AT510049A2 - APPARATUS AND METHOD FOR SEPARATING GAS FROM FLOTATION FOAM - Google Patents

Description

Plant and method for separating gas from flotation foam

Background of the invention

The invention relates to a gas separation plant for separating gas from flotation foam, wherein the plant comprises at least one gas separation and at least a portion of the gas contained in the flotation foam is separated from the flotation foam in the flotation foam by destroying gas bubbles in the flotation foam.

The invention furthermore relates to a method for separating gas from flotation foam, wherein gas bubbles present in the flotation foam in the gas separation space of a gas separation plant are destroyed in the process in order to separate at least part of the gas contained in the flotation foam from the flotation foam.

The flotation cells are used to remove inks or other impurities from fiber suspension made from dispersed and sorted recycled paper. This measure is also called deinking. The purpose of deinking is to produce as white and clean recycled fiber as possible. Flotation depletion uses flotation cells, with flotation being performed in the cells such that the weak, about one-percent -2- -2- • • ···························

Fiber suspension is added to soap as a flotation chemical or other flotation-promoting, surface-relaxing chemical. The fiber suspension can be supplied to the flotation tank of the flotation cell, for example via an injector, wherein gas is added to the fiber suspension flow in the injector, typically air. Printing ink and impurities stick to air bubbles in the flotation basin, which rise to the surface of the fiber suspension located in the flotation basin. In this case forms on the surface of the fiber suspension, printing inks, other impurities, ash and possibly also to a small extent also containing fibers flotation foam, which can be removed as a reject from the flotation tank, for example, an overflow or by scraping, forming a Rejektstrom, the in practice a flotation foam containing liquid stream. The accept or accept current that forms in the flotation cell, i. the cleaned of impurities fiber suspension stream is discharged through the accepting part of the flotation cell.

In the publication DE 20204981 oil a solution for separating air from the flotation foam is shown. In the solution in question, the flotation foam containing stream is passed by gravity over an overflow down into a drain line, in the interior of which a wing equipped and driven by a motor rotatable rotor is arranged. When the rotor is running, it displaces the stream containing foam, which flows into the drainage pipe, against the walls of the walls of the walls of the walls

Drain line into a rotating motion and / or throws the stream containing foam to the walls of the drain line, whereby the foam bubbles burst and the air released from the bubbles separates from the foam. In a solution according to the publication DE 20204981 U1, however, the rotor blades can easily break caused by a sudden increase in the amount of the foam-containing stream and the associated rotor-directed increase in running resistance, thereby either weakening or completely reducing the reject treatment for deinking can be stopped.

Brief description of the invention

The object of the invention is to obtain a novel solution to separate gas from flotation foam. It is characteristic of a plant according to the invention that the plant includes at least one construction delimiting the gas separation space or a structure arranged in the gas separation space, against which or at the flow containing flotation foam to be fed along the flotation foam in the gas separation space at an increased flow velocity for destroying gas bubbles in the flotation foam is arranged controllable. It is characteristic of a process according to the invention that the stream containing the flotation foam flows at an increased flow velocity at least towards or along a wall which delimits the gas separation space. 4... 4 4 * 4 *

Construction or arranged in Gasabscheideraum construction for destroying gas bubbles in the flotation foam is supplied.

The gas separation plant for separating gas from the flotation foam comprises at least one gas separation space, wherein at least part of the gas contained in the flotation foam is separated from the flotation foam in the gas separation space by destroying gas bubbles in the flotation foam. The plant includes at least one construction delimiting the gas separation space or a construction arranged in the gas separation space, against which or at the flow containing flotation foam supplied in the gas separation space with controllable flow velocity is controllably arranged for destroying gas bubbles in the flotation foam.

Upon delivery of the flotation foam-containing stream at an increased flow velocity towards or along a structure defining the gas separation space or in the gas separation space, impact or compression against the stated construction is caused, effectively destroying the gas bubbles present in the flotation foam.

Brief description of the figures

The invention will now be described in more detail in connection with preferred embodiments with reference to the accompanying drawings, wherein -5- -5- • φ φ * · • φ • * • • • * Φ • Φ • · ΦΦ Φ Φ · Φ ΙΜ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ Φ ΜΙΙ Φ ΦΜ

FIG. 1 shows, schematically from the side, a gas separation plant for separating off gas from flotation foam, FIG.

FIG. 2 shows, schematically from the side, a second gas separation unit for separating gas from flotation foam, FIG.

FIG. 3 shows, schematically from the side, a third gas separation unit for separating gas from flotation foam, FIG.

FIG. 4 schematically shows, from the side, a fourth gas separation unit for separating gas from flotation foam, FIG.

Fig. 5 schematically illustrates a gas separation plant of Fig. 4 as viewed from above, Figs. 6a to 6f schematically illustrate some possible controls which may be used to control the flow of flotation foam, Figs. 7a to 7d schematically illustrate some possible nozzles, the flow containing the flotation foam can be used, and

Fig. 8 schematically illustrates, viewed from the side, a nozzle plate which may be used to control the flow of flotation foam. -6- • * ··· «·· ** • * * * *« * * · · · * * · ···· • · * * * * * * * · · »

Detailed description of the invention

FIG. 1 schematically shows a gas separation plant 1 or plant 1 for separating gas, typically air, from the flotation foam. A plant 1 according to FIG. 1 includes a pump 2 which is arranged to supply a reject stream comprising a deinking process for pulp suspension, for example along a pipe block 3, and a flotation foam at an increased flow rate into a gas separation chamber 4 whose walls 5 delimiting a Gasabscheideraum 6, in which the flotation foam containing stream is passed in a direction schematically shown by an arrow A. The pump 2 may be, for example, a centrifugal pump, a plate pump, an engine block pump, an asymmetric rotor pump, or another pump capable of pumping gaseous liquids. For the sake of clarity, the deinking process for a fiber suspension or the flotation foam itself is not shown in FIG.

The pump 2 forms a pressure supply which thus supplies the flow containing flotation foam into the gas separation space 6 formed by the gas separation chamber 4 via a channel 7 connecting the pump 2 and the gas separation chamber 4. The gas separation chamber 4 shown in FIG. 1 is a cylindrical space from the upper part and a conical space narrowing downwards from the lower part. Depending on the form of implementation or shaping of the gas separation chamber 4 used, one or more walls 5 and the upper end 5 'of the gas separation chamber 4 thus bound the inside of the gas separation chamber 4' Gas separation chamber 4 to be positioned Gasabscheideraum 6. In Gasabscheideraum 6 is a control 8, which in the gas separation chamber 6 for controlling the coming at an increased flow velocity from the direction of the upper side of the gas separation chamber 4, flotation containing stream against or in the direction of the wall 5 is what is shown schematically with an arrow B. When hitting the wall 5 of the gas separation chamber 4, the gas bubbles present in the flotation foam burst, whereby the gas present in the gas bubbles is separated or released from the flotation foam and escapes or is removed from the gas separation space 6. Upon deposition of gas present in the flotation foam from the flotation foam, the liquid content of the flotation foam-containing stream increases and the liquid in question can be removed from the gas separation chamber 4 via a liquid outlet opening 9. The cited liquid outlet 9 in the gas separation chamber 4 of FIG. 1 is positioned in the lower part of the gas separation chamber 4.

The flow containing flotation foam is fed into the gas separation space 6 at such a rate that the velocity of the flotation foam-containing stream when impinging on the walls 5 delimiting the gas separation space 6 is approximately 1 to 10 m / s, preferably 3 to 8 m / s. The lower the speed required for destroying the gas bubbles present in the flotation foam, the lower the energy consumption required for pumping and that required for pumping

Pipe constructions required wall thickness. Depending on the material composition of the flotation reject stream, such as the ratio of liquid and flotation foam, the amount of impurities and the quality of the soap to be used in the flotation, the flow rate is appropriately adjusted so that in the gas separation space 6 the bubbles present in the flotation foam effectively be destroyed and the gas from the gas separation chamber 6 escapes or can be removed. In some cases, a low velocity in the gas separation space 6 is sufficient, but in some cases a higher velocity is needed. The initial flow rate in the lower part of the gas separation space 6 is preferably 0.1 to 0.3 m / s. As a result, the gas present in the stream can still be separated from the stream, which completes the removal of gas from the reject stream in Deinkvorgang.

In the embodiment of Fig. 1, the control 8, i. the flow-direction-controlling element 8 positioned in the gas-separating space 6, containing the flotation foam, is plate-like and has a tapered upper cone shape. This control 8 controls the flow containing flotation foam at an increased flow rate into the gas separation space 6 in a direction indicated by an arrow B at any angle against the walls 5 of the gas separation chamber 4, thereby bursting the gas bubbles present in the flotation foam and expelling the gas can separate the flotation foam. Part of the gas bubbles present in the flotation foam can also be found at -9- * * · • t • · * · • ft ft ft • * ft • • • • • ft ft ft ft • ft • ft ft ft ft • ft

Impact of Flotationsschauin containing stream are destroyed on the control 8.

The control element 8 may also be a straight plate, shell-like, a dome, pyramid or a polygon, or contain tines controlling the current. The control element 8 may also be uniform in shape in such a way that the current does not bounce against it, but rather is controlled by it against the wall 5 of the gas separation chamber 4.

Using the variation possibilities, a suitable control element 8 is selected depending on the quality of the flotation reject material in such a way that the gas bubbles in the flotation foam of the flotation reject material are destroyed as effectively as possible when flowing against the control element 8 and / or the wall 5 of the gas separation chamber 4.

Various possible embodiments for the control element 8 are shown in FIGS. 6a to 6f. In each of FIGS. 6a to 6f, the upper part of the figure describes the control element 8 seen from the side, and the lower part of the figure describes the control element seen from above.

The control elements 8 of FIGS. 6a to 6d have in common that they are increasingly tapered downwards from the cross-sectional area. The control 8 in Fig. 6a is similar in shape to a typical cone. The control element 8 according to FIG. 6b is similar in shape to a polygonal cone, which has a total of six sides 32 or -10- -10- ♦ · φ * * * * * * * * * * * * * * * * * * · · · · · · · · · · · · · · · · · ·. φ »« Φ φφ »φ Φ« Φ «Φ Φ · * · Φ« f φ · φφ φφ * «« «:« «·

Sections 32 which are arranged at an angle to each other. The control element 8 according to FIG. 6 c is similar in shape to the control element 8 of FIG. 6 b, but still has a dome-shaped surface 33 in the upper part. All control elements 8 according to FIGS. 6a to 6c are particularly well suited for an operating situation in which the flow containing flotation foam reaches the control element 8 either from below or above.

The control element 8 according to FIG. 6d has a sawtooth-like wave profile 34 or a groove 34, in which the depth of the grooves increases from the middle part of the control element 8 to the edges of the control element 8. The cited clogging disturbs the flow containing flotation foam, which effectively affects both the destruction of the gas bubbles in the flotation foam and the escape of gas from the stream released from the destroyed gas bubbles. The controls 8 of FIG. 6d may be used to control both the current coming from above and from below, but the control 8 of FIG. 6d is particularly well suited to the upwardly open grooves for effective control of the current Controlling the electricity coming from above.

The control 8 of Fig. 6e is a straight plate which is equally well suited for controlling the flow coming from both above and below. The control element 8 according to FIG. 6f also essentially comprises a straight plate-shaped section, but in the middle of the control element 8 there is furthermore a console 35 directed downwards, with the result that the one of 11 11

The current coming in the direction of the sides of the control element 8 against the wall of the gas separation space 6 can be uniformly controlled.

The flow direction of the flotation foam-containing stream can also be controlled with one or more nozzles, which is / are arranged, for example, at the end of the channel 7 extending into the gas separation space 6. The cited one or more nozzles is / are arranged in such a position that the nozzle 16 controls the flow containing flotation foam toward the walls 5 delimiting the gas separation space 6. Using multiple nozzles, they divide the flotation foam containing stream to be fed as a unitary stream into the gas separation space into a plurality of separate streams and control the streams at any angle against the walls 5 of the gas separation space 6. Thus, the one or more forms a plurality of nozzles in itself the flow control element containing the flotation foam.

The nozzle can be shaped in many different ways and, for example, be round, rectangular, polygonal, narrowing or widening. Since some of the gas bubbles in the flotation foam can already be destroyed in the nozzles, the cross-sectional area of a nozzle is dimensioned sufficiently small so that the gas contained in the stream emerging through the nozzle and separated from the flotation foam can be separated from the stream emerging from the nozzle , In addition, the nozzle heads can be formed in many different ways, such as straight or oblique. The number of nozzles and the positioning of the nozzles relative to one another are determined by the gas separation capacity required by plant 1.

Some nozzles 16 are shown in FIGS. 7a to 7d. On the left side in Fig. 7a, a nozzle 16 is seen from the front and shown on the right side from the side. In Fig. 7a, a nozzle is shown having a circular nozzle opening 21 as the cross-sectional area of the nozzle 16 decreases toward the head of the nozzle 16. In Fig. 7b, a nozzle is shown having a square-shaped nozzle opening 21, as the cross-sectional area of the nozzle 16 decreases toward the head of the nozzle 16. In Fig. 7c, a nozzle is shown having a cross-shaped nozzle opening 21, when the cross-sectional area of the nozzle 16 also decreases towards the head of the nozzle 16 out. The nozzles according to FIGS. 7a to 7c can be used for controlling the flow of flotation foam either for example to a control element 8 similar to FIGS. 6a to 6f or when installing the nozzle 16 in a suitable position with respect to the wall defining the gas separation space 6 5 are used to the gas separation space 6 bounding wall 5 out.

FIG. 7 d shows a nozzle 16 which comprises nozzle parts 36 and teeth 36 at the nozzle head, wherein the nozzle openings 21 are located at the end of the nozzle parts 36. The nozzle 16 according to FIG. 7 d is used automatically for controlling the flow containing flotation foam to the walls 5 delimiting the gas separation space 6. -13- «·« · • * ¥ ¥ • * ¥ ¥ * • I 1 «« * · w · 4 • · • ♦ • MM 1 »· + * * ♦» f «· 4» · I «• ♦ * * · ♦ 4 ♦ 1 ♦ ♦ • ··· Ml

The nozzle parts 36 are directed away from the central part of the nozzle 16 substantially in the radial direction of the nozzle 16. The nozzle parts 36 shown in solid lines on the right side in Fig. 7d are directed at a slight angle rearward with respect to the head of the nozzle 16, and the nozzle parts 36 shown with a broken line are with respect to the head of the nozzle 16 after directed in front. The nozzle parts 36 could also be directed substantially in the tangential direction of the nozzle 16, whereby a turbulence can be achieved with the nozzle 16 in the gas separation chamber 6, in which the gas to be separated from the flotation foam also over the forming in the middle of the fluidizing free Remove airspace.

By using the nozzles 16, the nozzle plate 37 shown schematically in FIG. 8 can also be formed, which has a support structure 37 'and in the context of which nozzles 16 are arranged, of which only two are shown in FIG. 8 for the sake of clarity Pieces are shown. The cited nozzle plate 37 may be positioned, for example, at the end of the channel 7 extending into the gas separation space 6. The nozzles 16 are positioned on the nozzle plate 37 in such a manner that the flow containing flotation foam leaving the nozzle orifices 21 is directed away from the nozzle plate 37, i. to the walls 5 delimiting the gas separation space 6. The nozzle plate 37 can be positioned either fixedly or rotationally, whereby the currents flowing out of the nozzles and separated from one another, containing flotation foam, spread more uniformly over the entire region the gas separation chamber 6 bounding wall of Gasabscheidekammer 4 can be directed.

If the flow-controlling element of the flotation foam containing flow control element consists of only a single nozzle 16, the said nozzle can also be arranged to rotate. A single nozzle is simple and advantageous as a construction. By using the mentioned single nozzle or a very small number of nozzles as the flow controlling element, the advantage is achieved that more free volume remains around the stream entering the gas separation space 6 from the nozzle or nozzles, resulting in separation of gas from the stream is conducive.

The nozzle 16 may be arranged to control the flotation foam-containing stream toward some of the control elements 8 shown in FIGS. 6a to 6f, which is shown schematically later in the embodiment according to FIG.

The flow containing flotation foam is most preferably controlled in a direction perpendicular to the wall 5 delimiting the gas separation space 6 of the gas separation chamber 4, preferably at any angle in the + 45 ° angular range and more preferably at any angle in the + 20 ° angular range. The closer the direction in question is to a right-angled direction with respect to the indicated wall 5, the more effectively the gas separating from the flotation foam escapes from the relevant stream and the less the -15-t * * · · < 4 to the liquid outlet 9 further out flow from the flotation gas separated air with it.

The plant 1 further includes a first Gasausleitblock 10, which is arranged at the upper part of the gas separation chamber 4, wherein the over the Gasausleitblock 10 separated from the flotation foam and upwardly rising gas can escape by gravity from the Gasabscheideraum 6. The gas escapes by gravity from the gas separation space 6 more effectively when the gas discharge block 10 is directed vertically upward. The escape by gravity becomes weaker if the gas discharge block 10 is only in a little upward rising direction, i.e. almost horizontal. The gas to be discharged from the gas separation space 6 can be returned, for example, to a flotation cell which belongs to the deinking process.

By controlling the flotation foam-containing stream to be fed into the gas separation space 6 at an increased flow rate against one or more walls 5 delimiting the gas separation space 6, i. against one or more constructions delimiting the gas separation space 6, a collision of the flow containing flotation foam is effected on one or more walls 5 delimiting the gas separation space 6, whereby the gas bubbles present in the flotation foam are effectively destroyed by the mentioned impact.

As another possible feature in a plant 1 after -16- 6iit

Fig. 1 shows a vacuum pump 11, which may for example be a liquid ring pump. In addition, in Figure 1 as a further possible feature for a system 1, a second Gasausleitblock 12 is shown, which is connected to the pump 2; the gas discharge block 12 can be used to remove the gas separating in the pump 2 from the flotation foam, for example in the case of a centrifugal pump from the vicinity of the hub in the impeller of the pump 2, when the pump 2 removes the gas bubbles present in the flotation foam during pumping the flotation foam containing stream destroyed in the direction of Gasabscheidekammer 4. Furthermore, in Fig. 1 as a further possible feature, a third Gasausleitblock 13 is shown, which is connected via the upper part of the gas separation chamber 4 with the gas separation chamber 6, whereby with the vacuum pump 11, the gas separating from the flotation foam gas also with negative pressure from the gas separation 6 can be removed. With the help of the vacuum pump, the separation of the gas released from the destroyed foam bubbles from the flotation foam can be made more effective. Further, in Fig. 1, a gas supply block 14 connected to the vacuum pump 11 for supplying the gas collected by the vacuum pump 11 from the flotation froth, for example, back to a flotation cell belonging to the deinking process is shown.

In the system 1 according to FIG. 1, a vent valve 15 positioned in the channel 7 between the pump 2 and the gas separation chamber 4 is shown as yet another possible feature, through which the gas accumulated in the recited channel, separated from the flotation foam, opens from the cited one Channel 7 can be removed. The said vent valve 15 is positioned in the horizontal of the system 1 at the highest point of the stated channel 7, at which the separated from the flotation gas accumulates in the channel 7. In the case shown in Fig. 1, the gas to be discharged from the duct 7 via the vent valve 15 may be released into, for example, the factory floor, which is possible in the case where the gas is air.

In Fig. 2, a second Gasabscheideanlage 1 for separating gas from the flotation foam is shown schematically. To a plant 1 of Fig. 2 includes a pump 2, which is arranged to supply a coming from a deinking process for fiber mass suspension, for example, along a tube block 3 coming liquid and a flotation containing Rejectstrom with an increased flow rate in a Gasabscheidekammer 4, one or a plurality of walls 5 define a gas separation space 6, in which the flotation foam containing stream is passed in a direction schematically represented by an arrow A. FIG. 2 also shows a pump driven by a motor 2 '.

The pump 2 thus forms a pressure supply which feeds the flow containing flotation foam into the gas separation space 6 formed by the gas separation chamber 4 via a channel 7 connecting the pump 2 and the gas separation chamber 4. In a solution according to FIG. 2, the channel is guided from the side or flank of the gas separation chamber 4 through its wall 5 into the gas separation space 6. The gas separation chamber 4 shown in FIG. 2 is a cylindrical space at the upper part and at the lower part a downwardly narrowing conical space whose wall 5 and upper end 5 'so limit the gas separation space 6 to be positioned inside the gas separation chamber 4. In the gas separation chamber 6 there is a control element 8, which in FIG. 2 is a downwardly widening conical plate-like element. The control 8 controls the supplied into the gas separation chamber 6, containing flotation foam flow through the channel 7 and located at the end nozzle 16 against the control 8 from the underside vertically against or towards the wall 5 of the Gasabscheidekammer with an increased flow velocity, what is shown schematically with an arrow B. Upon impact with the wall 5 of the gas separation chamber 4, the gas bubbles present in the flotation foam burst, whereby the gas present in the gas bubbles is separated or released from the flotation foam and escapes or is removed from the gas separation space 6. Some of the gas bubbles present in the flotation foam can also be destroyed when the flotation foam-containing stream hits the control element 8. Upon deposition of gas present in the flotation foam from the flotation foam, the liquid content of the flotation foam-containing stream increases and the liquid in question can be removed from the gas separation chamber 4 via a liquid outlet opening 9. The cited liquid outlet 9 in the gas separation chamber 4 of FIG. 1 is positioned in the lower part of the gas separation chamber 4.

To the plant 1 of Fig. 2 further includes a first Gasausleitblock 10, which is arranged at the upper part of the gas separation chamber 4, wherein the over the Gasausleitblock 10 separated from the flotation and rising gas can escape by gravity from the gas separation chamber 6. Alternatively, in connection with the Gasausleitblock 10, a suppressor or a fan can be arranged to remove the separated from the flotation gas from the gas separation chamber 6.

As a further possible feature in a plant 1 of FIG. 2, a vacuum pump 11 is shown, which is connected to a second Gasausleitblock 12 through which the vacuum pump 11 in the pump 2 can be removed from the flotation foam gas, when the pump 2 destroys the gas bubbles present in the flotation foam when pumping the flotation foam-containing stream in the direction of the gas separation chamber 4.

In FIG. 3, a third gas separation plant 1 for separating off gas from the flotation foam is shown schematically from the side. A plant 3 according to FIG. 1 includes a pump 2, which is arranged to receive a reject stream containing a liquid flow and a flotation foam from a deinking process for pulp suspension, for example along a pipe block 3, at an increased flow rate into a flow velocity of -20.degree - • ·

• · · · ·

Supply Gasausleitbehälter 17, the wall 18 and ends 19 define a Gasabscheideraum 6, in which the flotation foam-containing stream is passed in a direction schematically shown by an arrow A. In Fig. 3, a driven by a motor 21 pump is shown.

The pump 2 thus forms a pressure supply which feeds the flotation foam-containing stream into the gas separation space 6 formed by the gas outlet container 17 via a channel 7 connecting the pump 2 and the gas outlet container 17. In a solution according to FIG. 3, the channel 7 is guided through the wall 18 of the Gasausleitbehälters 17 from the bottom of the Gasausleitbehälters 17 via the / merged in the channel 7, one or more feed blocks 20 in the Gasabscheideraum 6. The Gasausleitbehälter 17 shown in Fig. 2 is substantially cylindrical and its wall 18 and ends 19 thus limit the inside of the Gasausleitbehälters 17 to be positioned Gasabscheideraum 6. At that end of the feed blocks 20, which is positioned inside the Gasabscheideraums 6, located a nozzle 16, which via the channel 7 and one or more associated with this feed blocks 20 the incoming at an increased flow rate, flotation containing stream against or in the direction of above the feed blocks 20 existing portion of the wall 18 of the Gasausleitbehälters 17 in the with a Arrow B schematically illustrated manner controls. The nozzle 16 thus forms a control for controlling the in the

Gasabscheideraum 6 to be supplied, flotation containing stream against or towards the wall 18 of Gasausleitbehälters 17, or against or in the direction of the Gasabscheideraum 6 limiting construction. Upon impact with the wall 18 of the Gasausleitbehälters 17 the existing bubbles in the flotation foam burst, whereby the gas present in the gas bubbles is separated or released from the Flotationsschäum and escapes from the Gasabscheideraum 6 or removed. Some of the gas bubbles in the flotation foam can also be destroyed in the nozzle 16. Upon deposition of gas present in the flotation foam from the flotation foam, the liquid content of the flotation foam containing stream increases and the liquid in question can be removed via an overflow 22 and a liquid outlet 9 from the Gasausleitbehälter 17. The cited liquid outlet 9 in Gasausleitbehälter 17 of FIG. 1 is positioned in the lower part of the Gasausleitbehälters 17. The liquid to be discharged from the gas discharge tank 17 can be returned to the process, for example, via a water tank.

To the plant 1 of Fig. 3 further includes a first Gasausleitblock 10, which is arranged at the upper part of Gasausleitbehälters 17, wherein the over the Gasausleitblock 10 separated from the flotation foam gas, for example, by gravity or with a vacuum pump or with a fan from the Gas separation 6 can be removed. In the system after »« «» · ♦ # · -22-

FIG. 3 shows, as a further feature, a control valve 23 for evacuation of gas, the function of which can be controlled by means of a negative pressure control device 24 and a negative pressure measuring element 25. The negative pressure measuring member 25 measures the negative pressure acting in the gas separation space, and the negative pressure control means 24 can control the position of the gas discharge control valve 23 based on the measurement in question to obtain a desired negative pressure in the gas separation space 6. The gas discharge control valve 23, the negative pressure control device 24, and the negative pressure measuring element 25 thus constitute a control circuit for controlling the negative pressure level to be formed in the gas separation space 6. The stated negative pressure level may, for example, vary between 20 and 90 kPa (a).

As a further possible feature in a plant 1 of FIG. 3, a vacuum pump 11 is shown, which is connected to a second Gasausleitblock 12 through which the vacuum pump 11 in the pump 2 can be removed from the flotation foam gas, when the pump 2 destroys the gas bubbles present in the flotation foam when pumping the flotation foam-containing stream in the direction of the Gasausleitbehälters 17.

FIG. 4 schematically illustrates, viewed from the side, a fourth installation 1 for separating gas from the flotation foam, and FIG. 5 shows a system according to FIG. 4, seen schematically from above, in cross section along the line A - A shown in FIG -23- -23- Μ · · * Μ * «

* * • tM * · »« * * t «ι * ·» · * * * I t · < · «* * * ···«

To the plant 1 according to FIG. 4, a gas separation cyclone 26 is included, to which the stream containing flotation foam accumulated in the working chamber above the gas separation cyclone 26 in a reject space 28 of the flotation cell 27 can be guided along the channel 29. As a result, the potential energy 2U resulting from the difference in height of the flotation cell 27 and the gas separation cyclone 26 is converted into kinetic energy for the flow containing flotation foam, whereby the flow containing flotation foam can be conducted at an increased flow rate into the gas separation cyclone 26 in the manner shown schematically by an arrow A. , The gas separation cyclone 26 is substantially cylindrical and its wall 30 and upper end 30 'define the gas separation space 6 to be positioned inside the gas separation cyclone 26. The gas separation cyclone 26 may have the supply block 31 positioned on its side tangential to direct the flow of flotation foam into the gas separation space 6 along the walls of Gasabscheideraums 6 belong. The indicated feed block 31 can thus form a control element to be connected to the gas separation space 6 for controlling the wall 30, which delimits the gas separation space 6 at an increased flow velocity, i.e., along the structure delimiting the gas separation space 6, and containing flotation foam to be supplied to the gas separation space. Alternatively, the channel 29 may be directly connected to the gas separation space 6 to achieve the same effect. As a consequence of the above-mentioned potential energy of the -24- I converted into kinetic energy. »4M · t 4 4 *

Flotationsschaum containing stream and the tangential feed, the containing at an increased flow rate in the gas separation chamber 6 containing flotation foam is brought into a swirling motion along the gas separation chamber 6 bounding wall 30 in the manner shown schematically by an arrow B, which is present in the current Flotation foam compressed and burst therein gas bubbles burst, the gas contained in the flotation foam is released. Upon deposition of gas present in the flotation foam from the flotation foam, the liquid content of the flotation foam-containing stream increases and the liquid in question can be removed from the gas separation cyclone 26 via a liquid outlet opening 9. The cited liquid outlet 9 in the gas separation cyclone 26 of FIG. 4 is positioned in the lower part of the gas separation cyclone 26.

A foam column formed by the flotation foam flowing from the flotation cell into the channel 29 is preferably at least 2 m, more preferably at least 5 m, and most preferably at least 10 m, in terms of the exit height of the feed block 31. In this way, the speed of the flotation foam flowing into the gas separation space 6 can be raised so high that the separation of gas effectively takes place via a compression of the flotation foam caused by the swirling to be formed in the gas separation space 6 and the free air space to be formed in the middle of the swirling. With these heights of the foam column can be increased needed

Flow rate of the flotation foam for separating gas can also be accomplished in the realizations of Fig. 1 to 3, in which the flotation foam flows at an increased flow rate for separating gas against the arranged in the gas separation chamber 6 construction or the Gasabscheideraum bounding wall.

The inner diameter of the channel 29 of FIG. 4 or the pipe corresponding thereto is, for example, 30 to 60 cm, and the inner diameter of the cylindrical portion of the gas separation cyclone 26 is preferably at least twice as large with respect to the inner diameter of the channel 29, which preferably has an inner diameter from 50 to 150 cm. With such a design, the reject of the flotation cell effectively flows from the flotation cell into the gas separation cyclone, and a large portion of the gas separates from the flotation foam in the gas separation cyclone 26. In the realizations of FIGS. 1 and 2, when choosing the inner diameter for the channel 7 and the gas separation space 6, a corresponding dimensioning can preferably be used. In the realization of Fig. 3, the inner diameter of the gas separation vessel is preferably larger than in the other illustrated realizations, since the filling of the gas separation space caused by the overflow threshold on the gas separation space reduces the free wall and the gas separation space.

Between the channel 29 of FIG. 4 and the gas separation space 6, therefore, also a feed block shown in FIG. 4 can be formed. * ♦ * * • · · · · · · · «t I * * · * r * * * * ·> t I« · «4 ··· 31 be arranged. With the feed block 31, the flow velocity of the flotation foam for the gas separation space 6 can be further increased to make the turbulence in the gas separation space 6 more effective. The feed block 31 may be, for example, round, oval or rectangular. With a shallow-shaped end of the feed block 31, the reject of the flotation cell can be controlled more uniformly than a stream directed along the wall 30 of the gas separation space 6, which further enhances turbulence in the gas separation space 6 and the separation of gas from the flotation foam.

To the plant 1 of Fig. 4 further includes a first Gasausleitblock 10, which is arranged at the upper part of the Gasabscheidezyklons 4, wherein the over the Gasausleitblock 10 separated from the Flotationsschäum gas can escape from the Gasabscheideraum 6 by gravity. Alternatively, in connection with the Gasausleitblock 10, a suppressor or a fan can be arranged to remove the separated from the flotation gas from the gas separation chamber 6.

In all of the embodiments set forth above, the flow containing flotation foam to be supplied to the gas separation space at an increased flow rate is controlled either against or along the walls defining the gas separation space, i. towards or along the structures delimiting the gas separation space above the possibly formed in the gas separation space 6

Liquid surface. However, it is possible that other structures may also be positioned in the gas separation space 6, for example in connection with the control element against which or at which flow along the flow of flotation foam supplied to the gas separation space 6 is either partially or fully controlled.

Destroying the gas bubbles contained in the flotation foam can be further enhanced by arranging sharp peaks, ridges or other elements or shapes effectively destroying the gas bubbles on the walls delimiting the gas separation space or on other structures located in the gas separation space in the protruding section.

In addition, it is also possible that special liquid jets are directed into the gas separation space, such as water jets, to enhance the destruction of gas bubbles present in the flotation foam.

Those skilled in the art will appreciate that the basic idea of the invention can be implemented in many ways in the development of the technique. The invention and its embodiments are thus not limited to the examples described above, but may vary within the scope of the claims. It is therefore clear that the pump 2 can also be used in the gas separation plant 1 according to FIG. 4 for bringing about an increased flow velocity for the flotation foam -28- * * * * ♦ ····· «-28- * * * ♦ ·· ··· «

* · Can. After the solution, separation and removal of gas, such as air, from the flotation foam, other than in a recycling paper application, can also be realized in other flotation applications, such as, for example, the mineralization or the treatment of effluents.

Claims (19)

DR. FERDINAND GIBLER DR DR. WOLFGANG POTH Austrian and European Patent and Trademark Attorneys GIBLER & POTH PATENTANWÄLTE 33079 / ab Claims 1. A gas separation plant (1) for separating gas from flotation foam, the plant (1) at least a gas separation space (6) and in the gas separation space (6) at least part of the gas contained in the flotation foam is deposited by destroying gas bubbles in the flotation foam from the flotation foam in such a way, and wherein one with an increased flow rate in the gas separation space (6) zuzuführender, Flotationsschaum containing stream is controlled against at least one or along at least one of the gas separation (6) delimiting construction {5, 18, 30} or arranged in Gasabscheideraum (6) construction, characterized in that in Gasabscheideraum (6) or in its context at least one the flow direction of the flotation foam-containing stream controlling element (8, 16, 31) for controlling the flotation foam-containing stream against the or on the gas separation (6) delimiting structure (5, 18, 30) or arranged in Gasabscheideraum (6) arranged construction for destroying gas bubbles. 30 30 • · * I • · * · * · 2. Gasabscheideanlage according to claim 1, characterized in that the Gasabscheideanlage (1) is arranged in the vertical direction below a deinking process, wherein the increased flow rate of the flotation foam contained stream is arranged to be accomplished by the action of potential energy, by the height difference between the Deinkprozess and the gas separation plant (1) is achieved. 3. Gasabscheideanlage (1) according to claim 1, characterized in that the Gasabscheideanlage (1) at least one pressure supply (2) to achieve an increased flow velocity for the flotation containing stream. 4. Gasabscheideanlage (1) according to any one of the preceding claims, characterized in that the Gasabscheideanlage (1) a Gasabscheidekammer (4), whose one or more walls (5) and upper end (5 ') for limiting the Gasabscheideraums (6) are arranged. 5. Gasabscheideanlage (1) according to claim 4, characterized in that the direction of flow of the flotation containing flow-controlling element is a in the Gasabscheideraura (6) positioned nozzle plate, on the nozzles for controlling the flotation containing stream against the gas separation space (6) limiting Structures are arranged. 6. Gasabscheideanlage (1) according to one of claims 1 to 3, characterized in that the Gasabscheideanlage (1) a Gasabscheidebehälter (17), whose one or more walls (18) and ends (19) for limiting the Gasabscheideraums (6) are arranged. 7. Gasabscheideanlage according to claim 6, characterized in that the flow direction of the flotation containing flow-controlling element is a in the gas separation chamber (6) positioned nozzle (16). 8. Gasabscheideanlage (1) according to any one of the preceding claims, characterized in that the Gasabscheideanlage (1) a Gasabscheidezyklon (26), whose one wall (30) and upper end (30 ') for limiting the Gasabscheideraums (6) are arranged , 9. Gasabscheideanlage (1) according to claim 8, characterized in that the flow direction of the flotation containing flow-controlling element at the flank of a 32 32 * * »« ·· ♦♦ 9 ** * * * · · · · · · · * * Stream in the Gasabscheideraum (6) in a spiral rotational movement along the Gasabscheideraum (6) bounding wall (30). 10. Gasabscheideanlage (1) according to any one of the preceding claims, characterized in that the plant (1) further includes at least a first Gasausleitblock (10) which is connected to remove the separated from the flotation gas from the Gasabscheideraum (6) at the suppression , 11. Gasabscheideanlage (1) according to claim 10, characterized in that the plant (1) at least one control loop for regulating the in the gas separation chamber (6) to be formed vacuum levels heard. 12. Gasabscheideanlage (1) according to any one of claims 3 to 10, characterized in that the system (1) further at least one connected to negative second Gasausleitblock (12) in a pressure supply (2) for removing the separated from the flotation gas from the Inside the pressure supply (2) belongs. 13. Gasabscheideanlage (1) according to any one of the preceding claims, • · • · ······ Characterized in that the flow containing flotation foam for feeding at a speed of 1 to 10 m / s against or along the construction delimiting the gas separation space (6) (5, 18, 30) or arranged in Gasabscheideraum (6) construction is arranged. 14. Gasabscheideanlage (1) according to any one of the preceding claims, characterized in that the flotation containing stream for supplying against the gas separation space (6) delimiting construction (5, 18) or in Gasabscheideraum (6) arranged construction at an angle in the angular range ± 45 ° with respect to the rectangular direction of the stated construction. 15. A process for separating gas from flotation foam, wherein in the flotation foam process, at least part of the gas contained in the flotation foam is deposited in a gas separation space (6) of a gas separation plant (1) by destroying gas bubbles in the flotation foam, and wherein a flotation foam containing stream having an increased flow velocity is supplied to at least one or along at least one construction delimiting the gas separation space (6) or in the gas separation space (6) for destroying gas bubbles in the flotation foam. characterized in that the flow containing the flotation foam is arranged against or along a construction delimiting the gas separation space (6) (5, 18, 30) or arranged in the gas separation space (6) with at least one or in the context of the gas separation space (6) Flow direction of the flotation foam containing flow controlling element (8, 16, 31) is controlled. 16. The method according to claim 15, characterized in that the flotation foam at a flow rate of 1 to 10 m / s against at least one or along at least one of the gas separation space (6) limiting construction (5, 18, 30) or in Gasabscheideraum (6). arranged structure for destroying gas bubbles in the flotation foam is supplied. 17. The method according to any one of claims 15 or 16, characterized in that the Gasabscheideanlage (1) comprises a Gasabscheidekammer (4) or a Gasabscheidebehälter (17) and that the Flotationsschaum containing stream against one or more walls (5) of the Gasabscheideraum ( 6) delimiting Gasabscheidekammer (4) or against one or more walls (18) of the gas separation vessel (17) at an angle in the angular range ± 45 ° with respect to the rectangular direction of the said wall (5, 18) is supplied. 35 »« • · 35 »« • · »» · · L 18. The method according to any one of claims 15 or 16, characterized in that the Gasabscheideanlage (1) comprises a Gasabscheidezyklon (26) and that the flotation containing stream in a spiral rotational movement along the wall (30) of the Gasabscheideraum (6) delimiting Gasabscheidezyklons (26) is supplied. 19. The method according to any one of claims 15 to 18, characterized in that in the gas separation chamber (6) suppressor for removing the separated from the flotation gas from the Gasabscheideraum (6) is arranged with negative pressure.