Aerodynamic defoaming device for flotation froth

Abstract

The utility model provides an aerodynamic defoaming device for flotation froth, and particularly relates to the technical field of defoaming of a coal flotation process. The device comprises a tank body and a plurality of jet pipes, an exhaust pipe is arranged at the top of the tank; a rotatable impeller is arranged at the position, close to the top, of the inner cavity of the tank body; the part, below the impeller, of the tank body adopts a double-layer tank wall structure; an upper fixing plate and a lower fixing plate which are parallel to each other are arranged in the middle of an inner cavity of the inner-layer tank wall, and the inner cavity of the inner-layer tank wall is divided into an upper cavity, a distribution cavity and a lower cavity by the two fixing plates; the plurality of jet pipes are distributed between the two fixing plates; a feeding pipe, an air inlet pipe and an auxiliary exhaust pipe are arranged on the outer side wall of the tank body; a drain pipe is arranged at the bottom of the tank body. The three-phase foam breaking device is simple and reasonable in structure, solid-liquid-gas three-phase foam can be effectively broken in combination with the Venturi principle, secondary foam caused by discharge is avoided, and meanwhile the situation that treatment of the jet pipe is not timely due to the fact that the foam absorption amount is large is considered.

Description

Technical Field

[0001] This utility model relates to the field of defoaming technology in coal flotation process, specifically to a flotation foam aerodynamic defoaming device. Background Technology

[0002] Flotation is currently the most widely used, technologically mature, and effective method for separating fine coal slime, playing a crucial role in coal preparation production. However, due to various factors such as slurry properties, reagent reactions, and process equipment, a large amount of foam is generated during the flotation process. This foam is stable, highly viscous, and difficult to eliminate naturally. The foam flows into the concentrate bucket with the flotation concentrate, and the continuous accumulation of foam not only reduces the effective volume of the concentrate bucket but also easily leads to pump cavitation, affecting subsequent process feeding. In severe cases, foam overflow may occur, impacting production safety.

[0003] Currently, the commonly used defoaming methods in flotation processes both domestically and internationally include natural defoaming, chemical defoaming, and physical defoaming. However, all of them have the following problems: 1. Although natural defoaming is relatively inexpensive, it is time-consuming and often difficult to implement due to the limited area of ​​the well site; 2. Chemical defoaming can achieve rapid defoaming, but the use of defoaming agents not only increases production costs but also poses a certain degree of pollution; 3. Ultrasonic devices can achieve rapid defoaming, but the high price of ultrasonic devices greatly increases production costs.

[0004] Therefore, the difficulty in eliminating foam in clean coal during flotation has become one of the main problems in coal preparation production. There is an urgent need to develop defoaming technologies suitable for on-site use to improve defoaming efficiency and ensure production efficiency and safety. Utility Model Content

[0005] To overcome the shortcomings of the prior art, this utility model provides a flotation foam pneumatic defoaming device, the specific technical solution of which is as follows:

[0006] A flotation foam pneumatic defoaming device includes a tank and several jet pipes. An exhaust pipe is located at the top of the tank. A rotatable impeller is positioned within the inner cavity of the tank at a distance of 1 / 5 of the tank's height from the top. The portion of the tank below the impeller employs a double-wall structure, comprising an inner wall and an outer wall. The inner wall is a cylindrical structure with openings at the top and bottom. Two parallel fixing plates are positioned in the middle of the inner wall's cavity, dividing the inner cavity into an upper chamber, a distribution chamber, and a lower chamber. Several jet pipes are vertically and evenly distributed between the two fixing plates. A feed pipe communicating with the upper chamber is located on the outer wall of the tank, corresponding to the upper chamber and near the distribution chamber. An air inlet pipe communicating with the distribution chamber is located on the outer wall of the tank, corresponding to the distribution chamber. An auxiliary exhaust pipe communicating with the lower chamber is located on the outer wall of the tank, corresponding to the lower chamber and near the distribution chamber. A drain pipe is located at the bottom of the tank.

[0007] Preferably, the gap between the inner tank wall and the outer tank wall is 0.1 times the tank diameter.

[0008] Preferably, the impeller adopts a fully open structure, and the diameter of the impeller blades is 0.5 to 0.75 times the inner diameter of the outer tank wall; the bottom edge of the impeller shell is welded and sealed to the top inner side wall of the inner tank wall, and the top edge of the impeller shell is not sealed.

[0009] Preferably, the diameter of the feed pipe is 0.3 to 0.35 times the inner diameter of the outer tank wall.

[0010] Preferably, the outlet of the exhaust pipe is connected to a ventilator; the diameter of the exhaust pipe is 0.35 to 0.4 times the inner diameter of the outer tank wall.

[0011] Preferably, a plurality of the jet tubes are specifically disposed at an inner diameter of the outer tank wall, approximately 0.05 times the diameter of the feed pipe below the inner tank wall; the plurality of jet tubes are fixedly connected to the upper and lower fixing plates by welding.

[0012] Preferably, the inlets of the plurality of jet tubes are all connected to the upper chamber, and the outlets of the plurality of jet tubes are all connected to the lower chamber.

[0013] More preferably, the jet tube adopts a Venturi jet tube structure, including an air inlet, a constriction section, a throat, and a diffuser section;

[0014] More preferably, the diameter of the jet tube is 0.1 times the inner diameter of the outer tank wall, and the distance between every two jet tubes is 0.1 times the inner diameter of the outer tank wall.

[0015] More preferably, the drain pipe is equipped with an electric drain valve; the inner cavity of the lower chamber is also equipped with a liquid level sensor, and the liquid level sensor is electrically connected to the electric drain valve.

[0016] The beneficial effects of this utility model are:

[0017] This invention has a simple and reasonable structure. Combining the Venturi principle, it can effectively break up solid-liquid-gas three-phase foam and avoid the occurrence of secondary foam due to discharge. At the same time, it also takes into account the situation where the foam absorption volume is large and the jet tube is not timely. Attached Figure Description

[0018] The accompanying drawings constituting this application are provided to further understand this application and do not constitute an undue limitation of this application.

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a top view of the impeller in this utility model;

[0021] Figure 3 This is a cross-sectional view of the jet tube in this utility model;

[0022] Figure 4 This is a distribution diagram of the jet tubes in this utility model;

[0023] In the diagram, 1-exhaust pipe; 2-tank body; 3-impeller; 4-feed pipe; 5-upper chamber; 6-distribution chamber; 7-jet pipe; 8-air inlet pipe; 9-lower chamber; 10-auxiliary exhaust pipe; 11-drain pipe; 12-electric drain valve; 13-liquid level sensor; 14-fixed plate. Detailed Implementation

[0024] The specific implementation of the flotation foam pneumatic defoaming device provided by this utility model will be further described with reference to the accompanying drawings and embodiments.

[0025] like Figure 1As shown, a flotation foam pneumatic defoaming device includes a tank body 2 and several jet pipes 7. An exhaust pipe 1 is provided at the top of the tank body 2. Preferably, the outlet of the exhaust pipe 1 is connected to an exhaust fan, and the diameter of the exhaust pipe 1 is 0.35 to 0.4 times the diameter of the tank body. A rotatable impeller 3 is provided at a position 1 / 5 of the tank body height from the top of the tank. The portion of the tank body 2 below the impeller 3 adopts a double-wall structure, including an inner tank wall and an outer tank wall. Preferably, the inner tank wall is a cylindrical structure with openings at the top and bottom. Two parallel fixing plates 14 are provided in the middle of the inner cavity of the inner tank wall, dividing the inner cavity of the inner tank wall into an upper chamber 5, a distribution chamber 6, and a lower chamber 9. Several jet pipes 7 are vertically and evenly distributed between the two fixing plates 14. All jet pipes 7 are fixedly connected to the upper and lower fixing plates 14 by welding.

[0026] Preferably, the outer wall of the tank body 2 is provided with a feed pipe 4 that communicates with the upper chamber 5, corresponding to the position of the upper chamber 5 near the distribution chamber 6; wherein the diameter of the feed pipe 4 is 0.3 to 0.35 times the inner diameter of the outer tank wall.

[0027] Preferably, the outer wall of the tank 2 is provided with a high-pressure gas inlet pipe 8 that communicates with the distribution chamber 6 at a position corresponding to the distribution chamber 6;

[0028] Preferably, the outer wall of the tank body 2 is provided with an auxiliary exhaust pipe 10 that communicates with the lower chamber 9 at a position corresponding to the lower chamber 9 near the distribution chamber 6;

[0029] Preferably, a drain pipe 11 is provided at the bottom of the tank body 2; wherein an electric drain valve 12 is provided on the drain pipe 11; a liquid level sensor 13 is also provided in the inner cavity of the lower chamber 9. It is worth noting that the liquid level sensor 13 is electrically connected to the electric drain valve 12, and the liquid level sensor 13 detects the change in liquid level inside the tank body 2 and controls the opening degree and discharge amount of the electric drain valve 12.

[0030] More preferably, the gap between the inner tank wall and the outer tank wall is 0.1 times the inner diameter of the outer tank wall. The solid-liquid two-phase mixture, inertially ejected by the impeller 3, flows to the bottom of the tank body 2 and is then discharged. Preferably, the inner tank wall and the outer tank wall are fixed together by spot welding or by setting connection points to avoid affecting the flow.

[0031] like Figure 2 As shown, the impeller 3 adopts a fully open structure, wherein the blade diameter of the impeller 3 is 0.5 to 0.75 times the inner diameter of the outer tank wall. The bottom edge of the outer shell of the impeller 3 is welded and sealed to the top inner wall of the inner tank wall, while the top edge of the outer shell of the impeller 3 is not sealed.

[0032] More preferably, a plurality of jet pipes 7 are specifically disposed at a position within the inner cavity of the inner tank wall, approximately 0.05 times the inner diameter of the outer tank wall below the feed pipe 4. It is worth noting that the inlets of the plurality of jet pipes 7 are all connected to the upper chamber 5, and their outlets are all connected to the lower chamber 9.

[0033] like Figure 3 As shown, several jet tubes 7 adopt a Venturi jet tube structure, each including an air inlet, a constriction section, a throat, and a diffuser section. The working principle of the jet tube is as follows: after the fluid enters the jet tube from the inlet section, it accelerates through the constriction section, reaches its maximum speed and minimum pressure when passing through the throat, and then enters the diffuser section to decelerate and diffuse before finally being discharged.

[0034] like Figure 4 As shown, several jet tubes 7 have a diameter of 0.1 times the inner diameter of the outer tank wall, and are evenly distributed between two fixed plates 14 at equal intervals, with the spacing between every two jet tubes 7 being 0.1 times the inner diameter of the outer tank wall.

[0035] In operation, high-pressure gas is first introduced into the air inlet of the jet pipe 7 in the distribution chamber 6 through the air inlet pipe 8. After entering the jet pipe 7, the high-pressure gas is discharged from the outlet of the jet pipe 7 into the lower chamber 9 under the action of the Venturi principle, which will then form a vacuum negative pressure at the inlet end of the jet pipe 7. The inlet end of the jet pipe 7 is connected to the upper chamber 5, and a vacuum negative pressure is formed in the upper chamber 5. At the same time, the exhaust fan draws air out from the top of the exhaust pipe 1. Under the dual suction action of the vacuum negative pressure and the exhaust fan, the upper chamber 5 forms a stronger vacuum pressure, which in turn enables the impeller 3 to rotate at high speed and form sufficient suction at the inlet of the feed pipe 4 of the upper chamber 5, so that the external solid-liquid-gas three-phase foam can automatically enter the upper chamber 5 tangentially from the feed pipe 4. Under the action of strong turbulence at the inlet of the jet pipe 7, the first defoaming is completed.

[0036] Then, the broken gas moves upward and is discharged from the exhaust pipe 1 through the impeller 3. The solid-liquid two-phase mixture remaining after the first defoaming and the small foam formed after breaking are re-entered into the jet pipe 7 under the dual action of gravity and negative pressure suction of the jet pipe 7. Under the impact of the high-speed airflow in the jet pipe 7, the foam is completely broken.

[0037] Next, the crushed solid-liquid two-phase mixture enters the lower chamber 9 from the outlet of the jet pipe 7 for temporary storage. It is worth noting that the high-pressure gas entering the lower chamber 9 needs to be discharged from the auxiliary exhaust pipe 10 of the lower chamber 9 after the pressure is released. The solid-liquid two-phase mixture temporarily stored in the lower chamber 9 is discharged intermittently. That is, when the liquid level in the lower chamber 9 reaches the height set by the liquid level sensor 13, the electric drain valve 12 automatically opens to discharge the material. When the liquid level is lower than the set threshold of the liquid level sensor 13, the electric drain valve 12 automatically closes to prevent gas from entering the drain pipe 11 and forming secondary foam.

[0038] Finally, when the amount of foam absorbed is large, a small amount of foam in the upper chamber 5 will be splashed onto the impeller 3 by the wind force of the exhaust fan. Through the high-speed rotation and shearing action of the impeller 3, the foam is cut and broken. The broken gas moves upward and is discharged from the exhaust pipe 1. The broken solid-liquid two-phase mixture is thrown onto the inner wall of the outer tank wall under the action of inertia, and flows downward through the gap between the inner and outer tank walls to the bottom of the tank body 2 under the action of gravity, and then is discharged from the drain pipe 11.

[0039] This invention has a simple and reasonable structure. Combining the Venturi principle, it can effectively break up solid-liquid-gas three-phase foam and avoid the occurrence of secondary foam due to discharge. At the same time, it also takes into account the situation where the foam absorption volume is large and the jet tube is not timely.

[0040] In this utility model, terms such as "upper," "lower," "bottom," and "top" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are merely used to facilitate the description of the structural relationships of the various components or elements of this utility model and do not specifically refer to any part or element of this utility model; they should not be construed as limiting this utility model. Terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and they should not be construed as limiting this utility model.

[0041] Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present utility model should also fall within the protection scope of the present utility model.

Claims

1. A flotation foam pneumatic defoaming device, characterized in that, It includes a tank body and several jet pipes; an exhaust pipe is provided on the top of the tank body; a rotatable impeller is provided in the inner cavity of the tank body at a position 1 / 5 of the tank body height from the top of the tank body; The portion of the tank below the impeller adopts a double-wall structure, comprising an inner tank wall and an outer tank wall. The inner tank wall is a cylindrical structure with openings at the top and bottom. Two parallel fixing plates are provided in the middle of the inner cavity of the inner tank wall, which divide the inner cavity of the inner tank wall into an upper chamber, a distribution chamber, and a lower chamber. Several jet tubes are vertically and evenly distributed between two fixed plates; The outer wall of the tank is provided with a feed pipe that communicates with the upper chamber, corresponding to the position of the upper chamber near the distribution chamber; An air inlet pipe communicating with the distribution chamber is provided on the outer wall of the tank corresponding to the position of the distribution chamber; An auxiliary exhaust pipe communicating with the lower chamber is provided on the outer wall of the tank body at a position corresponding to the lower chamber near the distribution chamber; A drain pipe is installed at the bottom of the tank.

2. The flotation foam pneumatic defoaming device according to claim 1, characterized in that, The gap between the inner tank wall and the outer tank wall is 0.1 times the tank diameter.

3. The flotation foam pneumatic defoaming device according to claim 1, characterized in that, The impeller adopts a fully open structure, and the blade diameter of the impeller is 0.5 to 0.75 times the inner diameter of the outer tank wall; The bottom edge of the impeller's outer shell is welded and sealed to the top inner wall of the inner tank wall, while the top edge of the impeller's outer shell is not sealed.

4. The flotation foam pneumatic defoaming device according to claim 1, characterized in that, The diameter of the feed pipe is 0.3 to 0.35 times the inner diameter of the outer tank wall.

5. The flotation foam pneumatic defoaming device according to claim 1, characterized in that, The outlet of the exhaust pipe is connected to a ventilator; the diameter of the exhaust pipe is 0.35 to 0.4 times the inner diameter of the outer tank wall.

6. The flotation foam pneumatic defoaming device according to claim 1, characterized in that, Several of the jet tubes are specifically installed in the inner cavity of the inner tank wall, about 0.05 times the inner diameter of the outer tank wall below the feed pipe; Several jet tubes are fixedly connected to the upper and lower fixing plates by welding.

7. The flotation foam pneumatic defoaming device according to claim 6, characterized in that, The inlets of the jet tubes are all connected to the upper chamber, and the outlets of the jet tubes are all connected to the lower chamber.

8. The flotation foam pneumatic defoaming device according to claim 7, characterized in that, The jet tube adopts a Venturi jet tube structure, including an air inlet, a constriction section, a throat, and a diffuser section.

9. The flotation foam pneumatic defoaming device according to claim 8, characterized in that, The diameter of the jet tube is 0.1 times the inner diameter of the outer tank wall, and the distance between any two jet tubes is 0.1 times the inner diameter of the outer tank wall.

10. The flotation foam pneumatic defoaming device according to claim 1, characterized in that, The drain pipe is equipped with an electric drain valve; the lower chamber is also equipped with a liquid level sensor, and the liquid level sensor is electrically connected to the electric drain valve.

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