Technological Area:

This invention is related to Coanda type water intake structures which are classified under bottom type water intake structures and most preferred in the area of hydraulic structures, drinking water, domestic usage, and hydroelectric power plants for energy production.

State of the Art:

Coanda type water intake structures are frequently preferred in the field of hydraulic structures, drinking water supply, and treatment process and energy production stages in the hydroelectric power plants.

In the literature, there are some studies related to Coanda type water intake structures (Hazar et al. 2022; Hazar and Elgi, 2021; May, 2015; Huber, 2005; Wahl, 2001). Coanda intakes were tested under various flow conditions using different screen design parameters for both clear water flow and sediment-laden flow conditions. In these studies, mostly, water withdrawal performance and sediment exclusion performance of intake structures have been tested under different discharge conditions with various sediment concentrations and screen design parameters such as different slot widths, screen curvature radius, screen slope, and other design properties.

In a study conducted by May (2015), the sediment concentration data measured in the river and the experimental setup created in the laboratory were used to analyze the water withdrawal and sediment exclusion performances of the Coanda intakes with different screen sloth widths. According to the results, the sediment exclusion performance increases as the slot width of the screen decreases. However, decreasing the slot width causes screen clogging and causes a reduction in the water withdrawal capacity.

Huber (2005) investigated the clogging of Coanda screens as a result of sedimentation to investigate the problems experienced in small hydroelectric power plants. In this study, three different screen slot widths were tested under different flow conditions and sediment feeding methods. This study showed that as the screen slot width decreases, the sediment removal performance increases, but the probability of clogging the screen also increases. This situation causes losses in water withdrawal performance. The study of Wahl (2001) is another important study related to Coanda intakes which investigates the effects of screen design parameters such as wire tilt angle, screen slope, screen curvature radius, and other screen parameters on the water withdrawal capacity.

One of the most recent studies on Coanda type water intakes is the study published by Hazar and Elgi (2021), which experimentally observed the effects of screen curvature radius, screen slope, screen void ratio, and flow conditions on the water withdrawal performance and sediment exclusion performance. As a result of the study, it was observed that the increase in the distance between the screen wires, which means an increase in the void ratio, is quite effective on the water withdrawal performance. Hazar and Elgi (2021), designed Coanda intakes according to the different radius of curvatures and observed that sediment exclusion performance decreases as the screen wire opening increases. When the incoming flow rate is low, sediment exclusion performance also decreases. In contrast, both sediment exclusion and water withdrawal performances increase as the flow rate increases. As a result of the study, dimensionless parameters were obtained using experimental data, and equations were proposed for both water withdrawal and sediment exclusion performances using the multiple linear regression method. This study was further improved by Hazar et al. (2022), where the researchers utilized artificial intelligence methods instead of multi linear regression as previously published in Hazar and Elgi (2021).

In the literature, no studies similar to the invention subject could be found. When the previous studies on the Coanda intakes were examined, it was observed that these studies were related to classical Coanda intakes. During these studies, water withdrawal performance and sediment exclusion performance were investigated.

Although drum and disk filters do not have direct similarity with the invention, they are comparable systems only in terms of being able to rotate and move. However, drum and disk filters have constant slot width and they do not have any feature for selecting the correct screen with respect to the sediment concentration and size. Available drum/disk filters constantly rotate without being subjected to a decision-making process. Advanced versions of these drum/disk filters are produced by companies such as HUBER Company. Differences between this invention and the drum/disk filters are given in more detail in the next section.

Studies in the literature have shown that the increase in the void ratio causes increments in the water capturing performance. The increase in the sediment concentration being transported by the incoming water is the most important factor causing the clogging of the screen. However, there is a decrement in the amount of sediment concentration that is transported in the stream flow, especially in the dry season. In such cases, it is important to use Coanda intakes with screens that have greater bar spacing and void ratio to be able to withdraw the maximum flow rate possible to meet the design flow rate criteria. On the other hand, changing of the appropriate screens does not take place automatically when a conventional Coanda intake is used. Periodically dismantling these structures and replacing them with screens with different void ratios is extremely costly and laborious. Even if the screen change operation is done manually, it is necessary to intervene in the system manually again to optimize the operation when there is an increase in the sediment concentration due to sudden flow increase. The increase in the sediment concentration, which may occur with the sudden precipitation which is a result of climate change, may cause damage to the electronic devices and turbines used in energy production stages. This will cause both economic and energy losses.

Drums and similar screen type structures, which have a rotating screen structure, have fixed slot widths. Since the screen slot widths do not change depending on the change in sediment concentration, it can either be clogged by the sediment or transfer the sediment particles into the withdrawn clear water. Additionally, due to these types of structures constantly rotating, they consume too much energy. Since these types of structures are mostly used in wastewater treatment plants, they are not suitable for installation on streams due to their capacity and working principles.

In the Canadian patent document number CA3082768 (A1) encountered in the literature search, a water intake system integrated into a hydro-power plant is mentioned. Coanda type intake is used in this intake system. The innovations made on the aforementioned screen are related to the spacing and structure of its slot, and as mentioned in our invention, a rotating intake structure that can be changed according to the turbidity value of the water has not been encountered.

In the US patent document number US2020400113A1 encountered in the literature search, the design of the Coanda-effect installation used in a dam structure is mentioned. There is no study and attempt to determine the turbidity of the water on the aforementioned intake screen and change the intake screen accordingly by rotating them.

As a result, a new and novel Coanda type water intake structure design is needed, where its current disadvantages are eliminated and the current state of the art is exceeded.

Short Description of the Presented Invention:

The invention is about a Coanda type water intake structure, in which the existing disadvantages are eliminated, and Coanda screens with different void ratios can be selected through an autonomous decision process with respect to the sediment concentration of the incoming flow. The invention aims to develop an autonomous Coanda type water intake structure that measures the sediment concentration of the incoming water and decides on the most suitable Coanda screen mounted for the measured amount via the motor-controlled rotary intake system with a computer code specifically written for this purpose.

Another aim of the invention is to develop an autonomous Coanda type water intake structure that selects different types of Coanda screens according to the turbidity value of the water.

Another aim of the invention is to develop an autonomous Coanda type water intake structure having minimum energy losses and maximum efficiency for the maximum water withdrawal.

To achieve all the objectives mentioned above and which will emerge from the detailed description below, the present invention relates to the design of a water intake structure containing Coanda intakes, which is one of the frequently preferred bottom water intake structures in the field of hydraulic and water structures, suitable for hydroelectric power plants, and in drinking water withdrawal and treatment systems. The most important feature of the invention is that it contains a rotatable mechanism that contains more than one Coanda screen with different void ratios and contains a motor that can rotate the mechanism and place the most suitable screen on the intake structure with respect to the measured sediment concentration in the incoming flow. Also, this system is controlled by a decision making computer code specifically written for this product.

Description of the Figures:

The invention will be further described with reference to the accompanying drawings so that the features of the invention can be clarified. However, it is not intended to limit the invention to these particular descriptions and regulations. On the contrary, it is also intended to cover all alternatives, modifications, and equivalents that may be included within the scope of the invention as defined by the appended claims. It should be understood that the details shown are for illustrative purposes only and they are intended to provide the most useful and easy way to understand a description of both the frame of the methods and the conventions and conceptual features of the invention. In these figures,

Figure - 1 The body side view of the autonomous Coanda type water intake structure, which is the subject of the invention. Figure - 2 The mechanism is the top view of the autonomous Coanda type water intake structure, which is the subject of the invention.

Figure - 3 The view of the autonomous Coanda type water intake structure, which is the subject of the invention, together with the mechanism. Figure - 4 The side view of the autonomous Coanda type water intake structure, which is the subject of the invention.

Figure - 5 Perspective view of the autonomous Coanda type water intake structure which is the subject of the invention. Figures that will help to understand this invention are numbered as indicated in the attached picture and are given below with their names.

Description of the Figures:

I . Autonomous Coanda type water intake structure 10. Body section

II. Mechanism assembly area

12. Downstream water transfer flume

13. Flume for the water withdrawn 20. Rotating mechanism 21. Coanda screens

22. Mechanism assembly slot 30. Motor

40. Turbidity sensor 50. Controller A. Incoming water discharge from the river Description of the Invention:

In this detailed explanation, the autonomous Coanda type water intake structure (1), which is the subject of the invention, is explained with examples for a better understanding of the subject, however they should not be considered as limitiations for the product. In this description, the autonomous Coanda type water intake structure which is classified under the category of bottom intakes and generally preferred in the hydraulic structures in case of drinking water supply, water treatment, and energy production purposes will describe.

The autonomous Coanda type water intake structure (1), which is the subject of the invention, is a structure that contains more than one Coanda screen (21) with different slot widths. This structure measures the turbidity level of the incoming discharge and selects and uses the most suitable Coanda screen (21) type. These Coanda screens (21) are placed on a rotating mechanism (20). This rotary mechanism (20) is placed in the mechanism assembly area (11) located in the autonomous Coanda type water intake structure (1) body (10) seen in Figure 1.

The top view of the rotating mechanism (20) is given in Figure 2. As can be seen in the figure, three Coanda screens (21) that have different design parameters are placed on a rotating mechanism (20). These Coanda screens (21) have different slot width lengths and void ratios. Although three Coanda screens are illustrate in the figure, it is possible to use two or more than three screens. The rotating mechanism (20) is mounted in a rotatable manner on the mechanism assembly area (11) which is located on the body section (10) with its mechanism assembly slot (22). This situation can be seen in Figure 3. The rotating mechanism (20) rotates in accordance with the automation, enabling the desired Coanda screen (21) to be used. The side and perspective images of the autonomous Coanda intake system (1) are given in Figure 4 and Figure 5 respectively. Accordingly, the sediment concentration (turbidity) value of the water (A) coming from the river is measured with a turbidity sensor (40). The sediment concentration data obtained by the measurement is evaluated in a controller (50) and classified in various ranges as low, medium, and high sediment concentrations. One of the Coanda screens (21) on the rotating mechanism (20) is selected by the controller (50) according to a suitable sediment concentration class. The motor (30) rotates the rotating mechanism (20) to activate the Coanda screen (21) selected by the controller (50). In case of a change in the sediment concentration value measured by the turbidity sensor (40), the controller (50) sends a signal to the motor (30) again and a new Coanda screen (21) is activated by the motor (30).

In the invention, the number of intervals (low, medium, high) used in the selection of the Coanda screen (21) is equal to the number of the screen (21). The values of these ranges are determined by the user and can be changed. The water coming from the river (A) is filtered in the Coanda screen (21) and directed to the flume for the water withdrawn (13) from the screen. Since the water that cannot be withdrawn from the screen passing over the Coanda screen (21) is not cleaned, it is transferred to the downstream of the river with the downstream water transfer flume (12).