FR2791087A1 - Device for suppressing flames and incandescent particles and removing toxic chemicals from exhaust gases - Google Patents

Abstract

Device for suppressing flames at an exhaust and incandescent particles and for filtering and catalyzing exhaust gases containing toxic chemicals comprising a filter and a catalyst. The filter is arranged in a battery and the gas inlet is directly into the filter assembly. The exhaust gas passes from the filter to the catalyst. The filters are regenerated by catalytic combustion of the particles using a fuel additive. The fuel additive is made at the time of the technique from ferric, cerium, copper and other bases.

Description

A The present invention relates to a device for filtering and catalyzing

  exhaust from an internal combustion engine

especially diesel.

  Usually the filter and the catalyst are two separate sets. This dissociation poses a problem of space for installation on an engine and a problem of efficiency linked to the loss of temperature of the

exhaust gas.

  In addition, all internal combustion engines, particularly diesel engines, during operation emit flaming particles and high gases.

  AO exhaust outlet temperatures.

  In the current state of the art of explosive atmosphere protections, the standards describe protections using the technique of exhaust gas temperature exchangers and cooled casings to lower the temperature of the gases, coupled with A5 stop devices flames; device stopping the propagation of a flame towards the outside by the use of a stack of sheets leaving between it a gap defined by the modes and levels of protection standardized according to the classifications, risks and modes of protection . This flame arrester due to the accumulation of soot in the interstices must be

  2LO regularly cleaned by the user.

  There is also behind the flame arrester, a spark arrester device, preventing the propagation of incandescent particles to the outside. The technique usually used in the spark arrester is a 2- centrifugation of the gases, causing the centrifugation, of the incandescent particles towards the walls of the spark arrester, the particles are braked on these walls and are stored extinguished avoiding the projection in the atmosphere which could cause an explosion or fire. The present invention aims to achieve an improvement of these devices by the use only of a device for filtering

  particles serving both as a flame arrester and as a spark arrester.

  This set is included in an exhaust gas cooling set. -2z- A The invention consists for this purpose in a device characterized in that the filtration installation is constituted by either ceramic type filters, silica carbide, ferrous or any other material which can have a filtration effect on the particles contained in the exhaust gas. The filters (1) are inserted in a chamber receiving the raw gases coming from the engine via the gas inlet (3). After passing through the filters, the filtered gases are found in the temperature exchanger (8), where the temperature level is lowered depending on the

  jo temperature classes according to the standard used.

  For example class T4, surface temperature 135 C.

  The purified gases leave without flames and without sparks by the gas outlet

  (5), the filters (1) having broken the flames and retained the particles.

  According to one embodiment of the invention, provision is made for the use of an additive in the fuel, the role of which is to allow the combustion of the particles stored at low temperature by a catalysis system. At the present time in the art, the additives are based on iron, cerium, strontium,

copper and other derivatives.

  The temperature exchanger (8), according to one embodiment, is designed as a function of the quantity of exhaust gases and their temperature in order to lower the temperature by passage (7) over finned tubes in which

  passes the engine coolant.

  In the current principle, the catalysis and filtration of particles requires temperatures above 250 C for the proper treatment of toxic gases

  2.5 and above 650 C for the combustion of soot (particles).

  The device of the invention overcomes these drawbacks. he

  comprises, in fact, several particle filters (1) arranged on the battery.

  An oxidation catalyst (2) is placed at the outlet of the filter assembly.

  The catalyst is held at the outlet of the filter assembly either by welding

  or according to a variant not illustrated by mechanical fixing.

  The exhaust gases pass from the gas inlet (3) to

  filters (1) then through the catalyst (2) to the outlet (5).

  The size of the filters and the catalyst (s) are related to the power of the engine. At the production level, the perforated tubes are welded inside an assembly receiving the exhaust gases. This set is fixed

  directly on the engine cylinder head by the fasteners (4).

  -3- A The use of a fuel additive allows combustion to start

  soot stored in the filters around 200 C.

  The invention allows a smaller footprint and compactness

  heat loss and a location closer to the gas outlet.

  This invention also makes it possible to be able to be installed on existing motors which have not been studied and designed to receive a filter and

  catalyst due to its reduced size.

  The particles and constituents contained in the exhaust gases of heat engines are extremely toxic to health and the environment. This invention allows to filter and catalyze in

  better conditions toxic products.

-4-

Claims (4)

CLAIMS:   1) Device making it possible to suppress flames at the exhaust and incandescent particles and to filter and catalyze the exhaust gases containing toxic products characterized in that it comprises a filter and a catalyst.   2) Device according to claim 1 characterized in that the filtering part is arranged in a battery 3) Device according to claim 1 characterized in that the entry of gases   is directly on the filter assembly.   4) Device according to claim2 characterized in that the passage of   exhaust gas can flow from the filter to the catalyst.   ) Device according to claim 1 characterized in that the filters are regenerated by catalytic combustion of soot with the use of a fuel additive.   6) Device according to claim 5 characterized in that the fuel additive currently consists of the technique by bases   ferric, cerium, strontium, copper and others.