Automatic cleaning systems are also known in the field of cleaning production piping
, tanks and receptacles by stationary nozzles emitting a suitable cleaning fluid being incorporated in the vessels to be cleaned. Such stationary nozzles cannot be put to use in belt dryers. Thus, in conventional belt guidance arrangements there is hardly any possibility, nor sufficient space for providing a means of automatic cleaning. Furthermore, very large surface areas need to be cleaned in a mesh belt dryer which would necessitate a correspondingly high number of stationary nozzles. Apart from this, the drying process would be obstructed by such an array of nozzles, since the stationary nozzles would need to be included in the drying chamber and stay there during drying. In addition, stationary nozzles require a relatively large amount of cleaning agent.