FR2719085A1 - Device for regulating the operation of a drain-siphon. - Google Patents

Abstract

The regulator consists of a regulating and re-charging element (5,7) comprising a tube (5) with a lower U-shaped end (6) which is full of water and is submerged in the reservoir. The upper end fits inside a bell (7) which has both ends closed and a perforated wall (8) close to the submersion point of tube. The tube is also connected to a regulating duct (9) with a hook-shaped upper end, the tip of which lies below the level of the top of the tube. The regulating/re-charging element is fixed to the top of the siphon, and its perforated wall section lies on a level with the top of the siphon's hook-shaped outlet end.

Description

DEVICE FOR PROVIDING REGULATION OF

OPERATION OF A DRAIN - SIPHON.

  The invention relates to a device intended to allow the regulation of the operation of a drain-siphon. Traditionally, deep soil drainage is carried out by siphoning off the water collected using one or more drains placed in the ground. This drainage is carried out either by pumping,

  either by gravity drainage when this is possible: sub-drains

  horizontal, trenches or draining walls, the water possibly being able to be pumped in the case of trenches or walls if

  gravity evacuation is not possible.

  With regard to pumping, drainage leads to subjections

  operating costs, and therefore maintenance at high cost price.

  As for the sub-horizontal drains, they require the appropriate relief conditions and, moreover, are not adapted to depths

important.

  In order to overcome these various drawbacks, it has been proposed for example in the document FR-A-2 593 203 to carry out a pumping by means of a siphoning pipe put in place in a drain implanted at

  proximity to a vertical drop, allowing geometrically siphoning.

  This document recommends in particular to avoid defusing the siphon, to install the drain at a permanent water tank in which the upstream end of the siphoning pipe is immersed, and also to immerse the downstream end of said pipe siphoning at a permanent water tank, the upper level of which is advantageously at the same level as that of the permanent upstream water tank. It also recommends, for the same purpose, to provide the downstream end of the siphoning pipe in the form of a butt, the end of which is also at the upper level of the permanent water tank. These arrangements are obviously an improvement over the devices known to date. However, they do not allow

  make these drainage devices completely non-defusable.

  When the water, in equilibrium at atmospheric pressure,

  goes up in the ascending branch of the siphon, it drops pressure.

  As a corollary, it releases part of the dissolved gas in the form of microbubbles. In addition, at the level of the descending branch of said siphon, there is a phenomenon of coalescence, that is to say that the microbubbles come together to form bubbles of larger dimensions. They are then subjected on the one hand, to the buoyancy of Archimedes, tending to cause the bubbles to rise to the level of the siphon itself, and on the other hand, to a hydraulic force inherent in

  the flow of the water stream, directed along said flow.

  In fact, if the flow is sufficient, the bubbles are conveyed to the outlet. On the other hand, if it reaches a critical value, the Archimedes' thrust tends to prevail over the hydraulic force, and the bubbles go back to the high point of the siphon where they accumulate and can

  cause defusing it.

  One of the objects of the invention is to stop the flow rate of the siphon when it reaches said critical value. In addition, it also relates to the re-priming of the siphon when the hydraulic head renewed in the borehole at which the drain is installed becomes sufficient to be able to cause at the level of the siphon, a turbulent regime suitable for

  remove the air bubble that has accumulated there.

  In fact, the invention provides a device for regulating the operation of a drain-siphon, the upstream and downstream ends of which continuously plunge into a permanent reservoir of liquid, and

especially water.

  It is characterized in that one of the ends of said siphon is provided with a member intended to stop the drainage when the flow rate reaches a minimum threshold called "critical rate", said member being further intended to re-prime the siphon by hunting effect,

  when the drainage has been interrupted.

  This organ consists of a tube on the one hand, the U-shaped lower end of which is full of water in normal operation and plunges into said reservoir at which the organ is located, and the upper end of which extends vertically within a bell closed at its two ends and having a screened base in the vicinity of the place of installation of the tube on the reservoir, said tube being furthermore connected at the same level to a regulation pipe, the free upper end, in the shape of a butt ends at a level

  lower than the upper level of said tube.

  According to a first embodiment of the invention, said member is fixed at the upstream end of the siphon, the lower end of the strainer base of the bell being at the top of

  the downstream end in the shape of a butt of the siphon.

  According to another embodiment of the invention, said organ is implanted at the downstream end of the siphon, said end terminating at the upper level of the strainer base of the tube constituting said organ, within a peripheral tube coming to bear on the permanent downstream water tank, the upstream end of the siphon at the level of which the drain is installed having a screened base, the lower level of which corresponds substantially to the level of introduction of the downstream end

of the siphon in said organ.

  The manner in which the invention can be carried out, and the advantages which ensue therefrom, will emerge more clearly from the following exemplary embodiments,

  given as an indication and not limiting in support of the appended figures.

  Figure 1 is a schematic representation of a siphon of a

known type.

  Figure 2 shows the device according to the invention in place

  at the upstream end of the siphon.

  Figure 3 shows the device according to the invention in place

  at the downstream end of said siphon.

  There is shown in Figure 1 a sectional view showing a single drain. This drain is installed at the level of a borehole (30), emerging at its upper end by a look at the level by

example of a road (31).

  This drain consists of a siphoning pipe (3), the upstream end (32) of which continuously plunges into a reservoir (1) permanently filled with water, and the downstream end (33) of which also plunges permanently in a water tank (34), the upper level of the two water tanks, respectively (1) and (34) being

about the same level.

  Advantageously, the siphoning tube (3) is placed in the slope so that it is frost-free on the one hand, and out of the sun on the other hand. According to the first embodiment shown in connection with Figure 2, the permanent water tank (1) at which plunges the upstream end of the siphoning tube (3), is closed by a plug (2) in the upper part . This plug is therefore traversed on the one hand, by the siphoning tube (3) and on the other hand, by a tube (4) for bringing said permanent water tank (1) to atmospheric pressure, said tube

  (4) being for example constituted by a rilsan.

  In addition, and according to a fundamental characteristic of the invention, the plug (2) is also traversed by a tube (5), the lower end (6) of which dips into the permanent water tank (1) and has a U-shape, said U-shape (6) being permanently filled

of water in normal operation.

  According to another fundamental characteristic of the invention, the tube (5) is surmounted outside the permanent water tank (1), that is to say above the plug (2) by a bell constituted by a tube (7), concentric with the tube (5), closed at its upper end and strainer

at its base in (8).

  In addition, the tube (5) is connected at the level and through the plug (2) to a regulation pipe (9), the free upper end of which is in the form of a butt (10) ends at a level lower than the upper level.

  of the tube (5) within the bell (7).

  In parallel and in this embodiment, the downstream end (11) of the siphoning tube (3) ends in the shape of a butt, the top (12) of which is wedged at the same horizontal level as that of the plug (2) of

the upstream end.

  The operation of this device will be described below in more detail. In operation, the bell (7) and the tube (5) are primed: the water from the borehole (13) located above the strainer (8), flows into the bell (7) and the tube (5) , and supplies the permanent water tank (1), the latter being

pumped through the siphon hose.

  The water level in the pipe (4) is characteristic of the load

  hydraulic in the permanent water tank (1).

  When the flow rate decreases, the water column at the drain (13) ends at a level slightly lower than the high level of the screened base (8) of the bell (7), and air rushes into the bell (7) then in the tube (5) and the two are defused; the permanent water tank (1) is no longer supplied, but continues to empty until reaching a critical hydraulic load on the siphon (3), load at which the descending part of the buttstock shape swallows (11 ) is defused: this defuse is connected with the rising of the bubbles at the top of the siphon. The latter then stops flowing, the water level in the downstream part of the siphon (3) positioning itself at equilibrium in the ascending part of the crook shape (11) in relation to the water level at l '' stop in the

permanent water tank (1).

  Then, when the water column rises within the drain (13), the siphon no longer discharging, the hydraulic load increases, resulting in compression of the air contained in the bell (7) first, and in the tube (5) on the other hand, said compression reaching a value sufficient to suddenly evacuate the water contained in the U-shape (6) at the lower end of said tube (5), thus causing a flushing effect by abrupt feeding of the permanent water tank (1), and creating a turbulent regime, capable of breaking the bubble located at the high point of the siphon, leading this bubble to the outlet of the siphon, and therefore

reboot of it.

  In the embodiment shown in Figure 3, the device according to the invention is positioned at the downstream end of the siphoning tube. In this specific case, the upstream end is treated in a permanent simple water tank (1) placed in the drain (13), in which the end (32) of the siphoning tube is immersed and whose upper level is wedged on the horizontal level (23) serving as a later reference. In parallel, said permanent water tank (1) is extended above this level (23) by a screened portion (35), allowing the penetration of water into the permanent water tank, and being able to

constitute a second filter.

  The downstream end of the siphon is terminated by a curved shape (37) connected to its upper part (15) at level (23) on a tube (16), for example made of polyvinyl chloride (PVC), said tube (16) being open at its upper part (17), and closed at its lower part (18) by a

plug (36).

  Said cap (36), placed on the permanent water tank

  downstream (16), is crossed by a tube (19), the lower end of which

  te a form of U (20) always full of water in normal operation.

  The tube (19) is surmounted by a cylindrical tube forming a bell, closed at its upper part (21), and strainer at its base (22) at

its junction with the plug (36).

  Finally, a regulation pipe (14) is connected to said tube (19) at (24), that is to say at the level of the plug (18). The free end (25) of this regulation pipe is in the form of a butt, and penetrates inside the upper part of the tube (16) to a level below the upper level of the tube (19). According to a characteristic of the invention, the free end of the U-shape (20) of the tube (19) ends at a level lower than that of

  the strainer end (22) of the bell (21).

  In this way, when the "critical flow" is reached, the downstream flush thus constituted is defused, the difference in level between the upper part of the strainer part (22) and the upper orifice of the U-shaped portion (20) being chocked so that the flow of the bell (21) and the tube (19) is equal to the critical flow of the main siphon (3), when the water level in the

  tube (16) reaches the upper part of the screened part (22).

  When the drain (13) is recharged, the water rises in the tube

  (16), the water arriving from the end (37) of the siphoning tube (3).

  This rise of the water in the tube (16) generates the pressurization

  an air bubble at the top of the bell (21), and in the tube (19).

  When the tube (19) evacuates all of its water, the gas bubble under pressure expands, priming the bell (21), thus creating a rapid and brutal emptying of the tube (16). This creates a hydraulic load on the siphon (3) between the hydraulically charged drain and the downstream of the siphon.

  brutally discharged by the effect of the emptying of the downstream flush.

  The purpose of the regulation pipe (9) respectively (14) is to let the water rise in the bell (7) respectively (21) when it rises in the tube (5), respectively (16), the air expelled in front it being able to borrow the pipe (9), respectively (14). When the water level in the tube (13), respectively (16) reaches the lower part of the connection area of the pipeline (9) respectively (14) with the plug (2, 36), the air does not can no longer escape through said pipe (9,14), and begins to pressurize at the top of the bell (7),

  respectively (21) and in the pipe (5, 19).

  By adjusting the value of the priming load by the geometry of the flush, a hydraulic load is created, generating the expected turbulence regime and causing the complete bleeding of the bubbles accumulated at the point

  top of the siphoning pipe (3), and therefore re-priming the siphon.

Claims (4)

  1 / Device for regulating the operation of a drainsiphon, the upstream (32) and downstream (33) ends of which continuously plunge into a permanent reservoir of liquid, and in particular water, respectively (1) and (34) , characterized in that one of the ends of said siphon is provided with a regulation and priming member (5, 7, 19, 21) intended to stop the drainage when the flow rate reaches a minimum threshold called "flow rate" critical ", said member being further intended to re-prime the siphon by flushing effect, when the drainage has been interrupted.  2 / Device according to claim 1, characterized in that the regulating and re-priming member consists on the one hand, of a tube (5, 19), the lower end of which is U-shaped (6, 20) is full of water in normal operation and plunges into said reservoir (1, 34) at the level of which the member is implanted, and the upper end of which extends vertically within a bell (7, 21) closed at its two ends and having a screened base (8, 22) in the vicinity of the place of installation of the tube (5, 19) on the reservoir (1, 34), said tube being furthermore connected at the same level to a regulation pipe (9, 14), whose free upper end (10, 25), in the shape of a butt ends at a lower level   at the upper level of said tube (5, 19).   3 / Device according to claim 2, characterized in that said regulating and re-priming member is fixed at the upstream end (32) of the siphon (3), the lower end of the screened base (8) of the bell (7) located at the top (12) of the downstream end   (33) in the shape of a butt (11) of the siphon (3).   4 / Device according to claim 2, characterized in that said regulating and re-priming member is located at the downstream end (33) of the siphon (3), said end (37) of the siphon (3) leading to the level (15 ) upper of the screened base (22) of the tube (19) constituting said member, within a peripheral tube (16), coming to rest on the permanent downstream water tank (34), the upstream end ( 32) of the siphon (3) at the level of which the drain is implanted having a strainer base (35), the lower level (23) of which corresponds substantially to the level   introduction (15) of the downstream end (37) of the siphon in said organ. DEPOSITOR: RESS GROUP   AGENT: LAURENT & CHARRAS Cabinet