FR2717265A1 - Seabed device for measuring various properties of seawater - Google Patents

Abstract

Device for measuring the physico-chemical parameters of seawater, comprising a number of blocks (66) assembled together in such a way as to define a feed (72) and a recycling (73) pipe for seawater. Certain blocks also contain a radial internal pipe (85) opening into the feed pipe. Means for measuring a parameter of the water such as pH, conductivity, temperature, or dissolved oxygen is embedded in the wall of the radial pipe.

Description

 The present invention relates to a device intended for measuring physico-chemical parameters of a liquid such as sea water or fresh water.

 Currently, the measurement of physico-chemical parameters of seawater is generally carried out by measuring devices after sampling seawater in containers.

 This known process is not only expensive, but requires numerous human interventions to ensure regular measurements of the physico-chemical parameters of seawater.

 The object of the present invention is to eliminate the above drawback of the known method by proposing a device intended for measuring physicochemical parameters of seawater and which is characterized in that it comprises a certain number of assembled blocks to each other so as to define two internal suction and seawater delivery pipes respectively, some of the blocks each comprising an internal radial pipe opening into the suction pipe and a sensor means of a parameter of l seawater, such as pH, conductivity, seawater temperature or the level of dissolved oxygen in it, housed in the radial internal duct.

 Advantageously, at least one of the assembled blocks of the device comprises two substantially parallel internal conduits opening into the internal suction conduit and intended to be connected to an external seawater bypass pipe to an external sensor means for measuring d 'other physico-chemical parameters of seawater such as for example its chlorophyll content or its nitrate or sulfate level.

 In addition, at least one of the aforementioned assembled blocks comprises two substantially parallel internal conduits opening into the internal discharge conduit and intended to be connected to an external seawater bypass conduit to an external sensor means measuring, for example , the seawater flow.

 The block located downstream of the aforementioned measuring blocks relative to the direction of circulation of the sea water in the internal suction duct comprises two substantially parallel internal ducts opening respectively into the internal suction and discharge ducts and allowing connection a hydraulic pump in series in the suction and discharge lines.

 Preferably, the aforementioned blocks are fixed to each other in a removable and interchangeable manner by mechanical fixing means.

 Each mechanical fixing means from one block to another comprises a fixed tab hinged to a block and foldable manually to lock to a square piece integral with the other block.

 The assembled blocks are mounted on a floating body, such as a buoy, moored to the seabed and form part of a hydraulic circuit comprising, in series, a submerged seawater sampling tube, the internal suction duct, the hydraulic pump mounted on the floating body, the internal discharge conduit and an immersed seawater discharge tube.

 Advantageously, the aforementioned blocks are mounted by threading on support rods fixed to the floating body.

 The device also comprises a submerged tubular body containing several sampling tubes opening respectively into through openings in the wall of the tubular body at different depths and a multi-channel hydraulic distributor on the floating body, mounted in the aforementioned hydraulic circuit and controlled by a central unit. of control so as to periodically select, for determined durations corresponding to phases of seawater withdrawal, a series of different pairs of tubes from the available tubes of the tubular body, one of the selected tubes of each pair constituting the sampling of the hydraulic circuit and the other tube of this pair constituting the discharge tube of the hydraulic circuit.

 The control center performs at each seawater sampling phase at least one measurement of a physico-chemical parameter of seawater supplied by at least one of the sensors associated with a determined block.

 The control unit also permanently monitors the flow of water in circulation in the hydraulic circuit from a flow meter associated with one of the assembled blocks and modifies the supply voltage of the hydraulic suction pump in the event of loss of flow so as to maintain a constant flow of water in the hydraulic circuit.

 The central control unit also performs a measurement of seawater temperature and pressure at each phase of seawater sampling from a temperature and pressure sensor means located at each sampling opening of the immersed tubular body.

 The control center stores all the measured values of the physico-chemical parameters during several measurement cycles and transmits them periodically, for example by radio, to a coastal management installation.

 The device also includes two chlorinating means mounted in series in the hydraulic circuit respectively upstream of the assembled blocks and downstream of the suction pump and a hydraulic reversing means between the two chlorinating means and the assembly of assembled suction pump units. by the control center outside the abovementioned sampling and measurement cycles to clean all the parts of the hydraulic circuit.

The invention will be better understood and other objects, characteristics, details and advantages thereof will appear more clearly in the explanatory description which follows, made with reference to the appended schematic drawings given solely by way of example illustrating several embodiments of the invention and in which
- Figure 1 shows the sampling and measuring device according to the invention associated with a floating body moored to the seabed
- Figure 2 is a top view along arrow II of Figure 1
- Figure 3 shows a variant of mooring of the floating body by the sampling device
- Figure 4 is an enlarged view of the connection of the upper end of the sampling device to the floating body
- Figure 5 is a top view along arrow V of Figure 4
- Figure 6 shows a hydraulic circuit forming part of the device of the invention
- Figure 7 is a sectional view along the line
VII-VII of Figure 8 and Figure 7A is a partial perspective view along arrow VII A
- Figure 8 is a sectional view along the line
VIII-VIII of figure 7
- Figure 9 is an alternative embodiment of the sectional view of Figure 8
- Figure 10 is an enlarged detailed view of the part circled in X of Figure 4
- Figure 11 is a top view showing an example of installation on the floating body of different components of the hydraulic circuit
- Figure 12 is a perspective view with partial cutaway of a cell for measuring physicochemical liquid parameters of the measuring device of the invention
- Figure 13 is a perspective view with partial cutaway of a hydraulic distributor of the sampling and measuring device
- Figure 14 is a partially exploded perspective view of a hydraulic inverter of the hydraulic circuit of the sampling and measuring device; and
FIG. 15 shows in detail a piston forming a drawer used in the hydraulic distributor of FIG. 13.

 Referring to Figures 1 and 2, the reference 1 designates a floating body, such as a buoy, moored at the bottom of the sea, in this case, by three mooring cables 2, two of which are formed by chains. The two mooring chains 2 have their upper ends hingedly connected to the floating body 1 and their lower ends fixed to dead bodies 3.

 According to the invention, as will be explained later in particular with reference to FIGS. 7 to 9, the third mooring cable 2 is preferably housed in a submerged tubular body 4 forming part of a device for sampling sea water at different depths. This cable 2 extends over the entire length of the tubular body 4 and has its lower end projecting from the body 4, connected to a ballast 5 via a swivel 6, the ballast 5 being connected to a dead body 3 by means of a chain 7. As shown in FIGS. 4, 5 and 10, the cable 2 has its upper end projecting from the tubular body 4 and fixed in a relatively heavy intermediate take-up part 8, by example of a hundred kilos, itself hingedly connected to the top of a triangular plate 9 connected to the floating body 1 by two anchor chains 10. The upper end of the cable 2 comprises, integral with the latter , a part forming a corner 11 force fitted into a fixing plate 12 bearing at the bottom of a cavity 13 produced in the intermediate part 8 and closed by a plate 14 connected articulated to the rigid plate 9 and fixed to the part 8 by appropriate means, t els as fixing screws (not shown), to allow access to the corner piece 11 when necessary. Of course, other methods of fixing the cable 2 in the intermediate piece 8 are possible without departing from the scope of the invention. Thus, when the cable 2 consists of braided fibers, the fixing of this cable is carried out by a termination forming a splice instead of the part forming a corner.

 The seawater sampling device also comprises a number of seawater sampling tubes 15 passing longitudinally through the immersed tubular body 4 and having their lower ends opening out, at different depths, respectively in openings 16 made at the through the side wall of the body 4. FIG. 6 schematically represents four sampling tubes 15 in the body 4, but it is understood that a different number of such tubes can be provided without departing from the scope of the invention. The upper ends of the four sampling tubes 15 are respectively connected to four inlets / outlets of a hydraulic distribution means 17 mounted on the floating body 1 and which will be described later.

 The sampling tubes 15 are respectively housed in sleeves 18 extending in the tubular body 4 along the latter. These sleeves 18 respectively open into chambers 19 defined in line with the openings 16 of the body 4. More precisely, each chamber 19 is defined in a block of practically sealed material, such as low density foam, housed in the tubular body 4 being attached to a corresponding portion of the side wall of the body 4.

The block 20 has, for example, an approximately parallelepiped configuration with two opposite substantially curvilinear faces, one of which conforms to the internal wall of the body 4, one 20a of the side walls of the block 20 being substantially perpendicular to the wall of the tubular body 4 being crossed by the sheath 18 so that the latter, with its sampling tube 15, open into the chamber 19 communicating with the associated opening 16 of the tubular body 4.

 Sleeves 21, identical to the sleeves 18, are also provided in the tubular body 4 and mounted in the latter so as to form pairs of sleeves 18, 21 each of which opens into a same corresponding chamber 19. As shown in the view in section of Figure 8, the sleeves 18, 21 are distributed substantially on the same circumference being two by two close to each other so as to open into the corresponding chamber 19 through the same wall 20a of the block 20 defining this room. The sleeves 21 are each traversed by an electrical conductor 22 electrically connected to a sensor means 23 for water temperature and pressure and housed in the sleeve 21 in the vicinity of its end opening into the chamber 19. Such a sensor means, known in does not have to be detailed. In the illustrated example where the sampling device comprises four sampling tubes 15, four pairs of sleeves 18, 21 are thus provided with each pair of sleeves 18, 21 opening into a chamber 19 at a depth different from that of the other pairs of scabbards 18, 21.

 Preferably, pairs of empty sleeves 24, that is to say without sampling tubes and conductors 22, occupy the space left free between the sampling chambers 19 into each of which opens a pair of sleeves 18, 21 and the end lower part of the immersed tubular body 4.

The sleeves 24 of each pair are fixed at their upper ends in the side wall 20b parallel to the side wall 20a of the block 20 and have their lower ends closed. These pairs of additional sleeves 24 are used to improve the buoyancy of the tubular body 4 by filling them with air or foam.

 The tubular body 4 also comprises a central sheath 25 extending all along the body 4, surrounding the mooring cable 2 so as to allow the latter to slide freely in the sheath 25. If necessary, the cable 2 is surrounded by a protective plastic sheath to protect it against friction in the central sleeve 25.

 The sleeves 18, 21 and 24 are held in position in the tubular body 4 by wedges 26 of foam material interposed at regular intervals along the body 4 between the central sleeve 25 and the sleeves 18, 21, 24 as shown in Figures 7 and 8. If necessary, such shims can be interposed between these sleeves and the body 4.

According to the variant embodiment shown in FIG. 9, the sleeves 18, 21 and 24 are held in the tubular body 4 by foam material filling all the free space defined in the body 4 between the sleeves 18, 21, 24 and the sleeve central 25.

 In addition, the sleeves 18, 21, 24 can extend in the body 4 parallel to it but, preferably, these sleeves extend helically in the body 4 along the latter to avoid any excessive tension which may exercise on the sampling tubes 15 and / or the electric cables 22.

 FIG. 10 schematically represents the way in which the sleeves 18, 21 with the tubes 15 and the conductors 22 not shown for reasons of clarity, are separated from the central sleeve 25 and from the cable 2 inside the intermediate part 8 which comprises , integral with the latter, a sleeve 28 in which the upper end of the tubular body 4 is fixed. As can be seen from this figure, the sleeves 18, 21 are introduced into corresponding holes in the part 8 deviating from the central sleeve 25 in the part 8 to project from the latter in a flexible pipe 29 fixed in a sleeve 30 integral with the part 8. The pipe 29 passes through the floating body 1 through a well 31 thereof and is fixed to the body 1 by a piece forming an end piece 32 allowing the connection of the sampling tubes 15 by means of hydraulic distribution 17. Thus, the sleeves 18 containing the tubes 15 stop in the part 32 likewise that the sleeves 21 whose electrical conductors 22 are electrically connected to a central control unit 33 as symbolized by the large arrow in FIG. 6. The role of the central control unit 33 will be explained later. Preferably, the well 31 is made laterally to the floating body 1 so as to allow the disassembly of the pipe 29 from this body after removal of a sliding sleeve 34 ensuring the fixing of the pipe 29 at the point of entry into the lateral well 31 and the stiffening of this pipe in the well.

 The tubular body 4 is provided with external sleeves 35 of a number equal to the number of water sampling openings 16. In the present case, four sleeves 35 are provided since there are four sampling tubes 15 in the body submerged 4.

 FIG. 7 shows that each sleeve 35 comprises a fixed part 36 fixed around the tubular body 4 for example by gluing and a removable part 37 fixed coaxially on the fixed part 36 for example by means of fixing screws (not shown). The removable part 37 is slid over the fixed part 36 before fixing on the latter to come into abutment against a shoulder 36a of the fixed part 36. The two parts 36, 37 of the sleeve 35 have two superimposed openings 36b and 37a extending over at least a half-circumference, one part of which covers the opening 16 of the tubular body 4 for fluid communication with the chamber 19. The removable part 37 supports a strainer 38 made of cupro-nickel material. The dismantling of the part 37 of the fixed part 36 makes it possible from time to time to clean the corresponding strainer 38 or, if necessary, to replace it, and to access the suction chamber 19. The sleeves 35 are distributed equidistantly along the tubular body 4 with the lower sleeve 35 as close as possible to the lower end of the body 4. In the three-chain anchoring configuration shown in FIGS. 1 and 2, the sleeves 35 are made in a material, such as low density foam, ensuring a certain buoyancy of the immersed tubular body 4 so as, in combination with the unused sleeves 24 filled with foam or air, to avoid the rage of the immersed body 4 at the seabed.

 The tubular body 4, the sleeves 18, 21, 24, 25 and 29 and the sampling tubes 15 are made of a material, for example PVC, providing this assembly with a certain flexibility. For a body 4 for example with a length of 25 meters, the radius of curvature of this body is at most 2 meters.

 The hydraulic distribution means 17 connects simultaneously, at a given instant, and in series, two sampling pipes 15 to a hydraulic circuit 39, of which the distribution means 17 is a part, so as to carry out the measurement of physico-chemical parameters d seawater sampled through one of the sampling tubes 15 to a determined depth and to discharge the analyzed seawater through the other of the selected sampling tubes to another determined depth.

 To this end, as shown in FIG. 6, the hydraulic circuit 39 comprises, connected in series from upstream to downstream of the two tubes 15, respectively for suction and discharge of seawater, a first chlorinator means 40 connected at the outlet of the multi-channel distributor means 17, a cell 41 intended for measuring the physico-chemical parameters of seawater withdrawn, a hydraulic suction pump 42 and a second chlorinator means 43 connected to the inlet of the multi-channel distributor means 17. The means chlorination 40, 43, known per se, are intended for the protection of the hydraulic circuit against bio-fouling. Each chlorinator means 40, 43 thus consists of a circulation chamber equipped with parallel plates, for example in platinum titanium, and placed in series on the hydraulic circuit. The control unit 33 is adapted to apply a continuous voltage between the plates for the production of chlorine for cleaning the entire hydraulic circuit. The tension between the plates is adjustable taking into account for example the environment in which the sampling device is located, the seasons or any other influencing parameter and is in any case fixed for the generation of an optimal chlorine level in particular in the cell. and the delivery pipes. This ensures undisturbed operation in particular of the measuring cell. It may be desirable under certain operating conditions to temporarily cut off the supply to one of the chlorinator means 40, 43. This is particularly the case of the chlorinator means 40 upstream of the measuring cell and which must be cut during the measurement of the pH of seawater so as not to distort this measurement. The hydraulic circuit 39 also includes a hydraulic reversing means 44 normally having one of its internal conduits in series between the chlorinator means 40 and the measurement cell 41 and another internal conduit in series between the suction pump 42 and the chlorinating means 43. The hydraulic reversing means 44, which will be described later, is controlled by the control unit 33 so as to periodically switch the direction of water circulation in the pipes between the measuring cell 41 and the means multi-channel distributor 17 so that the entire hydraulic circuit 39 is cleaned and protected against biofouling.

 The multi-channel distributor means 17 is shown in detail in FIG. 13 and comprises a box 45 in which are mounted five cylindrical drawers 46 controlled respectively by five electric motors 47 themselves controlled by the central control unit 33 and fixed to the box 45. Each drawer 46 is thus actuated by an independent motor 47 so as to occupy three possible stable positions, a suction position, a discharge position and a neutral position. The first four drawers 46 starting from the right towards the left in view of FIG. 13 are associated respectively with four conduits 4851 connected at their ends to the four sampling tubes 15 by means of the piece forming end piece 32 and having their ends opposite, each ending in a bifurcation, only the bifurcations of lines 48-50 being shown. Thus, each bifurcation comprises a branch 48a-50a perpendicular to the corresponding pipe 48-50 and a curved branch 48b-50b extending the corresponding pipe 48-50. The bifurcations of the conduits 48-51 are connected to the housing 45 of the distributor means 17 by means of connection end pieces 53 so as to lead respectively into upper internal conduits produced in the housing 45 and bearing the reference 54 for those associated with straight branches of each bifurcation, such as 48a-50a, and reference 55 for those associated respectively with curved branches such as 48b, 49b, 50b. Each drawer 46 is interposed between two parallel upper internal conduits 54, 55 of a corresponding conduit 48 to 51 and two parallel lower internal conduits produced in the housing 45 respectively in extension of the upper internal conduits 54, 55 and bearing the references 56 and 57 The lower conduits 56 open into a common rectilinear conduit 58 produced in the housing 45 and having one of its ends closed while its opposite end opens out of the housing 45. A connection end piece 59 is fixed in the through end of the conduit 58. Likewise, the lower internal conduits 57 open into a rectilinear internal conduit 60 produced in the housing 45 parallel to the conduit 58 and having one of its ends closed while its opposite end opens out of the housing 45 A connection endpiece 61 is fixed in the through end of the conduit 60. The fifth drawer 46 is associated with the pipe 52, one end of which is connected to a sampling pipe (not shown) intended to take the seawater from the surface. This sampling pipe is not part of the immersed tubular body 4 and can be optional. As for lines 48-51, line 52 comprises a bifurcation having its straight branch and its curved branch communicating, by means of connection end pieces similar to end pieces 53, respectively in two upper internal conduits 54 and 55 which can be put in communication with respectively two lower internal conduits 56, 57 via the corresponding slide 46.

 FIG. 15 more clearly represents the configuration of each drawer 46 which comprises a tapped longitudinal blind hole 46a into which is screwed a drive shaft 62 with rectilinear translation movement controlled by the corresponding electric motor 47. The drawer 46 also includes two grooves spaced annulars 46b, 46c, each intended to connect two upper 54 and lower internal conduits 56 or two upper 55 and lower internal conduits 57 depending on whether the drawer 46 occupies a determined position respectively for seawater suction or discharge seawater. At any given time, one of the drawers 46 is controlled by its corresponding electric motor 47 so that the annular groove 46b is disposed between two upper 54 and lower 56 internal conduits associated with a specific conduit 48 to 52 relating to drawer 46, while the other drawers 46 occupy a position for closing the passa ge of water between the other upper and lower internal conduits 54, 56 by means of cylindrical bearing surfaces 46d or 46e. In this way, only one of the pipes 48 to 52 is selected in seawater suction mode and FIG. 13 shows by way of example that only the pipe 50 is chosen to suck in seawater in the direction indicated by the arrows A. At this same instant, the annular groove 46c of one of the drawers 46 associated with one of the lines 48 to 52, but which is not the one already selected as the line of suction, is interposed between two upper 55 and lower 57 internal conduits, the passage of water between the other internal conduits 55, 57 being prevented by cylindrical surfaces 46f of the drawer 46. One thus selects one of the conduits 48 to 52 to ensure the discharge of sea water from the pump 42. In the example shown in FIG. 13, the discharge of sea water takes place in the direction indicated by the arrows R through the pipe 52 .

The pipes 48 to 52 are thus associated with the sampling tubes 15 intended to withdraw or discharge sea water to different depths. By way of example, pipes 48 to 52 correspond to withdrawals or backflows of twenty meters, fifteen meters, ten meters, five meters and zero meter respectively (surface of the sea). The operating principle of the multi-channel distributor means 17 is therefore, at any given time, to select a sampling tube 15 for sucking the sea water towards the cell 41 and another sampling tube 15 for discharging the sea water to a depth different from that where the sampling takes place.

 The chlorinating means 40 is connected to one end of a pipe 63, the opposite end of which is fitted into the connection end piece 59 of the dispensing means 17 while the other chlorinating means 43 is connected to a pipe 64 fitted to its end. opposite in the connection endpiece 61 of the means 17.

 The connection between an electric motor 47 and the corresponding slide 46 to allow the drive in translation to the desired position of the latter can be effected by a toothed wheel driven by the shaft of the motor 47 in mesh with a part forming a fixed rack of the shaft 62 of the drawer 46.

 The position of each drawer 46 is controlled by position detectors 65 housed in the housing 45 and of the kind with two binary contacts produced respectively by two elastic contact blades 65a with cylindrical studs 65b cooperating with three successive annular grooves 46g of each drawer 46 to indicate the suction, discharge or neutral position of this drawer. The detectors 65 are of course electrically connected to the control center 33 to provide it with information relating to the position of each drawer 46.

 The cell 41 for measuring physico-chemical parameters of seawater is shown in detail in FIG. 12 and comprises a certain number of blocks or modules 66 each having a particular function, removably attached to each other and mounted on four rods of parallel supports 67 fixed on a box defined later and itself fixed on the floating body 1 so as to allow mounting by threading of the blocks 66.

 The mechanical means for fixing two adjacent blocks 66 include a lug 68 hingedly attached to a block 66 and a square piece 69 attached to the adjacent block 66 so that the hinged lug 68 can be folded down manually on the square piece 69 and lock into it automatically. Such a fixing method, widely known per se, need not be more detailed and, of course, other mechanical fixing methods between adjacent blocks 66 allowing their separation are conceivable.

 Each block 66 comprises two separate internal conduits 70 and 71 forming, when the blocks 66 are assembled, a longitudinal internal suction conduit 72 and a longitudinal internal discharge conduit 73. The two longitudinal conduits 72 and 73 open out through a upper block 66 in view of FIG. 12 respectively in two connection end pieces 74, 75 integral with the upper block 66 and to which are connected respectively two suction 76 and discharge 77 pipes which are connected at their opposite ends respectively to two end pieces 78 , 79 integral with the housing 80 of the hydraulic reversing means 44.

 FIG. 12 shows seawater sucked into the conduit 72. Of course, other types of sensors for measuring physicochemical parameters can be integrated in the blocks 66. The sensors 81-83 are connected to the control unit 33 .

 FIG. 12 also shows that the last block 66 has an internal radial duct 87 communicating with the longitudinal duct 72 and with an external pipe 88 for connection to the suction pump 42. The latter discharges seawater through a pipe external bypass 89 connected to an internal radial conduit 90 produced in the block 66 and opening at the lower end of the internal delivery conduit 71. The pump 42 is detachably fixed to the penultimate block 66 by means of 'a fixing lug 91 screwed to this block.

 The last block 66 is a seawater settling block.

 Other blocks 66 can be added to those defined above. Thus, the measuring cell 41 can comprise at least one block 66 comprising two parallel radial internal conduits communicating with the suction conduit 72 and connected to an external bypass conduit allowing the seawater to be brought to an external sensor. measurement of a physico-chemical parameter of seawater such as for example the sulphide level of seawater, the turbidity thereof, or the chlorophyll level, the level of nitrate in water These sensors, instead of being placed upstream of the pump 42, can also be placed downstream of this by providing two parallel radial internal conduits in each corresponding block 66, opening into the longitudinal discharge conduit 73 and connected to an external bypass line in which the external sensor is located.

 FIG. 14 shows in detail the hydraulic reversing means 44, the housing 80 of which contains two cylindrical drawers 92 with movement controlled in translation by two electric motors 93 fixed to the housing 80 and identical to the motors 47 of the distributor means 17. The motors 93 are controlled by the control center. The two drawers 92 occupy two stable positions, namely a suction position and a discharge position controlled by two detection means 94 housed in the housing 80 and of the sensor type with two binary contacts comprising two contact blades 94a each ending by a cylindrical stud 94b cooperating with two successive annular grooves 92a, 92b of a drawer 92. These detection means 94 are electrically connected to the control unit 33. Each drawer 92 also includes two separate annular grooves 92c and 92d each defined between two cylindrical seats 92e of the drawer 92. At a given position of a drawer 92, the annular groove 92c is interposed between two upper 95 and lower 96 internal conduits produced in the housing 80 with the conduit 96 opening at one end of a conduit internal rectilinear 97a opening into the connection piece 78. The upper conduit 95 associated with a slide 92 drawer uche in a nozzle 98 integral with the housing 80 and to which is connected the straight branch 99a of a bifurcation of a pipe 99 connected at the outlet of the chlorinator means 40. The upper internal conduit 95 associated with the other drawer 92 also opens into a end piece 98 to which the straight branch 100a of a bifurcation of a pipe 100 connected to the inlet of the chlorinating means 43 is connected. The annular groove 92d of each drawer 92 can be interposed between two upper internal pipes 101 and lower 102 of so as to allow the passage of seawater in these conduits. Each lower duct 102 opens into a duct 97b parallel to the duct 97a and opens into the connection end piece 79. The two upper ducts 101 open respectively into two other end pieces 98 integral with the housing 80 and into which are respectively connected two curved branches 99b and 100b of the bifurcations of the two lines 99 and 100.

 The translational drive of each drawer 92 by the corresponding motor 93 is carried out in the same manner as for each drawer 46 of the multi-channel distributor means 17, that is to say by a mechanical connection with a toothed rack wheel between the shaft of the motor and the shaft 103 mechanically coupled to the drawer 92.

Normally, the two drawers 92 are positioned so as to ensure the suction of seawater according to the arrows
A and the sea water discharge following the arrows R.

In other words, the groove 92c of the drawer 92 furthest back with respect to FIG. 14 authorizes the passage of water sucked through the conduits 95, 96 and 97a while one of the cylindrical surfaces 92e of this same drawer obstructs the two internal conduits 101 and 102, and the groove 92d of the other drawer 92 is interposed between the two conduits 101 and 102 so that the pumped water circulates through the curved branch 100b with one of the cylindrical bearings 92e of this drawer obstructing any passage of fluid in the straight branch 100a. FIG. 14 represents the state of the reversing means 44 according to which the drawers 92 are positioned so as to reverse the direction of circulation of seawater in the pipes 99 and 100 in order to ensure that the entire hydraulic circuit is protected against bio-soiling. Of course, the reversal of the means 44, controlled from the control center 33, is carried out periodically outside of the normal operation of seawater withdrawal.

 FIG. 11 represents a mode of installation of the different means constituting the hydraulic circuit 39 in a housing 104, shown in the present case as being open, fixed on the floating body 1. The control unit 33 is also housed in the housing 104 .

 The operation of the sampling and measuring device already emerges from the description which has been made above and will now be explained.

 Each seawater sampling cycle is commanded and controlled by the central control unit 33. A complete seawater sampling cycle and measurement of all of its physico-chemical parameters is carried out on the five points sampling of different depths defined above (depths of zero meters, five meters, ten meters, fifteen meters and twenty meters) and is executed within a relatively short time, for example around 10 minutes.

A sampling and measurement cycle is carried out as follows
the central control unit 33 controls the multi-channel distributor means 17 so as to carry out a first sampling of seawater by selecting two tubes 15 respectively for suction and discharge. Thus, the drawers 46 of the dispensing means 17 are positioned by the central unit 33 so that this removal takes place for example at a depth of five meters and the delivery takes place at a depth of twenty meters. Under these conditions, the sea water is sucked to the depth of five meters through the corresponding sampling tube 15, circulates in the pipe 50 of FIG. 13 along the arrow
A, passes through the dispensing means 17 to then flow through the pipe 63. The sea water then passes through the chlorinating means 40, the pipe 99 of the reversing means 44, crosses the latter to then flow through the pipe 76 and lead to the inlet of the measuring cell 41. The seawater passes through the internal conduit 72 of the blocks 66 to end up at the pump 42 and is then discharged into the internal discharge conduit 73. The discharged seawater passes again the reversing means 44, circulates through the pipe 100 to then pass through the other chlorinating means 43 and end up at the dispensing means 17. The discharged seawater passes through the dispensing means 17 to circulate in the pipe 52 and then crosses the sampling 15 in seawater discharge mode at the determined depth of twenty meters. During this first sampling, the central control unit 33 is programmed to choose one of the sensors for measuring a physico-chemical parameter of the sea water flowing in the internal conduit 72 of the measurement cell 41. The sensor chosen can be for example that allowing the measurement of the dissolved oxygen level in seawater.

 Once the information from the measurement sensor associated with the first abovementioned sample has been recorded in a memory of the control center 33, the latter again controls the dispensing means 17 so that it selects two tubes from the five available tubes 15 in order to to start the second phase of seawater sampling and measurement of a new physico-chemical parameter thereof. Thus, the means 17 is controlled so as to take a seawater sample, for example from the surface of the sea (zero meters deep) and discharge the seawater to the depth of fifteen meters. As for the first sampling, the control unit 33 receives and stores the information relating to the new physicochemical parameter captured by the sensor chosen according to the program of the unit and which can for example be the sensor for measuring the conductivity of the water of sea flowing through the measuring cell 41.

 - The third, fourth and fifth sampling phases are then carried out successively under the supervision of the control center 33 which each time controls the dispensing means 17 so that a sampling and a discharge of seawater are always carried out at different depths. The control unit then successively records different values of physico-chemical parameters of seawater, such as for example the pH of seawater, its turbidity, the level of sulfide, chlorophyll or nitrate in seawater.

 Of course, the measuring device can operate with a number of sampling and measuring phases of a complete cycle different from that defined by way of example above and depending on the number of sampling tubes 15 used in the immersed tubular body 4 .

 In addition, the durations of the different sampling and measurement phases of each cycle can be different from each other, each sampling phase has a constant duration in time and the duration of a complete cycle is also constant. The duration of each phase can be variable and subject to the parameters measured at each sample or to temperature variations from one sample to the next, for example. Preferably, the order in which the samples are taken is also constant from one cycle to another. It is possible to provide at the end of the sampling and measurement phases of a complete cycle and before the start of a new cycle, a step of a predetermined period of time allowing operations such as control of the hydraulic reversing means 34 to be carried out. for a complete cleaning of the hydraulic circuit, change of supply of the hydraulic pump 42, cleaning of the electrodes of the chlorinating means, etc ...

 Furthermore, the control unit 33 can also be programmed to carry out a seawater pressure and temperature measurement cycle at each sampling depth by means of the corresponding sensor means 23 and this in parallel with the normal cycle of seawater sampling and measurement of its physico-chemical parameters.

 The device may also include a flow meter connected to a bypass line associated with a block 66 preferably downstream of the pump 42 and connected to the control unit 33 in order to control the flow of sea water flowing through the internal conduit delivery 73 of the measuring cell 41. The central unit 33 thus regularly checks the normal flow rate of the pump 42 fixed at a determined value. Several supply voltages of the pump 42 can be defined and stored in the control unit 33 which chooses one of these voltage values making it possible to maintain the flow rate of the pump at a constant value if a significant drop in the latter appeared during operation. The switching, by the central unit 33, from one supply voltage value of the pump 42 to another is thus controlled by the measurement of the flow rate by this central unit.

 All the information recorded in the central control unit 33 relating to the values supplied by the sensors for measuring the physico-chemical parameters 81-83 and to the seawater pressure temperature values at different depths as well as the flow values , can be transmitted periodically to a coastal station for managing this information. Such transmission can take place over the air.

 The measuring device according to the invention makes it possible to automatically and regularly measure the physico-chemical parameters of seawater autonomously. The modular structure of the blocks of the measuring cell and their interchangeability allows any block to be easily replaced measurement faulty by another, regardless of which floating sampling and measurement site equipped with a measurement cell 41.

 It will be noted that the sampling device thus makes it possible to efficiently route the seawater sampled at different depths to the cell for measuring the physico-chemical parameters of seawater without any human intervention. In addition, the sampling device also makes it possible to perform the function of anchoring the floating body by integrating a mooring cable in the submerged tubular collecting body. At the same time, any interference that may occur between the submerged tubular sample body and surrounding mooring cables is removed when these are separated from the submerged body.

 The use of sheaths for receiving the sampling tubes and the electrical conductors allows the latter to be easily withdrawn from the sheaths from the floating body if necessary, for example to replace them.

 Of course, the device of the invention can be associated with a floating body moored in a different way from that shown in Figures 1 and 2. Thus, the sampling device can fully ensure the anchoring function of the buoy 1 as shown in Figure 3 by integrating the single mooring cable in the submerged tubular body 4 as in the mooring mode of Figures 1 and 2 and by fixing the free end of the cable to an anchor chain 2 fixed to a body dead 3 resting on the seabed. The mooring of the floating body can be carried out by a number of mooring lines other than three as shown in Figures 1 and 2. The most frequent case, at shallow depths, will be the mooring with four lines. In this case, the ballast 5 used in FIG. 1 is not extended by the chain 7 connected to the dead body 3. For larger bottoms, we will opt for the single line mooring explained above where the immersed tubular body is fixed to the buoy with a crow's feet and extended downwards by the anchor chain.

 Furthermore, the sampling device of the invention, instead of being associated with a floating body, can also be associated with a pylon anchored to the seabed or with a port or coastal infrastructure. The device of the invention can also be used to take fresh water, for example from a lake, instead of sea water.

 In addition, it is possible to locally ballast the immersed tubular body by suspending chains from the sleeves shown in FIG. 1. Finally, the immersed tubular body can be provided with sleeves placed outside the sampling openings and intended only to locally provide buoyancy. or ballast with a submerged body.

Claims (15)

 1. Device for measuring physico-chemical parameters of seawater, characterized in that it comprises a certain number of blocks (66) assembled together so as to define two internal suction pipes respectively ( 72) and seawater discharge (73), some of the blocks (66) each comprising an internal radial duct (85) opening into the suction duct (72) and a sensor means (81-83) for a parameter for measuring seawater, such as pH, conductivity, temperature of seawater or the level of oxygen dissolved in it, housed in the radial internal duct (85).  2. Device according to claim 1, characterized in that at least one of the assembled blocks (66) comprises two substantially parallel internal conduits opening into the internal suction conduit (72) and intended to be connected to an external conduit bypassing seawater to an external sensor means for measuring other physicochemical parameters of seawater, such as for example its chlorophyll content or its nitrate or sulphide level.  3. Device according to claim 1 or 2, characterized in that at least one of the assembled blocks (66) comprises two substantially parallel internal conduits opening into the internal discharge conduit (73) and intended to be connected to a conduit external sea water bypass to an external sensor means measuring, for example, the flow of sea water.  4. Device according to one of the preceding claims, characterized in that the block located downstream of the measuring blocks (66) relative to the direction of circulation of the sea water in the internal suction duct (72) comprises two substantially parallel internal conduits (87, 90) opening respectively into the internal suction (72) and discharge (73) conduits and allowing the connection of a hydraulic pump (42) in series in the suction and discharge conduits (72, 73).  5. Device according to one of the preceding claims, characterized in that the aforementioned blocks (66) are fixed to each other in a removable and interchangeable manner by mechanical fixing means.  6. Device according to claim 5, characterized in that each mechanical fixing means from one block (66) to another comprises a lug (68) fixed articulated to a block (66) and foldable manually to lock to a part angle (69) integral with the other block (66).  7. Device according to one of the preceding claims, characterized in that the assembled blocks (66) are mounted on a floating body (1), such as a buoy, moored to the seabed and form part of a hydraulic circuit comprising, in series, a submerged tube (15) for sampling sea water, the internal suction pipe (72), the hydraulic pump (42) mounted on the floating body (1), the internal delivery pipe (73) and a submerged liquid delivery tube (15).  8. Device according to claim 7, characterized in that the blocks (66) are mounted by threading on support rods (67) fixed on the floating body (1).  9. Device according to claim 7 or 8, characterized in that it comprises an immersed tubular body (4) containing several sampling tubes (15) opening respectively into through openings (16) of the wall of the tubular body (4) at different depths and a multi-channel hydraulic distributor (17) on the floating body (1), mounted in the aforementioned hydraulic circuit (39) and controlled by a control center (33) so as to select periodically for determined durations corresponding respectively during seawater sampling phases, a series of different pairs of tubes among the available tubes (15) of the tubular body (4), one of the selected tubes (15) of each pair constituting the sampling tube (15 ) of the hydraulic circuit (39) and the other tube (15) of this pair constituting the discharge tube of the hydraulic circuit (39).  10. Device according to claim 9, characterized in that the control center (33) performs at each abovementioned sampling phase at least one measurement of a physico-chemical parameter supplied by at least one of the associated sensors (8183) to a block (66).  11. Device according to claim 9 or 10, characterized in that the central control unit (33) continuously monitors the flow of water in circulation in the hydraulic circuit (39) from a flow meter associated with one of the assembled blocks (66) and modifies the supply voltage of the suction pump (42) in the event of loss of flow so as to maintain a constant flow of water in the hydraulic circuit (39).  12. Device according to claim 9 or 10, characterized in that the control unit (33) performs a measurement of seawater temperature and pressure at each phase of seawater withdrawal from a means temperature and pressure sensor (23) located at each sampling opening (16) of the immersed tubular body (4).  13. Device according to one of claims 9 to 12, characterized in that the control center (33) stores all the measured values of the physicochemical parameters during several measurement cycles and transmits them periodically, for example by radio, to a coastal management facility.  14. Device according to one of claims 7 to 13, characterized in that it comprises two chlorinating means (40, 43) mounted in series in the hydraulic circuit (39) respectively upstream of the assembled blocks (66) and downstream the suction pump (42); and a hydraulic reversing means (44) between the two chlorinating means (30, 43) and the assembly of assembled blocks (66) - suction pump (42), controlled by the control unit (33) outside the cycles of aforementioned sampling and measurement to clean all parts of the hydraulic circuit (39).  15. Device according to claim 14, characterized in that each chlorinator means (40, 43) is controlled by a direct voltage supplied by the control center (33) so as to produce an optimal chlorine level necessary for the protection of the circuit hydraulic.