FR2584949A1 - HYDROCYCLONE, IN PARTICULAR FOR PURIFYING PAPER SUSPENSIONS - Google Patents

Abstract

THE INVENTION RELATES TO A HYDROCYCLONE FOR SOLID LIQUID SEPARATION. IN THE HYDROCYCLONE OF THE INVENTION, THE FLOWWAYS FOR THREE FRACTIONS ARE LOCATED NEAR THE EXIT END IN THE NARROW PART OF THE HYDROCYCLONE CONE WHICH IS CONSTRUCTED AS A TRUNK CONE-SHAPED BUILDING EXCEPT IN THE ENTRANCE ZONE. IN THE AREA OF THE PART OF THE TRUNCATED CONE ARE FLOW CHAMBERS, AND A CENTRAL 1 FLOW PIPE FOR LIGHT WASTE PASSING THROUGH THESE CHAMBERS. A FLOW PIPE 2 ON THE EXTERIOR, COAXIAL WITH THIS FIRST FLOW PIPE CROSSES THE FIRST FLOW CHAMBER AND ENTERS THE SECOND CHAMBER 4 IN WHICH AN AVERAGE FRACTION IS RECOVERED. THE HEAVY FRACTION IS RECOVERED IN THE FIRST CHAMBER 3. THE OUTSIDE 2 CONCENTRIC FLOW PIPE EXTENDS A SMALL PART INTO THE CONE-SHAPED CHAMBER OF THE DEPASTILER, BUT NORMALLY MUCH LESS THAN FOR THE CENTRAL APPLICATION 1. THE SEPARATION OF FIBROUS STATIONERY MATERIALS IN PARTICULAR.

Description

The subject of the invention is a

  a drocyclone intended in particular for fine purification with a thicker one-way flow at the inlet and more fluid at the outlet, the hydrocyclone narrowing anyway in the form of a truncated cone normally in the region near the exit end , and a flow pipe provided for the fraction enriched with light impurities penetrating the center

  of the flow opening of the cone-shaped portion.

A hydrocyclone of the aforementioned type

  has been described in European Patent Application 0058484.

  According to this patent, it is a hydrocyclone with a nonretrogressive (one-way) stream. With such a device is found in an exemplary embodiment (fig.3) the possibility of the flow of three separate fractions. In this case, two flow chambers are provided, one behind the other, one for the heavy fraction and one for a

  medium fraction, which are connected with a

  center for light waste going into the cone-shaped part of the hydrocyclone. In this case, the average fraction is separated so that from the furthest chamber provided for this fraction, an extension of the truncated cone sinks into the chamber for the heavy fraction and forms a flow chamber. Ring shape in front of the drain pipe. However, we have not yet managed to make this hydrocyclone constructible; this wants

  to say that it works extremely badly.

  In addition, a hydrocyclone has been disclosed by DE-OS No. 461,195, which serves to clean the cellulose suspensions. In this case, it is preferable to obtain an extraction on the one hand of the nibs of the cellulose and on the other hand impurities in balls or in small balls. With such a device it has not been realized that by means of a certain size of the coaxial pipes as well as a choice of the relative distances from one with respect to the other, the separation can be obtained. complete with light impurities on the one hand and heavy impurities (in the form of small balls or balls) on the other hand, so that the main mass of the fibers is in the drain pipe in the center. It is for this reason that this cyclone is not provided for the cleaning of old papers, which, as is well known, contain a large part of so-called light impurities.

The object of the invention

  to make available a hydrocyclone with which

  a perfect separation of the three fractions is possible

  ble, in order to obtain a defined heavy fraction without impure-

  light, and a lightly enriched fraction of light impurities, also in the form of thin chips. This problem is solved with a hydrocyclone of the aforementioned type characterized in addition and generally in that it comprises a second outward flow pipe for a medium fraction, said second pipe lying coaxially with respect to the first flow pipe and penetrating the cone-shaped portion as far as the first flow pipe. Preferably the coaxial pipe occupies at least% and at most 85% of the diameter of the outlet opening of the

  construction of the hydrocyclone (truncated cone). Preferably the former

  exit end of the second flow pipe enters a separate recovery chamber, through which the first flow pipe is directed while the first flow pipe passes through a first recovery chamber for the fraction (heavy fraction )

  enriched with heavy impurities or heavy particles

  perched on the edge of the hydrocyclone frame at the end of

  outlet of the first drain pipe.

  Advantageously, while the outer diameter of the coaxial outer pipe is between 75% and 85% of the diameter of the outlet end, the outer diameter of the inner pipe is at most 40% of the latter. Preferably, the coaxial outer pipe penetrates at least 4 mm and the internal drain pipe at least 20 mm to 60 mm into the cone-shaped portion

25849.9

  truncated. Preferably the inner flow pipe protrudes from the coaxial outer pipe by at least 15 mm in the truncated cone-shaped portion. Preferably, the angle of the cone is between 2 and 5, that is to say that the opening angle of the cone is between 4 and 10; of

  preferably this opening angle is between 50 and 8.

  The present invention will be better understood and details thereof will be apparent to the

  description that will be made of a particular form of

  realization, in relation to the figures of the attached single plate in which:

- fig.1 is a sectional section

  longitudinal section of a cyclone of the invention, and - fig.2 is a magnified detail

from the previous figure.

1 In Figures 1 and 2, the hydrocyclic

  clone has a conical body with an opening angle <between 4 and 10, preferably between 5 and 8, as was usual up to now. The hydrocyclone may also have a cylinder shape in the inlet zone at the top of the large diameter hydrocyclone. At the outlet end of the hydrocyclone are two coaxial flow pipes 1 and 2; in this case the central pipe 1 is provided for the light fraction and the outer coaxial pipe for a medium fraction. The pipe outside 2 is in this case guided in the conical part of the hydrocyclone through an extraction chamber 3 for a heavy fraction. The distance with which this pipe enters the conical part is indicated by fi in FIG. This distance can also be practically zero and is normally less important than the distance f3, with which the central pipe enters the conical part. The distance f3 is preferably 20 to 60 mm and the distance f1 is at least about 4 mm. In this case, the difference in immersion depths, whose distance f2 = f3 - fl, should preferably be at least

about 15 to 20 mm.

258C- 9

In this case, it is not important

  while in fact at the very bottom of the conical portion, the conical wall no longer exists since at this location the upper wall 10 of the flow chambers 3 and 4 has a cylindrical inner passage opening. Since this represents a very small distance of about 4 to 5 mm, this small inaccuracy is not important. It would naturally be possible to construct the hydrocyclone in such a way that the conical portion on the wall 10 is not laid, but that the recess, that is to say the passage opening of the wall 10, is chosen. a little bigger and that we do

  penetrate the conical part into the wall 10.

It is shown to be very

  select the outer diameter D2 of the concentric outer pipe 2 of at least 70% and not more than 85% of the diameter

  D3 of the passage opening of the wall 10 or the opening

  flow of the conical part. In addition, it is also advantageous that the diameter D1 of the central inner pipe is at most about 40% of the outside diameter of the outer pipe 2, if it is at least 75 and at most 85% of the diameter D3 of the opening of the flow

16 of the conical part.

As indicated, provision is made

  a heavy fraction at the outer edge of the cone-shaped portion. This arrives in the chamber 3 and is evacuated through the extension pipe 5. The outer pipe 2 brings an average fraction into the lower chamber 4; it is evacuated with the aid of the extension pipe for the flow 6. In this case, the extension pipes for the flow 5 and 6 are preferably connected in such a way

tangential to the rooms.

The mode of action of the hydrocyclic

  The clone of the invention is very good insofar as a very large quantity of light impurities, especially glues, accumulates in the central flow pipe, and a very good separation of heavy impurities on the edge of the cone. is made in the direction of the chamber 3 in which virtually no light impurity can occur. In the lower chamber 4 there are still almost more heavy impurities, but in part light impurities which however can be easily separated in subsequent levels of this type of hydrocyclone. Although a particular and preferred embodiment of the invention has been described and / or represented, it should be understood that the scope of the invention is not limited to this form, but extends to any device with the characteristics

general rules set out above.

R E V E N D I C AT IONS

  1.- Hydrocyclone intended in particular for fine purification with a thicker one-way flow at the inlet and more fluid at the outlet, the hydrocyclone narrowing anyway in the form of a truncated cone normally in the part adjacent to the outlet end, and a flow pipe provided for the fraction enriched with light impurities in the center of the flow opening of the cone-shaped portion, characterized

by a second pipe of

  outwardly (2) for a medium fraction, said second pipe lying coaxially with the first flow pipe (1) and penetrating the cone-shaped portion as far as the first flow pipe (1); 2. Hydrocyclone according to claim 1, characterized in that the coaxial pipe occupies at least 70% and at most 85% of the diameter of the outlet opening (16) of the frame of the hydrocyclone (truncated cone);

  Hydrocyclone according to claim 1

  and 2, characterized in that the outlet end (16) of the second flow pipe (2) enters a separate collection chamber (4) through which the first flow pipe (2) is directed. ), and in that the first flow pipe (1) passes through a first recovery chamber (2) for the fraction (heavy fraction) enriched with heavy impurities or heavy particles

  recovered at the edge of the frame of the hydrocyclone at the

  exit of the first flow pipe (1); S894 '

  4. Hlydrocyclone according to any one of claims i

  to 3, characterized in that, while the outer diameter of the coaxial outer pipe (2) is between 75% and 85% of the diameter of the outlet end, the outer diameter of the inner pipe (1) is at maximum of 40% of the latter;

  5. Hydrocyclone according to any one of claims 1

at 4, characterized

in that the outer pipe

  the coaxial pipe (2) penetrates at least 4 mm and the internal drain pipe (1) at least 20 mm to 60 mm into the truncated cone-shaped portion; 6. Hydrocyclone according to claim 5, characterized by:

by the fact that the water pipe

  the inner (1) exceeds the coaxial outer pipe (2) by at least 15 mm in the truncated cone-shaped portion;

  7. Ilydrocyclone according to any one of claims 1

  at 6, characterized in that the angle of the cone is between 2 and 5, that is to say that the opening angle of the cone is between 4 and 10; Hydrocyclone according to claim 7, characterized by:

by the fact that the opening angle

  The cone is between 5 and 8.