SU709156A1 - Gas desorption unit - Google Patents

Description

The invention relates to installations for the desorption of gases from liquids I and can be used in soda production for the regeneration of ammonia and carbon dioxide from bicarbonate liquor. A known unit for the desorption of ammonia and carbon dioxide from a bicarbonate soda production liquor, containing gas-connected ammonia and carbon dioxide strippers, a condenser and a gas cooler, and a reactor-mixer connected in gas to the desorber of ammonia and the carbon dioxide desorber inlet 1. Also known A device for desorption of gases from a bicarbonate mahognik containing ammonia and carbon dioxide desorbers, a gas condenser and a gas cooler, and gas ktor-mixer 2 The disadvantage of these installations is the low productivity due to the high load of carbon dioxide gas desober, which in combination with the high release rate of isodrox dioxide into the vapor-gas phase in the upper part of carbon dioxide stripper leads to its flooding. In addition, the common drawbacks of the known installations are the increased losses of ammonia, calcium oxide and a significant amount of liquid at the outlet of the installation. In the proposed installation containing ammonia and carbon dioxide strippers, a gas condenser and gas cooler connected in series to the reactor-mixer, in order to increase productivity, reduce ammonia losses, the reactor-mixer is connected in gas to the inlet of the gas cooler. With this solution, in the reactor-mixer, part of the ammonia and part of the water from the liquid are evaporated and flow, by desorber of carbon dioxide, into the gas cooler. As a result, the carbon dioxide desorber load is reduced in gas, which allows for an increase in the productivity of the desorption unit. In addition, the ammonia content in the gyrogas stream entering the carbon dioxide stripper and in the fluid at the outlet of this apparatus is reduced. As a result, the equilibrium partial elasticity of vrLerod dioxide in the vapor-gas phase above the liquid in the lower part of this desorber increases, thereby providing for a more complete desorption of carbon dioxide from the liquid and reducing the loss of calcium oxide in the ammonia reactor and desorber. Finally, due to the evaporation of a part of the liquid, its volume at the exit of the installation decreases, as a result of which the loss of ammonia and calcium oxide with the liquid leaving the installation is reduced.

The drawing shows schematically an installation for the desorption of gases.

The installation contains desorbers: 1 - ammonia, 2 - carbon dioxide, successively connected in gas, for example, through a sprinkler 3, then a condenser 4, a gas cooler - 5 and a reactor-mixer 6. The reactor-mixer is connected in liquid with a desorber 2 carbon dioxide output and the inlet of the desorber 1 ammonia, and the gas - with the inlet of the gas cooler 5.

The bicarbonate mother liquor enters the condenser 4, where it is heated by a vapor-gas stream coming from carbon dioxide desorber 2. In this case, part of the carbon dioxide from the liquid is desorbed and removed from the condenser 4 into the total gas stream entering the absorption.

The heated liquid flows into the carbon dioxide dioxide desorber 2, passes down through the desorber; the py 2 and is in contact with the vapor – gas stream coming up from the desorber I of ammonia containing water vapor and ammonia. Carbon dioxide is desorbed by the vapor-gas stream, and the rate and completeness of desorption is the higher, the more equilibrium the partial elasticity of carbon dioxide in the gas above the liquid.

From the bottom of the desorber 2 of the dioxide of the acid, the liquid flows into the reactor-mixer 67 where the calcium hydroxide suspension is also supplied. The ammonium chloride contained in the liquid is decomposed by calcium hydroxide, the liberated ammonia is partially desorbed, and together with the water vapor the short circuit of the blender reactor enters the inlet of the gas cooler 5. PBi increases the pressure on the liquid in the mixer and decreases the rate of ammonia desorption and evaporation of the water . As a result, part of the ammonia contained in the bicarbonate mother is regenerated in the mixer reactor and thus the load on the desorber of ammonia 1 is reduced, and the suspension reactor containing the remaining part of the dissolved ammonia is transferred to the cock. The suspension flows down along the desorber 1 of ammonia downwards, to the top of the apparatus rises a vapor-gas stream consisting of a direct steam introduced into the lower part of the desorber 1 and gradually desorbing from the ammonia suspension. The amount of ammonia entering the carbon dioxide desorber 2 decreases, and consequently, the ammonia content in the carbon dioxide desorber liquid decreases and its partial elasticity rises above the liquid.

The ammonia-free liquid exits the bottom of the desorber 1. The paragas Stream at the outlet of the desorber 1 ammonia is released from the splashes in the spray separator 3, fed into the desorber 2 of carbon dioxide, the condenser 4, the refrigerator 5 and further to absorption. Condensate and: gas condenser 4 flows into carbon dioxide desorber 2, and condensate from gas cooler 5 is fed to

installation for: desorption of gases from ammonia-containing condensates.

Compared with known installations in. proposed productivity increases by 12%, ammonia losses are reduced by

0.12 kg / h and calcium oxide by 194 kg / h, and the output liquid volume is also reduced by 1.6% ...

Claims (2)

1.Shokin I.N., Krasheninnikov S.A. Tekhiologi soda. M., Himi, 1975, p. 65-68, 139-141. 2. Mikulin GI, Polkov IK Distil qi in soda production. L., Goskhimizdat, 1956, p. 57 (prototype). AND Liquid Steam, gas