Technical Field

The present invention relates to a double eccentric butterfly valve shaft structure with reduced fluid resistance and also provides fluid control and weight gain by using liquid and gas pipelines.

Prior Art

Butterfly valves are valves providing control of fluids that disable and enable the flow on the line by rotating 90° a flat throttle that is seated eccentrically or from its center. They have different driving systems such as hand wheel, electric, hydraulic or, pneumatic actuator. Butterfly valves are frequently preferred in the sector due to their advantages such as being light, having short assembly lengths, and enabling relatively free/comfortable passage of fluid. The shaft in the butterfly valve body bearings and the throttle, whose angle can be adjusted by means of said shaft, are the moving components of the valve that limit or prevent the flow. The throttle is fixed to the butterfly valve shaft, preventing it from coming out of the body and enabling it to operate in its current position. Due to the throttle structure in the state of the art, the flow does not move with a uniform velocity distribution and a constant acceleration. Therefore, vortices occur in the flow and cause vibration in the flow line. In this case, the resulting vortices create a risk of damage to the throttle and shaft and cause irregular flow.

In the state of the art, the shafts placed in the throttle bearings form a protrusion in the form of a throttle. The valve flow cross-sectional area is narrowed in the regions where these shaft bearing protrusions are located opposite each other in the butterfly valve flow line. Body bearings in butterfly valves prevent the shafts from being damaged against fluid pressure and retain the hydrodynamic throttle in place. All forces due to flow and fluid pressure are transmitted to the body bearings via shafts. In addition to all these, in the developments made in the throttle forms in the state of the art, the shaft structures have been preferred as one-dimensional within the valve protrusions. The throttle protrusions caused by the shafts used in the prior art cause high pressure loss values by reducing the flow cross-sectional area. The flow coefficient and flow resistance values were compared by reviewing the state of the art.

As a result, it has been envisaged that a new shaft structure can improve the throttle form available in the state of the art and contribute to the solution of the above-mentioned problems. The inadequacy of the available shaft structures necessitated an R.&D study in the relevant technical field.

Objects of the Invention

The present invention solves all of the above-mentioned problems at the same time, and it is an innovative approach by changing the shaft structure in order to make the throttle shaft bearing smaller and developing a shaft structure whose diameter gradually decreases towards the center of the throttle due to the limited areas that can be developed in valve technologies.

The object of the present invention is to reduce the throttle protrusions caused by the shaft structure used in the available butterfly valves and to increase the flow area.

Detailed Description of the Invention

The figures of double eccentric butterfly valve system, which is the subject of the invention, are as follows:

Figure - 1 illustrates the closed isometric general view of the double eccentric butterfly valve.

Figure - 2 illustrates the open isometric partial section view of the double eccentric butterfly valve.

Figure - 3 illustrates the flow sectional view of the double eccentric butterfly valve.

Figure - 4 illustrates the isometric sectional view of the double eccentric butterfly valve. Figure - 5 illustrates the sectional detailed view of the double eccentric butterfly valve.

Figure - 6 illustrates the sectional view of bearings in the double eccentric butterfly valve.

Figure - 7 illustrates the close isometric sectional view of the sealing rubber and compression ring.

Figure - 8 illustrates the view of the stepped shaft structure.

Reference Numerals:

1. Double Eccentric Butterfly Valve

2. Body

3. Hydrodynamic Throttle

4. Stepped Shaft

5. Bearings

6. Sealing Rubber

7. Compression Ring

Figure - 3 shows the inventive shaft structure, the diameter of which gradually decreases towards the center of the throttle. The aforementioned shaft structure, whose detailed explanation is given below, is described as a stepped shaft (3). (Figure 8)

Figure - 1 shows the butterfly valve (1) that is used in liquid and gas pipelines and that provides fluid control. The butterfly valve (1) in its most general form consists of the body (2), the throttle (3), and the shafts (4). In the new technical shaft design, a shaft structure with at least two stages has been developed in order to minimize the effects of the throttle protrusions that adversely affect the flow, which are found in conventional butterfly valves. As a result of this development, the valve protrusions have been reduced by means of the stepped shaft structure by providing the same strength criteria. The position of said hydrodynamic throttle (3) inside the body (2) is provided by the stepped shafts (4) seen in Figure 3 and Figure 5. Thus, the hydrodimaic throttle (3) works in accordance with the functional movements thereof in the body in its position. Said stepped shafts (4) contain at least one step whose diameter gradually decreases starting from the larger one. the hydrodynamic throttle (3), whose hydrodynamic feature is improved by reducing the protrusion height of the throttle shows minimum resistance to the flow and increases the flow efficiency thereof by means of the special stepped structure of the stepped shafts (4). Thus, the height of the junction of the parts has been reduced by means of the compatibility of the stepped shaft (4) and the hydrodynamic throttle (3), and the present invention improves the flow coefficient in a positive way.

As a result of computational fluid dynamics analysis results, it was observed that the flow coefficient has been improved in a positive way by means of said stepped shaft (4) and hydrodynamic throttle (3). As a result of computational fluid dynamics analyzes of hydrodynamic throttles (3) and stepped shafts (4), whose 3D modeling for DN 1000 and DN 200 diameters are made, it has been calculated that there is an improvement of 80% and more for DN 1000, and 95% and more for DN 200 in flow coefficient Cv values. It was determined that the results of these analyzes exceeded the flow coefficient values measured in the available butterfly valves and reached the highest flow coefficient values.

The general position of the stepped shafts (4) and the pressure ring (7) can be seen in the double eccentric butterfly valve with the stepped shaft (4) structure shown in Figure - 2. Said pressure ring (7) is positioned on the throttle in the inner section of the body (2). The hydrodynamic throttle (3) seen in Figure 2 is positioned in the middle of the valve body (2) by means of the stepped shafts (4). The stepped shafts (4) placed in the butterfly valve system provide the angular movement of the throttle (3), which has the duty of limiting or preventing the flow.

Minimization of the friction between said stepped shafts (4) and the bearings (5) is achieved by selecting the material of said stepped shafts (4) and the selflubricating preparation of said bearings (5) with the material selections.

The fact that the shaft structures used in the state of the art are placed in the slot flatly and have a thicker structure cause an increase in the weight of the valve and shaft, and this situation causes problems in valve systems.The customized structure of the stepped shaft (4), which is the subject of the invention, ensures that said stepped shaft (4) is not damaged by the flow rate, and also makes the use of the butterfly valve long-lasting. Said hydrodynamic throttle (3) used in the butterfly valve system of the present invention eliminates the vibrations that occur in the flow. Thus, a more regular flow is provided.

The bearings (5) positioned on the drive side and the opposite side as at least one of said body (2), as seen in Figure 5 and Figure 6, prevent the said stepped shafts

(4) in the butterfly valve system from vibrating against the fluid pressure. Said bearings (5) also carry the forces formed due to fluid pressure.

The materials of said bearings (5) and said stepped shafts (4) do not limit production by allowing the use of alternative materials.

The sealing rubber (6) structure, which is seen in detail in Figure 7, provides sealing in the butterfly valve system. Said sealing rubber (6) was positioned so as to fully circle around said throttle (3). Said sealing rubber (6) forms the sealing region together with said pressure ring (7) and said hydrodynamic throttle (3). It was ensured that said sealing region elements are fully inserted in its place on said body (2), wherein leaks that may occur due to fluids are also prevented in the use of the butterfly valve in the flow line.

The subject of the invention was formed by attaching said hydrodynamic throttle (3) to the slots in said body (2) from both ends of said body (2) by means of said stepped shaft (4) which is supported in said body (2). Not slipping said stepped shafts (4) is ensured by means of the bearings (5), which have at least one on each side on said body (2). Said stepped shafts (4) are fully seated on said bearings

(5). Said bearings (5), which enable said stepped shaft (4) structure to be seated into said body (2), reduce the roughness value by means of the material structure thereof, and the resistance to fluids is increased. The production materials of said bearings (5) do not limit the production by allowing the use of alternative materials.

Said sealing rubber (6) and said compression ring (7) completely surround the inside of the body and complete the butterfly valve system.

The above-mentioned shaft structure does not limit production by allowing the use of alternative materials, and is made conical or stepped.