170 may be positioned after the ionization purification device 110, for example, on the path of the outlet stream 190 to capture the remaining contaminants and / or purified material 194.

[0036] As described above, the ionization purification device 110 includes an active coating 130 disposed on a substrate 120. The substrate 120 and / or the active coating 130 may be specifically configured to increase the surface area of ​​the active coating 130 while minimizing the back pressure of the inlet stream 180. For example, the increased back pressure may be undesirable for various applications, such as vehicle exhaust systems. FIG. 3A shows a substrate 120 including a plurality of holes 122 with an active coating 130 disposed within the holes 122 and forming a surface of the holes 122. The inlet stream 180 flows into the holes 122 and contacts the active coating 130 to generate negative ions. These negative ions interact with pollutants in the inlet stream 180. FIG. 3B shows an enlarged view of one hole 122. In some examples of mufflers / tailpipes, the diameter of each hole 122 is between about 1 millimeter and 5 millimeters. In the same or other examples, the thickness of the active coating 130 is between 0.1 millimeter and 0.5 millimeters.

[0037] 3C and 3D, the holes 122 may have different orientations relative to the direction of the inlet stream 180. Specifically, FIG. 3C shows an example where the holes 122 are substantially parallel to the direction of the inlet stream 180. This example may be used, for example, to reduce back pressure through the ionization purification device 110. FIG. 3D shows an example where the holes 122 are positioned at an angle (e.g., 1°-15°) relative to the direction of the inlet stream 180. This example may be used, for example, to increase the pressure exerted by the inlet stream 180 on the active coating 130 and increase the negative ion generation rate, as described above with reference to FIG. 1B. In some examples, a flow rate control device 140 is positioned within the holes 122, for example, as shown diagrammatically in FIG. 3E. In these examples, the flow rate control device 140 may also be operable as a flow director 160, for example, for an even distribution of the inlet stream 180 within the holes 122.

[0038] Additionally, as discussed above, the active coating 130 includes a material 131 that is pyroelectric and / or piezoelectric. For purposes of this disclosure, a pyroelectric material is defined as a material that can generate an electrical potential when heated or cooled. A piezoelectric material is defined as a material that can generate an electrical charge in response to mechanical stress (e.g., compression). It should be noted that all known pyroelectric materials are also piezoelectric. Examples of material 131 include aluminum nitride (AlN), aluminum phosphate (AlPO4), barium titanate (BaTiO3), bismuth titanate (BiTiO4), and bismuth phosphate (BiPtO4). 12 TiO 20 , Bi4Ti3O 12 and / or Bi2Ti2O7), gallium nitride (GaN), gallium phosphate (GaPO4), lithium niobate (LiNbO3), lithium tantalate (LiTaO3), lithium tetraborate (Li2B4O7), quartz (SiO2), tourmaline (e.g., a crystalline borosilicate mineral complexed with elements such as aluminum, iron, magnesium, sodium, lithium, or potassium), triglycine sulfate ((NH2CH2COOH)3·H2SO4), and zinc oxide (ZnO). One or more of these materials (e.g., in specific combinations) may be used for a particular use case depending on a number of factors including, but not limited to, temperature, pressure, surface area, etc.

[0039] Various structural examples of the active coating 130 will now be described with reference to Figures 4A-4G. Figure 4A shows an example where the active coating 130 is continuous and isolates the substrate 120 placed under the active coating 130 from the environment. For example, particles of material 131 fuse together to form the active coating 130. Alternatively, the active coating 130 comprises a plurality of discontinuous particles positioned at least on the surface of the substrate 120, as for example shown diagrammatically in Figures 4B, 4C, and 4D. For example, Figure 4B shows an example where the discontinuous particles (forming the active coating 130) are supported on the surface of the substrate 120 using an adhesive 124 or any other bonding material. Figure 4C shows an example where the discontinuous particles (forming the active coating 130) are directly incorporated into the substrate 120 without the use of any intermediate material. Figure 4D is yet another example where the discontinuous particles (forming the active coating 130) are distributed throughout the volume of the substrate 120, and not just on the surface. This example may be used, for example, for a porous substrate that allows the inlet stream 180 to penetrate the substrate 120. For example, the substrate 120 may include concrete, or more specifically, porous concrete having the active coating 130 in the form of particles dispersed in the concrete.

[0040] In some examples, the substrate 120 is not a continuous, impermeable structure. For example, the substrate 120 may be in the form of a mesh (e.g., as shown in FIG. 4E), a foam, or other structure that allows the inlet stream 180 to flow through the substrate while contacting the active coating 130 positioned on the surface of the substrate 120. This type of substrate may be used in systems where the inlet stream has a large flow rate and back pressure is particularly undesirable.

[0041] In some examples, the active coating 130 includes active coating holes 132, as shown, for example, in FIG. 4F. In these examples, the inlet stream 180 is directed into the active coating holes 132. These examples may be used without the substrate 120, which is optional.

[0042] Overall, the particles of the active coating 130 can be in various forms, such as powder, stones, crushed stones, chips, pebbles, gravel, rods, etc. The particles can be identified as 1-D structures (labeled 134a and 134b in FIG. 4G), 2-D structures (labeled 134c in FIG. 4G), and 3-D structures (labeled 134d in FIG. 4G). For purposes of this disclosure, a 1-D structure has a ratio of one major dimension to each of the remaining two dimensions greater than 10. Some examples include, but are not limited to, nanotubes, nanowires, and fibers. A 2-dimensional structure has a ratio of each of the two major dimensions to each of the remaining dimensions greater than 10. Examples include, but are not limited to, flakes and sheets, and more specifically, thin conductive graphite and graphene. The ratio of any two major dimensions in a 3-D structure is less than 10.

[0043] In some examples, the active coating 130 is formed by a 3D printing method / process, some examples of which include, but are not limited to, binder jetting (e.g., using a liquid binder to bond layers of material to form a part) and bound powder extrusion (e.g., an extrusion-based metal additive manufacturing process).

[0044] In some examples, the substrate 120 supporting the active coating 130 is selected from the group consisting of blower blades, filter surfaces, housing surfaces, ionizer electrodes, chimney interior walls, scrubber components, and electrostatic precipitator components. In other words, the active coating 130 can be integrated into various components of the purification system. Thus, the functions of different components may overlap.

[0045] Example of operation 5 is a process flow diagram corresponding to a method 500 of purifying an influent stream 180 using the purification system 100, according to some examples. Various features and examples of the purification system 100 have been described above. For example, the purification system 100 includes an ionization purification device 110, which includes a substrate 120 and an active coating 130. The active coating 130 is disposed on the substrate 120 and includes a material 131 that is pyroelectric and / or piezoelectric. The composition of the material 131, other features of the active coating 130, and processing conditions (described further below) are specifically selected to enable the generation of negative ions during operation of the purification system 100, and more specifically, during operation of the ionization purification device 110, and even more specifically, when the influent stream 180 contacts the active coating 130.

[0046] In some examples, the method 500 includes flowing the inlet stream 180 into the ionization purification device 110 (block 510 of FIG. 5). The inlet stream 180 includes one or more contaminants 186, such as carbon monoxide, carbon dioxide, nitrogen oxides, hydrocarbons, and / or particulate matter. Other components of the inlet stream 180 may include, but are not limited to, air 182, water 184 (e.g., as water vapor), and / or other ionized components 188.

[0047] In some examples, the inlet stream 180 flows (into the ionization purification device 110) from one or more exhaust gas sources, such as an internal combustion engine, a burner, etc. Alternatively, the inlet stream 180 may be collected from the environment (e.g., ambient air, inside a home, inside a vehicle).

[0048] The method 500 proceeds by directing the inlet stream 180 towards the active coating 130 (block 540 of FIG. 5). Specifically, the inlet stream 180 is directed towards the active coating 130 while controlling the average pressure that the inlet stream 180 exerts on the active coating 130. As discussed above, this pressure is one of the driving forces, i.e., generating negative ions within the ionization purification device 110. In some examples, the average pressure within the muffler / tailpipe is between 0.25 bar and 2 bar, more specifically, between 0.50 bar and 1.25 bar. It should be noted that in some examples, the pressure may vary across the surface of the active coating 130.

[0049] Upon contact with the active coating 130, the inlet stream 180 generates negative ions 192 from one or more components of the inlet stream 180. In some examples, the rate of negative ion generation is between 15,000 and 25,000 per cubic centimeter per second. This rate depends on various factors, such as the composition of the inlet stream 180, the temperature of the inlet stream 180, the temperature of the active coating 130, the pressure that the inlet stream 180 exerts on the active coating 130, and / or the composition of the active coating 130. For example, the rate of negative ion generation increases with increasing temperature (of the active coating 130 and / or the inlet stream 180) and increasing pressure, as described above with reference to Figures 1B and 1C. Once the negative ions 192 are generated, the negative ions 192 begin to interact with one or more contaminants 186 to form purified material 194 in the outlet stream 190. Various examples of these interactions are described above with reference to Figure 1A.

[0050] In some examples, directing the inlet stream 180 to the active coating 130 (block 540) is performed while controlling the temperature of the inlet stream 180 before contacting the active coating 130 (block 542). One example of this temperature control is passing the inlet stream 180 through a temperature control device 150 before contacting the active coating 130 (block 544). Various examples of the temperature control device 150 are provided above (e.g., a heater and / or an air conditioner / chiller). In this example, the temperature control device 150 changes the temperature of the inlet stream 180 (e.g., cools the inlet stream 180 or heats the inlet stream 180) before the inlet stream 180 contacts the active coating 130. In some examples, directing the inlet stream 180 to the active coating 130 (block 540) is performed while controlling the temperature of the active coating 130 (block 545). For example, controlling the temperature of the active coating 130 can be accomplished using a temperature controller 150 that is thermally coupled to the active coating 130 (eg, integrated into the substrate 120).

[0051] In some examples, the inlet stream 180 is a vehicle exhaust. The exhaust temperature varies depending on the vehicle, engine size, driving conditions, ambient conditions, etc. For example, the temperature of the active coating 130 of a light vehicle when the inlet stream 180 contacts the active coating 130 may be between about 300-500° C.

[0052] In some examples, controlling the temperature of the active coating 130 (block 545) includes controlling the flow rate of the inlet stream 180 as it flows into the ionization purification device 110 (block 549). For example, the inlet stream 180 may be a heat source for heating the active coating 130, such as exhaust gas generated by an internal combustion engine and flowed into an exhaust system. As previously discussed, the active coating 130 may be positioned within the exhaust system, supported by various internal components of the system. The flow rate of the inlet stream 180, the temperature of the inlet stream 180, and the thermal isolation of the active coating 130 determine the temperature of the active coating 130.

[0053] In some examples, directing the inlet stream 180 toward the active coating 130 is performed while controlling the contact angle between the inlet stream 180 and the active coating 130 (block 550). As discussed above, this contact angle at least partially determines the average pressure that the inlet stream 180 exerts on the active coating 130. Other factors include the flow rate of the inlet stream 180 and the concentrations of various gases in the inlet stream 180.

[0054] In some examples, controlling the contact angle between the inlet stream 180 and the active coating 130 (block 550) includes flowing (552) the inlet stream 180 through a flow director 160. Various examples of the flow director 160 (e.g., nozzles, jets) are presented above.

[0055] In some examples, directing the inlet stream 180 to the active coating 130 is performed through a set of concentric structures 128, as shown, for example, in Figures 6A-6D. At least one of the concentric structures 128 can operate as a substrate 120 for the active coating 130. Additionally, at least another one of the concentric structures 128 includes a set of openings 127 that can operate as a flow director 160 to direct the inlet stream 180 to the active coating 130. In some examples, at least another one of the concentric structures 128 is an air filter. In the same or other examples, the set of concentric structures 128 is part of an automobile exhaust system.

[0056] In some examples, directing the inlet stream 180 towards the active coating 130 (block 540) is performed using a blower that can operate as the flow rate control device 140. In these examples, controlling the average pressure that the inlet stream 180 exerts on the active coating 130 includes controlling the rotational speed of the blower (block 554).

[0057] In some examples, the active coating 130 is enclosed within the ionization purification device 110, which blocks ambient light as the inlet stream 180 generates the negative ions 192 from one or more components of the inlet stream 180. In this manner, the negative ions 192 are generated in the absence of light, more specifically, sunlight. The ionization energy is derived from the interface between the active coating 130 and the inlet stream 180, more specifically, from heat and / or pressure at this interface as the inlet stream 180 contacts the active coating 130. Thus, in some examples, the active coating 130 is not exposed to sunlight as it generates the negative ions 192.

[0058] The method 500 proceeds by flowing the output stream 190 from the ionization purification device 110 (block 560). At this stage, the output stream 190 includes purified material 194. In some examples, a blower is positioned to direct the output stream 190 from the ionization purification device 110.

[0059] In some examples, the method 500 further includes separating (block 570) the purified material 194 from the effluent stream 190. For example, the effluent stream 190 can be passed through a filter, a scrubber, etc. Various examples of separation devices are within the scope.

[0060] Application Examples In some examples, the purification system 100 is used as part of a vehicle exhaust system 600, for example as shown diagrammatically in FIG. 6A. The vehicle exhaust system 600 may be part of a vehicle with an internal combustion engine, such as a gasoline engine, a diesel engine, a compressed natural gas (CNG) engine, etc. Referring to FIG. 6A, in some examples, the vehicle exhaust system 600 includes a catalytic converter 610, a connecting pipe 615, and a muffler 620. The purification system 100, more specifically, the ionization purification device 110, may be integrated into one or more of these components. For example, the active coating 130 may be positioned on the connecting pipe 615 and / or the muffler 620. The internal components of the muffler 620 may be specially configured to enhance the performance of the ionization purification device 110, as will now be described with reference to FIGS. 6B, 6C, and 6D.

[0061] Specifically, Figures 6B, 6C, and 6D show a set of concentric structures 128, at least one of which can act as a substrate 120 for an active coating 130. For example, the set of concentric structures 128 can be positioned within a muffler 620. In the same or other examples, the set can be used as a filter. At least another one of the set of concentric structures 128 includes a set of openings 127 that can act as a flow director 160 to direct an inlet stream 180 toward the active coating 130. For example, the arrangement of structures in Figures 6C and 6D is designed to interact with the vehicle exhaust gas stream exiting the perforated tube in the muffler while not impeding the linear horizontal flow of exhaust from the muffler toward the tailpipe.

[0062] Negative ion based purification offers a unique opportunity for purifying vehicle exhaust. Various thermal gradients within the vehicle exhaust system 600 can be used for negative ion generation by specific locations of the active coating 130 throughout the vehicle exhaust system 600. Additionally, water vapor present in the vehicle exhaust and part of the combustion process helps to induce the Lenard effect during this purification process. It should be noted that generally, water is not added to the inlet stream 180 prior to contact with the active coating 130. However, some examples of the inlet stream 180 (e.g., vehicle exhaust) already contain water as a component of the inlet stream 180.

[0063] It should be noted that the vehicle exhaust system 600 described above is not limited to automobiles and trucks, these features are also applicable to cruise / cargo ships, passenger ferries, airplanes, industrial machinery, equipment (chainsaws, lawnmowers, leaf blowers, etc.), etc.

[0064] 7A and 7B are two examples of industrial exhaust gas systems each including one or more ionization purification devices. Any chimney can be lined / melted / injected with the active coating 130, for example, as shown in these figures. The chimney and scrubber provide a larger surface area for positioning the active coating 130. Furthermore, various components that enable the operation of the purification system 100 besides the active coating 130 may already be present in these industrial exhaust gas systems. For example, the scrubber shown in FIG. 7A distributes water, which can induce the Lenard effect and assist in negative ion generation. Furthermore, the scrubber can include various flow control devices (e.g., blowers) for moving the industrial exhaust gas through the scrubber. These flow control devices can be operable to control the pressure applied to the active coating 130 by the inlet stream 180. Referring to FIG. 7B, the chimney carries hot exhaust gas. This thermal energy can be used by the active coating 130 for negative ion generation.

[0065] 8 is a schematic cross-sectional view of an ionizer with an integrated ionization purification device, according to some examples. One example of an ionizer is an electrostatic precipitator (ESP), which removes particles from a gas stream by using electrical energy to charge the particles either positively or negatively. In some examples, the electrodes of the ionizer can incorporate an active coating 130. In these examples, electrical energy is also used for negative ion generation.

[0066] In some examples, the active coating 130 can be positioned on various surfaces of heating, ventilation, and air conditioning (HVAC) systems used for indoor comfort and control. HVAC is a key component of residential structures (e.g., single-family homes, apartments, condominiums), hotels, senior living facilities, office buildings, vehicles (e.g., automobiles, trains, airplanes, ships, and submarines), or other spaces where conditions are regulated with respect to humidity, temperature, and the like. For purposes of this disclosure, HVAC refers to all types of systems (e.g., central HVAC systems, window units, standalone / portable heaters and air conditioners / coolers, etc.). For example, the active coating 130 can be positioned in / on air ducts, filter elements, blower blades, evaporator coils, and the like.

[0067] conclusion Although the foregoing concepts have been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems, and apparatus. Thus, the present embodiments are considered to be illustrative and not restrictive.

Claims

1. 1. A method for purifying an influent stream to form an effluent stream using a purification system, comprising: directing the influent stream into an ionization purification device of the purification system; the inlet stream comprises one or more contaminants; The ionization purification device comprises a substrate and an active coating disposed on the substrate, the active coating comprising a piezoelectric material selected from the group consisting of aluminum nitride, aluminum phosphate, barium titanate, bismuth titanate, gallium nitride, gallium phosphate, lithium niobate, lithium tantalate, lithium tetraborate, tourmaline, and triglycine sulfate. Pouring and directing the inlet stream at the active coating while controlling the average pressure the inlet stream exerts on the active coating; the inlet stream generates negative ions from one or more components of the inlet stream when in contact with the active coating due to the average pressure exerted by the inlet stream on the active coating by the piezoelectric effect, the negative ions interacting with the one or more contaminants to convert carbon dioxide and form a purified material in the outlet stream; To aim at directing the effluent stream containing the purified material from the ionization purification device; The method includes:

2. The method of claim 1 , wherein directing the inlet stream toward the active coating is performed while controlling a temperature of the inlet stream prior to contacting the active coating.

3. The method of claim 1 , wherein directing the inlet stream toward the active coating is performed while controlling the temperature of the active coating.

4. The method of claim 3 , wherein controlling the temperature of the active coating comprises controlling a flow rate of the inlet stream into the ionizing purification device.

5. The method of claim 1 , wherein directing the inlet stream toward the active coating is performed while controlling a contact angle between the inlet stream and the active coating.

6. 10. The method of claim 1 , wherein the active coating is encapsulated within the ionization purification device, the ionization purification device blocking ambient light as the inlet stream generates the negative ions from the one or more components of the inlet stream.

7. The method of claim 1 , wherein directing the inlet stream toward the active coating is through a set of concentric structures, at least one of which is operable as the substrate for the active coating.

8. 2. The method of claim 1, wherein directing the inlet stream toward the active coating is performed using a blower operable as a flow rate control device, and controlling the average pressure that the inlet stream exerts on the active coating comprises controlling a rotational speed of the blower.

9. The method of claim 1 , wherein the inlet stream fed to the ionization purification device comprises water.

10. The method of claim 1 further comprising separating the purified material from the effluent stream.

11. The method of claim 1, wherein the material of the active coating comprises two different of aluminum nitride, aluminum phosphate, barium titanate, bismuth titanate, gallium nitride, gallium phosphate, lithium niobate, lithium tantalate, lithium tetraborate, tourmaline, triglycine sulfate, and zinc oxide.

12. 10. The method of claim 1, wherein the substrate supporting the active coating is selected from the group consisting of a blower blade, a filter surface, a housing surface, an ionizer electrode, an inner chimney wall, a scrubber component, and an electrostatic precipitator component.

13. The method of claim 1 , wherein the active coating is a continuous coating and isolates the substrate below the active coating from the environment.

14. The method of claim 1 , wherein the active coating comprises a plurality of discrete particles positioned on a surface of the substrate.

15. The method of claim 1 , wherein the substrate is porous and the active coating comprises a plurality of discontinuous particles disposed within the substrate and spaced from a surface of the substrate.

16. The method of claim 1 , wherein the substrate includes holes such that the active coating forms a surface of the holes.

17. The method of claim 1 , wherein the active coating includes active coating holes such that the inlet stream is directed into the active coating holes.

18. The method of claim 7, wherein at least one other of the concentric structures comprises a set of openings operable as a flow director to direct the inlet stream toward the active coating.

19. 20. The method of claim 18, wherein at least another one of the set of concentric structures is an air filter or part of an automotive exhaust system.

20. The method of claim 1, wherein the inlet stream flows to the ionization purification device from an exhaust gas source selected from the group consisting of an internal combustion engine and a burner.

21. The method of claim 20, wherein the exhaust gas source is an internal combustion engine selected from the group consisting of a gasoline engine, a diesel engine, and a compressed natural gas (CNG) engine.

22. The method of claim 20, wherein the active coating is positioned on one or more exhaust system components selected from the group consisting of connecting pipes and mufflers.

23. The method of claim 3, wherein the temperature of the active coating is between 300 and 500°C.

24. The method of claim 1, wherein the average pressure is between 0.25 bar and 2 bar.

25. The method of claim 1, wherein the negative ions are generated at a rate between 15,000 and 25,000 per cubic centimeter per second.