DESCRIPTION

"HYPERBARIC SYSTEM FOR THE LONG-TERM STUDY AND CONSERVATION OF INTERMEDIATE- AND DEEP-DEPTH AQUATIC ORGANISMS"

Technical field of the invention

The present invention refers to a hyperbaric device that allows water circulation within a reservoir, at controlled pressures, from a water reservoir to atmospheric pressure, as well as controlling the most relevant physiochemical parameters of the said water.

Summary of the invention

The present invention consists of a complete system that allows the study and preservation of aquatic organisms (for instance of sea organisms) which inhabit deep depths, allowing the simulation of existent high hydraulic pressures as well as the control of the most important water physiochemical parameters for the development of the said organisms.

This system allows accomplishing open circuit water circulation, maintaining the water inside a hyperbaric reservoir at the desired pressure in which the aquatic organisms meant to be studied will be placed, as well controlling the most important physiochemical parameters of the said water.

The present invention is useful, namely, in terms of:

- carrying out a lab study of aquatic organisms lifecycle under high pressures, allowing their survival and convenient observation, the water physical parameters being able to be measured and altered, such as salinity,

pH, GH, KH values, water temperature, oxygen values, etc;

- studying the influence of pressure cycles in aquatic organisms ;

- maintaining deep-sea organisms in good conditions and for long periods of time, allowing their observation by investigators but also, for the public in general.

Background of the Invention

The present invention refers to a hyperbaric system for the study and maintenance of intermediate- deep-sea aquatic organisms, characterized in that it allows the study and the preservation of such organisms, simulating the hydraulic pressure present in their natural habitat and allowing the control of the environmental conditions required to their development. Preferably, this system will be used in lab simulation of deep-sea conditions including hydrothermal sources.

There has been having an increasing interest in the study of the deep-sea biology and in technologies that allow the study of deep-depth organisms and of the effects of the exhibition of those organisms to identical conditions to those found in high hydrostatic pressure environments, in marine or fresh water environments.

The study of depth organisms as well as the study of the effects of high depths and their variations upon aquatic organisms has been accomplished mainly by means of two approaches. A first approach has been the in situ study, with equipments that allow the carrying out those studies in the habitats where those organisms live. Those equipments are fundamentally submergible, either piloted or not, and imply bulky investments, a great logistics

availability that includes mandatory support ships which cannot operate in highly adverse environmental conditions. The second approach consists of using chambers and hyperbaric systems to simulate in a laboratory the depth conditions found and that are realistic and relevant from a biological point of view.

However, most of the existent equipments used to maintain and to study the effects of the conditions found in intermediate/high depths don't allow the automation of the operation procedures thus limiting at once the maintenance of those conditions in short periods of time in hours or days .

Another drawback of many of the existing laboratory hyperbaric systems is the incompatibility of the materials used in its construction with aggressive fluids such as sea water.

Still another limitation refers to the reduced volume of the containment structure of the organisms under pressure, which in most of the existing laboratory pressurization systems present reduced volumes, from some hundreds of cubic milliliters to about a dozen of liters, which obviously limits its use to the study of organisms with corresponding dimensions.

So being, and taking these limitations of the previous systems into account and in order to overcome them, a system allowing an automated simulation of the deep-depth conditions including cyclic variations of hydraulic pressure was developed, which operates for long periods of time, which can be used even with aggressive fluids (such as salt-enriched see water, etc.), comprising high

volumetric capacity, high water renewal rate and the ability to control the physicochemical conditions of said water. An hyperbaric system with the features of the present system should be understood as being useful to investigation institutions, universities, oceanarium and another associations that are devoted to the study, exhibition and maintenance of intermediate-/deep-depth organisms .

General description of the invention

The present invention refers to a system allowing the study and the preservation of aquatic organisms (fresh, salty water inter alia) that inhabit deep depths, simulating the respective hydraulic pressures and allowing the control of the necessary environmental conditions to the development of the said organisms.

This system makes it possible to lab simulation of the conditions of a certain aquatic ecosystem, during the whole lifecycle of the organisms meant to be studied or preserved.

The developed system is mainly composed of:

- a pressure reservoir made of materials capable of ensuring long operation periods not requiring maintenance operations, comprising windows that allow visual observation and illumination of its interior;

- a tank maintained at atmospheric pressure, which feeds the water flow that runs in the pressure reservoir, and which contains a complete water treatment system required to maintain the quality thereof, mainly consisting of a series of filters (mechanical, biological, of activated charcoal among others), as well

as of a water temperature regulation unit. Instead of the tank, the ocean itself or any fresh water flow or any other water source can be used as water deposit for the system. Should the tank capacity be substantial, the use of the water temperature regulation unit will no longer be required for its cooling;

- a pressure reservoir pressurization system, mainly composed of a hydraulic pump actuated by electromotor, a pressure-reducing control valve, at least a pressure transducer, a pressure controller that should have the possibility to send and receive data to and from a personal computer which is provided with a data receiving board and appropriate software. If one wishes to maintain the hydraulic pressure at a constant value, this system allows using a simpler controller, strictly of manual regulation, thus avoiding the use of the computer system;

- conventional security system in hydraulic application of intermediate/high pressures comprising in particular safety pressure-limiting valves.

- The system object of this patent allows the open circuit water circulation maintaining it at the desired pressure inside a reservoir where the organisms meant to be studied or preserved are placed.

Description of the Drawings

Figure 1: Schematic representation of the pressurization (or hyperbaric) system developed. In this diagram (1) represents the hyperbaric reservoir where the organisms meant to be studied and preserved are placed, (2) represents a tank with water comprising no pressure, which feeds the water flow which runs inside the hyperbaric reservoir, (3) represents a mechanical water filter, (4)

represents a biological filter, (5) represents an activated charcoal filter, (6) represents a water temperature regulation unit, (7) represents a flow rate-variable hydraulic valve actuated by electromotor, (8) represents an electromotor for actuating the hydraulic pump, capable of operating at different rotational speeds, (9) represents an pressure-reducing hydraulic valve with proportional control, (10) represents a pressure transducer (or sensor), (11) represents a pressure control with electrical signal outlets which allow an easy connection to a data receiving card (12), connected to a personal computer (13); (14) represents a filter (or shut-off valve) with manual actuation, (15) represents an electropneumatic converter and (16) represents an under-pressure air collector.

Figure 2: Schematic representation of the security against overpressure on the hyperbaric chamber. This diagram (17) represents a pressostat, (18) a hydraulic valve which in case of overpressure carries out the water 'by-pass' from the hyperbaric reservoir (1) to the tank (2) and (19) a hydraulic valve which limits security pressure.

Detailed description of the invention

The present pressurization (or hyperbaric) system for the study and conservation of aquatic organisms is composed of two main tanks: the hyperbaric tank (1) where the organisms meant to be studied or maintained are placed and a tank (2) that acts as water reservoir, at atmospheric pressure .

The hyperbaric tank (1) might have a cylindrical design with spherical or torospherical ground and it will have at least a hatchway to allow the placement/collection of the

aquatic organisms meant to be studied. It will also have at least an observation window (that can be namely made of with glass, polycarbonate or acrylic) that will further allow the illumination of the reservoir' s interior by an external light source. The light source should allow brightness rate control inside the reservoir. This reservoir should be made resistant against corrosion resulting from the fluid that runs under pressure in its interior and safely resist to the maximum hydraulic pressure of specified use. If the present system is used 'for the study of sea organisms, and sea water having a particularly aggressive chemical composition, stainless steel can be used in the construction of the reservoir, the fiberglass- reinforced plastic (PRFV), aramid fiber- reinforced plastic (PRFA), carbon fiber-reinforced plastic (PRFC) or hybrid solutions with metallic and structural covering in PRFV/PRFA/PRFC. The covering, that will constitute the interior of the pressure reservoir, might further be covered by a polymer with good resilient properties against corrosion (for instance, but not limited to halar or the polytetrafluorethylene, or PTFE) . It will also have some openings that will easily allow connecting pressure transducers (10) and measuring relevant water physiochemical parameters. At least a filter (or shut-off valve, manually drivable) (14) must also be provided to allow air bleeding of the pressure reservoir during water filling if necessary for the feeding of the aquatic organisms .

The water flow required to guarantee the good quality of the same inside of the hyperbaric reservoir takes place letting the water of a tank (2) in the hyperbaric reservoir under pressure and to exiting therefrom back to the tank at atmospheric pressure. After passing the proportional valve

(9), the water (at atmospheric pressure) which exits the reservoir can go through a water treatment system that will namely contain a series of mechanical (3), biological (4) and activated charcoal (5) filters. If the capacity of this reservoir is sufficiently high, it will be possible to operate this system by guarantying the good water quality flowing inside the hyperbaric chamber without the aid of any water treatment system (for instance, in the case of salt water, water circulation can be done from the sea itself) . This water treatment circuit is independent from the hyperbaric chamber pressurization circuit and it further allows water treatment using a system that filters water from the tank.

To maintain the temperature of the water inside the tank at a certain desired value, one might need the aid of a water temperature regulation system of the temperature of the water (6), that it will avoid progressive water heating, mainly if small capacity tanks are being used.

In the presently described system, the water is pumped from the reservoir into the hyperbaric chamber by means of a flow rate-variable hydraulic pump (7), capable to ensure the maximum hydraulic pressure desired. As pump protection system, when the maximum hydraulic pressure is achieved, the hydraulic pump should be provided with a system allowing water "by-pass", from its output into the tank. The pump actuation is carried out by an electromotor (8) with speed control to which a reducer might be associated, if required. By means of rotational speed variation of the engine it will be possible to obtain different values for the water flow rate that will run in the hyperbaric chamber. This water flow rate should have an enough value to ensure that the mixture of water which was treated inside the tank with the water inside the hyperbaric

chamber leads to the maintenance of the desired environment inside of the test hyperbaric chamber. The water output from the reservoir under pressure is made through the proportional valve (9) the opening regulation being achieved automatically by an electrical signal from of programmable pressure controller (11), with ^λ PID' ( 'proportional/integral/derivative' control) . For high hydraulic pressure values, the valve opening (9) actuation can be done with the aid of pneumatic actuators fed from a compressed air collector (16). In this case, the electrical signal from the pressure controller is not used to directly control the proportional hydraulic valve but rather to control the pneumatic actuator, by means of using an electro-pneumatic converter (15). This converter exchanges the controller electrical signal into a pneumatic signal that the pneumatic actuator will use for controlling the hydraulic valve. The pressure measurement inside the hyperbaric chamber is obtained by a pressure sensor (10) whose output electrical signal should be conveniently connected to the associated pressure controller inlet. The programmer compares in real time the value of the pressure inside the hyperbaric chamber, being red by the pressure sensor with the pressure programmed value, adjusting the open/close of the proportional valve in order to minimize the differential of these two values.

The use of a data receiving card (12) connected to the pressure controller allows, by means of an appropriate communication protocol, the bidireccional communication between this controller and a personal computer (13). This computer should be provided with the appropriate software which allows an easy collection and register of pressure values in the hyperbaric chamber as well as an easy programming of the pressure controller.

The security of the system against overpressure should be achieved by means of the constant use of a pressure- limiting security valve (19). Another safety device that will act before the security valve (19) will be composed of a pressostat (17), conveniently regulated to act if the hydrostatic pressure inside the chamber reaches a value close to the maximum pressure value allowed, whose electrical signal must be used to pilot a two-way hydraulic valve (18) which in this case will carry out the 'by pass' of the water from the reservoir to the tank without pressure.

a flow detection valve can be added to the system, being assembled for instance to the pump output and which, by detecting a water flow rate interruption, should allow the proportional valve (9) to close and thus maintain the pressure inside the hyperbaric chamber even if the power supply is stopped. If reservoir has a sufficient capacity, it will be possible to maintain the organisms under pressure and in good conditions during some time.

The use of back-up systems allows the normal operation of the same system when the power supply is interrupted by the network.

Implementation Examples

A prototype of the system has already been built, comprising the hyperbaric chamber, built in stainless steel, and which allowed the study of sea organisms (adult flounders, Platichthys flesus Linneeus, 1758) under hydrostatic pressure-controlled conditions, for 15 days. Operation procedures were studied with constant hydrostatic

pressures as well as pressure cycles. The maximum hydrostatic pressure value allowed by this system to is of 8 bar (0,8 MPa) .

By the end of the tests it has been concluded that the system worked autonomously and according to plan, without any user involvement. The constructive details and obtained results of the present system can be consulted in as much as :

It must be made clear that the hyperbaric system described previously is mainly a possible implementation example, merely established for a clear understanding of the principles of the invention. Variations and modifications to the previously described embodiment might be carried out, without substantially straying from the scope of the invention. All these modifications and variations should be included in the scope of the present invention and be protected by the following claims.