FR2666026A1 - Phase separator for laden liquids and purification plant comprising such a separator - Google Patents

Abstract

Phase separator for laden liquids consists of a separating vessel which comprises an outer cylindrical wall 7, a conical bottom 8 open in the middle to allow the loads to be discharged by gravity, an annular channel 11 arranged in the vessel by means of a jacket 10 open in its lower part, at least one horizontal tangential entry into the annular channel 11 and a syphon 12 for removing separated water. The plant comprising this separator consists of a screen grid separator 1 which feeds the said separator and of a hydrocyclone 14 which, through the intermediacy of a receiver trough 19 housed in the separator 6, can function as a closed circuit by recycling purified water by means of a set of level sensors 23, 24, 25. The plant is more particularly suitable for the treatment of liquid-solid mixtures of different density and for removing sludge from sewage or industrial effluence such as water from washing mushrooms, carrots or beets.

Description

 The present invention relates to a phase separator for charged liquids and it also relates to the purification installation comprising such a separator.

 In certain industries, it is frequent to encounter problems linked to pollution, which oblige to adopt solutions of treatment of liquids and in particular of water. The installation is more particularly suited to the treatment of liquid-solid mixtures of different density, settling of waste water or industrial water such as water for washing mushrooms, carrots or beets.

The existing equipment is sometimes too bulky or its effectiveness is random due to the products to be treated.

Thus, for example, the treatment of the water for washing the mushrooms before cooking cannot be carried out satisfactorily with conventional equipment because of the presence of sand, mud and the like.

 The present invention provides equipment more particularly suited to this type of application. This equipment has the advantage of being 5 to 10 times less bulky than a conventional static device.

 This material also has the advantage of being particularly suitable for easy maintenance. It also has the advantage of being able to operate intermittently which allows substantial energy savings.

 The invention relates firstly to a phase separator for charged liquids. This separator consists of a settling tank which comprises - a cylindrical external wall - a conical bottom open in the center to allow the evacuation by gravity of the charges - an annular channel arranged in the tank by means of a double cylindrical internal wall open at least at its lower part - at least one horizontal tangential inlet, in the annular channel, for the introduction of the charged liquid - a siphon for discharging the settled water.

 According to a preferred arrangement of the invention, the internal double wall is made up of removable slab panels, in the form of a cylindrical sector these slabs are partially superimposed at their ends, assembled on suitable supports which are integral with the conical bottom, which supports are distributed on a circle, separated from each other so as to provide a determined passage section, under the sheet panels, for the charges and the carrier liquid.

 Still according to the invention, each panel of the double partition has a square fold, located inside the tank, which fold extends over the height of the panel with the exception of the lower part in contact with the support, so as to allow support of said fold on said support and to maintain a precise spacing between the bottom of the tank and the lower edge of the panels; these folds also give good rigidity to the assembly.

 According to another arrangement of the invention, the tangential entry of the liquid loaded into the tank takes place by means of a nozzle disposed at a certain height from the bottom, which is a function of the number of nozzles, of the viscosity of the carrier fluid. and device flow.

 The invention also relates to an installation for purifying charged liquid, of the type comprising a screen and at least one hydrocyclone; this installation also comprising a phase separator which is supplied by the screen and which is connected to the hydrocyclone, by means of a pump placed between the outlet of the tank of said separator and the inlet of the hydrocyclone.

 Still according to the invention, the installation comprises a tank for receiving the purified liquid, supplied by the overflow of the hydrocyclone, which tank comprises an overflow for discharging the purified liquid and, at its lower part, a connection valve. of said tank with the separation tank.

 According to another arrangement of the invention, the installation comprises means for controlling the valve, which means consist of level sensors which are arranged in the separation tank - a sensor located on the upper level which allows the starting of the installation, connection valve closed - a sensor located at the lower level, which controls the opening of the connection valve so as to operate the installation in recycling mode - an intermediate sensor which controls the closing of the connection valve when the liquid level rises in the tank.

 Still according to the invention, and according to a preferential arrangement, the installation comprises, associated with the sensor of the lower level, a timer which limits the operating time of the recycling, which timer is stopped and reset to zero during 1 t activation of the sensor. arranged at the intermediate level.

 According to another preferred arrangement of the invention, the installation comprises a tank for receiving the purified liquid, placed in the separation tank.

 According to another arrangement of the invention, the tank comprises, at its lower part, a deflector which widens the suction opening of the charges at the lower part of the cone.

The invention will be further illustrated, without being in any way limited, by the following description of an embodiment, given by way of indication, and represented in the appended drawings, in which - FIG. 1 is a schematic and functional view of a installation according to the invention - Figure 2 is a sectional view of the phase separator according to the invention; - Figure 3 is an enlarged view of the bottom of the separator shown in Figure 2 - Figure 4 is a partial view of the separator tank, showing the positioning of the panels forming double partitions - Figure 5 is a partial radial sectional view of the separator tank - Figure 6 is a top view of the separator showing the arrangement of the nozzles which are used to inject the charged liquid into the separator
The installation, represented diagrammatically in FIG. 1, includes a screen 1 which allows a first phase separation by setting aside the waste with large particle sizes. This screen is supplied at its upper part by a pipe 2; the screen 1 essentially comprises an inclined screen 3. Waste with large particle sizes is discharged according to arrow 4, at the bottom of the sieve 3. The remaining charged liquid is collected under the sieve 3 and it is evacuated via a pipe 5 to the phase separator.

 The phase separator 6 essentially consists of a tank comprising an external cylindrical wall 7 surmounting a conical bottom 8. This conical bottom 8 comprises, at its lower part, a charge discharge orifice by means of a pipe 9 whose it will be discussed further.

 This separator 6 comprises a double internal partition 10, of cylindrical shape, doubling the external wall 7.

The space between the walls 7 and 10 forms an annular channel 11 into which the charged liquid from the screen 1 is injected, via line 5.

 The separator also includes a siphon 12 which allows the evacuation by the pipe 13, of the decanted liquid.

 The purification of the liquid is improved by the addition of a hydrocyclone 14 supplied by a pump 15 which recovers, by means of the pipe 9, the charges contained in the conical part 8 of the separator 6. These charges are introduced into the hydrocyclone 14, at its upper part, via a pipe 16. Hydrocyclone 14 separates the charges from the liquid. The charges are discharged through a line 17 connected to the head of the hydrocyclone, while the purified liquid is ejected through a line 18 connected to the overflow, that is to say disposed at the top of the hydrocyclone 14.

 Note, FIG. 1, that the pipe 18 reintroduces the purified liquid into the separator 6. The separator 6 comprises a tank 19 for receiving the purified liquid coming from the hydrocyclone 14. This tank 19 is provided, at its lower part, with a 'A valve 20 which allows its communication with the separator 6. This tank 19 also includes a siphon 21 which allows the discharge to the outside by means of a pipe 22, of the purified liquid.

 In the example of FIG. 1, the tank 19 is placed in the tank of the separator 6.

 This type of installation, that is to say comprising a screen 1, a phase separator 6 and a hydrocyclone 14 allows effective separation of the solid and liquid phases. Above all, it makes it possible to improve the functioning of the hydrocyclone and in particular to mask the transient regimes which constitute a loss of efficiency of the hydrocyclones and of the installation in general.

 In case of insufficient liquid flow, the installation and in particular the hydrocyclone 14 can continue to operate thanks to a closed circuit which allows recycling of the purified liquid. Level sensors are arranged on the tank of the phase separator 6. A sensor 23 is placed on the upper level of the tank of the separator 6. This sensor authorizes the start-up of the installation when the tank of the separator 6 contains sufficient liquid and that the valve 20 is closed. This sensor 23 is situated at a level substantially lower than the priming level of the siphon 12 of the tank 6.

 A second sensor 24, placed at the lower level of the tank 6, substantially above the level of the valve 20 of the tank 19, controls the opening of this valve 20 to allow the recycling of the purified water coming from the hydrocyclone 14. This recycling avoids malfunctions of the hydrocyclone 14 by allowing it to operate continuously. This operation of the hydrocyclone 14 in the recycling phase is limited by means of a time delay which controls the stopping of the installation and in particular of the pump 15 when the operating time in recycling exceeds a predetermined time, of around 30 minutes for example.

 A third sensor 25, disposed between the sensors 23 and 24, and arranged in particular below the priming level of the siphon 21 of the tank 19, controls the closing of the valve 20 and consequently the stopping of the recycling of the purified liquid. This sensor 25 also switches off the recycling control timer and resets it.

 FIG. 2 shows in more detail the phase separator 6 which is used in the composition of the purification installation shown in FIG. 1.

 This phase separator 6 comprises two separation modes: a conventional separation by decantation in a tank, by simple gravity of the particles in a mass of inert liquid, and a separation by vortex, around the inert mass.

 We find, in Figure 2, the same references as those used in Figure 1. The separator 6 comprises an external cylindrical wall 7 mounted on a conical bottom 8, which bottom 8 rests on feet 26. This bottom 8 has a suitable slope to allow a gravity flow, of the sand pile type, of the charges deposited by the liquid.

 This bottom 8 comprises, at its lower part, an orifice 27 for discharging the charges, connected by line 9, to the pump 15 supplying the hydrocyclone 14. It is also noted, in FIG. 2, a valve 28 serving to emptying the separator 6 if necessary.

 FIG. 3 shows an enlarged view of the bottom of the cone 8. It is noted, above the discharge orifice 27, a deflector 29 in the form of a cap, secured to the bottom 8 by means of several bolts 30. This deflector 29 makes it possible to avoid the central suction of the charges in the cone 8; it broadens the suction of the charges by increasing the suction surface. The deflector however has a small central orifice 31, above the orifice 27, so that it can be drained.

 Note, Figure 2, the double wall 10 arranged inside the separator 6. This double wall 10 is also cylindrical. It rests on the bottom 8 by means of supports 32 detailed below.

 The walls 7 and 10 define an annular channel 11 of small thickness, which extends practically over the entire height of the tank of the separator. This annular channel 11 receives the charged liquid by means of pipes 5 connected to the screen. Each pipe 5 introduces the charged liquid into the lower part of the annular channel 11, tangentially, as will be shown below, to swirl the charged liquid in this annular space 11 and to cause separation of the liquid phase maintained in the upper part of the channel, while the charges descend into the cone 8 of the tank passing through orifices 33 arranged in the lower part of the internal wall 10. These elements will be detailed a little later.

 Note also, Figure 2, the overflow 12 disposed in the separator tank 6 and the tank 19 for receiving the purified liquid. This tank 19 is arranged in the separator tank, secured to the bottom 8 by a support 34. This tank 19 contains a siphon 21, which siphon 21 communicates with the outside by passing inside the support 34.

 The tank 19 comprises at its lower part, a valve 20 supported by tie rods 35 and 36. This valve 20 places the interior of the tank 19 directly in communication with the interior of the tank of the separator 6.

 Note also, in FIG. 2, a portion of a tube 37, in which the three level sensors 23, 24 and 25 mentioned in FIG. 1 are housed.

 There is shown, in more detail, FIG. 4, a portion of the separator tank 6. We note the conical bottom 8 and the cylindrical outer wall 7, integral with said bottom 8. On this bottom 8 are welded right through, on a circle, supports 32 serving to hold the internal wall 10. This internal wall 10 is preferably made up of panels in the form of cylindrical sectors to allow in particular an easier disassembly and especially the cleaning of the tank. This wall 10 is formed for example of six sheet metal panels 101, 102, etc., supported at their lower parts by the supports 32 and, at their upper parts by a flange 37 provided for example with lugs 38 for fixing. note that each panel 101, 102, ..., has a fold 39 at right angles, which extends over almost the entire height of the corresponding panel, with the exception of the lower part. This fold 39 in fact rests on the supports 32 and thus makes it possible to maintain a certain distance between the lower edge 40 of the wall 10 and the bottom 8 so as to create the passage orifices 33 through which the charges and the liquid are discharged. which enter the annular channel 11. These folds 39 also cause greater rigidity to the panels 101, 102, etc.

 The section of the orifices 33 is determined as a function of the flow rate of charged liquid which enters the annular channel 11.

 There is shown, Figure 5, in more detail, the fixing of the panels 101, 102 forming the wall 10, on the lower supports 32 and the upper flange 37 which is integral with the outer wall 7. The panels overlap and are fixed to the by means of bolts 41 and 42 on the supports 32 and on the lugs 38 which are integral with the flange 37. It is noted that the heads of the bolts 41 include counterbores 44 to facilitate the mounting of the panels 101, 102.

 There is shown, Figure 6, in top view, the separator 6 so as to show the distribution of the nozzles 45 which ensure the tangential introduction into the annular channel 11, of the charged liquid. These nozzles 45 are regularly distributed and fixed on the cylindrical outer wall 7. They are supplied under pressure from the outlet pipe 5 of the screen 1, by means of a pump for example, not shown. The nozzles 45 are for example six in number, and they are arranged in a horizontal plane and at a height relative to the bottom of the annular channel which corresponds substantially to 1 / 5th of the height of said channel; this height essentially depends on the number of nozzles, the viscosity of the carrier fluid and the flow rate of the device.

 The reference signs inserted after the technical characteristics mentioned in the claims are intended only to facilitate the understanding of the latter and in no way limit their scope.

Claims (10)

- CLAIMS  1.- Phase separator for charged liquids characterized in that it consists of a settling tank comprising - an external cylindrical wall (7) - a conical bottom (8) open in the center to allow the evacuation by gravity of loads - an annular channel (11) arranged in the tank by means of a cylindrical internal double wall (10) open at least at its lower part - at least one horizontal tangential inlet, between the external (7) and internal (10) walls ), allowing the introduction of the loaded liquid into the tank - a siphon (12) for discharging the settled carrier liquid.  2.- phase separator for charged liquid, according to claim 1, characterized in that it comprises a double internal wall (10) consisting of sheet metal panels (101, 102, ...,) removable, in the form of sectors of cylinders, partially superimposed at their ends, assembled on supports (32) integral with the conical bottom (8), which supports (32) are distributed in a circle, separated from each other so as to provide a determined passage section for the charges and the carrier liquid.  3.- phase separator for charged liquid, according to claim 2, characterized in that it comprises on the panels (101, 102, ..), the double partition (10), a fold (39) at the bracket, located inside the tank, which fold (39) extends over the height of the corresponding panel, with the exception of its lower part which is in contact with the corresponding support (32) so as to allow the 'support of said fold (39) on said support and to maintain a precise spacing between the bottom (8) and the lower edge (40) of the panels.  4.- phase separator for charged liquid, according to claim 3, characterized in that it comprises a tangential inlet in the form of a nozzle (45), mounted on the outer wall (7) and disposed au- above the bottom (8).  5.- Installation for purifying charged liquids, of the type comprising a screen (1) and at least one hydrocyclone (14), characterized in that it comprises a phase separator according to any one of claims 1 to 4, which separator is supplied by the screen (I) and is connected to the hydrocyclone (14) by means of a pump (15) placed between the outlet of the tank of said separator and the inlet of said hydrocyclone.  6.- Installation for purifying charged liquids, according to claim 5, characterized in that it comprises a tank (19) for receiving the purified liquid, supplied by the overflow of the hydrocyclone (14), which tank (19 ) comprises an overflow (21) for discharging the purified liquid and, at its lower part, a valve (20) for connecting said tank with the separation tank.  7.- Installation for purifying charged liquids according to claim 6, characterized in that it comprises means for controlling the connection valve (20), consisting of level sensors arranged in the phase separation tank - a sensor (23) arranged on the upper level, which allows the installation to start, valve (20) closed - a sensor (24) arranged on the lower level, which controls the opening of the valve (20) so as to operate the hydrocyclone (14) in recycling - an intermediate sensor (25), which controls the closing of the valve (20) when the liquid level rises in the separator tank (6).  8.- Installation for purifying charged liquids, according to claim 7, characterized in that it comprises, associated with the sensor (24) of the lower level, a time delay which limits the operating time of the hydrocyclone in recycling, which timer is stopped and reset when the intermediate level sensor (25) is activated.  9.- Installation for purifying charged liquids according to claim 5, characterized in that it comprises a receiving tank (19) of purified liquid originating from the hydrocyclone (14), housed in the tank of the separator (6)  10.- Installation for purifying charged liquids according to any one of claims 5 to 9, characterized in that it comprises, at the lower part of the conical part (8) of the separator tank (6), a deflector (29) masking the orifice (27) of said conical part so as to widen the suction of the charges.