DE4343488A1 - Device for cleaning textiles - Google Patents

Description

1. Exit and problem

In the past, textiles were mainly cleaned with the Solvents CFC 113 and perchlorethylene.

CFC 113 has been under the 2nd Federal Immission Control Ordinance (2nd BImSchV) since 01/01 No longer permitted in Germany in 1993. Exemptions for use this product will run until the end of 1994.

The pollution control regulations for perchlorethylene have been drastically tightened. The tightening of these regulations means that Per machines today about 80% are more expensive than 5 years ago and that these machines are also because of the necessary ancillary facilities serving to protect against immission (activated carbon plant) also need significantly more space.

CFC 113 machines had one due to the use of a highly volatile solvent Batch duration of about 30 minutes. Perchlorethylene machines come under Consideration of the immission control measures of the 2nd BImSchV on a Batch duration of around 60 minutes. That means replacing a CFC 113 machine by a Per machine while maintaining the previous capacity one machine with double the loading weight required.

For some time now, textile cleaning instead of being biodegradable Halogenated hydrocarbons also used pure hydrocarbons (KWL), which in Soil and atmosphere are biodegraded within a few days. The batch duration for these KWL machines is also around 60 minutes.

In addition to the high financial burden on the textile cleaner caused by the Retrofitting to new machines is the opposite of Old machines greatly increased space requirements a serious problem.  

This leads especially to shop cleaning in good business locations where the Store space is limited and extremely expensive, with the problem of retrofitting Space is no longer possible. A reduction in machine capacity would make the entire operation uneconomical.

The outsourcing of cleaning to a central company and the conversion of the previous cleaning company in a city location in a collection point brings clearly extended delivery times, higher costs and worse because of the transport Qualities. The previous business cannot be continued in this way.

Hence the need to use textile cleaning machines in the future given capacity despite the prescribed additional Environmental protection devices to build cheaper and smaller.

2. State of the art

Today's machines are set up so that in the treatment drum soiled textile goods are first cleaned in the solvent and then in the same drum is dried over a recirculation system so that the goods are ready to iron can be removed.

In the circuit for the liquid solvent that is needed for cleaning Filters and a distillation system to regenerate the solvent installed.

The drying system is a recirculation system in which air is heated from the outside. These Air is used to evaporate the solvent over the drum with the cleaned and solvent-moist textile material and then passed over a cooler, in which the solvent is condensed out. This solvent runs into the cycle back. The cooler for condensing out the solvent is equipped with a Chiller operated, the waste heat via a heat exchanger the air flow is fed again. An auxiliary air heater that heats with steam or electrically will bring the drying air back to the drying temperature before it enters the Cleaning drum is returned.

In such a machine, cleaning and drying are carried out one after the other.  

To save money and space, it is common today where there are two in one company Cleaning machines are available, these two machines with a common one Distillation to regenerate the solvent. Otherwise, both are Machine independent systems, each with a solvent circuit and Drying system.

When cleaning with perchlorethylene a must in the machine air after the 2nd BImSchV Limit of 2 g of solvent per cubic meter of air can be reached before the Machine may be unloaded. This low value is said to be the residual amount of solvent keep low in the removed goods. For that, it becomes the end of the batch Drying system switched off and a separate air flow that over a Activated carbon filter is cleaned, passed through the drum. This process for Batch end takes approx. 5 min.

This results in a characteristic batch course roughly as follows:

• - Loading the drum + compensation time: 2 min.
• - Cleaning in perchlorethylene 15 min.
• - Spin 5 min.
• - drying 30 min.
• - Solvent reduction in machine air and goods over activated carbon 5 min.
• - Unloading the drum + compensation time: 3 min.
• - total time 60 min.

If the cleaning machine is operated with hydrocarbons (paraffins with a Flash point above 55 ° C and thus a boiling point above 185 ° C), see above the basic process of cleaning and drying is the same.

Since hydrocarbons are flammable products with defined explosion limits, the process is advantageously operated under inert gas.

Here nitrogen is used, which is obtained from air through an adsorption system becomes. Inertisation is especially necessary for drying because the Dry temperature is always higher than the flash point. Below the flash point the vapor pressure of the solvent is so low that economical drying times are not would be achievable.  

The drying process is carried out at KWL at a higher temperature than at Perchlorethylene because the high-boiling hydrocarbons at a given temperature have a vapor pressure that is approximately 50 times lower than perchlorethylene.

At the higher temperatures used, drying times of around 30 Minutes reached. The activated carbon plant for final cleaning of the cleaned goods is at No hydrocarbons required.

In hydrocarbon cleaning, however, the machine air must be loaded after the Machine with fresh goods can be exchanged for nitrogen. That happens expediently before solvent is added to the machine for cleaning. This contains the air from the machine that is displaced by the nitrogen and after is blown outside, no solvent.

This avoids any emission of solvents.

The typical batch process in such a machine is as follows:

• - Load the machine for 1 min.
• - Inert 3 min.
• - cleaning 20 min.
• - Spin 5 min.
• - drying 30 min.
• - unloading 1 min.
• - total time 60 min.

The hydrocarbon solvent is also regenerated by distillation technology. The Distillation is carried out in a vacuum and in a different one from perchlorethylene Process.

However, this method is of no interest for the present application.

It has been around for a long time to save investment on the machine and space usual to build reloading machines (transfer systems). Here is in one "Washing machine" for solvents that only the filter circuit and the distillation system contains, cleaned. The batch duration for this sub-process is about 20 minutes After spinning, the goods are reloaded into a dryer which is equipped with a  Air circulation system and equipped with solvent recovery through condensation is. This dryer has a drying time of around 30 minutes.

With such an arrangement, ideally about twice as much goods be enforced as in a machine of the same size, in which one after the other Drum is cleaned and dried.

Transhipment technology is not with perchlorethylene because of the emission of the solvent allowed.

Hydrocarbon solvents can be reloaded and become Machines offered.

The disadvantage of the process is the reloading process, which involves solvent Spin-dry goods manually reloaded from the "washing machine" into the dryer becomes.

The batch time of the dryer extends beyond the pure drying time because the air in the dryer is either exchanged for nitrogen after loading (Inertization) or removed (vacuum operation).

Reloading machines are cheaper and in terms of the same throughput capacity require less space than combined cleaning and drying machines (dry-to-dry machines).

3. Arrangement according to the invention 3.1 Basics

The arrangement according to the invention realized by the special structure of a 2-drum machine the economic advantages of reloading machines without must be reloaded. This makes this machine for perchlorethylene and for Hydrocarbons can be used in the same way.

The basic structure of the machine consists of two drum modules with one common dry air and solvent system.  

Like a normal single machine, the drying system consists of an air duct with fan, the condensation system for the solvent and the air heaters. Branches from this system with lockable branches, however, allow the dry air either through one or the other cleaning drum.

The solvent circulation system is the same for both drum modules usable.

So this machine arrangement contains, like a single machine, or also like a Transfer system with "washing machine" and dryer, only one tank system, one Solvent cycle with filters and distillation, a dry cycle with Heat pump, fan and heating units, but two treatment drums. in the Unlike the reloading system, the goods are cleaned in each of the drums and dried and can be removed ready.

The basic structure of such an arrangement, FIG. 1.

The view shows the common drying system, which can be connected either to drum 1 or drum 2 via the two 3-way arrangements 14 and 21 .

3.2 Arrangement for perchlorethylene

Fig. 2 shows a schematic overview of the material cycles of the double drum machine for operation with perchlorethylene.

Three tanks 11 , 12 and 13 for used and pure solvent are arranged for storing the solvent.

During the cleaning process, the solvent is supplied to the drums 1 and 2 via the pump 5, optionally via the filters 6 or 7 and the valves 31 and 28 . The solvent is sucked in again by the pump 5 via the needle catcher 3 or 4 and the valves 29 or 30 .

At the end of the cleaning process, the solvent is pumped into the tank 11 or, in the case of high contamination, into the still 8 for reprocessing. The redistilled solvent from the still is condensed in the distillate cooler 9 and separated from the water in the water separator 10 . The pure solvent goes from there to the clean tank 13 and is available for the next batch.

In order to dry the goods in the drum after cleaning, an air flow is generated by the fan 17 , conveyed via the valve arrangement 18 to the air heater 19 and from there via the auxiliary air heater 20 and the valve arrangement 21 either to the drum 1 or to the drum 2 . The dry air laden with solvent is conveyed from drum 1 or drum 2, depending on the position of the valve arrangement 14, via the fluff filter 15 to the cooler 16 and again to the blower 17 .

The cooler 16 for condensing the solvent and the air heater 19 for reheating the cooled air stream can be operated as the cold and the warm side of a heat pump.

At the end of the batch, the last remaining solvent must be removed from the textile material and the machine air with pure circulating air. For this purpose, air is pressed in a separate circuit by fan 23, either via valve 24 to drum 1 or via valve 25 to drum 2 .

This air, which is practically free of solvent, evaporates the remaining solvent from the textile material in the respective drum. The air then flows from drum 1 via valve 26 or from drum 2 via valve 27 to activated carbon filter 22 , is cleaned there and flows again via fan 23 to the respective drum.

After drying, the items to be cleaned should be cooled from the drying temperature of around 60 ° C to a temperature between 40 and 50 ° C. This is done in such a way that the dry air after the fan 17 bypassing the two air heaters 19 and 20 at the 3-way branch 18 is passed directly to the 3-way branch 21 and from there into the drum 1 and 2 , respectively. This cooled air quickly cools the textile goods.

The arrangement shows that there is only one drying system for both drum modules with hot air, an activated carbon system for fine cleaning at the end of a batch and a Solvent circulation system with filters and distillation is in place. The process is like this arranged that with one hour batch time and 30 minutes drying time one each of the two drums the drying system and the other drum the solvent Circulation system for cleaning or the activated carbon system for fine air cleaning used. The drying system is also not used for loading and unloading the drum needed.

This allows the 2 listed batch process are carried out, the loading and unloading of the drums 1 and 2 are each offset by 30 minutes.

The following operational sequence is an example:

As the indicated values show, the drying process is 50% of the total Batch time is the time-defining sub-step.

With this arrangement, it advantageously results that in the part of the sequence, where the drying system is not needed, not just loading and unloading and that Clean, but also the fine cleaning of dry air and goods via the Activated carbon can be carried out after drying.

Textile cleaning with hydrocarbons becomes similar over time Process carried out as for textile cleaning with perchlorethylene.

3.3 Arrangement for hydrocarbon solvents (KWL)

The schematic overview of the material cycles of the double drum machine for operation with hydrocarbons Fig. 3 shows.

The three tanks 11 , 12 and 13 for used and pure solvent are arranged in exactly the same way as on the perchlorethylene machine.

Before the start of the cleaning and before the feeding of solvent into the freshly loaded drum 1 , the air is flushed out of the drum by nitrogen from the separation system 32 via valve 33 and passed outside via valve 34 . In the same way, the inerting of drum 2 from the nitrogen system 32 would take place via valves 35 and 36 .

The cleaning of the textiles with liquid solvents is carried out in the same way as for perchlorethylene in drum 1 via needle catcher 3 , valve 29 , solvent pump 5 , valve 31 to the drum. The solvent circuit in the drum 2 passes through needle catcher 4, valve 30, solvent pump 5, valve 28 to the drum 2 back.

The drying cycles are the same as for operation with perchlorethylene: When drying in drum 1 , the dry air flows out of drum 1 via branch 14 , lint filter 15 , cooler 16 , blower 17 , branch 18 , heater 19 , heater 20 , branch 21 , back to Drum 1 . The drying process in drum 2 leads the air out of drum 2 via branch 14 , lint filter 15 , cooler 16 , fan 17 , branch 18 , heater 19 , heater 20 , branch 21 , back to drum 2 .

The exemplary operational sequence is as follows:

In this process too, the drying process is the 50% of the batch time time-determining sub-step. In this process it is advantageous that for the Inerting the freshly loaded cleaning drum does not require the drying system is not caused by this sub-step to extend the batch time becomes.

Claims (5)

1. Device for cleaning textiles with a drying and a solvent system and a first drum module, characterized in that a second drum module alternately to the first drum module can be connected either to the drying or to the solvent system. 2. Device according to claim 1, if the solvent Halogenated hydrocarbon, especially perchlorethylene, characterized, that a solvent removal system from the air and the textiles inside the drum after the Drying alternatively with the first or the second Drum module is connectable. 3. Device according to claim 1, when the solvent is biodegradable pure hydrocarbon characterized, that a system for inerting the textiles to be cleaned and the air inside the drum optionally with the first or is connectable to the second drum module. 4. A method for operating a device according to claim 2, characterized in that
that while textiles already cleaned in the first drum module are dried by means of the common drying system,
The following process steps take place in the second drum module:
Removal of solvent residues from previously dried textiles,
Unloading the cleaned and dried textiles,
Loaded with textiles to be cleaned,
Cleaning of the textiles by means of the common solvent system,
Spinning the textiles,
and that afterwards the already cleaned textiles are dried in the second drum module by means of the common drying system, while
the method steps described above for the second drum module take place in the first drum module. 5. A method of operating a device according to claim 3, characterized in that
that while textiles already cleaned in the first drum module are dried by means of the common drying system,
The following process steps take place in the second drum module:
Unloading cleaned and dried textiles,
Loaded with textiles to be cleaned,
Inerting the textiles to be cleaned,
Cleaning of the textiles by means of the common solvent system,
Spinning the textiles,
and that afterwards the already cleaned textiles are dried in the second drum module by means of the common drying system, while
the method steps described above for the second drum module take place in the first drum module.