JP4758840B2 - Slurry erosion resistant fluid machine component and fluid machine having the component - Google Patents

Description

  The present invention relates to a slurry erosion-resistant fluid machine part, and more particularly, suitable for surface treatment of parts used in fluid machines such as pumps and water turbines, where slurry erosion causing objective wear due to slurry or the like becomes a problem. The present invention relates to a slurry erosion-resistant coating, a fluid machine component having such a coating, and a fluid machine having the component.

  In fluid machines such as pumps and water wheels that handle liquids such as water containing granular earth and sand, rotating members such as impellers and runners that operate in the fluid, or constituent members that form fluid flow paths, are in contact with the fluid. Therefore, it is necessary to use a material excellent in slurry erosion resistance in order to prevent abrasion of the steel. However, such a material excellent in resistance to slurry erosion is not only expensive, but also has a problem that it lacks other mechanical strength when used alone. Usually, in consideration of performance, cost, repair, etc., a hard sprayed coating is deposited on the surface of the base material constituting the fluid machine part to a desired thickness to protect the base material from abrasion. As a material for such a hard sprayed coating, a cermet material, which is a composite material of ceramics and metal, has been widely used.

  So far, since harder materials generally have better slurry erosion resistance, materials have been developed in the direction of containing as much ceramic hard particles as possible. However, when the content of the ceramic hard particles is increased, the content of the metal part as the binder is decreased, the workability is deteriorated, and the coating is easily cracked. In addition, the thermal spraying of such hard particles adds heat of 400 ° C. or higher to the base material, which may be accompanied by alteration or deformation of the base material, and may require post-treatment such as heat treatment or correction processing after spraying. is there.

On the other hand, polymer lining materials such as polyurethane and FRP are generally widely used for the purpose of improving anti-corrosion or sliding wear resistance for fluid machinery parts whose base material is iron-based material. It has been. These polymer-based lining materials have the advantage that they can be applied at room temperature or at temperatures as low as 200 ° C or less, so that they do not easily cause deterioration or deformation of the base material, but they are resistant to slurry erosion (solid particles are included at a certain rate) In many cases, the erosion wear performance of the slurry fluid is less than that of the base material.
JP 2004-10974 JP 2003-321661 A

  Accordingly, an object of the present invention is to provide a fluid machine component having a polyurea resin lining and a component thereof that has a slurry erosion resistance exceeding that of the base material and can be applied at room temperature, and is not altered or deformed. A fluid machine is provided.

  The present invention relates to the fluid machine component, wherein at least a surface in contact with the fluid is a fluid machine component made of steel, a steel plate, cast iron, or cast steel, and the fluid contact surface is subjected to polyurea resin lining. .

  In the present invention, the fluid machine is a machine having components that rotate mainly in a liquid such as water, and examples thereof include a pump and a water wheel. The fluid machine component of the present invention is a component that is particularly susceptible to erosion by the fluid among the components used in such a fluid machine. For example, in addition to rotating members such as impellers and runners that operate in the fluid, fluid Guide vanes, diffusers, volutes, piping members, and the like that form the flow paths. Among such fluid machine parts, in particular, those in which the surface in contact with the fluid (referred to as “fluid contact surface” in the present invention) is formed of steel, steel plate, cast iron, or cast steel is the subject of the present invention. A part having a fluid contact surface formed of another material such as another metal, hard plastic, or ceramic may be used. Any kind of steel such as carbon steel, alloy steel, rimmed steel, capped steel, killed steel may be used as the base material for the fluid contact surface. In addition to the shaped steel plate, various shapes such as a coil shape and a cylindrical shape are used. As cast iron, gray cast iron, spheroidal graphite cast iron, malleable cast iron, alloy (special) cast iron, white cast iron or the like having a C content of 2.1% or more can be used.

  When the fluid contact surface of the fluid machine component comes into contact with a fluid containing a granular solid, it may be subject to abrasion by the particulate material. Therefore, the lining of the present invention is preferably applied for the purpose of preventing abrasion.

The first consideration in selecting a lining material is the durability of the lining. Since the fluid machine according to the present invention may be used in a fluid containing sand mud or the like, particularly in water as described above, it needs to have a certain level of water resistance. The water resistance of the lining material can be confirmed by an immersion test of the resin lining material. The immersion test method for resin lining materials is based on the immersion test method for lining materials at a uniform temperature described in "Corrosion resistance of plastics and its test and evaluation" (author: Kei Okuda, publisher: Nikkan Kogyo Shimbun). went. A test piece is attached to the stainless steel cell described in FIG. 1 and brought into contact with water in the cell, and the cell is held in a thermostatic bath at 20 to 25 ° C. Observe at regular intervals and continue the test until the lining material is blistered, cracked, etc., and the base metal is clearly corroded and cannot be used. The diffusion coefficient can be determined as follows:
Q (mg or mg / cm ² ) is the weight increase after the time t (hour) when the test piece having the lining film thickness l (cm) is brought into contact with water, and Q is the weight increase after a sufficient time has passed. The diffusion coefficient is D (cm ² / hour), the test result is plotted on a weight change curve as shown in FIG. 2, and the initial gradient is read. The slope in FIG. 2 is 1.836 × 10 ⁻³ , which is

Formula 1

Therefore, the diffusion coefficient D is calculated as 2.54 × 10 ⁻⁶ cm ² / h.

  The durability time of the lining material can be predicted from the diffusion coefficient D thus determined.

  For example, assuming that the material used in the plot of FIG. 2 has a lining film thickness l = 0.3 (cm) and the water absorption amount is almost saturated, q / Q = 0.99, Equation 1 to t 38 months.

The durability time of the lining film thus determined is preferably at least 12 months. Accordingly, the value of the diffusion coefficient D corresponding to this is 7.91 × 10 ⁻⁶ , that is, the lining material suitable for the fluid machine of the present invention is a substance having a diffusion coefficient of 1.0 × 10 ⁻⁵ or less. It turns out that it is desirable.

  Next, an important characteristic required for the lining material used in the fluid machine component of the present invention is slurry erosion resistance. The slurry erosion resistance of the lining material can be confirmed by a slurry wear test. In order to measure the degree of wear due to slurry erosion of the lining material used in the fluid machine component of the present invention, a test is performed using the jet slurry wear test apparatus shown in FIG. The test is performed using a simulated slurry in which JIS No. 9 silica sand (average particle size of 80 μm) having a large average particle size is dispersed in water at 1% by weight for the acceleration test. The slurry is ejected from a nozzle having a diameter of 3 mm that is mounted opposite to a position 25 mm away from the surface of the test piece, and is caused to collide with the test piece to cause damage. The slurry flow rate is 40 m / sec, and the slurry temperature is maintained at 20 to 35 ° C. via a thermostatic device. Before and after the test, the maximum wear depth is measured by measuring the cross-sectional curve on the surface of the test piece, and the wear progress rate by the slurry is obtained. Since 13 chromium steel, SUS316 steel and the like, which are general base materials for fluid machine parts of the present invention, have a maximum wear depth of about 500 to 700 (μm / hr), the lining material used in the present invention. The traveling speed of the maximum wear depth is smaller than this, that is, about 500 (μm / hr) or less, preferably 200 (μm / hr) or less.

  One of the major factors in selecting the lining material is the curing time of the coating film and the ease of construction when the lining material is applied to the fluid machine component of the present invention. Since the fluid machine component of the present invention has a complicated structure such as an impeller and there may be a portion where it is not easy to apply the lining material, what is cured immediately after application of the lining material (for example, in a few seconds) A uniform coating film without bubbles cannot be produced. When lining a part with a complicated structure, a spraying device such as a spray can be used on a wide coating surface, but brushing may be required for curved surfaces and parts with complicated structures. is there. Therefore, it is suitable that the curing time of the resin is about 10 minutes or more, preferably about 15 minutes or more. On the other hand, the resin curing time is preferably within 1 hour in order to prevent the film from sagging or the uniform film from being applied.

  The lining material for fluid machine parts of the present invention comprehensively considers the above-mentioned requirements, that is, has an appropriate water diffusion coefficient, excellent slurry erosion resistance, and has a suitably long curing time and is easy to install. One material is polyurea resin. The lining material of the present invention preferably uses a polyurea resin obtained by curing a polyamine component and a polyisocyanate component. The polyurea resin is a thermosetting resin obtained by combining the amino group portion of the polyamine component and the isocyanate group of the polyisocyanate component to form a urea bond, and has a suitable curing time, moisture in the air, It is known that a coating film formed from a polyurea resin is not easily affected by moisture and is excellent in chemical resistance and acid resistance. Further, it can form a relatively hard coating film having elasticity, is excellent in slurry erosion resistance, and is optimal for the fluid machine component of the present invention.

The polyamine used for forming the polyurea resin used in the present invention is an aliphatic polyamine or an aromatic polyamine having two or more polymerizable amino groups in the molecule. Polyethers such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and the like, polyoxypropylene diamine, polyoxypropylene triamine, etc. as the aliphatic polyamine, polyethers in which the terminal -OH group of the above polyether polyol is changed to an amino group Polyamines, mensendiamine, isophoronediamine, norbornenediamine, bis (4-amino-3-methyldicyclohexyl) methane, diaminodicyclohexylmethane, bis (aminomethyl) cyclohexane, N-aminomethylpiperazine, 3,9-bis (3 -Aminopropyl) 2,4,8,10-tetraoxaspiro (5,5) undecane and other alicyclic polyamines and the like Aromatic polyamines include, for example, polyethylene glycol (4-aminobenzoate), polyethylene glycol bis (2-aminobenzoate), polyethylene glycol bis (3-aminobenzoate), polytetramethylene glycol bis (4-aminobenzoate), polytetramethylene glycol bis (2-aminobenzoate) ), Polypropylene glycol bis (4-aminobenzoate), polypropylene glycol bis (2-aminobenzoate), poly (oxyethylene-oxypropylene) glycol bis (4-aminobenzoate), poly (oxyethylene-propylene ether) glycol bis ( 4-aminobenzoate), polyoxybutylene glycol bis (4-aminobenzoate), polytetramethylene glycol bis (3,5-diaminobenzoate), poly Lopylene ether glycerol tris (4-aminobenzoate), polypropylene ether pentaerythritol tetrakis (4-aminobenzoate), polyoxyethylene bis (4-aminobenzamide), polyoxypropylene bis (4-aminobenzamide), polyoxybutylene glycol bis (4-aminobenzoate), polyoxypropylene bis (3,5-aminobenzamide) and the like. These may be used alone or in combination of two or more.

  Among them, polytetramethylene glycol bis (4-aminobenzoate), polypropylene glycol bis (4-aminobenzoate), poly (oxyethylene-propylene ether) glycol bis (4-aminobenzoate), polyoxybutylene glycol bis (4- Aminobenzoate) is preferred.

  The aromatic polyamine is preferably an aromatic diamine having two primary amino groups bonded to an aromatic ring in the molecule. Since the amino group bonded to the aromatic ring is less reactive than the aliphatic amino group, a primary amino group is preferable in order to sufficiently react with the isocyanate group.

  The aromatic polyamine is, for example, a known nitro compound obtained by reacting a polyol or a terminal amino group-containing polyol with an equivalent amount of nitrobenzoyl chloride, dinitrobenzoyl chloride or trinitrobenzoyl chloride in the presence of a dehydrochlorinating agent. It can be obtained by a method of reducing by a method, a method of reacting a polyol or a terminal amino group-containing polyol and an equivalent isatoic anhydride. These polyamines can be used alone or in combination of two or more.

  The polyisocyanate used for forming the polyurea resin used in the present invention is an aliphatic polyisocyanate or an aromatic polyisocyanate having two or more polymerizable isocyanate groups in the molecule. Examples of the polyisocyanate component include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, 1,2- Phenylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1,4-naphthalene diisocyanate, 1,5-naphthalene diisocyanate, chlorophenylene-2,4-diisocyanate, 4,4′-diphenyl ether diisocyanate, 3, 3′-dimethyldiphenylmethane-4,4′-diisocyanate, 3,3′-dimethoxydiphenyl-4,4′-diisocyanate, o-xylene diisocyanate, m Aromatic diisocyanates such as xylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 2, -methyl-1,5-pentamethylene diisocyanate, 2,2,4-trimethyl-1,6-hexa Aliphatic diisocyanates such as methylene diisocyanate, 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, decamethylene diisocyanate, lysine diisocyanate, 1,4-cyclohexyl diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate And alicyclic diisocyanates such as norbornene diisocyanate.

  In addition, modified polyisocyanates containing one or more uretdione bonds, isocyanurate bonds, allophanate bonds, biuret bonds, uretonimine bonds, carbodiimide bonds, urethane bonds, urea bonds, and the like obtained by modifying these polyisocyanates can also be used. Furthermore, polyisocyanates such as polyphenylene polymethylene polyisocyanate and crude toluene diisocyanate can also be used. These polyisocyanates can be used alone or in combination of two or more.

  Of the fluid machine parts of the present invention, at least the surface that comes into contact with the fluid is formed of steel, steel plate, cast iron, or cast steel, and is lined with a polyurea resin. The method of lining construction by polyurea resin can be performed by a conventionally performed method. For example, the fluid contact surface to be lined may be subjected to a primer treatment with an epoxy resin or a urethane resin, if necessary, and then sprayed while mixing a polyamine component and a polyisocyanate component. For example, a polyamine component and a polyisocyanate component are collided at the tip of a spray spray nozzle and mixed, and then sprayed by a collision mixing system in which the fan is spread and sprayed, or the polyamine component and the polyisocyanate component are placed in the spray nozzle. Mechanical construction such as spraying by a static mixer system in which the mixture is passed through the spiral groove and mixed and sprayed with the mixture is suitable. As a device for performing such spraying, a commercially available mixed coating gun for a high-pressure two-component collision mixing type spraying device, a high-pressure two-component mixing type spraying device, an automatic quantitative mixing spray device, or the like can be used. It is also possible to apply using a coating machine. In addition, as described above, when applying to a component having a complicated structure such as a pump impeller or a water wheel runner, it can be partially applied by a method such as brushing.

  The mixing ratio of the polyamine component and the polyisocyanate component may vary depending on the desired lining strength, hardness, elasticity, and polyamine and polyisocyanate used, but is preferably 3: 1 to 1: 3, more preferably 1: 1. is there. When polyoxypolypropylenediamine and isophorone diisocyanate, which are particularly preferred as the lining applied to the fluid machine component of the present invention, are used, the preferred mixing ratio is 1: 1.

  After spraying or coating, the polyurea resin is dried at room temperature to form a desired lining.

  The above-described lining construction work can be performed near room temperature, and the lining construction surface is not substantially altered or deformed. Therefore, post-treatment after construction as in the conventional lining becomes unnecessary, and lining construction can be performed in a state in which the parts are finished in the final shape.

  The lining of the fluid machine component of the present invention has a small amount of wear due to slurry erosion, and particularly less than the amount of wear of steel, steel plate, cast iron or cast steel forming the fluid contact surface. As described above, the amount of wear due to slurry erosion is the amount that can be confirmed by the slurry wear test. More specifically, the fluid containing the particulate component is ejected and collided with the specimen to be examined. It is a value that can be confirmed from the progress speed of the maximum wear depth observed when an object is damaged.

  The fluid machine component lining of the present invention can be applied multiple times. By applying thin and multiple layers, the porosity of the entire lining film can be reduced. The thickness of one layer of the multilayer film is preferably 0.2 to 3.0 mm, more preferably 0.2 to 2.0 mm, and it is preferable to have a laminated structure. If it is 0.2 mm or less, it is too thin to be applied uniformly with high precision, and unevenness is produced. Moreover, when the thickness of the layer is 3.0 mm or more as a whole, it is too thick and affects the performance of the pump. Furthermore, it is preferable that the ratio of pores existing in the lining film is 10% or less. This is because the smaller the proportion of pores in the lining film, the denser the film. If the pore ratio is too large, water will permeate, the lining material will bulge and crack, and the base material will corrode.

The lining material applied to the fluid machine component of the present invention preferably has a water diffusion coefficient of 1.0 × 10 ⁻⁵ or less. As described above, the water-resistant diffusion coefficient can be calculated by the immersion test of the lining material, and is a measure of durability when the lining material is exposed to water. As described above, the smaller the water diffusion coefficient, the higher the water resistance. Since the fluid machine component of the present invention is intended to be used in a fluid, particularly in water, the water resistance of the lining material is an important factor when selecting the monomer of the polyurea resin.

The present invention also relates to a fluid machine using the fluid machine part described above as a component. Examples of the fluid machine parts of the present invention include guide vanes, diffusers, volutes, and pipe interiors that can come into contact with fluids, as well as parts that rotate in the fluid, such as pump impellers and water wheel runners. Examples of the fluid machine include a pump, a water wheel, and a valve that include these parts as constituent parts.
〔The invention's effect〕

  Since the fluid machine component of the present invention is provided with a dense polyurea resin lining excellent in chemical resistance and acid resistance, it has high slurry erosion resistance. Polyurea resin lining can be easily applied by, for example, a two-component mixed spraying method or a general coating method, and can be applied at around room temperature. No post-processing is required. The fluid machine using the fluid machine part of the present invention is excellent in slurry erosion resistance and can have a long life.

  As an example of the fluid machine according to the present invention, FIG. 4 shows a vertical pump (cross-sectional view). In the figure, a pump 30 includes a casing 31 that defines a pump chamber 32 that houses the impeller 1 according to the present invention, a main shaft 37 that is arranged with the axis line vertical and the impeller 1 is fixed to the lower end, A main bearing 38 that is mounted above the casing and rotatably supports the main shaft 37 with respect to the casing, and a sealing device 39 that prevents leakage of fluid from between the casing 31 and the main shaft 37 are provided. The casing 31 is fixed on the tubular support base 40 by a known method. The casing 31 includes an upper disk-shaped end plate 33, a casing body 34 that defines a spiral volute 35, and a tubular cover 36. A cylindrical suction pipe 41 is connected to the lower end of the cover 36. In the above pump, when the impeller 1 fixed to the lower end of the main shaft 37 is rotated, the fluid is sucked into the inlet 10 of the impeller as indicated by the arrow X in the suction pipe 41, and the impeller 1 is pushed out in the radial direction through the flow path 7, passes through the diffuser 9, and flows into the volute 35. The fluid in the volute is discharged from an outlet (not shown). In accordance with the present invention, the impeller subjected to the lining treatment with the polyurea resin has an excellent slurry erosion resistance because the lining treatment is applied to the entire fluid contact surface where abrasion occurs. Therefore, even when a liquid containing fine particles such as sand is handled, excellent slurry erosion resistance performance is presented.

  Examples for illustrating the effects of the present invention are described below, but the present invention is not limited to the embodiments.

The lining material immersion test method, as explained earlier, is the immersion of the lining material at a uniform temperature as described in "Plastic corrosion resistance and its test and evaluation" (author: Kei Okuda, publisher: Nikkan Kogyo Shimbun). It carried out according to the test method. A test piece was attached to the stainless steel cell shown in FIG. 1 and brought into contact with water in the cell, and the cell was held in a thermostatic bath at 25 ° C. Observations were made at regular intervals, and the test was continued until the lining material was swollen and cracked, and the base metal was clearly corroded and could not be used. The diffusion coefficient was obtained by calculation according to the formula described above.
Measurement Method 2 Slurry Wear Test In order to measure the degree of wear due to slurry erosion of the fluid machine component of the present invention, a test was performed using the jet type slurry wear test apparatus shown in FIG. As described above, the test was performed using a simulated slurry in which JIS No. 9 silica sand (average particle size of 80 μm) having a large average particle size was dispersed in water at a rate of 1% by weight for the acceleration test. The slurry was ejected from a nozzle having a diameter of 3 mm that was mounted opposite to a position 25 mm away from the surface of the test piece, and was damaged by colliding with the test piece. The slurry flow rate was 40 m / sec, and the slurry temperature was kept at 20 to 35 ° C. via a thermostatic device. Before and after the test, the maximum wear depth was measured by measuring the cross-sectional curve on the surface of the test piece, and the wear progress rate by the slurry was determined.
Examples and Comparative Examples Preparation of Test Pieces Test pieces simulating the fluid contact surface of the fluid machine component of the present invention were prepared as follows.
A plate of 13 chrome cast steel (ASTM CA6NM) having a diameter of 80 mm and a thickness of 4 mm was ground-treated. Next, polyurea polypropylene diamine as the main component of polyamine and isophorone diisocyanate as the main component of polyisocyanate are mixed at a ratio of 1: 1 and sprayed onto the test piece. Resin lining was applied. The lining process was performed twice to form a two-layer film. The average layer thickness was 2.0 mm overall. This test piece was used as Example 1 of the present invention and subjected to the above-described slurry wear test and lining material immersion test.

The following test pieces were prepared as comparative examples:
Comparative Example 1: The 13 chrome cast steel sheet, which is the base material used in Example 1 above, was used as a test piece without any treatment.

  Comparative Example 2: A stainless steel plate (SUS316) was used as a test piece without being treated.

  Comparative Example 3: A test piece prepared in the same manner as in Example 1 except that polyurethane lining was applied was used. The construction of polyurethane lining (trade name: Evacoat, company name: Ebara Manufacturing Co., Ltd.) was conducted by mixing the polyisocyanate component and the polyol component in a ratio of 1: 1 using the same two-component mixing spraying apparatus as in Example 1, and 13 chromium. This was done by spraying on a cast steel sheet. The number of sprays was the same as in Example 1, and the average layer thickness was 2.0 mm as a whole.

  Comparative Example 4: A test piece prepared in the same manner as in Example 1 except that rubber lining was applied was used. The construction of the rubber lining was carried out by vulcanizing chloroprene rubber (product name: Hamarok Y-09, company name: Yokohama Rubber), spraying it on the test piece used in Example 1, and baking it at 200 ° C. The number of rubber lining treatments was 1, and the average layer thickness was 2.0 mm.

  Each test piece was subjected to a slurry wear test and a lining material immersion test, and the results are shown in Table 1.

  The rubber lining has a problem in workability, and as shown in Table 1, it is understood that the polyurea resin lining is optimal when considering the slurry erosion resistance and the durability (water resistance) of the lining.

  Fluid machinery having components that rotate in a fluid that can contain solid particulate matter such as granular earth and sand, or any industry that uses such machinery, such as pumps, water wheels, valves, etc. (agriculture, forestry and fisheries, mining) In various energy industries, etc., the fluid machine component of the present invention and the fluid machine having the same can be used effectively.

It is the schematic of a lining material immersion test apparatus. It is a graph showing the example of the weight change curve of the lining material in a lining immersion test. It is the schematic of a jet-type slurry abrasion test apparatus. It is sectional drawing of an example of the pump as a fluid machine provided with the impeller which is a fluid machine component of this invention.

Claims (4)

At least the surface that contacts the fluid is a fluid mechanical component made of steel, steel plate, cast iron, or cast steel, the fluid contact surface is subjected to polyurea resin lining , the lining is a multilayer film, and the film thickness of each layer is 0.2. The fluid machine component according to claim 1, wherein the ratio of pores existing in the membrane is 10% or less . At least the surface in contact with the fluid is a fluid mechanical part made of steel, steel plate, cast iron or cast steel, and the fluid contact surface is subjected to polyurea resin lining, and the water diffusion coefficient of the lining is 1.0 × 10 ⁻⁵ or less The fluid machine component according to claim 1, wherein 3. The fluid machine component according to claim 1 , wherein the amount of wear due to slurry erosion of the lining is less than the amount of wear due to slurry erosion of steel, steel plate, cast iron, and cast steel. Fluid machine having a fluid machine component according to any one of claims 1-3.

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