Graphite porous disc packed tower

Abstract

The invention discloses a graphite porous disc packed tower. One or more layers of packing supporting plates which are horizontally arranged and are made of graphite porous discs are arranged in the packed tower. The graphite porous disc is provided with a plurality of holes which are through up and down, and waste gas and liquid are subjected to mass transfer and exchange of mass and heat in the plurality of holes. The hole is an internal threaded hole with the external diameter larger than the diameter of the liquid drop and the internal diameter smaller than the diameter of the liquid drop; the pressure of the waste gas enables the waste gas to enter the holes and blow off the liquid drops, so that the liquid drops formed by means of surface tension are broken and flow down. According to the invention, the supporting plate and the filler are integrated, so that the manufacturing and maintenance cost is saved, the mass transfer and exchange time of liquid and waste gas is longer, and waste gas cleaning and heat exchange are sufficient.

Description

Technical Field

[0001] The present invention relates to a graphite packing tower, especially a packing tower with mass transfer and heat exchange between gas and liquid. Background Art

[0002] The packing tower is a separation device widely used in the fields of chemical industry, environmental protection, food, etc. Its working principle is mainly based on the gas-liquid contact and mass transfer process. The following is a detailed description of the working principle of the packing tower: Gas-liquid contact: The packing tower increases the contact area between the gas and liquid phases by filling specific packings in the tower, thereby improving the mass transfer efficiency. The gas phase and the liquid phase come into full contact on the surface of the packing, and mass transfer and energy transfer occur.

[0003] Countercurrent operation: Usually, countercurrent operation is adopted, that is, the gas phase flows upward from the bottom of the tower, and the liquid phase flows downward from the top of the tower. Countercurrent operation can make full use of the concentration difference and temperature difference between the gas and liquid phases to improve the mass transfer effect.

[0004] Selection of packing: The selection of packing needs to consider factors such as mass transfer efficiency, pressure drop, corrosion resistance, cost control, etc. Providing the specific surface area of the gas-liquid two-phase contact in the tower is the core part of the packing tower.

[0005] Packing support plate: A component used to support the packing and the liquid held in the tower.

[0006] Surface tension is a property of the liquid surface, which makes the liquid molecules attract each other to form a kind of cohesive force. When the cohesive force between the liquid molecules is greater than the attractive force between the molecules inside the liquid, the liquid droplets tend to form a spherical shape because the spherical shape can minimize the surface area of the liquid, thereby reducing the surface energy.

[0007] It can be seen from the above information that the magnitude of the surface tension is inversely proportional to the size of the liquid droplets. The greater the surface tension, the stronger the cohesive force between the liquid molecules, and the more inclined the liquid droplets are to form smaller spherical shapes; on the contrary, the smaller the surface tension, the easier it is for the liquid droplets to form larger shapes because the smaller liquid droplets have a smaller surface area and require less cohesive force to maintain their shapes.

[0008] The magnitude of the surface tension is related to factors such as the properties of the liquid, temperature, pressure, etc. Generally speaking, polar substances have a greater surface tension, while non-polar substances have a smaller surface tension; liquids with a larger molecular weight also have a greater surface tension; increasing the temperature will reduce the surface tension; increasing the pressure will increase the surface tension of the liquid. Summary of the Invention

[0009] Object of the Invention: To provide a graphite porous disk packing tower that reduces the amount of packing or even eliminates the need for packing, relies on the surface tension of the liquid to extend the gas-liquid mass transfer and exchange time, and improves the exchange effect.

[0010] Technical solution: In the graphite porous disk packed tower of the present invention, there is a liquid inlet above and an exhaust gas inlet below in the packed tower body, a purified gas outlet at the top of the packed tower, and a mixed liquid outlet at the bottom of the packed tower.

[0011] In the packed tower, there is one or more layers of packing support plates made of horizontally arranged graphite porous disks (the inner wall surface of the tower has installation grooves or flanges for facilitating the placement of the packing support plates), and the position of the packing support plate is between the exhaust gas inlet and the liquid inlet.

[0012] The graphite porous disk has numerous holes penetrating up and down. The upper end of the hole is for liquid to enter, and the lower end of the hole is for exhaust gas to enter.

[0013] Mass and heat mass transfer and exchange occur between the exhaust gas and the liquid in numerous holes. The surface area of the exchange is relatively large, and graphite is corrosion-resistant and resistant to high and low temperatures, having the dual functions of both packing and support plate; moreover, it is convenient for cleaning and reuse.

[0014] The thickness of the graphite porous disk is generally relatively large (greater than that of the metal porous disk to meet the strength requirements). Its holes are relatively deep. Preferably, the holes are internal threaded holes (the inner wall has threads, and the pitch of the threads can be designed differently according to requirements). The inner diameter of the thread (the distance between the thread tops at 180° apart is 0.3 mm - 3 mm) is smaller than the diameter of the liquid droplet (the average value of naturally formed liquid droplets), and the outer diameter of the thread (the distance between the thread bottoms at 180° apart) is greater than the diameter of the liquid droplet. The surface tension of the liquid droplet (greater than the self-gravity of the liquid droplet) makes the liquid droplet of this size unable to automatically drip from the hole diameter, and the liquid droplet can hover in the hole with internal threads, extending the duration of mass transfer and exchange.

[0015] The pressure of the exhaust gas enables the exhaust gas to enter the hole and blow the liquid droplet to form smaller liquid droplets, causing the liquid droplets formed by surface tension to break and drip or flow down.

[0016] Preferably, the product of the air pressure of the exhaust gas and the cross-sectional area of the inner diameter of the thread of the hole ≥ the surface tension of the liquid droplet - the self-gravity of the liquid droplet, that is, the air pressure can blow the liquid droplet and make it drip from the hole.

[0017] The temperature of the exhaust gas is higher than that of the liquid. In a packed tower with 2 - 6 layers of multi-layer packing support plates, the temperature of the liquid exchanged in the lower packing support plate is higher than that of the adjacent upper layer, the surface tension of the liquid droplets in the lower layer is smaller than that of the adjacent upper layer of liquid droplets, and preferably, the hole diameter of the lower layer is smaller than that of the adjacent upper layer.

[0018] Beneficial effects: The present invention combines the support plate and the packing into one, saving manufacturing and maintenance costs.

[0019] The mass transfer and exchange time between the liquid and the waste gas is relatively long, and the waste gas cleaning and heat exchange are sufficient. By relying on the surface tension of the liquid and the pressure of the waste gas to control the exchange process, the mass transfer and exchange duration and quality between the gas and the liquid can be freely designed and determined. In the present invention, holes with internal threads are adopted, which is a kind of anti-traditional thinking (traditionally, it is required that the flowing holes be as smooth as possible), significantly increasing the droplet suspension time (each thread of the screw stops once), which is beneficial to heat and mass exchange and finally enables the droplets to drip to complete the exchange process.

[0020] The packing support plate is made of graphite, corrosion-resistant and resistant to high and low temperatures, and is suitable for the recovery and purification of many waste gases (such as acidic waste gases).

[0021] The generated mixed solution can be subsequently processed to recover and utilize useful media therein; the tail gas after cleaning is relatively clean, and useful gases can be recovered and utilized, reducing environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the bottom view of a packing support plate of the present invention; Figure 2 is Figure 1 the perspective view of the three-dimensional structure; Figure 3 is the schematic diagram of a three-dimensional structure of the present invention; Figure 4 is another schematic diagram of the three-dimensional structure of the present invention.

[0023] In the figure, 1-graphite porous disk (11-upper surface of the disk, 12-lower surface of the disk); 2-purified gas outlet; 3-waste gas inlet; 4-hole (41-inner diameter of the thread, 42-outer diameter of the thread); 5-mixed liquid outlet; 6-liquid inlet. DETAILED DESCRIPTION OF THE INVENTION

[0024] Example 1: As Figure 1 shown in the graphite porous disk packing tower, there is a liquid inlet 6 above and a waste gas inlet 3 below in the packing tower body, a purified gas outlet 2 at the top of the packing tower, and a mixed liquid outlet 5 at the bottom of the packing tower.

[0025] As Figure 3 shown, there is a packing support plate made of a horizontally arranged layer of graphite porous disks 1 in the packing tower, and the position of the packing support plate is between the waste gas inlet 3 and the liquid inlet 6.

[0026] The described graphite porous disk 1 has numerous holes 4 (internal threaded holes 4 with a diameter of 0.5 mm - 1 mm) that penetrate vertically. The upper end 41 of the holes is for liquid to enter, and the lower end 42 of the holes is for waste gas to enter. Mass and heat transfer occur between the waste gas and the liquid in the numerous holes 4. The liquid droplets are blocked and suspended by several threads of the internal thread, and finally, relying on the gravity of the liquid droplets themselves, they can slowly drip into the solution chamber step by step.

[0027] Example 2: As Figure 1 , 2 shown in the graphite porous disk packing tower, the packing tower body has a liquid inlet 6 at the upper part, a waste gas inlet 3 at the lower part, a purified gas outlet 2 at the top of the packing tower, and a mixed liquid outlet 5 at the bottom of the packing tower.

[0028] As Figure 4 shown, there is a packing support plate made of three horizontally arranged layers of such graphite porous disks 1 in the packing tower.

[0029] The described graphite porous disk 1 has numerous holes 4 that penetrate vertically. The upper end 41 of the holes is for liquid to enter, and the lower end 42 of the holes is for waste gas to enter. Mass and heat transfer occur between the waste gas and the liquid in the numerous holes 4.

[0030] The inner diameter 41 of the thread of the hole is (0.3 mm - 0.5 mm), which is smaller than the diameter of the liquid droplet. The surface tension of the liquid droplet makes it impossible for a liquid droplet of this size to automatically drip from the inner thread aperture. The outer diameter 42 of the thread is larger (0.6 mm - 1.0 mm), which is larger than the diameter of the liquid droplet.

[0031] The liquid enters the packing tower from the liquid inlet 6. The pressure of the waste gas entering from the waste gas inlet 3 can break the liquid droplets dripping on the packing support plate, causing the liquid droplets formed by surface tension to break into small liquid droplets, which quickly drip into the mixed solution chamber at the bottom through the holes 4 and are led out from the mixed solution outlet 5. The gas washed by the liquid is discharged from the purified gas outlet 2 at the top of the tower.

Claims

1. A graphite porous disk packed tower, wherein the packed tower body has a liquid inlet (6) at the top and an exhaust gas inlet (3) at the bottom, a purified gas outlet (2) at the top of the packed tower, and a mixed liquid outlet (5) at the bottom of the packed tower, characterized in that: A packing support plate made of one or more layers of graphite porous disks (1) arranged horizontally in a packed tower is located between an exhaust gas inlet (3) and a liquid inlet (6); The graphite porous disk (1) has a plurality of holes (4) which are transparent from top to bottom. The holes are internal thread holes. The upper end (41) of the hole allows liquid to enter, and the lower end (42) of the hole allows exhaust gas to enter. Exhaust gas and liquid exchange mass and heat in the plurality of holes (4). The outer diameter of the thread of the hole is larger than the diameter of the droplet, and the inner diameter of the thread is smaller than the diameter of the droplet. The surface tension of the droplet prevents the droplet of this size from automatically dripping from the hole, and can hover in the hole for a long time.

2. The graphite porous disk packed tower according to claim 1, characterized in that: The pressure of the exhaust gas can break the droplets to form smaller droplets, the diameter of which is smaller than the inner diameter of the thread, causing the droplets formed by surface tension to break or flow and drip.

3. The graphite porous disk packed tower according to claim 2, characterized in that: The product of the exhaust gas pressure and the cross-sectional area of ​​the inner diameter of the hole thread is ≥ the surface tension of the droplet - the droplet's own gravity.

4. The graphite porous disk packed tower according to claim 1, 2 or 3, characterized in that: In a packed tower using 2-6 layers of multi-layered packing support plates, the hole diameter of the lower layer is smaller than the hole diameter of the adjacent upper layer.

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