JPH0621280B2 - Water wheel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a novel resin composition and a member for flowing water such as a hydroelectric water turbine runner, a guide vane and a stay vane used at a soil containing point as its application. In particular, the present invention relates to a turbine having excellent cavitation erosion resistance and earth and sand abrasion resistance.

[Prior Art] Flowing water parts such as a hydraulic power turbine runner, guide vanes, and stay vanes are damaged by the cavitation due to the shape and flow velocity of the members. For this reason, a stainless steel-based welding alloy for build-up, which is excellent in cavitation corrosion erosion resistance, has been developed as the member material. Their compositions are disclosed in JP-A Nos. 57-152447 and 57-15689, and these materials are used for overlay welding on members. Further, attempts have been made to coat the running water member with a polyurethane-based coating material to suppress erosion of the cavitation.

By the way, the cavitation erosion is a phenomenon in which a high impact pressure when the cavities generated in high-speed running water collapses is applied to the member and erodes the part, and the impact pressure at that time is a flow velocity of 35 to 120 m / m. 514 to 17 in s
It is as high as 45 atm.

As a material for preventing erosion at this time, it is considered that a material having a higher strength than this impact pressure or a material capable of absorbing the impact pressure is preferable, and a stainless steel-based overlay welding material has a high strength and a rubber-based material. The coating of is expected to have the latter effect. Furthermore, in the former weld overlay material, the components are adjusted so that the surface of the flowing water member is work-hardened by utilizing this impact pressure.

On the other hand, in running water containing high sediment, erosion of members by sediment occurs. This erosion is a phenomenon in which the flowing water member is worn due to the cutting action of hard earth and sand such as Al ₂ O ₃ . Generally, it is said that it is possible to prevent erosion without being cut if it is a material having a hardness higher than earth and sand, but until now, it has been known that power turbines are used in high earth and sand containing land,
Since there are relatively few, no materials developed for abrasion by sand are found. Furthermore, in the case of running water containing a high amount of sediment and accompanied by cavitation, erosion or erosion is accelerated rather than a single factor.

[Problems to be Solved by the Invention]

Even with a conventional overlay welding material having excellent cavitation resistance, it is extremely difficult to bring its hardness close to that of earth and sand, and there is a problem that sufficient characteristics cannot be obtained.

An object of the present invention is to solve the above-mentioned drawbacks, and it is an object of the present invention to provide a water turbine using a resin composition having excellent cavitation resistance and earth and sand abrasion resistance.

[Means for Solving the Problems]

Briefly describing the present invention, the present invention is an invention relating to a water turbine, wherein at least a part of a member for flowing water is coated with a resin composition containing at least (A) a rubber-modified epoxy compound, and (B) an aliphatic polyamide polyamine. , Coated with a cured coating layer, cavitation erosion resistance
It is characterized in that a member for running water having excellent earth and sand abrasion resistance is used.

The above object is achieved by coating the surface of a member for running water of a power generation turbine with a rubber-modified epoxy compound or an epoxy resin composition containing a rubber-modified epoxy compound and an inorganic filler.

More specifically, the present invention comprises the following items.

The resin composition preferably contains an inorganic filler and / or a polybutadiene rubber.

Further, it is preferable that the rubber-modified epoxy compound has a polybutadiene, siloxane, fluoroalkyl or fluoroalkyl ether skeleton in an amount of 50 to 70% by weight.

Further, the aliphatic polyamide polyamine has the following formula: [Where R is the following formula: The group represented by, and m and n represent a number of 1 to 100] are preferable.

The inorganic filler is preferably (a) an inorganic filler having an average particle size of 8 to 20 μm and / or (b) a whisker or a mica filler surface-treated with a coupling agent.

Further, the inorganic filler is obtained by adding the (a) / (b) to 8.5 / 1.
It is preferable that the content of the compounding agent is 5 to 9.5 / 0.5, and 70% by weight or less based on the whole composition.

Suitably, the inorganic filler is silica or alumina and the whiskers are potassium titanate, metal or ceramic whiskers.

A water turbine according to the present invention uses the above-described running water member.

The resin composition of the present invention can be gelled and cured at room temperature to form an arbitrary coating layer without sagging phenomenon after coating.
Further, in order to obtain the optimum characteristics, heating may be performed at a temperature of 100 ° C. or lower for 1 to 2 hours.

Hereinafter, the water turbine of the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a hydraulic power generation turbine to which the present invention is applied. The water turbine is composed of a crown 1, a shroud 2, a runner blade 3, a runner cone 4, a guide vane 5, a stay vane 6, a runner liner 7, and a seat liner 8. The running water that has passed through the stay vane 6 is discharged from the guide vane 5 to the runner. It flows to the blade 3, rotates the runner blade 3, and flows downward.

These water turbine members are obtained by ordinary melting and casting, and overlay welding is performed on the surface of the running water portion, which is required to have resistance to cavitation.

With respect to earth and sand wear resistance, first, a high hardness overlay welding metal material was examined, but satisfactory wear resistance was not always obtained. It was found that there is a limit such as cracking due to brittleness when hardness is remarkably increased.

Ceramic is known as a material having a hardness higher than that of metal, and almost no damage was found in the earth and sand wear experiment conducted on silica and alumina ceramic molded products. It is presumed that this is because the hardness of earth and sand is equivalent to that of ceramics and is not subjected to the cutting action of earth and sand. However, it is difficult to attach these ceramics to a flowing water member having a curvature, and the application site is limited.

As a result of various investigations into alternative methods, it was found that a method of coating a running water member with a coating material made of an epoxy resin composition containing a high concentration of inorganic powder can meet this purpose.

An epoxy resin composition containing a high concentration of an inorganic powder is applied to a member, and the hardness of a film cured under predetermined conditions is close to that of a ceramic, and the surface thereof is such that the inorganic powder is arranged almost continuously. Since it was difficult to receive the cutting action by the earth and sand, the earth and sand abrasion resistance was superior to that of metal. Next, when the cavitation resistance of this film was examined, contrary to expectations, the amount of erosion was higher than that of metallic materials. It was judged that the cause was that the inorganic powder particles fell off due to the impact pressure of the cavity because the adhesive strength between the inorganic powder and the epoxy resin was low.

Then, in consideration of improving the strength and imparting viscoelasticity between the inorganic powder and the epoxy resin, an attempt was made to add a liquid rubber as a third substance. As a result, the addition of the liquid rubber was found to reduce cavitation erosion. However, the system in which liquid rubber is simply mixed has low shear strength between the running water member and the film. This is presumably because there is a problem in the compatibility between the epoxy and the liquid rubber. Furthermore, a resin having a high curing temperature or a high temperature heat-curable resin causes a phenomenon of sagging flow before being cured after being applied to a running water member. Some powders impart thixotropic properties, but addition of a large amount thereof causes deterioration of properties.

The epoxy resin used in the present invention is a rubber-modified epoxy resin having a polybutadiene skeleton, and also having a siloxane, a fluoroalkyl or a fluoroalkyl ether skeleton. (R ₁ is Represents a rubber-modified epoxy compound.

Further, when it is desired to add a bis type epoxy resin or a novolak type epoxy resin, which are general-purpose epoxy resins, to these modified epoxies, they can be easily mixed and used. The curing agent is
Aliphatic polyamide polyamines are effective and can suppress the sagging flow after application, which is the purpose. The desired properties can be obtained by first curing at room temperature and then heating at a temperature of 100 ° C. or lower. The composition of the present invention can also be used in combination with a conventionally known curing agent and accelerator for an epoxy compound.

Erosion due to water flow is desired to be relaxed by an elastic body such as rubber, or strong against abrasion due to earth and sand. Therefore, in the case of a polymeric material, it is essential to fill the inorganic powder.

The type of inorganic powder is preferably silica or alumina, and the shape of the particles may be sandy or spherical. It is said that the average particle size is 8 to 12 μm when the particle size of the sand contained in the river is equal to or larger than these particle sizes, and 8 to 20 μm is more effective.

Further, these inorganic fillers can be used as a mixture with various whiskers and mica fillers surface-treated with a coupling agent.

The composition excellent in cavitation resistance in the present invention is adjusted so that the rubber content in the rubber-modified epoxy is 50 to 70% by weight, while the curing agent is 30 to 100 relative to 100 parts by weight of the rubber-modified epoxy. Parts by weight are suitable. Further, if the blending ratio of the inorganic filler is small, the cavitation erosion resistance tends to improve, and if it is large, the earth and sand abrasion resistance tends to improve. For rivers with a small amount of sediment, it is appropriate to place emphasis on cavitation erosion resistance, and it is appropriate to mix the inorganic filler in an amount of 20% by weight or less of the resin composition. For rivers with a lot of sediment, attach importance to soil wear resistance. The mixing ratio of the inorganic filler to the resin composition is 50-
70 wt% is appropriate, and in a river where both cavitation erosion resistance and earth and sand abrasion resistance are important, the blending ratio of the inorganic filler is 20 to 50 wt% with respect to the resin composition.
Is preferred. When the content of the inorganic filler exceeds 70% by weight, the composition becomes viscous and it becomes difficult to apply the composition to a member for running water. On the other hand, if the amount of rubber is too large, the shear adhesive strength with the base material will be low, which is not preferable.

Further, in the present invention, a coupling agent may be blended in order to increase the affinity of the inorganic filler to further improve the practical performance of the film.

By coating and curing these epoxy resin compositions on the surface of each running water member shown in FIG. 1, desired cavitation erosion resistant and earth and sand abrasion resistant coatings can be obtained.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these examples.

Examples 1 to 16 and Comparative Examples 1 to 5 Table 1 shows the compounding compositions of Examples 1 to 16 and Comparative Examples 1 to 5. Epoxy resin, mainly rubber-modified epoxy resin,
Further, a curing agent, an aliphatic polyamide polyamine, and a silane coupling agent, and a predetermined amount of an inorganic filler are added to these compositions, respectively.
After mixing, each coating material was adjusted. The adjusted coating agent was applied to the SuS304 substrate, and a shear test piece, a cavitation, and an abrasion test piece were prepared and tested.

For the cavitation erosion test, a magnetostrictive vibration tester was used. A circular test piece was attached to the tip of the oscillating horn, and the test was performed under the conditions of a resonance frequency of 20 KHz and a maximum amplitude of 200 μm at the tip of the test piece, and the amount of erosion after 1 hour was measured. The sediment wear test was conducted by a water jet method containing sediment. Al ₂ O ₃ powder with an average particle size of 8 μm was used as the sand, and water mixed with 30 g per tap water was jetted from a nozzle with a diameter of 1 mm at a flow rate of 20 m / s and at an angle of 45 ° to a flat plate test piece for 1 hour The amount of wear afterward was measured. Table 1 also shows the tensile shear strength, cavitation erosion amount and sediment wear amount of each film.

In addition, the addition amount of the inorganic powder filler in each example of the following Table 1 is shown by weight% with respect to the resin composition. The curing agent tomide is an aliphatic polyamide polyamine manufactured by Fuji Kasei Kogyo Co., Ltd.

The comparative example is an epoxy resin alone or a system in which an inorganic filler is added thereto. Increasing the blending amount of the inorganic filler increases the shear strength and improves the sand and sand abrasion resistance.

It should be noted that SuS that has been generally used for these running water members
The amount of sediment wear under the same conditions of 304 is 4 × 10 ^-3 cm ³
And the coating of Comparative Example 4 also exhibits better wear resistance than SuS304. On the other hand, the ratio of the inorganic powder to the epoxy resin has only a certain effect on the erosion of the cavitation.

On the other hand, the film of the present invention mainly composed of the rubber-modified epoxy resin viscoelastically relieves the impact pressure caused by the cavitation and the sediment flow. Both cavitation erosion and sediment wear are effectively reduced. In particular, a system that does not include an inorganic filler is excellent in cavitation resistance. That is, it was confirmed that the effect of the rubber component in the rubber-modified epoxy resin was extremely excellent.

〔The invention's effect〕

According to the present invention, a rubber-modified epoxy resin, or an epoxy resin composition in which this composition and inorganic powder are blended, is applied to a running water member of a hydraulic turbine, and by curing,
Since the cavitation resistance, erosion resistance, and earth and sand abrasion resistance can be improved, the reduction in the efficiency of the water turbine can be reduced, and hardening can be exerted to improve its life.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a hydraulic power generation turbine to which the present invention is applied. 1: Crown, 2: Shroud, 3: Runner blade, 4:
Runner cone, 5: guide vane, 6: stay vane,
7: runner liner, 8: seat liner

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI technical display location F03B 11/04 7361-3H (72) Inventor Johinoyoshi Sato 3-chome, 1-chome, Hitachi-shi, Ibaraki No. 1 Hitachi Ltd., Hitachi Works (56) References JP-A-54-38450 (JP, A) JP-A-63-301214 (JP, A) JP-A-58-25324 (JP, A) Kaisho 58-215463 (JP, A)

Claims (1)

[Claims] 1. At least a part of a member for running water is coated with a coating layer obtained by coating and curing a resin composition containing at least (A) a rubber-modified epoxy compound and (B) an aliphatic polyamide polyamine. A water turbine characterized by using a running water member having excellent erosion resistance and earth and sand abrasion resistance.