1. packing tower
The utility model is composed of a shell, a filling, a filling support, a liquid distributor, an intermediate support and a re distributor, a gas and liquid inlet and a nozzle, etc. the shell of the tower is made of metal materials and can be made of plastics.
The filling is the core of the packed tower, which provides the contact surface of the gas-liquid two-phase in the tower, and the structure of the packing and tower determines the performance of the column. Fillers must have larger specific surface, higher void content, good wettability, corrosion resistance, mechanical strength, low density, low price, etc.. The commonly used packing with Rasching rings, Bauer ring, arc saddle and Intalox saddle, new media development after 1980s as the QH - 1 type flat ring packing and 84 inner ring, hedgehog shaped filler metal plate, corrugated plate packing, packing, regular grid filling, provides the basis for the packing tower advanced design.
A packed column suitable for rapid and transient absorption processes; used for gas purification. The tower has the advantages of simple structure, easy fabrication of corrosion resistant material, gas-liquid contact area, the contact time is long, strong adaptability of gas tower, tower resistance, pressure loss is 300 700Pa, and compared the plate tower volume small, empty tower gas velocity is 0.5 1.2m/s, the formation of flooding gas velocity 6, spray density 8m3/ (m2, H) to ensure that the filler wetting, liquid gas ratio control in 2 - 10L/m3. The packed tower is not suitable for dealing with the flue gas with large dust content, and the problem of uneven gas-liquid distribution in the tower should be overcome during the design.
2. plate tower
The tower is equipped with layers of trays in the tower, and the liquid enters from the top of the tower. The gas enters the bottom of the tower and the gas-liquid mass transfer and heat transfer process are carried out on each tray. There are many kinds of plate towers. Can be divided into two categories: one is the downcomer, such as bubble tower, sieve plate tower, float valve tower, S tower, one-way flow plate tongue plate tower, floating spray tower; the other is through flow type plate tower, such as the turbogrid plate (shower trays tower), corrugated turbogrid tower, diamond slant hole plate tower, short turbogrid tower etc..
(1) sieve plate tower;
The diameter of the sieve usually takes 5 to 10mm, and the total area of the sieve occupies 10% to 18% of the sieve plate area. In order to make the plate liquid layer on a uniform thickness, is provided with a sieve overflow weir, the liquid layer thickness is about 40Mn, the wind screen empty tower is about 1 ~ 3.5m/s, sieve holes gas velocity of 6 ~ 13m/s, 300 ~ 600Pa per layer plate resistance. The sieve plate tower has the advantages of simple structure, large processing capacity and capable of dealing with dusty gas. The deficiency is that the sieve holes are blocked and the cleaning is more troublesome. The installation requirements of the tower are strict, the tray should be kept horizontal and the operation flexibility is smaller.
(2) cable trays
Cable trays is another form of sieve plate tower. Inclined hole width 10 ~ 20m, length 10 ~ 15mm, high 6mm. The air velocity of the empty tower is usually 1 to 3.5m/s, and the velocity of the sieve hole is 10 ~ 15m/s. The gas ejected from the horizontal oblique hole, hole direction of two adjacent holes in staggered liquid through the overflow weir for to tray (weir height 30mm), and the airflow direction vertical flow, turbulence caused by the height of the gas to liquid surface is constantly updated, full gas-liquid contact, better mass transfer effect, high purification efficiency, at the same time gas processing dust, easy to plug, each layer plate resistance is about 400 ~ 600Pa. The tower structure is more complex than the sieve plate tower, difficult manufacture, installation requirements strictly, prone to drift.
(3) venturi absorber
The venturi tube absorber is usually composed of Venturi tube, a sprayer and a cyclone separator, liquid spray operation will flow to the venturi throat, the airflow speed is 60 ~ 100m/s, 100m3/min waste gas treatment liquid spray amount is 40L/min. The venturi absorber is simple in structure, small in equipment, small in space, high in gas velocity, large in handling capacity, good in gas-liquid contact and easy in mass transfer. It is especially suitable for trapping small particles in the air stream. But because of the gas liquid cocurrent flow, the contact time between gas and liquid is short, so it is not suitable for the gas-liquid absorption which is difficult to dissolve or slow in reaction. Moreover, the pressure loss is large (800 ~ 9000h), and the energy consumption is high.
3. turbulent ball tower
It is a special form of packed tower, in which the packing in the tower is in motion to strengthen the absorption process. Put a certain number in the tower gate plate between the light ball filler (diameter 29 38mm), from the top of the tower under the spray absorber, wet ball surface, gas enters from the bottom of the tower, the ball is blown turbulence due to rotation, full contact of the gas liquid solid phase, small liquid film on the surface of constantly updated, increasing the absorption driving force. The absorption efficiency is improved.
The tower is easy to manufacture, install and maintain. It can change the range of operation with small balls of different sizes and qualities. The tower has large air handling rate, air tower velocity 1.5 - 6.0m/s, spraying density 20 - 110m3/ (m2, H), pressure loss 1500 - 3 800Pa, and it can also deal with dusty gas. Its disadvantage is that plastic pellets can not withstand high temperatures, small balls easy to crack (generally 0.5 - 1 years), often need replacement, high cost.