Air-Curtain Incinerator for Energetic Materials

1. Field of the Invention

This invention pertains to incinerators. More particularly, this invention pertains to air-curtain incinerators for burning explosive or energetic materials.

2. Description of the Prior Art.

Conventional methods of disposing of contaminated waste, obsolete, or otherwise unwanted energetic materials, such as explosives and propellants, are open-field burning or detonation. These methods are not unacceptable from the standpoint of air quality control.

The air-curtain incinerator offers the possibility of reducing objectionable air-pollutants while maintaining the desirable features of safety and low-cost which open-field burning has provided. However, the conventional air-curtain incinerator is designed for the destruction of conventional wastes such as logging slash, tree stumps, construction debris, or combustible municiple wastes. For such wastes, the incinerator is normally operated in a continuous or semi-continuous fashion with the material periodically loaded into the hot incinerator. For these operations the conventional air-curtain incinerator provides a constant air flow directed into the flame at a fixed angle. Although adequate for conventional combustibles, the conventional air-curtain incinerator lacks the flexibility that research has shown to be desirable for destroying energetic materials on a batch basis. Research has revealed that in order to achieve optimum control of emissions, provision for variation of the volume of air flow and of the direction of air flow into the fire box of the incinerator is necessary. In view of the potential hazards associated with the incineration of energetic materials, control of the air flow and air angle should be accomplished using remote control devices.

The present invention has a blower which forces air through a pipe toward the fire box of the incinerator. A movable air inlet restriction plate controls the volume of air supplied to the incinerator. Air enters the fire box of the incinerator through a manifold having a plurality of nozzles. A reflector plate is mounted on the fire box in front of the manifold nozzles so that air entering the fire box reflects from the reflector plate. The reflector plate is rotatable to allow variation of the angle at which air enters the incinerator. The invention provides means for monitoring the volume of air supplied to the fire box, the angle at which air enters the fire box, and the combustion process.

FIG. 1 is a block diagram of the invention;

FIG. 2 is a pictorial representation of the essential components of the invention; and

FIG. 3 illustrates reflection of air from the reflector plate.

Referring to FIG. 1, a blower 11 provides an air supply to a steel-lined fire box 17. An air volume control means 12, which may be an air inlet restriction plate whose position may be remotely controlled, is mounted between blower 11 and fire box 17. An air volume monitor means 13, which may be a potentiometer, is connected to air volume control means 12. Air enters fire box 17 through manifold 14; and the angle at which air enters fire box 17 is controlled by an air angle control means 15, which may be a reflector plate, mounted on fire box 17 so that air passing from manifold 14 reflects from air angle control means 15. An air angle monitor means 16, which may be a pontentiometer, is connected to air angle control means 15 for monitoring the angle at which air enters fire box 17. Smoke densities may be evaluated by a combustion monitor means 18, which may be a television system, photodiodes aimed through the smoke cloud using the sky as a reference, or by photography. Other pollutants may be sampled and analyzed by physical or chemical means. The outputs of air volume monitor means 13, air angle monitor means 16, and combustion monitor means 18 are recorded on a multi-channel recorder 19. Observation of the outputs of the various monitors during the burn allows an operator of the invention to adjust the air angle and air volume for maximum pollution abatement.

Referring to FIG. 2, structural details of the invention are illustrated. The position of restriction plate 12 is controlled by a high-torque motor 27, which may be remotely controlled, to adjust the air inlet opening to a desired size. Blower 11 supplies pressurized air to manifold 14, which has a plurality of nozzles 21 that direct air toward reflector plate 15 whose position is controlled by a motor 20.

A substance 22 to be burned is suitably placed in fire box 17. A conventional burner 23, having fuel supplied through a solenoid valve 25 and electrically ignited by an igniter 24, initiates the incineration process. The temperature of the combustion is monitored by a thermocouple 26.

Referring to FIG. 3, the angle at which air enters fire box 17 is determined by the position of reflector plate 15. The optimum angle for air to enter fire box 17 depends upon the volume and nature of the material to be incinerated. An operator of the incinerator adjusts the air volume and angle at which air enters fire box 17 to minimize the smoke density and to minimize the amount of other pollutants released by the combustion process.