CN-121775792-B - Stirring method for coated asphalt reactor

CN121775792BCN 121775792 BCN121775792 BCN 121775792BCN-121775792-B

Abstract

The invention discloses a stirring method for a coated asphalt reactor, which comprises the following steps of introducing oxidizing gas into a reaction kettle, controlling a stirring assembly to operate in a first operation state, providing a shearing action by utilizing a lower layer shearing type stirring paddle to disperse the gas, and maintaining a gas-liquid mixing flow field by utilizing an upper layer circulating type stirring paddle, and stopping introducing the oxidizing gas into the reaction kettle, and controlling the stirring assembly to operate in a second operation state, wherein the stirring strength of the second operation state is lower than that of the first operation state, so that the shearing action is reduced, the whole kettle circulation is maintained, and bubbles are prevented from being difficult to escape under a heterogeneous fluid system due to too fine shearing. Can adapt to the great change of the material viscosity, and improves the uniformity and the production stability of the product.

Inventors

CHEN DEGAO
YE ZHICAI
WU LIANG
CHEN JIANQI
Zhang Yulao
XU BENCHI
WANG QIANGMIN
CHEN ZENGHUI
MIAO BINBIN
WU WENJIANG

Assignees

浙江长城搅拌设备股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260306

Claims (10)

1. The stirring method for the coated asphalt reactor is characterized in that a stirring system is used for processing reaction materials, the stirring system comprises a reaction kettle and stirring components arranged in the reaction kettle, and the stirring components are arranged in layers in the vertical direction and comprise a shearing type stirring paddle positioned at the lower layer and a circulating type stirring paddle positioned at the upper layer; the method comprises the following steps: An oxidation reaction stage, namely introducing oxidizing gas into the reaction kettle, controlling the stirring assembly to operate in a first operation state, providing shearing action by using a lower-layer shearing type stirring paddle to disperse the gas, and maintaining a gas-liquid mixing flow field by using an upper-layer circulating type stirring paddle; And in the stripping stage, the oxidizing gas is stopped being introduced, a stripping medium is introduced into the reaction kettle, and the stirring assembly is controlled to operate in a second operation state, wherein the stirring intensity in the second operation state is lower than that in the first operation state, so that the shearing action is reduced, the whole kettle circulation is maintained, and the bubble is prevented from being difficult to escape under a heterogeneous fluid system due to too fine shearing.
2. The stirring method for a coated asphalt reactor according to claim 1, wherein the lower shearing type stirring paddle is a disk turbine type stirring paddle, and the upper circulating type stirring paddle is an axial flow stirring paddle.
3. The stirring method for coating an asphalt reactor according to claim 2, wherein the blades of the turbine-type stirring blade have a parabolic blade profile structure, and the blade tips of the turbine-type stirring blade are provided with a tuning fork structure or a blade tip differential structure to enhance the breaking capacity against a gas-liquid interface.
4. The stirring process for a coated bitumen reactor of claim 1, wherein during the oxidation reaction stage the first operating state satisfies at least one of the following parameter conditions: The linear speed of the leaf end of the stirring assembly is controlled to be 6.0-7.0 m/s; the power consumption per unit volume of the stirring system is controlled to be 1.0-2.5 kW/m 3 ; the stirring system produces an average volumetric shear rate in the material of not less than 50s- 1 .
5. The stirring process for a coated bitumen reactor of claim 1 or 4, wherein during the stripping phase the second operating conditions meet at least one of the following parameter conditions: the linear speed of the leaf end of the stirring assembly is controlled to be 1.5-3.5 m/s; The power consumption per unit volume of the stirring system is controlled to be 0.3-1.0 kW/m 3 ; The stirring system produces an average volumetric shear rate in the material of no more than 30s- 1 .
6. The stirring method for a coated asphalt reactor according to claim 1, further comprising a discharging stage after the stripping stage, wherein the stirring assembly is maintained to operate in the second operation state in the discharging stage and is matched with steam purging in the discharging process, the stirring cycle times of the stripping stage and the discharging stage are controlled to be 8-12 times/min, and the cycle times of the stirring system are controlled to be more than or equal to 15 times/min in the oxidation reaction stage.
7. The stirring method for a coated asphalt reactor according to claim 1, wherein, The ratio of the shearing type stirring paddle to the inner diameter of the reaction kettle is 0.4-0.55, and the ratio of the diameter of the circulating type stirring paddle to the inner diameter of the reaction kettle is 0.55-0.70.
8. The stirring method for a coated asphalt reactor according to claim 1, wherein the stirring system further comprises a ring-type gas distributor arranged at the bottom of the reaction kettle, wherein the ring-type gas distributor is provided with gas outlet holes which are opened upwards, the oxidizing gas and the stripping medium enter the reaction kettle through the ring-type gas distributor in the oxidation reaction stage and the stripping stage, gas coalescence is prevented by utilizing the upward gas outlet direction, the gas outlet speed of the gas outlet holes is 12m/s +/-15%, and the ring pipe opening ratio of the open pore flow area/the ring pipe cross section flow area is 80-90%.
9. The stirring method for a coated asphalt reactor according to claim 1, wherein the stirring system further comprises a tubular baffle arranged inside the reaction kettle, and the method comprises the steps of utilizing the tubular baffle to exchange heat and rectify, and adopting sectional heat exchange to ensure heat exchange requirements under different liquid levels and avoid dry burning and coking.
10. The stirring method for a coated asphalt reactor according to claim 1, wherein the reaction vessel adopts an elliptical head structure with a large upper part and a small lower part, and the method comprises gas-liquid separation by utilizing an upper space provided by the elliptical head structure.

Description

Stirring method for coated asphalt reactor Technical Field The invention relates to a stirring technology, in particular to a stirring method for a coated asphalt reactor. Background The coated asphalt is a key material for coating the surface of the anode material of the lithium ion battery, and the production process of the coated asphalt generally comprises two core stages of oxidative polymerization and steam stripping of ethylene tar. The two stages have obvious difference or even contradiction on the requirements of a stirring flow field, namely the oxidation reaction stage mainly relates to gas-liquid two-phase reaction, the introduced oxidizing gas is crushed into tiny bubbles by extremely strong shearing action to increase the contact area of gas and liquid and promote the reaction, and the stripping stage needs to remove dissolved small molecular light components and bubbles from the liquid phase under a high-viscosity system, if the high shearing action is continuously maintained, the bubbles are easily cut into excessively fine bubbles, so that the bubbles cannot be gathered and float in the viscous feed liquid, serious bubble entrainment or flooding phenomenon is caused, and the product quality and the production stability are influenced. Existing stirring systems or methods typically employ a single combination of paddles or a constant mode of operation, which makes it difficult to address both of the two distinct process requirements. For example, if the high shear design is focused on the oxidation stage, the devolatilization is easily performed due to the too strong shear in the stripping stage, and if the cyclic mixing design is focused on the oxidation stage, the gas-liquid dispersion effect is poor, and the reaction efficiency is low. In addition, as the reaction proceeds, the viscosity of the material increases rapidly from tens of millipascal-seconds to thousands of millipascal-seconds, and conventional stirring methods tend to form flow dead zones on the wall or bottom of the reaction kettle, resulting in localized overheating and coking, and difficult to accommodate flow field challenges caused by large changes in the viscosity of the whole kettle. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a stirring method for a coated asphalt reactor, which can adapt to the great change of the viscosity of materials and improve the uniformity and the production stability of products. In order to achieve the aim, the invention provides a stirring method for coating an asphalt reactor, which adopts a stirring system to treat reaction materials, wherein the stirring system comprises a reaction kettle and stirring components arranged in the reaction kettle, and the stirring components are arranged in layers in the vertical direction and comprise a shearing type stirring paddle positioned at the lower layer and a circulating type stirring paddle positioned at the upper layer; the method comprises the following steps: An oxidation reaction stage, namely introducing oxidizing gas into the reaction kettle, controlling the stirring assembly to operate in a first operation state, providing shearing action by using a lower-layer shearing type stirring paddle to disperse the gas, and maintaining a gas-liquid mixing flow field by using an upper-layer circulating type stirring paddle; And in the stripping stage, the oxidizing gas is stopped being introduced, a stripping medium is introduced into the reaction kettle, and the stirring assembly is controlled to operate in a second operation state, wherein the stirring intensity in the second operation state is lower than that in the first operation state, so that the shearing action is reduced, the whole kettle circulation is maintained, and the bubble is prevented from being difficult to escape under a heterogeneous fluid system due to too fine shearing. As a further improvement of the invention, the lower layer shearing type stirring paddle is a disk turbine type stirring paddle, and the upper layer circulating type stirring paddle is an axial flow stirring paddle. As a further improvement of the invention, the blades of the disc turbine type stirring paddle adopt a parabolic blade-shaped structure, and the tail ends of the blades of the disc turbine type stirring paddle are provided with a tuning fork structure or a blade end differential structure so as to enhance the breaking capacity of a gas-liquid interface. As a further development of the invention, in the oxidation reaction stage, the first operating state satisfies at least one of the following parameter conditions: The linear speed of the leaf end of the stirring assembly is controlled to be 6.0-7.0 m/s; the power consumption per unit volume of the stirring system is controlled to be 1.0-2.5 kW/m 3; the stirring system produces an average volumetric shear rate in the material of not less than 50s- 1. As a further development of the invention,