BE1021773B1 - AERONTICALLY AUTONOMOUS AERATION TURBINE - Google Patents

Abstract

Aerator (2) generally on a float (4) for aeration of natural or artificial water bodies (5) and water purification lagoons which resemble an energetically autonomous unit, the aerator comprising a motor (1), an aeration unit driven by said motor (1), and a solar energy collection system (3), characterized in that the aerator is a slow type surface aerator, in that the motor is of the type asynchronous, and in that the system further comprises means for transforming the electric current produced by said solar energy collection system (3) into an alternating current (AC) which can be assimilated by said motor (1).

Description

Energy-autonomous ventilation turbine

The present invention relates to electromechanical aeration for biological water treatment. The object of the invention is to use a form of solar energy (wind and light) not directly storable and to allow the transformation of this energy source so that the energy source is storable.

Before developing new surface aerators or aeration turbines, an evaluation of the different aeration systems must be made based on past experiences and existing literature. Aeration systems can be subdivided into 2 groups: background aeration and surface aeration. The bottom aerator can also be subdivided into different systems, the most efficient of which is the system known as "fine bubbles". Surface aerators are subdivided into slow aerators and fast aerators. Slow aerators are further subdivided into vertical shaft aerators and horizontal shaft aerators (brushes).

Slow vertical shaft aerators are the most commonly used because they have the highest oxygenation efficiency, the highest oxygenation capacity per unit and the best mixing or propulsion capability in oxidation ditch units. In addition, these can be easily regulated in speed either by dual-speed motors or by frequency converters.

Compared with fine-bubble aeration systems, slow-type vertical shaft surface aerators have multiple advantages as well. The investment cost is significantly lower. It is the same for maintenance while fine bubble aerators must be cleaned regularly. The service life of slow-type surface aerators is much higher and their reliability much higher. The oxygenation yield appears to be lower initially, but after aging of the membranes, the oxygenation efficiency of the fine bubbles decreases considerably. The transfer of oxygenation to urban wastewater is more favorable to slow surface aerators. This ratio is usually known as the alpha factor. Over long periods it can be seen that the energy consumption of slow-type surface aerators is similar to fine bubbles. Other criteria are also important to consider such as noise, aerosols and accessories essential to a ventilation system. Slow surface aerators can be completely covered to remove any nuisance. Current accelerators, fans, instrumentation, essential for fine bubbles, are not for slow type aerators.

All these considerations lead to the development and production of slow-surface type aerators with vertical or horizontal shafts that have very good energy yields. The invention consists in using the intrinsic properties of these turbines in an autonomous energy application.

All these aeration systems use the asynchronous motor which has excellent mechanical and electrical properties. The invention will therefore if possible to maintain this type of drive motor.

In lagoons, lakes, ponds, the light produced by photosynthesis of oxygen in a natural way. The advantage of this natural process lies in the absence of fossil primary energy consumption and in the absence of air production tools. However, in view of the increase in pollutant load, photosynthesis is not always enough. The designer then uses mechanical aerators that convert electricity into dissolved oxygen.

Surface aerators are regularly used for aeration of lagoons. Thanks to their brewing capacity, they make it possible to increase the depth of the lagoons and to oxygenate the accelerating biological purification process. However, lagoons are regularly installed outside urban centers, in basins and far from any home and electricity grid. This requires electricity that can be supplied either by the grid or by a renewable or fossil independent primary energy production unit. Oxygenation of bacteria is a continuous process and microorganisms can not do without oxygen. The classic solution would be to provide electric batteries to cover periods without renewable energy. The invention avoids this type of expensive and unreliable storage by accumulating dissolved oxygen in a large volume of water. To this end, the invention relates to an aerator as claimed in claim 1, and to a use of such an aerator as claimed in claim 6.

One embodiment of the invention consists of an oxygenation apparatus (2), generally on a float (4), natural or artificial water bodies (5), which gathers on an energy-autonomous unit, the capture system of solar energy (3), the transformation of the electric current produced into an assimilable current by an asynchronous type motor (1) and the short-term storage of the energy in a chemical form (5). The apparatus may consist of different variants listed below:

The means of producing solar energy is either wind or light. The apparatus is composed either of a floating bridge or of certain fixed supports on banks.

The aerator will be a propeller vertical shaft or horizontal low immersed.

The structure (s) or chassis and floats may be in different types of materials, steel, composite and synthetic.

The mobile can be covered to limit nuisance or recover energy losses dissipated.

The number of floats will depend on the size of the aerator and they can be either unsinkable or empty. The device is not intended to be moved but it can move by its own means to increase its energy efficiency.

The control of the device is made either from the bank or on the device itself. The invention is not limited to the embodiments described in this document but also covers the various variants with respect to electrical cables and their implementation, gear reducers, motor efficiency classes, computer calculation programs and the optimization.

Claims (7)

1. Aerator (2) generally on a float (4) for the aeration of natural or artificial water bodies (5) and water purification lagoons which collects on an energy-autonomous unit, the aerator comprising a motor (1 ), an aerator driven by said motor (1), and a solar energy collector (3), characterized in that the aerator is a slow-type surface aerator, in that the motor is of asynchronous type, and in that the system further comprises means for transforming the electric current produced by said solar energy collection system (3) into an alternating current (AC) that can be assimilated by said motor (1). 2. Aerator according to the preceding claim, characterized in that the ventilation device comprises a vertical or horizontal shaft propeller adapted to be slightly immersed. 3. An aerator according to claim 1 or 2, wherein the transforming means comprises an electronic control unit (7) of the motor and converting the DC type electrical energy into pulse of variable width at a fixed frequency. 4. An aerator according to any one of the preceding claims, comprising a software for optimizing energy production according to the available solar energy. ' An aerator according to any one of the preceding claims, comprising a plurality of aeration units on a floating unit. 6. Use of the aerator according to any one of the preceding claims, installed on a body of water, to accumulate a quantity of dissolved oxygen in the water. 7. Use according to claim 5, wherein the aerator is ideally oriented with respect to the direction of a solar energy source.