Patent Application
20090208891
This application is an original application based on U.S. Provisional patent application having Ser. No. 61/066,251, filed on Feb. 19, 2008 and U.S. Utility patent application having Ser. No.
The invention disclosed and claimed herein deals with a new insulation device that is a self supporting kiln insulation cover.
Commonly used at cement and asphalt plants, kilns, especially rotary kilns are found in many manufacturing processes, including the chemical, pharmaceutical, food processing, agricultural and highway material industries. Rotary kilns are large horizontal cylinders set up on a slight angle, rotating to mix materials together and depending on gravity to work the material down the length of the kiln. Rotary kilns can range from 30 800 feet in length and range between 12 and 20 feet in diameter.
Rotary kilns are not the only structures for kilns, as kilns for various manufacturing processes take on other configurations, such as square, triangular, etc.
Kilns are fueled by materials such as petroleum, natural gas, oil, coal, and even used tires and other industrial waste. The kilns operate at high temperatures in order for chemical reactions to occur and the gas flame shooting down the middle of the tube-like structure can often reach 3400° F. (1870° C.), about one third of the temperature of the sun's surface. With the heat of this machine reaching such extremes, the question of energy efficiency is often associated with kilns.
Kilns are insulated with firebrick sandwiched in between the outside metal cylinder and the inside layer. This structure allows for the outside shell to still become very hot, and some studies suggest that an estimated forty percent of total input energy is being lost. Attempts to conserve this energy have been made in the past, but most of them have consisted of putting insulation directly on the surface of the outside rotating shell. Over a period of time, this resulted in a sagging egg shaped layer of insulation hanging around the kiln.
Such insulation methods can be found for example, in U.S. Pat. No. 4,932,863 that issued on Jun. 12, 1990 to Anderson, in which a drum dryer for use in the manufacture of bituminous concrete asphalt is provided with a jacket that is insulated. The jacket is strapped directly to the outside of the drum wall.
In addition, U.S. Pat. No. 5,695,329, that issued Dec. 9, 1997 to Orcutt, deals with an outer jacket that is mechanical attached directly to the outside surface of the kiln.
With the cost of energy quickly rising, the need for a new rotary kiln invention is in high demand.
Thus, what is disclosed and claimed herein is a self supporting kiln insulation cover, said self supporting kiln insulation cover comprising in combination an outer layer having an inside surface; at least two modules; at least two heat dams, and, a stationary support structure.
The insulation modules are located adjacent to the outer layer, on the inside surface thereof, such that the insulation modules do not touch the kiln.
The heat dams are located adjacent to and touching the kiln, and are spaced at random, and at predetermined distances apart from each other.
The stationary support structures are located so as to support the self supporting kiln insulation cover independent of the kiln.
This invention consists of an outer supported structure floating over the kiln, supported by stationary support systems. Inside the stationary cover, insulation modules are used to keep an air gap between the insulated over and the kiln. Keeping the two apparatii from touching each other guarantees a long production life and creates a smaller chance for physical damage to occur. Air is a good insulator when it is controlled. In the instant invention, the air continues to recycle itself, flowing between the two structures. The design call for thermal dams placed strategically along the kiln at random, predetermined distances apart, specifically at transitions and other areas in need of support. The dams wear against the side of the kiln, but can be easily replaced. There is minimal contact with the kiln surface, eliminating the chance of abrasion and deformation of the insulation.
In this invention, it is best if most of the insulation is in the top and the sides of the kiln jacket, due to the fact that heat rises.
It is contemplated within the scope of this invention to use an air recycling system to preheat materials, taking hot air from in between the jacket and the actual. This is used to heat the raw mix of materials and get it ready for the kiln. This is very similar to a gas-suspension pre-heater, using cyclones to create an energy reaction in the raw mix. This essentially reduces the amount of heat that is wasted to the atmosphere and lets the kiln produce a higher output.
This creates a more energy efficient machine, but the overall process becomes more productive. In order for the kiln to operate efficiently, conditions must remain constant throughout the machine. To ensure productivity, the temperature of the material and the gas must be optimized and maintained at all times.
The instant invention is not limited by the design of the kiln and is not limited by the type of insulation that is used therein. Such insulation can be, for example, Fiberglass, glass fiber, mineral wool, foam glass, cellular glass, ceramic fiber, and polyisocyanurates, to name a few. For purposes of this invention, a combination of the insulations can be used, for example, one segment along the kiln can have ceramic insulation while the adjacent segment may have glass fiber, and so on.
Companies furnishing such materials are well-known and are, for example, Tempmat, Trymer, Hi-Therm, Saint Gobain, John's Manville, Owens Corning, Roxual, Fibrex, Pittsburg Corning, Zhejiiang Zehnshen Cold Insulation Technology, and Jiaxing Zehnhua Heat.
Turning now to
The outer covering, or shell 5, can also be observed in this Figure.
Favored metals can be, for example, Aluminum, Steel, Iron, Tin, and, Magnesium.
It should be understood that both the pin 10 and the plate 11 are shown, but this is for illustration purposes only and only one of or the other of these modes of support can be used.
For purposes of this invention, one can use the support mechanism for the insulation 6 as is shown in
It should be noted that the portion of the cross section shown in
Turning now to
Thus, there is shown a rack or frame 14 for supporting the insulation 6 around the actual kiln 15. The rack 14 consists of legs 12 that project above the bottom 16 of the kiln and which are attached to each other by cross bars 17 and 18. There is also shown braces 19 and 20 and fasteners 21 in the portions of the rack 14 where the cross bars 17 and 18 meet the legs 12, both at the top and the bottom.
Returning to
Most effective seems to be the straight rod type 23 as shown in
The heat dams 23, or 28, 29 and 30 can be randomly spaced along the outer surface 25 of the actual kiln 15 and these dams 23 completely circumferentially surround the actual kiln 15. Typically, these heat dams are spaced from 6 feet to 12 feet apart from each other, however, it is common to place them in an area that may be susceptible for losing heat, such as a transitional area of the kiln 15 and thus, they may not and are not required to have even spacing from each other.
| Number | Date | Country | |
|---|---|---|---|
| 61066251 | Feb 2008 | US |
