Device for measuring the physicochemical properties of a liquid contained in a collection tank

Abstract

A device 1 for measuring the physicochemical properties of a liquid contained in a collection tank 2, comprising a float 3 adapted to float on the surface of the liquid contained in the tank 2 and equipped with at least one sensor 4, a base 5 having a receptacle 51 adapted to hold liquid, a guide system 6 connecting the float 3 to the base 5, the float 3 being slidably mounted on the guide system 6 and the guide system 6 being arranged to guide the sensor 4 in the receptacle 51, and a wireless communication unit. Figure to be published with the abbreviation: Fig. 1

Description

Title of the invention: Device for measuring the physicochemical properties of a liquid contained in a collection tank

[0001] The invention relates to the technical field of devices for measuring the physicochemical properties of a liquid in a collection tank, more particularly devices for measuring the pH, electrical conductivity, oxidation-reduction ratio, O2, and ammonia of a liquid, especially urine. Similarly, the invention relates to a collection tank for a liquid, more particularly urine.

[0002] Urine is considered waste that must be disposed of. Its current method of disposal, primarily via the sewer system, is problematic for wastewater treatment plants and more generally raises concerns about the sustainable management of water resources. The nitrogen and micropollutant content of urine does indeed cause problems related to algae growth and the feminization of fish.

[0003] Human urine is known to have proven fertilizing potential in agriculture, just like animal urine, which is already used by farmers. Indeed, urine is rich in nitrogen (N), phosphorus (P), and potassium (K), which are essential elements for fertilizing soils and crops.

[0004] In this context, it was conceived to collect human urine from a building open to the public by installing a tank within the building, connected to the urinals by a piping system. The urine can thus be collected regularly and transported to an industrial processing plant where it can be transformed.

[0005] However, urine is not stable when collected, rapidly losing its nitrogen, phosphorus, and potassium content, rendering it unsuitable for industrial use. This degradation is triggered, in particular, by the hydrolysis of urea into ammonia, a reaction also known as "urease".

[0006] Thus, there is a need to collect the urine before this hydrolysis of urea occurs in order to preserve the initial composition of the urine and therefore to be able to use it as a fertilizer suitable for agricultural use.

[0007] For these purposes, it was conceived to measure the physico-chemical values ​​of the urine in the tank, and in particular the pH or the electro-conductivity of the urine, in order to monitor remotely that the collection of urine in a tank is proceeding satisfactorily.

[0008] Prior art devices for measuring a liquid contained in a tank are known. However, these measuring devices are not suitable for measuring the physicochemical properties of urine contained in a collection tank.

[0009] Indeed, for a reliable measurement, the device's probe must be constantly immersed in the liquid, regardless of its fill level, to prevent it from drying out. However, in this context, the tank must be emptied periodically to collect the urine, which poses a compatibility problem with existing measuring devices.

[0010] Similarly, and in order to obtain a measurement of the homogeneity of the physico-chemical characteristics, the measurement must be carried out near the surface of the liquid to be measured, regardless of the filling level of the tank.

[0011] Finally, the measuring device must be adapted to a collection tank, namely a tank whose volume of liquid inside is variable over time, among other things, it must not interfere with the collection of the liquid, and it must be accessible and easy to maintain.

[0012] The invention therefore falls within this context and seeks to meet all the aforementioned needs while resolving all the aforementioned drawbacks.

[0013] Thus, the invention seeks to propose a device for measuring the physicochemical properties of a liquid, in particular urine, adapted to a collection tank in which the measurement of the physicochemical properties is carried out on the upper surface of the liquid, in particular the pH which may be heterogeneous in the liquid, using an existing sensor, and which is reliable, easy to maintain but also inexpensive. Presentation of the invention

[0014] The invention relates to a device for measuring the physico-chemical properties of a liquid adapted to a collection tank, i.e. which is required to be emptied regularly, reliable and inexpensive.

[0015] For this purpose, a device for measuring the physico-chemical properties of a liquid contained in a collection tank has been developed according to the invention, comprising a float capable of floating on the surface of a liquid contained in the tank and equipped with at least one sensor, a base comprising a receptacle capable of containing liquid, a guidance system connecting the float to the base, the float being mounted to slide on the guidance system, the guidance system being arranged to guide the sensor in the receptacle and a wireless communication unit.

[0016] It is understood that, according to the invention, the base receptacle constantly contains liquid, regardless of the fill level of the collection tank. In particular, during collection, the liquid level in the tank drops until it falls below the level of the receptacle. The tank can then be emptied completely, with the remaining liquid contained in the receptacle.

[0017] In the invention, the sensor, particularly the pH sensor, is mounted on a float so that it follows the variations in the liquid level in the tank. When the liquid level in the tank drops, the float and the sensor descend into the tank. The guidance system then brings the sensor, for example the pH sensor, into the receptacle, whereby the sensor is immersed in the liquid contained in this receptacle as the tank empties. Thanks to the invention, it is therefore ensured that the sensor probe remains constantly immersed in liquid, regardless of the tank's fill level, which allows the use of existing sensors.

[0018] Furthermore, the fact that the measuring device includes a float equipped with a sensor makes it possible to perform an efficient and homogeneous measurement of the physicochemical properties of a liquid. The float ensures that the sensor probe remains constantly on the surface of the liquid.

[0019] Finally, the simple design of the measuring device helps to limit its cost without hindering the collection of the liquid. Indeed, the float adjusts to the level of the liquid contained in the collection tank.

[0020] Preferably, the liquid in the collection tank is animal and / or human urine, preferably human urine.

[0021] The wireless communication unit may be capable of transmitting data acquired by the sensor to a remote communication unit, which makes it possible to remotely monitor and track the progress of a liquid collection, for example urine in a collection tank.

[0022] In a particular embodiment, the sensor includes the wireless communication unit, in particular according to a LoRA protocol, or any other means of remote communication such as LoRaWan, SigFox, 2G, 3G, GPRS.

[0023] Thus, such a sensor allows for the real-time measurement of a physicochemical property of a liquid, enabling continuous monitoring of said physicochemical property to determine the most opportune moment for collecting the liquid in the collection tank. In particular, when the liquid is urine, this characteristic allows for triggering urine collection before the urease reaction begins in the collection tank. It is understood, therefore, that the triggering of urine collection is achieved through data transmissions via the wireless communication unit.

[0024] In a particular embodiment, the base of the measuring device is intended to rest on the bottom of the collection tank. For example, the base may be connected only to the float of the measuring device. In other words, the base is held by the float when the fill level of the tank is sufficient and comes to rest on the bottom of the tank when the fill level of the tank drops.

[0025] In another embodiment, the base of the measuring device is fixed to the bottom of the tank or to the float of the measuring device. In this example, the base and the float can be independent parts. The base therefore remains permanently at the bottom of the tank, and the guiding system ensures that the sensor is immersed in the receptacle when the tank's fill level drops.

[0026] In a preferred embodiment, the float includes a flotation tank, and the sensor includes a measuring head arranged so as to be positioned substantially below a lower surface of the flotation tank.

[0027] Thus, the sensor is always immersed in the liquid being measured so as not to damage the sensor, particularly when the latter has an electrode that must be kept in the medium being measured to prevent its deterioration. Indeed, most sensors, especially pH sensors, cannot remain in a dry environment for more than 30 minutes, otherwise the sensor's measurement reliability will decrease, or the sensor will be completely unable to perform its function.

[0028] The term "lower surface of the flotation tank" means the surface of the flotation tank oriented towards the bottom of the collection tank or the surface in contact with the liquid of the collection tank.

[0029] In a preferred embodiment, the flotation tank has the shape of a disk of revolution.

[0030] Advantageously, the flotation tank has a central opening in which the sensor is mounted. For example, the float may include sensor mounting elements extending into said central opening. If necessary, the guidance system may pass through said central opening, with float guidance elements cooperating with this guidance system arranged within this central opening, in particular arranged on an internal surface of the flotation tank delimiting said central opening, between the sensor mounting elements.

[0031] In another embodiment of the invention, the float comprises a plurality of flotation tanks arranged around a body, each being connected to the body by a branch.

[0032] Preferably, the guidance system comprises at least one rod fixed, via a first end of the rod, to the base, and the float having a guiding element adapted to slide on said rod. Said rod may, in particular, extend in a vertical direction. The base and the float can thus slide relative to each other as the liquid level in the collection tank varies.

[0033] In a particular embodiment, each float guide element has a groove through which the rod is intended to slide. For example, said groove may be formed on an internal surface of the flotation tank, defining a central opening.

[0034] Preferably, the rod includes, at a second end of the rod opposite the first end, a movement limiting element against which the float is intended to come to a stop, in particular as the level of the liquid in the tank increases.

[0035] Thus, when the level of the liquid in the collection tank increases, the float separates from the base, allowing the sensor to continuously measure the physico-chemical properties, such as the pH at the surface of the liquid, and also allowing the base to rise in the liquid to a defined height between the first and second ends of the stem.

[0036] In a particular embodiment, the rod includes a chamfered element arranged substantially at the first end of the rod, and the float includes at least one area complementary to the chamfered element against which said complementary area is intended to come to rest, in particular as the level of the liquid in the tank decreases.

[0037] Preferably, the complementary area to the chamfered element of the float is arranged on the lower surface of the flotation tank.

[0038] Thus, the presence of a chamfered element and an additional area on the float makes it possible to reduce wear on the float and the rod during repeated contacts between these parts, particularly during the collection of liquid in the collection tank.

[0039] In a preferred embodiment, the chamfered element of the stem is connected to the base by a plate extending over a height greater than the height between the complementary area and the lower surface of the flotation tank.

[0040] In another embodiment, the guidance system includes at least one rail and the float includes a guide element in the form of a slide in which the rail is housed.

[0041] In a particular embodiment, the base comprises at least two feet arranged around the periphery of the receptacle and each extending over a height greater than or equal to that of the receptacle.

[0042] Thus, the base can stabilize on the bottom of the collection tank when the latter empties of the liquid.

[0043] The invention also relates to a collection tank comprising the measuring device according to the invention.

[0044] In a particular embodiment, the collection tank comprises a rail fixed to the bottom of the tank and connected to the float of the measuring device, said rail having a The height must be at least significantly greater than the height of the float and base assembly. Preferably, the rail is arranged along the entire height of the tank.

[0045] In a particular embodiment, the base of the device is a recess in the bottom of the tank.

[0046] Other advantages and features of the present invention are now described by means of purely illustrative and in no way limiting examples of the scope of the invention, and from the accompanying drawings, in which the various figures represent:

[0047] [Fig-1] is a schematic representation of a perspective view of the measuring device according to the invention, when the tank is filled with liquid.

[0048] [Fig.2] is a schematic representation of a perspective view of the device measurement, when the tank is empty.

[0049] [Fig.3] is a schematic representation of a perspective view of the device measure according to another embodiment.

[0050] [Fig.4] is a schematic representation of a perspective view of another mode of the implementation of the measuring device.

[0051] For reasons of simplicity and clarity of illustration, the elements shown in the figures have not necessarily been drawn to scale. Thus, the dimensions and relative proportions of certain elements may be exaggerated or reduced.

[0052] In the following description, identical elements, by structure or by function, appearing on different figures retain, unless otherwise specified, the same references.

[0053] It should be noted that in these figures the structural and / or functional elements common to the different variants may have the same references.

[0054] Of course, various other modifications can be made to the invention within the scope of the annexed claims.

[0055] With reference to [Fig. 1] to [Fig. 4], the invention relates to a measuring device 1 for a physicochemical property, preferably the pH of a liquid contained in a collection tank 2. In the example illustrated in [Fig. 1] and [Fig. 2], the measuring device is intended to be installed in a urine collection tank. [Fig. 1] thus represents the measuring device in a configuration it assumes when the urine level in the tank is sufficient for the entire measuring device 1 to float. [Fig. 2], on the other hand, represents the measuring device in another configuration it assumes when the tank is empty or when the urine level in the tank is insufficient for the entire measuring device 1 to float, at least part of the device 1 then resting on the bottom of the tank.

[0056] As illustrated, the measuring device 1 comprises a float 3 capable of floating on the surface of a liquid contained in the collection tank 2. The float 3 is equipped with a sensor 4, and also a wireless communication unit (not shown) in order to transmit in real time the measurements of the physico-chemical properties of the liquid to coordinate the liquid collection operations.

[0057] The float 3 of the measuring device 1 includes a flotation reservoir 31 in the form of a disc of revolution, which allows the measuring device 1 to follow and remain on the surface of the liquid in the collection tank 2, when the level of the liquid varies.

[0058] The measuring sensor 4 is arranged in a central opening 312 of the flotation tank 31. More specifically, in the described example, the float 3 has a fixing ring in which the sensor 4 is mounted. The fixing ring extends into the central opening 312 by being connected to an inner wall of the flotation tank 31 defining this central opening.

[0059] The sensor 4 includes a measuring head, or probe, 41, the sensor 4 being mounted in the float fixing ring 3 so that the head 41 is positioned substantially below a lower surface 311 of the flotation tank 31.

[0060] Furthermore, the measuring device 1 comprises a base 5 consisting of a receptacle 51 suitable for holding liquid. Said base 5 also comprises at least two feet 52 arranged around the periphery of the receptacle 51 and each extending over a height greater than or equal to that of the receptacle 51.

[0061] In order to monitor the liquid level without hindering the collection of liquid from the tank 2, the measuring device 1 includes a guidance system 6 connecting the float 3 to the base 5. The assembly thus forms a device capable of floating in the urine contained in the tank when the tank's fill level is sufficient.

[0062] The float 3 is mounted to slide on the guide system 6. The guide system 6 thus allows the sensor 4 to be guided in the receptacle 51 and to obtain a uniform measurement of the value of the measured physico-chemical property, such as pH, regardless of the filling level of the tank 2.

[0063] For this purpose, the guide system 6 of the measuring device 1 comprises four rods 61 fixed, by their first ends 611, to the base 5. Each rod 61 passes through a guide element 32 formed on the float 3. In the example described, each guide element 32 is formed by a groove formed in the inner wall of the flotation tank 31 defining the central opening 312. Therefore, the float 3 can slide vertically on the guide system 6 to move away from or towards the base 5.

[0064] The four rods 61 each include on their second end 612, a movement limiting element 613 against which the float 3 is intended to come to a stop.

[0065] As illustrated in [Fig. 1], it is thus understood that when the urine level in the tank 2 is sufficient, the float 3 floats on the surface of the urine. The denser base 5 is held away from the float 3 while being retained by the elements 613 against which the float abuts. The probe 41 is held by the float 5 at the level of the liquid surface, the measurement thus always being taken at the surface.

[0066] When the tank is emptied, particularly to collect the urine, the entire device 1 follows the liquid level. When the base 5 reaches the bottom of the tank, the float 3 continues to descend, guided by the guidance system 6, so that the probe 41 enters the receptacle 51, until it comes to rest against the base 5. The receptacle 51 remains filled with urine throughout the emptying operation, even when the tank is empty.

[0067] We therefore ensure that the probe 41 remains immersed in urine, regardless of the level of filling of the tank, and thus we avoid damaging the sensor 4 when the tank 2 empties.

[0068] In order to limit wear on the rods 61 and the float 3, particularly during variations in the level of the liquid in the tank 2, the four rods 61 each include a chamfered element 614 arranged substantially at the first end 611 of the rod 61. The float 3 includes, at the level of its inner wall, a complementary area 33 to the chamfered element 614 against which said complementary area 33 is intended to come abut.

[0069] In addition, the chamfered elements 614 of the rods 61 are each connected to the base 5 by a plate extending over a height greater than the height between the complementary zone 33 and the lower surface 311 of the flotation tank 31 so as to leave a space between the float 3 and the base 5.

[0070] Another embodiment of the measuring device 1 is shown in [Fig.3].

[0071] The various elements of the device in [Fig.3] are substantially identical to those of the device in [Fig.1] and [Fig.2] except for the float 3.

[0072] In this embodiment, the float 3 comprises a plurality of flotation reservoirs arranged around the periphery of a float body, on which the sensor 4 is mounted. Each reservoir is connected to the body by a branch.

[0073] Another embodiment of the measuring device 1, arranged in a collection tank 2 equipped with a urine circulation circuit to the collection tank 2 and a collection circuit for the collected urine, is shown in [Fig.4].

[0074] In this embodiment, the guiding system 6 comprises a rail fixed to the bottom of the tank 2 and extending vertically over a height of at least substantially greater than the height of the float assembly 3 and base 5. In the example described, the rail 6 extends over the entire height of the tank 2, from the bottom to the upper wall of the tank.

[0075] The device 1 includes a float 3, the function of which is identical to that of the floats in the devices of the preceding embodiments. The float 3 includes a guiding means 32, in the form of a slide housing the rail 6.

[0076] The float 3 is therefore able to slide on the rail 6, as the level of the liquid in the tank 2 varies, in order to keep the sensor probe immersed at the level of the liquid surface.

[0077] The base 5 of the device is formed by an area of ​​the bottom of the tank in which a recess 21 is provided, forming the receptacle.

[0078] The receptacle 21 is therefore intended to receive the head 41 of the sensor 4 when the tank 2 of collection is empty. For this purpose, rail 6 is provided in tank 2 so that float 3 descends towards this recess 21 as tank 2 empties.

[0079] In any event, the invention cannot be limited to the embodiments specifically described in this document, and extends in particular to all equivalent means and to any technically operative combination of these means.

Claims

Demands

1. A device for measuring the physico-chemical properties of a liquid contained in a collection tank 2, comprising: - A float 3 capable of floating on the surface of a liquid contained in the tank 2 and equipped with at least one sensor 4; - A base 5 having a receptacle 51 capable of containing liquid 1; - A guide system 6 connecting the float 3 to the base 5, the float 3 being mounted to slide on the guide system 6, the guide system 6 being arranged to guide the sensor 4 in the receptacle 51; and - A wireless communication unit.

2. Measuring device 1 according to claim 1, characterized in that the float 3 comprises a flotation tank 31, and in that the sensor 4 comprises a measuring head 41 arranged so as to be positioned substantially below a lower surface 311 of the flotation tank 31.

3. Measuring device 1 according to claim 2, characterized in that the flotation tank 31 has the shape of a disk of revolution.

4. Measuring device 1 according to any one of claims 2 or 3, characterized in that the flotation tank 31 has a central opening 312 in which the sensor 4 is mounted.

5. Measuring device 1 according to any one of the preceding claims, characterized in that the guide system 6 comprises at least one rod 61 fixed, via a first end 611 of the rod, to the base 5 and in that the float 3 comprises a guide element 32 capable of sliding on said rod 61.

6. Measuring device 1 according to the preceding claim, characterized in that the rod 61 comprises, at a second end 612 of the rod opposite the first end 611, a movement limiting element 613 against which the float 3 is intended to come to a stop.

7. Measuring device 1 according to claim 5 or 6, characterized in that the rod 61 comprises a chamfered element 614 arranged substantially at the first end 611 of the rod 61, and in that the float 3 comprises at least one area complementary 33 to the chamfered element 614 against which said complementary zone 33 is intended to come to abut.

8. Measuring device 1 according to the preceding claim, characterized in that the chamfered element 614 of the rod 61 is connected to the base 5 by a plate extending over a height greater than the height between the complementary zone 33 and the lower surface 311 of the flotation tank 31.

9. Measuring device 1 according to any one of the preceding claims, characterized in that the base 5 comprises at least two feet 52 arranged around the periphery of the receptacle 51 and each extending over a height greater than or equal to that of the receptacle 51.

10. Collection tank 2 comprising measuring device 1 according to any one of claims 1 to 9.

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