DE2215065A1 - PROCEDURE FOR FILTERING DUST GASES IN POCKET OR HOSE FILTERS - Google Patents

Description

PATENT LAWYERS

DR. HUGO WILCKEN DIPL.-ING. THOMAS WILCKEN

D - 24 LÜBECK. WIDE STREET 52-54

Dr. Whale".

Applicant: Heinrich Lühr YDI Staubtechnik, 4960 Stadthagen, Enzer Straße 26

Process for filtering dust gases, pocket or

Bag filters

The invention relates to a method for filtering of dust particles containing dust or smoke gases in pocket or S _c hlauchfiltern, where the filtered out in the filter dust, depending on the properties of the fine dust to the agglomeration of the filter in amounts as of the order of 2 to lOOfachen Staubanceils the amount of fine dust arriving per unit of time and contained in the gas to be filtered is removed and fed back to the J: dust gas to be cleaned in front of or in the filter and an accumulating amount of dust is removed from the filter that corresponds to the amount of dust contained in the dust gas to be cleaned per unit of time.

In special cases, flue or dust gases contain gaseous or vaporous sulfur or chlorine compounds, which are harmful to the environment and must therefore be removed from the gases in such a way that they no longer enter with the clean gases Free nri-ums.

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It is already known F-. tuic ligases, the sulfur or chlorine compounds, s.B. . '. contain sulfur dioxide to supply chemical substances (additives) that chemically do the sulfur dioxide bind that the resulting connections are not or only partially are water-soluble and are therefore deposited in suitable places without impairing the groundwater to an inadmissible extent. It has already been suggested for this purpose the flue gases from s.B. oil-heated power plants in the boiler combustion chamber in front of electrostatic precipitators or wet cleaning systems Add potassium compounds in powder form or sprayed as a suspension into the combustion gases.

In practice it has been shown (see magazine " ^f Jheni.i eir- ^ enieurtechnik" 1972, volumes 1 and 2, article Λ.Μ. Squnei) that, due to the aforementioned measures, only a very small percentage of sulfur - or chlorine compounds of the R _a uch- or Gtaubgases can be purified, which is substantially wchl is because since ··), the time for binding of sulfur and chlorine in the chemical additive is relatively short, or that if higher desulfurization can be achieved then the effort becomes uneconomical, and very large excess amounts of additive substances have to be added, which for the most part must be regarded as a loss. The low desulphurization effect of electrostatic precipitators or external cleaning systems with the addition of chemical additives is largely due to the fact that: The gas to be cleaned can pass through such systems without causing many small partial currents.

30984W061Ö

BAD OBSQiNAL

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The object of the invention is now to be in the to be cleaned Gases containing sulfur or chlorine compounds enough time for the sulfur or schefeld dioxide to react or to give the chlorine ions with the chemical additive to be added and add additives to the gases to be cleaned and to lead in such a way that no or only extremely small losses of additives occur which do not occur with the sulfur or chlorine the sulfur or chlorine compounds contained in the gases to be cleaned react.

This object is achieved according to the method of the invention solved that using the method mentioned in the circuit to constantly be fed back to the filter, in Filter agglomerating dust chemical substances (additives), advantageously in powder form or as a suspension, those with sulfur or chlorine contained in the dust gas to solidify, react to filterable substances.

This combination of procedural steps is particularly effective simple and economical way created the possibility the sulfur or chlorine in the gas to be cleaned sulfur or chlorine compounds contained up to any Degree or completely or almost completely to the additive to tie. It is namely by using a faschen- or Bag filter the incoming gas flow to be cleaned in many

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'INSPECTBD

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Tiny partial flows are subdivided, so that the probability of the sulfur or chlorine compounds contained in the gas to be cleaned coming together with the powdery additives is greatly increased. The additives can also be added to the gas flow as a suspension when the gas to be cleaned has higher temperatures, since the water in the suspension can then evaporate in the filter, while the additive remains as a powder. Above all, it is now possible to add additives to the gas to be cleaned in any excess without or ■ almost without losses or only as many additives as is normally required to bind the sulfur or chlorine in the gas to be cleaned arriving per unit of time, but nevertheless to achieve an arbitrarily large excess amount of additives for the chemical reaction, because the additives which do not lead to the reaction are also returned to the filter with the dust recirculation, so that any desired excess of additives is obtained that is capable to let the sulfur or chlorine compounds react in the gas to be purified completely or almost completely with the additive. If the time for reacting the S _c hwefel- and chlorine compounds, with the additive is not sufficient, it is naturally possible, the number of circuits for the To increase the recirculation of the dust accumulating in the filter as required.

The combined process steps, namely any desired The number of cycles for the dust recirculation for pocket or bag filters and the supply of additives is the result Possibility of using the additives used with only very little

ORIGINAL »Κ ** Κ ™

Losses for reaction with those in the flue gases or the like To force contained sulfur or chlorine compounds, whereby it is also possible to add the additives continuously or intermittently to the gas to be cleaned. -

For the reaction of the sulfur or chlorine in the sulfur or Chlorine compounds of the smoke or dust gas to be cleaned or the sulfur dioxide and / or chlorine ions contained in these gases The additives to be added in powder form or as a suspension to the gas to be cleaned come first of all Oxides or hydroxides of alkali metals, alkaline earth metals, aluminum "or other chemical substances for use with the "sulfur or chlorine of the .Sulfur or Chlorine compounds react to form solid matter that can be filtered. Calcium oxide, for example, can be used as a dry powder or as a suspension (burnt lime), calcium hydroxide, sodium hydroxide, potassium hydroxide, Dolomite (calcium magnesium carbonate), magnesium (semi-burnt Dolomite) as additives. Find use.

It is understandable that by using pocket or bag filter systems with dust recirculation in the circuit accordingly an older suggestion of "adding additives to -. a particularly simple method and a particularly simple one System leads to the sulfur or chlorine of the sulfur or chlorine compounds contained in the smoke or dust gas, completely, or react almost completely to form solid, filterable substances to leave without causing major losses of additives. ■., .- '

309841/0610

& BIQINAL INSPECTED

Claims (2)

DR. HUGO WILCKEN DIPL.-ING. THOMAS WILCKEN D - 24 LÜBECK. BREITE STRASSE 52-54 Applicant: Heinrich.Liihr 7DI Staubtechnik, 49bO Stadthagen, Enzer Strasse 26 patent claims 1. A method for filtering dust or flue gases containing dust particles in pocket or hose filters, in which the dust filtered out in the filter, depending on the properties of the fine dust to its agglomeration, the filter in amounts approximately in the order of magnitude of 2 to 100 times the amount of dust arriving per unit of time , is removed from the amount of fine dust contained in the gas to be filtered and continuously fed back to the dust gas to be cleaned in front of or in the filter and an accumulating amount of dust is removed from the filter that corresponds to the amount of dust contained in the dust gas to be cleaned per unit of time, characterized in that the in the circuit constantly be supplied to the filter again, resulting in the filter or agglomerating dust chemical substances, advantageously in the powder form or be supplied as a suspension, the solid au with dust contained in the gas is sulfur or chlorine, react to form filterable substances. 2. The method according to claim 1, characterized in that the Amount of dust accumulating or agglomerating in the filter ~ ² ~ 309841/0 β 10 2215865 ! chemical substances to be added to the content of the i Sulfur dioxide bsw. dör chlorine ions or the like adapted " will. . ■. :. 1. Terfahren according to claim 1 or 2, dad.urch gelcisiert that ■ as chemical Susatzstoffe Oxj'de or hydroxides of alkali metals, alkaline earth metals, aluminum or other chemical substances are used with the sulfur or chlorine of the sulfur contained in the dust gas - or chlorine compounds react to form solid, filterable substances. 09841 / OS10