METHOD OF CONTROLLING PROCESS OF BUTYL RUBBER DRYING Russian patent published in 2014 - IPC C08F210/12 C08F236/06 G05D27/00 C08C3/00 

FIELD: chemistry.

SUBSTANCE: method consists in the supply of the wet butyl rubber crumb into an expeller, mixing in the expeller, realisation of the process of throttling, obtaining the dried rubber crumb. The preliminarily dried in the expeller crumb is supplied into an expander, after the expeller division of the crumb flow into two flows is carried out in a ratio of 9:1, one flow in a quantity of 90% of the total flow is supplied directly to the expander input, the second flow in a quantity of 10% of the total flow is irrigated on a transporter with a water solution of a drying agent, as such used is ammonium hydrocarbonate (porofor), synthesised by mixing separate flows of ammonium, carbon dioxide and water at a temperature from 0°C to +5°C in a packed column. The solution of the drying agent ammonium hydrocarbonate is cooled in a refrigeration circuit to a temperature of -3÷0°C, used in irrigation of the second flow of the rubber crumb pulp, to reduce the temperature of the rubber crumb on the output from the transporter to a temperature of +10÷+13°C. The second flow is supplied to the expander input to mix with the first flow of the crumb. Further rubber drying to the moisture content of 0.01-0.05 wt % is carried out. Control over the drying process is performed by a value of difference of temperatures of the drying agent ammonium hydrocarbonate solution before and after irrigation with it of the rubber crumb by means of an automated control system (ACS), which analyses information from sensors of the solution consumption and temperature: readings of the sensors of temperature of the drying agent ammonium hydrocarbonate solution are taken before and after irrigation with it of the rubber crumb, difference of temperatures is analysed, readings of flowmeters of consumprion of the drying agent ammonium hydrocarbonate solution are taken before and after irrigation with it of the rubber crumb, difference of the solution consumption is analysed. In case of deviation from a programmed value, the ACS sends controlling commands to change the temperature of the drying agent by changing refrigerant consumption in a refrigeration circuit. The controlling commands are sent to a circulation pump to change consumption of the flow of the drying agent ammonium hydrocarbonate solution, supplied for irrigation of the rubber crumb until the specified temperature of the crumb is achieved.

EFFECT: reduction of energy consumption, increased safety due to the absence of the process with an application of high pressure, increase of rubber quality.

6 ex, 3 dwg, 2 tbl