Patent Application
20150140643
1. Field of the Invention
The present invention relates to biological odor control systems and methods of treating odorous gases with biological odor control systems.
2. Description of the Related Art
Removal of odorous compounds from influent gas streams is a major environmental concern. Typically, these odorous compounds are removed through chemical and physical processes using carbon media, such as activated carbon media. However, carbon has a limited life span and needs to be replaced regularly (at a relatively high cost). In addition, chemical scrubber systems may be used, e.g., for H2S removal. Such systems use various expensive chemicals, such as sodium hydroxide and sodium hypochlorite, and are often difficult or expensive to operate and maintain.
As a result of these drawbacks, biological treatment processes have emerged as an alternative for purifying odorous gases. Biological treatment systems use micro-organisms, such as bacteria, to break down the odor-causing compounds found in influent gas streams. Further, biological treatment systems often utilize vessels to pack media and microorganisms for the treatment process. However, because biological treatment systems require irrigation devices and various' other components, these systems have a large footprint, and an inconvenient, complicated layout of controls, piping, and other components. In addition, the media and microorganisms used in current biological odor treatment systems can allow residual odorous compounds to pass through into the environment.
Thus, a need exists for an improved biological odor control (BOC) system that addresses the various above-described drawbacks and deficiencies associated with current and existing systems and processes.
Accordingly, and generally, provided is an improved biological odor control system and method that addresses and/or overcomes various drawbacks and deficiencies associated with existing biological odor control systems and methods. Preferably, provided is an improved biological control system and method that exhibits a unique arrangement of components and resulting footprint at installation. Preferably, provided is an improved biological odor control system and method that utilize specified media and microorganisms, and/or processes.
In certain preferred and non-limiting embodiments or aspects, the present invention is directed to a biological odor control system that can include a vessel with a nutrient tank, water control panel, and an electrical control unit mounted onto an outer surface of the vessel. The nutrient tank can be mounted onto and attached to the outer surface of the vessel such that the nutrient tank does not extend into a housing of the vessel. The nutrient tank can also be monolithically formed to an outer surface of the vessel. The vessel can include a housing, a gas inlet, a gas outlet, a first media bed positioned within the housing of the vessel, and an irrigation system adapted to provide moisture, nutrients, and/or mixtures thereof to the first media bed. The first media bed can include an inert porous inorganic media and biological materials that facilitate the conversion and absorption of odorous compounds from a gas source. An unobstructed air flow chamber can be formed within the housing of the vessel. The gas inlet can include an exhaust fan adapted to draw odorous gas into the vessel, and the gas outlet can include an exhaust stack adapted to release deodorized gas into the environment. The gas outlet can also include an outlet fan.
In certain preferred and non-limiting embodiments or aspects, the biological materials of the first media bed can include a sulfur-oxidizing autotrophic microorganism. The sulfur-oxidizing autotrophic microorganism can be a bacteria selected from Thiobacillus thiooxydans, Thiobacillus thioparus, Thiobacillus intermedius, and/or combinations thereof. Further, the inorganic media of the first media bed can include expanded clay. In some embodiments, the vessel can also include a second media bed positioned within the housing that can adsorb odorous compounds from the gas source. The second media bed can include virgin activated carbon media, high H2S capacity carbon media, media adapted to remove ammonia and amines, and/or mixtures thereof.
In certain preferred and non-limiting embodiments or aspects, the vessel further includes a deck. In some of these embodiments or aspects, the nutrient tank and exhaust fan are mounted onto an outer surface of the deck. A sump can also be positioned within the housing of the vessel. A drain adapted to release water and acidic products from the sump can be attached to the vessel. Further, the vessel can rest on a sloped surface to allow water and other liquids to run to the side opposite the deck.
The vessel can have various designs including, but not limited to, a rectangular cross-section. In some of these embodiments or aspects, the water panel, the electrical control unit, the exhaust fan, and/or the nutrient tank are mounted on a same side of the vessel for a more compact system. To protect the various components mounted on the vessel from the environment and damaging weather conditions, a weather cover can be placed over at least a portion of the vessel. In addition, at least one or more of the vessel, the nutrient tank, the exhaust fan, and electrical control unit can be made of a fiber reinforced plastic, or optionally, polypropylene.
In certain preferred and non-limiting embodiments or aspects, the biological odor control system can be pre-assembled off-site at a facility remote or away from a site where the system will be shipped. By providing a pre-assembled biological odor control system, quality control testing is assured, improper installation at a jobsite is avoided, and installation costs and time are reduced.
In certain preferred and non-limiting embodiments or aspects, the present invention is also directed to a method of treating odorous gases. The method can include: drawing odorous gas into a housing of a vessel; distributing gas into a first media bed positioned within the housing of the vessel, where the first media bed can include inert porous inorganic media and biological materials that facilitate the conversion and absorption of odorous compounds from a gas source; distributing moisture, nutrients, or a combination thereof from an irrigation system into the first media bed where the nutrients are distributed to the irrigation system from a nutrient tank mounted onto and attached to an outer surface of the vessel such that the nutrient tank does not extend into a housing of the vessel; and releasing deodorized gas, e.g., into the environment. In addition, the method can include releasing water and acidic products from a sump positioned within the housing of the vessel. Optionally, in some embodiments or aspects, the method can also include distributing gas into a second media bed that can adsorb odorous compounds from the gas source.
In certain preferred and non-limiting embodiments or aspects, the present invention is also directed to a vessel for treating odorous gas. The vessel can include the various embodiments or aspects mentioned above and described in detail herein.
For purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard variation found in their respective testing measurements.
Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10.
Further, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lateral,” “longitudinal,” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the specification, are simply exemplary embodiments or aspects of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments or aspects disclosed herein are not to be considered as limiting.
In this application, the use of the singular includes the plural and plural encompasses singular, unless specifically stated otherwise. In addition, in this application, the use of “or” means “and/or” unless specifically stated otherwise, even though “and/or” may be explicitly used in certain instances. Further, in this application, the use of “a” or “an” means “at least one” unless specifically stated otherwise.
As indicated, in certain preferred and non-limiting embodiments or aspects, the present invention is directed to a biological odor control system 10. As shown in
Further, unlike other existing systems, the vessel 12 does not include (i.e., is completely free of) lifting eyes. As used herein, the term “lifting eyes” refers to components fastened onto the outside portions of a vessel 12 that are used to lift the vessel 12 vertically and/or pull the vessel 12 horizontally. A non-limiting example of a lifting eye is an eyebolt with a first threaded end for fastening to a vessel 12 and a second end shaped in the design of a ring for engaging the eyebolt for lifting. It has been found that lifting eyes are often misused and present potential safety hazards. By excluding lifting eyes from the vessel 12, misuse of the vessel 12 and potential safety hazards are avoided.
As further shown in
In certain preferred and non-limiting embodiments or aspects, at least a portion of the vessel 12, at least a portion of the deck 14, and/or other components described in detail below can be made of fiber reinforced plastic (FRP). As used herein, the term “fiber reinforced plastic” or FRP refers to a composite material made of a polymer matrix reinforced with fibers. A non-limiting example of a polymer matrix suitable for use in preparing at least a portion of the vessel 12 includes, but is not limited to, an epoxy vinyl ester resin. Epoxy vinyl ester resins that can be used are commercially available from Ashland, Inc. as Hetron® 922 and Derakane 411®. Other suitable epoxy vinyl ester resins are commercially available from AOC as Vipel F010®. As indicated, the polymer matrix can be reinforced with fibers. Non-limiting examples of reinforcing fibers include glass fibers. Suitable glass fibers that can be used include, but are not limited to, corrosion resistant borosilicate glass fibers. The resin materials of the polymer matrix can further include an inner veil of synthetic organic fibers, such as the inner veil commercially available from Precision Fabrics Group as NEXUS® 111-00010. The inner veil used in the corrosion layer can have thickness of at least 10 mils.
At least a portion of the vessel 12, the deck 14, and/or other components described in detail below can be fabricated through contact molding. As used herein, the term “contact molding” refers to a molding technique in which reinforcement fibers and resins are placed in a mold with cure taking place at room temperature with a catalyst/promoter system or under external influences such as heat. The vessel 12, extended deck 14, and/or other components described in detail below can be fabricated through contact molding in accordance with NBS PS 15-69, ASTM D3299-10, and ASTM D4097-01 (2010). Non-molded surfaces can be coated with resin incorporating paraffin.
Further, during fabrication of the vessel 12, the inner surface of all laminates can be resin rich and reinforced with an inner veil, such as NEXUS® 111-00010 described above, to form a corrosion liner. In certain embodiments or aspects, the interior corrosion liner can further include two layers of chopped strand mat. The corrosion liner can have a thickness of at least 100 mils. In addition, the structural laminate of the vessel 12 can include alternating layers of mat or chopped glass and a woven roving applied to reach a desired thickness. The exterior of the vessel 12 can also be coated with a white gel containing ultraviolet light inhibitors.
Referring again to
As shown in
After odorous gas enters the housing 13 of the vessel 12, it is distributed to at least a first media bed 24 where pollutants and undesirable compounds are removed (see, for example,
The media of the first media bed 24 can be randomly distributed into the housing 13 of the vessel 12 to allow a low pressure drop. The media that makes up the first media bed 24 can be supported within the housing 13 of the vessel 12 by a support system that includes a screen. For example, in certain embodiments or aspects, a high density polyethylene (HDPE) or FRP support device having a polypropylene screen can be used to hold the media of the first media bed 24.
In certain preferred and non-limiting embodiments or aspects, the first media bed 24 can include an inert porous inorganic media and biological materials. The inert porous inorganic media can include a high capacity inorganic material for selectively growing the biological materials. The biological materials can include, but are not limited to, sulfur-oxidizing autotrophic microorganisms, such as bacteria. Non-limiting examples of bacteria that can be used as the sulfur-oxidizing autotrophic microorganisms include Thiobacillus thiooxydans, Thiobacillus thioparus, Thiobacillus intermedius, and/or combinations thereof. The first media bed 24 is resistant to acidic conditions and is efficient at removing hydrogen sulfide and other undesirable compounds. The first media bed 24 also has a high surface area per unit volume to optimize gas to liquid contact. Further, the media used with the first media bed 24 is porous and does not degrade or compact, allowing consistent, predictable and efficient performance for the life of the biological odor control system 10. In one preferred and non-limiting embodiment or aspect, the media used with the first media bed 24 is an expanded clay media.
To provide moisture to the first media bed 24, an irrigation arrangement or system 26 can be incorporated into the vessel 12. As shown in
In certain embodiments or aspects, all or a substantial portion of the distribution apparatus 28 of the irrigation system 26 is positioned within the housing 13 of the vessel 12. For instance, the distribution apparatus 28 can enter at one end of the vessel 12 without being exposed at other areas of the vessel 12.
In certain preferred and non-limiting embodiments or aspects, a water panel 30 can be mounted onto an outer surface of the vessel 12, as shown in
In certain embodiments or aspects, nutrients can be distributed to the first media bed 24 to optimize growth of the sulfur-oxidizing microorganisms. Non-limiting examples of nutrients that can be added to the first media bed 24 include, but are not limited to, fertilizers. As used herein, the term “fertilizer” refers to a material or combination of materials which, when added to microorganisms, improves the rate of growth or health of the microorganisms. Non-limiting examples of ingredients that make up the fertilizers used as the nutrients include urea, nitrogen, phosphate, soluble squash, iron such as chelated iron, and/or mixtures thereof. The nutrients added to the first media bed 24 have been found to accelerate the acclimation process and improve hydrogen sulfide removal efficiency.
Referring to
In certain preferred and non-limiting embodiments or aspects, nutrients from the nutrient tank 34 can be controlled by the water panel 30. Referring to
During operation of the irrigation system 26, moisture and/or nutrients are distributed over the first media bed 24 as odorous gas is being pushed up through the housing 13 of the vessel 12 counter-current to the direction of the moisture and/or nutrients. As gas passes over the moist media, hydrogen sulfide and other compounds dissolve into the water film on the surface of the media. These dissolved compounds become available to the microorganisms residing in the first media bed 24 for oxidation to release energy used by the microorganisms for growth. When nutrients are added, the nutrients can enhance and sustain the biological activity of the first media bed 24. Further, the water that passes through the first media bed 24 can rinse away the acidic byproducts. In certain preferred and non-limiting embodiments or aspects, and referring to
In certain preferred and non-limiting embodiments or aspects, a concrete pad on which the vessel rests is sloped, which allows water to run to the side opposite the deck 14 (and drain by gravity). As shown in
In one preferred and non-limiting embodiment or aspect, the sump 38 is positioned substantially underneath the housing 13 of the vessel 12 in an area where the drain 40 is located. As discussed above, and in one preferred and non-limiting embodiment or aspect, the concrete pad is sloped from the fan area (on the deck 14) to the drain. This prevents water from entering or impacting the air chamber under the deck 14. This also allows the water to move to the side opposite the deck 14; again, where the drain 40 is located. The air flows from the exhaust fan 20 into the chamber 21 underneath the deck 14 and into the housing 13 bottom.
Optionally, in certain preferred and non-limiting embodiments or aspects, the vessel 12 also includes a second media bed 42 that is positioned in the housing 13 of the vessel 12 along with the first media bed 24 (see, for example,
In certain preferred and non-limiting embodiments or aspects, the second media bed 42 includes or comprises a material that is adapted to adsorb and remove volatile organic compounds (VOCs), insoluble organic compounds, hydrogen sulfide, ammonia, amines, and/or mixtures thereof. Non-limiting examples of media material that can be used for the second media bed 42 includes virgin activated carbon media, high H2S capacity carbon media, media adapted to remove ammonia) and amines, and/or mixtures thereof. Because most of the odorous compounds are absorbed by the first media bed 24, the second media bed 42 has an extended life span.
After odorous compounds are removed during the treatment process through the first media bed 24 and, optionally, the second media bed 42, deodorized gas can be released, such as into the environment, through the gas outlet 18. Referring to
Referring to
The electrical control unit 52 can control the processes and function of the entire biological odor control system 10. For example, the electrical control unit 52 can be used to control the exhaust fan 20 and detect when the fan 20 is malfunctioning. The electrical control unit 52 can also control the irrigation system 26 by controlling the solenoid valve, nutrient pump 36, and other controls housed in the water panel 30.
In certain preferred and non-limiting embodiments or aspects, referring to
In certain preferred and non-limiting embodiments or aspects, the biological odor control system 10 described herein can be pre-assembled prior to shipment. As used herein, “pre-assembled” refers to the assembly of various components of the biological odor control system 10 off-site at a facility remote or away from a destined site where the biological odor control system 10 will be shipped. For example, any combination of the vessel 12, exhaust fan 20, irrigation system 26, water panel 30, nutrient tank 34, exhaust stack 44, and electrical control unit 52 can be pre-assembled. Such assembly includes piping, wiring, and control testing. By providing a pre-assembled biological odor control system 10, quality control testing is assured, improper installation at a jobsite is avoided, and installation costs and time are reduced.
As described above, the various components of the biological odor control system 10 can be mounted directly onto an outer surface of the vessel 12. For example, the water panel 30, nutrient tank 34, exhaust fan 20, and/or electrical control unit 52 can all be mounted in close proximity to each other on an outer portion of the vessel 12. The resulting biological odor control system 10 is more compact than other systems with a small footprint allowing it to fit into small spaces. Further, by mounting the components onto an outer portion of the vessel 12, the vessel 12 exhibits an unobstructed, uniform distribution of air.
In addition, the electrical control unit 52 allows the biological odor control system 10 to be operated remotely with minimal operator maintenance and attention. Thus, water and nutrients can be automatically regulated with timers, automated controls, and the like. This ensures dependability of operation with minimized maintenance and downtime.
The biological odor control system 10 described herein also exhibits a hydrogen sulfide removal efficiency of at least 99%. The media used with the first bed 24 has a long life and requires minimal maintenance which lowers labor costs and system 10 downtime. The biological odor control system 10 also operates with consistent, low pressure drop across the media beds, which lowers operating power requirements and lowers operating costs.
While several embodiments or aspects of the invention were described in the foregoing detailed description, those skilled in the art may make modifications and alterations to these embodiments or aspects without departing from the scope and spirit of the invention. Accordingly, the foregoing description is intended to be illustrative rather than restrictive.
| Number | Date | Country | |
|---|---|---|---|
| 61904669 | Nov 2013 | US |
