control of the vacuum generated by the roll 23 particularly at the beginning stage of drying higher vacuum is required especially for the runnability component of the pocket space blow box and the control of vacuum generated by the roll is also more useful in this case at the final stage of drying it may be preferable to use a box according to fig8 or even of fig4 the paper being then drier and easier to control fig7 and 8 show schematic views of dryer groups r adapting single fabric run arrangements with rolls 23 according to the invention located as turning rolls and pocket spaces t equipped with a blow box 20 being used in connection therewith the top row dryer cylinders are indicated with reference number 37 and the dryer fabric and its lead and guide rolls are referred to with numbers 38 and 39 respectively fig7 shows an embodiment in which in the pocket spaces t of a dryer group r adapting a single fabric run arrangement there is located a blow box 20 c which corresponds primarily to the embodiment illustrated in fig6 allowing to optimize the vacuum production of rolls 23 considering the position of the group in the dryer section fig8 shows an embodiment in which the blow box 20 located in the pocket spaces t corresponds primarily to the embodiment illustrated in.