The present invention relates to a carbon dioxide supply system for water treatment, such as in swimming pools, aquariums and in facilities using water in general, which allows obtaining greater performance, minimizing carbon dioxide consumption and making full use of the carbon dioxide stored in the supply system. Background of the Invention

Carbon dioxide is used as a hydrochloric acid substitute for controlling water pH. With respect to hydrochloric acid, the use of carbon dioxide has the advantages of reducing the formation of harmful substances and eliminating the smell characteristic of said acid.

Carbon dioxide can be supplied to swimming pools from carbon dioxide cylinders or bottles.

Conventional carbon dioxide injection installations comprise a porous-type supply system and a feed installation that usually consists of two groups of bottles, one that is being used and the other serving as a reserve.

In order to mix the gas in the water as efficiently as possible, microbubbles must be formed. This is achieved by passing the carbon dioxide through a porous means with holes.

Furthermore, changing the group of bottles (when one runs out and the full one starts up) is done manually or semi-automatically. With semi-automatic valves, the change is performed upon detecting that the group of bottles does not have suitable pressure. The problem is that gas pressure can vary greatly depending on room temperature and on consumption rate. Therefore, one can never make full use of the entire volume of stored carbon dioxide, since the gas cools down, pressure in the cylinders drops and the valve makes the change ahead of time, an unused volume of gas always remaining inside the bottles.

These two concepts of operation in conventional installations means that a great deal of gas is wasted and gas transfer from equilibrium is limited (pressurized microbubbles which increase in volume in other conditions, limited transfer contact, etc.), resulting in a very expensive and unviable use for economically competing with other systems.

Therefore, an objective of the present invention is to provide a carbon dioxide supply system for water treatment in which the carbon dioxide present in the bottles can be made full use of and carbon dioxide consumption is minimized. Description of the Invention

The carbon dioxide supply system for water treatment of the invention solves the mentioned drawbacks, presenting other advantages that will be described below.

The carbon dioxide supply system for water treatment according to the present invention comprises at least one carbon dioxide tank and is characterized in that it comprises suction means suctioning carbon dioxide from said at least one tank.

According to a preferred embodiment, said suction means are a Venturi tube. Advantageously, the carbon dioxide supply system for water treatment according to the present invention also comprises a reactor, the purpose of this reactor being to control pressure, diffusion and contact time.

According to a preferred embodiment, said reactor internally comprises a plurality of solid particles of a material the density of which is, optionally, less than the density of water.

According to a preferred embodiment, the carbon dioxide supply system according to the present invention also comprises an optional pump placed after said suction means, for example.

Furthermore, the carbon dioxide supply system for water treatment according to the present invention can also comprise a resistance at the outlet of said at least one tank to prevent the carbon dioxide from freezing.

Furthermore, said supply system preferably comprises injection means for injecting a disinfectant upstream of the carbon dioxide injection, which allows increasing pH.

The carbon dioxide supply system for water treatment according to the present invention can also comprise at least one valve located between said at least one tank and said suction means, regulating carbon dioxide consumption and partially neutralizing said disinfectant.

Said set of valves is preferably associated with a flow counter, such as an impulse counter.

Furthermore, the carbon dioxide supply system for water treatment according to the present invention also advantageously comprises a decarbonator which allows eliminating alkaline substances from the water.

Said suction means advantageously comprise a water inlet and a carbon dioxide inlet. In the carbon dioxide supply system for water treatment according to the present invention, the pressure in the area of the suction means is less than the pressure in the area of the reactor, defining a low-pressure area and a high- pressure area, respectively.

As a result of using the suction means, the carbon dioxide in said at least one tank can be made full use of, since the suction means work under atmospheric pressure and suction said carbon dioxide.

Furthermore, carbon dioxide consumption is also lowered to make it more economically competitive than conventional systems and profitable for use.

Furthermore, the combination of the suction means and of the optional pump where carbon dioxide is mixed with water allows working at a lower pressure than usual, creating smaller bubbles and forming more surface area.

To fulfill the two objectives of the present invention (making full use of the carbon dioxide and minimizing consumption), the first concept is to perform carbon dioxide injection by Venturi effect in the suction area of the pressure pump instead of using porous means. This new concept allows working with negative pressure with minimum injection energy (suction area). In order to make the bubble as small as possible and to increase diffusion performance, the injection is performed in the suction area, such that the mixture is forced to pass through the turbine of the pump acting as a large, high-performance agitator.

Brief Description of the Drawings

To better understand the preceding description, a drawing schematically depicting a practical embodiment only by way of non-limiting example is attached.

Figure 1 is a diagram of the components of the carbon dioxide supply system for water treatment according to the present invention.

Description of a Preferred Embodiment

Figure 1 is a diagram of the components of the carbon dioxide supply system for water treatment according to the present invention. It must be indicated that reference will only be made in the present description to elements which are part of the carbon dioxide supply system of the present invention, the rest being conventional components that are not part of the present invention.

The carbon dioxide supply system for water treatment according to the present invention comprises at least one carbon dioxide tank 1 , two in the case of the depicted embodiment. A tank of this type can be a conventional carbon dioxide bottle, for example. It is advisable to use more than one carbon dioxide tank, since it can thus be used continuously even though one of the tanks is completely empty.

Each tank 1 comprises, associated therewith, a respective valve 12 which will open or close as described below.

A resistance 2 providing the heat necessary to prevent the carbon dioxide passing through the corresponding pipe from freezing can be arranged at the outlet of these tanks 1.

Figure 1 also schematically depicts a swimming pool 10 which has a water outlet pipe for water to exit said swimming pool 10. A corresponding disinfectant (pipe 9 injecting the disinfectant) is injected into the water from the swimming pool upstream of the carbon dioxide injection in the water outlet line for water to exit the swimming pool 10.

It must be indicated that the carbon dioxide supply system according to the present invention can be used in any facility with water that requires treatment with carbon dioxide, such as an aquarium, a spa, or the like.

Said carbon dioxide is suctioned by means of suction means, such as a Venturi tube 4, such that the carbon dioxide reaches a recirculation and centrifugation pump 5, together with water from the swimming pool 10, according to the depicted embodiment, because the supply system of the present invention could also work without any pump.

Said Venturi tube 4 suctions the carbon dioxide, working at a pressure below atmospheric pressure.

Small bubbles are produced when mixing water from the swimming pool 10 and carbon dioxide, such that the exchange surface between the water and carbon dioxide is larger than in conventional carbon dioxide injection systems.

There is arranged before the Venturi tube 4 a system of valves (generally indicated by means of reference number 3) for injecting carbon dioxide slowly, at a rate less than conventional hydrochloric acid. This system of valves particularly comprises one or more needle valves or motorized valves. If there are two valves, one is used to regulate carbon dioxide consumption at the desired value and the other one is used to partially neutralize said disinfectant. If a single valve is used, it will be used to regulate carbon dioxide consumption at the desired value and to partially neutralize said disinfectant.

Furthermore, an impulse counter 8 working as a flow counter is also provided, such that when the systems detects the absence of flow, the corresponding valves 12 of said tanks 1 close and open to assure carbon dioxide supply according to the programmed instructions.

The carbon dioxide supply system comprises a reactor 6 after the pump 5 which allows increasing the contact time between the water and carbon dioxide.

In the supply system, pressure in the area of the Venturi tube 4 is lower than the pressure in the area of the reactor 6, defining a low-pressure area and a high- pressure area, respectively.

This reactor 6 is a low-speed area with countercurrent and maximum pressure having solid particles therein provided with star-shaped vanes or vanes with any configuration, for example, breaking the current flow and reducing the speed of water, preferably of a material with a lower density than water, and they are placed randomly.

Once the water has been sufficiently mixed with the carbon dioxide, the treated water is sent back to the swimming pool 10.

According to the depicted embodiment, the carbon dioxide supply system according to the present invention also comprises a decarbonator, eliminating alkaline substances from the water.

Though not described in the present invention, the carbon dioxide supply system according to the present invention also has electronic control means, such as programmable software, associated therewith, assuring the correct operation of the entire system by controlling correct start-up of the system and regulating the injection, for example.

It must also be indicated that said electronic control means also allow controlling more than one carbon dioxide supply system simultaneously for different facilities at the same time.

Although reference has been made to a specific embodiment of the invention, it is obvious for a person skilled in the art that the described carbon dioxide supply system for water treatment is susceptible to a number of variations and modifications, and that all the mentioned details can be replaced with other technically equivalent details, without departing from the scope of protection defined by the attached claims.