Patent Application
20170248307
This invention relates to incinerators and has particular relation to industrial and municipal-type incinerators for burning coal, wood, and waste material.
Industrial incinerators of the prior art may include one or more combustion chambers comprising drying grates and a flue for discharging gaseous by products from the combustion of combustible materials to the atmosphere. The amount of gas and other byproducts, such as ash, that may be discharged will vary based upon the combustion efficiency of the incinerator design. The vast majority of incinerator designs are not capable for completely or nearly completely combusting the materials such that the byproducts include substantial amounts of noxious gas and undesired uncombusted particulate.
Some more recent incinerator designs include scubbers that clean the gas byproducts so toxic and dangerous gas and particulates are removed prior to release to the atmosphere. A downside to such flue gas cleaning methods and systems is the substantial costs and complex construction. Moreover, some of such scrubbers have proven ineffective to meet environmental regulatory codes.
A further advancement in incinerator designs is a vortex incinerator such as disclosed in U.S. Pat. No. 3,577,940. The incinerator disclosed includes a combustion chamber and a means for introducing a mixture of waste material and primary air into the chamber. A means for establishing a vortical movement of the waste material is provided, as well as a means for igniting the waste material during its vortical movement. A secondary air source is introduced into the chamber at a plurality of regions which are spaced along the length of the chamber to maintain the vortical movement of waste material. A discharge flue port has an open end opening in the chamber, and a second discharge port includes an open end opening in the chamber for discharging from the chamber during the burning process non-combustible material entrained in the outer region of the vortex. The material discharged by the second port is conveyed through a conduit to a separator which separates the gases and the solid material and means are provide to introduce the separated gases and any solid particles suspended therein back into the combustion chamber. The burning waste material moves in the vortical path for the waste material to be entrained back into the outer region of the vortex for continuous burning until complete combustion has been achieved.
A shortcoming of the system disclosed in U.S. Pat. No. 3,577,940 is that it is limited to the incineration of municipal waste materials, and is unsuitable for use to burn denser energy fuels, such as coal, coal fines, or petroleum coke.
The present invention is an improvement on the earlier vortex incinerator. The disclosure of U.S. Pat. No. 3,577,940 is hereby incorporated by reference. Rather than be limited to incinerating municipal solid waste, the present invention is suitable for burning denser energy substances, such as coal, both high and low sulfur coal, waste coal fines, and petroleum coke. In some embodiments, the present invention is adapted to burn biomass, such as coconut shells, switchgrass, and wood waste. In some embodiments, the present invention may be used to incinerate waste tires. The improvement to the earlier vortex incinerator that enables it to burn different combustibles includes a pulverizer for reducing the aforementioned combustible materials into an appropriate size. Although the improvement is referred to as a pulverizer, it should be understood that this is not limited to a device that grinds or crushes material, but may also cut, shred, or otherwise reduce the size of the combustible material where appropriate, such as with certain biomass combustibles or waste tires.
In addition to the pulverizer, a further improvement over the aforementioned vortex incinerator is the use of a pneumatic feeder to introduce the pulverized combustible material into the combustion chamber.
The incinerator system of the present invention comprises an incinerator that is similar to that disclosed in U.S. Pat. No. 3,577,940. The incinerator includes a horizontally extending combustion chamber having spaced end walls and side wall, through which a mixture of combustible material and air is vortically moved and burned. The combustion chamber includes a tangentially directed inlet adjacent to one end wall for the introduction of a mixture of combustible material and air. Adjacent to the opposite end wall, an exhaust flue is positioned concentrically with a longitudinal axis of the combustion chamber to vent gases. Also adjacent to the end wall opposite the inlet means is an outlet means extending tangentially from the chamber periphery for the discharge of solid material. Further included is an igniter for igniting the combustible material during its vortical movement, and an exhaust flue adjacent to the other end wall of said combustion chamber positioned concentric with the combustion chambers longitudinal axis and having an open end opening into said combustion chamber. The incinerator further including a second port in the said combustion chamber wall adjacent the other end thereof and communicating with an outlet conduit for discharging from said combustion chamber residual combustible material and non-combustible material.
The system further includes a pulverizer adapted to receive combustible material and reduce the particle size. The pulverizer is adapted to crush into desired sized particles coal, waste coal, petroleum coke, waste tires, or brittle biomass. The preferred size of the pulverized material to be pulverized is in the range of approximately 3.715 mm to 50 mm in diameter. After being pulverized, the particles will be in essentially a powder form and have a size of approximately 0.0118 mm to 0.0059 mm (or mesh size of 50 to 100 mesh). The reduction of even municipal solid waste to specific size and moisture content has also been determined to improve the incinerator system by having the pulverized material be less than 8 mm in size and have less than 10% moisture content. A pneumatic blower is preferably configured to collect the crushed or pulverized material and blow it to the inlet port of the combustion chamber. The desired feed rate depends on the particular combustible material. For example, with eastern higher sulfur coal, an appropriate feed rate of between approximately 27 kilograms per hour and 158 kilograms per hour was determined for a particular combustion chamber. The feed rate may be controlled by a controller.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
It is noted that the drawings of the invention are not to scale. The drawings are merely schematic representations, not intended to portray specific parameters of the invention. The drawings are intended to depict only typical embodiments of the invention, and therefore should not be considered as limiting the scope of the invention. The invention will be described with additional specificity and detail through the use of the accompanying drawings. In the drawings like numbering represents like elements between the drawings.
Referring to
The pulverizer 34 includes an intake 36 into which the combustible material is fed. The intake 36 includes an open end 40. After being reduced in size, the pulverized material is drawn into a pneumatic conveying system including a blower 36 operated by a motor which blows the pulverized material through a pipe 44 to the combustion chamber 12. The pulverizer 34 and blower 36 are operatively connected to a controller 38, which controls the operation of the pulverizer and blower 36.
The combustion chamber 12 may be of any suitable configuration and is preferably cylindrical including a pair of spaced end walls 14 and 16 connected by an annular side wall 18. The end walls 14 and 16 may, if desired, include access ports or may be detachable for maintenance of the chamber 12.
If desired, the end wall 26 of the chamber 22 may include an access door 30 to permit access to the interior of the chamber 22. If also desired, end walls 24 and 26 can be adjustably releasable to facilitate easier maintenance of the chamber 22. The walls of the chamber 12 may be formed of any suitable material such as low carbon steel and be lined with one or more inner layers of any suitable refractory material such as fire brick. In the embodiment illustrated, the inlet conduit, such as pipe 24 enters the chamber 12 tangentially of the side wall 18 adjacent the end wall 16.
Continuous injection of a mixture of size-reduced waste material and air into the chamber 12 from the pipe 24 tangentially to the side wall 18 establishes a vortical flow of the waste material which travels from adjacent the end wall 16 toward the end wall 14. The particular point of entry of pipe 24 may be altered to create different vortices.
The pulverizer 34 is adapted to crush into desired size particles coal, waste coal, petroleum coke or brittle biomass. The preferred size of the pulverized material to be pulverized is in the range of approximately 3.715 mm to 50 mm in diameter. The moisture content of such combustible material is preferably less than 5%. Some materials, such as coal and petroleum coke may have slight oil content. After being pulverized, with coal, waste coal, petroleum coke or brittle biomass, the particles will be in powder form and have a size of approximately 0.0118 mm to 0.0059 mm (or mesh size of 50 to 100 mesh). With other materials, such as municipal solid waste, the size of the material after being pulverized is preferably less than 8 mm, and having a moisture content of less than 10%. In some embodiment, such as with municipal solid waste, a drier 64 may be included that reduces the moisture content of the combustible material. A pneumatic blower 36 is preferably configured to receive the crushed or pulverized material and blow it to the inlet port of the combustion chamber through pipe 20. The desired feed rate depends on the particular combustible material. For example, with eastern higher sulfur coal, the feed rate was between approximately 27 kilograms per hour and 158 kilograms per hour. With municipal solid waste, the feed rate is approximately 150 kilograms per hour to 500 kilograms per hour. The feed rate may be controlled by a controller 50 operatively connected to the pulverizer 34 and blower 36.
In order to ignite the waste material entering the chamber 12, a suitable commercially available igniter, such as burner 26, is included near the end wall 16 of the chamber 12. The burner 26 can be fueled with natural gas or propane gas for remote applications. Where the combustible material is continuously fed, the burner may be deactivated after initial ignition of the combustible material is completed.
In order to enhance combustion of the waste material and to maintain the energy of its vortical flow in a predetermined and controlled manner through the entire length of the combustion chamber, provision is made for introducing controlled quantities of high velocity secondary air into the chamber 12 during the burning process and at spaced regions throughout the length of the chamber. Additional blower or blowers 54 may be included to introduce secondary air into chamber 12. Additionally, in the described arrangement, the tangential injection of the secondary air has the beneficial effect of periodically contributing to the vortex energy in the chamber. Thus, compensation is provided for losses in vortex energy or for effectively sustaining the vortex as the waste material progresses vertically along the length of the chamber.
In order to discharge gaseous products of combustion from the chamber 12 to atmosphere first discharge means is provided including a discharge port or flue 28 having an open end opening in the chamber in the region of the end wall 14 and substantially concentric with the central longitudinal axis of the chamber 12. The flue 28 includes a hollow cylinder 58 of any suitable material extending through an opening of the end wall 14.
In a preferred embodiment, a second discharge means is provided for discharging from the chamber 22 during the burning process residual combustible material and noncombustible material. For this purpose the preferred embodiment provides a second discharge port 30 in the region of the end wall 24 for receiving and discharging from the chamber residual combustible material and noncombustible material which are entrained in the outer region of the vortex. Port 30 comprises a conduit extending through the sidewall 18 and leads via conduit 32 to suitable separator and disposal means as is described in U.S. Pat. No. 3,577,940, and is incorporated herein by reference.
Referring to
Although the invention has been described with reference to certain specific embodiments thereof, numerous modifications are possible and it is desired to cover all modifications falling within the spirit and scope of the invention.
This application is a continuation of U.S. provisional patent application Ser. No. 63/300,170, filed on Feb. 26, 2016, the disclosure of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 62300170 | Feb 2016 | US |
| Child | 15443852 | US |
