WO1996015081A1

WO1996015081A1 - A process and installation for treating organic material in order to change it into mineral condition, especially for treating urban garbage

Info

Publication number: WO1996015081A1
Application number: PCT/BR1995/000050
Authority: WO
Inventors: Antonio Germano Gomes Pinto
Original assignee: Antonio Germano Gomes Pinto
Priority date: 1994-11-10
Filing date: 1995-11-09
Publication date: 1996-05-23
Also published as: AR000102A1; UY24079A1; BR9404414A; AU3899995A

Abstract

The present invention proposes the change of organic garbage into inorganic matter, which can be used as a fertilizer, in a more efficient and cost effective manner than with the known processes. This object is achieved by a process and an installation in which the organic material is first burned in a furnace (1), the gases and vapors which result from the combustion being then washed in a washer (7, 21). Both the solid residues of combustion in the furnace (1) and the washing medium which has reacted with the gases and vapors in the washer (7, 21) are conducted into a decantation reservoir (17), which can also serve as a source of washing medium for the washer (7, 21), forming a closed circuit.

Description

Specification of the Patent of Invention for: ^HA PROCESS aftND INSTALLATION FOR TREATING ORGANIC MATERIAL IN ORDER TO CHANGE IT INTO MINERAL CONDITION. ESPECIALLY FOR TREATING URBAN GAR¬ BAGE"

The present invention refers to a process and in¬ stallation for treating organic material in order to change it into mineral condition, especially for treating urban garbage. More particularly, the invention refers to a technique for ob¬ taining nutrient salts, without the need of further steps of treatment following the process, so that the final product, namely the saline mixture, can be incorporated into the soil in the form of fertilizers, rich in mineral salts.

Carbon, which is a fundamental chemical element for the survival of plants, can be absorbed by the root of the plant through microbiologic decomposition which results from burning organic matter, whereby some nutrients are formed ei¬ ther through the nutrient salts diluted in water, obtained from the microbiologic decomposition, during which said chemi¬ cal element is retained in the form of carbonates and other organic structures. The nutrient salts form a product highly rich in nitrogen, phosphorus, potassium, etc, thus being an excellent fertilizer for the soil.

The existing processes of treating urban garbage for obtaining manure to be incorporated into the soil are not ca- pable of obtaining a satisfactory percentage of mineral salts sufficient to nourish the plant. Even so, the only known al¬ ternatives to replace the nutrient salts are: the manure or humus and the residues of burning, which are cheap techniques but they are still precarious and insufficient for nourishin the plant.

In addition, the manure is basically the result o

5 mixing organic matter which serves exclusively as a carrie for transporting the nutrient salts. The production of manur is made through either aerobic or anaerobic fermentation o garbage.

There are various processes of treating urban gar

10 bage for obtaining manure for the soil, or even liquid o solid fuel. The process of transforming garbage by grinding i to bring about forced (anaerobic) fermentation is alread known from BR pat. appl. PI 67,075, which describes a proces in which one portion of the matter treated goes for the pro

15 duction of furfurol, and the other portion goes for the pro duction of wet manure, by recycling, grinding and treatin domestic garbage with a phosphoric acid solution, whereb hydrolysis takes place. This garbage is basically materia from cellulose.

20 BR pat. appl. PI 61.601 also refers to the transfor mation of domestic garbage and debris into fertilizers b grinding and fermenting the matter under controlled temper ature, in contact with an oxidizing gas, whereby th fermentation occurs naturally (aerobic fermentation).

25 In these cases, in addition to the high cost of car rying out these processes, they have various shortcoming which make their utilization infeasible, namely: pollutant due to release of methane gas into the atmosphere, which i much more harmful than carbon dioxide; slowness, since, in ad

30 dition to the time consumed in the fermentation treating, th manure, after being obtained, needs a special treatment to b applied to the soil; and the contamination of the environment which increases the risk of contaminating the populatio through pathogenic microorganisms.

35 Another conventional processing for treating urba garbage is that carried out by burning the latter for obtain *^■. ing either fuel or manure. In this process, a complete com bustion and burning of the whole matter takes place, whereb the elements and substances of the garbage are changed int residues of burning, so called basic oxides.

US pat. 5,313,894 describes an invention by which garbage is partially burned under non-oxidizing or reducing atmosphere, whereby one portion of the matter is changed into fuel, and the other portion is changed into basic oxides. This known process is carried out through an incineration struc¬ ture.

BR pat. appl. PI 8108660 discloses a device and a process of treating domestic garbage by dehydrating the or- ganic matter and the urban residues, by compressing them, and then burning the dehydrated material for releasing the combustible gases and for obtaining coke in the form of in¬ gots.

The equipment described in DE pat. appl. 42 39 305 Al also employs a process of burning urban garbage for obtain¬ ing nutrient residues for the purpose of fertilizing the soil. In spite of burning the garbage either partially or wholly, these known expensive devices and respective processes involve ecologic problems, since none of them treats the gaseous effluents from the burning before they are released into the atmosphere in the form of gases and vapors, which may cause damage to the environment.

The washing of gaseous effluents is teached, e.g., in US Pat 4,454,427, which discloses a system for washing ex- hausted gases comprising an incinerator and a fume separator, which purpose relies in generating steam from waste material. This document teaches the use of an alkaline material in wet scrubbers to neutralize the gaseous products, and suggests a fume separator which intimately mixes a pre-prepared liquid alkaline solution, such as lime water, with acidic waste fumes. This intimate mixing is obtained by the propelling action of a "ribbed slinger". The liquid alkaline solution is recycled back to a vessel, after passing the fume separator, but is filtered as to remove particulate materials. Because the primary object of this known device is to produce steam there is a certain combination of tire chips, trash and sludge powder which is preferred for excellent burning, resulting in corresponding high temperatures. The ashes removed from the furnace are carried away and can be used for land filling. Such device is of complex nature, and does not aim further use of the ashes removed from the furnace as fertilizer.

As used herein, the term "nutrient" shall be under¬ stood as meaning any mineral such as nitrates, phosphates, carbonates, chlorides, etc. capable of nourishing a plant. Besides, the term "basic oxides" or "alkalines" or "ashes" are also to be understood as meaning any residual element or sub¬ stance oxidized in the complete burning of garbage, such as sodium oxide, potassium oxide, calcium oxide, magnesium oxide, iron oxide, etc.

Summary of the Invention

The present invention provides an improved technique for transforming organic garbage into inorganic matter, which eliminates the above problems, transforming debris of organic garbage into nutrient mineral salts which can be immediately incorporated into the soil without further treatment.

The process for treating organic material, in ac¬ cordance with the present invention, comprises the steps of: a) burning the organic material by means of a source of heat in a furnace, which results in gases and vapors as well as in solids; b) extracting the gases and vapors from the furnace and leading them into a washer; c) leading the solids resulting from the burning into a decantation reservoir; d) washing the gases and vapors extracted from the furnace in the washer with a washing medium, the washing me¬ dium reacting with the gases and vapors, resulting in a re¬ acted washing medium and in washed gases and vapors; e) releasing the washed gases and vapors; and f) leading the reacted washing medium into the decantation reservoir.

In a preferred embodiment, the above steps are car¬ ried out continuously and simultaneously and partially in closed circuit. Preferably also the washing medium which washes the gases and vapors in the washer is extracted by pumping from the decantation reservoir and introduced into the washer through several inlets. According to an advantageous embodiment, the extraction of the gases and vapors from the furnace is carried out by means of a system of rotating propellers disposed within the washer, said system also pro¬ viding the mixing of the washing medium with the gases and va¬ pors coming from the furnace. In a possible embodiment, the washing of the gases and vapors coming from the furnace is carried out in two or more washers connected to each other in series, the release of the gases and vapors into the atmos¬ phere taking place at the outlet of the second or last washer, respectively. As to the material deposited continuously into the decantation reservoir, the process of the invention may in¬ clude the step of draining the decantation reservoir, and then drying the residues drained out of the decantation reservoir, which can be subsequently improved, for instance by grinding and milling.

The installation in accordance with he present in¬ vention comprises, in combination:

- a furnace comprising an opening for feeding or¬ ganic material to be treated, an enclosure suitable for re- ceiving a volume of organic material, a source of heat provided at least close to a lower end of the enclosure for burning organic material, an outlet for solid residues of com¬ bustion at least close to said lower end of the room and an outlet for gases and vapors; - a first conducting means connected to the furnace for passage of the gases and vapors generated by the burning of the organic material inside the furnace;

- a suction means for suction of the gases and va¬ pors out of the furnace through the first conducting means; - at least one gas and vapor washer connected to the furnace through the conductirq means, comprising an inlet for gases and vapors, to which the first conducting means is con¬ nected, an inlet for washing medium, an outlet for gases and vapors and an outlet for washing medium; - a decantation reservoir;

- a second conducting means being provided, which interconnects the lower end of the furnace and the decantation reservoir, as well as a third conducting means, which inter¬ connects the washer and the decantation reservoir. Preferably, a mixing means is provided inside said washer. By mixing means it is to be understood any means which provides an adequate mixing of the washing medium with the gases and vapors, including dynamic mixers with rotating blades or propellers, or static mixers with exchanging filler- columns and bafflers for prolonging the passage inside the washer. Provided that the washing liquid is injected at a suf¬ ficient high pressure and with sufficient distribution in the washer, no separated mixing means is necessary. According to a preferred embodiment, the suction means consists of a set of rotating propellers provided inside the washer, which acts simultaneously as a mixer of the wash¬ ing medium and the gases and vapors. The sets of propellers are mounted equidistantly on an axle driven, for instance, by an electric motor. Alternatively, however, the suction means may consist of a vane or air pump provided within the first conducting means. Since the gases and vapors are sucked, the outlet for gases and vapors may be provided in the furnace also close to the lower end, but it is preferably foreseen close to the upper end.

According to another preferred embodiment, in which the washing medium circulates in a closed circuit, a pump is provided for pumping liquid contained in the decantation res¬ ervoir into the washer through the inlet for washing medium. According to a further preferred embodiment, the washer is provided with several inlets for receiving washing medium.

In order to increase the efficiency of washing of the gases and vapors, a second washer can be provided, con- nected to the first one in series. In this way, an improve¬ ment in quality of the washing of the gases and vapors will be guaranteed, thus decreasing the amount of carbon dioxide re¬ leased into the atmosphere and minimizing the risks caused by the polluting gases in the environment, besides raising the rate of carbonate concentration in the nutrient salts. The second washer also comprises an inlet and an outlet for gases and vapors, as well as an inlet and an outlet for washing me¬ dium, the outlet for gases and vapors of the first washer be¬ ing connected to the inlet for gases and vapors of the second washer. In the embodiment where the installation comprises a single washer, its outlet for gases and vapors leads into the atmosphere through an exhausting duct, whereas in the embod¬ iment having two or more washers the outlet into the atmos- phere takes place in the second or last washer, respectively. In order to prevent, as much as possible, solid par¬ ticles from entering the washer, the first conducting medium may be provided with a filter. Yet, a known type soot or ash trap can be foreseen at the exit of the furnace to collect part of the ash that is carried out of the furnace together with the combustion gases.

In another preferred embodiment, the furnace and the washer of the installation in accordance with the invention have an internally cylindrical, vertical shape, the furnace being provided, in the lower portion of its side wall, with an opening for entry of the heat source and air, and with ar out¬ let for the residues of combustion.

For the operation of the process and installation in accordance with the invention, in an example of embodiment, the material to be treated is loaded through an upper opening of the furnace, either by means of conveyors or directly from dump trucks. Following this step, a blow torch serving as a source of heat and provided at the lower portion of the wall of the furnace is ignited, whereby the burning of the garbage begins. Simultaneously the water pump is actuated, for pump¬ ing pure water or an alkaline mixture from the decantation reservoir into the washer, together with the electric motor which drives the mixer/exhauster existing inside the washer.

From this step on, the burning of organic or inor- ganic elements of the garbage will take place in an acceler¬ ated way until they are completely burned, reducing the fina?. residue to ash by calcination. The accelerated effect of burn¬ ing the garbage is helped by the oxidizing atmosphere brought about by forced suction of the gases and vapors. Simultaneously, in a first cycle, water is shed into the washer and falls onto the moving propellers of the mixer/exhauster under pressure, being violently scattered, where, in contact with the volatile components (gases and va¬ pors), it will react with them, forming a liquid mixture with volatile components rich in oxiacids, thus causing the gases and vapors to be washed. After having been washed and puri¬ fied, the gases and vapors, predominantly carbon dioxide and water vapor which did not react in contact with the water, will be launched into the atmosphere through an opening in the upper portion of the washer, connected to a duct which leads into the atmosphere.

The liquid mixture is conducted by gravity to an outlet provided at the lower portion of the washer, where it will be collected through a duct. In conjunction with this op¬ eration, the ashes resulting from the burning, due to the pressure exerted by the mass of garbage onto them, will na¬ turally be discharged through a grid existing at the lower opening of the furnace, where, by gravity, the ashes will be carried by a duct made by masonry and which leads into the decantation reservoir. Alternatively, the decantation reser¬ voir may be provided immediately below the furnace and/or the washer.

When the liquid mixture leaving the washer meets the ashes from the furnace, be it on the way to the decantation reservoir or inside the reservoir itself, they will combine and react chemically, producing a basic solution rich in min¬ eral salts, with the consequent neutralization and transforma¬ tion of the garbage into inorganic matter. This is therefore a classic chemical reaction of the acid-base type, resulting in salt and water, with a slightly basic final mixture, due to the loss of carbon dioxide into the atmosphere. If necessary, the pH of the mixture will be adjusted so that the mixture will be maintained alkaline for greater efficiency of the process. Through the decantation process, the residues (min¬ eral salts, ashes, residues of carbon, etc.) are deposited onto the bottom of the reservoir.

In the next cycle of the process, it is no longer pure water that will be pumped into the washer, but rather a basic saline solution coming from the decantation process which took place in the reservoir, as a result of the ashes that have been carried to the reservoir on the preceding cy¬ cle. Preferably this cycle between reservoir and washer and back to the reservoir is performed by the washing liquid in closed circuit. The more frequently this cycle occurs, conse¬ quently making the basic alkaline solution more used, the greater the capacity of reactivity of said solution with the gases and vapors, due to the even greater predominance of alkalinity over acidity of the mixture.

Since this is a cyclic, automatic and continuous op¬ eration, there will be a moment of saturation of residues in the reservoir, the amount of residues deposited into the res¬ ervoir becoming virtually equal to the volume of the latter. At this moment this material in the form of mud should be dredged, undergoing a process of natural drying, becoming a solid mass, which in turn will finally undergo a process of grinding and milling, so that it can be commercialized.

By the use of the present invention, the problems associated with the earlier equipment are overcome. The in¬ stallation in accordance with the invention provides various advantages such as: it changes the organic garbage into inor¬ ganic material rich in nutrient salts, which can be directly incorporated into the soil as a fertilizer with properties ca- pable of correcting the pH of the soil, thus replacing the calcareous rocks with a reduced cost for both the mounting of the installation and the processing of the garbage; it elimi¬ nates the sanitary embankments and garbage dumps; it signif¬ icantly reduces the initial volume of garbage after its processing, which can reach a final volume of ashes and nutri¬ ent salts of about 5% of the initial volume; it disinfects the environment, reducing the risks of contaminating the popu¬ lation through pathogenic microorganisms, due to the absence of contamination of the underground water and of the environ- ent; it avoids polluting the atmosphere by eliminating the polluting gases which come from sanitary embankments by the action of the anaerobic bacteria; in a simpler way, it reduces the production of carbon dioxide launched into the atmosphere, by virtue of the washing of the gases and vapors in the wash- ers; it optimizes and renders the treatment of garbage sani¬ tary; and it makes the utilization of the nutrient salts resulting from the proposed process of treatment more econom¬ ical.

The invention will now be described in greater de- tail on the basis of exemplifying embodiments with referenc to the accompanying drawings. Brief Description of the Drawings

- figure 1 is a schematic side view of the installa 5 tion comprising a furnace, a gas-and-vapor washer and decantation reservoir; it also shows the flow of substanc processing; and

- figure 2 is a schematic side view of the installa tion showing the new flow of substance processing using mor

10 than one gas-and-vapor washer.

According to figure 1, the installation includes, i sequence: a forced-suction furnace 1, internally cylindrica and vertical and having dimensions proportional to its burnin capacity, the furnace 1 being interconnected by a suction duc

15 5 to a gas-and-vapor washer 7, constituted by an internall cylindrical reservoir and positioned vertically; and, finally, a decantation reservoir 17 on a plane below the furnace an the washer, which may be either a natural lake or an artifi cial reservoir. In said installation ducts are provided for

20 carrying the products of said process, disposed between th furnace 1, the gas-and-vapor washer 7 and the decantation res ervoir 17. Although the example given indicates the provisio of separate ducts for leading the solid residues from the fur nace and for the reacted liquid medium which leaves the washe

25 into the decantation reservoir, both may be conducted by common duct.

Since the furnace 1 is already known from the prior art, there is no need for describing it in detail; however, for a better understanding of the preferred embodiment, a fe

30 functional details of the furnace 1 are described.

The furnace 1 comprises an opening la for feeding garbage and a room lb suitable for holding a volume of gar bage. At the bottom of the furnace 1, which is funnel-shaped, an outlet 2 for residues is provided, on which a grid 3 is

35 placed. At the lower portion of the side wall of the furnace 1 an opening 4 is provided, where the heat source and a thermal

_* sensor for controlling the temperature in the furnace are in

^Λ stalled. The heat source may be a gas or liquid-fuel flowtorch or any other suitable source capable of supplying adequate heat for the process.

The suction duct 5 is defined by a preferably cylin¬ drical duct made in masonry and of a refractory material, hav¬ ing an inner coating of metal blade or any other refractory synthetic material configured so that one end 28 of the duct will be disposed at the upper portion of the furnace 1, and the other end 29 will be connected to an inlet 8 at the lower portion of the side wall of the washer 7.

In order to minimize the trailing of solid particles resulting from the combustion in the furnace into the washer 7, caused by the suction existing in the duct 5, a filter 6 is provided close to the end 28 of the duct 5.

In addition, the suction duct 5 may be designed with a length and a shape suitable for promoting cooling of the gases and vapors sucked from said furnace 1, in order to pre¬ vent the high temperature of the gases from impairing the op¬ eration of the washer 7. E.g., although not shown, it is possible to foresee a jacket around the suction duct and to cause the washing liquid to pass through such a jacket before it is introduced into the washer, thus providing heat exchange between the gases and vapors and said liquid.

The means for carrying the residues of combustion of the garbage is defined by a cylindrical duct 9, preferably constituted by masonry, one end of which is connected to the opening 2 at the bottom of the furnace 1, and the other end 14 of which discharges at the edge of the decantation reservoir 17. The liquid which leaves the washer 7 comes out through an opening 11 and can be conducted by a duct 10 directly into the decantation reservoir 17, or else the duct 10 may be connected to the duct 9 immediately below the washer or at any other point, whereby the liquid becomes mixed with the residues of combustion before reaching the reservoir.

A rigid cylindrical duct 15, e.g. of a plastic mate¬ rial, interconnects the decantation reservoir 17 and the washer 7. The duct 15 has an end 16 inside the reservoir 17, and other ends connected to openings 18, provided at various points of the washer. Somewhere along the duct 15 a hydraulic pump 31 is provided for pumping liquid from the reservoir to the washer. Alternatively, the washing liquid may be water from the public network.

The gas-and-vapor washer 7 has a mixer/exhauster 1 inside it, which comprises a rigid, elongated rotating axl provided with propellers 13 disposed equidistantly one fro another, where said axle is connected through its ends 26 an 27 to the center of the upper and lower parts of said washe 7, the connection of the first end 26 being effected at a ro tating driving mechanism (not shown), and the second end 2 being connected at a rotating device (not shown). At the uppe portion of the washer 7, an exhausting duct 19 is provided, e.g. made of synthetic material, connected to a passage open ing 20 for discharge of the washed gases containing carbo dioxide and water vapor into the atmosphere.

According to another embodiment of the invention il lustrated in figure 2 , a second gas-and-vapor washer 21 i provided between the first washer 7 and the decantation reser¬ voir 17, which washer 21 is connected in series to the first washer 7, having the same configuration and installation fea¬ tures of the latter. According to this embodiment, a duct 22, e.g. of a synthetic material, is provided, which intercon¬ nects the two washers 7 and 21, one end of which is connected to the opening 20 in the upper portion of the first washer 7, and the other end of which is connected to the opening 23, provided in the lower portion of the side wall of the second washer 21. An opening 24 for release of washed gases and va¬ pors into the atmosphere is then provided at the upper portion of the second washer 21, a duct 25 being connected to said opening 24.

The exit of the washing liquid from the washer 21 takes place through a duct 30, which is connected to the duct 10 coming out of the first washer 7.

The proposed installation is inexpensive and easy to manufacture, while being also adaptable for the processing of all kinds of urban garbage. The installation does not require complex parts and interconnections between them, thus having a simple and fast maintenance, thereby minimizing the standstill time at said installation for effecting the service.

Although the invention has been described on the ba¬ sis of examples of embodiments represented in the drawings, it should be understood that various alterations can be made without departing from the spirit and scope of the invention, defined in the claims.

Claims

1- A process of treating organic material in order to change it into a mineral condition, especially for treating urban garbage, characterized by the steps of: a) burning the organic material through a source of heat in a furnace, which results in gases and vapors as well as solids; b) extracting the gases and vapors from the furnace and leading them into a washer; c) leading the solids resulting from the burning into a decantation reservoir; d) washing the gases and vapors extracted from the furnace in the wasner with a washing medium, the washing me¬ dium reacting with the gases and vapors, resulting in a re- acted washing medium and in washed gases and vapors; e) releasing the washed gases and vapors; and f) leading the reacted washing medium into the decantation reservoir.

2- A process in accordance with claim 1, character- ized in that the steps of the process are carried out contin¬ uously and simultaneously.

3- A process in accordance with claim 1, character¬ ized in that the washing medium which washes the gases and va¬ pors in the washer is extracted out of the decantation reservoir by pumping and is conducted into the washer by se¬ veral inlets.

4- A process in accordance with claim 1, character¬ ized in that the extraction of the gases and vapors from the furnace is carried out by means of a system of rotating propellers inside the washer, said system also promoting the mixing between the washing medium and the gases and vapors which come from the furnace.

5- A process in accordance with claim 1, character¬ ized in that the washing of the gases and vapors from the fur- nace is carried out in two or more washers connected to each other in series, the release of the washed gases and vapors into the atmosphere taking place at the outlet of the second or last washer, respectively.

6- A process in accordance with claim 1, character- ized by including the step of draining the residues out of the decantation reservoir and then drying them.

7- A process in accordance with claim 6, character¬ ized by including the step of improving said residues. 8- A process in accordance with claim 7, character¬ ized in that the step of improving the residues includes grinding and milling them.

9- An installation for the treatment of organic ma¬ terial in order to change it into the mineral condition, espe- cially for che treatment of urban garbage, characterized by comprising, in combination:

- a furnace (1) comprising an opening (la) for feed¬ ing organic material to be treated, a room (lb) suitable for receiving a volume of organic material, a source of heat (4) provided at least close to a lower end of the room (lb) for burning the organic material, an outlet (2) for solid residues of combustion at least close to said lower end of the room (lb) and an outlet (28) for gases and vapors;

- a first conducting means (5) connected to the fur- nace (1) for passage of the gases and vapors generated by the burning of the organic material inside the furnace; a suction means (12, 13) for suction of the gases and vapors out of the furnace (1) through the first conducting means (5); - a gas-and-vapor washer (7) connected to the fur¬ nace (1) through the conducting means (5), comprising an inlet (8) for gases and vapors, to which the first conducting means (5) is connected, an inlet (18) for washing medium, an outlet (20) for gases and vapors and an outlet (11) for washing me- dium;

- a decantation reservoir (17);

- a second conducting means (9) being provided, which interconnects the lower end of the furnace (1) and the decantation reservoir (17), as well as a third conducting means (15), which interconnects the washer (7) and the decantation reservoir (17).

10- An installation in accordance with claim 9, characterized in that the furnace (1) and the washer (7) have a vertical cylindrical inner shape, the furnace being funnel- shaped at its base.

11- An installation in accordance with claim 9 characterized in that a mixing means (12) is provided insid the washer (7). 12- Installation in accordance with claim 11, char acterized in that the suction means (12, 13) consists of a se of rotating propellers (13) provided inside the washer (7) which simultaneously actuates as a mixer for the washing me dium and the gases and vapors. 13- An installation in accordance with claim 9 characterized in that the suction means consists of a vane o air pump provided in the first conducting means.

14- Installation in accordance with claim 9, charac terized by comprising a pump (31) for pumping washing mediu contained in the decantation reservoir (17) into the washe (7) through the inlet for the washing medium (18).

15- An installation in accordance with claim 14 characterized in that the washer (7) is provided with severa inlets for entry of the washing medium. 16- An installation in accordance with claim 9 characterized by comprising a second washer (21) connected i series to a first washer (7) and comprising an inlet (23) fo gases and vapors, an outlet (24) for washed gases and vapor into the atmosphere through a duct (25), an inlet for washin medium and an outlet for washing medium, an outlet (20) fo gases and vapors of the first washer (7) being connected t the inlet (23) for gases and vapors of the second washer (21)

17- An installation in accordance with claim 9 characterized by comprising a single washer (7), the outle (20) for gases and vapors of which leads into the atmospher through an exhausting duct (19).

18- An installation in accordance with claim 9 characterized in that the first conducting means (5) is pro vided with a filter (6) for retaining solid particles.