DD216443A5 - METHOD FOR WELDING SLEEPING AND / OR ORGANIC MATERIALS - Google Patents

Abstract

The invention aims to increase the dewatering efficiency in terms of throughput and residual moisture of the dewatered sludge by mechanical presses (e.g., filter belt presses) or centrifuges to the extent that further dehydration stages are superfluous and e.g. The dewatered sludge can be burned in a fluidized bed furnace without Oelzusatz- or Stuetzfeuerung. According to the invention, the sludge and / or organic substances are added to a temperature of 100 to 200 degrees C after application of the mechanical pressing or centrifugal forces by direct application of saturated steam in the pressure range from 1 to 15 bar heat. In this case, additional compressive forces are added to the pressing or centrifugal forces when using superatmospheric pressure, wherein the thermal load by applying saturated steam substantially improves the dehydrating behavior. Preferably, working at saturated steam pressure of 10 bar at 180 degrees C, wherein the saturated steam is to be used in ener amount, with which the material to be dewatered not more than 100 degrees C, preferably not above 80 degrees C, is heated.

Description

Berlin, 17.5 · 1984

63 657/25/20

Process for dewatering sludges and / or organic matter

To wend ungsgebi et _ti of. ,, Erf indun g

The invention relates to a method for dewatering sludges and / or organic substances "in particular sewage sludge" under mechanical stress of the material to be dewatered, in particular using compressive forces and / or acceleration forces »

It is already known! prior to dewatering the sludges and / or organic substances, for example in a sieve belt, or centrifuging the sludge, which is generally depressurised with flocculants and with steam. The material pretreated in this way is used in the Subsequently pressed or centrifuged and can subsequently be fed to a further dewatering or drying stage *

The water is bound in sludge in various forms to the solid, and the water content depends largely on the type and size of the solids. "In principle, it can be said that the smaller the size of its solid particles, the greater the water content of a sludge the more organic material is included,

According to the type and binding of the water to the solid under «

·: R, r i. #> y

( If sche «Β® is separated from a municipal sewage treatment plant with 95% WG in a fouled sludge«

Between «or cavity water. about 70%

Adhesion »© Adhesion Waser ¹ » Capillary «·

water * U ₁₉ a * Interracial capillary » ¹ !

Pore angle «· '<and coarse capillary water. about 20 %

Adsorptlons ^ ater »Indoor Water ^ a ₉ Cellular Hydrate * and Indoor»

ea. 10%

However, the fluctuation range of bound specific amounts of water is very high and has an effect on the adaptability and performance of the individual separation processes.

The Sindungskräft © between the solid and the water took of intermediate * 'od @ r Hohlraumwaseer via the adhesion "and capillary water to adsorption" bz, w, indoor water strongly zuffl Ira same spirit takes the space required for the dehydration energy required to "The drainage must the described binding forces are broken «

Since © between · or cavity water | Thus, the free water swiaefeesi of the solids without direct binding to the solids can be largely separated by thickening, and thus by the effect of the SehM?

The imprisonment results in adhesion water and the capillary water is evacuated by negative pressure both from the cohesive forces of the river.

Being bound by the adhesion forces of the solid and can be largely separated by mechanical action, such as centrifuging, pressing or application of vacuum *

The surface-bound water (adsorption water) is very strongly bound by the surface or surface forces of the solid. "The adsorptive forces are the Coulomb forces, the van der Waal forces (electrostatic forces) and the forces of dispersion (the forces of attraction between the atoms and molecules occur) to the effect «

The adsorption water is highly compressed «In the literature

pressures of 10 000 to 25 000 kp / cm are mentioned. "At these high pressures, the bound water behaves like a solid (" ice ")." The adsorption water sheath has a low thickness and is only 1 to 10 molecules with a layer thickness of O ₄ I to 0.15, um. The surface forces result from the fact that the binding forces of the surface molecules of a pesticide are not saturated to the outside and to compensate gas, "liquid molecules and cations are deposited." In the literature is welter stated that the surface forces are not completely saturated by the Adsorptionswasserschicht and therefore the remaining residual field binds further water dipoles and ions. This water, which is still under superatmospheric pressure, is slightly compressed to uncompressed, but still mobile. It is called solV on ion water, or even lyosorbated water.

A © weiter® way of bonding is given by the positive ions (cations) present on the solid ¹ !, which of their © water © dipper © binders _e Si® becomes al® hydration

Ent @ preoh © nd of the described different strong water binding can in the previously known Entwässerung "of sewage sludge © ^ wi® z" B "pressing or centrifugal

It can be up to 60 % to 75 % Snd £ ® @ © i? Meanwhile , the sludge is in the balance. © b © rei @ h from @ 0 to 65 % krüia © ligfest- « ^: im.Wae« »8 © rg @ h @ it © b @ r @ me by 70 to 75 % puncture resistant to mushy

Oi © procedure for the dewatering of sewage sludge, for the sake of economy:

using flocculants for the purpose of increasing the size of the solid particles

2 ". Erstwi®® © rn. (Pressing ^ Sucking ^ · Centrifuging) by generating drifting differences «'occasionally preconditio- nating the s Schlasifie® by heating with a heat exchanger«

3 * Drying feeder th @ nsii® © h energy. '

The aim of the invention is the provision of a method for dewatering sludges and / @ d®r organic matter _>

with which the dewatering effect of mechanical presses or centrifuges can be increased.

Exposition, dea esen W s, of the invention;

The invention is based on the object «; to improve the dewatering performance of the dewatered sludge by mechanical presses (eg ₀ filter belt presses) or centrifuges to the extent that further dewatering or drying steps are superfluous, and _{# 4} the dewatered sludge can be incinerated in a fluidised bed furnace without additional oil or »auxiliary firing *

According to the invention, the object is achieved »that the pre-dewatered by thickening and upstream dewatering sludge simultaneously mechanical stress and thermal heating by direct pre-dewatered sludge with saturated steam in the pressure range of 1 to 15 bar and a temperature of 100 ⁰ C to 200 ⁰ Cy preferably 10 bar at 180 ⁰ C, is exposed.

By applying a superatmospheric saturated steam pressure at the same time, the application of pressing or centrifugal forces can change the water binding in chemical and physical terms * so that the dewatering results of conventional filter belt presses ¹ * filter presses or centrifuges can be significantly improved by these measures

Bai d © r use of saturated steam occurs "as the attempts £ © tg®n" at about "200 ⁰ C © ine thermisch® decomposition of orga *" Nian substance * particular biogenic, substance is a "the © in © @ rs®it d®s application d © @ Feststoff® drops and on the other hand the rotary pressing © d © r centrifugation is separated © water with decomposed organic substance

effect is © © © © © © on the enormous © reduction of dyno «

         '6 2

Mix viscosity d® @ water of 102 * 2 »10 kp _e s / m

(20 ° C) to 14 '!' · ÄO ⁶ kp ^ s / m ² (200 ⁰ C) ^ reckel | andr © ra © it © isilrd the p © 2 _e Dieht © ^ from 0 | 999 (20 ⁰ C) to '0 * 865 (200 ⁰ C) lowered © B @ i the stepwise dureh »

first of all, by means of the above-mentioned effects, faster release of the adhesive and capillary water © in «,

8 @ i d @ rw @ 'tt®r®n Er ^ vartaung'-the mutual energy of the adsorptively bound Was @ © rsiol © molecule is increased in such a way that © separation is possible «

B @ i of Durchwä rpursg d @ ® solid is ";, or particularly the" ganischen solids "'komiBt it to a fabric @ r Ver borrowed" change to @ © @ r in further release of Hydrate "" and Innerskapillarwa®8 ®r led Di © heating of organic solids must not asu hydrolysis bzw® decomposition of organisch® "substance lead ₃ since this intention drainage d @ s S © hla (ara © s no longer would möglieh" Sta "sonder® easier W @ is @ can be used to make the over

«· 7 tm

Atmospheric pressure saturated steam can be used in an amount »with which the material to be dehydrated does not exceed 100 ° C | preferably not above 80 ⁰ C, is heated; whereby the desired change in the interfacial tension in the adhesion layer and the increase in temperature can be achieved with the same working medium. "

In particular, when using belt presses, a pre-dewatering is usually carried out using a low pressing pressure and subsequently a pressing with gradually increasing dirt "It has been shown that the most significant improvement in drainage ** performance * occurs when in use Such pressing is the introduction of saturated steam in the stage with the highest pressing pressure is made * In this way it is sufficient; only a part of the conventional dewatering machines can be covered with a housing in which the desired saturated steam pressure can be built up. The material to be dewatered is introduced via pressure locks in this case, the discharge into an optionally downstream pressure drainage being effected directly with the water When steam is used to increase the pressure during heating, a proportion of condensing heat is necessarily produced in addition to the pressed substance: and because this condensing water is richer in organic substances than the water pressed out without steam pressure and without temperature increase If it is advantageous if the water condensing when using steam to increase pressure and heating in the press or centrifuge

 - 8th -

is collected and subjected to pressure oxidation prior to discharge. "

The invention will be explained in more detail below with reference to two exemplary embodiments. In the accompanying drawings, FIGS. 1 and 2 show technological diagrams of the invention

d © r representation in Fig® 1 c3 © r fresh ausgebrachte from the biological Abwaeserrelnigungenahlage top "" schußschiafiHR or ausgefault © sewage sludge in Before "wall of flocculants ?! thickened and possibly iner after a Nachflockung © filter belt press common type supplied "After this preparation, '^ the very economic WEIS® $ @ n water content to 60 to 75% ver ~ Ringert" is the front @ nt ^ äesert @ mud in an under saturated vapor pressure operating filter belt press introduced and in the case of a schMr dewaterable sludge composition on «» © κ * 180 to 200 ⁰ C heated «

The water squeezed out under these conditions is continuously discharged. * The dewatered sludge is also discharged continuously and allowed to evaporate for the purpose of utilizing the tangible WaYiae present in the solid. This can be done on an Elrmi belt or a @ t »aeration unit (fluidized-bed dryer υ» a «)« Oe after further use of the dewatered sludge © ® and the residual water content thus required, a further Abtroekmmg effected by "that

The heat is extracted from the waste water of the pressurized Siebbandpreeee by heat exchangers and thus heated drying air and this is used for post-drying. "In the present example, the 30 to 35 % TS dried sludge in a fluidized bed incinerator without support firing eliminated." From the waste heat of the combustion gases the required saturated steam is generated for the pressurized filter belt press · The remaining waste heat can be used for heating purposes or else for a further drying of a part of the Schlanvmes for fertilising purposes or a briquette production «

The obtained during difficult drainable sludge hot wastewater »the * steam temperature is obtained when using the maximum permissible satellite" of about 200 ⁰ C and increased organic load has ^ is appropriately before being discharged into the biological waste water Reinigungsen "· location of Druckoxydation subjected * \ ,

In a further embodiment of the method according to the invention as shown in FIG. 2, a pressurized centrifuge is provided instead of the filter belt press operating under pressure. In the case of sludges having a particularly difficult drainage character, dewatering in the centrifugal field can produce better results. Otherwise, the process conditions are the same.

In both examples, the pre-separation of the easily separable water for reasons of minimizing the energy *

"IU it

Irs d @ r working under pressure © «only cä © r absolutely necessary®

Inside, the centrifuge *, in particular in 8'reiss' the same iet ein® Au®tr @ g © dffnusig for

Centrifuge under pressure

H @ iB ^ a @@ © r may © irefaeher W © © is direct

be and

Claims (4)

- 11 - R eporting application 1 «Process for dewatering sludge and / or organic matter '! In particular sewage sludge ^ under mechanical stress of the material to be dewatered, in particular under application of compressive forces and / or acceleration forces ^ characterized in that the thickened by thickening and upstream dewatering sludge simultaneously a mechanical stress and thermal heating by directly applying dee pre-dewatered sludge with saturated steam Pressure range from 1 to 15 bar and a temperature of 100 ° C to 200 ⁰ Cf preferably 10 bar at 180 ° C | is suspended « 2 »Method according to item 1, characterized by; that for the production of the superatmospheric pressure saturated steam is used in an amount with which the material to be dehydrated does not exceed 100 ⁰ O ^; _{9 is} preferably not heated above 80 ^° C. * » 3 «Procedure according to item 1 or 2 _# characterized by / that when using multistage presses ?! in particular Siebbandpresseri the saturated steam is added to the stage with the highest pressing pressure · 4. Method according to one of the items 1 to 3i, characterized in that the Waseer condensing with the use of steam for increasing the pressure and heating in the press or * centrifuge is subjected to pressure oxidation before it is discharged « For this 2 pages drawings