FR2665749A1 - Automatic incineration furnace with continuous operation and variable capacity - Google Patents

Abstract

The invention relates to a waste incineration furnace which operates continuously. The furnace consists of a metallic hopper (5) located between two parallel vertical walls. The lorries climb the ramp (8) in order to discharge after opening of the door (6). The combustion grid (grate) (10) is modular and consists of rotary bars for blowing air and removing the cinders. The sequences of removal of residues are programmable and controlled by a robot. The addition or the withdrawal of one or more grid modules after modification of the hopper makes it possible to modify the incineration capacity of the furnace.

Description

DESCRIPTION
The present invention relates to an incineration furnace for burning various types of combustible waste. This type of waste is characterized by a lower calorific value (PCI) of more than 5,000 kJ / kg with a maximum water content of 40% by weight.

 The incineration of waste is traditionally carried out in two different ways which depend essentially on the importance of the quantity to be burned.

 For large quantities, incineration is carried out continuously in ovens of constant dimensions. This method of disposal requires regular and suitable supply of the oven which can only be obtained at the cost of intermediate storage necessitating the recovery of the waste to be burned. For reduced quantities, incineration is carried out discontinuously in ovens called auto-incinerators which operate by simply igniting the mass of waste previously accumulated in the oven.

The latter type of oven has the advantage of being direct loaded and operating alone after ignition, but with the disadvantage of having an uncontrolled combustion cycle which is unfavorable to the quality of the fumes and combustion residues produced.

 The incineration furnace according to the invention has the advantages of discontinuous operation ovens and also makes it possible to ensure combustion regulation, thanks to continuous and automatic operation adaptable to the quantity and quality of the treated waste. The accompanying drawings illustrate the invention.

 Figure 1 and Figure 2 show in section the incineration furnace according to the invention. The entire oven is located between 2 vertical parallel walls (1) about 2 meters apart and covered on their inner face with refractory bricks (2). In the lower part, a pit (3) makes it possible to contain a bucket (4) intended to recover the co-combustion residues.

 Between the two previously defined walls are installed two metal walls (5) made of folded sheets, hung on profiles, in accordance with Figure 3 and thus constitute the loading hopper of the oven.

The capacity of this hopper can be modified by simply moving the profiles and sheets forming inclined planes between the two walls.

 Lateral internal chimneys (9), intended to ensure the transfer of air in the upper part of the furnace, consist of sheets of refractory expanded metal fixed at a distance of ten centimeters from the parallel vertical walls (1).

 The upper sheet metal part closes the hopper with a loading door (6), and a duct (7) allows the smoke to be evacuated. An access ramp (8), the height of which will depend on the slope of the terrain, will allow the trucks to dump the waste directly into the oven, after opening the loading door.

 The oven comprises at the base, a combustion grate (10) constituted by rotary hollow bars, the section of which is defined in FIG. 4.

The upper part of the bar is pierced with holes allowing the blowing of air necessary for combustion, and the lower part with toothed profile is intended to grind and evacuate combustion residues.

 The combustion grate (10) defined in FIG. 5 is modular.

Each module is made up of 2 bars (11) with at one end a geared motor drive assembly (12) and at the other end an air blower (13).

 The modules thus defined are completely independent and placed head to tail one next to the other according to FIG. 5 to constitute the combustion grate. A grid can include a greater or lesser number of modules, depending on the desired hourly incineration capacity.

 A rotation of the bars in 2 directions, ensures the elimination of ashes. These rotations are performed periodically and alternately for each module, according to sequences previously defined from a programmable controller. This combustion and cleaning cycle depends on the quality of the treated waste: essentially calorific value and humidity. This information is detected and transmitted to the PLC via several temperature and hygrometry measurement points at various points in the oven.

Claims (4)

 1) Continuous waste incineration furnace with variable capacity, characterized in that it comprises a grid with rotary bars (9) with air blowing, constituted by the juxtaposition of identical and independent modules, each provided with 2 bars (11), a gear motor (12) and a fan (13).  2) Incineration oven according to claim 1, characterized in that the blowing control of the fans (13) and of rotation of the bars (10) is ensured sequentially by a programmable automaton according to the quantity and the quality waste to burn.  3) Incineration oven according to any one of the preceding claims, characterized in that the vertical envelope of the oven consists of two vertical walls (1), coated internally with refractory bricks and two metal inclined planes (5) extensible , made up of interchangeable sheets hung on profiles.  4) Incineration oven according to any one of the preceding claims, characterized by the fixing of sheets of refractory expanded metal (9) on the internal face (2) of refractory bricks of the vertical walls (1).