Patent Application
20170176001
This invention relates to the field of waste incineration and more particularly to a system, method and apparatus for using an arc-formed gas in the process of neutralizing bio-hazardous material and/or in a secondary burn operation of fumes produced in the combustion of bio-hazardous waste.
Garbage and waste incineration is a widely accepted alternative to landfill for many reasons, including the amount of space taken by a land fill, transportation to the land fill, soil and water table pollution from leaching of toxins into the soil and aquifer beneath the land fill, various aromas, wild life attracted by a land fill (e.g. rats, birds), release of methane gas, and the overall unsightliness of a land fill. Furthermore, even well lined landfills run the risk of soil and water contamination due to earth shifting or sink holes. An incinerator is a system that burns waste material, typically including organic substances. The incinerator converts the waste material into ash, flue gas and heat and the heat is often used to generate power. Most incinerators require systems to clean the flue gas of the ash and other pollutants.
Incinerators have a bad reputation and municipalities are reluctant to provide permits for incinerators due to the high levels of emissions which typically require scrubbers in an attempt to clean the exhausts of combustion. For this reason, there is a lower level of usage of incinerators, leading to many of the above mentioned problems related to landfill.
Bio-hazardous waste is a byproduct of human activities. Bio-hazardous waste is often infectious, contaminated with blood or other bodily fluids. Bio-hazardous waste is known to be a carrier of infectious diseases and has the potential to infect those who are exposed to it. The U.S. Environmental Protection Agency (EPA) has established certain regulations for the waste disposal, for example, the Resource Recovery Act, which has been used by many states to regulate the disposal of bio-hazardous waste. In such, the “bio” typically indicates medical waste including all solids, liquids and gases that are hazardous are handled and disposed of by set processes. “Hazardous” refers to waste that is caustic, toxic, reactive to the atmosphere, flammable, etc. Examples of bio-hazardous waste include certain drugs, bandages, hypodermic needles/syringes, etc. Those who produce bio-hazardous waste must take steps to ensure that the bio-hazardous waste is properly handled and disposed under the EPA regulations.
For burning of bio-hazardous waste, flue gases need to reach a minimum temperature to ensure proper breakdown of toxic or contagious organic substances and must sustain that temperature for a period of time, usually a few seconds. For example, European standards require that in burning bio-hazardous waste, the flue gases need to achieve a temperature of at least 1,560 F for at least 2 seconds. To assure such temperatures, the incinerators require forced air convection systems and, for some waste, injection of auxiliary fuels in addition to the flammability of some of the bio-hazardous waste, for example, oil or natural gas, etc.
There are several pollutants produced when incinerating bio-hazard materials (e.g., medical waste), typically produced when burning plastics that are prevalent in medical waste. One particularly bothersome pollutant from incineration is dioxin. Dioxin is believed to be a serious health hazard. To breakdown dioxin, the molecular ring of dioxin must be exposed to a sufficiently high temperature so as to trigger a thermal breakdown of the molecular bond. This is one reason why European standards require achieving of a flue temperature of 1,560 F for at least 2 seconds, often requiring injection of additional fuel into the burning process. Another particularly bothersome pollutant is furan, a heterocyclic organic compound produced during the thermal degradation of certain materials. Furan is toxic and believed to be carcinogenic in humans.
Dioxins and furans are known to have a number of negative health effects. The U.S. Environmental Protection Agency (EPA) has indicated that dioxins and furans are likely a cancer causing substance to humans. Exposure to dioxins and furans has resulted in changes in hormone levels. High doses of dioxin have been known to cause a skin disease called Chloracne.
What is needed is an incineration system that uses an arc-formed gas to facilitate proper combustion of bio-hazard material and/or secondary combustion of fumes from a primary combustion of bio-hazard material to limit pollutants and bio-hazards that are emitted into the atmosphere.
A system for incinerating bio-hazardous waste using an arc-formed gas includes a series of primary combustion chambers into which an amount of bio-hazardous waste flows, each having a source of combustion interfaced there to, thereby providing heat and ignition to the bio-hazardous waste. In one embodiment, each of the plurality of primary combustion chambers burns at different temperatures than the others. An exhaust interfaced to the primary combustion chambers, the exhaust extracting fumes from the primary combustion chambers. In some systems, an arc-formed gas is combined with the exhausts and the combination is burned in a secondary combustion chamber. In some systems, the arc-formed gas is combined with another fuel such as oil or natural gas for the desired burn characteristics or for economic reasons.
In one embodiment, a system for incinerating bio-hazardous waste is disclosed including a chamber having there within a hydrocarbon feedstock and a plurality of electrodes between which an electric arc is formed, producing an arc-based gas. The system includes at least one primary combustion chamber in which an amount of bio-hazardous waste is incinerated. A source of combustion is interfaced to each of the at least one primary combustion chambers, thereby providing heat and ignition to the bio-hazardous waste. A secondary combustion chamber accepts fumes from the at least one primary combustion chamber and combines the fumes with the arc-formed gas and then the fumes mixed with the arc-formed gas are combusted.
In another embodiment, a system for incinerating bio-hazardous waste is disclosed including at least one primary combustion chamber in which an amount of bio-hazardous waste is incinerated. A source of combustion interfaced to each of the at least one primary combustion chambers, thereby providing heat and ignition to the bio-hazardous waste. The system includes a secondary combustion chamber in which fumes from the at least one primary combustion chamber is combined with an arc-formed gas and then the fumes mixed with the arc-formed gas are combusted.
In another embodiment, a system for incinerating bio-hazardous waste is disclosed including at least one primary combustion chamber in which an amount of bio-hazardous waste is incinerated. A source of combustion interfaced to each of the at least one primary combustion chambers, thereby providing heat and ignition to the bio-hazardous waste, whereas a temperature of at least one of the at least one primary combustion chamber is raised using the arc-formed gas. An exhaust is interfaced to the primary combustion chambers, the exhaust extracting fumes from the at least one combustion chamber.
The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which:
Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures.
Throughout this description, the apparatus is described as a system for incinerating bio-hazardous waste, in which, the term “bio-hazardous waste” is meant to be the most generic interpretation as possible, in which, the material being incinerated may include any type of materials often found in bio-hazardous waste, including, but not limited to, plastics, cardboard, cloth, baby diapers, adult diapers, bandages, syringes, disposable breathing apparatus, etc. Note that it is fully anticipated that the stated bio-hazardous waste includes other waste that is potentially not a hazard or contains the bio-hazardous waste, for example paper products, pens, pencils, food service items, etc., as such are sometimes improperly included in bio-hazardous waste containers.
Referring to
One exemplary feedstock 22 is oil, and more particularly, used vegetable or animal oil such as that from deep-fat fryers, etc. Of course, any oil is anticipated, including unused vegetable oil and oil from animal fat.
Any feedstock 22 is anticipated either in fluid form or fluid mixed with solids, preferably fine-grain solids such as carbon dust or metallic fragments, etc.
In one example, the feedstock 22 is vegetable oil and the electrodes 14/16 are carbon, the oil molecules separate within the plasma 18 of the electric arc into the arc-formed gas 24, typically including hydrogen (H2) and carbon monoxide (CO) atoms, which percolate to the surface of the feedstock 22 for collection (e.g. extracted through a collection pipe 26. This arc-formed gas 24 is similar to synthetic natural gas or syngas, but arc-formed gas 24 produced though this process behaves differently and produces a higher temperature burn. In embodiments in which at least one of the electrodes 14/16 that form the arc 18 is made from carbon, the electrode(s) 14/16 and serves as a source of charged carbon particles (e.g. carbon nanoparticles) that become suspended within the arc-formed gas 24 and are collected along with the gas 24, thereby changing the burning properties of the resulting arc-formed gas 24.
In examples in which the feedstock 22 is a petroleum-based liquid, the exposure of this petroleum-based feedstock 22 to the arc (as above) results in a gas that includes polycyclic aromatic hydrocarbons which, in some embodiments, are quasi-nanoparticles that are not stable and, therefore, some of the polycyclic aromatic hydrocarbons will form/join to become nanoparticles or a liquid. Therefore, some polycyclic aromatic hydrocarbons as well as some carbon particles/nanoparticles are present in the resulting arc-formed gas 24. In some embodiments, some of the carbon particles or nanoparticles are trapped or enclosed in poly cyclic bonds. Analysis of the produced arc-formed gas 24 typically includes polycyclic aromatic hydrocarbons that range from C6 to C14. The presence of polycyclic aromatic hydrocarbons as well as carbon particles or nanoparticles contributes to the unique burn properties of the resulting arc-formed gas 24. This leads to higher burning temperatures.
In another example, when the feedstock 22 is petroleum based (e.g. used motor oil) and at least one of the electrodes 14/16 are carbon, the petroleum molecules separate within the plasma of the electric arc 18 into the arc-formed gas 24 that includes hydrogen (H2) and aromatic hydrocarbons, which percolate to the surface of the petroleum liquid 22 for collection (e.g. extracted through a collection pipe 26. In some embodiments, the arc-formed gas 24 produced though this process includes suspended carbon particles since at least one of the electrodes of the arc 18 is made from carbon and serves as the source for the charged carbon particles or nanoparticles that travel with the manufactured hydrogen and aromatic hydrocarbon arc-formed gas 24 and are collected along with, for example, the hydrogen and aromatic hydrocarbon molecules, thereby changing the burning properties of the resulting arc-formed gas 24, leading to a hotter flame. In this example, if the feedstock 22 is oil (e.g. used oil) and the arc-formed gas 24 collected includes any or all of the following: hydrogen, ethylene, ethane, methane, acetylene, and other combustible gases to a lesser extent, plus suspended charged carbon particles or nanoparticles that travel with these gases. Note that it is fully anticipated that the arc-formed gas 24 be compressed and/or liquefied for storage and transportation.
Referring to
In the exemplary bio-hazard incineration systems shown in
In order to achieve these higher temperatures, the arc-formed gas 24 (alone or with other gases) is injected into the primary incineration chambers 100/110/120 through a feed line 26 (e.g. from the exemplary system for the production of a combustible fluid described above). The arc-formed gas 24, either alone, or in conjunction with another fuel such as oil or natural gas, produces a significantly higher temperature. The increased temperatures provide for improved decontamination of the bio-hazardous waste 90, in particular, improved breakdown of pathogens as well as metals and other pollutants such as dioxins. Either the gas 24 alone or a combination of the arc-formed gas 24 and other fuels (or ohmic heating) produces the high temperatures needed to decontaminate and reduce the bio-hazardous waste 90. In some embodiments, the conveyor system 105 includes other features for separation of the reduced bio-hazardous waste 90 such as air jets for separating metal fragments, etc., which are not shown for clarity reasons.
Although any number of kilns 100/110/120 operating at any temperature, either different temperatures or the same temperature are anticipated, one exemplary set of kilns 100/110/120 is shown for clarity reasons. In this exemplary system, the bio-hazardous waste 90 enters into the first kiln 100 where it is exposed to a first temperature generated by, for example, a burner 102 fed by the arc-formed gas 24 or the arc-formed gas 24 mixed with other gases (e.g. oxygen, natural gas, etc.). The first temperature is around 800 degrees Fahrenheit which burns any plastics from the bio-hazardous waste 90.
Residue from the first kiln 100 is carried by the conveyor 105 to the second kiln 110 where it is exposed to a second temperature generated by, for example, a burner 112 fed by the arc-formed gas 24 or the arc-formed gas 24 mixed with other gases (e.g. oxygen, natural gas, etc.).
The second temperature is around 1600 degrees Fahrenheit which completes the burning of the plastics from the first kiln 100 and also melts metals that have a lower melting point such as lead (e.g., solder).
Residue from the second kiln 110 is carried by the conveyor 105 to the third kiln 120 where it is exposed to a third temperature generated by, for example, a burner 122 fed by the arc-formed gas 24 or the arc-formed gas 24 mixed with other gases (e.g. oxygen, natural gas, etc.). The third temperature is around 3000 degrees Fahrenheit which melts metals that have a higher melting point such as copper and precious metals.
Residue from the third kiln 120 is carried by the conveyor 105 to a cooling and storage, where the remaining residue 92 is, for example, sorted to extract useful materials such as gold and silver.
In some embodiments, exhaust gases from the kilns 100/110/120 are directed into a secondary burn chamber 150 through exhaust ducts 134. In some embodiments, the exhaust mechanism 145 treats and/or scrubs the exhaust gases by, for example, cooling the exhaust gases or filtering the exhaust gases.
In some embodiments, the exhaust gases are optionally cooled by a chiller 143 and then mixed with the arc-formed gas 24 from a gas feed line 182 before entering the secondary burn chamber 150 where the exhaust gases and the arc-formed gas 24 are combusted.
The exhaust gases flow from the kilns 100/110/120 through vents 104/114/124 into an exhaust system 134. In some embodiments, the exhaust system releases the exhaust gases into the atmosphere (not shown).
In the exemplary bio-hazard incineration system shown in
In the exemplary bio-hazard incineration system shown in
Note that, since the burning of the bio-hazardous waste 90, along with other fuels (e.g., oil, gas, and/or the arc-formed gas 24 as produced above) generates significant heat, it is fully anticipated that, in some embodiments, the excess heat is used to generate power using one or more power generators 130/160 (e.g. electrical power 161) using, for example, a steam turbine 130/160 or fuel cell 130/160.
In summary, the arc-formed gas 24 produced within the arc 18 is used in any or all of the following incineration steps: the arc-formed gas 24 is used in the primary burning chambers 100/110/120 to increase the temperature at which the bio-hazardous waste 90 is burned; the arc-formed gas 24 is mixed with flue gases from the primary incineration of the bio-hazardous waste 90 and, the mixed flue gases and the arc-formed gas 24 (see above) are burned in a secondary burn chamber 150, completely burning all exhaust fumes from the primary burning process. In all cases, it is anticipated that the arc-formed gas 24 is either used as a sole fuel to facilitate combustion, or the arc-formed gas 24 is used in conjunction with another fuel including, but not limited to, oil, propane, natural gas, synthetic natural gas, diesel, gasoline, etc., depending upon temperatures required and economic factors.
In some embodiments, the primary burn process in the primary burn chambers 100/110/120, after initiation, continues through self-combustion of the bio-hazardous waste 90 being incinerated in the primary burn chambers 100/110/120, without further injection of other fuels (e.g. the arc-formed gas 24).
Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result.
It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.
This application claims the benefit of U.S. provisional application No. 62/269,232 filed on Dec. 18, 2015, the disclosure of which are incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62269232 | Dec 2015 | US |
