US3757706A

US3757706A - Method and apparatus for incinerating polluted liquids and mud

Info

Publication number: US3757706A
Authority: US
Inventors: J Pariel; G Robic
Original assignee: Elf Union; Heurtey SA
Current assignee: Elf Union; Heurtey SA
Priority date: 1970-04-20
Filing date: 1971-04-12
Publication date: 1973-09-11
Anticipated expiration: 1990-09-11
Also published as: NL7105233A; FR2088628A5; NO131007B; CH531681A; NL164947C; ES390378A1; NL164947B; BE765524A; NO131007C; DE2118073A1; DE2118073C3; GB1349684A; DE2118073B2; JPS5024789B1; CA940379A

Abstract

A method and apparatus for incinerating polluted liquids and mud, into which are sprayed, in the presence of an oxidizer and inside a reaction chamber, a mixture formed by the mutual dispersion of non-miscible phases at least one of which contains polluting agents to be destroyed and at least one of which is liquid.

Description

Wit

Pariei et a1.

[451 Sept. 11,1973

METHOD AND APPARATUS FOR INCINERATING POLLUTED LIQUIDS AND MUD Inventors: Jean Marie Pariel, Saint-Germain- En-Laye; Gabriel Robic, Paris, both of France Assignee: Soeiete Anonyme Heurtey and Elf- 7 Union, Paris, France Filed: Apr. 12, 1971 Appl. No.: 133,267

Foreign Application Priority Data Apr. 20, 1970 France 7014159 U.S.. Cl 110/7 S, 110/28 R, 431/115 Int. Cl. F23g' 7/00 Field 01 Search 431/115; 110/7 R,

110/7 S, 8 R, 28 R [56] References Cited UNITED STATES PATENTS 3,357,375 12/1967 Brophy 110/7 3,456,603 7/1969 Studler 110/28 3,485,566 12/1967 Schoppe 431 115 x 3,395,654 8/1968 Weisberg et al 110/28 X Primary ExaminerKenneth W. Sprague Attorney-Richard Low and Murray Schaffer [57] ABSTRACT 11 Claims, 4 Drawing Figures Patented Sept. 11, 1973 2 Sheets-Sheet 1 JEAN Mame 'PflmeL G-fifiRIEL Roblc,

Patented Sept. 11, 1973 3,757,706

2 Sheets-Sheet 2 JEAA) MARIE ?F}RI9L CHER 16L Rafi lc.

m/eunns vW m METHOD AND APPARATUS FOR IN ClNERATING POLLUTED LIQUIDS AND MUD The technical province of this invention is that of furnaces and ancillary installations, and more particularly that of combustion apparatus.

Already known are methods for ensuring the total combustion of muds by a treatment in fluidized layers, whereby mud particles to be destroyed are retained in the midst of a layer formed of granules of an inert solid. The mud particle retention time is determined so that the drying and subsequent calcination of the solids forming the mud are carried to an adequate stage.

These methods and the apparatus for performing them require a layer of considerable volume in conjunction with the use of equipment which is bulky and costly to install and operate for supplying the incinerator with the fluidizing air and the atmosphere, which must normally be an oxidizing one.

In another well-known method, the liquid to be destroyed is supplied directly into a burner flame, but this precludes a uniform temperature throughout the liquid, as a result of which the obtainment of the required temperature within the liquid, for destruction thereof, is by no means certain.

The present invention has for its object to overcome these drawbacks in prior art systems by permitting total and direct incineration of polluted liquids and muds.

It accordingly provides a treatment method characterized by the fact of atomizing, in the presence of air, and into a reaction chamber, a mixture formed for example of a dispersion of a generally polluted liquid into a further phase consisting of a liquid or gaseous product, at least one of the dispersion agents being a combustible substance.

One of these dispersion agents may contain polluting material in suspension, and more particularly solid materials and may possibly form a mud.

In most cases, though it may also contain polluting agents, the constituent which is the liquid or gaseous fuel is designed to cause the dispersion of a slightly combustible or non-combustible polluted liquid.

However, the substance to be destroyed may alternatively be formed by the combustible part of the mixture and, if it is a substance very avid of oxygen, it is preferable to place it in the presence of another phase advantageously consisting of a liquid such as water, which in that case may perform the function of an oxidation reaction moderator designed to avoid the formation of explosive mixtures with the combustion-supporting oxygen.

The mixture obtained must invariably have a heating value sufficient to enable the required temperatures 'to be obtained in the reaction chamber. Such a mixture may be obtained by any convenient means. This mixture is sprayed into the reaction chamber and mixed with an oxidizer such as atmospheric air. Any type of burner suitable for effecting these operations can be used for performing the above method, and it is preferable to select a burner that is capable on its own of effecting the mixing operations and of atomizing the mixture.

In the event that the matter in suspension contained in the liquid or liquids to be destroyed is of a size detrimental to satisfactory operation of the burner in particular, filtering means, or crushing means, or both, are provided ahead of the burner.

The result of pulverizing such a pseudohomogeneous reaction mixture that is in a state close to the colloidal state is the formation of a very large number of reaction media which associate, on the infinitesimal level, the combustible particles, the particles to be destroyed and the oxidizer, thereby permitting inexpensive oxidation of the polluting agents.

Indeed it is necessary that the consumption of combustible substances, generally consisting of hydrocarbons, be as small as possible and that reaction develop at a uniform temperature which is the lowest possible consistent with the required destruction, it being necessary for the latter to be fully completed before discharge of the smokes, and this in turn implies satisfying two major requirements, to wit, the obtainment of this very large number of reaction media and the utilization of a chamber specifically suited to a correct development of the gasification and oxidation of the substances.

One exemplary way of performing the subject method of this invention includes the following steps Filtering, possibly crushing (or both) of the matter in suspension in the fluid or fluids to be treated.

Producing a pseudo-homogeneous mixture in a state close to the colloidal state by dispersing a polluted or non-polluted liquid phase, which may be combustible or not, through another combustible or noncombustible liquid or gaseous phase which may be polluted or not.

Injecting this mixture into a reaction chamber in the presence of an oxidizer in the form of an atomized mist.

Gradual gasification of the liquids into a gaseous mass which fills the chamber completely in a combined gasification and combustion reaction the temperature of this chamber must be such as to permit vaporization of non-combustible parts in the form of droplets or particles, thereby causing the combustible corpuscles contained therein to burst and produce a very effective post-pulverization which assists the required reactions because combustion of the combustible corpuscles takes place in this way in the midst of these substance to be destroyed in the process of vaporization, and the heat released is transmitted therein infinitesimally, thereby inducing the sustained gasification process.

Homogenization of the gaseous mass, achieved thanks to recirculation motions produced in the chamber and causing gas to be recycled towards the injection orifice the recirculation is so devised that some of the gases undergoing reaction hug the walls and cause the latter to be raised to a temperature close to that of the gaseous mass, so that any still nondissociated droplets impinging upon the walls can, by virtue of the size of the chamber, benefit from a heat input that assists their entry into a mixed gasification and combustion reaction.

Thermal equilibrium in the reaction chamber is obtained by regulating the proportion of combustible substances contained in the mixture.

The present invention further relates to apparatus for performing the above-disclosed method.

The performance of this method and the use of said apparatus permit economical destruction of polluting agents.

The description which follows with reference to the accompanying non-limitative exemplary drawings will give a clear understanding of how the invention can be carried into practice.

In the drawings FIGS. 1 to 3 are schematic sectional showings of three possible embodiments of combustion chambers and FIG. 4 is a schematic perspective showing of a set of multiple chambers.

The exemplary polluting agent destroying combustion chamber shown in FIG. 1 is associated, at its inlet side, to apparatus 1 for producing a pseudohomogeneous mixture of two non-miscible phases entering through conduits la and 1b provided wtih valves 1c and 1d for regulating the quantity of combustible substances in relation to other non-combustible or slightly combustible substances, in order to obtain the required temperature in the reaction chamber to be described hereinafter. This apparatus may itself be preceded by crushing and/or screening means designed to reduce any solid matter passing therethrough to the required size.

Joined to apparatus 1 is a pulverizing system 2 which, in the event that pulverization is obtained by pneumatic means, comprises a pulverizing air inlet 2a and, in order to permit combustion, an inlet 2b for an oxidizer such as atmospheric air.

It should be noted that the mixing apparatus 1 and the pulverization and combustion system 2 can be associated with advantage to form a burner of a kind well known per se capable of effecting at one mixing, pulverization and combustion initiation.

The pulverization and combustion system in mounted in the front face of a reaction chamber 3 which is so devised as to cause a partial downstream-toupstream backflow of gaseous substances.

To this end chamber 3 includes a cylindrical portion 4 the length and diameter of which lie in the ratio of at least 3:1, preferably between 3:1 and 4:1 and with advantage between 13:4 and 15:4.

This cylindrical portion 4 is connected to a downstream convergent section 5 the apex half-angle of which lies between 18 and 22. This convergent section is succeeded by a cylindrical throat 6 provided with a partly obturating element 7 formed by a sliding plate which can be inserted to an adjustable extent into throat 6 and acts as a regulator of the negative pressure prevailing in the chamber, it being possible for such an element 7 to be positioned further downstream along the path of the smokes.

The injector-forming pulverization system is supported by the front face 8 within a refractory temperature-sustaining block 9 provided in said face, the internal profiling of said block enabling the flow characteristics at the entry of chamber 3 to be matched to the required recirculation.

The internal wall of the chamber is provided with a lining of refractory material 10 surrounded by a heat insulating liner 11, thereby to conserve an internal wall temperature close to that prevailing in the body of gas in reaction while at the same time maintaining the temperature of a metal jacket 12 above the dew-point of the injected liquids. To this end jacket 12 may be further surrounded by a heat insulating layer 13. All these linings or layers surround the chamber, convergent section 5 and throat 6.

This reaction chamber proper can be completed by an expansion chamber 14 in which the smokes are suitably cooled and rid of part of the dust they entrain in a first dust collector 14a provided with a dust extraction lock 14b, provision being furthermore made at the exit end of chamber 14 for dust discharging and final trapping means (not shown), as well known per se.

As shown in FIG. 2, chamber 3a may include a conical wall 15 which converges from end-section 8a toward cylindrical throat 6a, the ratio of the length of this conical chamber to its inlet section diameter being chosen equal to at least 3:1. The remaining arrangements in respect of such a conical chamber are identical to those in FIG. 1.

In the embodiment shown in FIG. 3, the configuration of chamber 3b is such that it includes, starting from the inlet side, a conical wall which is succeeded by a cylindrical portion 4a and thereafter by a convergent section 5a and a cylindrical throat 6b, the dimensional requirements for the length of the chamber in relation to the diameter of its inlet section and for the apex halfangle of the convergent section remaining identical. In the case of the embodiment shown in FIG. 3, the same arrangements as for that in FIG. 1 are retained on both the inlet and discharge sides.

By way of a susidiary provision, it is possible to increase the area of the internal wall of the chamber in order to intensify the reactions in contact with it. Thus instead of being smooth, said wall could be provided with a broken surface such as by forming channels in the refractory material or by providing upstanding refractory stubs thereon, which may be fitted or not, or by providing similar means.

It is further possible to provide, in such a chamber, means (not shown) for injecting a complementary mixture in a counterstream direction.

In all the above-described chambers a central flux is surrounded by an annular vortex which is carried along by the central flux and causes a recirculating current to travel along the wall in an upstream direction. This results in the internal wall being uniformly heated to the same temperature as the reacting medium, coupled with an active swirling of the atmosphere, a centrifugal projecting of any droplets still subsisting against the hot wall and, more generally, the achieving of a very active reaction for the minimum temperature consistent with destruction of the polluting agents.

The existence of such an annular vortex can be taken advantage of to effect at least one complementary counterstreamed injection immediately downstream of the annular recirculation vortex, and it is possible to introduce in such injection various substances which might be incompatible with those forming the main intake mixture.

Further, such complementary injection enables the constituents thereof to be raised to the reaction temperature more rapidly than those participating in the principal injection.

In all cases, it is possible to introduce into mixing system l a fuel-forming liquid or gaseous hydrocarbon, air and an aqueous substance, either a solution or mud, and to fetch them jointly into a state of extreme division in all cases, again, these must be substances forming at least two non-miscible phases.

One of the two phases may be the one charged with the polluting substances to be destroyed. If this phase is the fuel, the other may consist of sufficiently pure wateror some other liquid used as a moderator independently of its mixing action.

In the event that the ratio of the volume of the chamber to the active wall area thereof were to result in proand taken in the region of 2:1. These several cells debouch into a main chamber 16 shown in dot-dash lines, in which homogenization takes place. Main chamber 16 terminates in a convergent section 17, as is also the case for each of the above-described individual chambers, said convergent section 17 having an apex half-angle lying between 18 and 22 and being extended by a cylindrical throat 18 provided with an obturating element (not shown) similar to obturator 7 but applying to all the cells 3c whereby to cause the required recycling to take place. Similar feed arrangements may be retained for all the burners of cells 3c or for said burners individually.

Obviously, throat 18 is succeeded by an expansion chamber, and identical downstream installations are provided, suitably scaled to suit the flow resulting from the above arrangement of coupled burners.

It goes without saying that changes may be made in the various steps involved in the subject method of this invention and to the forms of embodiment of the apparatus hereinbefore described, without departing from the scope of the invention. By way of example, one of the mixture constituents may include variously combined or assembled gaseous, liquid or solid substances. Muds are examples thereof, though dry solids in gases can be subjected to the above-disclosed methods of destroying polluting agents.

What is claimed is:

l. A method of destroying polluting agents contained in liquids or mude comprising the steps of producing a pseudo-homogeneous mixture in a state of fine division through the mutual dispersion of non-miscible phases of which at least one phase is polluted and at least one phase is combustible, pulverizing the mixture in a reaction chamber, gasifying and burning the pulverized misture in the reaction chamber, and recirculating the gaseous substances developed in said chamber in an annular vortex from the center line centrifugally towards the downstream region of said chamber in contact with the walls thereof and centrifugally from the walls to the center line of said chamber adjacent the zone of entry thereinto.

2. A method according to claim 1, wherein at least one liquid phase is formed by a polluted substance which is only slightly or non-combustible, and at least one other phase may be liquid or gaseous and polluted or non-polluted.

3. A method according to claim 1, wherein an oxygen-avid combustible polluted phase is mixed with a preferably neutral non-polluted liquid phase which acts as a reaction moderator while retaining its mixing action.

4. Apparatus for destroying polluting agents contained in liquids or muds comprising in combination mixing means for dispersing at least one liquid phase through at least one combustible phase and wherein at least one of said phases contains polluting agents, and producing a pseudo-homogeneous mixture, pulverizing means located downstream from said mixing means for forming a very large number of reaction media particles and enhance oxidation thereof, a recirculation type reaction chamber located downstream from said pulverizing means and an expansion chamber located beyond said reaction chamber.

5. Apparatus according to claim 12 wherein the reaction chamber wall includes a cylindrical portion the ratio of the length to the diameter of which is included substantially between 3:1 and 4:1, a convergent section having an apex half-angle of approximately 22, and a cylindrical outlet throat provided with a downstream partial throttling element.

6. Apparatus according to claim 12 wherein the reaction chamber comprises a wall which includes a conical convergent section the ratio of the length to inletsection diameter of which is at least 3:1 said conical convergent section being followed by a cylindrical wall provided with a partial throttling element.

7. Apparatus according to claim 12 wherein the reaction chamber comprises a wall including an inlet section and which wall combines an initial conical convergent section with a cylindrical section downstream thereof, the combined conical section and cylindrical section having an overall length at least three times as great as the diameter of the inlet section, said cylindrical section being followed by a convergent section, the apex half-angle of which is between T8 and 22, and which convergent section is in turn followed by a cylindrical throat provided with a partial throttling element.

8. Apparatus according to claim 12 wherein the area of the internal reaction chamber wall is increased by channels and refractory studs located thereon.

9. Apparatus according to claim 12 including means located on said reaction chamber for injecting a complementary mixture in a counterstream direction.

10. Apparatus according to claim 8, wherein the complementary injection is effected through the reaction chamber wall downstream of the place of generation of an annular vortex.

11. Apparatus according to claim 12 wherein the reaction chamber is multicellular and formed by a plurality of individual chambers .open at their outlet ends and the lengths of which are equal to at least twice their diameters, said plurality of chambers being disposed within and opening into a main homogenization chamber which may be cylindrical, conical or conical and cylindrical and which terminates in a convergent section having an apex half-angle of approximately 22, which convergent section is in turn followed by a cylindrical throat provided with partial throttling means and opening into an expansion chamber.

t '0 k 4 I?

Claims

1. A method of destroying polluting agents contained in liquids or mude comprising the steps of producing a pseudo-homogeneous mixture in a state of fine division through the mutual dispersion of non-miscible phases of which at least one phase is polluted and at least one phase is combustible, pulverizing the mixture in a reaction chamber, gasifying and burning the pulverized misture in the reaction chamber, and recirculating the gaseous substances developed in said chamber in an annular vortex from the center line centrifugally towards the downstream region of said chamber in contact with the walls thereof and centrifugally from the walls to the center line of said chamber adjacent the zone of entry thereinto.

5. Apparatus according to claim 12 wherein the reaction chamber wall includes a cylindrical portion the ratio of the length to the diameter of which is included substantially between 3:1 and 4:1, a convergent section having an apex half-angle of approximately 22*, and a cylindrical outlet throat provided with a downstream partial throttling element.

6. Apparatus according to claim 12 wherein the reaction chamber comprises a wall which includes a conical convergent section the ratio of the length to inlet-section diameter of which is at least 3:1, said conical convergent section being followed by a cylindrical wall provided with a partial throttling element.

7. Apparatus according to claim 12 wherein the reaction chamber comprises a wall including an inlet section and which wall combines an initial conical convergent section with a cylindrical section downstream thereof, the combined conical section and cylindrical section having an overall length at least three times as great as the diameter of the inlet section, said cylindrical section being followed by a convergent section, the apex half-angle of which is between 18* and 22*, and which convergent section is in turn followed by a cylindrical throat provided with a partial throttling element.

11. Apparatus according to claim 12 wherein the reaction chamber is multicellular and formed by a plurality of individual chambers open at their outlet ends and the lengths of which are equal to at least twicE their diameters, said plurality of chambers being disposed within and opening into a main homogenization chamber which may be cylindrical, conical or conical and cylindrical and which terminates in a convergent section having an apex half-angle of approximately 22*, which convergent section is in turn followed by a cylindrical throat provided with partial throttling means and opening into an expansion chamber.