DE2731339A1 - Toxic fume spread preventing system for waste incinerator - combines chlorine, fluorine and sulphur fumes in filter system - Google Patents

Abstract

The fume, dust and smell spreading prevention arrangement is used in waste material incinerator. The latter incinerates also timber, tree bark, annual plants and peat. Coal or brown coal may be added. Toxic fumes generated are chemically combined into harmless compounds. All waste including refuse is chopped to an average size of walnut. The material is fed into a furnace. The flue gases are cleaned in a filter in which gaseous toxic compounds for example those of chlorine, fluorine and sulphur are combined chemically.

Description

Procedures for preventing dust and @ eruchsb @ @stigungen

in waste incineration plants The invention relates to a method to prevent vo @ dust and odor nuisance in waste incineration plants, which also contain mixtures of cellulosic waste, such as wood, bark, annual plants, Peat etc., if necessary with the addition of coal or lignite, and domestic and Commercial waste is incinerated.

Dust and odor nuisance occur both with the battery discharge and preparation as well as after the incineration on the single siliceous incineration multiple waste is not practiced to this day. The reason is likely to be too different "grain size" of the materials.

Theoretically it would be possible to use a well-known waste incineration plant also to supply wood waste, the burnout of the very different material structure the fuel, however, is likely to encounter difficulties.

This will especially occur when the wood waste is on the Garbage can be dumped, with the sch @ real burning and moister garbage on the cold @ rust is below @ and then burns out badly in any case.

The reverse stratification, namely wood waste and possibly To cleave coal to an evenly burning bed on the grate and the Shoving garbage on top of it results in significant loading problems for the garbage additive.

Only one procedure has become known in England in which over a coal fire, which is carried out on a moving grate of normal design, the shredded garbage is blown in. Blowing in shredded, unseen Miill, however, results in a pleasant wear @@ de @ @inblasventilateren, Ro @ r lines and @@@ b @@ sd @ sen. the @@ @@ each @ @@@@@ is sighted, @. H. Glass, Stones and the like sorted out, so the effort for the mulla preparation is much too @och in general for such mixed firing systems.

If @er garbage is to be processed, if necessary only shredded, this inevitably causes dust and odor problems.

@ another problem @ all small and medium-sized waste incineration @@@ age @ is the smoke cleaning. Airborne dust is generally caused by electrostatic precipitators separated, but the gaseous pollutants must be washed out with a Na @ scrubber will. A complete water purification system must then be arranged behind the Na @ scrubber will. The entire exhaust gas cleaning system is sometimes too expensive the cost of the entire waste incinerator. This is especially true for smaller and medium-sized units too.

The invention avoids these disadvantages by incinerating waste with preferably a mixture of cellulosic waste, such as wood, bark, Annual plants, peat, etc., - if necessary with the addition of coal or lignite - and household and commercial waste, in which all waste, including garbage, is stored in one Average Kor @ size from @ alnut to matchbox crushed, @ls Bulk material mixture introduced into the furnace, for example a moving grate furnace is and a flue gas cleaning in a packed bed filter in which the gaseous Pollutant compounds, for example from chlorine, fluorine, sulfur etc., to the alkaline ones Fly dust is bound in particular from the wood-like waste.

According to the method according to the invention, all accruing or transported garbage and industrial waste u @@ ittelbar zerk @ e @ nert, da @ ei da @ or or da @ ach if necessary in a known way from Eisen or gr @@@@@@ @is @@@ @@@ @ ag @@ table get @ ennt and then in ges @@ lossene Bun @@@ with mechanical Discharge required, from which some air is constantly sucked out and used as a combustion air additive @@ the firing is given. In addition, air can be used for combustion in a known manner be sucked out of the unloading station and the entire preparation.

Likewise, the Sp @@ air from the @periodic cleaning of the layer filter cells in a fabric filter @ o @ which optionally with chlorine, fluorine or sulfur dioxide enriched alkaline airborne dust is largely separated and then also as combustion air additive put in the furnace.

The proportion of wood waste in the fuel mixture should be very low be or should it be a pure incineration of garbage, it will be Bulky bed filter or the bulk bed filter cells with one or more fluidized bed reactors combined, which consists of a filling of powdery to fine-grained components Have lime, ground ash or slag or the like.

The fluidized bed reactor (s) are preferably the bulk bed filter upstream and not from the flushing air during backwashing of the packed bed filter applied.

This new process offers very significant advantages: 1.) The bulk material mixture from uniformly pre-shredded waste of approximately the same grain size, e.g. B. from woody Waste and garbage, possibly with the addition of coal or lignite, results Good and even combustion with a low proportion of carbonization gas in every furnace.

2.) The u @@@@ tte @ bare crushing and bunkering of the resulting or approached garbage avoids any environmental pollution by smell, insects, Katten and the like, because practically no "mountains of rubbish" are left behind. Additionally a possible odor nuisance of the area due to the storage of the zer - @@ one Rubbish in Si @ os or bunkers @it mechanical discharge avoided because @ from A little air is constantly extracted from these bunkers or silos and used as an additive for combustion air is added to the furnace.

3.) Due to the high proportion of potash and other alkaline components in the bag ashes, especially from the wood-like waste, are in the bed filter gaseous pollutants bound to the fly ash and with this in the periodic Cleaning the loose-fill filter cells deposited in dry form while the rinsing air possibly still laden with the smallest amounts of very fine dust is again given into the furnace as combustion air. The known effort for electrostatic precipitators and Na @ scrubbers with subsequent water purification not applicable so completely.

4.) Should the proportion of wood waste be low or just u @ act a pure waste incineration, so too little alkaline fly ash could be produced, to bind the gaseous pollutants. In this case, you can simply @eise the layer filter or

the single rubble filter cells a fluidized bed reactor or a battery of several fluidized bed reactors can be assigned to the one powdery or fine-grained material is filled, which contains the gaseous pollutants absorbed. Lime is known for this, especially calcium hydroxide, but also ground Incineration ash or incineration slag from waste incineration itself is well known suitable to absorb the gaseous pollutants.

Of course, it is advantageous to use several fluidized bed reactors, so that these can also be cleaned periodically or that periodically their filling can be exchanged. Especially when the filling is almost dusty It is advisable to install fluidized bed reactors in front of the bulk bed filters, dust that may be entrained from the fluidized bed reactor in the bulk bed filter is deposited0 Of course, it is useful when backwashing the packed bed filter not to direct the purge air backwards through the fluidized bed reactor. This purge air is then expediently directly via a further filter system, for example a fabric filter passed to separate the fly ash and then as an additive for combustion air used.

Another essential advantage of the method according to the invention, in particular with the combined incineration of wood waste and garbage is the The fact that pure waste incineration plants are only available in metropolitan areas such as large cities with at least 500,000 inhabitants are to be operated economically. Through the mixed Incineration of wood waste, - if necessary with the addition of coal or lignite - and garbage can also be found in smaller catchment areas in the vicinity of one or more Industrial companies with a high amount of waste, such as bark, chips and the like, Waste incineration plants are built on an economic scale0

Claims (4)

Claims: 1.) Method for preventing dust and odor nuisance in the case of waste incineration, which also includes mixtures of cellulosic waste, such as wood, bark, annual plants, peat etc., - if necessary with an addition of coal or lignite - and household and commercial waste are burned1 as a result marked, da @ all waste including garbage to one average grain size from walnut to matchbox shredded than Bulk material is introduced into the furnace, for example a feed grate furnace and since @ the flue gases are cleaned in a packed bed filter, in which the gaseous pollutant compounds, z. B. of chlorine, fluorine, sulfur etc., be bound. @.) The method according to claim 1, characterized in that the entire Accruing or transported garbage is shredded immediately, if necessary after a known magnetic separation of the iron parts in closed bunkers with mechanical discharge is promoted, air is constantly sucked out of dents and <l is added to the furnace as an additive for combustion air. 3.) The method according to claim 1, characterized in that the Sp @ l air from the periodic cleaning of the packed bed filter cells in a fabric filter of the alkaline, optionally enriched with chlorine, fluorine or sulfur dioxide Flue dust is largely cleaned and then used as an additive for combustion air is added to the furnace. 4.) Process according to claims 1 and 3, characterized in that then with pure waste incineration or only a small amount of wood waste in the Firing of the bulk bed filter with one or more fluidized bed reactor (s) with a filling of powdery to fine-grained components of lime, ground Ash or slag or the like combined is0 5.) Method according to claim 4, characterized in that the / the, Ji rbelschiclitreaktor (ell) the bulk bed filter is / are upstream and not when the bulk bed filter is folded back is / are acted upon by the purge air.