Device with a channel for drying parts,preferably wooden parts

© Start of patent period · 1976 07 15 Longest possible duration:

© Issued on: 1977 04 12 © inventor:

© dependence:

OL · 335 918 © Pamphlets considered to delineate the prior art:

DT-PS969632, OE-PS245498, OE-PS283216, OE-PS2 / 2206-2

Nr.335918

The invention relates to a drying installation, in particular a drying channel, for passing parts to be dried, mainly pieces of wood, which are arranged in at least two stacks or stack groups on a conveying device which advances the stacks, in particular stepwise, in the longitudinal direction of the installation. wherein the system for forming different climatic zones for individual stacks or stack groups is subdivided by at least one intermediate space into at least two longitudinal sections, which of gaseous medium, in particular air, with respect to the feed direction in the DC or Countercurrent flows through separate circuits, wherein in addition to a receiving space for a stack or a stack group is provided approximately the length of the receiving space corresponding return channel for gaseous medium to which a fan assembly or the like. for circulating the gaseous medium, measuring devices for the temperature of these controlled heaters and means for regulating the medium flow rate, eg Control valves or the like., Are assigned, wherein the drying plant openings for the supply and discharge of the gaseous medium and a spraying device for treatment liquid, in particular water.

In a known drying plant of this type (see Austrian Pat. No. 2,445,498), two receiving chambers, which have different climatic zones, are separated from one another by a screen which can be removed when the stacks are being transported. The supply of the gaseous drying medium to the mentioned receiving spaces takes place hiebei from the outlet side of the drying channel over a length in its length approximately immediately after the screen receiving space corresponding first return channel, which is in communication with both considered receiving spaces. In the area of ​​the screen, the medium flow supplied via the aforementioned first return channel is divided into two partial streams, one of which flows countercurrently with respect to the feed direction of the dry material, the receiving space located behind the screen in direct current and the other in front of the screen receiving space. In addition, a further return channel for the drying medium is provided, which extends from the front end of the front of the screen receiving space to the inlet side of the first return channel. In this first return channel so the two receiving spaces associated medium streams are combined. To circulate the dry medium, a fan is provided on the inlet side of the first return channel. The action on the climatic zones is carried out partly by means of heaters, which are arranged in the first return channel and partly via control valves, which are located on the outlet side of both return channels, being provided at the outlet side of the first return channel only at the mouth to the existing behind the screen receiving space flaps , The control of the heaters via directly arranged next to these thermostats. The control of the provided at the outlet end of the first return channel control valves via a provided on the inlet side of the second return channel thermostat, whereas the control of the provided at the outlet end of the further return channel control valves is carried out by a arranged in the first return channel thermostat. A disadvantage of this known drying plant that despite a relatively large amount of control equipment and despite the presence of a screen between the two climatic zones often not sufficiently differentiated control of climates is possible because the two receiving spaces associated medium streams on their common path through the first Strongly influence feedback channel. Another disadvantage is the fact that there must be provided for the screen located between the two recording spaces an operating device, which makes the system more expensive. Another disadvantage is that only at the inlet side of the receiving space located in front of the screen, a spraying device is provided, whereby the differentiation of the air conditioning is further complicated.

Furthermore, drying systems are known (see Austrian Pat. No. 2,772,206 and No. 283216), which are divided by at least one space in at least two longitudinal sections, which are flowed through by gaseous medium, in particular air, wherein adjacent to the receiving spaces for the stack or Stack groups Rückfiihrkanäle are provided whose length corresponds to the length of the individual receiving spaces for the stack or stack groups and which a blower or the like. for circulating the gaseous medium, measuring devices for temperature and humidity, a heating device and, optionally, a spraying device for treatment liquid are assigned. A disadvantage of these known drying systems that a differentiated control of the individual climates is not possible because all measuring devices for temperature and humidity are arranged approximately at the same distance from the ends of the drying plant, so are in a single climate zone.

From German patent no. 969632 a device for conditioning wood, veneers, wood pulp, board and other materials is known, in which the treatment air is circulated transversely to the conveying direction of the material to be treated. Facilities are provided for the different treatment stages, by means of which the temperature and humidity of the air are generated controllably and adjustably. Outside the air conditioning duct is an air conditioning unit with a fan for the preparation and introduction of the treatment air in the different duct zones. For this purpose, the air conditioning and fan are connected by piping to the channel. Flaps are provided for setting and adjusting the air supply. In addition, control devices (flaps), heaters and

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Nr.335918

Moistening devices provided. A disadvantage of this known device is that to the individual

Channel zones run stubs for the supply and discharge of air to common, with a single

Climate device connected main lines are connected, which is why often not sufficiently differentiated

Regulation of the climatic zones is possible.

The aim of the invention is to avoid the disadvantages mentioned and to provide a drying plant of the type mentioned, in which an optimal control option for the different climates is guaranteed.

This object is achieved according to the invention that provided for mutually uninfluenced control of the individual climatic zones in each receiving space associated return channel own thermostat, controlled by this heater and means for controlling the medium flow rate, eg flaps and a measuring device for moisture and a spray device controlled by it are.

These measures have the following advantages in particular:

1. Possibility of simultaneous, differentiated or different treatment of dry material with different initial moisture and with different dimensions,

Second Possibility of extremely differentiated treatment of different dry material in receiving rooms with low temperature differences and low differences in humidity,

Third Possibility of forming any desired drying process required climate over the length of the drying plant,

4th Possibility to control the throughput of the desiccant from a value of zero to full blower capacity for one or individual stacks or stack groups,

5th very low energy consumption due to optimal dosing possibility of the individual drying factors (temperature, air humidity, air velocity at the surface of the dry material) for each climate zone.

For longer drying channels mutually unaffected regulation of the individual climates according to a preferred embodiment of the invention is particularly well ensured that in the presence of two or more divided by a gap pairs of receiving spaces for each pair of receiving spaces both at least one separate opening for the Supply as well as at least one separate opening for the discharge of the gaseous medium to are arranged from the drying plant in the region of at least one of the ends of each return channel.

A particularly favorable control option and a particularly favorable medium flow result in a further preferred embodiment of the invention in that in the presence of a common fan arrangement for the receiving spaces or return ducts of two adjacent stack or stack groups, the control valves or the like. are arranged in the blower adjacent areas of the return channels.

The medium flow rate can be controlled particularly well according to a further preferred embodiment of the invention, when the openings for supplying and discharging the gaseous medium are provided between the adjacent control devices for the medium flow rate of two successive return channels.

The invention will now be explained in more detail with reference to the schematic drawings. 2 shows a horizontal section through the drying installation according to FIG. 1, FIG. 3 shows a vertical longitudinal section through a second embodiment of a drying installation, FIG. 4 shows a horizontal section through a third Embodiment of a drying plant and Figure 5 is a vertical longitudinal section through a fourth embodiment of a drying plant.

According to FIGS. 1 and 2, two stacks or stack groups -2 and 3- are contained in a housing -1- of a drying installation -la- designed as a drying channel. On the exit side of the drying plant is an already dried stack -4-. The stacks are introduced through an entrance gate -5- into the drying channel -la and transported out through an exit gate -6- out of the drying channel -la. The arrows -F and F'- indicate the conveying direction of the stack -2, 3 and 4 with respect to the drying channel again. The conveyor for the stack is formed in the present case by transport rollers -7-, on which there are pallets or support plates -8- for the stack -2, 3 and 4-. The conveying device pushes the stacks -2, 3 and 4-, in particular stepwise, in the longitudinal direction of the drying channel -la-, the drying channel being subdivided by a gap -9- into two longitudinal sections, that of gaseous medium, in particular air, in the sense the arrows -U- are flowed through. In this case, the stacks -2 and 3- located in receiving spaces of channels -10, 11- are surrounded by the return of the gaseous medium, which blowers -12- or the like. for circulating the gaseous medium, measuring devices for temperature and humidity -13 or 14-, a heating device -15- as well as a spraying device -16- for a treatment medium, in particular water, are assigned. Furthermore, the drying channel has openings -17 and 18- for the supply and discharge of the gaseous medium.

Nr.335918

The invention consists in the fact that for mutually uninfluenced control of the individual climates in each receiving space associated return channel -10,11- its own thermostat -13-, controlled by this heater -15- and means for regulating the medium flow rate, eg

Flaps --19 and a measuring device 14 for moisture and one of them controlled

Spraying - 16- are provided. In the opening -18- for discharging the gaseous medium, a control valve -20- is provided. At the top of the stack -2 and 3- are cover plates -21 and 22-, which together with the housing -1- the return channels -10 and 11- form. By the means for regulating the medium flow rate of the return channel can be narrowed in any way, fully open or completely locked.

3 schematically shows a drying channel -1'- with several stacks or stack groups -2 'and 3' -, wherein like parts are provided with similar reference numerals. With this arrangement, it is possible to produce any desired or desired drying zone or climatic zone over the length of the drying channel, since several climatic or dry areas can be formed. In this figure, the measuring devices, the heaters and the spraying devices are not shown for the sake of clarity.

4 shows a drying duct with blowers -12 "- whose axis is horizontal and whose impeller is located in a vertical plane. Also in this figure, similar parts are designated by like reference numerals. The return channels -10 "and 11" - are in this embodiment, not above, but on both sides of the stack -2 "and 3" - arranged and bounded by vertical plates -21 "and 22" -. Accordingly, the openings for the supply and removal of the gaseous medium, the measuring, heating and spraying devices -13 ", 14" or 15 "or 16" - on either side of the stack of -2 "and 3" - stack row formed arranged.

In the arrangement of Figure 4, each area of ​​the stack can be differentiated and individually dried, as a gradation ability of the dry or climatic zones both in transverse and in

Longitudinal direction of the drying channel is possible.

5 shows a drying channel, which substantially corresponds to the drying channel shown in Fig.l, but instead of a common fan or a common fan arrangement for the two stacks has separate blower or blower arrangements. Again, similar parts are named with similar reference numerals. This embodiment is characterized in that it is used to control the

Medium flow has no flaps, but blower with adjustable wings. Of course, the arrangement can also be made so that the medium throughput of a blind mounted in front of the fans or the like. is regulated.

Another way to regulate the medium throughput is given when the speed and possibly simultaneously the sash position of the fan is variable. Also can blower with

Direction of rotation reversal can be used, whereby the ventilation direction in the stacks is reversible. Furthermore, it is possible to assign each climate zone a separate exhaust device.

The individual elements of the drying channel such as blowers, heaters, sprayers and control valves and the transport device can be automatically controlled by an input side of the measuring devices --13,14- and optionally acted upon by a computer program electronic control device. In this case, the electronic control device preferably has comparison devices which are connected to the outputs of the individual stacks or stack groups associated measuring devices. In this way, optimal drying of the material to be dried can be achieved. The drying plant according to the invention can be used not only for drying wood, but also for drying other materials. Furthermore, the drying plant according to the invention can not only as

Drying channel but also be run as a drying chamber,