CN103272398A - Liquid distribution and redistribution device for multistage rotating rectification bed - Google Patents

Abstract

The invention relates to a multistage countercurrent rotary rectification bed, in particular to a liquid distributor and redistributor for a multistage rotary rectification bed. The present invention is to solve the problem of liquid distribution in the counter-current rotary packed bed, and proposes a multi-stage rotating rotary bed composed of a static liquid distribution tube and conical liquid distributor and a dynamic U-shaped and disc-shaped liquid distributor. Liquid distribution and redistributors for rectification beds. It includes three parts: liquid inlet pipe, conical liquid receiver and distributor and U-shaped flat disk rotating liquid distributor. It can be applied to various single-stage or multi-stage countercurrent rotating packed beds, which can strengthen the gas-liquid transfer process and improve transfer efficiency.

Description

Liquid distributor and redistributor for multi-stage rotary rectification bed

technical field

The invention relates to a multistage countercurrent rotary rectification bed, in particular to a liquid distributor and redistributor for a multistage rotary rectification bed.

Background technique

The rotary rectification bed is a new type of equipment that uses the centrifugal force field generated by the rotation of the packing to enhance the mass transfer and heat transfer process. Widely used in petroleum, chemical, pharmaceutical, explosives and other industries solvent recovery and product purification and other occasions. It has been proved by experiments and practice that the rotating packed bed can increase the mass and heat transfer coefficient by 1-2 orders of magnitude, and reduce the volume of equipment by 70 times. It is the transistor of the chemical industry in the 21st century. At present, most of the research and development are single-stage rotating packed beds with different structures, which are limited in processing capacity and separation effect. Multi-stage rotating packed beds are the development direction of industrialization.

According to the way of vapor-liquid contact, the rotating packed bed is divided into countercurrent, cross-flow and baffled flow. The structural principle of the counter-flow packed bed is that the ring-shaped packed bed composed of wire mesh packing (or other packing) rotates at high speed under the drive of the motor, and the liquid is evenly sprayed from the static inner cavity in the middle of the packed bed to the The inner wall of the rotating packing, under the action of high-speed rotation, the liquid moves radially outward in the packing, and at the same time, the gas enters the inner cavity of the packing from the periphery of the packing under pressure, and the liquid and gas are in reverse contact. Under the action of strong centrifugal force, the liquid has the characteristics of high dispersion and strong mixing, which greatly strengthens the mass transfer and reaction process.

The effect of the single-layer rotating packed bed is average, and it is generally used in the multi-stage rotating packed bed. The flow of the liquid is divided into two parts, one part is the liquid outside the equipment, which enters the rotating packed bed through the pipeline, and the other part is the liquid thrown out by the upper packing in the rotating packed bed, and the two parts of the fluid are sprayed on the inner edge of the packing through the liquid distributor , and then thrown out from the inside to the outside under the action of centrifugal force, leaving the rotating packing bed after multi-stage rotating packing. The gas enters from the bottom of the rotating packed bed. Due to its hydrodynamic properties, it first fills the entire outer cavity of the lower part of the rotating packed bed, and then passes through the packing from the outside to the inside under the action of pressure, and the gas and liquid flowing out from the inside of the packing pass through the top from the outside to the inside. After the multi-layer packing leaves the rotating packed bed.

In the rotating packed bed, the gas-liquid flow path is the gas-liquid mass transfer and heat transfer process. Therefore, the liquid distributor, the uniform distribution of fillers and the utilization of equipment space are the main factors to improve the overall performance of the equipment. The structural characteristics of the rotary packing are that the inner wall is a cylindrical structure with a certain height and circumference. Because all liquids must first reach the inner wall of the rotating packing to react, the liquid distributor is one of the important factors to determine the effect of mass transfer reaction. The most common problem is that after the liquid enters the inner side of the packing, due to the action of gravity, it is mainly distributed in the lower layer of the packing, and the liquid distribution is not uniform enough, and multi-stage packing is required in the scale-up of the countercurrent rotating packed bed project, so how to make the liquid uniform Distribution to the inner wall of the filler is a technical problem that we need to solve.

Contents of the invention  

The present invention is to solve the problem of liquid distribution in the counter-current rotating packed bed, and proposes a multi-stage rotating rotary bed consisting of a pipe-type and conical liquid distributor with static liquid distribution and a dynamic U-shaped and disc-type liquid distributor. Liquid distribution and redistributors for rectification beds. It can be applied to various single-stage or multi-stage counter-current rotating packed beds, which can strengthen the gas-liquid transfer process and improve transfer efficiency.

The present invention is realized by the following technical scheme, a liquid distributor and redistributor for a multi-stage rotary rectification bed, including three parts: a liquid inlet pipe, a conical liquid receiving and distributor and a U-shaped flat disk rotating liquid distributor.

The front end of the liquid inlet pipe is provided with N liquid distribution grooves. There are N spiral grooves on the conical liquid receiver and distributor. The structure of the U-shaped flat disk rotating liquid distributor includes a cylinder, a hollow annular flat disk and an annular U-shaped groove. The annular flat disk is installed on the lower edge of the outer side of the cylinder, and the annular U-shaped groove is installed on the upper edge of the outer side of the cylinder. A small hole is arranged at the bottom of the U-shaped groove. There are N U-shaped flat-disc rotating liquid distributors. The diameter and axial height of each U-shaped flat-disc rotating liquid distributor are different. The axial height of the larger diameter is smaller. According to the diameter of the cylinder, it is concentric. , arranged from bottom to top.

The positions of the N liquid distribution grooves correspond to the positions of the N U-shaped flat disk rotating liquid distributors. The N U-shaped flat disk rotary liquid distributors are connected to the rotary packing. The outer side of the conical liquid receiver and distributor is connected to the cylinder of the rotating packed bed, and the N spiral groove ends on the inner side of the conical liquid receiver and distributor correspond to the positions of N U-shaped flat disk rotating liquid distributors. The lower side of the conical liquid receiver and distributor is provided with a labyrinth seal. N is not less than 2 in the above scheme.

Compared with the existing devices, the present invention is characterized in that it uses a comprehensive liquid distributor composed of three structures including a liquid inlet pipe, a conical liquid receiving and distributor and a U-shaped flat disk rotating liquid distributor. Has the following characteristics:

(1) According to the different liquid handling capacity, there are N small grooves on the liquid inlet pipe for preliminary distribution of raw materials, and the liquid flowing out from each small groove flows to each of the U-shaped flat disk rotating liquid distributors in turn. U-shaped groove.

(2) The U-shaped flat disk rotating liquid distributor is equipped with N concentric U-shaped liquid receiving and distribution grooves and corresponding flat disk distributors in the radial direction. U-shaped liquid receiving and distribution groove, used to collect and evenly distribute the liquid from the liquid inlet pipe and the conical liquid receiving distributor in the circumferential direction. The U-shaped groove is circular, and its bottom is symmetrically provided with a plurality of small holes with the same diameter, which are used for evenly distributing the liquid on the U-shaped liquid receiving groove in the circumferential direction. An outwardly expanding circular disk is closely connected to the bottom of each U-shaped groove through a cylinder, and each disk is evenly distributed in the axial direction of the filler. In this way, the liquid can be evenly distributed axially and circumferentially on the inner wall of the packing after passing through the U-shaped flat disk rotating distributor.

(3) Considering the structure of the multi-stage packed bed, the conical liquid receiving and distributor is connected with the cylinder of the rotating packed bed to collect and distribute the liquid thrown out from the upper layer of packing. The conical liquid receiver and distributor is divided into N parts according to the liquid handling capacity, so that the liquid flows spirally on the conical liquid receiver and distributor, so as to prolong the upper flow distance of the liquid on the conical liquid receiver and distributor, so that Adequate mass and heat transfer with countercurrent gas. The outlet of the conical liquid receiver and distributor is provided with N U-shaped liquid separation tanks, which are used to distribute the liquid on the conical liquid receiver plate to each U-shaped groove on the U-shaped flat plate rotating liquid distributor. There is a labyrinth seal at the bottom of the cone-shaped liquid receiver and the inner edge of the distributor, which can effectively seal the gas.

(4) There are gas passages between each U-shaped groove and each flat plate on the U-shaped flat-disc rotating liquid distributor, so that the gas-liquid can be in countercurrent contact on the U-shaped flat-disc rotating liquid distributor, and the transmission can be carried out. mass heat transfer.

The beneficial effects of the present invention are: (1) The liquid enters the rotary packed bed through the liquid inlet pipe and is initially distributed; (2) The liquid thrown out from the upper packing in the rotary packed bed is first collected by the conical liquid receiving and distributor and preliminary distribution. On the conical liquid receiver and distributor, the liquid flows in a spiral to prolong the flow distance of the liquid on the unit area of the conical liquid receiver and distributor, so that it can conduct sufficient mass transfer and heat transfer with the countercurrent gas. The U-shaped liquid separation tank installed at the inner edge of the conical liquid receiver and distributor will evenly distribute the liquid on the conical liquid receiver and distributor; (3) The above two liquids are combined and enter the U-shaped flat plate rotating liquid The distributor is redistributed through multiple U-shaped grooves, liquid distribution holes at the bottom of the grooves and a flat plate, and the liquid is evenly sprayed on the inner surface of the packing in the axial and circumferential directions. Then it passes through the packing of the following stages step by step and leaves the rotating packed bed. (4) The gas enters from the bottom of the rotating packed bed, passes through the bottom layer of packing from outside to inside under the action of pressure, and then passes through the U-shaped flat disk rotating liquid distributor and the conical liquid receiving and distributor in turn to reach the upper layer of packing. The packing, the U-shaped flat disk rotating liquid distributor and the conical liquid receiver and distributor are all in countercurrent contact with gas and liquid, and can perform sufficient mass and heat transfer.

According to the multi-stage countercurrent rotary rectification packed bed, the present invention proposes a liquid distributor and redistributor, which uses a liquid distributor formed by a combination of various structures, which not only enables the liquid to form a good initial radial direction in the liquid distributor. , axial and circumferential distribution, and through the tortuous flow of gas and liquid in the liquid distributor and redistributor, the residence time of the liquid in the rotating packed bed can be prolonged, the uniform distribution and redistribution of the liquid in the equipment can be realized, and the efficiency of the equipment can be improved. Mass transfer effect and space utilization rate, and realize the gas seal between the upper and lower layers of packing, it is a liquid multifunctional distributor with simple structure and convenient installation. The structure is simple and the function is strong, and it can be applied to various single-stage or multi-stage countercurrent rotating packed beds, which can strengthen the gas-liquid transfer process and improve the transfer efficiency.

Description of drawings

Fig. 1 is the top view of the present invention

Fig. 2 is A-A sectional view of the present invention

Fig. 3 is the application structure of the liquid distributor of the present invention in a multi-stage rotating bed

Fig. 4 is the application of the rotary bed of the liquid distributor of the present invention in rectification operation

Reference signs: 1-liquid inlet pipe, 2-liquid distribution tank, 3-U-shaped liquid separation tank, 4-conical liquid receiver and distributor, 5-spiral groove, 6-maze, 7-U-shaped flat disk rotation Liquid distributor, 8-liquid distribution hole, 9-demister, 10-gas outlet, 11-shaft, 12-filler, 13-liquid outlet, gas inlet, 14-reflux liquid inlet.

Detailed ways

As shown in Figures 1 and 2, a liquid distributor and redistributor for a multi-stage rotary rectification bed includes three parts: a liquid inlet pipe 1, a conical liquid receiving and distributor 4 and a U-shaped flat disk rotating liquid distributor 7 ; Here N is not less than 2, any value between 2-10 can be selected according to the size of the filler, and 4 is taken here.

The front end of the liquid inlet pipe 1 is provided with 4 liquid distribution grooves 2, the conical liquid receiving and distributor 4 is provided with 4 spiral grooves 5, and the structure of the U-shaped flat disk rotating liquid distributor 7 includes a flat disk, a ring of a flat disk A U-shaped liquid separation tank 3 is provided on the inner wall of the U-shaped liquid separation tank, and a liquid distribution hole 8 is provided at the bottom of the U-shaped liquid separation tank. There are 4 U-shaped flat disk rotating liquid distributors 7, and they are in the shape of concentric circles. According to the diameter of the flat disk from small to Large, arranged from bottom to top. the

The positions of the four liquid distribution tanks 2 correspond to the positions of the four U-shaped flat disk rotating liquid distributors 7, and the four U-shaped flat disk rotating liquid distributors 7 are respectively connected to the filler 12, and the cone The outer side of the shaped liquid receiver and distributor 4 is connected to the cylinder of the rotating packed bed, and the inner ends of the four spiral grooves on the inner side of the conical liquid receiver and distributor 4 correspond to the positions of the four U-shaped flat disk rotating liquid distributors 7. A labyrinth seal 6 is provided on the lower side of the conical liquid receiver and distributor 4 .

In this way, four elongated liquid distribution tanks 2 are vertically opened downward on the horizontal liquid inlet pipe 1, and the liquid can be preliminarily distributed, so that the liquid can be evenly distributed to the four U-shaped flat disk rotating liquid distributors 7.

The conical liquid receiving and distributor 4 is divided into 4 spiral channels, so that the liquid coming out of the upper packing bed can flow spirally on the conical liquid receiving plate.

A labyrinth seal 6 is provided between the bottom of the conical liquid receiver and distributor 4 and the filler to seal the gas above and below the conical liquid receiver and distributor 4 to avoid gas short circuit.

The static conical liquid receiving and distributor 4 is provided with 4 spiral grooves 5 in the conical tube part, which divides the liquid on the conical tube into 4 parts. There are 4 U-shaped liquid receiving tanks on the upper inner edge of the conical liquid receiving and distributor 4, which are used to send the liquid in the spiral groove to the 4 U-shaped liquid separating tanks of the U-shaped flat plate rotating liquid distributor 7 3.

On the U-shaped flat disk rotating liquid distributor 7, n liquid distribution holes 8 are evenly distributed on the bottom of each U-shaped liquid receiving tank 3, for uniformly distributing the liquid in the U-shaped liquid receiving tank in the circumferential direction. The 4 flat disks corresponding to the 4 U-shaped liquid receiving tanks are evenly distributed in the axial direction of the filler 12, so that the liquid falling on the flat disk is evenly distributed in the inner edge of the filler in the circumferential and axial directions.

The invention makes the liquid form a good initial velocity distribution in the liquid distributor, standardizes the flow path of the liquid in the filler, prolongs the flow path and time of the liquid in the filler, and improves the uniformity of the distribution of the liquid in the filler. The contact area between the phases is increased, the transfer and reaction effect of the filler is strengthened, and the performance of the equipment is greatly improved. The invention can be widely used in the fields of rectification, absorption, chemical reaction, preparation of nanometer materials and the like in petrochemical, pharmaceutical, explosives and other industries.

As shown in Figures 3 and 4, under the action of the pump, the raw material enters the rotating packed bed from the raw material inlet of the rotating packed bed after being metered by the rotameter, and is evenly distributed into quarters by the static liquid distributor and then enters the dynamic U. The four U-shaped liquid receiving tanks of the flat disk rotating liquid distributor 7, through the U-shaped liquid receiving tanks, the liquid is evenly distributed in the circumferential direction and then flow down to the four rotating discs of the dynamic liquid distributor respectively. Spray evenly on the inner side of the filler along the axial and circumferential directions. In the packing, the raw materials are subjected to centrifugal force, packing friction and drag to form liquid films, liquid threads and liquid droplets, and are thrown out from the inside of the packing to the outside, and the liquid leaving the packing is divided equally into The four parts then rotate into the dynamic U-shaped flat disk rotating liquid distributor 7 and the next layer of packing respectively. After several layers of packing, the liquid finally flows out of the rotating packing bed from the liquid outlet of the rotating packing bed and enters the reboiler. The liquid in the reboiler is partially drawn out, and part of it is heated to generate steam. The steam enters the bottom of the rotating packing bed from the gas inlet. Under the action of pressure, it flows from the outside to the inside of the rotating packing, and the gas leaving the packing passes through the dynamic U-shaped flat plate. The rotating liquid distributor 7 is divided into four parts. After mass and heat transfer with the liquid in the liquid distributor, it diffuses from the inside to the outside above the conical liquid receiving plate, and the cross-sectional area gradually increases, and it is connected with the conical liquid receiving plate. The liquid above conducts mass transfer and heat transfer, and then enters the upper layer of packing. After passing through several layers of packing, liquid distributor and conical liquid receiving pan, the steam enters the demister at the top of the equipment, and flows out from the gas outlet after demisting. In order to improve the separation capacity of the equipment, part of the liquid in the partial condenser is returned to the rotary packed bed from the reflux inlet as reflux liquid, and the rest is drawn out as product. The rotational speed of the filler in the rotating packed bed (which determines the strength of the supergravity field) is regulated by a frequency regulator.

Claims (3)

1. A liquid distributor and redistributor for a multi-stage rotary rectification bed, characterized in that it includes a liquid inlet pipe (1), a conical liquid receiver and distributor (4) and a U-shaped flat disk rotating liquid distributor ( 7) Three parts. 2. The liquid distributor and redistributor for multi-stage rotary rectification bed according to claim 1, characterized in that: N liquid distribution tanks (2) are arranged at the front end of the liquid inlet pipe (1), and the conical liquid receiving and The distributor (4) is provided with N spiral grooves (5), and the structure of the U-shaped flat disk rotating liquid distributor (7) includes a flat disk, and the circular inner wall of the flat disk is provided with a U-shaped liquid separation groove (3) , there is a liquid distribution hole (8) at the bottom of the U-shaped liquid separation tank, and there are N U-shaped flat disk rotating liquid distributors (7), which are in the shape of concentric circles, arranged from bottom to top according to the diameter of the flat disk from small to large set up. 3. The liquid distributor and redistributor for multi-stage rotary rectification bed according to claim 1, characterized in that: the positions of the N liquid distribution tanks (2) and the N U-shaped flat disk rotating liquid distribution corresponding to the position of the device (7), the N U-shaped flat disk rotating liquid distributors (7) are respectively connected to the packing (12), and the outer side of the conical liquid receiving and distributor (4) is connected to the rotating packing bed cylinder body connection, the inner ends of the N spiral grooves inside the conical liquid receiver and distributor (4) correspond to the positions of N U-shaped flat disk rotating liquid distributors (7), and the conical liquid receiver and distributor (4) is under N The side is provided with a labyrinth seal (6).

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