Hexavalent chromium powdery reducing agent feeding device for cement production

Abstract

The utility model relates to the technical field of environment-friendly cement production, and discloses a hexavalent chromium powdery reducing agent feeding device for cement production, which comprises a ball mill, and a raw material hopper is arranged above an inlet of the ball mill; a wind turbine is mounted at one end of the wind conveying pipe, and the other end of the wind conveying pipe is connected to the feeding end of the powder concentrator; the discharge end of the ball mill is communicated with the pneumatic conveying pipe; the joint of a material pipe at the bottom of the reducing agent bin and the pneumatic conveying pipe is located between the discharging end of the ball mill and the feeding end of the powder concentrator; and a fine powder discharge port of the powder concentrator is connected to a cement bunker. The mixing of the reducing agent and the cement powder is mainly carried out in the pneumatic conveying pipe and the powder concentrator, especially in the pneumatic conveying pipe, so that the problem that the reducing agent is oxidized due to overhigh temperature in the process of directly introducing the reducing agent into the ball mill and grinding the reducing agent together with cement clinker or a mixture can be avoided; and it is ensured that the reducing agent has higher reducibility and can effectively reduce hexavalent chromium in cement.

Description

Technical Field

[0001] The utility model relates to the technical field of environmentally friendly cement production, in particular to a hexavalent chromium powder reducing agent feeding device for cement production. Background Art

[0002] Most of the existing hexavalent chromium reducing agents for cement are added before cement ball milling. At this time, they need to withstand high temperatures of more than 150-200°C in the cement mill, and certain requirements are placed on the stability of the reducing agent. Most reducing agents are easily oxidized by oxygen in the air under the high-temperature operating environment of the ball mill, thereby reducing their reducing properties during the use of cement, which is not conducive to the reduction of hexavalent chromium in cement and has a huge impact on the environment and ecology in the future. Summary of the invention

[0003] The purpose of the utility model is to provide a hexavalent chromium powder reducing agent feeding device for cement production. The mixing of the reducing agent and cement powder is mainly carried out in a pneumatic conveying pipe and a powder classifier, especially in the pneumatic conveying pipe, which can avoid the problem of the reducing agent being oxidized by excessively high temperature during the grinding process of the reducing agent and cement clinker or mixed material directly introduced into the ball mill, thereby ensuring that the reducing agent has stronger reducing property and can effectively reduce the hexavalent chromium in cement.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0005] A hexavalent chromium powdered reducing agent feeding device for cement production comprises a ball mill for cement grinding, wherein a raw material hopper is arranged above the inlet of the ball mill, and the bottom of the raw material hopper is connected to the feeding end of the ball mill through a material pipe; further comprising a wind conveying pipe and a reducing agent silo, wherein a wind turbine is installed at one end of the wind conveying pipe, and the other end is connected to the feeding end of a powder selector; the discharging end of the ball mill is connected to the wind conveying pipe; the reducing agent silo is located above the wind conveying pipe, and the bottom of the reducing agent silo is connected to the wind conveying pipe through the material pipe; the connection between the material pipe at the bottom of the reducing agent silo and the wind conveying pipe is located between the discharging end of the ball mill and the feeding end of the powder selector; and the fine powder discharging port of the powder selector is connected to a cement storage.

[0006] Furthermore, the coarse powder discharge port of the powder selector is connected to the feed end of the ball mill through a material pipe.

[0007] Furthermore, the feed end of the ball mill is also connected to a grinding aid silo through a feed pipe.

[0008] Furthermore, regulating valves are provided on the material pipes of the grinding aid material bin and the reducing agent material bin.

[0009] Furthermore, a pre-crushing mechanism is provided at the bottom of the raw material hopper, and the pre-crushing mechanism includes a shell, the top of the shell is connected to the bottom of the raw material hopper, and the bottom of the shell is connected to the feed end of the ball mill through a material pipe; two crushing rollers arranged opposite and parallel to each other are also installed in the shell, and the two crushing rollers are driven to rotate by a motor.

[0010] Compared with the prior art, the utility model has the following advantages: in the utility model, the mixing of the reducing agent and cement powder is mainly carried out in the pneumatic conveying pipe and the powder classifier, especially in the pneumatic conveying pipe, which can avoid the problem that the reducing agent is directly introduced into the ball mill and the temperature is too high during the grinding process together with the cement clinker or the mixed material, so that the reducing agent is oxidized, thereby ensuring that the reducing agent has stronger reducing property and can effectively reduce the hexavalent chromium in the cement. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0012] Figure 1 This is a schematic structural diagram of a hexavalent chromium powder reducing agent feeding device for cement production in this embodiment;

[0013] Among them: 1. ball mill; 2. raw material hopper; 3. wind conveying pipe; 4. reducing agent silo; 5. wind turbine; 6. powder classifier; 7. fine powder discharge port; 8. coarse powder discharge port; 9. grinding aid silo; 10. regulating valve; 11. shell; 12. crushing roller. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0015] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0016] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0017] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0018] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0019] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0020] like Figure 1 As shown, a hexavalent chromium powdered reducing agent feeding device for cement production includes a ball mill 1 for cement grinding, a raw material hopper 2 is arranged above the inlet of the ball mill 1, and the bottom of the raw material hopper 2 is connected to the feeding end of the ball mill 1 through a material pipe; it also includes a wind conveying pipe 3 and a reducing agent silo 4, one end of the wind conveying pipe 3 is installed with a wind turbine 5, and the other end of the wind conveying pipe 3 is connected to the feeding end of a powder selector 6; the discharge end of the ball mill 1 is connected to the wind conveying pipe 3; the reducing agent silo 4 is located above the wind conveying pipe 3, and the bottom of the reducing agent silo 4 is connected to the wind conveying pipe 3 through a material pipe; the connection between the material pipe at the bottom of the reducing agent silo 4 and the wind conveying pipe 3 is located between the discharge end of the ball mill 1 and the feeding end of the powder selector 6; the fine powder discharge port 7 of the powder selector 6 is connected to the cement storage.

[0021] like Figure 1As shown, in this embodiment, cement clinker and other mixed materials are continuously conveyed to the raw material hopper 2 after batching, and are conveyed to the ball mill 1 through the material pipe at the bottom of the raw material hopper 2; cement clinker and other mixed materials are ground and mixed evenly in the ball mill 1, and discharged from the discharge end to the wind conveying pipe 3; in the wind conveying pipe 3, the wind turbine 5 continuously supplies air, and the materials at the discharge end of the ball mill 1 and the reducing agent in the reducing agent silo 4 enter the wind conveying pipe 3 and are then conveyed to the powder selector 6 by wind; the ground cement powder and the reducing agent are fully mixed in the wind conveying pipe 3 and the powder selector 6; the powder selector 6 conveys the material with the fineness of composite cement to the fine powder discharge port 7, and then transports it to the cement warehouse for storage, and then carries out subsequent canning or packaging. The mixing of the reducing agent and cement powder in this embodiment is mainly carried out in the pneumatic conveying pipe 3 and the powder selector 6, especially in the pneumatic conveying pipe 3, which can avoid the problem of the reducing agent being oxidized by excessively high temperature during the grinding process of the reducing agent and cement clinker or mixed material when the reducing agent is directly introduced into the ball mill 1, thereby ensuring that the reducing agent has stronger reducing properties and can effectively reduce the hexavalent chromium in the cement.

[0022] Specifically, in order to prevent the airflow from entering the ball mill 1 from the discharge end of the ball mill 1 and causing the material to flow in the opposite direction, the discharge end of the ball mill 1 is tilted along the airflow conveying direction of the wind conveying pipe 3 in this embodiment.

[0023] like Figure 1 As shown, the coarse powder discharge port 8 of the powder selector 6 is connected to the feed end of the ball mill 1 through a material pipe. The coarse powder discharge port 8 of the powder selector 6 in this embodiment is connected to the feed end of the ball mill 1. After the reducing agent and cement are mixed in the wind conveying pipe 3 and the powder selector 6, the coarser powder screened out in the coarse powder discharge port 8 also contains a small amount of reducing agent. When the coarse powder is passed into the ball mill 1, not only the cyclic grinding of cement can be achieved, but also a small amount of reducing agent can be contained in the ball mill 1, and the cement powder can be pre-mixed with a small amount of reducing agent in the ball mill 1, ensuring that the reducing agent is fully in contact with the cement powder, improving the reducing effect of the reducing agent on hexavalent chromium in cement, and making full use of the reducing agent to reduce the waste caused by direct discharge of the reducing agent.

[0024] like Figure 1 As shown, the feed end of the ball mill 1 is also connected to the grinding aid silo 9 through a material pipe. The grinding aid silo 9 introduces an appropriate amount of grinding aid into the ball mill 1, which can significantly improve the grinding efficiency or reduce energy consumption. A regulating valve 10 is provided on the material pipes of the grinding aid silo 9 and the reducing agent silo 4. The grinding aid needs to be controlled in an appropriate amount during cement grinding, and the amount of reducing agent added should also be controlled within an appropriate range during the mixing of reducing agent and cement. In this embodiment, the amount of grinding aid or reducing agent added is controlled by the regulating valve 10.

[0025] like Figure 1As shown, the bottom of the raw material hopper 2 in this embodiment is provided with a pre-crushing mechanism, which includes a shell 11, the top of the shell 11 is connected to the bottom of the raw material hopper 2, and the bottom of the shell 11 is connected to the feed end of the ball mill 1 through a material pipe; two crushing rollers 12 are also installed in the shell 11 and are arranged in parallel to each other, and the two crushing rollers 12 are driven to rotate by a motor. In particular, before the cement clinker enters the ball mill 1, the two crushing rollers 12 of the pre-crushing mechanism can rotate in opposite directions to achieve the crushing of the cement clinker, ensuring that the cement clinker can be efficiently ground in the ball mill 1, so that the cement powder is mixed evenly, and can also be fully mixed evenly with the subsequent reducing agent, further ensuring the reducing effect of the reducing agent on hexavalent chromium in the cement.

[0026] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hexavalent chromium powder reducing agent feeding device for cement production, comprising a ball mill (1) for cement grinding, characterized in that: A raw material hopper (2) is arranged above the inlet of the ball mill (1), and the bottom of the raw material hopper (2) is connected to the feed end of the ball mill (1) through a material pipe; it also includes a wind conveying pipe (3) and a reducing agent silo (4), one end of the wind conveying pipe (3) is equipped with a wind turbine (5), and the other end of the wind conveying pipe (3) is connected to the feed end of a powder selector (6); the discharge end of the ball mill (1) is connected to the wind conveying pipe (3); the reducing agent silo (4) is located above the wind conveying pipe (3), and the bottom of the reducing agent silo (4) is connected to the wind conveying pipe (3) through a material pipe; the connection between the material pipe at the bottom of the reducing agent silo (4) and the wind conveying pipe (3) is located between the discharge end of the ball mill (1) and the feed end of the powder selector (6); the fine powder discharge port (7) of the powder selector (6) is connected to the cement storage.

2. A hexavalent chromium powder reducing agent feeding device for cement production according to claim 1, characterized in that: The coarse powder discharge port (8) of the powder selector (6) is connected to the feed end of the ball mill (1) through a feed pipe.

3. A hexavalent chromium powder reducing agent feeding device for cement production according to claim 1, characterized in that: The feed end of the ball mill (1) is also connected to a grinding aid silo (9) via a feed pipe.

4. A hexavalent chromium powder reducing agent feeding device for cement production according to claim 3, characterized in that: The material pipes of the grinding aid material bin (9) and the reducing agent material bin (4) are both provided with regulating valves (10).

5. A hexavalent chromium powder reducing agent feeding device for cement production according to any one of claims 1 to 4, characterized in that: A pre-crushing mechanism is arranged at the bottom of the raw material hopper (2), and the pre-crushing mechanism comprises a shell (11), the top of the shell (11) is connected to the bottom of the raw material hopper (2), and the bottom of the shell (11) is connected to the feed end of the ball mill (1) through a material pipe; two crushing rollers (12) arranged opposite to each other and parallel to each other are also installed in the shell (11), and the two crushing rollers (12) are driven to rotate by a motor.

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