CN111532792A - High temperature resistant type closes fan - Google Patents

Abstract

The invention discloses a high-temperature-resistant shut-off fan, comprising: a casing, an inner ring wall of the casing is spaced along its axial direction with a plurality of guide grooves perpendicular to the axial direction, and two sides of the casing are respectively provided with An inlet and an outlet communicated inside the casing; a rotating shaft, the rotating shaft is rotated and installed in the casing along the axial direction, a plurality of blades along the axial direction of the rotating shaft are spaced around the rotating shaft, and the side of the blades facing the inner wall of the casing is provided with guide grooves The convex teeth that guide and match form a sealing pair between the blade and the inner wall of the casing; the surface of the blade is covered with Ni60‑WC laser cladding coating, and Ni60:WC=9:1 (mass ratio of Ni60‑WC laser cladding coating) ). The closed fan of the invention can greatly improve the airtightness of the closed fan, and can achieve better sealing effect at high temperature; the surface of the closed fan blade is formed by laser cladding to form a Ni60-WC laser cladding coating, which preferably increases the sealing effect of the blade. Abrasion resistance and heat resistance.

Description

A high temperature resistant fan

technical field

The invention belongs to the technical field of light fans, and in particular relates to a high-temperature-resistant shut-off fan.

Background technique

The closing fan is divided into three categories: ordinary type, pressure-resistant type and high-temperature resistant type. The closing fan is an important equipment in the pneumatic conveying and ventilation and dust removal network. Its main function is to continuously discharge the materials in the unloader or dust collector in a timely manner. , while ensuring that the pressure inside the equipment is not exposed to atmospheric pressure. The air shutoff device is widely used in the pneumatic transportation of equipment in the fields of rice milling, flour milling, feed, machinery and chemical industry, medicine, tobacco, metallurgy, cement and dust removal, as well as the discharge of pipe network pressure state. When the fan is turned off and used at high temperature, such as in the production of extruded submerged materials, since the temperature of the extruded material after ejection can reach 150 degrees Celsius, the moisture content is as high as 30%, and the material characteristics are high temperature and high humidity. Features are completely different. Another example is that the temperature of some materials is as high as 600 degrees Celsius when they are just made. Under such production conditions, the conventional fan will have problems such as blade deformation, material jamming or serious air leakage, and large air leakage in actual use. . Fan blades and fan casings are generally made of carbon structural steel. In high temperature applications, deformation, slump and wear will inevitably occur. At the same time, the surface of carbon structural steel will produce oxides and cause pitting corrosion. These failure modes will lead to steel The surface is the first to fail or even break suddenly. Therefore, the necessary surface strengthening measures for carbon steel can improve the high temperature resistance and wear resistance of the steel surface, and can also greatly reduce the production cost of the enterprise and obtain good economic benefits.

SUMMARY OF THE INVENTION

In order to overcome the technical defects in the prior art, the present invention provides a high-temperature-resistant shut-off fan, which will not affect the sealing performance or cause the stuck phenomenon due to the high-temperature expansion or even deformation of the blades at higher temperatures.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A high-temperature-resistant shut-off fan, comprising:

a casing, the inner ring wall of the casing is provided with a plurality of guide grooves perpendicular to the axial direction along its axial direction, and the two sides of the casing are respectively provided with an inlet and an outlet that communicate with the inside of the casing;

A rotating shaft, the rotating shaft is axially threaded into the casing, and a plurality of blades along the axial direction of the rotating shaft are spaced around the rotating shaft. teeth; the blade surface is covered with a Ni60-WC laser cladding coating, and Ni60:WC=(9±0.5):1 (mass ratio) in the Ni60-WC laser cladding coating.

Further, the Ni60-WC laser cladding coating is obtained by the following method:

Step 1. Configure laser cladding powder

Mix according to mass ratio Ni60:WC=9:1, and the mixed powder is ball-milled in a ball mill for at least 2 hours to obtain composite powder;

Step 2. Preset powder

After the composite powder after ball milling in step 1 is taken out and dried, the mixed powder is fully mixed with a polyvinyl alcohol organic binder with a mass concentration of 3% to form a paste, which is evenly smeared on the pretreated surface. On the leaves, the thickness of the preset layer is 0.9-1mm, the surface is flattened, dried, and ready for use;

Step 3. Ni60+WC composite coating prepared by laser cladding

Put the dried blade on the laser platform, set the laser process parameters to 1.6KW, the scanning speed to 420mm/min, the defocus amount: 55mm, the protective gas flow rate: 8L·h-1, and finally make a laser on the surface of the blade. A Ni60-WC laser cladding coating was obtained.

The two ends of the casing are respectively provided with installation openings, the outer edge of the installation opening is provided with annular bosses around the circumference, the installation openings are provided with bearing seats, the bearing seats are installed through the annular bosses, and the two ends of the rotating shaft are rotated through the bearings It is installed on the bearing seat, and the shaft is coaxial with the casing.

Further, in order to facilitate the disassembly and replacement of the blades, the outer wall of the rotating shaft is spaced around the circumference with a plurality of dovetail grooves in the axial direction, and the blades can enter the interior of the casing through the installation openings at both ends of the casing and be clamped through the dovetail grooves. on the reels.

Compared with the prior art, the technical effect achieved by the present invention is: the protruding teeth designed on the edge of the fan blade, and the guiding grooves matched with the blade protruding teeth designed on the inner wall of the fan casing, when the fan blade rotates It will be fixed in a certain position by the guide groove to rotate. This design can greatly improve the sealing performance of the fan, and can achieve better sealing effect at high temperature; the surface of the fan blade is formed by laser cladding Ni60-WC The laser cladding coating improves the wear resistance and heat resistance of the blade.

Description of drawings

FIG. 1 is a schematic structural diagram of a fan shut-off in an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a fan shut-off casing in an embodiment of the present invention.

FIG. 3 is a top view of FIG. 2 .

FIG. 4 is a schematic diagram of the assembly of the fan blade and the rotating shaft in the embodiment of the present invention.

FIG. 5 is a right side view of FIG. 4 .

6 is the wear curve after high temperature friction and wear of the Ni60-WC laser cladding coating with Ni60:WC=9:1 formed on the blade surface in the embodiment of the present invention;

7 is a wear curve after high temperature friction and wear of the Ni60-WC laser cladding coating with Ni60:WC=4:1 formed on the blade surface in the embodiment of the present invention.

8 is a wear curve after high temperature friction and wear of the Ni60-WC laser cladding coating with Ni60:WC=7:3 formed on the blade surface in an embodiment of the present invention.

9 is a 50-times magnified electron microscope photo of the Ni60-WC laser cladding coating with Ni60:WC=9:1 formed on the blade surface before and after high temperature friction and wear in the embodiment of the present invention, wherein a is before wear, and b is wear back.

Fig. 10 is a 50 times magnified electron microscope photo of the Ni60-WC laser cladding coating with Ni60:WC=4:1 formed on the blade surface before and after high temperature friction and wear in the embodiment of the present invention, wherein a is before wear, and b is wear back.

11 is a 50-times magnified electron microscope photo of the Ni60-WC laser cladding coating with Ni60:WC=7:3 formed on the blade surface before and after high temperature friction and wear in the embodiment of the present invention, wherein a is before wear, and b is wear back.

The reference signs in the figure are: 1. casing, 2. guide groove, 3. inlet, 4. outlet, 5. rotating shaft, 6. blade, 7. convex teeth.

Detailed ways

The present invention is described in further detail below in conjunction with embodiment:

A high-temperature-resistant shut-off fan in this embodiment, as shown in Figures 1 to 4, includes a casing 1 and a rotating shaft 5,

The inner ring wall of the casing 1 is provided with a plurality of guide grooves 2 perpendicular to the axial direction along its axial direction. The rotating shaft 5 is axially rotated through the casing 1, and a plurality of blades 6 along the axial direction of the rotating shaft 5 are spaced around the rotating shaft 5. The blade 6 faces the inner wall of the casing 1. The convex teeth 7 of the blade 6; the surface of the blade 6 is covered with a Ni60-WC laser cladding coating, and in the Ni60-WC laser cladding coating, Ni60:WC=9:1, Ni60:WC=4:1, Ni60 :WC=7:3 mass ratio.

Specifically, two ends of the casing 1 are respectively provided with installation openings, the outer edge of the installation opening is provided with annular bosses around the circumference, the installation openings are provided with bearing seats, the bearing seats are installed through the annular bosses, and the two ends of the rotating shaft 5 pass through the bearings It is rotatably mounted on the bearing seat, and the rotating shaft 5 is coaxial with the casing.

The outer wall of the rotating shaft 5 is provided with a plurality of dovetail grooves in the axial direction spaced around the circumferential direction, and the blades 6 can enter the interior of the casing through the installation openings at both ends of the casing and be clamped on the rotating shaft 5 through the dovetail grooves (that is, for convenience. Blade installation, the distance between the side of the blade away from the installation shaft and the central axis of the rotating shaft is less than or equal to the radius of the installation opening), the base material of the blade 6 and the material of the casing 1 are Q235 steel.

An example of forming Ni60-WC laser cladding coating on the surface of blade 6 is as follows:

Example 1

1) Surface pretreatment of blade 6:

The surface of the blade 6 is polished with a 180# grinding wheel and then polished again by metallographic sandpaper to obtain a smooth and flat surface. After cleaning with alcohol, it is placed in a vacuum drying box to dry for use.

2) Configure laser cladding powder

Mixed according to the percentage Ni60:WC=9:1, the mixed powder was ball milled in a ball mill for 2 hours.

3) Preset powder

After the mixed composite powder is taken out and dried, the mixed powder is fully mixed with a polyvinyl alcohol organic binder with a mass concentration of 3% wt.% to form a paste, which is evenly spread on the surface of the treated blade 6 On the top, the thickness of the preset layer is 0.9-1mm, the surface is flattened, and finally dried in a drying box for use.

4) Ni60+WC composite coating prepared by laser cladding

Put the treated blade 6 on the platform of the laser, set the process parameters of the laser to 1.6KW, the scanning speed to 420mm/min, the defocus amount: 55mm, the protective gas flow rate: 8L·h ^-1 , and finally the percentage Ni60 is obtained. : Laser cladding coating with WC=9:1.

5) Use HT-1000 type screen display high temperature friction and wear testing machine, use ball-disk friction pair, the upper sample adopts _SiO2 friction ball, and the lower sample adopts Ni60/WC composite coating sample; the friction coefficient is used as friction and wear The performance index, the friction coefficient value is directly read by the testing machine.

6) Observe the surface of the cladding layer of the sample block under a 50x electron microscope

7) Use CMM to measure the flatness of the surface

8) After measurement, the composite cladding layer has fewer cracks, dense structure, and the coating thickness is 0.4-0.6mm. After the high temperature friction and wear test, the final friction coefficient is stable at about 0.2, and the worn surface has only shallow scratches. The amount of change in flatness is 0.002 mm.

Example 21) Surface pretreatment of blade 6:

The surface of the blade 6 is polished with a 180# grinding wheel and then polished again by metallographic sandpaper to obtain a smooth and flat surface. After cleaning with alcohol, it is placed in a vacuum drying box to dry for use.

2) Configure laser cladding powder

Mixed according to the percentage Ni60:WC=4:1, the mixed powder was ball milled in a ball mill for 2 hours.

3) Preset powder

After the mixed composite powder is taken out and dried, the mixed powder is fully mixed with a polyvinyl alcohol organic binder with a concentration of 3% wt.% to form a paste, which is evenly smeared on the surface of the treated Q235 steel , the thickness of the preset layer is 0.9-1mm, the surface is flattened, and finally dried in a drying box for use.

4) Ni60+WC composite coating prepared by laser cladding

Put the treated blade 6 on the laser platform, set the laser process parameters to 1.6KW, the scanning speed to 400mm/min, the defocus amount: 55mm, the protective gas flow rate: 8L·h ^-1 , and finally the percentage Ni60 is obtained. : Laser cladding coating with WC=4:1.

5) Use HT-1000 type screen display high temperature friction and wear testing machine, use ball-disk friction pair, the upper sample adopts _SiO2 friction ball, and the lower sample adopts Ni60/WC composite coating sample; the friction coefficient is used as friction and wear The performance index, the friction coefficient value is directly read by the testing machine.

6) Observe the surface of the cladding layer of the sample block under a 50x electron microscope

7) Use CMM to measure the flatness of the surface

8) After measurement, the composite cladding layer has visible pits, the coating thickness is 0.4-0.6mm, and the final friction coefficient is stable at about 0.3 after the high temperature friction and wear test, and the worn surface has visible cracks, pits, white spots, The amount of change in flatness is 0.005mm.

Example 3

1) Surface pretreatment of blade 6:

The surface of the blade 6 is polished with a 180# grinding wheel and then polished again by metallographic sandpaper to obtain a smooth and flat surface. After cleaning with alcohol, it is placed in a vacuum drying box to dry for use.

2) Configure laser cladding powder

Mixed according to the percentage Ni60:WC=7:3, the mixed powder was ball milled in a ball mill for 2 hours.

3) Preset powder

After the mixed composite powder is taken out and dried, the mixed powder is fully mixed with a polyvinyl alcohol organic binder with a concentration of 3% wt.% to form a paste, which is evenly smeared on the surface of the treated blade 6 , the thickness of the preset layer is 0.9-1mm, the surface is flattened, and finally dried in a drying box for use.

4) Ni60+WC composite coating prepared by laser cladding

Put the treated blade 6 on the platform of the laser, set the process parameters of the laser to 1.2KW, the scanning speed to 300mm/min, the defocus amount: 55mm, the protective gas flow rate: 8L·h ^-1 , and finally the percentage Ni60 is obtained. : Laser cladding coating with WC=7:3.

5) Use HT-1000 type screen display high temperature friction and wear testing machine, use ball-disk friction pair, the upper sample adopts _SiO2 friction ball, and the lower sample adopts Ni60/WC composite coating sample; the friction coefficient is used as friction and wear The performance index, the friction coefficient value is directly read by the testing machine.

6) Observe the surface of the cladding layer of the sample block under a 50x electron microscope

7) Use CMM to measure the flatness of the surface

8) After measurement, the composite cladding layer has many scratches and spots, and the coating thickness is 0.4-0.6mm. After the high temperature friction and wear test, the final friction coefficient is stable between 0.3-0.4, and the surface friction marks after wear are more serious. , the change in flatness is 0.007mm.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. Equivalent replacements or changes to its concept should be included within the protection scope of the present invention.

Claims (4)

1. a high temperature resistant type shut-off fan, is characterized in that: comprise: A casing (1), the inner ring wall of the casing (1) is provided with a plurality of guide grooves (2) perpendicular to the axial direction at intervals along the axial direction thereof, and two sides of the casing (1) are respectively provided There is an inlet (3) and an outlet (4) communicating with the inside of the casing (1); A rotating shaft (5), the rotating shaft (5) is rotatably inserted into the casing (1) in the axial direction, and a plurality of blades (6) along the axial direction of the rotating shaft (5) are arranged around the rotating shaft (5) at intervals, and the blades (6) The side facing the inner wall of the casing (1) is provided with protruding teeth (7) that guide and cooperate with the guide groove (2); the surface of the blade (6) is covered with a Ni60-WC laser cladding coating, and the Ni60-WC laser melting Ni60:WC=(9±0.5):1 (mass ratio) in the overcoat layer. 2. The high temperature resistant type shut-off fan according to claim 1, wherein the Ni60-WC laser cladding coating is obtained by the following method: Step 1. Configure laser cladding powder Mix according to mass ratio Ni60:WC=9:1, and the mixed powder is ball-milled in a ball mill for at least 2 hours to obtain composite powder; Step 2. Preset powder After the composite powder after ball milling in step 1 is taken out and dried, the mixed powder is fully mixed with a polyvinyl alcohol organic binder with a mass concentration of 3% to form a paste, which is evenly smeared on the pretreated surface. On the blade (6), the thickness of the preset layer is 0.9-1mm, the surface is flattened, dried, and ready for use; Step 3. Ni60+WC composite coating prepared by laser cladding Put the dried blade (6) on the platform of the laser, set the process parameters of the laser to 1.6KW, the scanning speed to 420mm/min, the defocus amount: 55mm, the protective gas flow rate: 8L·h-1, and finally A Ni60-WC laser cladding coating is prepared on the surface of the blade (6). 3. The high-temperature-resistant type shut-off fan according to claim 1, characterized in that: the two ends of the casing (1) are respectively provided with installation openings, and the outer edge of the installation opening is provided with an annular boss around the circumference, and the installation opening is provided with an annular boss. A bearing seat is provided, the bearing seat is installed through an annular boss, both ends of the rotating shaft (5) are rotatably installed on the bearing seat through bearings, and the rotating shaft (5) is coaxial with the casing. 4. The high-temperature-resistant closed fan according to claim 3, characterized in that: the outer wall of the rotating shaft (5) is provided with a plurality of dovetail grooves along the axial direction spaced around the circumference, and the blades (6) can be It enters the interior of the casing through the installation openings at both ends of the casing, and is clamped on the rotating shaft (5) through the dovetail slot.

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