FI72709B - ANORDNING FOER BEHANDLING AV FLYTANDE, HALVFLYTANDE ELLER PASTFORMIGA AEMNEN MED AEMNEN I ANNAN FAS, I SYNNERHET I GASFAS. - Google Patents

Description

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Patent meduelat 10 07 1987 C 02 F 11/06, F 23 G 7/00, (51) Kv.lk. * / Lnt.CI. «B 01 J 10/00 FINLAND —FINLAND (21) PKenttlhakemuj - Pitenunsöknlng 792279 ( 22) Application date - Ansöknlngjdig 20.07-79 (Fh * * (23) Starting date - Giltlghetsdag 20.07 * 79 (41) Has become public - Blivit offentlig 22.01 .80

National Board of Patents and Registration of Finland Date of display and hearing. - 31.03.87

Patent and registration authorities '' Ansökan utlagd och utl.skriften publicerad (86) Kv. application - Int. ansökan (32) (33) (31) Privilege claimed — Begärd priority 21.07.78

France-France (FR) 7821658 Proven-Styrkt (71) Rhone-Pou1enc Industries, 22, Avenue Montaigne, Paris, France-France (FR) (72) Frangois Prudhon, Versailles, Augustin Scicluna, Aubervi11iers, France-France (FR) FR) (7 * 0 Berggren Oy Ab (5 ^ 0 Apparatus for treating liquid, semi-liquid or pasty substances in the second phase, in particular substances in the gas phase - Anordning för behandling av flytande, halflytande eller pastfor-miga mämnen med ämnen i annan fas, i syn gasfas

The present invention relates to an apparatus for treating liquid, semi-liquid or pasty substances with substances, in particular in the gas phase.

In particular, the invention relates to an apparatus which can be used for treating liquid substances, possibly containing solid particles in the form of a suspension, with a high-temperature gas. Such a treatment is common, for example in the treatment of waste water, whereby solids are formed through oxidation.

Many types of solutions have been proposed to solve this problem.

FR-A-2 075 354 proposes a method for rendering liquid industrial waste harmless by converting it into solid waste, treating the waste with a silicate solution and a substance which binds the silicate.

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It is clear that the solution presented in FR-2 075 354 is not simple because it uses compounds which are not present in the effluent, because the process comprises several steps and because the process produces a compound which itself has to be eliminated, which in the above case makes it necessary to form solid wastes which are insoluble in water when diluted, in which case they may be incorporated into certain soil layers as soil improvers.

FR-A-2 320 268 discloses a completely different solution based on contacting water with a pH o above 7 with pure, technical oxygen at a pressure between atmospheric pressure and 20 bar at a temperature of 20-200 ° C. , until the sulfur has been converted to thiosulphates, and then converting these thiosulphates to sulphates by the action of technical oxygen at pH 0-5 or pH 0-8 in the case of effluents not containing sulphates, at a temperature of 20 to 200 ° C and up to 20 bar, possibly in the presence of catalysts.

This solution is also time consuming and involves several operations involving both physical and chemical treatments.

FR-A-2 406 610 proposes the exposure of waste water to simultaneous spraying and oxidative heat treatment, after which the solid waste is separated from the volatile compounds.

It has also been proposed to apply in practice the method described in FR-A-2 257 326, in which the substances present in the different phases are brought into contact with each other and the at least one phase has a rotational flow symmetrical with respect to its axis of rotation, and at least one phase is fed with a vortex flow. wherein the force of the units of the vortex flow volume units relative to the volume units of the axial phase is such that the vortex flow simultaneously causes the atomization, disintegration and movement of the axial phase and its possible treatment with the eddy current.

The device described in FR-A-2 257 326 consists of an upper part, which in turn consists mainly of an outer jacket, for example cylindrical in shape ending in a tapered nozzle, a perforated inner sleeve which together with the outer jacket forms an annular space, at least one tangential supply line, feeds into the annular space and further through the holes into the center of the inner sleeve, exiting as helical sprays. The axial phase is fed via a line along the symmetrical axis of rotation of the vortex flow to a contact zone consisting, for example, of a double conical space, the upstream part of which has an expanding shape forming an extension to the converging outlet nozzle of the upper part.

However, if high temperature treatments are desired, a gaseous phase with the desired temperature must be provided.

This can be achieved by means of the device described in FR-A-2 276 086, which is a hot gas generator with a cold partition wall which provides a helical flow with symmetrical rotation and in which the flame is enclosed in the central part of the device.

The hot gases generated by this generator can be fed tangentially to the annular space at the top of the device described in the aforementioned FR application 2,257,326.

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However, the major drawback of this combination of supplying hot gas to the annular space and allowing it to flow through the orifice is that the treatment requires a temperature above about 800 ° C, so that the gas formed has exactly this temperature.

However, certain treatments require temperatures in the order of 900 to 1200 ° C.

This requires contact members that can withstand temperatures of this magnitude and also the effect of products treated at these temperatures and in the oxidizing environment, which conventional spray members cannot.

For this reason, FR 2 249 754 proposes a new device for carrying out the method according to FR 2 257 326, comprising a unit for generating a vortex flow, consisting of an annular space-limiting rotating body into which the gas phase is introduced tangentially and a symmetrically distributed manifold which imparts axial symmetry to the helical flow thus formed, the manifold being mechanically independent of the rigid rotating member.

In this way, the unit can be satisfactorily cooled and the gas phase can be brought to a very high temperature.

Unfortunately, the implementation of such a device is not always easy and the object of the present invention is thus to achieve excellent results in a simple manner.

The present invention relates to an apparatus for treating liquid, semi-liquid or pasty substances in a second phase, in particular in the gas phase, which apparatus consists of a combustion chamber and a contact chamber comprising a jacket closed at its upper end by a plate-like lid an inner wall for the gas phase of the orifice, of at least one tangential supply line and for the fuel of an axial injector extending through said cover, characterized in that the jacket terminates downstream of the converging portion into which and that the contact chamber is arranged coaxially with and below the combustion chamber.

The gas phase is preferably fed at a low pressure of less than 1 bar, and preferably 0.2 to 0.5 bar higher than the pressure in the downstream contact chamber, and at a speed generally of 10 to 100 m / s, more preferably 30 to 60 m / s. .

The injection rate of the substance reacting with the gas phase can be in the order of 100-150 m / s.

According to the present invention, the axial phase introduced into the combustion chamber consists of a fuel phase, for example fuel oil or any combustible material, which is injected at the inlet of the chamber along the axis of symmetry of the helical stream.

For this purpose, a conventional spraying method such as a pressure or rotation method can be used, but it is also possible to use the method according to FR-A-2 257 326, according to which droplets are formed by transmitting a kinetic force by means of a high vortex flow.

The helical phase then consists of a combustion gas in the gas phase, usually ambient air, but this embodiment is of course not in any way limiting the invention.

The substance to be treated is fed in liquid, semi-granular or pasty form from the axial end of the combustion chamber. The feed speed is low, in the order of 0.03-10 m / s.

In this way, a symmetrical eddy current sprays the liquid path by transferring kinetic force to it.

In this way, it is possible to treat liquid substances at a high temperature in a simple manner, since the products do not come into contact with the walls and these walls are exposed to the processing temperature.

According to the present invention, the gases at the outlet end of the combustion chamber can be heated to a temperature between 900 and 1200 ° C without disadvantage, which further makes it possible to feed the substance to be treated at ambient temperature.

One particular application of the device according to the invention relates to the treatment of waste water.

It is known that in the latter case it is necessary both to evaporate a large amount of liquid and to carry out an oxidative heat treatment and at the same time to separate the solid residues thus obtained from the volatile compounds.

The device according to the invention is particularly suitable for the treatment of waste water in which the proportion of dry matter is up to 20-30%; some of these dry substances are then susceptible to oxidation, such as sulphides and polysulphides, which are then eliminated as sulphates. In this case, the temperature of the gases at the outlet end of the combustion chamber is preferably 900-1200 ° C and in the contact chamber 350-500 ° C.

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Cooling may also be required at the outlet end of the contact chamber.

A rotation zone which is simply stationary can also be arranged at the outlet end of the contact chamber.

In this way, a dust extraction system is provided.

This system may further comprise a liquid or gas phase spray device with which a binder can be fed or flash cooling can be provided. It is also possible to carry out one or more recirculations and feed several phases simultaneously, in particular by co-spraying.

It is clear that the interest of the present invention is not limited to the pollution problem caused by wastewater.

It is particularly suitable in all cases where a high temperature is required, in particular: - for the rapid evaporation of volatile compounds and, in particular, for the drying of a product in the form of an aqueous suspension or emulsion, or for the concentration of solutions. This is of particular interest in the case of concentration of mineral acids such as phosphoric or sulfuric acid; - mixing methods, and in general the impregnation of solids with liquids; - solidification of the particles while turning them into small spheres or surface treatment of the grains, possibly altering the surface structure of the grains; - to carry out reactions such as chlorination or oxidation in a homogeneous mixture.

However, it is also possible to treat heat-sensitive substances, such as protein-based substances. In this case, the device according to the invention can be used with a high temperature gradient, i.e. operating under conditions which allow good thermal efficiency, while avoiding the decomposition of the substances to be treated, as in the method described in FR application 2,396,250.

According to the invention, the perforated inner wall is suitably perforated for a length which depends on the magnitude of the heat flow and the temperature of the gases.

This perforated wall has substantially circular holes which, at least on the closed end side of the device, must be "thin-walled", i.e. the ratio of the diameter of the holes to the wall thickness must be greater than 5, in which case the minimum wall diameter is not limited by anything other than the strength requirement. There are at least 6 holes and they are divided into at least one circle but preferably several circumferential circles of the cylindrical wall. Most of the holes are placed on the upstream side of the device to promote mixing of the substances to be contacted and at the same time to preheat some of these substances while still protecting the inner walls from the thermal effects of the reaction. The total area of the holes located downstream can be quite small, e.g. 1 / 10-1 / 100 of the total area of the holes.

If D ^ denotes the average inner diameter of the outer jacket and D ^ denotes the average inner diameter of the perforated wall, then 1/2 (D ^ -D ^) should preferably be between 1 and 10 cm, depending on the magnitude of the helical current flow . The diameter is determined as a function of the total heat of reaction and is preferably 0.4 to 0.5- / ¾ mm, where k is the number of kilocalories released by this fuel per hour (i.e., the reaction generally caused) during combustion.

Preferably, it should not be less than 500 mm in the case of a viscous substance, for example heavy fuel oil, which is preferably sprayed in a finely divided and homogeneous form.

The straight, axial fuel supply line does not have any specified dimension. The supply line, which consists of a pipe at least outside the device, must allow both good spraying of the liquid and the inlet of the gas without significant pressure drop. This device can be implemented in a number of different ways. For example, when the fuel is liquid, it is advantageous to use the device described in FR patent application 2,257,326, which eliminates the need to apply pressure to the fuel, or a simple pipe with an outlet-shaped outlet with a welded wire outside the device. down to the gas at which the atomization is carried out, the only additional precaution which must be taken is to avoid the use of a device which would give a large o divergent flow (more than 90 angles) when the liquid is fed.

The gas stream, which is later made to rotate, is fed down the tangential pipeline. The conditions to be taken into account with respect to the cross-section of this pipeline are determined above all by the structural requirements and the concern that this device would not cause excessive pressure losses. As already stated above, a pressure of 0.2 bar is usually sufficient. The opening connecting this tube to the annular jacket is preferably in the vicinity of the downstream end of the combustion chamber.

The fuel is ignited by a conventional device such as a spark plug, which is struck by a spark between the electrodes. This plug can be mounted back in a retractable device comprising, for example, a metal bellows. The spark is formed in the zone where the fuel and the combustion gas are in contact, after which the igniter can be pulled back to the level of the perforated wall.

Of course, it is also possible to ignite the mixture or initiate the reaction by means of a flame.

Due to the advantage that the wall temperature is not very high, the device can be made of ordinary steel. The use of stainless steel or other corrosion-resistant metals only makes sense when it is necessary to completely avoid the presence of oxide dusts.

The use of a refractory is useless.

The fuel may be a gas such as methane or propane, or another light hydrocarbon, by incineration of liquid waste which may contain tar or soot in suspension, or at room temperature a solid melted prior to its injection, for example sulfur. Other quite a variety of substances can be sprayed.

Combustion chambers of different shapes can be used. In particular, an O-ring space provided with a mechanically separate, removable torn hood or distributor can be used, so that a cylindrical shell and a truncated cone-shaped perforated basket with a tangential inlet on the downstream side and holes on the upstream side can also be used.

The part which makes contact is as described in FR-A-2 257 326, with the difference that the exploitable vortex movement is the movement in the combustion chamber.

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The kinetic force of the eddy current must be large compared to the kinetic force of the liquids, at least 100 and preferably 1000-10,000 times. The kinetic force of the gases is thus directed to separate, small droplets of liquid in the direction and intensity of these flows in the convergence zone of these flows. In addition, the velocity of the liquids decreases close to the minimum that allows them to flow continuously. The velocity of the gases can remain so low under these conditions that it does not require high pressures.

The mass ratio of gases to liquids is, of course, selected as a function of many factors, some of which are the temperature of these fluids and the desired end result. For example, when vaporizing liquids, this ratio is at least 2.

The velocities and thus the kinetic forces in the plane of the constricted channel are simply calculated according to the inlet flows of the media and the cross section of this channel, since the pressures have only a small significance. The axial current is considered to be rectilinear and of the same cross-section as the internal cross-section of its conductor, whether or not it protrudes from the choked channel.

The trajectories produced by the gases, on leaving the throttling opening, form one of the two baseline swarms of hyperboloids, i.e. more precisely, a group of baselines of one layer formed by several hyperboloids. These baselines pass through a circle of circles that form a small-width ring located downstream of the constricted channel of the helical current before diverging. This ring surrounds a vacuum zone, the effect of which is applied on the upstream side to the liquid which forms a rectilinear flow and on the downstream side to the gases, causing some of these fluids to circulate back. The liquid disperses into a large number of small droplets, each of which has been taken over and moved by a certain volume of gas 72709 12, which produces a centrifugal effect which improves contact with the vector gas and, in the event of combustion, ensures flame adhesion and stability.

The ratio of gas flow to liquid flow can vary widely, and increasing this ratio reduces the size of the droplets formed.

This method of contacting substances in different physical states can thus be applied to the various operations which are common, especially in the chemical and nutrient industries, by means of the device described above.

In these operations, the vortexed stream is generally a gas or vapor which, when suspended, carries solid or liquid particles which are to be brought into contact with the axially fed substances. A pressure of a few hundred grams per square centimeter (200-500 g / cm) above the pressure in the downstream part of the device is sufficient to ensure good operation of the device. The vortex movement caused by this current, as already mentioned, creates a slight vacuum in the axial part, so that a flow of medium can develop in the inner tube without the need to apply pressure to this medium.

The contact chamber may simply consist of a double cone.

The phase or phases to be treated are then fed into the plane of the throttling point, preferably at a distance from the smallest cross-sectional circle, the size of which varies by plus or minus one radius of this circle.

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Preferably, the outer diameter of the supply line is at least equal to 1/4 of the diameter of this circle and more preferably at least equal to 2/3 of this diameter.

In order not to interfere with the reaction that takes place in the combustion chamber, the substance (or substances) to be treated is simply fed along a curved pipeline, but other types of devices can be used, such as an annular injector located substantially in the plane of the throttling point.

Finally, the cooling zones can be arranged either at the level of the contact chamber, as disclosed in FR application 2,419,754, which provides cooling at the periphery of the phase contact zone, or heat treatment can also be provided in a downstream plane according to FR application 2,396,250. -the product to be treated is exposed to a sharp change in temperature at the end of the treatment, which treatment is particularly suitable for heat-sensitive substances.

In this case, the gases preferably leave the combustion chamber at a temperature of 200-700 ° C and the resulting mixture is subjected to: at the outlet of the contact chamber, a cooling treatment at a temperature of 20-120 ° C.

: The invention will be described in more detail below with reference to the embodiments shown in the accompanying drawings.

Figure 1 shows an apparatus according to the invention corresponding to the general case where a substance is treated with a gas phase; Fig. 2 shows a special case in which an after-treatment device is placed at the outlet of the contact chamber to remove left-hand dust from the device; Fig. 3 shows a special case in which a cooling device is arranged in the device.

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The device according to Figure 1 consists of a combustion chamber 1 and a contact chamber 2.

The combustion chamber 1 consists of a jacket 3 which is closed at its upper end by a plate 4 in which a hole has been made for accommodating the atomizing device 5.

The combustion chamber has an annular space 6, which is bounded on the inside by a cylinder 7 routed from its upstream part.

The gas phase is fed tangentially down the pipe 8, which opens into the annular space 6.

The jacket 3 terminates on the downstream side in a cone 9 which forms a throttling opening 10 into which a curved lead 11 parallel to the axis of rotation of the main part 1 opens substantially in the plane of the throttling opening.

The contact chamber 2 consists of a double cone, the upstream diverging part of which forms an extension of the converging end part of the combustion chamber 1.

The device according to Fig. 2 comprises a combustion chamber 1 and a contact chamber 2 similar to Fig. 1, but a dust extraction device 12 is arranged at the outlet of the double cone 2, comprising a jacket 13 with a receiving cone 14 immediately below the double cone 2 and possibly a liquid supply line 15, wherein said frustoconical jacket 13 continues as a cylinder 16 which allows the rotational movement to continue and which leads the products to the centrifugal separator 17. The solid product exits at 18 and the gases at 19.

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The device according to Figure 3 illustrates another embodiment, in particular for heat-sensitive substances.

This device is similar to the device according to Figure 1, except that a cooling system is arranged at the outlet of the double cone 2, comprising an upper part with a perforated wall 21, a tangential line 22, a pipeline 23 and a cyclone 24.

Of course, the present invention is not limited to the embodiments shown in the drawing. Thus, for example, contact chambers which are not double-cone-shaped but have a cylindrical intermediate part can be used.

For example, the following method can be performed with the device according to Fig. 2.

Wastewater containing 20% by weight of NaCl, 3-4% by weight of Na sulphate and about 5% by weight of organic substances containing polysulphides is treated.

The device used has a part 1 with a total height of 193 mm, of which 43 mm is the proportion of the converging part.

The diameter of the jacket 3 is 120 mm and the diameter of the perforated cylinder 7 is 82 mm. The diameter of the orifice is 18 mm and the outer diameter of the conduit 11 at the orifice is 12 mm, thus representing 2/3 of the diameter of the orifice 10, and finally the inner diameter of the tube member 11 is 4 mm.

o

The apex angle of the upper cone of a double cone is 90.

Air is fed into the combustion chamber up to pipe 8 at a flow rate of 60 Nm / h and a pressure of 0.4 bar. The fuel injected all the way to tube 5 is propane.

16 72709 In this example, the propane injection is adjusted so that o a temperature of about 1000 C is brought to the level of the orifice and the supply of water to be treated is adjusted so that a temperature of the order of 500 C is obtained at the outlet of the double cone.

The solid phase contains 3 kg of NaCl and 3 kg of sodium sulfate per 30 kg of treated water. In particular, it is found that the gas phase does not contain fine particles and consists not only of flue gases essentially of water vapor, which contains only trace amounts of SO.

This example shows that the device according to the invention is useful for treating heat-sensitive substances without good decomposition and for treating, for example, contaminants at high temperatures.

As already mentioned, this example is not intended to limit the invention, but a similar device can be used in particular for the concentration of acids or for the treatment of products such as gypsum. During the operation, other products can also be fed in by co-spraying them, or some binder, or recycle certain products.

li.

Claims (5)

72709 17 Apparatus for treating liquid, semi-liquid or pasty substances in a second phase, in particular substances in the gas phase, which apparatus consists of a combustion chamber (1) and a contact chamber (2), the combustion chamber (1) comprising a jacket (3) closed at its upper end a plate-like cover (4), an annular space (6) bounded on the inside by a perforated inner wall (7), a throttling opening (10), at least one tangential supply line (8) for the gas phase and an axial injection member extending through said cover (4) (5) for fuel, characterized in that the jacket (3) terminates on the downstream side of the converging part (9), which opens along the axis of rotation of the combustion chamber (1) substantially in the plane of the throttling opening (10) for the injection device (11). 2) is arranged coaxially with and below the combustion chamber (1). Device according to Claim 1, characterized in that the inner wall (7) consists of a removable body. Device according to Claim 1 or 2, characterized in that the annular space (6) is O-ring-shaped. Device according to one of Claims 1 to 3, characterized in that the ratio of the outer diameter of the substance injection device (11) to the inner diameter of the throttling opening (10) is at least 1/4, preferably 2/3. Device according to one of Claims 1 to 4, characterized in that a cooling system is provided at the outlet of the combustion chamber (1).