EP1303663B1 - Circulation method for the environmentally-friendly cleaning of contaminated textiles, namely industrial cleaning rags that are contaminated with solvent residues - Google Patents

Abstract

The invention relates to a circulation method and to a system for the environmentally-friendly cleaning of contaminated textiles, especially industrial cleaning rags that are contaminated with solvent residues. The articles to be cleaned (1) are supplied in a manner known per se to an industrial washing machine (2) and after washing to a drier (3). According to the invention, the collected air currents (5) extracted from the industrial washing machine (2) and/or the drier (3) or the ambience are transported to an oxidation chamber (6) and oxidized. The energy of said chamber is supplied to a steam generator (7) that communicates with a device for pre-heating the washing water and with a waste water purification installation (9) so that the waste water (10) can be evaporated and thus purified and the industrial water (11) purified in this manner can be returned to the industrial washing machine (2) with only little external energy supply.

Description

The invention relates to a circulation process for the environmentally friendly cleaning of textiles containing harmful substances, in particular industrial cleaning cloths with solvent residues, wherein the cleaning material of an industrial washing machine and after the washing process is fed to a dryer, according to the preamble of patent claim 1, and an arrangement for carrying out such process.

Industrial washing and cleaning systems have been state of the art for decades. In the course of an ecological process management, it is in such systems, both energy while heating the actual washing facilities and dryers to save as well as to reduce the hot water demand.

Especially in industrial textiles, e.g. Industrial cloths, there is the problem that such textiles are usually contaminated with solvents and thus. Such solvents are released during the washing and drying process and so far reach the environment as pollutants. A circuit arrangement in terms of supplied fresh water and treated wastewater by condensation has been proposed, however, the energy costs are considerable, so that can not be assumed in such a process management respectively suitably designed systems from a reasonable business procedure. A method for cleaning industrial Patztüchern is known from US 5,222,267 A, a device for purifying the exhaust air from Textilverechlungsmaschinen is known from DE 38 06 193 A1.

From the foregoing, it is therefore an object of the invention to provide a further developed under environmental aspects cycle method and an associated arrangement for cleaning texturized textiles, especially industrial cleaning cloths with solvent residues, not only the fresh water supply should be minimized, but at the same time to ensure an energetically optimal operation of the entire facility.

The object of the invention is achieved by a method according to the features of claim 1 and an arrangement for carrying out the method with the features of claim (6), wherein the dependent claims comprise at least expedient refinements and developments.

Accordingly, the basic idea of the invention is to capture the liberated during the washing and drying process solvent-containing and thus energy side interesting vapors and gases to achieve not only a conversion of pollutants in a thermal oxidation chamber, but at the same time the energy balance of the chamber or chamber operation to improve.
For the purposes of this basic idea, the exhaust air from the washing machine and / or dryer is collected and mixed with fresh air via a collecting device and optionally preheated or cooled to the thermal oxidation chamber. Furthermore, it is possible to supply liquid solvent residues through a nozzle arrangement of the chamber.

It has surprisingly been found that by such additional energy supply due to the solvent residues in gaseous and / or liquid form, a significant saving of gas or other fuel materials is the result.

The energy generated in the chamber in the exhaust air purification process is then further supplied according to the invention a steam generator, the superheated steam is passed to a dirty water purification and evaporation plant.

The dirty water cleaning system is preferably designed in multiple stages and includes facilities for separating or separating non-condensable residues.

It is therefore possible not only to create a wash-wastewater cycle through an evaporation or condensation plant, but to optimize the energy supply of the evaporation system for the wastewater by using the energy of the solvent-containing residues that are bound in the soiled textiles.

As already indicated, it is therefore first of all necessary to pass the collected exhaust air streams from the industrial washing machine and / or the dryer into a chamber in order to oxidize them there or to release thermal energy.

The thermal energy from the exhaust air is then passed to a steam generator, which communicates with a means for preheating the wash water and a dirty water evaporation system, so that the desired minimum external energy supply both during evaporation and thus cleaning the dirty water as well as during heating of the thus cleaned, the industrial washing machine can be supplied again supplied hot water.

From the exhaust air streams condensed, highly solvent-containing residues or such residues collected in the dryer can be abandoned via a nozzle assembly in the chamber, so that a further improvement in the efficiency is given throughout the circulation process. The same applies to distilled from the wash water flammable substances.

The solid or other residues collected in the wastewater treatment plant can be recycled separately. In the case where such residues are flammable, there is the additional possibility of a corresponding task relative to the chamber.

The exhaust air streams are mixed via a corresponding control device with a fresh air stream and optionally fed via a preheater of the chamber, wherein the Preheating device is located in the exhaust stream of the chamber, ie in the clean gas path.

The dirty water purification system contains filter devices, at least one pre-evaporator, a centrifugal separator and a downstream stage with forced circulation - evaporator, so that the evaporation process is much more economically based on the state of the art and with minimal water content in the waste material can be designed.

In the arrangement for carrying out the method is initially assumed by a washing machine and / or dryer exhaust manifold, which passes through a corresponding ventilation device on a Abluftvorwärmer and is then in communication with a preferably gas-heated oxidation chamber. A mixing device is used for the controlled supply of fresh air to the chamber or for adjusting the ratio between fresh air and washing machine or dryer exhaust air.

In a further development of the arrangement, the highly loaded exhaust air of the washing line is thermally treated via a secure pipe in the oxidation chamber. The lighter-burdened extracted room air and the dryer exhaust air is also supplied to the oxidation chamber, however, this partial flow is regulated in order to prevent overheating of the chamber effectively.

Directly downstream of the chamber is a steam generator, which cools the gases and provides corresponding hot steam. The exhaust air preheater is used for further cooling of the clean gases with simultaneous heating of the exhaust air. If, in the absence of heat absorption by the steam generator, higher temperatures occur in the downstream exhaust air preheater and there is a risk of pre-ignition on the exhaust air side, the exhaust air preheater can be bypassed on the clean gas side.

The chamber itself has an additional nozzle arrangement for atomizing solvent-containing liquid residues, so that the energy contained in these residues is usable in the combustion process.

With the presented invention, it is thus possible during the washing and cleaning process of industrial textiles to catch the exhaust air from the washing machine and the surrounding area of the washing machine and to feed it via a pipe system to a thermal oxidation chamber. This eliminates a burden on the atmosphere. In the same sense, the exhaust air of the dryer can be collected and fed to the chamber.
The exhaust air laden with significant flammable substances releases energy during combustion, which is used to heat the steam generator. The energy released in turn serves to heat the wash water and to energetically supply the evaporation system for the dirty water. Through a dirty water cleaning system with downstream forced circulation evaporator, the entire wash water can be used again. There is no pollution of public wastewater treatment plants with contaminated materials.

The invention will be explained below with reference to figures.

Fig. 1

eine prinzipielle Darstellung zur Durchführung des Kreislaufverfahrens zum Reinigen von schadstoffbehafteten Textilien und

Fig. 2

eine Detaildarstellung mit thermischer Oxidationskammer, Dampferzeuger und Abluftvorwärmer zur Verwendung bei einem Verfahren gemäß der Erfindung.

Hereby show:

Fig. 1

a schematic representation of the implementation of the circulation process for the purification of contaminated textiles and

Fig. 2

a detailed illustration with thermal oxidation chamber, steam generator and exhaust air preheater for use in a method according to the invention.

As shown in Fig. 1, the laundry 1, contained in so-called cleaning cloth containers, an industrial washing machine 2 abandoned. After the washing process, the textiles are transferred to a dryer 3. After the drying process, packaging and shipping take place at a corresponding station 4.

The exhaust air 5 collected at the washing machine 2 or the dryer 3 or in the vicinity thereof is fed to an exhaust air treatment in an oxidation chamber 6. The energy released arrives at a steam generator 7. The hot steam 8 produced then serves for the energetic supply of a dirty water cleaning system 9.

The dirty water 10 is the dirty water cleaning system 9 abandoned and there preferably treated and cleaned in several stages and the output side of the dirty water cleaning system as a service or wash water 11 again available. In this way, a reduction of fresh water consumption succeeds.

With reference to FIG. 2, an embodiment for operating the oxidation chamber 6 according to the invention will now be explained.

The chamber 6 has a regulated fuel gas supply 12 and an arrangement for atomizing 13 of liquid solvent residues.

The chamber waste gas stream is fed to the steam generator 7. On the output side of the steam generator, the exhaust gas stream reaches an exhaust air preheater 14.

Fresh air 15 is mixed with exhaust air 5 via control devices and either directly to the chamber 6 or preheated by means of Abluftvorwärmers 14, the chamber 6 is supplied.

The equipped with a gas burner in the example shown chamber 6 is able to oxidize pollutants present at about 720 ° C in the exhaust air safely below clean air limits.

The chamber 6 downstream steam generator 7 cools the clean gas from about 720 ° C to 250 ° C and sets an energy output of eg 900 kW at a production capacity of the car wash of 500 to 600 kg / h cleaning cloths free.

This corresponds to a capacity of substantially 1300 kg / h of saturated steam at a pressure of 14 bar.

The exhaust air preheater 14, which is connected downstream of the steam generator 7, further cools the clean gas down to about 150 ° C. and serves to heat the exhaust air from about 35 ° C. to about 135 ° C.

With full decrease of the amount of steam during the plant operation, an increase in the clean gas temperature after the boiler is excluded. In the case of reduced or missing heat release, the exhaust air preheater is bypassed on the clean gas side in order to avoid higher temperatures in the subsequent exhaust air preheater and to prevent preignition.

In the above arrangement, the following gas consumption is to be expected:
0 g solvent / m ³ with 5000 Nm ³ / h approx. 120 Nm ³ / h with Hu (gas) = 10 kWh / Nm ³
8 g solvent / m ³ with 5000 Nm ³ / h approx. 80 Nm ³ / h with Hu (gas) = 10 kWh / Nm ³

In order to save further fuel, reference is made to the already explained possibility of injecting liquid residues into the chamber.

The following gas consumption is assumed:
30 kg / h FR in 5000 Nm ³ / h with 8 g / m ³ approx. 50 Nm ³ / h with Hu (gas) = 10 kWh / Nm ³
50 kg / h FR in 5000 Nm ³ / h with 8 g / m3 approx. 29 Nm ³ / h with Hu (gas) = 10 kWh / Nm ³
(FR = liquid residue)

In comparison to this, a directly fired steam generator consumes approx. 105 Nm ³ / h of gas with Hu (gas) = 10 kWh / Nm ³ for approx. 900 kW or 1300 kg / h of steam.

LIST OF REFERENCE NUMBERS

1

laundry

2

Washing machine

3

dryer

4

packing station

5

exhaust

6

oxidation chamber

7

steam generator

8th

superheated steam

9

Wastewater treatment plant

10

slop

11

Industrial water / wash water

12

Fuel gas supply

13

Verdüsungsanordnung

14

Abluftvorwärmer

15

fresh air

16

control equipment

Claims (7)

1. Circulation method for the environmentally-friendly cleaning of contaminated textiles, in particular industrial cleaning rags contaminated with solvent residues, whereby the articles to be cleaned are supplied to an industrial washing machine (2) and, following washing, to a dryer (3), wherein exhaust airflows (5) collected from the industrial washing machine (2) and dryer (3) are mixed with fresh air (15), guided through a preheater means (14) into a chamber (6) and oxidized there; the energy produced in chamber (6) being supplied to a steam generator (7) linked to a device for preheating the washing water and a waste water evaporation system (9), wherein evaporation and thus purifying of the waste water (10) as well as heating of the industrial water (11) thus cleaned and fed back to industrial washing machine (12) ensues with a minimum supply of external energy.
2. Circulation method in accordance with claim 1, characterized in that the heavily solvent-laden residues condensed from the exhaust airflows (5) pass to a nozzle arrangement (13) in oxidation chamber (6).
3. Circulation method in accordance with claim 1 or 2, characterized in that the solid or other residues collected in the waste water evaporation system (9) are supplied to a separate recycling.
4. Circulation method in accordance with claim 1, characterized in that the preheating means (14) is fed exhaust gas flow supplied by steam generator (7).
5. Circulation method in accordance with one of the preceding claims,
   characterized in that
   waste water evaporation system (9) comprises a filter, a centrifugal separator as well as a downstream stage with forced circulation evaporator.
6. Arrangement for realizing the method in accordance with one of claims 1 to 5, comprising: an industrial washing machine (2) and a dryer (3), an industrial washing machine and dryer exhaust collection line, connected in each case to said washing machine (2) and dryer (3) and linked to a preferably gas-heated oxidation chamber (6) via an exhaust air preheater (14), wherein mixing means is provided for the regulated supply of fresh air (15) to chamber (6), wherein the fresh air (15) mixed with the collected exhaust airflows (5) from the industrial washing machine (2) and dryer (3) is routed through exhaust air preheater (14) in chamber (6) and oxidized there, the energy released from chamber (6) furthermore passes to a steam generator (7), wherein the energy of the superheated steam generated there is supplied to a multi-stage waste water evaporation system (9) and a means for preheating the washing water (11), wherein evaporation and thus purifying of the waste water (10) as well as heating of the industrial water (11) thus cleaned and fed back to the industrial washing machine (12) ensues with a minimum supply of external energy.
7. Circulation method in accordance with claim 6, characterized by means provided in the oxidation chamber for the additional atomizing of liquid residues containing solvent.

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