阅读说明：本技术 一种强化低温精馏分离的旋转磁场装置及精馏塔 (Rotating magnetic field device for strengthening low-temperature rectification separation and rectification tower ) 是由 植晓琴 顾陈杰 张晗阳 邱利民 于 2020-05-21 设计创作，主要内容包括：本发明涉及一种强化低温精馏分离的旋转磁场装置及精馏塔,属于低温精馏空气分离技术领域。包括：均匀设置在填料层周围的三组铁芯,所有铁芯上缠绕有方向相同的金属线圈；金属线圈内通入正弦型交流电,同一个铁芯组的两个金属线圈所通交流电的电流方向相反,且相邻铁芯组所通的交流电的相位相差120°。通过在填料层周围配置三对交流电绕组,在填料内实现单向旋转磁场,对填料内部工质中的氧组分施加旋转的磁力矩,强化填料表面的气液逆流降膜传质过程。(The invention relates to a rotating magnetic field device for strengthening low-temperature rectification separation and a rectification tower, belonging to the technical field of low-temperature rectification air separation. The method comprises the following steps: three groups of iron cores are uniformly arranged around the packing layer, and all the iron cores are wound with metal coils in the same direction; the metal coils are internally provided with sine alternating current, the current directions of the alternating current conducted by the two metal coils of the same iron core group are opposite, and the phase difference of the alternating current conducted by the adjacent iron core groups is 120 degrees. Three pairs of alternating current windings are arranged around the filler layer, so that a unidirectional rotating magnetic field is realized in the filler, rotating magnetic torque is applied to oxygen components in working media in the filler, and the gas-liquid countercurrent falling film mass transfer process on the surface of the filler is strengthened.)

1. A rotating magnetic field device for strengthening low-temperature rectification separation is characterized by comprising three groups of iron cores which are uniformly arranged around a packing layer, wherein metal coils in the same direction are wound on all the iron cores;

sine alternating current is introduced into the metal coils, the current directions of the alternating current introduced into the two metal coils of the same iron core group are opposite, and the phase difference of the alternating current introduced into the adjacent iron core groups is 120 degrees.

2. The rotating magnetic field device for enhancing cryogenic rectification separation as recited in claim 1 wherein the iron core is mounted within a column wall of the rectification column and an end of the iron core adjacent to the packing layer is frustum-shaped.

3. The rotating magnetic field device for enhancing cryogenic rectification separation as claimed in claim 1, wherein a wall flow preventing ring is arranged around the packing layer.

4. The rotating magnetic field device for enhancing cryogenic rectification separation as claimed in claim 3, wherein the wall flow preventing rings are arranged along the top edge and the bottom edge of the packing layer.

5. The rotating magnetic field device for enhancing cryogenic rectification separation as claimed in claim 1, wherein the packing layer is cylindrical, adjacent iron cores are 60 degrees apart from the center of the packing layer, and the iron cores which are diametrically opposite along the packing layer are in the same group.

6. A rectifying tower is characterized in that a packing layer is arranged in the rectifying tower, and a rotating magnetic field device for strengthening low-temperature rectifying separation is arranged in any one of claims 1 to 5.

7. The rectifying tower according to claim 6, wherein a groove for mounting the iron core is provided on a tower wall of the rectifying tower.

Technical Field

The invention relates to the technical field of low-temperature rectification air separation, in particular to a rotating magnetic field device for strengthening low-temperature rectification separation and a rectification tower.

Background

China is the only country in the world currently having all the industrial categories in the united domestic industry classification, wherein industrial gas is an important basic material for supporting a plurality of industrial fields such as metallurgy, chemical industry, electronics, biology, medicine, food, aerospace and the like, and the production of industrial gas is one of the prop industries of the Chinese entity manufacturing industry. In 2017, the industrial gas market scale of China reaches 1200 hundred million yuan, and the annual composite growth rate reaches 10.16%. However, the unit energy consumption required by industrial gas production in China is still higher than the level of developed countries, and high energy consumption and high cost become problems to be solved urgently in the development of industrial gas industry.

At present, the low-temperature rectification method is most widely applied to large-scale preparation of high-purity oxygen, nitrogen and argon products, and has the advantages of mature technology, high product purity, high yield and the like. The principle of preparing industrial gas by low-temperature rectification is that interphase heat and mass transfer is carried out by utilizing the difference of boiling points of working media, and continuous and repeated partial evaporation and partial condensation are realized by the reflux in the tower, so that the aim of separating each component of air is fulfilled. Since the introduction of the Mellapak structured packing from Sulzer company into air separation plants in the 80 th 20 th century, the structured packing tower gradually replaced the traditional plate column in the cryogenic rectification process due to its excellent performance, promoting the technical change in the cryogenic air separation field. The regular packing defines a gas-liquid flow path through regular geometric arrangement and stacking, and the plate corrugated structure ensures that the regular packing has very high specific surface area and porosity, so that the regular packing has lower pressure drop, higher efficiency and capacity, the volume of the rectifying tower and the energy consumption of an air separation unit can be obviously reduced, and the full-rectification hydrogen-free argon preparation of the auxiliary tower can be realized.

The rectifying tower is the core of low-temperature air separation, and the energy consumption accounts for 30-40% of the total energy consumption of the air separation system. Even though the conventional structured packing is mature and applied to low-temperature air separation, the flow and mass transfer process in the rectifying tower still occupies most of the whole air separation flow path, and the effective energy loss of pressure drop and mass transfer respectively accounts for 15 percent and 55 percent of the total loss. Therefore, the cryogenic rectification packed tower still has a large performance improvement space, especially in the aspect of strengthening gas-liquid interphase mass transfer.

Currently, design optimization to improve the separation performance of rectification is mainly focused on the packing itself and the associated column internals. Chinese patent publication No. CN108479685A discloses a regular packing fixed wall flow ring, which is additionally provided with tongues to make packing more tightly attached to the column wall, thereby effectively inhibiting the wall flow. Chinese patent publication No. CN110449113A discloses a high-efficiency structured packing, in which the inlet and outlet of the packing are changed into vertical flow channels to reduce the interfacial resistance of the packing units, and increase the aperture ratio and wettability. However, as the installation and design technology of the packed tower matures, the improvement of the mass transfer efficiency of rectification by the optimization component is very limited. Therefore, there is a need for improvement in cryogenic rectification mechanisms to optimize separation performance.

Disclosure of Invention

The invention aims to provide a rotating magnetic field device for strengthening low-temperature rectification separation and a rectification tower, which can accelerate the update of the surface temperature and concentration of a liquid film and strengthen the heat and mass transfer process of a gas-liquid interface in a filler.

In order to achieve the above object, in a first aspect, the rotating magnetic field device for enhancing cryogenic rectification separation provided by the present invention comprises three groups of iron cores uniformly arranged around a packing layer, wherein all the iron cores are wound with metal coils in the same direction;

sine alternating current is introduced into the metal coils, the current directions of the alternating current introduced into the two metal coils of the same iron core group are opposite, and the phase difference of the alternating current introduced into the adjacent iron core groups is 120 degrees.

The air separation targets are mainly oxygen and nitrogen. Oxygen is the only component in air that has paramagnetism, while liquid oxygen is the pure liquid that has been found to have the highest paramagnetism. Under the standard state, the magnetic susceptibility of oxygen is 300 times that of nitrogen with diamagnetism. The magnetic reinforcing rectification filler utilizes the magnetism of oxygen to reinforce the heat and mass transfer process in the rectification filler, and oxygen can receive the effect of magnetic moment in a changing magnetic field, and the effect can make the magnetic moment of oxygen rotate towards the direction of an external magnetic field, so that each oxygen molecule can rotate along with the external magnetic field to generate vortex disturbance, the concentration updating of a gas-liquid interface is reinforced, and the mass transfer efficiency is further improved. In the technical scheme, three pairs of alternating current windings are arranged around the filler layer, a unidirectional rotating magnetic field is realized in the filler, rotating magnetic torque is applied to oxygen components in working media in the filler, and the gas-liquid countercurrent falling film mass transfer process on the surface of the filler is strengthened.

Optionally, in one embodiment, the iron core is installed in a tower wall of the rectifying tower, and one end of the iron core close to the packing layer is in a frustum shape. The wound metal coil can be prevented from falling off.

Optionally, in one embodiment, a wall flow prevention ring is arranged around the packing layer. The wall flow liquid can be prevented from flowing into the installation area of the iron core, so that the liquid is retained, and the normal operation of the rotating magnetic field device is influenced.

Optionally, in one embodiment, the anti-wall flow rings are disposed along top and bottom edges of the packing layer.

Optionally, in one embodiment, the packing layer is cylindrical, adjacent cores are separated by 60 ° with respect to the center of the packing layer, and the cores diametrically opposite along the packing layer are in the same group.

In a second aspect, the present invention provides a rectification column having a packing layer therein, and a rotating magnetic field device for enhancing cryogenic rectification separation as described above. And a groove for mounting the iron core is arranged on the tower wall of the rectifying tower. The iron core is arranged in the tower wall of the rectifying tower, so that the size is small, and the original function of the rectifying tower is not influenced.

Compared with the prior art, the invention has the advantages that:

the invention adopts three groups of alternating current coils to construct a rotating magnetic field in the filler, applies rotating magnetic torque to oxygen components in a liquid mixture in the filler, and can strengthen the surface concentration field and temperature field updating of a liquid film in the filler and strengthen the gas-liquid interface heat and mass transfer.

Drawings

FIG. 1 is a schematic structural diagram of a rotating magnetic field device disposed around structured packing in an embodiment of the present invention;

FIG. 2 is a schematic diagram of a rotating magnetic field apparatus using three-phase alternating current to generate a rotating magnetic field according to an embodiment of the present invention;

FIG. 3 is a diagram illustrating the alternating current phase of each iron core coil in accordance with an embodiment of the present invention;

FIG. 4 is a side cross-sectional view of an embodiment of the present invention with the iron core embedded in the rectifying tower wall;

fig. 5 is a top sectional view of the iron core embedded in the rectifying tower wall in the embodiment of the present invention.

The figures are numbered: 001-tower wall, 100-structured packing layer, 200-iron core, 201-metal coil, 300-wall flow prevention ring, 400-magnetic induction line and 500-magnetic field rotation direction.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described with reference to the following embodiments and accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of the word "comprise" or "comprises", and the like, in the context of this application, is intended to mean that the elements or items listed before that word, in addition to those listed after that word, do not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.