FI60435B - TORKANORDNING FOER EN PANNAS BRAENSLE - Google Patents

Description

Ϊ55μΠ Γβΐ ANNOUNCEMENT /; n47C

[BJ (11) UTLÄGGNINGSSKRIFT OU4 0 0 • C Patent granted 11 01 1932 1 Patent «eddelat v * (51) Kv.ik? /» Nt.a.3 F 23 K 1 / 04- FINLAND - FINLAND (21) Pttunttlhuktmu * - Pattntansekning 772660 (22) Hakamlaptlvi - AnsAknlngidig 07 · 09 · 77 (23) Alkuptlvt— Giltlghetadtg 07 · 09 · 77 (41) Tullut Julklsakai - Siirit offantllg 08.03-79

Patent ·) a Registry Board ...., ~. __. , _. (44) Date of issue and date of issue. -

Pttant · och registratyrelsen AnaMcan utlagd och utl.tkrlften publkerad 30.09.8l (32) (33) (31) Privilege requested — Begird prloritet (71) Oy Julius Tallberg Ab, Aleksanterinkatu 21, 00100 Helsinki 10, Finland -Finland (Fl) ( 72) Olavi Leppälä, Järvenpää, Finland-Finland (FI) (7H) The present invention relates to a drying device for boiler granular fuel such as sawdust, peat or the like with a flue gas-heated dryer. a space through which the fuel for conveying the screw is conveyed by means of conveyors to the furnace and in which the moisture of the fuel is transferred with the flowing gases flowing upstream to the outside air, whereby the fuel dries.

The disadvantage of such an imaging device is that its drying power is not sufficient when the fuel to be dried is very moist. This is because the heated space is some kind of tank that is heated by flue gases from the outside and the moist fuel in the tank dries only at points that are closed and close to the heated surface of the tank. If the Fuel is led in the pipes by means of screw conveyors, the moisture does not escape with the flue gases, but it travels in the opposite direction to the direction of the fuel flow, which makes it very difficult for it to escape.

The object of the present invention is to obviate the above-mentioned drawbacks and to provide a more efficient fuel drying device.

The drying device according to the invention is characterized in that the heated space is a vertically elongated, uniform flat chamber with a plurality of horizontal screw conveyors superimposed, below which there are gutters in which the fuel flows back and forth from one screw conveyor to another, and that the flue gases pass shaped upwards in the same space via screw conveyors into the flue gas outlet. In this way, heat is obtained throughout the space because the flue gases are led in from the lower part of the space and out from the upper part. Due to their heat, the flue gases travel upwards and circulate around the screw conveyors, heating the fuel in the screw conveyors so that the moisture in the fuel evaporates and moves with the flue gas and flue gases to the outside air. Moisture in the fuel is easily transferred to the flue gases because the gutters are open from above over their entire length. As the fuel moves from one chute to another and back and forth, the fuel to be dried is given a long enough distance in the heated space to dry effectively.

A preferred embodiment of the invention is characterized in that the troughs are tightly connected to the walls of the chamber. In this way, a long controlled travel distance for the flue gases is obtained, whereby the thermal energy can be used as well as possible.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which

Fig. 1 shows a drying device according to an embodiment of the invention attached to a boiler and cut.

Fig. 2 shows a section taken along the line II-II in Fig. 1.

Fig. 3 shows a imaging device according to another embodiment, a section taken along line 111-X11 in Fig. 4.

Fig. 4 shows a section taken along the line IV-IV in Fig. 3.

Figure 1 shows a fuel drying device 1 attached to a boiler 2. The dryer 1 has screw conveyors 3 superimposed in the same vertical plane so that the fuel coming from the feed opening 4 falls directly into the uppermost screw conveyor 3, which transports fuel to the end of the chute 5 in the conveyor, from where it further falls to the next conveyor 3 and further down. the lowest screw conveyor conveys the fuel to the outlet 6. Below the outlet 6 there is a screw conveyor 7 which feeds the fuel into the furnace 0. The flow of flue gases from the furnace 0 to the flue gas outlet 9 is shown by 3 and 4 show another embodiment of the drying device, in which the flow of flue gases 10 and the flow of fuel 11 differ somewhat from the embodiment of the drying device shown in Figures 1 and 2. In principle, the operation in both applications is exactly the same. The flue gas from the boiler still has so much thermal energy (temperature approx. 250 ° C) that, when properly recovered, this energy dries very moist fuel. For this reason, the transport of fuel in the heated space is arranged by a screw conveyor 3 so that the fuel travels long enough and continuously mixed with screws so that most of the moisture in the fuel evaporates and is transferred with the flue gases to the outside air.

In the embodiment shown in Figures 3 and 4, the screw conveyors 3 are connected to each other by a chain drive 12, whereby the flow of fuel in all screw conveyors 3 is equally fast and smooth.

It will be apparent to those skilled in the art that various embodiments of the invention may vary within the scope of the claims set forth below. Thus, the drying device can be arranged to guide the flue gases in the desired way so that the heat of the flue gases is evenly distributed around each screw conveyor 3. Ribs can also be arranged outside the chutes 5 of the screw conveyors 3 so that the heat of the flue gas is better transferred to the chute and thus also to the fuel to be dried as efficiently as possible.