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
  • D06F39/00—Details of washing machines not specific to a single type of machines covered by groups D06F9/00 - D06F27/00 
  • D06F39/02—Devices for adding soap or other washing agents
  • D06F39/022—Devices for adding soap or other washing agents in a liquid state

Definitions

• the present invention relates to a process and a device for dosing' detergent compositions into a washing machine. More in particular, it relates to a process and a device for dosing detergent compositions which are in the form of liquids, pastes or gels,of which the viscosity increases when they are brought into contact with small amounts of water.
• non-aqueous liquid detergent com ⁇ positions which undergo a drastic viscosity increase upon contact with water, or even form gels. Crystallization of solid components may also occur under such conditions. Examples of such non-aqueous liquid detergent compositions are given in the European patent application 266,199 (Unilever) .
• an object of the present invention to provide a process for dosing a detergent composition which is in the form of a liquid, paste or gel, of which the vis ⁇ cosity increases when it is brought into contact with small amounts of water, into a washing machine, which process overcomes one or more of the above drawbacks.
• the present invention provides a process of the above mentioned kind, whereby the detergent, composition is transported from a container for holding the composition to the washing machine via a conduit and a valve, characterised in that
• said valve is a dosing valve including a product inlet, a product chamber, a product outlet and a plunger, said plunger being electromagnetically or pneumatically actuated;
• said valve is opened and closed by quick movement of the plunger in a direction along its axis away from respec ⁇ tively into the product outlet.
• the process of the present invention appears to be surprisingly simple and reliable, resulting in reduced installation cost with regard to the dosing system required.
• the dosing valve applied therein was found to effectively prevent the risk of such contact between deter ⁇ gent composition and small amounts of water that blocking could occur.
• Reason is that the closing action of the valve is performed in such a short time period and with such force that water is prevented from entering the valve and that the product outlet of the valve is cleaned during the closing action.
• no clogging of detergent material can take place inside the dosing valve, because there are no "dead" holes or zones in the product outlet area of the valve.
• the process of the invention may be used for dosing deter ⁇ gent material into both domestic and industrial washing machines.
• the plunger in the dosing valve applied therein is, preferably, pneumatically ac- tuated.
• the plunger is desirably connected to a piston which is movable inside a hollow air- filled cylinder, whereby the internal volume of said cylinder is divided by the piston into two partial volumes, and whereby each of these partial volumes is connected to means for supplying compressed air thereto and to means for deaerating them. Consequently, the dosing valve is opened and closed by supplying compressed air to the first respectively the second of said two partial volumes and by simultaneously deaerating the other partial volume.
• the air-filled cylinder containing the movable piston preferably, comprises a spring which is connected to the piston.
• This spring was found to be useful as it accelerates the closing action of the dosing valve.
• the spring also makes the dosing valve fail-safe: it closes the valve automatically at a power failure or a malfunctioning compressed air supply system, thus ensuring a safe and reliable operation of the dosing valve.
• the air-filled cylinder enables the piston to move along the axis direction of the plunger to which it is connected, when the dosing valve is opened or closed by the action of the compressed air on to the piston.
• the detergent composition flowing out of the dosing valve may be transported directly into the washing machine.
• the detergent composition is preferably injected into the washing machine at a level below the water level inside said machine in order to diminish the risk of undesirable viscosity increases due to humidity uptake by the detergent composition at the product outlet area of the dosing valve. This risk is diminished because at a level below the water level any product residue formed at the outside of the outlet of the valve is rinsed off by the wash liquor present in the washing machine.
• Another advantage of injecting the detergent composition below the water level is that, as a result, a more homogeneous distribution thereof in the wash liquor will occur; when a fabric washing machine is used this will result in reduced risk of textile damage.
• Adequate dilution is obtained in the mixing tank at a weight ratio of detergent composition to water being in the range of from about 1:5 to about 1:20.
• the water flow into said tank is desirably controlled.
• the mixing tank used for dilution of the detergent com- position may have any shape or size. It has effectively an internal volume of 50-150 litres, and is desirably equipped with a level detection device for controlling the level of the diluted detergent product present therein. Furthermore, the mixing tank has effectively a sloped shape at its bottom side, and is preferably equipped with a cir ⁇ culation system including a circulation pump, preferably a centrifugal pump, in order to obtain a homogeneously diluted detergent product. The content of the mixing tank is effectively circulated at a rate of from 4-10 times its internal volume per minute. The outlet of the mixing tank is usually connected with one or more pumps for transporting the diluted detergent product to one or more washing machines.
• the above-described dosing system including a mixing tank can be suitably applied for carrying out the process of the invention.
• a more simple system not involving a mixing tank was also found to be very safe and reliable when carying out the process of the invention for dosing detergent material into a double-drum industrial tunnel washing machine.
• the dosing process of the invention can be effectively applied for dosing detergent material to all double-drum sections and the funnel of an industrial tunnel washer.
• a second dosing valve according to the present invention may be effectively applied as a flow-check or sampling valve, by connecting said second valve to the conduit through which the detergent composition is pumped from a container for holding it to the first dosing valve.
• the dosing system used for the process of the present invention should be controlled regularly on its pump delivery per unit of time. Sometimes, there is also the need to tap some product for other pur- poses. Normally, a hand-operated 3-way valve is used as a flow-check or sampling valve. However, due to the nature of the detergent composition applied, a second dosing valve according to the invention is preferably used as flow check and sampling valve in the dosing system suitable for ap- plying the process of the invention.
• the main reasons why the dosing valve used in the process of the present invention is also very suitable for use as a sampling or flow-check valve are the following: (i) It prevents contamination of the detergent product with humid air;
• detergent products which can be suitably dosed by applying the process of the present invention, are the non-aqueous liquids disclosed in the European patent ap ⁇ plication 543,443 (Unilever).
• Figure 1 shows schematic views of the dosing valve used in the process of the present invention, in the closed (A) and in the open (B) position.
• Figure 2 gives a schematic view of a system suitable for the process of the invention, showing a dosing valve for injecting detergent product into a washing machine and a flow check/sampling valve.
• FIG. 3 gives a schematic view of a system suitable for the process of the invention, showing a mixing tank for diluting the detergent material to be dosed into a washing machine.
• the dosing valve shown in Figure 1 comprises a product section including a product inlet (1) , a product chamber (2) , and a product outlet (3) .
• This product section also contains part of a plunger (4) which is connected to a piston (5) .
• This piston is movable in a direction along the axis of the plunger inside an air containing cylinder (6) , by applying air on one or the other side of the piston.
• Figure 1 (A) depicts the closed position of the dosing valve, which position is obtained by injecting compressed air into the air containing cylinder by way of nozzle (7b) .
• This compressed air pushes the piston and plunger into a valve seat near the outlet of the dosing valve.
• the part of the internal volume of the cylinder (6) which is situated on the other side of the piston is quickly deaerated via nozzle (7a) .
• This closing action of the nozzle is accelerated by the action of spring (8) which is attached to the piston and positioned inside the cylinder.
• This spring (8) has a second important function: at power failure or malfunctioning of the compressed air supply system the valve closes automatically by means of this spring, thus ensuring a fail-safe and reliable operation.
• the dosing valve is opened again by injecting compressed air into the air cylinder via nozzle (7a) , thus causing the plunger (4) to move out of the outlet valve seat. Simul ⁇ taneously, the air volume (6b) at the other side of the piston is quickly deaerated via nozzle (7b) . In the opened position of the valve, as shown in Figure 1(B), product can be dosed.
• Spring (9) is present for positioning the sealings between the product part and the air cylinder part of the dosing valve.
• the hole in the valve housing and situated close to this spring can be used to inspect these sealings and to drain product in case of a leakage.
• FIG. 2 shows a container (10) in which a non-aqueous liquid detergent product (NAL) is stored.
• NAL non-aqueous liquid detergent product
• the product is transported by the action of a pump (11) via a dosing valve .(12) according to the present invention into a washing machine (13) .
• Pressure switch (11a) is included as a safeguarding measure: with this switch, the product line from pump (11) to dosing valve (12) is monitored and protected against overpressure.
• a second valve (14) is shown in this Figure 2, which valve is equal to the dosing valve (12) in respect of its configuration and operation.
• Both valves are connected to a source of compressed air (15) having a working pressure of 6 Bar, via air switch elements (16) .
• These switch elements monitor the pressure of the compressed air (15) and safeguard the operation of valves (12) and (14) thereby prohibiting their use at a compressed air pressure below 3 barg.
• FIG.3 shows a mixing tank (17) into which non-aqueous liquid detergent product (NAL) is dosed by the dosing valve (12) .
• the mixing tank is also filled with water for diluting the NAL product, via water flow indicator (20) .
• the water flow into the mixing tank is controlled in order to obtain a constant weight ratio of NAL to water.
• the mixing tank is equipped with a level detecting device (19) and a circulation system including a centrifugal pump (18) . This circulation system ensures that the NAL product is homogeneously diluted before being transported by pump (21) to a washing machine (13).

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Detail Structures Of Washing Machines And Dryers (AREA)
• Detergent Compositions (AREA)
• Washing And Drying Of Tableware (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8214019

Family Applications (1)

Country Status (8)

Cited By (3)

Families Citing this family (1)

Citations (6)

• 1994
  • 1994-06-30 EP EP94919675A patent/EP0711367B1/en not_active Expired - Lifetime
  • 1994-06-30 WO PCT/EP1994/002150 patent/WO1995004183A1/en active IP Right Grant
  • 1994-06-30 ES ES94919675T patent/ES2114205T3/es not_active Expired - Lifetime
  • 1994-06-30 AU AU70738/94A patent/AU694435B2/en not_active Ceased
  • 1994-06-30 DE DE69409240T patent/DE69409240T2/de not_active Expired - Fee Related
  • 1994-06-30 BR BR9407105A patent/BR9407105A/pt not_active IP Right Cessation
  • 1994-07-11 ZA ZA945004A patent/ZA945004B/xx unknown
• 1996
  • 1996-01-29 FI FI960386A patent/FI960386A0/fi unknown

Patent Citations (6)

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