Mathematical models for washing and dewatering zones of a rotary vacuum filter

276-280<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Brown stock washing is an important stage in pulp and paper industry and infact plays a key role for reducing environmental problems at one hand and helps to get more concentrated black liquor on the other. Usually, it is carried out by using multiple rotary vacuum washers. For better control of the process a mathematical model pertinent to brown stock washing system involving all the parameters needs to be developed because a theoretical analysis may prove helpful to achieve the required objective. Keeping this in view, the general model for cake washing zone of a brown stock washer has been developed. The general model has been simplified by assuming that the Longitudinal dispersion coefficient (DL) is zero as in the case of Perron and Lebeau4.This model has been solved to find out the concentration of different streams. The efficiency parameters have been given in terms of fundamental parameters. To calculate the performance of the rotary vacuum washer the data of Han and Edwards8 have been used. The results are in close agreement with their predictions.</span