A runner feeding device for a cast turbine vane

Abstract

This utility model discloses a feeding device for the flow channel of a cast steam turbine stationary blade, belonging to the field of metal investment casting technology. The feeding device includes a pouring cup, an annular runner, conical tubes, and feeding gates. The pouring cup is a conical structure, wider at the top and narrower at the bottom, with its bottom outlet located at the center of the annular runner. The inner wall of the annular runner is connected to the bottom outlet of the pouring cup via multiple centrally symmetrically arranged conical tubes. Multiple feeding gates are symmetrically arranged along the circumference at the bottom of the annular runner. Compared with existing structures, the feeding gates of this device connect to the top large end face of the steam turbine stationary blade, with the small end face facing downwards, thus achieving sequential solidification after the molten steel is poured, ensuring the metallurgical quality of the product. Furthermore, the spacing and symmetrical arrangement of the feeding gates ensure sufficient heat dissipation space for the blades.

Description

Technical Field

[0001] This utility model belongs to the field of metal investment casting technology, and in particular relates to a feeding device for the flow channel of a cast steam turbine stationary blade. Background Technology

[0002] With the development of the power industry and the increasing demands for efficiency in industrial sectors, modern casting technology is constantly advancing. For example, advancements in precision casting have made it possible to manufacture complex-shaped stator blade flow channels. Investment casting, for instance, can achieve high dimensional accuracy and surface quality, providing a technological foundation for designing complex flow channel structures. Simultaneously, numerical simulation technology is increasingly widely used in casting processes. By simulating the filling and solidification processes of molten metal, potential defects in flow channel design, such as shrinkage cavities, porosity, and gas porosity, can be predicted. This guides designers in optimizing flow channels, improving casting quality, and ultimately meeting the high-performance requirements of steam turbines in power generation and industrial applications.

[0003] Investment casting is widely used in many fields because it can produce high-precision castings with complex shapes. However, in actual production, the yield of investment casting is often constrained by various factors, leading to increased costs and resource waste, and presenting the following problems:

[0004] 1) Inappropriate pouring cup design: If the size and structure of the pouring cup are unreasonable, it cannot effectively guide the molten metal into the mold cavity smoothly, causing molten metal splashing and turbulence, leading to gas entrapment and porosity defects, resulting in the scrapping of the casting. At the same time, if the pouring cup has insufficient feeding capacity, it cannot provide enough molten metal to replenish the casting during solidification and shrinkage, which easily produces shrinkage cavities and affects the yield.

[0005] 2) Inadequate sprue design: The diameter, length, and surface roughness of the sprue affect the filling speed and pressure of the molten metal. If the diameter is too small, the filling resistance is high, the molten metal flow rate is slow, and incomplete filling may occur. If the diameter is too large, the molten metal flow rate is too fast, easily eroding the inner wall of the mold shell, causing damage. Furthermore, excessive molten metal concentrates in the sprue, reducing the proportion of molten metal used for casting. A rough sprue surface increases the frictional resistance of the molten metal flow, affecting the smoothness of filling.

[0006] 3) Inappropriate design of the runner and ingate: The cross-sectional shape, size, and distribution of the runner affect the uniformity of the molten metal distribution within the mold cavity. The location, number, and size of the ingate directly affect the direction, speed, and flow rate of the molten metal entering the mold cavity. If the ingate is improperly designed, the molten metal may experience impact and turbulence within the mold cavity, causing localized overheating and resulting in defects such as shrinkage cavities and porosity.

[0007] Therefore, in response to the above-mentioned technical problems, how to design a feeding device for the flow channel of a cast steam turbine stationary blade has become a technical challenge in this field. Utility Model Content

[0008] To address the aforementioned technical problems, this utility model provides a feeding device for the flow channel of a cast steam turbine stator blade, which solves the problems through the following technical means:

[0009] A feeding device for the flow channel of a cast steam turbine stationary blade is characterized in that it includes a pouring cup (1), an annular runner (2), a conical tube (3), and a feeding gate (4), wherein: the pouring cup (1) is a conical structure with a larger upper part and a smaller lower part, and the bottom outlet of the pouring cup (1) is located at the center of the annular runner (2); the inner wall of the annular runner (2) is connected to the bottom outlet of the pouring cup (1) through multiple conical tubes (3) arranged symmetrically at the center; multiple feeding gates (4) are symmetrically arranged along the circumference at the bottom of the annular runner (2), and the feeding gates (4) are connected to the large end face of the steam turbine stationary blade (6).

[0010] Preferably, it also includes an exhaust pipe (5), the bottom of which is connected to the upper surface of the annular gating (2), and the top of which is connected to the upper end of the pouring cup (1).

[0011] Preferably, the height of the pouring cup (1) is in the range of 90 to 100 mm, the diameter of the upper end face of the pouring cup (1) is in the range of 110 to 130 mm, the diameter of the lower end face of the pouring cup (1) is in the range of 40 to 45 mm, and the flange of the pouring cup (1) extends outward by 8 to 10 mm.

[0012] Preferably, the outer diameter of the annular runner (2) is in the range of 250 to 270 mm, the inner diameter of the annular runner (2) is in the range of 140 to 150 mm, and the thickness of the annular runner (2) is in the range of 30 to 40 mm.

[0013] Preferably, the taper of the tapered tube (3) is between 10° and 20°, the large end of the tapered tube (3) is connected to the pouring cup (1), and the small end of the tapered tube (3) is connected to the annular runner (2).

[0014] Preferably, the shape of the feeding gate (4) is consistent with the cross-sectional shape of the large end face of the turbine stationary blade (6), and the outer end face of the feeding gate (4) extends 1 to 2 mm inward compared with the outer end face of the turbine stationary blade (6).

[0015] The feed-in device for the flow channel of the cast steam turbine stationary blade of this utility model has the following beneficial effects:

[0016] This device, guided by the pouring cup and tapered tube, allows molten metal to enter the annular runner rapidly and uniformly, ensuring consistent liquid flow at each feeding gate. A dedicated feeding gate is positioned at the top of each turbine stationary blade, allowing the molten metal to flow smoothly towards the contraction points during solidification, achieving directional solidification. Multiple feeding gates are symmetrically and spaced along the circumference at the bottom of the annular runner, ensuring sufficient heat dissipation space for each blade to control the temperature gradient during solidification, allowing the molten metal to solidify in the intended direction and promoting the feeding process. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 is a schematic diagram of the exhaust pipe structure of this utility model;

[0020] Figure 3 is a schematic diagram of the inside of the pouring cup of this utility model;

[0021] Figure 4 is a schematic diagram of the application of this utility model;

[0022] Figure 5 is a schematic diagram of the feeding gate structure of this utility model;

[0023] Figure 6 is a schematic diagram of the turbine stator blade layout of this utility model.

[0024] Among them, 1-pouring cup, 2-annular runner, 3-conical tube, 4-feeding gate, 5-exhaust pipe, 6-turbine stationary blade. Detailed Implementation

[0025] In the description of this utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0026] The present invention will now be described in detail with reference to the accompanying drawings.

[0027] As shown in Figures 1 to 6, the feeding device for the turbine stationary blade flow channel includes a pouring cup (1), an annular runner (2), a conical tube (3), and feeding gates (4). In the figures, the pouring cup (1) is a conical structure with a larger top and a smaller bottom. The bottom outlet of the pouring cup (1) is located at the center of the annular runner (2). The inner wall of the annular runner (2) is connected to the bottom outlet of the pouring cup (1) through multiple conical tubes (3) arranged symmetrically at the center. The number of conical tubes (3) can be three or more. Multiple feeding gates (4) are symmetrically arranged along the circumference at the bottom of the annular runner (2). The feeding gates (4) are connected to the large end face of the turbine stationary blade (6). The number of feeding gates (4) can be six to nine.

[0028] In this embodiment, two or more symmetrically arranged exhaust pipes (5) are also included. The bottom of the exhaust pipe (5) is connected to the upper surface of the annular gating channel (2), and the top of the exhaust pipe (5) is connected to the upper end of the pouring cup (1).

[0029] In practical applications, the height of the pouring cup (1) ranges from 90 to 100 mm, the diameter of the upper end face of the pouring cup (1) ranges from 110 to 130 mm, the diameter of the lower end face of the pouring cup (1) ranges from 40 to 45 mm, and the flange of the pouring cup (1) extends outward by 8 to 10 mm. In this example, the height of the cup is 95 mm, the diameter of the upper end face of the cup is 120 mm, the diameter of the lower end face is 42 mm, and the flange of the cup extends outward by 10 mm.

[0030] In practical applications, the outer diameter of the annular runner (2) ranges from 250 to 270 mm, the inner diameter ranges from 140 to 150 mm, and the thickness ranges from 30 to 40 mm. In this example, the outer diameter of the annular runner is 265 mm, the inner diameter is 145 mm, and the thickness is 35 mm.

[0031] In practical applications, the taper of the tapered tube (3) ranges from 10° to 20°. The large end of the tapered tube (3) is connected to the pouring cup (1), and the small end of the tapered tube (3) is connected to the annular runner (2). In the figure, the pouring cup is connected by three 15° tapered ribs.

[0032] In practical applications, the shape of the feeding gate (4) is consistent with the cross-sectional shape of the large end face of the turbine stationary blade (6). The outer end face of the feeding gate (4) extends 1 to 2 mm inward compared to the outer end face of the turbine stationary blade (6). The feeding gates (4) are spaced 25 to 35 mm apart to ensure sufficient heat dissipation space between the turbine stationary blades and to ensure the drying of each layer of coating during the production process.

[0033] It should be noted that, under the guidance of the pouring cup and tapered tube, the molten metal can enter the annular runner quickly and evenly, ensuring the consistency of the poured liquid at each feeding gate. A dedicated feeding gate is installed at the top of each turbine stationary blade, allowing the molten metal to flow smoothly to the contraction area during solidification, achieving directional solidification. Multiple feeding gates are spaced and symmetrically arranged at intervals along the circumference at the bottom of the annular runner, ensuring sufficient heat dissipation space for each blade to control the temperature gradient during solidification, allowing the molten metal to solidify in the intended direction and promoting the feeding process.

[0034] The above design improvements can enhance the casting quality of the flow channels for the stationary blades of small steam turbines, reduce defects, improve blade performance and reliability, and lower production costs. They may also help improve the overall efficiency and operational stability of small steam turbines.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A feeding device for the flow channel of a cast steam turbine stationary blade, characterized in that, It includes a pouring cup (1), an annular runner (2), a tapered tube (3), and a feeding gate (4), wherein: The pouring cup (1) is a conical structure with a larger top and a smaller bottom, and the bottom outlet of the pouring cup (1) is located at the center of the annular runner (2); The inner wall of the annular runner (2) is connected to the bottom outlet of the pouring cup (1) through multiple centrally symmetrically arranged conical tubes (3); The bottom of the annular runner (2) is symmetrically provided with multiple feeding gates (4) along the circumferential direction, and the feeding gates (4) are connected to the large end face of the turbine stationary blades (6).

2. The feeding device for the flow channel of the cast steam turbine stationary blades according to claim 1, characterized in that, It also includes an exhaust pipe (5), the bottom of which is connected to the upper surface of the annular runner (2), and the top of which is connected to the upper end of the pouring cup (1).

3. The feeding device for the flow channel of the cast steam turbine stationary blades according to claim 1, characterized in that, The height of the pouring cup (1) is 90 to 100 mm, the diameter of the upper end face of the pouring cup (1) is 110 to 130 mm, the diameter of the lower end face of the pouring cup (1) is 40 to 45 mm, and the flange of the pouring cup (1) extends outward by 8 to 10 mm.

4. The feeding device for the flow channel of the cast steam turbine stationary blades according to claim 1, characterized in that, The outer diameter of the annular runner (2) ranges from 250 to 270 mm, the inner diameter of the annular runner (2) ranges from 140 to 150 mm, and the thickness of the annular runner (2) ranges from 30 to 40 mm.

5. The feeding device for the flow channel of the cast steam turbine stationary blades according to claim 1, characterized in that, The taper of the tapered tube (3) is between 10° and 20°. The large end of the tapered tube (3) is connected to the pouring cup (1), and the small end of the tapered tube (3) is connected to the annular runner (2).

6. The feeding device for the flow channel of the cast steam turbine stationary blades according to claim 1, characterized in that, The shape of the feeding gate (4) is consistent with the cross-sectional shape of the large end face of the turbine stationary blade (6), and the outer end face of the feeding gate (4) extends 1 to 2 mm inward compared with the outer end face of the turbine stationary blade (6).

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