Claims
- 1. In a combustor having a cylindrical drum formed of water cooled pipes joined by perforated strips so as to be air porous, said drum being slowly rotated on its axis and having an upper open end of receiving burnable material and a lower end for discharging ashes or nonburnable material, the combination comprising, a windbox fitted to the lower portion of said drum for delivering air to penetrate and react with the material being burned, means for delivering air to said windbox, a valve disposed in said air delivery means and drive means connected to said valve for continually arresting and commencing air flow so that air is delivered to the drum in fluctuating pressure pulses, whereby the fluctuating pressure pulses of air enhance complete combustion of the burnable material, said valve includes a valve plate mounted in said windbox for rotation through an air blocking position and an air passing position, and said drive means includes a motor for rotating said valve plate and thereby generating said fluctuating pressure pluses.
Parent Case Info
This application is a continuation, of application Ser. No. 942,569, filed Dec. 15, 1986 now abandoned.
This invention relates generally to rotary kilns, of the kind becoming known as combustors, for burning waste, and the invention more particularly concerns supplying combustion air to such a structure.
U.S. Pat. No. 3,822,651, issued June 9, 1974, discloses an installation found especially useful for burning MSW (municipal solid waste) and at the same time generating useful steam. Burning takes place in a combustor drum consisting of a long cylindrical structure formed by water circulating pipes slowly rotating on the drum axis. The drum is inclined at a slight angle so that material to be burned which is fed into the higher end of the drum tumbles gradually toward the lower end. Air for burning is fed through holes formed between the pipes making up the cylindrical drum wall, and the air flow is controlled by ducts fitting adjacent the lower portions of the rotating drum.
Any burning reaction involves bringing combustion air into intimate contact with the material to be burned. When burning a mass of material such as MSW, it is sometimes difficult to get the air into the mass. If significant pressure is applied to the air to facilitate penetration, then the air volume and motion is not conducive to establishing the best burning conditions.
When open hearth fireplaces were commonly used for heat and cooking, a standard fireplace tool was a bellows. For reasons not too clear, using a bellows to pulse air into a fire appears to facilitate burning out of proportion to the effect of merely increasing the air supply. Perhaps the air under pressure during a pulse penetrates the material being burned, and the intervals between pulses allows the augmented air to completely participate in the burning reaction.
It is an object of the invention to provide a method and apparatus for augmenting the burning reaction in a combustor by using the apparent principle of a bellows-like action. A related object is to provide an apparatus of the foregoing kind that is simple and reliable, so as to be economical to manufacture and maintain.
US Referenced Citations (5)
Continuations (1)
|
Number |
Date |
Country |
| Parent |
942569 |
Dec 1986 |
|
Patent Grant
4784604
