DE102004026477A1 - Liquid mixing tank or dissolver, for e.g. mixing dialysis concentrate, includes jet agitation system for recirculated fluids and solids - Google Patents

Abstract

The equipment (10) mixes fluids (12) in a tank (14) using a recirculation system (34, 40, 42, 44, 54). This takes fluid from the tank and returns it via a closed-circuit, using a centrifugal pump (54). An extraction opening (30) is located at the lowest point in the tank. Fluid nozzles (or other directional units) inject the fluid back into the tank in various directions, e.g. horizontally and tangential to its circular wall, or in a vertical direction, parallel to the wall. Flow baffles are included in the vessel. Additional fluid inlet and outlet connections are provided (36, 38). Solids, e.g. granular material, powder and/or dust may be fed into the recirculation system. Several jets (46, 48, 50) re-introduce recirculated fluid into the tank. An independent claim is included for corresponding equipment.

Description

The Invention relates to a mixing device for mixing fluids, with a container device for receiving at least one fluid to be mixed and at least a mixing device for the fluid. Furthermore, the invention relates to a method for mixing of fluids, as well as the use of the proposed method or the proposed device.

The Mixing substances is a very common practice Process not only for industrial, especially chemical processes is applied, but also in Household often perform is, such as cooking and baking.

When substances to be mixed with each other are not just substances in the same state of aggregation (for example liquids with liquids or solids with solids), but also substances in different states of matter (for example liquids with solids). It can also happen that In the course of a mixing process, the state of aggregation of a the substances used changed (e.g., resolution of solids, for example salts, in a liquid or physical solution of gases in a liquid).

at previously known mixing devices become common one or more stirring tools into the substance to be mixed, which is in a container, introduced and moved in this, leaving the corresponding substance or the corresponding substances by the introduced mechanical Work with each other are mixed. As stirring tools, for example Mixing blades, stirring fish, Mixed whims (especially for Liquids), Dough hook (in particular special for doughy substances or solids) or propellors (especially for gases) used.

These However, known mixing methods also have disadvantages. Especially it is usually required that the stirring tools powered by its own engine. Thus, for the filling or Emptying of the mixing container to provide separate drive devices, which corresponds to the device consuming, more expensive, more voluminous, heavier and more prone to error power.

Furthermore There is often a not inconsiderable abrasion on the stirrer whose Material finally in the mixed together substances finds. Correspondingly often is also the stirring tool to renew.

Also the mixing effect of known mixing devices is often not optimal. So it is a well-known phenomenon that it is in fluid flow of the stirring tool usually comes to a bad mixing. For example, if solids, like salts, in a liquid dissolve are not uncommon, that solid particles in the flow of the stirring tools accumulate and dissolve there or only after a very long time.

Of the Invention is based on the object, a mixing device for fluids, or to propose a method for mixing fluids, which the Problems encountered with known devices or methods at least partially eliminated, or at least partially reduced. Farther It is an object of the invention, particularly advantageous uses for the proposed device, or show the proposed method. In particular, it is the object of the invention to provide a method or to propose a device with which a particularly good Mixing effect is achievable. Furthermore, the device or the procedure relatively simple and inexpensive from the construction, the operation and from the maintenance sensitivity.

A Mixing device according to claim 1 and / or a method according to claim 14 solve the task. Furthermore, those proposed according to claim 18 and 19 Uses particularly advantageous. The subclaims give favorable Further education. In addition, all fall within the scope of the invention Combinations of at least two in the description, the drawing and / or the claims disclosed features. For range specifications, all intermediate values are to be regarded as co-disclosed.

It is proposed to develop a mixing device for mixing fluids, with a container device for receiving at least one fluid to be mixed and at least one mixing device for the fluid in that at least one mixing device is designed as a circulation device, which takes fluid from the container device and through at least one essentially closed circuit returns to the container device. This makes it possible to arrange the mixing tool outside the container device. This possibly makes easier access to components of the mixing device, such as the drive unit for the Umwälzwerkzeug, which can allow a simplified structure and a simplified maintenance. Of course, it is conceivable that the container device consists of several individual containers or a Container also has a plurality of container compartments. If necessary, the recycling can then take place with the intermediate storage of other containers or container parts, until finally a return to the starting container takes place. Furthermore, the proposed structure makes it possible for the circulation device to also assume a further task - which will be discussed in more detail below - so that a further simplification of the overall system can result. In addition, the proposed structure allows a particularly good mixing effect can be realized. Under fluids in the present case, in particular to gases and / or liquids to think. However, it is also possible and useful that the mixing device mixes, for example, a fluid to which a certain proportion of solids, in particular of solids in the form of granular substances, powders, dusts and / or granules is added. This addition can be carried out in particular for the purpose of dissolving these substances (for example dissolving salts in a liquid such as water). The proposed device is suitable for essentially any type of liquid (different densities and viscosities), especially for aqueous solutions. The density of the liquid to be mixed may, for example, in the range between 0.5 g / cm ³ to 3 g / cm ³ , preferably in the range between 0.8 g / cm ³ and 2 g / cm ³ , particularly preferably in the range of 1 g / cm ³ to 1.5 g / cm ³ .

Usually is for at least one circulating device provided at least one pump, which causes the circulation of the fluid. Preferably For this purpose, a centrifugal pump is used, which is usually a relative simple construction, a relative freedom from interference during operation and through distinguish relatively high throughput rates.

From It is advantageous if at least one circulating device has at least one, Having preferably at the lowest point of the container device removal opening. By this arrangement, it is particularly possible that the removal opening for the circulating device also for the removal of liquid, optionally also for the substantially complete removal of the mixed Liquid, can serve. Also for the purpose of circulation, this arrangement of Advantage, since it - for example when it comes to solving of salts in an aqueous solution goes - liquid parts with a high salt content, and therefore with a high density, the migrate downwards due to gravity, can be transported upwards via the circulation device, and so a particularly good mixing can be promoted.

Preferably has at least one circulating device at least one fluid returning device, Preferably, a plurality of fluid returning means. These can be simple discharge openings or pipe ends act. Usually these are arranged so that these below the normal filling level of the container device lie. In particular, by the number of nozzles one possible Good compromise between simple design, high injection speed (less injectors), one possible high liquid flow rate and an optionally better mixing effect by the return of the Fluids are found at different locations (multiple nozzles), where Of course, with this optimization, other parameters considered can be. As useful has a number of nozzles from two, three, four or five fluid returning Facilities proved.

Is possible it too, that the fluid recirculating Facilities along the size of the container device and / or re their height arranged offset from each other. In other words, the Arrangements are arranged so that they are not along a Line are located. As a result, a further improved mixing effect is possible.

at It has proven to be advantageous, if at least a fluid return device the fluid in a substantially horizontal and parallel to the Wall of the container device directed Gives direction. This type of injection can be a Whirl in the container device train for a particularly good mixing of the fluid can provide.

Likewise, it has proved to be advantageous if at least one fluid return device emits the fluid in a direction directed transversely to the horizontal substantially parallel to the wall of the container device. This too can lead to a particularly good mixing of the fluid. Both mentioned arrangements can also be advantageously combined with each other. In particular, it makes sense if one of the fluid-returning devices outputs the fluid transversely to the horizontal, while the remaining fluid-return devices output the fluid substantially horizontally. As a result, a vortex can be formed, which is disturbed by the additionally induced transverse component in an advantageous manner. In particular, if the injection running transversely to the horizontal takes place through the lowest fluid returning device, it may be possible for solids introduced into the fluid (eg not yet dissolved salts) to be kept away from a downwardly disposed removal opening for the circulating device, so that the solids do not , Or in a significantly reduced amount can enter the pump circuit, and so damage or Ver Wear of the pump can be largely avoided. It is also possible that settling of the solids can be avoided, so that a further improved mixing can result. As "transverse" any angle between 0 ° and 360 ° is conceivable, in particular a 90 ° transversely to the horizontal upward liquid ejection conceivable.

When It has proven advantageous if at least one fluid return device as an injection nozzle is trained. Such an injection nozzle, the fluid in the form of a Eject jets, which proved to be particularly advantageous for the mixing process Has.

From It is also advantageous if the container means a substantially has a round cross-section. In this case, especially for a thorough mixing advantageous flow conditions will be realized. In particular, a vertebra education allows or promoted become.

Farther It may prove advantageous if a container device at least one flow obstacle having. Such a flow obstacle, for example, in the form of a arranged at a certain angle Flapper, can again for to ensure improved mixing. In order to possibly an accumulation solids behind the flow obstruction prevent, can at least parts of the flow obstacles movable become.

Especially Cheap it is furthermore, if at least one of at least one circulating device branching fluid removal device and / or fluid supply device is provided. In this case, it is possible to increase the number of in the container device to be provided openings to reduce. About that In addition, the pump in addition to the Umwälzwirkung for emptying or for filling the container device be used so that it is possible is to reduce the number of required drive units. Independently it is self-evident also possible, separate feeders or to provide removal devices, in particular for sampling can serve.

Farther It may prove advantageous to provide at least one Festkörpereinbringvorrichtung. This can, for example, as a simple "manhole", or possibly also as a lock device be formed, for example, a particularly high sterility of the container interior to be able to realize.

Is possible it thereby, that at least one Festkörpereinbringvorrichtung, in particular a solid-state introduction device for granular substances, Powder, dusts and / or granules, as arranged in at least one circulating device Addition agent executed is. This can be done, for example, by a Venturi nozzle device will be realized. As a result, in particular, the operation of the Mixing device for the operating staff are simplified, as it may not more is needed substances under application of physical Work first to a located in the upper region of the container device Filling opening too wear.

Further is a method of mixing fluids in which the mixture the fluid at least partially by a removal of fluid a container device and subsequent Return of the Fluids in the container device via at least one essentially closed circuit is proposed. The proposed method and the developments proposed in the subclaims have the advantages mentioned in connection with the mixing device in an analogous manner.

The proposed mixing device or the proposed method is particularly suitable to soluble Solids in a liquid dissolve.

Especially the device or the method is suitable for mixing to be used by dialysis concentrate. So far, dialysis concentrate in water solution transported to the dialysis centers. However, dialysis concentrate is usually 85% water, it can be used especially for larger dialysis centers prove more economical to use the dialysis concentrate on site Mix. In this case, it is only necessary, the dialysis salts to be supplied as solid. As a water supply can be a corresponding Processing plant to be installed on site. This allows in particular Transport costs are saved to a considerable extent. By the proposed device or the proposed method can be fast, easy, inexpensive and high quality Mixing done locally.

Further Advantages, features and details of the invention will become apparent the following description of preferred embodiments and by reference the drawing; this shows in:

1 a mixing device according to an embodiment of the invention in a lateral, schematic view;

2 a possible arrangement of injection nozzles in a mixing vessel in plan view;

3 : a part of the in 2 shown nozzle arrangement in a schematic view;

4 : a possible design of an injection nozzle in a lateral schematic view.

In 1 is a mixing plant 10 for mixing an aqueous solution 12 shown in a schematic view. The mixing plant 10 serves to generate a dialysis concentrate. For this purpose, purified water must be mixed with a special salt preparation in such a way that the salt is completely dissolved.

The mixing plant 10 consists of a container 14 , which has a filling volume of about 800 l in the present embodiment. In the upper area 18 of the container 14 is an opening in the form of a so-called manhole 16 provided, through which the salt preparation can be introduced into the purified water. The bottom of the container 12 is inclined at an angle of in the present case about 25 ° relative to the horizontal. In normal operation, the level is high 22 about 3/4 of the height of the container 14 , The level height 22 the aqueous solution 12 can through a sight glass 24 , which is in the present case in the form of a transparent plastic tube, are controlled from the outside. Of course, independently or additionally, a check of the filled volume by a suitable measuring instrument in the inlet or other facilities can be measured.

In the area below 28 of the container 14 are present three injectors 46 . 48 and 50 educated. At the bottom of the container 14 is still a funnel-shaped approach 26 arranged, which has an outlet opening 30 having. The funnel-shaped approach 26 and the outlet opening 30 are presently designed and arranged such that a substantially complete emptying of the container 14 over the outlet opening 30 is possible. Behind the outlet 30 there is a ball valve 32 , which can be controlled by hand, but also by, for example, electrical control. About a first hose 34 (Suction line) is that of the outlet opening 30 coming aqueous solution 12 a centrifugal pump 54 fed. The centrifugal pump 54 , which is driven in the present case by an electric motor with a maximum power consumption of 2.2 kW, has in the present embodiment, a capacity of about 800 liters per minute (with free outlet). The pump 54 promotes the aqueous solution 12 in the direction of a distributor 52 , At the distributor 52 are several ball valves 32 arranged, by means of which (by hand or by control signal regulated) the connection to one of the hoses 46 . 48 and 50 (Pressure lines), or to an output hose 36 can be opened. Additionally located on the suction side of the centrifugal pump 54 a filling hose 38 which also has a ball valve 32 with the first hose 34 can be connected.

In normal mixed operation, the ball valves 32 switched so that a closed circuit starting from the container 14 over the outlet opening 30 , the first hose 34 , the pump 54 , the distributor 52 as well as the hoses 40 . 42 . 44 and the associated injectors 46 . 48 . 50 back into the container 14 results. The output hose 36 as well as the single hose 38 are separated from the closed circuit.

By the operation of the pump 54 becomes the aqueous solution 12 transported through the circulation circuit and through the injectors 46 . 48 and 50 so in the container 14 aqueous solution 12 injected so that the latter is placed in a vortex-shaped, rotating motion, which ensures excellent mixing of the liquid 12 provides. The lower injection nozzle 4b is - at a container height of about 170 cm - at a height of about 20 cm (measured from the lowest point of the funnel-shaped approach 26 ) arranged. The middle injector 48 is located at a height of 30 cm, the upper injection nozzle is located at a height of about two-thirds of the container height, in this case at a height of about 120 cm. For the first hose 34 (Suction line) a hose with a diameter of 2 "is used for the second to fourth hose 40 . 42 . 44 (Pressure lines) hoses are used with a diameter of 1 1/4 '', which in the present case are under a pressure of 1.8 bar. Of course, other dimensions can be used. It is also possible that the hoses are at least partially replaced by rigid pipes.

For filling the container 14 with a liquid 12 become the ball valves 32 switched such that the outlet opening 30 locked, the filling hose 38 as well as the pressure hoses 40 . 42 . 44 are open against it. This allows the pump 54 as suction pump for filling the mixing plant 10 act. By a corresponding position of the ball valves 32 (Auslasföffnung 30 opened, pressure hoses 40 . 42 . 44 closed, discharge hose 36 opened) can the pump 54 In addition, also act as a discharge pump.

In the 2 and 3 becomes the location and orientation of the injectors 46 . 48 . 50 in the container 14 clarified.

2 represents a schematic plan view from above into the container interior. In the middle the container bottom is the funnel-shaped approach 26 with the outlet opening therein 30 to recognize. Furthermore, the arrangement of the lower injection nozzle 46 , the middle injector 48 and the upper injector 50 to recognize.

In 2 It is good to see that the first injector 46 ejecting the liquid emitted by it in a direction substantially parallel to the container wall 72 runs in a direction parallel to a diameter line 56 through the container 54 runs. In contrast, the middle injection nozzle 48 as well as the upper injection nozzle 50 arranged so that these are the liquid 12 in a direction that is substantially parallel to the container wall 72 and level to the ground.

In 3 is the in 2 indicated by a dashed line cutout area A again. In this illustration, it can be clearly seen that the outflow angle α of the lower nozzle 46 that by the outflow direction 58 the nozzle 46 and the flow direction 60 the agitated aqueous solution 12 is defined, in this case is about 90 °. However, this angle may take any angle between 0 ° and 360 °, in particular 15 °, 30 °, 45 °, 60 °, 75 °, 105 °, 120 °, 135 °, 150 °, 165 °, 180 °, 195 °, 210 °, 225 °, 240 °, 255 °, 270 °, 285 °, 300 °, 315 °, 330 °, 345 °.

In 4 Finally, one possible embodiment of an injection nozzle 46 for the described mixing plant 10 shown. In the illustrated injector 46 It can not just be a bottom injector 46 but also to a middle one 48 or upper injector 50 act. The injector 46 has a hose neck area 62 for connection with a hose. This can be formed for example as a thread or as slip resistance for pushing a hose. Furthermore, the injection nozzle 46 a threaded area 64 on which a fixing nut 66 can be screwed on. It is an annular flange 68 provided on which a sealing rubber 70 is arranged. The feed side 74 the injector 46 goes over an angled area 76 (in this case a bend of 90 °) in a discharge area 78 above. The discharge opening 80 is cut in an outflow angle β of present 30 °. This will ensure that the out of the injector 46 effluent liquid a certain directional bundling effect to the vessel wall 72 receives. This has an advantageous effect on the flow in the container 14 so that a better mixing effect results.

The distance between the discharge opening 80 and the container wall 72 in the present case is about 4 cm. It should be noted that the outflow angle β can assume any desired values between 0 ° and 90 °, in particular 20 °, 25 °, 35 °, 40 °, 45 ° or 50 °.

How out 4 it can be seen, the injection nozzle 46 thereby on the container wall 72 of the container 14 a mixing plant 14 be attached that the feed side 74 the injector 46 through a corresponding bore of the container wall 72 is inserted, and then a fastening nut is screwed and tightened. Thanks to the sealing rubber 70 , the ring flange 68 is provided, resulting in a dense arrangement.

For the described mixing plant 10 Of course, other dimensions and purposes are conceivable.

Claims (19)

Mixing device ( 10 ) for mixing fluids ( 12 ), with a container device ( 14 ) for receiving at least one fluid to be mixed ( 12 ) and at least one mixing device for the fluid, characterized in that at least one mixing device as a circulating device ( 34 . 40 . 42 . 44 . 54 ) is formed, the container means fluid ( 12 ) and through at least one substantially closed circuit in the container device ( 14 ). Mixing device according to claim 1, characterized in that at least one circulating device ( 34 . 40 . 42 . 44 . 54 ) at least one pump ( 54 ), preferably at least one centrifugal pump. Mixing device according to claim 1 or 2, characterized in that at least one circulating device ( 34 . 40 . 42 . 44 . 54 ) at least one, preferably at the lowest point of the container device ( 14 ) removal opening ( 30 ) having. Mixing device according to one of the preceding claims, characterized in that at least one circulating device ( 34 . 40 . 42 . 44 . 54 ) at least one fluid return device ( 46 . 48 . 50 ), preferably a plurality of fluid return devices ( 46 . 48 . 50 ), having. Mixing device according to one of the preceding claims, characterized in that the fluid return devices ( 46 . 48 . 50 ), along the circumference of the container device ( 14 ) and / or arranged offset relative to each other in height. Mixing device according to one of the preceding claims, characterized in that at least one fluid return device ( 48 . 50 ) the fluid in a substantially horizontal and parallel to the wall ( 72 ) of the container device ( 14 ) direction. Mixing device according to one of the preceding claims, characterized in that at least one fluid return device ( 46 ) the fluid in a transverse to the horizontal substantially parallel to the wall ( 72 ) of the container device ( 14 ) direction. Mixing device according to one of the preceding claims, characterized in that at least one fluid return device as injection nozzle ( 46 . 48 . 50 ) is trained. Mixing device according to one of the preceding claims, characterized by a container device ( 14 ) having a substantially round cross section, Mixing device according to one of the preceding claims, characterized in that a container device ( 14 ) has at least one flow obstacle, which is preferably designed to be movable. Mixing device according to one of the preceding claims, characterized by at least one of at least one circulating device ( 34 . 40 . 42 . 44 . 54 ) branching fluid removal device ( 36 ) and / or fluid supply device ( 38 ). Mixing device according to one of the preceding claims, characterized by at least one solids introduction device. Mixing device according to claim 12, characterized in that at least one Festkörpereinbringvorrichtung, in particular a Festkörpereinbringvorrichtung for granular substances, powders, dusts and / or granules, as in at least one circulating device ( 34 . 40 . 42 . 44 . 54 ) arranged addition means is executed. Method for mixing fluids, in which the mixture of the fluid ( 12 ) at least partially by a removal of fluid ( 12 ) from a container device ( 14 ) and subsequent recycling of the fluid ( 12 ) in the container device 14 via at least one substantially closed circuit ( 34 . 40 . 42 . 44 . 54 ) he follows. Process according to claim 14, characterized in that the recycled fluid ( 12 ) in the form of at least one, preferably more fluid jet ( 46 . 48 . 50 ) into the container device ( 14 ) is introduced. Method according to claim 14 or 15, characterized in that at least one fluid jet ( 48 . 50 ) substantially horizontally and parallel to the wall ( 72 ) of the container device ( 14 ) runs. Method according to one of claims 14 to 16, characterized in that at least one fluid jet ( 46 ) transverse to the horizontal, substantially parallel to the wall ( 72 ) of the container device ( 14 ) runs. Use of the method according to one of claims 14 to 17 and / or a device ( 10 ) according to one of claims 1 to 13 for dissolving soluble solids in a liquid ( 12 ). Use of the method according to one of claims 13 to 17 and / or a device ( 10 ), according to any one of claims 1 to 13, for the mixing of dialysis concentrate ( 12 ).