EP2566626B2 - Nozzle separator and method for diverting a solid phase from the nozzle separator - Google Patents

Description

The invention relates to a nozzle separator according to the preamble of claim 1 and a method according to the preamble of claim 6.

With regard to the preamble of claim 1, the US 4 286 748 A called, which discloses a centrifuge-type washing device. The technological background of spraying devices is also the US 1 714 232 A cited.

From the state of the art, methods are also known by the term "replacement wash", in which a washing liquid is conducted into the interior of the drum with recirculation lines extending radially outward in the interior of the drum, so that these enter into the interior of the drum radially and radially having an axial velocity component. The separated from the mother liquor solid phase is taken up by the washing solution and ejected as a washed washing suspension from the drum via nozzles as a nozzle phase from the drum ( Fig. 2 ).

This procedure has proven itself in principle, but there are mixing phenomena of the detergent phase with the surrounding solids-laden liquid or suspension, since the freshly "injected" washing liquid is lighter than the surrounding solids-laden liquid and therefore deflected radially inward.

The invention aims to reduce this problem.

The invention achieves this goal by the features of claims 1 and 6.

By the step of deflecting the washing liquid in the circumferential direction and the associated imparting a velocity component in the circumferential direction several advantageous effects are achieved, which reduce the problem described above.

Thus, the radial exchange of fresh wash solution and suspension is given increased resistance. Due to the additional peripheral speed, the centrifugal force is increased to the washing liquid. The specific heavier liquid can no longer completely or partially displace the washing liquid inwards.

Due to the diversion of the washing liquid flow in the circumferential direction u.U. Fillers and the like account for the inner wall of the drum, which has a constructive simplification of the centrifuge result and at the same time increases the usable drum volume.

Sedimentation of solids between the solids discharge nozzles are purged towards these nozzles.

It is even conceivable that some of the required solids discharge nozzles can be dispensed with, which reduces the machine costs and the risk of clogging.

The g-field is amplified by the additional peripheral speed.

Preferably, the outlet openings of the supply pipes are located in the circumferential direction between the Feststoffaustragsöffnungen to achieve a particularly good effect of the type described above. Alternatively, however, they can also lie radially in the extension of the outlet openings.

Advantageous embodiments of the invention are the subject of the dependent claims.

• Fig. 1 einen Schnitt durch einen Abschnitt einer erfindungsgemäßen Zentrifugentrommel senkrecht zur Drehachse;
• Fig. 2 eine zu Fig. 1 analoge Ansicht einer bekannten Zentrifugentrommel;
• Fig. 3 eine perspektivische Ansicht eines Abschnitts einer nach Art der Fig. 1 aufgebauten Zentrifugentrommel;
• Fig. 4 eine teilgeschnittene Ansicht eines Zulaufrohres; und
• Fig. 5 eine Diagramm, welches einen Produktverlust in % über einer Waschmenge in m³/h veranschaulicht.

Hereinafter, the invention will be described in more detail with reference to the accompanying drawings. Show it:

• Fig. 1 a section through a portion of a centrifuge drum according to the invention perpendicular to the axis of rotation;
• Fig. 2 one too Fig. 1 analogous view of a known centrifuge drum;
• Fig. 3 a perspective view of a portion of a type of Fig. 1 constructed centrifuge drum;
• Fig. 4 a partially sectioned view of a supply pipe; and
• Fig. 5 a diagram illustrating a product loss in% over a washing in m ³ / h.

Fig. 2 shows a section through a lower part 1 designed as a nozzle drum for continuous operation Separatortrommel 2 with a vertical axis of rotation.

In order to derive a solid phase, the separator drum 2 has solids discharge nozzles 3 in the region of its largest diameter.

The nozzle drum is rotatable by means of a drive, not shown here and has next to the in Fig. 2 components shown an inlet for a suspension to be processed, preferably a plate package of separating plates and one or more devices for the derivation of at least one liquid phase. Such devices are familiar to the skilled worker and require no further explanation here.

In addition to the feed for the suspension to be processed, the separator drum has an arrangement 4 for adding washing liquid into the interior of the drum (see also for a better understanding Fig. 3 ).

This arrangement has an inlet for washing liquid (not visible here), which may be formed, for example, concentrically to the inlet (pipe) for the suspension to be processed.

The inlet for washing liquid opens into a distributor 5 (see also Fig. 3 ), which has a plurality of circumferentially distributed outlet openings which open into radially in the drum outwardly extending supply pipes 6 for distribution and supply of the washing liquid into the drum interior.

The distribution pipes 6 extend in the prior art in the drum radially outward until just before the Feststoffaustragsdüsen 3 in the drum wall 8. Between adjacent Feststoffaustragsdüsen 4 wall reinforcements in the form of packing 9 are arranged circumferentially distributed here, in the interior of the separator drum. 2 protrude and which direct out of the inlet pipes 1 washing liquid in the direction of the solids discharge nozzles 3.

The supply pipes 6 for the washing liquid serve to guide the washing liquid, usually a specifically lighter washing acid, into the interior of the drum in the region shortly before the solids discharge nozzles 3.

As already explained in the introduction, in addition to the expected deflection of the jet of the washing liquid, it may also lead to an undesirably strong mixing with the suspension contained in the separator drum 2, since the freshly added washing liquid is lighter than the surrounding, solids-laden liquid or the suspension, so that the washing liquid is deflected inwards. This results in a transfer of the washing liquid in the upper reaches, whereby the effectiveness of the washing is impaired.

To counteract this effect, it is proposed as in Fig. 1 and 3 to recognize, to direct the washing liquid into the drum interior so that it has a speed component in the circumferential direction U - in the circumferential direction of rotation - when exiting the inlet pipe.

For this purpose, it is expedient to provide the inlet pipes 6, which extend radially outward in the interior of the drum, in their radially outer region with an arcuate deflection section 7 which serves to redirect the washing liquid from the radial direction in the circumferential direction U (in the direction of rotation).

This deflection section 7 is after Fig.1 formed as a 90 ° -Rohrbogen, wherein the outlet opening of the pipe bend is directed in the circumferential direction of rotation U, so that the washing liquid leaves the deflection device in the direction of rotation U.

As Fig. 4 shows, an outlet nozzle 10 may be arranged at the end of each supply pipe 6.

The deflection angle α in the circumferential direction U from the radial direction R is preferably between 45 ° and 120 ° (see also Fig. 4 ).

Different than after Fig. 2 the Separatortrommel 2 on its inner wall preferably no more filling, so that the inner circumference is circular or cylindrical.

In the washing process, first washing liquid, preferably a specific lighter scrubbing acid, is passed through the inlet pipes 6 in the edge region of the interior of the separator drum 2, where it exits in the circumferential direction U from the feed pipes 6 into the drum interior.

Fig. 5 shows a graph of product loss in the nozzle phase in% over the wash in m ³ / h.

The experiments were carried out in the separator DC 130 of the applicant. In this case, a highly concentrated salt solution was added to the product feed as a tracer and then the salt concentration in the upper run, or the gripper phase and lower run, or the nozzle phase determined. Thus, a complete mass balance could be carried out in the separator.

In this case, the previously known arrangement for the addition of washing liquid (according to Fig.1 ) I and the arrangement II according to the invention, wherein the measured values for the known arrangement are represented by diamonds I.1-I.3 and the measured values for the arrangement according to the invention are shown by squares II1-II6.

In the previously known arrangement for the addition of washing liquid (according to Fig.1 ), the ratio in which the respective amounts were divided into upper and lower run, was strongly influenced by the densities of the washing liquid and the product flow. These are dependent on the salt content. If the washing liquid is heavier than the product liquid, then there is no significant mixing in the known arrangement.

When looking at the measured values of the arrangement according to the invention, it was found that the loss of liquid product, which can occur through the mixing of the heavier liquid product phase with the lighter washing liquid, is reduced as the amount of washing increases.

Although radial mixing could not be completely ruled out even with the addition of the lighter washing liquid in the circumferential direction, less product is lost in discharging the solid phase with the washing liquid.

LIST OF REFERENCE NUMBERS

lower part 1 separator 2 solid discharge 3 arrangement 4 distributor 5 supply pipes 6 deflecting 7 drum wall 8th packing 9 exhaust nozzle 10 circumferential direction U

Claims (6)

1. Nozzle separator having a vertical rotational axis A, having a rotatable drum (2) for processing an inflowing suspension, the drum (2) being provided with an assembly (4) for supplying washing liquid into the drum interior, which has multiple supply pipes (6),wherein the multiple supply pipes (6) are implemented and arranged in the drum (2) such that the washing liquid exits from them with a velocity component in the peripheral direction, characterized in that the drum (2) is provided with a plurality of peripherally-distributed solid discharge nozzles (3), the number of supply pipes (6) corresponding to the number of solid discharge openings (3), and that the supply pipes (6) for washing liquid each have a section extending radially in the drum and a curved section (7) adjoining thereon to the outside for deflecting the washing liquid in the peripheral rotational direction.
2. Nozzle separator according to Claim 1, characterized in that the supply pipes (6) each have an outlet opening, which is provided with an outlet nozzle (10).
3. Nozzle separator according to one of the preceding claims, characterized in that no packing is formed on the drum inner wall between solid discharge nozzles (3) which are adjacent in the peripheral direction.
4. Nozzle separator according to one of the preceding claims, characterized in that the outlet openings of the supply pipes (6) are located in the peripheral direction between the solid discharge openings (3).
5. Nozzle separator according to one of the preceding claims, characterized in that the outlet openings of the supply pipes (6) are each located in the peripheral direction centrally between solid discharge openings (3) adjacent to one another.
6. A method for diverting a solid phase from a nozzle separator, which is implemented according to one of the preceding claims, characterized in that the washing liquid is conducted with a velocity component in the peripheral direction (U) into the drum interior.

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