[0001] The present invention concerns a drive-through chamber type timber drying kiln, where
the timber loads to be dried are conveyed on a roller track or equivalent through
a front door into the drying kiln, and from which drying kiln, subsequent to drying,
the timber loads are removed on the opposite side of the drying kiln through a back
door.
[0002] So-called drive-through chamber type drying kilns are known in prior art. Their structure
is such that drying kiln loads assembled of drying kiln packages are carried into
the drying chamber on a roller track in front of them, whence the loads are pushed
into the drying chamber. The dried loads are taken out through the opposite door of
the drying chamber. It is an advantage of these chamber-type drying kilns known in
the art that in them the load changing time is comparatively short. However, a disadvantage
is the expensive realization of such drying kilns, because they require two opposite
doors, and roller tracks on both sides of the drying chamber. The object of the present
invention is to provide a simple design by which the drawbacks mentioned can be substantially
reduced, and to provide a chamber-type drying kiln in which the advantageous characteristics
of the chamber-type drying kiln, mentioned above, are preserved.
[0003] For attaining these aims and those to be disclosed below, the invention is mainly
characterized in that in the drying kiln two or more drying chambers are connected
in series and that of these chambers connected in series each chamber operates independently
in the way that when the timber loads are transferred from a first. chamber to a next
chamber, in this latter chamber the drying is carried on substantially from that point
of the drying schedule which had been reached in the drying process in the first chamber.
[0004] In the following, the invention is described in detail reference being made to an
embodiment example of the invention presented in the figures of the drawing attached,
to the details of which the invention is not confined.
[0005]
Fig. 1 presents in elevational view a chamber-type drying kiln of the invention. Fig.
1 is at the same time the vertical section along the line I-I indicated in Fig. 3.
Fig. 2 shows the vertical cross section II-II in Fig. 3.
Fig. 3 shows the horizontal section III-III in Fig. 2.
[0006] As shown in the figures, the chamber-type drying kiln comprises four drying chambers
K
1, K
2, K
3 and K
4. The chambers K
1 and K
2 among themselves and the chambers K
3 and K
4 among themselves are connected in series. Thus, the chambers K
1 and K
2 in ombination and the chambers K
3 and K
4 in combination constitute two chamber groups, both of them having only one front
door 11 and one back door 13. Through the chamber groups K
1, K
2 and K
3, K
4 pass the roller tracks 10. The initial parts 10a of these roller tracks are located
outside the doors 11, and similarly the ultimate ends lOb of the roller tracks 10
are located outside the rear doors 13. The timber loads P
1 to be dried are brought to the initial ends 10a of the roller tracks, and the finished
dried loads P
4 are taken off the ultimate ends 10b of the roller tracks 10.
[0007] The chamber-type drying kiln comprising two drying kiln groups is composed of outer
walls 14 and partitions 16, of a roof 15, and of the front doors 11 and rear doors
13 mentioned. Between the first chambers K
1 and K
3 and the second chambers K
2 and K
4 are provided light-weight partitions 12, for instance made of flexible fabric-type
material, because these partitions 12 need not be thermally lagging. The partitions
12 are advantageously of such kind that it is possible to push the drying kiln loads
P
2 through them from the first chamber K
1, K
3 to the second chamber K
2, K
4.
[0008] Each drying chamber K
1-K
4 is provided with means by which circulation F
k of drying air through the timber loads P
a and P
3 composed of packages provided with spacers is achieved. Said means comprise one or
more blowers 20 and a heating radiator 21 placed in a duct 22. On the intake side
of the blowers 20 in the duct 22 is introduced through ventilation ducts 26 an inlet
air flow F
in from outdoors, and similarly, on the pressure side of the blowers 20, an outlet air
flow F
out is taken off through ventilation ducts 25. In connection with the ventilation ducts
25 and 26 are provided control dampers 23 and 24, by the aid of which, combined with
regulation of the radiators 21, the drying capacity of the circulating air F
k is influencable. Said means are separated from the load space by a partition 17,
which is open on both sides (apertures 18 and 19). Through one aperture 19 the circulating
air can pass to one side of the load, and through the other aperture 18 it is enabled
to return to the blowers, having in the meantime passed through the loads. The direction
in which the air circulates is reversed at regular intervals, usually automatically.
[0009] The drive-through chamber type drying kiln described in the foregoing operates as
follows. The first chambers K
1 and K
3 and the second chambers K
a and K
4 of the chamber groups operate independently. When loads P
2 are transferred from the first chambers K
1, K
3 into the second chambers K
2, K
4, drying is carried on subsequent to this transfer as if no transfer had taken place,
in other words, after the transfer, one begins to follow the drying schedule in the
second chambers Kz,K
4 starting at that point in the drying process which had been reached in the drying
in the first chambers K
1, K
3. It is advantageous, to this end, if the circulating air flows F
k in the first chambers K
1, K
3 and in the second chambers K
2, K
4 have opposite direction.
[0010] As has been set forth, each group of chambers contains two drying chambers K
1, K
2; K
3, K
4, In certain applications there may be even more such chambers in series, for instance
three or four.
[0011] It is thus understood that in accordance with the invention a drive-through chamber
type drying kiln has been obtained in which for each chamber group K
1, K
2 and K
3, K
4 there are still only two doors 11 and 13 and only one roller track 10 or equivalent
track system passing through the chambers.
[0012] In the following are stated the claims, various details of the invention being allowed
to vary within the scope of the inventive idea thereby defined and to deviate from
those presented in the foregoing.
1. A drive-through chamber type timber drying kiln, where the timber loads (P) to
be dried are conveyed on a roller track (10) or equivalent through a front door (11)
into the drying chamber, and from which drying kiln the timber loads (P) subsequent
to drying are removed on the opposite side of the drying kiln through a rear door
(13), characterized in that in the drying kiln two or more drying chambers (K1, K2; K3, K4) are connected in series and that among these series-connected chambers (K1, K2; K3, K4) each chamber operates independently in the way that when the timber loads are being
transferred from the first chamber (K1, K3) to the next chamber (K2, K4), in this chamber (K2,K4) the drying process is carried on substantially from that point of the drying schedule
which had been reached in the drying process in the first chamber (K1, K3).
2. Chamber drying kiln according to claim 1, characterized in that drying chambers
(K1,K3) and (K2,K4) have been provided at least two in series and that chamber groups thus produced
are disposed one or several in parallel with each other.
3. Chamber drying kiln according to claim 1 or 2, having on one side of the drying
chamber an air circulation duct (22) with blower means (20), a heating radiator (21)
and intake air intake and exhaust means (23,24,25,26), characterized in that in the
chambers (K1, K3; K2, K4) connected in series the circulating air flows (Fk) have been arranged to be opposite in direction.
4. Chamber drying kiln according to any one of claims 1 to 3, characterized in that
between the drying kiln chamber groups (K1, K3) and (K=,K4) there is a partition (12) with light-weight structure, preferably a partition made
of flexible fabric-like material, which when raised permits the running through of
its drying kiln charges from the first chambers (K1, K3) to the second chambers (K3, K4).