FR2509337A1 - FLOATING DEVICE FOR THE TREATMENT OF OLD PAPERS - Google Patents

Abstract

THE INVENTION RELATES TO A FLOTATION DEVICE FOR THE TREATMENT OF OLD PAPER INCLUDING A FLOTATION CONTAINER 1 HAVING THE SHAPE OF A VERTICAL CYLINDER INCLUDING ON ITS PERIOD INJECTION MEANS FOR ADMITTING THE SUSPENSION MIXED WITH THE FOLLOWING AIR. SUBSTANTIALLY TANGENTIAL AND HORIZONTAL DIRECTION. THE SUSPENSION OF OLD PAPER MIXED WITH AIR IS ALLOWED IN THE FLOTATION CONTAINER BY MEANS OF A DIFFUSER 5 TO 9 SINGLE AGENCY NEAR THE BOTTOM OF THE SAID CONTAINER AND THE DRAIN PIPE 3 OF THE DEPLETED SUSPENSION IS NEXT TO THE DIFFUSER CONNECTION 2 OPENING, THEREFORE LOCATED NEAR THE BOTTOM OF THE CONTAINER.

Description

FLOATING DEVICE FOR TREATMENT

OLD PAPERS

  The invention relates to a flotation device for the treatment of waste paper, of the type in which the flotation container has substantially the shape of a vertical cylinder in which the suspension, mixed

  to air, is admitted according to a sub-

  stantially tangential and horizontal by means

  injection lines arranged around the cylinder.

  Such a device is known by the de-

  German patent application DE-AS 29 14 393 The device

  written in the German application cited is one of many

  its attempts to improve the degree of flotation efficiency by means of injectors feeding the flotation container of substantially cylindrical shape, with

  the suspension mixed with air In this device, the

  evacuation of the suspension also takes place near im-

  bottom of the container Regarding the suspension

  untreated, admission takes place first

  times by means of several injectors distributed over the

  container around halfway up, then a second time at a lower level o other injectors supply the already treated suspension container This arrangement with the suspension supply on two levels by means of a plurality of injectors makes the known device really complicated and of an exacting use Surveillance must also be the subject of an important attention, under

  worth introducing a relatively large factor of insecurity.

  The objective of the present invention is to offer a flotation device operating flawlessly despite a simple construction, that is to say allowing to achieve energy savings and to separate

  waste with a good degree of efficiency thanks to the existence

  this many air bubbles widely distributed in the

  suspension inside the container.

  Ld essential edracierism of information

  vention lies in the fact that the admission of the suspension takes place by a single intake pipe connected to the

  around the cylinder and comprising a widening of diff

  merger and, upstream of it, means of injecting

  tion of the flotation air. According to an advantageous embodiment, the widening of diffusion forms part of the nozzle of a

  water jet pump type injector.

  According to another form of partial execution

  particularly suitable, the injector forms a free-to-play

  ambient air piracy, created by the circulation of 1-a suspension through said injector inside which 'said suspension coming out of an opening, iu at least one supply line is directly directed on the opening horizontal intake of a mixing line Thanks to the arrangement of a free jet injector, a particularly good ventilation of the suspension is obtained In addition, the arrangement of the intake opening of the pipe

  mixing at a height above the level of li-

  in the flotation container, which is

  b Island in a simple way, makes it possible to prevent the suspension from overflowing. It may be advantageous for the injector to comprise several parallel intake pipes, which improves

  further ventilation of the suspension 'By determining

  the current inside the flotation vessel, it is also possible to simply remove the foam

  by means of a central overflow tube.

  The invention will now be explained.

  tée in the light of the drawing representing various forms

of execution.

  In this drawing are mounted res: -figures la and lb: an arrangement according to the invention with a diffuser, the flotation container being only symbolized by broken lines,

Figure 2: an arrangement according to the

  vention with an injector of the water jet pump type.

  Variants dec; figures la and lb pro

  pose a particularly simple diffuser 10 for the diff-

  air melting This is blown into the suspension by a pipe 14 opening out before the diffuser In the case of FIG. 1b, where the pipes 4 and 14 are sensi

  horizontal, valves must be provided to

  avoid backflow of the suspension when the installation

  tion is at rest. The injector variant of Figure 2 works quite similarly? The suspension is directed from line 4 to the mixing line 6 through the lines

  5 These and the mixing line 6 consist of

  kill the injector In this case, several delivery lines

  are connected to the mixing line but it is however possible to directly connect line 4 to the mixing line 6 The air intake takes place

  at the level of the inlet funnel 7 which is provided with the

  mixing line 6 The inlet opening 9 of the enton-

  black 7 and the drain openings-S of the pipes

  your supply leads 5 open substantially horizontally

  the and the suspension is admitted into the mixing line 6 in an essentially vertical direction Instead of the injector shown, it is also possible to provide a closed injector operating according to the principle

  of Venturi, air being introduced into the supply line

  mission at the level of a constriction The example of the embodiment shown has the advantage, however,

  to require only a very simple construction and

  Be sure to provide good air intake into the suspension The intake opening 9 of the funnel 7 is located high enough above the liquid level

  20 in the flotation container 1 to avoid backflow

  lement of the suspension when the installation is at rest.

  No monitoring is required here

  leads to greater simplicity of installation.

  The flotation container consists essentially of a vertical cylinder on the axis of which is disposed a central interior cylinder. An annular space is thus formed between the internal wall of the container.

  flotation and the outer wall of the central cylinder Ad-

  mission of the suspension takes place after the injector by means of an inlet pipe 6 ′ of rectangular section, the longest sides of which are horizontal The suspension is thus directed in a jet widely spread out from the opening connection 2 of the intake pipe 6 '

  essentially in a tangential direction but-

  however over the entire width of the annular space to

  inside the flotation container-l The suspension,

  air-changed, is lighter than the suspension already

  degassed which is near the evacuation pipe -

  tion 3 located in the bottom of the flotation container 1 next to the intake pipe 6 ', which drives it upwards in a rotating current The waste particles

  cling to the gas bubbles which cause them to over-

  face of the suspension The foam thus formed is then evacuated

  cured by the opening 22 for scavenging the foam, that is to say

  say in practice overflows inside the central hanger This process can be helped by blowing air

  on the surface of the suspension in order to repel the foam.

  This only involves low energy expenditure.

  Furthermore, it is possible to use a tube 12 and an air blowing funnel directed at

  against the current and sucking up the foam.

  Avoid a short circuit between the

  sion and the evacuation of the suspension by erecting a partition wall 16 whose height is roughly between one third and half the height of liquid in the

flotation container '-

  Of course, the admission of the suspension is in tangential essence only if it is desired. It is also possible to deviate from the horizontal direction within narrow limits If necessary, if one% had to increase the degree purity of the suspension, we can have several flotation vessels in series We thus get a gain

of important place.

  I 1 is advantageous that the height of the

  suspension inside the flotation container either-

  between 70 and 120 cm, preferably between 75 and 100 cm.

  We use a flotation container 300 cm in diameter

  for a central cylinder 100 cm in diameter, which

  gives the annular space a width of 100 cm. The device according to the invention differs

  again from the device described in the German patent application

  mand DE-OS 29 04 619 in that the height of the suspension should only be 40 cm, that the admission is done only on the outside and in a non-horizontal direction, and finally that the evacuation of the suspension is by

  central flow With regard to the evacuation of

  cume, it can only take place in practice by aspiration.

Claims (8)

  1 / Flotation device for the treatment of waste paper, comprising a flotation container having essentially the shape of a vertical cylinder in which the suspension, mixed with air, is admitted according to a substantially tangential current and   horizontal by injection means arranged on the   cylinder turn, characterized in that the intake of the upper suspension by means of a single intake pipe (6, 6 ') connected to the periphery of the cylinder and comprising   a widening of diffusion (6, 10) and, upstream of it   ci, means for injecting Vlair flotation.   2 / Device according to claim 1, characterized in that the diffusion widening (10) is part of the nozzle of an injector (5 to 9) of the type water jet pump -   3 / Device according to claim 2, characterized in that the injector (5 to 9) is adapted to form a free jet of suction of the ambient air, created by the circulation of the suspension in said injector, the interior of which said suspension emerging from an opening (8) of at least one supply pipe (4, 5) is directly directed onto the horizontal intake opening (9) of a mixing line (6).   4 / Device according to the claims   1, 2 and 3, characterized in that the inlet opening (9) of the mixing line (6) is arranged above the level of the liquid inside the flotation container (1).   / Device according to one of the claims   cations 1 to 4, characterized in that a plura-   lity of parallel pipes (5) for supplying the suspension.   6 / Device according to one of the res   dications 3 or 5, characterized in that the metering line   diaper (6) _ has a widening (7) in the form of a funnel   black at its end directed towards the supply lines   (5) and that said supply lines plunge into the   widening (7) in the form of a funnel.   7 / Device according to one of the res-   dications 1 to 6, characterized in that, coaxially inside the flotation container (1), is arranged a central cylinder (15) exceeding the level of liquid contained   naked in said flotation container (1).   8 / Device according to the claim   7, characterized in that the central cylinder (15) is adapted   tee to constitute a discharge opening (22) of the   cume, in the form of an overflow communicating the surface of the suspension with the interior of said cylinder central (15).   9 / Device according to one of the res   dications 1 to 8, characterized in that a partition wall   tion (16) is erected from the bottom of the flow container-   tation (1) between the internal wall of said container and the   outer wall of the central cylinder (15) over a height   taken between a third and a half the height of liquid   to separate the opening (2) from the intake pipe   sion (6 ') and the discharge pipe (3) of the suspension.   / Device according to claim 8, characterized in that the foam discharge opening   (22) is located at a height such that the level of the   board in the flotation container (1) is included   between 0.7 and 1.2 m, preferably between 0.75 and 1 m.