Patent Application
20200368796
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction of the patent document or the patent disclosure, as it appears in the U.S. Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. The following notice applies to the disclosure provided herein and to the drawings that form a part of this document: Copyright 2019-2020, Julius B. CO and Roderick S. DAYOT; All Rights Reserved.
Example embodiments of the present invention relate generally to medical waste management and more specifically to a method and apparatus for treating waste material using hot nitrogen gas as a better alternative non-burn technology.
Waste materials, such as medical waste made of plastic, cloth, paper, cellulose, etc., are usually burned in incinerators where incomplete combustion is the normal process that produces pungent smoke where to counter such result is done with expensive flue gas treatment processes that would ensure environmental safety and protection. Besides the use of incinerators, another non-burning method of treating medical waste is the use of an autoclave wherein high pressure and high temperature steam is produced from the boiler and is used to disinfect the medical waste through direct injection in the waste chamber. The aforesaid introduction of steam to the medical waste has been observed to be insufficient in disinfecting the waste since the distribution of heat and heat transfer is uneven during treatment. Furthermore, the steam being applied converts into water at a fast rate such that the moisture from the steam becomes a wastewater, which requires another treatment, and medical waste with water from steam becomes wet, heavy, and odorous. Another form of treatment of medical waste is the microwave where the waste material is subjected to microwave radiation for heating. The said heating however needs moisture to excite water molecules to produce heat and the temperature produced is 115 degrees Celsius, which is below disinfection temperature that is 121 degrees Celsius requiring more energy to achieve high temperature. In addition, the microwave waste treatment is utilizing a microwave generator that is very sensitive to moisture, can be damaged easily, and is expensive. Yet another form of treatment of medical waste is the pyrolysis method where waste is thermally decomposed in the absence of oxygen during heating within a designated chamber resulting in a byproduct of char or carbonized material. The source of heat is a high temperature plasma torch or burner that directly or indirectly heats the waste. The said treatment however cannot achieve a complete oxygen free environment that compromises the pyrolysis process as oxygen is technically present in the system that creates combustion, which is considered incineration. In matters of incineration, medical and hazardous waste, such as plastic materials and other organic materials have different heating values such that they react differently when subjected to burning, such that exhaust gases discharged from these incinerators contain polluting components, like smoke, dust, hydrogen chloride, carbon monoxide, Sox, Nox, and heavy metals that includes mercury, dioxin and furan, which are considered harmful pollutants. From the standpoint of environmental protection, it is necessary that formation of these harmful substances should be prevented during waste disinfection treatment.
Of these polluting components, dioxin and furan have extremely strong toxicity such that collection and removal of these is extremely important. Plastics from medical waste should therefore have to be conditioned such as drying, shredding and segregating to achieve complete combustion along with the other gases generated by the other organic materials. This will ensure reduction to safety level the toxic gases coming from the exhaust of the incinerator.
Burning of these medical wastes requires high temperature, preferably above 800 to 1200 degrees Celsius, to facilitate complete combustion and elimination of toxic gases generated by such medical waste. However, in conventional incinerators such temperatures cannot be attained since it will require a tremendous amount of fuel, thus rendering it to be too costly to do.
An example of the incinerator of the prior art is the conventional refuse incinerator facility, wherein a boiler and auxiliary burner are used. The refuse is directly burned in order to raise the temperature of the incinerator and the temperature of boiling water in the boiler. At the initial start of the operation, there is already a production of a low-temperature combustion gas which inflicts damage to the facility due to low-temperature corrosion build-up. To solve this problem, the common practice is to discharge this combustion gas by way of a bypass duct and stack. However, there is still the possibility that dust containing hazardous substances, such as dioxin, remain in the incinerator and boiler. If such contamination substances are deposited and still remain in the incinerator, they may be emitted and discharged as gaseous dioxin into the atmosphere even during normal operation.
Another example is an exhaust gas treating apparatus wherein the refuse is incinerated and then completely combusted by a secondary burner in a secondary combustion chamber. The ashes are then discharged to the atmosphere while the exhaust gas generated by the combustion is subjected to heat recovery by a waste heat boiler and waste heat reclaimer (pre-heater) as it flows towards a quenching reaction tower. The exhaust gas in the quenching reaction tower is sprayed with slaked lime slurry to remove hydrogen chloride (HCL) and sulfur oxide (SOx). Smoke dust, fly ash, HCL, SOx, heavy metals and dioxins, which remain in the exhaust gas, are then removed in a bag filter. The exhaust gas after treatment in then discharged to the atmosphere.
Although the exhaust gas from an incinerator is treated with the aforesaid process, there is the possibility that dioxin cannot be reduced to the desired low concentration. Dioxins generated during incineration are almost decomposed in the secondary combustion chamber; however, it is necessary to decrease the temperature of the exhaust gas from a high temperature of about 350 to 900 degree centigrade to a low temperature during every step of the process. However, there is still the tendency of dioxins regenerating at the vicinity of 300 degrees Centigrade during every step of the process such that the above-mentioned conventional exhaust gas treatment apparatus cannot effectively collect and remove dioxins at the desired low concentration.
The example embodiments of the present invention as herein disclosed provide treatment of waste materials wherein biodegradable and non-biodegradable waste materials, in particular medical waste, such as plastic, paper, cellulose, etc. are subject to a disinfection process such that high temperature nitrogen gas is utilized as a heat medium to facilitate effective treatment. Nitrogen gas disinfection is defined in the example embodiments of the present invention as the disinfection process of heating infectious medical waste and other waste material elements without oxidation through heat transfer from a hot nitrogen gas environment in which the thermally heated nitrogen gas is introduced into the waste chamber that displaces air and other gas and the waste is effectively disinfected without burning. The novel process reduces the waste into a gas or changes its phase into a gaseous form because the process is without the presence of air and oxygen. Furthermore, the example embodiments of the present invention are capable of disinfecting such waste through utilization of a heater that raises the nitrogen gas temperature generated by the apparatus. The example embodiments of the present invention further utilize an environmentally compatible non-oxidant, non-combustible gas, such as cheap and readily available nitrogen gas in combination with a heating system assisted with an external heater for high temperature disinfection. The gas being emitted by the example embodiments of the present apparatus is pollutant-free since only nitrogen gas is used and no chemicals are added in the process.
In view of the aforesaid problems of the prior art, it is therefore an object of example embodiments of the present invention to provide a method and apparatus for disinfecting waste materials, which can remedy the above-described drawbacks of the prior art including the drawbacks of the present non-burn technologies, such as autoclave, microwave, and pyrolysis methods, which are expensive to manufacture, operate, and maintain.
A further object of the example embodiments of the present invention is to provide an apparatus for treating waste, which can be used for heating and treating other waste materials such as garbage and like materials that require disinfection. The example embodiments of the present invention are very easy to operate and can be used in cities and hospitals for their medical and garbage waste management. Other objects and advantages of the example embodiments of the present invention may be realized upon reading the following description taken in conjunction with the accompanying drawings.
Embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which:
Referring to the drawings,
In another embodiment of the present invention described in
The method for treating waste material of an example embodiment includes among the following steps or actions. Heat nitrogen at a high temperature until it is transformed into superheated nitrogen. Said heating can be facilitated by suitable burning or heating means, such as a burner or an electric heater. The superheated nitrogen is then allowed to flow within a chromium and nickel pipe connected to the waste treatment chamber means such that heat is generated from said superheated nitrogen. Said high temperature heat inducted/transferred by the hot nitrogen in the heat chamber is then indirectly transferred to the waste heating chamber to facilitate disinfection of the waste being treated. When treating biodegradable and non-biodegradable medical or garbage waste material, such as plastic, wood, paper, cellulose, etc. by means of thermal disinfection, the temperature within the waste heating chamber should be at 120 to 300 degrees Celsius. In case the waste to be treated is infectious medical waste, the heating temperature in the waste heating chamber is regulated at minimum temperature to about 121 degrees Celsius to facilitate disinfection and kill the pathogens in the waste. At this temperature, no pathogens and viruses can survive after disinfection.
This non-provisional patent application draws priority from U.S. provisional patent application Ser. No. 62/850,844; filed May 21, 2019. The entire disclosure of the referenced patent application is considered part of the disclosure of the present application and is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62850844 | May 2019 | US |
