Rotary gas-phase white carbon black deacidification method and device

Abstract

The invention provides a rotary gas-phase white carbon black deacidification method and device. The device comprises a furnace body, a feeding assembly and a discharging assembly, and the furnace body is a rotary furnace body; the feeding assembly is arranged in front of the furnace body, the furnace body is connected with the feeding assembly through a bearing assembly, and the feeding assembly is further provided with an acid discharging opening used for discharging acid gas; the discharging assembly is arranged behind the furnace body, the furnace body is connected with the discharging assembly through a bearing assembly, the discharging assembly is further provided with a heat source feeding port used for introducing high-temperature gas, and the heat source feeding port is communicated with the furnace body and the acid discharging port. In the deacidification process, white carbon black moves in the furnace body in a rotary mode, hot air entering the furnace body through the heat source feeding port removes acid in the white carbon black and then is discharged through the acid discharging port, and due to the fact that the hot air enters the heat source feeding port, the pressure of the heat source feeding port is larger than that of the acid discharging port, acid gas obtained after deacidification can be discharged in an oriented mode; and the high-temperature gas is directly mixed with the white carbon black, so that the deacidification efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of deacidification of fumed silica, and in particular to a rotary deacidification method and device for fumed silica. Background Art

[0002] Fumed silica is widely used in rubber, plastic, coating, ink and cosmetic industries. However, HCl gas is often produced during the production process of fumed silica. If the acidic HCl gas is not treated, it will affect the performance of the product. Therefore, it is particularly important to effectively deacidify fumed silica.

[0003] At present, the deacidification equipment for gas phase silica generally adopts fixed electric heating equipment for addition. Because a large amount of silica flows as a whole during the flow of gas phase silica in the fixed equipment column, the silica in the inner layer will be wrapped by the silica in the outer layer, resulting in the inability to effectively remove the acid gas in the inner layer of silica.

[0004] To this end, the applicant developed a rotary silica deacidification system (CN 112209392A) in the early stage. However, the problem with this rotary deacidification system is that the acid gas removed by heating cannot be discharged in a direction, and the heating effect is poor due to the use of hot gas to heat the furnace body. On the other hand, since the rotary furnace cannot be completely sealed, there is a risk of acid leakage. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the acid gas removed by heating in the rotary deacidification system cannot be discharged in a directional manner, and the deacidification effect is poor due to the use of hot air to heat the furnace body.

[0006] In order to solve the above problems, the present application provides a rotary gas-phase silica deacidification device, comprising: a furnace body, a feed assembly and a discharge assembly, wherein the furnace body is a rotary furnace body; the feed assembly is arranged in front of the furnace body, and the furnace body and the feed assembly are connected by a bearing assembly, and the feed assembly is also provided with an acid discharge port for discharging the acidic gas; the discharge assembly is arranged behind the furnace body, and the furnace body and the discharge assembly are connected by a bearing assembly, and the discharge assembly is also provided with a heat source feed port for introducing high-temperature gas, and the heat source feed port, the furnace body, and the acid discharge port are connected.

[0007] In the above technical scheme of the present invention, the heat source feed port is arranged on the discharge component, the acid discharge port is arranged on the feed component, and the heat source feed port, the furnace body, and the acid discharge port are connected. During the deacidification process, the silica moves in a rotational manner in the furnace body, and the hot air entering the furnace body through the heat source feed port removes the acid in the silica, and then is discharged through the acid discharge port. Since the hot air enters the heat source feed port, the pressure of the heat source feed port is greater than the pressure of the acid discharge port, so the acid gas after deacidification can be directional discharged, and the high-temperature gas of the present invention is directly mixed with the silica, thereby improving the deacidification efficiency.

[0008] In order to achieve full contact between the high-temperature gas and the silica to be deacidified, as an improvement of the above-mentioned rotary gas-phase silica deacidification device, the furnace body is arranged at an angle, wherein the height of the furnace body feed is lower than the height of the furnace body discharge.

[0009] Since the density of high-temperature gas is relatively small, by making the height of the furnace feed point lower than the height of the furnace discharge point, the high-temperature gas enters the furnace body from the highest point and is discharged from the lowest end, so that the high-temperature gas can fill the entire furnace body, thereby achieving full contact between the high-temperature gas and the white carbon black to be deacidified.

[0010] In order to improve the sealing performance of the furnace body, as an improvement of the rotary gas phase silica deacidification device, a first high-pressure gas sealing component is further provided at the connection of the bearing component between the furnace body and the feeding component. A second high-pressure gas sealing component is further provided at the connection of the bearing component between the furnace body and the discharging component.

[0011] Since the furnace body and the feed assembly are connected by a bearing, there must be a gap at the connection. In order to prevent the acid gas after the deacidification of white carbon black in the furnace body from leaking from the gap of the bearing connection, this solution adopts a high-pressure gas sealing assembly to isolate the acid gas in the furnace body.

[0012] In order to prevent the high-temperature gas introduced into the furnace body from being discharged from the discharge port, a third high-pressure gas sealing component is provided at the discharge end of the discharge component.

[0013] In order to realize the directional discharge of the acid gas in the furnace body from the acid discharge port, as an option of the above-mentioned rotary gas phase silica deacidification device, an exhaust system is arranged at the acid discharge port to make the acid discharge port of the furnace body slightly negative pressure to ensure that the acid gas flows to the acid discharge port.

[0014] In order to realize the directional discharge of the acid gas in the furnace body from the acid discharge port, as another option of the above-mentioned rotary gas phase silica deacidification device, a blower is arranged at the heat source feed port.

[0015] Based on the above-mentioned deacidification device, the present invention also provides a method for deacidification of rotary gas-phase silica, comprising: rotating a rotary furnace body; continuously passing silica from a feed assembly into the rotary furnace body; simultaneously passing high-temperature gas into the furnace body from a heat source feed port, so that the high-temperature gas is in full contact with the silica in the furnace body; the heat source gas takes away the acidic gas in the silica and discharges it through the acid discharge port.

[0016] As an option for the high temperature gas, the high temperature gas is a high temperature gas containing water vapor generated by combustion of the gas to be combusted and air.

[0017] As the high temperature gas raw material configuration means, the volume ratio of the gas to be burned to the gas is 1:6.

[0018] As an option for the gas to be combusted in the above-mentioned high-temperature gas raw material configuration, the gas to be combusted is natural gas or hydrogen.

[0019] The beneficial effects of the present invention are:

[0020] 1. The heat source feed port of the present invention is arranged on the discharge assembly, the acid discharge port is arranged on the feed assembly, and the heat source feed port, the furnace body, and the acid discharge port are connected. During the deacidification process, the white carbon black moves in a rotary manner in the furnace body, and the hot air entering the furnace body through the heat source feed port removes the acid in the white carbon black and is then discharged through the acid discharge port. Since the hot air enters the heat source feed port, the pressure of the heat source feed port is greater than the pressure of the acid discharge port, so the acid gas after deacidification can be directional discharged, and the high-temperature gas of the present invention is directly mixed with the white carbon black, thereby improving the deacidification efficiency.

[0021] 2. If water is used for electric heating, the water vapor needs to be heated to 600°C by electric heating. The water contains a lot of impurity ions, which will carry trace impurities after turning into steam. During the deacidification process, trace impurities will be brought into the silica, affecting the purity of silica.

[0022] The present invention adopts the method of burning hydrogen or natural gas with air to form a high-temperature gas containing water for deacidification. Therefore, the high-temperature gas containing water produced by the combustion of hydrogen or natural gas with air will not carry other impurities and will not reduce the purity of the product after deacidification. This solves the problem that the prior art uses the method of heating water for deacidification, which causes the metal ions contained in the water to contaminate white carbon black.

[0023] 3. The hydrogen or natural gas used in the present invention is directly generated in the factory, which is convenient to source and low in cost. The purity of the hydrogen used is 99.9%, and the product has high purity and few impurities. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of a rotary fumed silica deacidification device of the present application;

[0025] Figure 2 yes Figure 1 Enlarged view of point a;

[0026] Description of reference numerals:

[0027] 1. Furnace body; 2. Feed assembly; 21. Feed port; 22. Acid discharge port; 3. Discharge assembly; 31. Discharge port; 32. Heat source feed port; 41. First high-pressure gas sealing assembly; 42. Second high-pressure gas sealing assembly, 43. Third high-pressure gas sealing assembly. DETAILED DESCRIPTION

[0028] The following will be combined with the attached Figures 1-2 The embodiments of the technical solution of the present application are described in detail. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the protection scope of the present application.

[0029] like Figure 1 An embodiment of a rotary gas-phase silica deacidification device provided in the present application is illustrated, and the rotary gas-phase silica deacidification device comprises: a furnace body 1, a feed assembly 2 and a discharge assembly 3, wherein the furnace body 1 is a rotary furnace; the feed assembly 2 is arranged in front of the furnace body 1, and the furnace body 1 and the feed assembly 2 are connected by a bearing assembly (not shown in the figure), and the feed assembly 2 is also provided with an acid discharge port 22 for discharging the acid gas; the discharge assembly 3 is arranged behind the furnace body 1, and the furnace body 1 and the discharge assembly 3 are connected by a bearing assembly (not shown in the figure), and the discharge assembly 3 is also provided with a heat source feed port 32 for introducing high-temperature gas, and the heat source feed port 32 is connected to the furnace body 1 and the acid discharge port 22.

[0030] It should be noted that the rotary furnace body 1, the feeding assembly 2 and the discharging assembly 3 used in the present application are improved from the prior art.

[0031] The furnace body 1 used in this application is designed to be rotary. Specifically, the rotary furnace body 1 is designed to be long cylindrical in shape, and the material is preferably high temperature resistant and corrosion resistant stainless steel. The length of the furnace body 1 is customized according to the actual production volume requirements, and the diameter is determined according to the amount of white carbon black to be processed. Spiral blades are provided inside the furnace body to guide the white carbon black to move evenly in the furnace body and increase its contact area with the hot air. The furnace body 1 is equipped with a transmission device to make the rotary kiln rotate normally at the speed required by the process, and the speed can be adjusted within a certain speed range as needed. The driving mode of the rotary kiln (not shown in the figure) can be motor-driven, hydraulic-driven or engine-driven, etc., which is not limited here. The feeding assembly 2 is installed at the front end of the furnace body 1 and is connected to the furnace body through a bearing assembly to ensure that the furnace body does not affect the feeding operation when rotating. The deacidification equipment using a rotary furnace body helps the gas phase white carbon black to flow evenly in the furnace body, reduces the situation where the inner layer of white carbon black is wrapped by the outer layer, and thus improves the deacidification effect.

[0032] The feed assembly 2 is used to pass the material into the furnace body 1. Generally speaking, the feed assembly includes a feed port 21, a feed channel, etc. The feed channel can be selected as a spiral feeding mechanism, etc., and the present application does not limit this. On this basis, those skilled in the art can also set a metering mechanism on the feed assembly 2 to achieve metering of the feed material. In an embodiment of the present application, an acid discharge port 22 is also specially provided on the feed assembly 2 to facilitate timely discharge of the acid gas containing HCl generated in the deacidification process. Through the acid discharge port, the acid gas generated in the heating acid discharge process can be directionally discharged.

[0033] The discharge assembly 3 is located at the rear of the furnace body 1, and is also connected to the furnace body through a bearing assembly, ensuring that the discharge operation is not disturbed when the furnace body rotates. The main function of the discharge assembly 3 is to smoothly discharge the deacidified silica, which mainly includes a discharge port 31, etc. In an embodiment of the present application, a heat source feed port 32 is also provided on the discharge assembly 3 for introducing high-temperature gas into the furnace body. The heat source feed port 32 is connected to the interior of the furnace body 1 and the acid discharge port 22, ensuring that the high-temperature gas can be evenly distributed throughout the furnace body, and the acid gas carried by it is brought out through contact with the silica. A heat source feed port 32 is provided on the discharge assembly 3 for introducing high-temperature gas. Compared with indirect heating by introducing high-temperature gas into the furnace body, directly adding high-temperature gas into the furnace body improves the heating effect and makes the gas phase silica heated more evenly.

[0034] The steps of performing deacidification treatment using the rotary gas-phase silica deacidification device provided in the above embodiment are as follows: start the equipment to ensure that all components are in normal working condition; continuously feed the silica to be treated into the interior of the furnace body 1 through the feed component 2; blow pre-heated high-temperature gas into the furnace body through the heat source feed port 32; the rotary furnace body rotates so that the silica moves forward in the furnace body as the furnace body rotates; as the silica is fully in contact with the high-temperature gas, the acidic substances contained in the silica are carried out by the high-temperature gas and discharged to the external treatment system under the guidance of the acid discharge port 22; when the silica completes the entire deacidification process and reaches the end of the furnace body 1, it is collected by the discharge component 3.

[0035] In the rotary gas-phase silica deacidification device provided by the above embodiment, the heat source feed port is arranged on the discharge component, the acid discharge port 22 is arranged on the feed component 2, and the heat source feed port 32, the furnace body 1, and the acid discharge port 22 are connected. During the deacidification process, the silica moves in a rotary manner in the furnace body, and the high-temperature gas entering the furnace body through the heat source feed port 32 removes the acid in the silica, and then is discharged through the acid discharge port 22. Since the heat source feed port 32 enters the high-temperature gas, the pressure of the heat source feed port 32 is greater than that of the acid discharge port 22, so that the acid gas after deacidification can be directional discharged, and the high-temperature gas of the present invention is directly mixed with the silica, thereby improving the deacidification efficiency.

[0036] like Figure 1 In one embodiment, the furnace body 1 is tilted, wherein the height of the furnace body 1 at the feeding point is lower than the height of the discharging point.

[0037] In order to ensure that the high-temperature gas can fully contact the white carbon black to be deacidified, the present invention further improves the design of the furnace body 1. Specifically, the furnace body 1 is not placed horizontally, but is tilted at a certain angle so that the feed end is lower than the discharge end. Since the high-temperature gas has a low density, when the high-temperature gas enters from the higher end of the furnace body, due to its natural upward trend, it will form a top-down flow path in the furnace body 1 and finally leave the furnace body from the lower end. In this way, it can be distributed throughout the furnace body, thereby significantly enhancing the mass transfer efficiency between the high-temperature gas and the white carbon black.

[0038] In this embodiment, the high-temperature gas is introduced through the heat source feed port 32 provided on the discharge assembly 3. After the high-temperature gas enters the furnace body 1, it gradually flows to the lower end of the furnace body, i.e., the feed end, due to the inclined arrangement of the furnace body 1. In this process, the high-temperature gas is fully mixed with the white carbon black that is constantly moving forward, which effectively promotes the evaporation of the acidic substance. Finally, the high-temperature gas containing the acidic substance is discharged through the acid discharge port 22.

[0039] like Figure 1-2In one embodiment, a first high-pressure gas sealing component 41 is further provided at the bearing assembly connection between the furnace body 1 and the feed assembly 2. A second high-pressure gas sealing component 42 is further provided at the bearing assembly connection between the furnace body 1 and the discharge assembly 3.

[0040] The first high-pressure gas sealing assembly 41 and the second high-pressure gas sealing assembly 42 are both used for the connection between the furnace body 1 and the feed assembly 2 and the discharge assembly 3. Their main purpose is to provide a reliable sealing effect under high-temperature and high-pressure working environments. Specifically, the first high-pressure gas sealing assembly 41 is located at the bearing assembly connection between the furnace body 1 and the feed assembly 2, and is responsible for preventing external gas or other impurities from entering the furnace and preventing the high-temperature acidic gas in the furnace from leaking. The second high-pressure gas sealing assembly 42 is installed at the bearing assembly connection between the furnace body 1 and the discharge assembly 3, and is responsible for preventing external gas or other impurities from entering the furnace and preventing the high-temperature acidic gas in the furnace from leaking. These two sealing assemblies use a gas injection system for continuously injecting an appropriate amount of high-pressure gas, such as inert gas, nitrogen, etc.

[0041] In order to prevent the high-temperature gas introduced into the furnace from being discharged from the discharge port, a third high-pressure gas sealing component 43 is provided at the discharge end of the discharge component 3. The first high-pressure gas sealing component 41, the second high-pressure gas sealing component 42, and the third high-pressure gas sealing component 43 have the same principle, and all use compressed gas to achieve the effect of an air curtain to block the gas flow on both sides of the air curtain.

[0042] In one embodiment, an exhaust system is provided at the acid discharge port 22 (illustrated in the figure) so that the gas pressure at the acid discharge port is lower than the gas pressure in the furnace body. Generally, the gas pressure is -1 kPa compared to the pressure in the furnace. In this embodiment, the acid discharge port 22 is used to discharge acidic gases. In order to ensure that the furnace body maintains a positive pressure state and effectively prevent the acidic gas from directly leaking into the atmosphere to pollute the environment, the present invention proposes to provide a dedicated exhaust system at the acid discharge port 22. The system generates a negative pressure so that the gas pressure at the acid discharge port is always lower than the pressure inside the furnace body, thereby ensuring that all gases discharged from the furnace body can be collected and introduced into subsequent processing units.

[0043] In one embodiment, a blower is provided at the heat source feed inlet 32 ​​(illustrated in the figure). The blower is responsible for generating an airflow with a certain air volume and air pressure to transport the preheated gas to the heat source feed inlet 32 ​​.

[0044] The present invention also provides a rotary gas phase silica deacidification method, the specific steps include but are not limited to:

[0045] Rotate the rotary furnace body 1; introduce high-temperature gas into the furnace body 1 from the heat source feed port 32; continuously introduce white carbon black from the feed assembly 2 into the rotary furnace body 1; make the high-temperature gas fully contact with the white carbon black in the furnace body 1; the heat source gas takes away the acidic gas in the white carbon black and discharges it through the acid discharge port 22.

[0046] Preferably, the high temperature gas is a high temperature gas containing water vapor generated by the combustion of the gas to be burned and air. In order to obtain a better deacidification effect, the present embodiment uses the high temperature gas containing water vapor generated by the combustion of the gas to be burned and air as the high temperature gas. This combustion process not only provides sufficient heat, but also the water vapor generated by the combustion also helps to desorb the acidic components in the white carbon black.

[0047] If the deacidification of white carbon is carried out by directly heating water to become water vapor, metal impurities are introduced into the white carbon during the dehydration process because the water contains a variety of impurity ions. However, the present application is more environmentally friendly by burning hydrogen or natural gas and air to produce water-containing high-temperature gas. The temperature of the water-containing high-temperature gas produced by burning hydrogen or natural gas and air is higher than 600°C, and no additional impurities are introduced, and the purity of the product after deacidification is higher. In a preferred embodiment, the purity of the hydrogen or natural gas used is not less than 99.9%.

[0048] Generally, the volume ratio of the gas to be burned to the gas is 1:3, and in the present application, preferably, in order to control the moisture content of the product, the combustion ratio is increased to hydrogen or natural gas: gas volume ratio of 1:6, and the high-temperature gas introduced into the furnace body is at a slightly positive pressure.

[0049] Application example: The flow rate of white carbon black with a pH of 3.0 into the furnace body 1 is 500 kg / h, and the flow rate of high-temperature gas containing water (gas after combustion with a hydrogen: gas volume ratio of 1:6) is 50 m 3 / h, the pH value of the white carbon black obtained after the final treatment is ≥4.3, and no change is detected in the content of metal impurities in the white carbon black before and after deacidification; in this application example, the diameter of the furnace body 1 is 1m, the length is 15m, the rotation speed is 2r / min, and the inclination angle of the furnace body is 5°.

[0050] Comparative Example: Deacidification was performed using the deacidification system CN 112209392A developed earlier by the applicant. The flow rate of white carbon with a pH value of 3.0 was 500 kg / h in the furnace body 1, and the furnace body was heated. The pH value of the white carbon obtained after the final treatment was ≥ 4.0. In this comparative example, the diameter of the furnace body 1 was 1 m, the length was 15 m, the rotation speed was 2 r / min, the furnace body was horizontal, and the natural gas flow rate of the heating burner was 50 m 3 / h, primary air flow rate is 150m 3 / h, secondary air flow rate is 150m 3 / h.

[0051] Finally, it should be noted that: unless otherwise defined, all technical and scientific terms used in this document have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in this document are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0052] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "set", "provided with", "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection, or a mechanical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0053] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A rotary fumed silica deacidification device, characterized in that: include: A rotary furnace body (1); A feed assembly (2) is arranged in front of the furnace body (1), the furnace body (1) and the feed assembly (2) are connected via a bearing assembly, and the feed assembly (2) is also provided with an acid discharge port (22) for discharging the acid gas; A discharge assembly (3) is arranged behind the furnace body (1); the furnace body (1) and the discharge assembly (3) are connected via a bearing assembly; the discharge assembly (3) is also provided with a heat source feed port (32) for introducing high-temperature gas; the heat source feed port (32), the furnace body (1) and the acid discharge port (22) are in communication.

2. The rotary fumed silica deacidification device according to claim 1, characterized in that: The furnace body (1) is arranged tilted, wherein the height of the furnace body (1) at the inlet is lower than the height of the furnace body at the outlet.

3. The rotary fumed silica deacidification device according to claim 1, characterized in that: A first high-pressure gas sealing component (41) is also provided at the bearing component connection between the furnace body (1) and the feed component (2), and a second high-pressure gas sealing component (42) is also provided at the bearing component connection between the furnace body (1) and the discharge component (3).

4. The rotary fumed silica deacidification device according to claim 1, characterized in that: A third high-pressure gas sealing component (43) is provided at the discharge end of the discharge component (3).

5. The rotary fumed silica deacidification device according to claim 1, characterized in that: An exhaust system is provided at the acid discharge port (22) so that the gas pressure at the acid discharge port is lower than the gas pressure in the furnace body.

6. The rotary fumed silica deacidification device according to claim 1, characterized in that: A blower is arranged at the heat source feed inlet (32).

7. A method for deacidification of rotary fumed silica, characterized in that: include: Rotating a rotary furnace body (1); Continuously introducing white carbon black from a feed assembly (2) into a rotary furnace body (1); At the same time, high-temperature gas is introduced into the furnace body (1) from the heat source feed port (32), so that the high-temperature gas is in full contact with the white carbon black in the furnace body (1); The heat source gas takes away the acidic gas in the white carbon black and discharges it through the acid discharge port (22).

8. The method for deacidification of rotary fumed silica according to claim 7, characterized in that: The high temperature gas is a high temperature gas containing water vapor generated after the combustion of the gas to be burned and air.

9. The method for deacidification of rotary fumed silica according to claim 8, characterized in that: The volume ratio of the gas to be burned to the air is 1:

6.

10. The method for deacidification of rotary fumed silica according to claim 8, characterized in that: The gas to be burned is natural gas or hydrogen.

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