CA2133958A1

CA2133958A1 - Procedure and means for processing liquids

Info

Publication number: CA2133958A1
Application number: CA 2133958
Authority: CA
Inventors: Viljo Jarvenpaa
Original assignee: Individual
Current assignee: Wiser Oy
Priority date: 1992-04-21
Filing date: 1993-04-20
Publication date: 1993-10-28
Also published as: EP0637260A1; NO943966L; NO943966D0; WO1993020917A1; FI90397B; FI90397C; JPH07505571A; AU3954693A; FI921754A0

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention relates to a procedure and a means for processing liquids, such as for oxidizing, flotating or treating in other desired ways. In the method a liquid to be processed is conducted as an in-flow into a first volume. Dispersion liquid and the air/gas/liquid dissolved therein is conducted into said first volume or into a volume in the immediate adjacency therebelow for intermixing the liquid to be processed and the dispersion liquid containing air/gas/liquid. The mixed, processed liquid mixture containing bubbles is made into a suspension surface. At least part of the liquid to be processed is conducted as a suction flow into a pump. air/gas/liquid is drawn with the pump as a flow into the suction flow, whereby the air/gas/liquid at a pressure generated by the pump is dissolved in the pump and in the discharge side thereof into the circulation flow, reacting possibly with reactable components in the circulation flow, reacting possibly with reactable components in the circulation flow. At least part of the processed circulation flow is returned with the pump into the liquid to be processed.

Description

-``YO 93/20917 2 1 3 3 ~ ~ 8 Pcr/FI93!00l62 Procedure and means for processing liquids S The present invention relates to a procedure for processing liquids, such as for oxidizing, flotating, or processing in other ways, in which procedure (a) a liquid tQ be processed is conducted as an in-flow into a first volume, 10 (b) a dispersion liquid and air / gas / liquid dissolved therein are conducted in~o said first volume or into a volume in the immediate adjacency therebdow for intermixing the liquid to be processed and the air / gas / liquid containingdispersion liquid, and 15 (c) the mixed, processed liq ud mixture containing bubbles is made into an upward modon, whereby the impurides are rapidly accumulated into a suspen-sion surface.

The invention also rehtes to a means for treadng, such as for oxidiziug, flotadng, 20 or processing in some other desired way liquids, with which means (a) a liquid to be processed is conducted as an in-flow into a first volume, (b) a dispersion liquid and air / gas / liquid dissolved therein are conducted 25 into said first volume or into a volume in the immediate adjacency therebelowfor intermL~ing the liquid to be processed and the air / gas / liq~ud containingdispersion liquid, and (c) the mi~ced, treated liquid mixnlre contairling bubbles is made into an upward 30 motion, whereby the impurides are accumulated into a suspension surface.

ln a variety of industrial applicadons, endeavours have been made to process :
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lo 93/20917 2 1 ~ 3 9 ~ 8 PCr/Flg3/00162 liquids chernically, to carry out chernical reactions, to circulate a liquid solution, to flotate solid components out of a liquid, to mix gases in a liquid into a homo-geneous rnixture, and/or rmix liquids with a liquid into a homogeneous mixture, as well as to carry out the above reactions at desired pressures.

Processing several liquuds is, however, difficult and somedmes even impossible because in ordinary condidons, i.e. at a standard pressure they cannot be made to mix. Onc of such wastc solutions is e.g. emulgated oil in water. Highly fine oil in an alkaline soludon is near-impossible to separate without lowering the pH of10 the soludon e.g. below 5. Hereby, the endre liquid mi~ture cannot usually be used any longer for the original purpose. As an example can be mendoned car washing liquid or water, into which oils are dissolved into an emulsion. Air can-not be mixed in such water because the air is not sufficicntly dissolved therein.
On the other hand, gas is known to be dissolved in a liq ud directly in compari-15 son with the pressure. Thus, increasing the prcssure in a gas and liq ud mi~ureenables multiple gas dissoludon in comparison with the norrnal atmospheric pressure.

In general, the liquids may contain difficult components and solid agents which 20 should be separated therefrom, in pardcular if the liquuds are pumped. The pumps will other-~nse wear and may be blocked. Endeavours have usually been made to eliminate the problems like these using a filter on the sucdon side of the pump. It depends on the qualiy and quandy of the solid agents, how well said filter operates and how long it is kept open. Cleaning filters condnuously is 25 not sensible, either. Therre are instances also in industrial applicadons in which no method is available for pumping liquids because the impurities contained in the liquid block all generally known and used filters.

30 Circuladng a liquid in a container into a reacdon target and back causes in several cases great difEiculdes. One of the problems is e.g. how to get the liquid quandy in the entire container mixed uniforrnly, how to bring the entire liquid , , ; -.; . . ~ .......... -.; , . .

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/0 93/20917 2 13 ~ ~ ~ 8 Pcr/Fls3/ool62 into a rcaction target and to get the entire liquid amount mixed unth a reactingcomponent. In a continuous process, difficulties arise in how to ensure the homo-geneity of the discharging liquid and as great purity as possible from e.g. solid agents. Therefore, e.g. in the industry so called batch processes exist for produc-5 ing a homogeneous product. Even in such cases it is customaly to filter theproduc~

In a number of industrial ~pplications adding a reacting agent into a liquid in a container has lead into a great number of difficulties because adding the reac~g10 agent should be accomplished as an addition of appropriate amount and suffi-ciently rnixed.
, An objcct of the invendon is to provide an improvement in methods and means currently known in the art for processing liquids.
A more detailed aim of the invention is to providc a method and a means which is particularly well appropriate e.g. for oxidizing, flotating or processing liquids in another desired method.

20 The aims of the invention are achieved by means of a method which is charac-terized in that in thc method ':
(d) at least part of the liquid to be processed is conducted as a suction flow into apump, . , (e) with said pump air / gas / liquid is drawn as a flow into a suction flow, whereby in the pressure generated by said pump the air / gas / liquid is dis-solved in said pump and on the discharge side thereof into a circulating flow, ;
possibly reacting with the reactable components in said circulaticn flow, and (f) with said pump at least part of the circulating flow processed in step (e) is returned to the liquid to be processed.

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The means according to the irNention is characterized in that the mcans is provided with a suction system for conducting at least part of the liquid to be processed as a sucdon ~o~ into a pump, that said pump has been arranged to draw air / gas / liquid as a flow into a sucdon flow so that in the pressure 5 caused by said purnp the air / gas / liqjuid is dissolved in said pump, and on the discharge side thereof, into a circuladon flow, possibly reacting with the reactable components in said circuladon now, and that said pump has been arranged to return at least part of the processed circulating ~ow into the liquid to be proc-essed.
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According to the basic idea of the invendon, the liquid to be processed can be brought into tubular circuladon from a container when the sucdon point is on the so-.called clean side of the pump, into the sucdon opening whereof a re- ~
ql~isite component is fed controlledly, in addition to the liquid to be processed, ~ - -15 such as reducing or o~idizing gas / liquid, whereafter the components of the dis-char8e sido, entered in the pmnp, are allowed to react / dissolve at a controlled pressure with themselves before being returned through a dispersing noz~le into a solution in the container to be reacted / circulated further while part of thesoludon is discharged from the circuladon cycle e.g. in an amount equivalent to -20 the feed out or for further reacdon.
~. ~ `;"'''`'' With the procedure and means of the invendon a plurality of significant advan~
tages are achieved. With the design of the invendon extremely dif~cult soludons or liquid misturos can be processed and chernically impure mixtures purified in 25 a desired manner. In the design of the invendon, purified soludon enters the liquid circuladon and pressurizadon by which the operability of the purnp is guwnteed. In a preferred embodiment of the invention the free pressurizadon control and use of a dispersion nozzle yields great opportunides to accomplish chemical reacdoDs in a drawn-in soludon.
The invention is described in detail referring to some preferred embodiments of the invendon presented in the figures of the drawings, whereto the invention is :1''Z : ~ ; ", ", ,., . ~ . , . .. , ., , . . . ~ . , ~o 93/20917 ~! 1 3 3 9 ~ 8 PCr/F193/00162 not, however, intended to be exclusively confined.

Fig. 1 presents an advantageous embodiment of a means design used in the method of the invendon as a schematical cross-section image.
Fig. 2 presents an embodiment of a second preferred means design used in the method of the invendon as a schemadcal cross-section image.

In the embodiment of Fig. 1 the means used in the procedure of the invention : 10 is in general indicated by reference numeral 10. The means 10 is provided with a cover 11 through which a pipe 12 leads for conducting in a liquid to be proc-essed in the folm of an in-90w A. The upper surface a of the liq~ud is usually preferably in the proximiy of the cover 11. The lower end of the pipe 12 is provided with a flange 13, from the outer edge of which rises a cone 14, and itsextensions 14a so that the upper edge of the extensiop 14a of the cone 14 re-mains sufficiently below the liquid surface a. In the embodiment of Fig. 1 the extension 14a of the cone 14 is preferably a cylindrical surface. The pipe 12 issurrounded by a second pipe 15, this being preferably a concentric pipe. The pipe 15 actends lower than the upper edge of the extension 14a of the cone 14 20 into the liquid. In the adjacency of the upper edge of the extension 14a of the cone 14 is placed a perforated ring 16, extending to the pipe 15. The perforatedring 16 is preferably a sheet metal ring. The perforated ring 16 has been sup-ported both to the extension 14a of the cone 14 and to the pipe 15. In the annular space defined by the pipe 12 and the flange 13 therebelow has been 25 placed the suction part of the suction pipe 18 of the pump 17, being preferably a suction ring 18, in order to equalize the suction in the liquid space. The liquid flow flowing in the suction pipe 18 is indicated by K

In the suction aperture of the pump 17, a second suction pipe 20 with control 30 valves 20a has been connected so that the suction 90w B entering along the pipe 20 can be controlled as desired. After the pump 17 is positioned a channel 21 which can be 4uite long. The channel 21 ends in an equalizauon chamber 22, : . . . .

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vo 93/20~17 2 1 3 3 9 ~ 8 Pcr/FI93/00l62 with which e.g. extra, non~issolved gas can be removed if necessary or if desired. The liquid ~ow continues its flow from the channel 21 along a pipe 23 either back into the circula~ion along the pipe 24 as a flow K or preferably con-trolled by a liquid surface height mor~itor 25, through a control valve 24a into the 5 discharge flow C. If desired, a control valve or a potential back pressure valve 29 can be inserted within the suction pipe 18 with which a vacuum pressure of desired rnagnitude can be provided on the suction side of the pump 17 in order to produce a desired ~ow B.

10 The liquid / so1ution flowing back in the pipe 24 is pressured / controlled to be appropriate in pressure with a dispersion nozzle 26, positioned preferably at the lower mouth of the pipe 12 either thereabove or therebelow. When new liquid / solution to be processed is fed into the space provided by pipe 12 as aflow A, the soludon / liquid to be processed may contain desired mix compo-15 nents or additions so that the soludon / dissolved gas discharging from thedispersion nozZ:le is immediately made to mix / react with the liquid flow A to be processed. The pressure provided by the dispersion nozzle 26 can be control~
led e.g. by counterpressure, in the present embodirment by mearls of compressed air b of the control ~ralve 27.
In the design according to the invendon, air / gas / liqud can be thus drawn;
into the pump 17 through a suction connector provided with a control valve 20a as a flow B, from which e.g. the air is released in a volume after the dispersion noz~le 26 in an amount which is in proportion to the pressure as an extremely 25 fine, nearly molecular, dispersion, usually gathering into greater bubbles tending at the same time to adhere to the solid matter particies in the liquid and/or inthe liquid impurides. The impurides contained in the liquid to be processed become thus flotated, i.e. they arise onto the surface of the liquid to be pro-cessed. The truly heavy solid matter components go downwards past the disper-30 sion nozzle 26. The gaseous bubbles and impurity components attached theretorise towards thc surface at their own speed. The impurity components rising to the surface form foam 28 on the surface of the liquid, which is removed as a ...... ., ,, .. . .... , . ~ -.- . ~ .. . ~

NO !~3/~0917 2 1 3 3 ~ ~ 8 PCI~/~193/00162 flow D in a manner known in itself in the a~.~

The embodiment in Fig. 2 is othe~wise similar to that in Fig. 1, except that thecover 11 in the embodiment as shown in Fig. 2 is connected to a container 30, 5 the size thereof being selected according to the cone 14 used therein. Hereby,the truly hea~y solid matter components fall onto the bottom of the container 30.
Circulation flow K discharging as uniformly as possible in all directions from the dispersion nozzle 26 is extremely great in speed. Into the discharging circulation now K an inflow A is mixcd aftcr the dispersion nozzle 26. The flows K and 10 A constitute a flow P which is directed upwards in the space between the container 30 and the extension 14a of the cone 14 at a desired speed. Said liquid flow F is equalized with the aid of a perforated ring 16, whereby the magnitude of the flow G directed downwards through the perforated ring 16 is so small that the solid matter within the air bubbles will not follow along with the flow.
15 Therethrough the liquid entering the suction ring 19 can be purified from solid agents. The discharge point of the purified liquid is indicated by E, and it is drawn from the space between the pipes 12 and 15.

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In some instances, the flow C can be conducted into a further process such as 20 into a wet washcr, whereby the dissolved oxygen / chemicals contained in the now C react to / wash gases and dusts as desired, returDing into the circulationwater container 30 in the form of ~ow A or as part thereof, containing ~npur-ities which are purified with the means design 10 according to the invention.
Hereby, liquid may have to be removed from the circulation as a flow E, being 25 drawn from the annular spacc between the pipes 12 and 15, but said liquid to be removed has, however, undergone a purification process similar to the flow K' of the liquid entering the pump 17.

Also in the embodiment shown in Fig. 1, the nOw C may similarly be conducted 30 into afurtherprocess.

The design of the invention can be used for several purposes: for instance, for , :',. '.
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~Yvo 93/20917 213 3 9 ~ 8 pcr/~l93/oo162 sulphur removal from flue gases, in which the flow C enters the washer, therein dissolving into itself e.g. SO2 gas, that is, sulphur dio~de. This kind of dissolved sulp~ur dioxide becomes oxidized with the oxygen prevailing in the flow B
drawn into the pump 17 into sulphur trioxide SO3, and further, into sulphuric 5 acid because an aqueous solution is in question. Hereby, part of the flow C may be carried directly into further processing of sulphuric acid, where the sulphuric acid can, if needed, be processed or concentrated in a desired manner. Flow C, re-entering totally or partly the washer, contains no SO2 gas in dissolved form and it is therefore prepared to dissolve again new sulphur dioxide in itself.
The design according to the invendon can be used for flotadon e.g. in paper industry in msmufacturing recycled paper in the flotadon process of black prindng ink. The residual waters contain syanides, phenols, hurnus, etc., which can be oxidized by appropriate chemical addidons in the feed flow A The iron 15 in the drinking waters is in ferro form, which with the design of the invendon can be eliminated easily utilizing appropriauly the pH range in the feeding A. The invendon is in no way cridcal regarding the flow B, but flow B can be any gas / chemical, because of which the design of the invention has a wide usage and applicatdon rsmge.
ln the foregoing, orlly a few advantageous embodiments of the invendorl, and it,is obvious to a person sldlled in the art that a plurality of modificadons can be made therein within the scope of the invendve idea presented in the accompany-ing claims.

Claims

1. A procedure for processing liquids, such as for oxidizing, flotating, or process-ing in other ways, in which procedure (a) a liquid to be processed is conducted as an in-flow (A) into a first volume (12), (b) a dispersion liquid and air / gas / liquid dissolved therein is conducted into said first volume (12) or into a volume in the immediate adjacency therebelow for intermixing the liquid to be processed and the air / gas / liquid containingdispersion liquid, and (e) the mixed, processed liquid mixture containing bubbles is made into an upward motion, whereby the impurities are accumulated into a suspension surface (28), characterized in that in the method (d) at least part of the liquid to be processed is conducted as a suction flow (K') into a pump (17), (e) with said pump (17) air / gas / liquid is drawn as a flow (B) into the suction flow (K'), whereby the air / gas / liquid in the pressure generated by said pump (17) is dissolved in said pump (17) and on the discharge side thereof, intocirculation flow (K), and possibly reacts with reactable components in said cir-culation flow (K), and (f) at least part of the circulation flow (K) processed in the procedure step (e) is returned with said pump (17) from the processed circulation flow (K) into theliquid to be processed.

2. Procedure according to claim 1, characterized in that into the circulation flow (K) processed in step (e), the in-flow (A) is mixed for forming a flow (F), saidflow (F) being conducted upward at desired speed.

3. Procedure according to claim 2, characterized in that said upward conducted flow (F) is conducted at a smaller speed as a flow (G) downwards back into the suction flow (K') and/or into the outflow (E).

4. Procedure according to claim 3, characterized in that the flow (G) is equal-ized with the aid of a perforated ring (16).

5. Method according to any one of claims 1 to 4, characterized in that the circulation flow (K) returned into the liquid processed in step (f) is conductedinto the liquid to be processed through a dispersion nozzle (26).

6. Method according to claim 5, characterized in that the pressure provided by the dispersion nozzle (26) is controlled.

7. Method according to claim 6, characterized in that the pressure provided by the dispersion nozzle (26) is controlled by means of compressed air flow (b).

8. Method according to any one of claims 1 to 7, characterized in that part of the circulation flow (K) is conducted into a discharge flow (C).

9. A Method according to claim 8, characterized in that the discharge flow (C) is adjusted being controlled by a control valve (24) and a surface height monitoring means (25).

10. Method according to claim 8 or 9, characterized in that the discharge flow (C) is conducted into a wet washer from which the discharge flow (C) returns in the form of in-flow (A) or as part thereof.

11. Method according to claim 8 or 9, characterized in that part of the discharge flow (C) is conducted directly into sulphuric acid to be processed further.

12. Method according to any one of claims 1 to 11, characterized in that the flow (B) of air / gas / liquid is controlled with the aid of a control valve (20a).

13. Method according to claim 12, characterized in that a control valve /
potential back pressure valve (29) is positioned in the suction flow (K') for controlling a desired underpressure in the suction side of the pump (17), in order to provide a desired air / gas / liquid flow (B).

14. A means for processing liquids, such as for oxidizing, notating, or processing in any other desired way, with which means (a) a liquid to be processed is conducted as an in-flow (A) into a first volume (12), (b) a dispersion liquid and the air / gas / liquid dissolved therein are conducted into said first volume (12) or into a volume in the immediate adjacency there-below for intermixing the liquid to be processed and the air / gas / liquid containing dispersion liquid, and (c) the mixed, processed liquid mixture containing bubbles is made into an upward motion, whereby the impurities are gathered into a suspension surface (28), characterized in that the means (10) is provided with a suction system (18,19) for conducting at least part of the liquid to be processed as a suction flow (K') into a pump (17), that said pump (17) has been disposed to draw air / gas / liquid asa now (B) into the suction flow (K'), whereby in the pressure generated by said pump (17) the air / gas / liquid is dissolved within said pump (17) and on the discharge side thereof, into the circulation flow (K), and may react with reactable components in said circulation flow (K), and that said pump (17) has been arranged to return at least part of the processed circulation flow (K) into the liquid to be processed.

15. Means according to claim 14, characterized in that the means (10) is provided with a dispensing nozzle (26) for conducting the circulation flow (K) into the liquid to be processed.

16. Means according to claim 15, characterized in that the pressure yielded by the dispensing nozzle (26) can be controlled.

17. Means according to claim 16, characterized in that a control valve (27) has been provided to control the flow of compressed air (b).

18. Means according to any one of claims 14 to 17, characterized in that in the means (10) a flow equalizing means (16) is provided, arranged to equalize and conduct the upward flow (F) formed by said circulation flow (K) and said in-feedflow (A) to become a flow G) flowing at a lower speed downwards.

19. Means according to and one of claims 14 to 18, characterized in that the means (10) is provided with a discharge flow connector for conducting part of the circulation now (K) into discharge flow (C).

20. Means according to claim 19, characterized in that the discharge flow connector is provided with a control valve (24a).

21. Means according to any one of claims 14 to 20, characterized in that the means (10) is provided with an outflow connector (E) for the purified liquid.

22. Means according to any one of claims 14 to 21, characterized in that the suction system (18,19) consists of a suction pipe (18) and a suction ring (19) connected thereto.

23. Means according to any one of claims 14 to 22, characterized in that the suction system (18,19) is provided with a control valve / a potential back pres-sure valve (29) for controlling a desired underpressure on the suction side of the pump (17).

24. Means according to any one of claims 14 to 23, characterized in that the means (10) is provided with a connector (20) for conducting the flow (B) of air / gas / liquid into the pump (17).

25. Moans according to claim 24, characterized in that the connector (20) is provided with a control valve (20a).

26. Means according to any one of claims 14 to 25, characterized in that the first volume (12) is composed of a tubular connector (12), the lower end thereofbeing provided with a flange (13), and that the ouer edge of said flange (13) isprovided with an ascending cone (14) with extensions (14a).

27. Means according to claim 26, characterized in that the pipe (12) is sur-rounded by another pipe (15), extending lower than the upper edge of the extension (14a) of the cone (14) into the liquid.

28. Means according to any one of claims 18 to 27, characterized in that said flow equalizing part (16) is a perforated ring positioned to the adjacency of the upper edge of the extension (14a) of the cone (14) and extending to the pipe (15).

29. Means according to any one of claims 22 to 28, characterized in that the suction ring (19) has been placed within an annular space defined by the pipe (12) and the flange (13) in the lower end thereof, and the cone (14).

30. Means according to any one of claims 14 to 29, characterized in that the channel (21) of the discharge side of the pump (17) is provided with an equaliz-ation chamber (22) for discharging extra, non-dissolved gas.