CS259197B1 - Drier with spontaneous ventilation - Google Patents

Abstract

The dryer is designed for gradual drying with subsequent spontaneous ventilation of the part the dried material where it was just broken forced drying. Behind the entry closures of the drying air from the longitudinal the feed ducts are transverse air ducts before their outlets under the layer of material in the oven open access closures atmospheric air.

Description

The present invention relates to a self-ventilated dryer, in particular for grains.

In the case of grain driers, the so-called step-by-step drying has recently emerged, consisting in the optional and gradual introduction of a warm drying air from the longitudinal inlet duct into the set of transverse drying ducts under the grain layer in the building. · this is advantageous from the energy point of view and some improvement of the drying quality compared to the pre-casting state, but this process still does not achieve an even moisture distribution in the grain layer where the grains deposited closer to the drying air outlet from the transverse channel are warmer and drier and the grain away from the channel, i.e. at a higher embankment level, cooler and more humid · At the gradual drying pause, the warm air supply is interrupted and to dry in the next place, then practically only the temperature of the lower layer drops and the humidity of the upper layer does not decrease too much ·

This disadvantage is overcome by the self-ventilating dryer according to the invention, characterized in that the air inlet closures of the longitudinal inlet drying duct are provided with openable atmospheric air vents before they exit below the material layer in the drier.

259197 ·

The self-ventilated oven according to the invention allows a uniform temperature and humidity distribution throughout the height profile of the grain layer after interrupting the drying of this part of the material. This is achieved by self-ventilation / without any additional energy requirement. The invention provides a further improvement in the drying quality and the energy savings achieved by utilizing the heat accumulated upon interruption of the drying air supply in the backsheet.

An exemplary embodiment of an oven according to the invention is shown in the accompanying drawing, wherein FIG. 1 is a cross-section of the dryer and FIG. 2 is a plan view of FIG.

The drier 1 with the material layer 2 is provided with a longitudinal supply drying duct 3 connected to the hot-air unit 4. Transverse air ducts 5 separable from the longitudinal supply drying duct 3 through inlet shutters 6 and introduced below the material layer 2 are connected to the longitudinal supply duct 3. the transverse air ducts 5 are separable from the ambient atmosphere by opening the ventilation shutters X arranged downstream of the inlet shutters 6, but before the outlets 8 of the transverse air ducts 5 below the material layer 2 in the dryer 1 "

The dryer according to the invention is operated as follows:

For the supply of drying air, the inlet shutters 6 of the respective group of transverse air ducts 5 are opened, and the ventilation shutters 7 of this group of transverse air ducts 5 are closed. After a certain drying time, by closing the inlet shutters 6, the drying air supply from the longitudinal supply duct 3 from the hot-air aggregate 4 is interrupted and the inlet shutters 6 of the other group of transverse air ducts 5 are opened, where forced drying is transferred. In the group of transverse air ducts 5 where forced drying has just ended and where the inlet shutters 6 have closed, the ventilation shutters 7 now open.

AND

- 3 *

By naturally rising warm dry air from the lower warm layers to higher colder and humid ones, air is sucked through the open air closures 7 from the ambient atmosphere, permeates the material layer where it cools the bottom layer and transfers heat to the upper layer. the layer profile while at the same time some drying of the upper layer and a favorable cooling of the lower layer of the material

Claims (1)

An oven with spontaneous ventilation of the dried material by accessing atmospheric air through an inlet opening where transverse air channels introduced under the material layer in the dryer are connected to the longitudinal air supply drying channel with the hot-air aggregate, characterized in that the transverse air channels (5) are between them (1) under the material layer (2) in the dryer (1) and the inlet closures (6) of the drying air inlet from the longitudinal air inlet duct (3) provided with openable air closures (7) of the inlet air.