RU2265170C1 - Mode of regeneration of a drying agent of convective dryers - Google Patents

Abstract

FIELD: the invention refers to technique of controlling temperature of air or gases for drying solid materials or objects.

SUBSTANCE: new in the mode of regeneration of a drying agent of convective dryers which includes heat exchange between the drying agent and liquid sorbent for changing temperature of the drying agent and recovery of the sorbent's concentration is that in the process of heat exchanging between the drying agent and the liquid sorbent the sorption heat is used for heating the drying agent fed into the dryer and recovery of sorbent's concentration is carried out by multistage evaporation at putting heat exchange between sorbents of different concentrations into effect. At that the movement of the drying agent in the dryer is made in closed contour.

EFFECT: the invention must ensure increasing degree of using of the heat of the drying agent at the expense of using the sorption water steam heat.

1 dwg

Description

The present invention relates to techniques for controlling the temperature of air or gases for drying solid materials or objects.

A known method of utilizing the thermal energy of exhaust air, comprising cooling the exhaust air with transferring heat from it to the primary and secondary heat carriers and heating the supply air with transferring heat to it from the primary and secondary heat carriers, wherein transferring heat from the exhaust air to the primary and secondary heat carriers and transferring heat from the primary and secondary coolant to the supply air is carried out simultaneously using contact and surface heat transfer and [AS No. 1525409, F 24 F 3/147, 1989. B.I. No. 44].

The disadvantages of this method are its inapplicability for the utilization of the heat of the drying agent of convective dryers due to the inability to restore the sorbent due to the high moisture content of the drying agent. The inability to use the heat of sorption of water vapor from a drying agent to heat a fresh drying agent.

An object of the invention is to increase the degree of utilization of the heat of the drying agent by using the heat of sorption of the water vapor contained in it and the possibility of using the method for utilizing the heat of the drying agent of convective dryers.

The problem is achieved in that in the method of regenerating the drying agent of convective dryers, including heat exchange between the drying agent and the liquid sorbent to change the temperature of the drying agent and restoring the concentration of the sorbent, it is new that in the heat exchange process between the drying agent and the liquid sorbent the sorption heat is used for heating the drying agent supplied to the dryer, and restoring the concentration of the sorbent is carried out by multi-stage evaporation during heat exchange between sorbents of various concentrations, with the movement of the drying agent in the dryer produce a closed loop.

The technical result consists in a more complete use of the heat of the drying agent due to the release of heat of sorption of the water vapor contained in it and the possibility of using the method for utilizing the heat of the drying agent of convective dryers.

The drawing shows a diagram of the proposed device for implementing the method of regeneration of the drying agent of convective dryers.

A device for implementing the method consists of an absorber 3 connected by an air duct 9 through a fan 2 to a dryer 1, two casings 6 and 7 of the evaporator station, connected to the absorber 3 through a heat exchanger 5 and to each other through a heat exchanger 14, as well as a heater 4 for additional heating of fresh a drying agent connected by pipelines 10 and 11 to the second housing 7 of the evaporation station and barometric condenser 8, respectively.

A method of regenerating a drying agent is as follows.

From dryer 1, fan 2, the drying agent through the duct 9 enters the absorber 3, where it is heated and sorbed in it with a concentrated sorbent solution, as a result of which the drying agent is dehydrated and heated due to the heat of sorption of water vapor. Next, a weak solution of the sorbent by the pump 13 through the filter 12 is fed into the heat exchanger 5, where it is heated with a strong solution coming from the second building 7 of the evaporation station, which is heated by secondary steam from the first housing 6 of the evaporation station. Then, the sorbent solution is sequentially processed in the first 6 and second 7 buildings of the evaporation station, where its concentration is restored, and sent to the absorber 3, and the effluent from the housing 6 heats the solution supplied to the housing 6 in the heat exchanger 14. Secondary steam from the second housing 7 is evaporated station through pipeline 10 is directed to the heater 4, where it is used for additional heating of the drying agent supplied to the dryer, and steam and condensate are sent through pipeline 11 to the barometric condenser 8.

The advantage of the method of regeneration of the drying agent in comparison with the known is that its use allows to ensure:

- the possibility of its use for using the heat of the drying agent of convective dryers;

- more complete use of the heat of the drying agent through the use of heat of sorption.

Claims (1)

A method of regenerating a drying agent of convective dryers, comprising heat exchange between a drying agent and a liquid sorbent to change the temperature of the drying agent and restoring the sorbent concentration, characterized in that the heat of sorption is used to heat the drying agent supplied to the dryer during heat exchange between the drying agent and the liquid sorbent, and restoration of the sorbent concentration is carried out by multi-stage evaporation during heat exchange between sorbents of various concentrations, while movement of the drying agent in the dryer produce a closed loop.