EP0959173A1 - Verfahren und Maschine mit geschlossenem Kreislauf zum Waschen und/oder Trocknen von Produkten - Google Patents

Verfahren und Maschine mit geschlossenem Kreislauf zum Waschen und/oder Trocknen von Produkten Download PDF

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Publication number
EP0959173A1
EP0959173A1 EP99830283A EP99830283A EP0959173A1 EP 0959173 A1 EP0959173 A1 EP 0959173A1 EP 99830283 A EP99830283 A EP 99830283A EP 99830283 A EP99830283 A EP 99830283A EP 0959173 A1 EP0959173 A1 EP 0959173A1
Authority
EP
European Patent Office
Prior art keywords
solvent
drum
air
machine
temperature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP99830283A
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English (en)
French (fr)
Inventor
Alessandro Soffritti
Enrico Serafini
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ama Group SpA
Original Assignee
Ama Universal SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ama Universal SpA filed Critical Ama Universal SpA
Publication of EP0959173A1 publication Critical patent/EP0959173A1/de
Withdrawn legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
    • D06F43/00—Dry-cleaning apparatus or methods using volatile solvents
    • D06F43/08—Associated apparatus for handling and recovering the solvents
    • D06F43/086—Recovering the solvent from the drying air current

Definitions

  • the present invention relates to a method and closed circuit machine for washing and/or drying products.
  • the method and machine according to the present invention are designed for washing and drying any type of product, such as fabrics, metal and non-metal objects, etc.
  • a first possibility for preventing the air/solvent mixture in the drum from igniting or exploding is to reduce the concentration of oxygen O 2 in the mixture by introducing an inert gas, such as N 2 , into the drum during drying.
  • This method is disadvantageous due to the cost of the inert gas.
  • a second possibility for preventing the air/solvent mixture in the drum from igniting or exploding is to keep the temperature of the air/solvent mixture in the drum below a safety level, for example 15 o C below what is known as the "flash point" of.the solvent.
  • Methods of this type are known, as described in the preamble to claim 1, which for regulating the temperature and concentration of the air/solvent mixture in the drum during drying envisage continuous measurement of the solvent concentration and the temperature of the air/solvent mixture at the outfeed of and/or inside the machine drum. These continuously measured parameters are processed by a computer so as to regulate, on the basis of this data, the heat supplied to the drum and, therefore, indirectly or directly, the temperature and concentration in the drum.
  • Measurement of the solvent concentration at a single point in the drum and/or at the drum outfeed is insufficient, since conditions are extremely turbulent and so uneven. Measurement of the concentration at a plurality of points inside and/or at the outfeed of the drum is also insufficient, since in a turbulent area it is impossible to pre-establish fixed measuring points for maximum solvent concentrations.
  • the aim of the present invention is, therefore, to overcome the above-mentioned disadvantages by providing a closed circuit method for washing and/or drying products.
  • a further aim of the present invention is to provide a simple, safe and reliable machine which efficiently implements the method according to the present invention.
  • the present invention relates to a method for washing and/or drying products 20 in a closed circuit machine, labelled 1 as a whole.
  • the products 20, which may be, for example, clothes (labelled 20), fabrics, metal or non-metal objects (labelled 20'), or any other type of products, may be placed in the machine 1 washing zone 2, which in this case takes the form of a washing drum 2, be washed with solvents, for example, flammable hydrocarbons, then dried with hot air in the drum 2.
  • the drum 2 may be used for drying only, whilst the washing is done in another machine.
  • the temperature T2 and, therefore, the solvent concentration C2, of the air/solvent mixture in the drum 2 are permanently regulated in an indirect manner during the entire product 20, 20' drying stage on the basis of the actual values of the evaporation pressure P1, measured inside the low pressure zone of the cooling circuit which constitutes the machine 1 condenser 5, and/or the temperature T1 of the air or the air/solvent mixture measured at the infeed 3 of the drum 2. This prevents the temperature T2 and, therefore, the solvent concentration C2, of the air/solvent mixture inside the drum 2 from exceeding the safety limit of the lower flash point.
  • the actual values of the evaporation pressure P1 and the temperature T1 of the air/solvent mixture at the infeed 3 of the drum 2 are kept below a preset nominal value. If the actual value of the evaporation pressure P1 and/or the temperature T1 exceed the relative preset nominal value, the heat necessary to dry the products 20, 20' is automatically reduced (or, in extreme cases, interrupted) to prevent the temperature T2 and, therefore, the concentration C2 inside the drum from exceeding the safety limit of the lower flash point.
  • the temperature T1 of the mixture is therefore measured at the infeed 3 of the drum 2 in order to regulate the amount of heat supplied to the drum 2 and used to extract the solvent from the products 20, 20' in the drum 2 by evaporation.
  • the evaporation pressure P1 is measured in order to control the condensing of the solvent evaporated from the products 20, 20' inside the drum 2.
  • a further control may be envisaged by measuring the actual value of the temperature T3 of the air/solvent mixture at the outfeed 4 of the drum 2.
  • the actual value of the temperature T3 of the air/solvent mixture must be below a preset upper limit and above a preset lower limit. If the temperature T3 is above the preset upper limit or below the preset lower limit, the heater 7 is automatically switched off, to prevent the temperature T2 and, therefore, the concentration C2, in the drum from exceeding the safety limit of the lower flash point.
  • the temperature T6 of the mixture can also be measured downstream of the condenser 5 outfeed and upstream of the machine 1 heat pump 6 infeed, to check and indirectly control the operation and status of the condensing process.
  • the machine 1 heater 7 can only be started for product 20, 20' drying when the actual value of the evaporation pressure P1 is below a preset nominal value.
  • the machine 1 Before being started, the machine 1 is calibrated, that is to say, the nominal values are set on the basis of the solvent concentration C3 in the air/solvent mixture measured at the outfeed 4 of the drum 2 in all possible operating conditions.
  • the solvent concentration C3 in the air/solvent mixture at the outfeed 4 of the drum 2 is always kept below the safety limit of the solvent lower explosion limit by adjusting the evaporation pressure P1 of the condenser 5.
  • the actual values T1, P1, T3, T6 of the parameters measured during drying of the products 20, 20' washed with the solvent are controlled using comparison means 17, for example, a control unit 17 which stores the preset nominal values.
  • control unit 17 detects that the condenser 5 evaporation pressure P1 is above the preset nominal value, or the actual temperature value T1 at the infeed of the drum 2 is above the preset nominal temperature, or the temperature T3 at the outfeed 4 of the drum 2 is above the preset nominal value, the machine 1 drying process is automatically interrupted or stopped.
  • the present invention also relates to a closed circuit machine for washing and/or drying products according to the above-mentioned method.
  • the accompanying drawing schematically illustrates the machine 1 disclosed, which comprises a washing drum 2, in which the products 20, 20' can be washed with a flammable solvent (not illustrated), for example, hydrocarbons, then dried using hot air to extract the solvent from the products 20, 20' in the drum 2 by evaporation.
  • a flammable solvent for example, hydrocarbons
  • the machine 1 is equipped with means 12, for example, located downstream of the heat pump 6 and upstream of the heater 7, for the forced circulation of the air/solvent mixture (see arrows in the figure) during product 20, 20' drying.
  • Said means 12, of the known type and so not described in detail, may be one or more fans 12 located at any point in the air circuit.
  • a condenser 5 Downstream of the outfeed 4 of the drum 2, within the machine 1 closed circuit, there is a condenser 5, to which an air/solvent mixture from the drum 2 is directed, in order to condense at least part of, and preferably most of the evaporated solvent.
  • a heat pump 6 which preheats the air containing a reduced solvent concentration or no solvent at all, and a heater 7 for heating the air, to be fed to the drum 2 again at a temperature T1 sufficient to extract the solvent from the products 20, 20' in the drum 2 by evaporation.
  • the condenser 5, heat pump 6 and heater 7 are of the known type and so are not described in detail.
  • a first temperature control preferably using a thermostat 9 to measure the actual temperature T3 of the air/solvent mixture during product 20, 20' drying.
  • the machine 1 is fitted with a pressure gauge 13, designed to measure the actual evaporation pressure P1 values of the condenser 5.
  • the control unit 17 is designed to compare the actual evaporation pressure P1 values of the condenser 5 and the temperature T3 of the air/solvent mixture at the outfeed 4 of the drum 2, measured during product 20, 20' drying, with relative preset nominal values. If at least one of said actual values is above the relative preset nominal value, the control unit 17 automatically stops product 20, 20' drying.
  • control unit 17 is designed to automatically stop product 20, 20' drying when, after a given period has elapsed, the actual temperature value T3 is below a second preset nominal value which defines the lower limit for the temperature T3. This is because, after an unsuitable centrifuge cycle, inside the drum 2 at the start of the product 20, 20' drying stage the drum 2 may contain too much solvent. As a result, the value T3 measured at the outfeed 4 of the drum 2 would be too low.
  • control unit 17 can automatically stop product 20, 20' drying when the actual evaporation pressure value P1 is below a second preset nominal value which defines a lower limit for said pressure P1. This may occur when the condenser 5 contains no coolant. As a result, the pressure value P1 measured in the condenser 5 cooling circuit would be too low.
  • the machine 1 therefore operates only when the respective condenser 5 actual evaporation pressure value P1, temperature value T1 and temperature value T3 are not above the preset nominal values.
  • the machine 1 preferably has a second thermostat 16 for measuring the temperature T6 of the mixture downstream of the condenser 5 and, therefore, before the infeed of the heat pump 6, so as to indirectly control the operation and status of the condenser 5 and the ventilation system 12.
  • the machine 1 made according to the present invention has a sensor 10, 11 for measuring the solvent concentration C1, C3 in the air/solvent mixture at the infeed 3 and outfeed 4 of the drum 2, in order to preset the nominal values such as the condenser 5 evaporation pressure P1 and the temperature T3 of the air/solvent at the outfeed 4 of the drum 2.
  • the solvent concentration C1 in the air/solvent mixture at the infeed 3 of the drum 2 is, obviously, significantly lower than the solvent concentration C2 at the outfeed 4 of the drum 2, since the condenser 5 condenses at least part of the evaporated solvent in the air from the drum 2.
  • a solvent filter element which increases the condensation, labelled 14 as a whole, with which the concentration of the solvent in the air/solvent mixture from the condenser 5 can be further reduced.
  • the filter element 14 consists of at least one wire (not illustrated), constituting a mechanical barrier designed to prevent drops of solvent from passing through the filter element 14 by causing the drop of solvent to stick to one or more portions of the wire in the filter element 14.
  • the filter element 14 may consist of at least one wire wound in a disorderly way, forming an irregular surface designed to cause the solvent in the air/solvent mixture to condense, and irregular gaps which allow the passage of air from the condenser 5 to the heat pump.
  • the condenser 5 is preferably designed to cool the filter element 14 as well.
  • the irregular surface of the wire extends in a disorderly way on various planes and is three-dimensional.
  • the filter element 14 may also consist of at least one wire wound in an orderly way, forming a regular surface designed to cause the solvent in the air/solvent mixture to condense, and gaps for the passage of the air.
  • the regular surface of the wire extends in an orderly way on various planes and is three-dimensional.
  • the filter element 14 preferably consists of at least one tape-shaped stainless metal wire.
  • the filter element 14 makes it easy to obtain an air/solvent mixture with a solvent concentration that is lower than that in the mixture arriving from the condenser 5 alone.
  • the solvent condensed in the condenser 5 and/or filter element 14 is carried to a separator 18 then stored in a solvent collection tank 15.
  • the method and the machine according to the present invention therefore, have a system designed to control and regulate the temperature T2 and, indirectly, the solvent concentration C2 in the drum 2 in a simple, precise, reliable way.
  • the control unit 17 automatically stops the drying process to prevent it from exceeding the lower explosion limit and/or flash point of the solvent in the drum 2.
  • a second control may be envisaged, using the thermostat 16 which measures the temperature T6 of the air upstream of the heat pump 6, to check, before the infeed 3 of the drum 2, whether there is any unacceptable rise in the actual air temperature.
  • the temperature T1 at the infeed 3 of the drum 2 is then measured by the thermostat 8, to prevent overheating of the air supplied to the drum 2, and to regulate the amount of heat supplied to the drum 2 in order to extract the solvent from the products 20, 20' by evaporation.
  • thermostats 8 and two thermostats 9 are preferably used at the infeed and outfeed 4 of the drum 2.
  • the present invention may be subject to numerous variations, all encompassed by the original design concept. Moreover, all parts may be substituted with technically equivalent elements.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Detergent Compositions (AREA)
  • Cleaning By Liquid Or Steam (AREA)
  • Paper (AREA)
  • Accessory Of Washing/Drying Machine, Commercial Washing/Drying Machine, Other Washing/Drying Machine (AREA)
EP99830283A 1998-05-15 1999-05-10 Verfahren und Maschine mit geschlossenem Kreislauf zum Waschen und/oder Trocknen von Produkten Withdrawn EP0959173A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT98BO000317A IT1300040B1 (it) 1998-05-15 1998-05-15 Procedimento ed impianto a circuito chiuso per il lavaggio e/o l'asciugatura di prodotti.
ITBO980317 1998-05-15

Publications (1)

Publication Number Publication Date
EP0959173A1 true EP0959173A1 (de) 1999-11-24

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Family Applications (1)

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EP99830283A Withdrawn EP0959173A1 (de) 1998-05-15 1999-05-10 Verfahren und Maschine mit geschlossenem Kreislauf zum Waschen und/oder Trocknen von Produkten

Country Status (2)

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EP (1) EP0959173A1 (de)
IT (1) IT1300040B1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1162302A2 (de) * 2000-06-06 2001-12-12 DONINI INTERNATIONAL S.p.A. Verfahren und Vorrichtung zur Sicherheitssteuerung des Trocknenzyklus einer Trockenreinigungsmaschine die mit Kohlenwasserstofflösungsmittel reinigt

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3949485A (en) * 1972-08-30 1976-04-13 Firma Bowe Bohler & Weber Kg Method of and apparatus for drying articles in contact with an organic solvent
FR2476160A3 (fr) * 1980-02-18 1981-08-21 Maestrelli Spa Machine perfectionnee de nettoyage a sec de vetements
EP0053727A1 (de) * 1980-11-25 1982-06-16 Multimatic Maschinen GmbH. & Co. Trockenreinigungsvorrichtung
JPH05277287A (ja) * 1992-03-31 1993-10-26 Sanyo Electric Co Ltd 溶剤回収式乾燥機の運転方法
US5367787A (en) * 1992-08-05 1994-11-29 Sanyo Electric Co., Ltd. Drying machine
EP0679754A2 (de) * 1994-04-25 1995-11-02 Lutz Solbach Verfahren und Vorrichtung zur Behandlung von textilem Warengut während des Trocknungsprozesses
US5689848A (en) * 1995-10-05 1997-11-25 Satec Gmbh Method and apparatus for dry cleaning textiles

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3949485A (en) * 1972-08-30 1976-04-13 Firma Bowe Bohler & Weber Kg Method of and apparatus for drying articles in contact with an organic solvent
FR2476160A3 (fr) * 1980-02-18 1981-08-21 Maestrelli Spa Machine perfectionnee de nettoyage a sec de vetements
EP0053727A1 (de) * 1980-11-25 1982-06-16 Multimatic Maschinen GmbH. & Co. Trockenreinigungsvorrichtung
JPH05277287A (ja) * 1992-03-31 1993-10-26 Sanyo Electric Co Ltd 溶剤回収式乾燥機の運転方法
US5367787A (en) * 1992-08-05 1994-11-29 Sanyo Electric Co., Ltd. Drying machine
EP0679754A2 (de) * 1994-04-25 1995-11-02 Lutz Solbach Verfahren und Vorrichtung zur Behandlung von textilem Warengut während des Trocknungsprozesses
US5689848A (en) * 1995-10-05 1997-11-25 Satec Gmbh Method and apparatus for dry cleaning textiles

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 018, no. 058 (C - 1159) 31 January 1994 (1994-01-31) *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1162302A2 (de) * 2000-06-06 2001-12-12 DONINI INTERNATIONAL S.p.A. Verfahren und Vorrichtung zur Sicherheitssteuerung des Trocknenzyklus einer Trockenreinigungsmaschine die mit Kohlenwasserstofflösungsmittel reinigt
EP1162302A3 (de) * 2000-06-06 2003-01-02 DONINI INTERNATIONAL S.p.A. Verfahren und Vorrichtung zur Sicherheitssteuerung des Trocknenzyklus einer Trockenreinigungsmaschine die mit Kohlenwasserstofflösungsmittel reinigt
US6609310B2 (en) 2000-06-06 2003-08-26 Donini International S.P.A. Method and apparatus for safety control of the drying cycle in hydrocarbon-solvent dry-cleaning machines

Also Published As

Publication number Publication date
IT1300040B1 (it) 2000-04-04
ITBO980317A1 (it) 1999-11-15
ITBO980317A0 (it) 1998-05-15

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