FR2569826A1 - INCINERATOR-PYROLYZER - Google Patents

Abstract

1. An incinerator for incinerating refuse, comprising a combustion chamber (1) with a door (4) for charging the refuse and means for feeding primary air therein, a fume duct (7) in communication with the combustion chamber (1) and including means for preventing the passage of the dust entrained by the fumes as well as means for delivering secondary air, and a post-combustion chamber (9) connected to the combustion chamber (1) through the fume duct (7), the post-combustion chamber (9) including at least one burner (11), a chimney (13) provided at one end thereof, and nozzles (10) for tangentially feeding a tertiary combustion air flow, characterized in that the nozzles (10) are distributed along a line parallel to the major axis of the post-combustion chamber (9), and in that a further nozzle (12) is provided for feeding tertiary air in the postcombustion chamber (9), said further nozzle opening axially at the end of the post-combustion chamber (9) which is opposite to the chimney (13).

Description

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  The present invention relates to a new type of furnace for

incineration of waste.

  At present, two modes of operation are mainly

  for incineration furnaces, on the one hand at high tempera-

  with a large excess of combustion air, and on the other hand

  with a so-called pyrolitic effect, ie at a relative temperature

  low temperature and limited amount of combustion air. In the first mode, the destruction of waste is very fast and complete but at the cost of a high consumption of supplementary fuel and there are flights of dust often accompanied by

  colored fumes when destroying high PCI waste.

  In the second case, fuel consumption is

  reduced, there is little entrainment of dust and fumes are little or not colored, but the burning time is

  I5 appreciably longer and, above all, there are sometimes imbru

  due to insufficient combustion temperature.

  The present invention relates to a new type of furnace which makes it possible to obtain the advantages of the two modes of operation previously described while avoiding their disadvantages. Otherwise,

  the furnace design according to the invention allows a large modula-

  flexibility and versatility in ancillary equipment and

its implantation.

  An oven according to the invention consists of a main chamber

  said combustion chamber, of relatively large volume and

  normally lined with insulating and refractory materials,

  a waste loading door designed to prevent

  air inlets or flue gas outlets during incineration.

  Specially arranged nozzles allow the injection into this chamber of a portion of the combustion air called primary air One or more burners may be provided to initiate or maintain the combustion of waste. The shape of this chamber may be parallelepipedal or cylindrical, preferably with a large horizontal axis. The loading door being located in frontage, the exit of the fumes is done by the opposite wall in a flue of

  circular or quadrilateral section.

  In this flue or smoke duct, orifices are provided for injecting said secondary air air such that on the one hand the fumes from the combustion chamber are enriched with oxygen and on the other hand that the dust trapped

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  the fumes are forced back to the combustion chamber, for this, the secondary air is injected against the flue current the respective directions of the fumes and secondary air forming an obtuse angle between 100 and I400. The air flow, its speed and the distribution of the injection orifices being provided so that the air curtain thus created is of interest to the whole section.

of the smoke sheath.

  The smoke duct connects the combustion chamber to another so-called post-combustion chamber, cylindrical in shape and lined with insulating and refractory materials. This chamber is of large volume so that the fumes stay there long enough to be completely oxidized and decomposed. The volume is calculated so that the minimum residence time is 0.6 seconds. Sheath

  of smoke penetrates tangentially into the post-combustion chamber.

  I5 tion. One or more burners may be provided to carry or

  keep the post-combustion chamber at a sufficient temperature

  to completely oxidize the fumes, destroy all the

  fuel and crack organic molecules. This or these burners direct their flame tangentially in the post-combustion chamber. Air called tertiary air intended to bring the

  additional oxygen needed and to accentuate the

  coidal fumes is injected into the post-combustion chamber, firstly through a series of nozzles arranged along a generator, which direct this air tangentially in the chamber and secondly through a central orifice according to the main axis of the room. The air flows injected by these various orifices

being adjustable.

  The afterburner chamber connected to the combustion chamber

  It is also possible for the flue gas duct to have its main vertical, horizontal or inclined axis of any angle and this simply by pivoting with the flue gas duct with respect to the outlet orifice of the combustion chamber. The afterburner chamber is also connected to a chimney to allow

the evacuation of gases.

  The configuration of such an assembly allows the oven to function

  perfectly according to a cycle in two main phases.

  First, after the introduction of waste and ignition, while volatile and easily combustible materials are still abundant, the combustion is done with pyrolytic effect, in

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  now a relatively low temperature and injecting little combustion air, then when the combustion will tend to slow down, the furnace will go into the incineration phase at high temperature with injection of enough air to activate the combustion. Thus while benefiting from fuel savings thanks to the pyrolytic effect, we will obtain at the end of the cycle a total destruction.

  and fast of all combustible materials.

  This two-phase operation is made possible without inconvenience only by the action of the secondary air diffusers.

  I0 located in the smoke duct between the two rooms, which prevents

  dust trainings outside the combustion chamber.

  when the primary air flow rate is increased, as well as the particular design of the large-volume afterburner chamber where the fumes take a helical movement generated by the arrangement of the smoke duct, the burners and tertiary air injectors, this combination of means to maintain the fumes the time required, at the temperature

  necessary minimum and in intimate contact with the sufficient quantity

  oxygen to completely destroy combustible materials.

  The invention will be well understood thanks to the following description

  by way of example and with reference to the accompanying drawing.

  Figure I shows a longitudinal section of an incinerator

  tor, comprising a combustion chamber (I) lined with insulating and refractory materials, equipped with a burner (2) and nozzles for injecting the primary air (3). A loading door (4)

  Hermetic allows the introduction of waste into the home (5).

  The combustion fumes (6) are discharged through the smoke duct (7) into which the secondary air is injected by a series of nozzles (8) oriented so that the air jet forms an obtuse angle with the fumes. The fumes then penetrate tangentially into the post-combustion chamber (9) also

  filled with insulating and refractory materials and where the action

  joined tertiary air injected by the nozzles (IO) arranged on

  along a generator and the burner (II) whose flame is equal

  directed tangentially in the afterburner chamber,

  accentuates the circular movement of fumes, transformed into movement

  helicoidal effect by the combined effect of tertiary air injected axially through the central orifice (I2) and the draw generated by the

  chimney (I3) for evacuation of fumes.

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  FIG. 2 is a front view of the installation where the combustion chamber (I) and the loading door (4), the afterburner chamber (9) and the chimney (I3) are shown. solid lines in a vertical position and in phantom lines in a horizontal position, this position change being obtained by simply pivoting about the axis of

the smoke duct (7).

  An incineration furnace according to the invention is particularly suitable for destruction without odor, visible smoke or nuisance

  IO of all combustible waste and in particular household waste.

gers, hospitable or industrial.

Claims (5)

  I) Incineration furnace characterized in that it consists of a combustion chamber (I) of large volume provided with a loading door of the waste (4) sealingly and or is injected part of the air required for the combustion of the waste in the form of primary air U3), a smoke duct (7) opening into the wall opposite to the loading door (4) and comprising means for preventing the passage of the dusts entrained by the fumes and to provide them with additional combustion air in the form of secondary air (8), connecting the first   iO chamber to a second so-called post-combustion chamber (9) cylin-   a large volume, with means for giving the fumes a helicoidal movement and for ensuring an intimate contact   and prolonged combustible particles with oxy-   the combustion air gene in the presence of a high temperature, the waste destruction cycle taking place in two phases, a so-called pyrolytic first phase carried out at a relatively low temperature and with a primary air defect and a second phase switched on when the waste is more difficult to burn   which is carried out at high temperature and with excess primary air.   2) Incineration furnace according to claim I, characterized in that the main axis of the post-combustion chamber (9)   can be installed vertically or horizontally or inclined   born by any angle simply by rotating the assembly   post-combustion chamber (9) and fume jacket (7) by   relative to the outlet of the combustion chamber.   3) Incineration furnace according to claim I characterized by   the fact that the means intended to prevent the passage of dust   the flue gases to the afterburner chamber (9) comprise secondary air injection ports (8) in the flue gas duct (7) connecting the two chambers oriented so that the air secondary flow is injected against the current relative to the fumes, the axes of the respective currents of the air and fumes forming an obtuse angle between 100 and I400, the number and the spacing of the orifices being such that taking into account the flow and the speed of the air, the whole section of the smoke duct (7) 6 2569826   is interested in the air curtain formed.   4) incineration furnace according to claim I characterized in that the volume of the post-combustion chamber (9) is such that   the flue gas residence time is at least 0.6 seconds.   5) Incineration furnace according to claim I characterized by   the fact that the means used to give fumes   helicoidal cavity and ensure intimate and prolonged contact between   combustible particles and oxygen molecules from the air of com   It consists in penetrating the fumes tangentially to an end of the post-combustion chamber (9) by means of the connecting sheath (7) and accentuating the initial movement by also tangential injection of tertiary air by means of a series nozzles   (I0) staggered along a generator parallel to the main axis   pal of the chamber (9), while another port (I2) injects   I5 tertiary air along the main axis so as to cause the fu-   to the opposite end of the chamber and to the flue (I3), the high temperature required for the total destruction of the combustible particles being maintained by one or more tangential burners (II) also contributing to   maintain the helical movement.