Fan for wet-process phosphoric acid extraction tail gas

Abstract

The fan for wet-process phosphoric acid extraction tail gas comprises an impeller and a machine shell arranged on the outer side of the impeller, the impeller comprises a rear disc, a shaft disc is installed in the center of the rear disc through rivets, the shaft disc is in key connection with a fan shaft driven by a motor, a flat-plate-shaped front disc is arranged on the front side of the rear disc, a hole is formed in the center of the front disc, and an impeller ring is welded to the center of the front disc. A plurality of straight blades are welded between the front disc and the rear disc, the blades surround the center of the rear disc and are obliquely arranged at an angle with the radial direction, and the rear disc, the front disc, the impeller ring and the blades are all made of HASTELLOY B-3 steel plates. The impeller main body adopts a chloride ion corrosion resistant steel plate, so that the service life is obviously prolonged; the front disc is arranged to be in a flat plate shape, sharp corners in the impeller are reduced, the surface of the impeller is smooth and smooth, and material stress concentration caused by material bending is avoided. The blades are arranged to be in an inclined straight shape forming a certain angle with the radial direction, and compared with arc blades, the scaling speed and the unbalance tendency of the impeller are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of phosphate fertilizer processing technology, especially to a fan for wet-process phosphoric acid extraction tail gas. BACKGROUND

[0002] In the extraction section of the wet-process phosphoric acid process in the phosphate fertilizer industry, the extraction fan functions to lead part of the water vapor and non-condensable gas generated in the extraction tank to the exhaust cylinder after purification equipment for discharge.

[0003] The fan shell and impeller are generally made of carbon steel for corrosion prevention, and the gas is corrosive, so the fan, especially the impeller, generally has the problems of short service life and frequent maintenance; some glass steel fans are used, which have low material strength and are prone to breakage and fatigue failure.

[0004] Phosphate salts of potassium, sodium, calcium, etc. and fluorosilicate exist in the extraction tail gas, and as the gas is transported in the glass steel pipeline, the temperature drops from 85-90℃ to 40-60℃, and these metal salts are cooled and crystallized, causing the impeller of the fan to scale and the impeller to be unbalanced, causing the fan to vibrate and the fan impeller to corrode more severely. SUMMARY

[0005] To solve the above problems in the prior art, the utility model provides a fan for wet-process phosphoric acid extraction tail gas.

[0006] The utility model provides a fan for wet-process phosphoric acid extraction tail gas adopts the following technical scheme:

[0007] A fan for wet-process phosphoric acid extraction tail gas, comprising an impeller and a shell arranged on the outside of the impeller, the impeller comprising a rear disc, a shaft disc being installed at the center of the rear disc by rivets, a fan shaft being connected to the shaft disc by keys and being driven by a motor, a flat plate-shaped front disc being arranged on the front side of the rear disc, a hole being formed in the center of the front disc and a ring being welded to the hole, a plurality of flat blades being welded between the front disc and the rear disc, the blades being arranged around the center of the rear disc and being arranged at an angle with respect to the radial direction, and the rear disc, the front disc, the ring and the blades being made of HASTELLOY B-3 steel plates.

[0008] By adopting the above technical scheme, the impeller body is made of HASTELLOY B-3 steel plates which are resistant to chloride ion corrosion and have excellent stress corrosion resistance, significantly improving the service life; the front disc is arranged in a flat plate shape, reducing the sharp corners in the impeller, making the surface of the impeller smooth and smooth, and avoiding material stress concentration caused by material bending; the blades are arranged in a flat shape at an angle with respect to the radial direction, which reduces the scaling speed and unbalanced tendency of the impeller compared with circular arc blades.

[0009] Optionally, the shell is fixedly installed on the foundation by ear plates and foundation bolts.

[0010] Through the above technical scheme, the ear plate and the anchor bolt are used in cooperation, and the convenience of mounting or dismounting the elevator shell is facilitated.

[0011] Optionally, an air inlet cylinder is arranged in front of the impeller, the air inlet cylinder is trumpet-shaped, and the end with a smaller opening is inserted into the ring, the outer wall of the air inlet cylinder is welded with a mounting plate, and the mounting plate is mounted on the end face of the shell through connecting screws.

[0012] Through the above technical scheme, the air inlet cylinder effectively collects air and is convenient for connection with other pipelines.

[0013] Optionally, a plurality of rib plates are welded between the mounting plate and the air inlet cylinder, and the rib plates are evenly arranged around the air inlet cylinder.

[0014] Through the above technical scheme, the setting of the rib plate improves the stability of the air inlet cylinder during work.

[0015] Optionally, the end with a larger opening of the air inlet cylinder is welded with an outwardly protruding and annular cornice.

[0016] Through the above technical scheme, the cornice and the bolt can be used to conveniently connect the air inlet pipeline.

[0017] Optionally, the motor is adapted to be mounted with a frequency converter.

[0018] Through the above technical scheme, the characteristic parameters of the fan are adapted to the characteristics of the on-site pipeline, when the air volume and air pressure change, the frequency of the frequency converter is adjusted, the rotating speed of the fan is adjusted, the fatigue limit time of the impeller and other materials is prolonged, and the service life is improved.

[0019] Optionally, the fan shaft is made of duplex stainless steel 2205.

[0020] Through the above technical scheme, the fan shaft made of duplex stainless steel 2205 has the advantages of corrosion resistance, high strength, good machining performance and the like.

[0021] Optionally, the shell is made of S31603 steel material and internally provided with a rubber corrosion-resistant layer.

[0022] Through the above technical scheme, the shell outside is effectively prevented from rusting in a corrosive environment.

[0023] In summary, the utility model has at least one of the following beneficial technical effects:

[0024] The impeller body is made of HASTELLOY B-3 steel plate which is resistant to chloride ion corrosion and has excellent stress corrosion resistance, and the service life is significantly improved;

[0025] The front disc is provided in a flat plate shape, sharp corners in the impeller are reduced, the surface of the impeller is smooth and smooth, and material stress concentration caused by material bending is avoided;

[0026] The blade is arranged in a slanting flat shape at an angle to the radial direction, and compared with a circular arc blade, the fouling speed and unbalance tendency of the impeller are reduced. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a structural schematic view of the fan for wet-process phosphoric acid extraction tail gas according to the embodiment of the present application.

[0028] Figure 2 It is a side view of the impeller structure according to the embodiment of the present application.

[0029] Figure 3 It is a front view of the impeller structure according to the embodiment of the present application.

[0030] The reference signs are explained as follows: 1, base; 2, motor; 3, shaft coupling; 4, fan shaft; 5, bearing seat; 6, impeller; 60, rear disc; 61, shaft disc; 62, rivet; 63, front disc; 64, mouth ring; 65, blade; 7, casing; 70, ear plate; 71, anchor bolt; 8, air inlet cylinder; 80, mounting plate; 81, connecting screw; 82, rib plate; 83, eaves. DETAILED DESCRIPTION

[0031] The following will be explained in combination with the accompanying drawings. Figure 1 - the accompanying drawings Figure 3 The present application will be further explained in detail.

[0032] The embodiment of the present application discloses a fan for wet-process phosphoric acid extraction tail gas. Referring to Figure 1 , the fan for wet-process phosphoric acid extraction tail gas comprises a base 1, a motor 2, a shaft coupling 3, a fan shaft 4, a bearing seat 5, an impeller 6, a casing 7 and an air inlet cylinder 8. The motor 2 is used in cooperation with a frequency converter, so that the characteristic parameters of the fan are suitable for the characteristics of the on-site pipeline. When the air volume and air pressure change, the frequency of the frequency converter is adjusted, the rotating speed of the fan is adjusted, the fatigue limit time of the materials such as the impeller 6 is prolonged, and the service life thereof is improved.

[0033] Referring to Figure 1 , the motor 2 and the bearing seat 5 are fixedly installed on the base 1, the fan shaft 4 is connected with the output shaft of the motor 2 through the shaft coupling 3, the fan shaft 4 is installed through the bearing seat 5 and the end portion thereof is connected with the impeller 6, the fan shaft 4 is made of duplex stainless steel 2205, and has the advantages of corrosion resistance, high strength and good machining performance. The casing 7 is installed on the outer side of the impeller 6 and is fixed on the base 1 through the ear plate 70 and the anchor bolt 71, the casing 7 is made of S31603 steel material, so that the external part of the casing 7 is prevented from rusting in a corrosive environment, and a rubber corrosion-proof layer is arranged in the internal part of the casing 7.

[0034] Referring to Figure 2 and Figure 3, the impeller 6 includes a rear disc 60, the rear disc 60 is centrally perforated and is inserted with a shaft disc 61 from rear to front, the shaft disc 61 is fixed on the rear disc 60 by rivets 62, the shaft disc 61 is keyed connected with the fan shaft 4, the rear disc 60 is provided with a front disc 63 in parallel on the front side, the front disc 63 is centrally perforated and is vertically welded with a ring 64 around the perforation, the front disc 63 is flat, a plurality of flat blades 65 are welded and fixed between the front disc 63 and the rear disc 60, the blades 65 are circumferentially arranged around the center of the rear disc 60 and are obliquely arranged at a certain angle with the radial direction.

[0035] The rear disc 60, the front disc 63, the ring 64 and the blades 65 are welded by HASTELLOY B-3 steel plates, the HASTELLOY B-3 steel plates have the advantages of resistance to chloride ion corrosion, excellent stress corrosion resistance, good strength, high hardness, smooth surface and the like, the shaft disc 61 is cast and processed by ZG270-500 steel material, and the shaft disc 61 is riveted and fixed with the rear disc 60 by the rivets 62 made of S31603 steel material.

[0036] Referring to Figure 1 The air inlet cylinder 8 is inserted into the ring 64 at the end with a small opening in a trumpet shape, the air inlet cylinder 8 is welded with a mounting plate 80 on the outer wall, the mounting plate 80 is connected with the end face of the casing 7 through connecting screws 81, a plurality of rib plates 82 for reinforcement are further welded between the mounting plate 80 and the outer wall of the air inlet cylinder 8, the rib plates 82 are evenly arranged around the air inlet cylinder 8, the air inlet cylinder 8 is welded with a outwardly protruding and annular cornice 83 at the end with a large opening, and the air inlet pipeline can be connected through the cornice 83.

[0037] The fan for wet-process phosphoric acid extraction tail gas in the embodiment of the utility model, the main body of the impeller 6 is made of HASTELLOY B-3 steel plate with resistance to chloride ion corrosion and excellent stress corrosion resistance, so that the service life is significantly improved, the front disc 63 is arranged in a flat shape, so that the sharp corners in the impeller 6 are reduced, the surface of the impeller 6 is smooth and smooth, and material stress concentration caused by material bending is avoided, the blades 65 are arranged in a flat shape at a certain angle with the radial direction, compared with the circular arc blades, the fouling speed and the unbalance tendency of the impeller 6 are reduced.

[0038] The above are preferred embodiments of the utility model, and do not limit the protection scope of the utility model, so that: equivalent changes made according to the structure, shape and principle of the utility model should be covered in the protection scope of the utility model.

Claims

1. A fan for wet-process phosphoric acid extraction off-gas, characterized by: The impeller (6) comprises a rear disc (60), the shaft disc (61) is installed at the center of the rear disc (60) through a rivet (62), the fan shaft (4) driven by the motor (2) is connected to the shaft disc (61) through a key, the front disc (63) in a flat plate shape is arranged at the front side of the rear disc (60), the front disc (63) is provided with a hole at the center and is welded with a ring (64), a plurality of flat blades (65) are welded between the front disc (63) and the rear disc (60), the blades (65) are arranged at an angle with the radial direction and surround the center of the rear disc (60), the rear disc (60), the front disc (63), the ring (64) and the blades (65) are all made of HASTELLOY B-3 steel plate.

2. The fan for wet-process phosphoric acid extraction off-gas according to claim 1, characterized in that: The machine shell (7) is fixedly installed on the base (1) through the lug plate (70) and the anchor bolt (71).

3. The fan for wet-process phosphoric acid extraction off-gas according to claim 1, characterized in that: The front of the impeller (6) is provided with the air inlet cylinder (8), the air inlet cylinder (8) is inserted into the ring (64) at the end with a small opening, the mounting plate (80) is welded to the outer wall of the air inlet cylinder (8), and the mounting plate (80) is installed on the end face of the machine shell (7) through the connecting screw (81).

4. The fan for wet-process phosphoric acid extraction off-gas according to claim 3, characterized in that: A plurality of rib plates (82) are welded between the mounting plate (80) and the air inlet cylinder (8), and the rib plates (82) are evenly arranged around the air inlet cylinder (8).

5. The fan for wet-process phosphoric acid tail gas according to claim 3 or 4, characterized in that: The end with a large opening of the air inlet cylinder (8) is welded with the outwardly protruding and annular cornice (83).

6. The fan for wet phosphoric acid extraction off-gas as claimed in claim 1 wherein: The motor (2) is adaptively installed with the frequency converter.

7. The fan for wet phosphoric acid extraction off-gas as claimed in claim 1 wherein: The fan shaft (4) is made of duplex stainless steel 2205.

8. The fan for wet phosphoric acid extraction off-gas as claimed in claim 1 wherein: The machine shell (7) is made of S31603 steel material and is internally provided with a rubber corrosion-resistant layer.

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