SU209964A1 - INSTALLATION FOR BLEACHING OF CELLULAR OR SIMILAR WEIGHT - Google Patents

Description

Installations for bleaching pulp or the like by chlorination are known, including an adsorber column, a disintegrant bunker, a screw press and a discharger. However, such plants do not provide uniform chlorination, and the workflow is long.

The purpose of the invention is to provide the required temperature of the gas mixture and intensify the bleaching process. This is achieved by performing an installation with a recirculation system for a gas mixture comprising an adsorber column, a fan that takes a gas mixture from the upper part of the latter through a cyclone and a heat exchanger and injects it into the lower part of the adsorber column, and with a pre-chlorination chamber located below the gas inlet pipe used for gas injection mixes.

The drawing schematically shows the described installation.

The installation includes a feeder screw press 1, a disintegrator hopper 2, an adsorber column 3, a gas mixture recirculation system with a control valve 4, a cyclone 5, a heat exchanger 6j dochlorination chamber 7, an unloading device 8, a pool 9 with a bash mixer and an exhauster / L

dry and fed into baking powder. The loosened mass in the form of separately flying flakes is lowered into the adsorber column and its fall is slowed down by countercurrent of the gas mixture circulating in the system. The rate of lowering of the mass is controlled by a damper 4. The gas mixture is brought to the column above the final chlorination chamber, so the mass adsorbed chlorine drops out of the circulation flow and accumulates in the chamber. The height of the mass layer in the chamber can be adjusted within wide limits, since the unloading device has an infinitely variable drive. In this way, the mass residence time in the after-chlorination chamber can be adjusted.

After unloading, the mass in the pool is diluted to a concentration of 3-4% and pumped out with a pump for further processing. Since the chlorination process proceeds with heat generation, the gas mixture is cooled in the heat exchanger to provide the required temperature, after which the mixture enters the adsorber column inlet, cooling the chlorinated mass.

The chlorination process in the adsorber column proceeds when the mass is partially suspended, so there is an active mass and heat exchange, which intensifies the process and leads to the stabilization of the quality of the chlorinated mass.

In order to reduce the dissolution of free chlorine in the water, which dilutes the mass when it enters the pool, an exhauster is installed, which can supply the sucked gas mixture to a special absorber; the fines are caught by the cyclone.

Subject invention

Plant for bleaching pulp or similar mass by chlorinating it, including an adsorber column, bunker blender, screw-press and unloading device, characterized in that, in order to intensify and select the optimal parameters of the bleaching process, the unit is made with a gas recirculation system a mixture comprising an adsorber column, a fan, which takes a gas mixture from the upper part of the latter through a cyclone and a heat exchanger and injects it into the lower part of the adsorber column, and with a dochlorination chamber located below the nozzle that serves to inject the gas mixture.