FI100033B - combination Boiler - Google Patents

Description

100033 - 1 -

COMBI BOILER

The invention relates to a heating boiler suitable for the incineration of municipal waste, which meets the structural requirements of Government Decision No. 626 / 1.8.1994 5.

According to these design requirements, the flue gas from combustion must be delayed for at least 2 seconds at a temperature of at least 850 ° C after the last air injection and the oxygen content of the gas must be at least 10%. To achieve this, a special hot chamber is placed between the boiler furnace and the convection part, in which a turbulent gas flow ensures a uniform oxygen content and thus the so-called elimination of super toxins (PAH, PCDD, PCDF, PCP and HCN). The structure of the hot chamber is protected by patent 84750 and is shown in Figure 1 by reference 15 7. The geometric shape of the hot chamber, which forces the gas flow alternately down and up, is also particularly suitable for dynamic hot flue gas cleaning due to the high (1200 K) solids gas flow. due to temperature, on average 200% less than in normal cleaning, with an average flue gas heat-20 of 400 K. In other words: according to Gay-Lussac's law, a solid dust particle flying in a cold flue gas stream receives three times (1200/400 = 3) thrusts to maintain molecular stroke in a hot gas stream, whereby the effect of gravity is correspondingly intensified and the dust particles fall to the bottom of the hot-25 chamber. Hot cleaning is important because the above regulation (Vnp 626) allows a maximum particulate emission of flue gas of 10 mg / m 2 (n), i.e. less than 5 mg / MJ, which is 40 times lower than the particulate emission allowed for conventional heating plant operation of 200 mg / MJ. Another significant advantage of hot cleaning is that the hot surfaces of the convection section 30 remain clean and the boiler does not need to be equipped with a soot cleaning mechanism. The problem, on the other hand, is the turbulence required of the gas flow, which largely negates the dust separation capability obtained from the above-mentioned high temperature.

The object of the invention is to eliminate this drawback and is achieved by placing a labyrinth chamber according to patent 92520, shown by reference numeral 12 in Fig. 2, between the firebox and the hot chamber. The refractory walls and thermal insulation of the labyrinth chamber 100033-2 are indicated by reference numerals 10, 11 and 13. In maze structures, the velocity of the burning gas flow is 30. 40 ..60 m / s, which achieves strong turbulence and a high combustion temperature. However, the residence time of the flue gas is only 0.1 ... 0.2 s, so the socket coil chamber alone does not meet the residence requirement of the above-mentioned decision (vnp 626), but when added to the residence time of the hot chamber, it confirms the overall result. Most importantly, however, the velocity of the homo-45 generated gas stream in the maze by vortex combustion is slowed by substantially increasing the flow cross section of the boundary point (14), which makes the flow in the hot chamber 1 laminar. In this case, a mandatory 2-second delay can also be used for hot flue gas cleaning under ideal conditions.

50

The solution is illustrated in Figure 4, which shows that the flow cross-section in the hot chamber (5) is clearly larger than elsewhere in the boiler. When this is combined with a homogeneous 1 amine flue gas flow and a reduction in transport capacity due to the high (1200 K) temperature of the gas, the hot chamber can be considered as a high flue gas purifier. The dust separated from the gas stream descends through a grate at the bottom of the hot chamber into a collector pocket, from where it is dropped by means of a cola into the ash conveyor (13).

The invention is characterized by what is set forth in the characterizing part of the main claim. The invention will now be described in detail by means of a working example with reference to Figures 3 and 4 of the drawing. Figure 3 shows a pressure vessel body of a combination boiler consisting of a fuel magazine (1), a furnace (2), a convection section (3) and space 65 for a maze chamber (4) and a hot chamber (5). The figure also shows the grate (6), the air inlets for the gasification air (7) and the combustion air (8) and the boiler foundation (9). Figure (4) shows a working combination boiler into which the municipal waste to be incinerated enters through the magazine (1). In the glowing fire layer (11) on the grate (6), the fuel is charred and converted to air gas (CO + H2) by means of gasification air (7), which mixes with combustion air (8) in the furnace (2) and burns back in the maze chamber (4) the flue gas lingers for at least 2 seconds, at which point most of its dust particles separate. It should be noted that in the VTT / KEMIANTEK-100033 - 3 - NUKAN unit in the autumn of 1994, the flue gas particle concentration after the cyclone separator alone was only 10, 27, 13 and 34 mg / m3 (n) in the mixture combustion of Estonian crushed stone and wood chips 75-U + i). The hot chamber is then followed by rapid cooling in the convection section (3). The maze hose o and the hot chamber are well insulated on all sides and above them there is a gas-tight lid (10). The ash generated during the incineration collapses between the grate irons 80, but the unburned stone, glass and metal goods among the waste pass along its surface through the slag removal opening (12) to the conveyor (13) due to the grate movement.

Claims (1)

'4' 100033 CLAIMS A combination stack with a maze chamber (4) 5 to improve the degree of combustion and a hot chamber (5) in which the flue gas is delayed at a temperature above 850 ° C for at least 2 seconds, characterized in that the maze chamber and the hot chamber at the boundary point (14) the flow cross-section increases, resulting in a slowing of the rapid and turbulent gas flow developed in the maze and becoming 1-laminar, whereby most of the flue gas solids settle to the bottom of the hot chamber, where they can be easily removed and flue gas cooling clean. i i. hi m n i 100033 - 5 - Kombinationspanna soin utöver en conventional convention (2) omfattar en labyiintkammare (4) som förbättrar förbränningens fullständighetsgrad samt en momammare (5) i vilken rökgasen bringas att dröja ätminstone 2 sek. at a temperature of up to 850 0 C, the temperature of the genomic chamber (14) is measured in a labyrinth chamber and in an instantaneous manner, the reserve is used in the labyrinth chamber and the turbulent gas column in the field, the particulate matter in the headform is reduced to a maximum of a few times, and in the case of a cone (3) someday in the headform.