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EP-4054983-B1 - FILTRATION DEVICE FOR FILTERING A LIQUID AND METHOD FOR FILTERING A LIQUID

EP4054983B1EP 4054983 B1EP4054983 B1EP 4054983B1EP-4054983-B1

Inventors

  • BUNNEMANN, Phillip
  • HAGEN, THOMAS

Dates

Publication Date
20260506
Application Date
20200914

Claims (6)

  1. Filtration device (1) for filtering a liquid, the filtration device (1) comprising • a storage container (10) for unfiltered liquid, • a mounting (11) for a filter container (30), • a filter container (30) filled with a filter medium (31) being mounted in the mounting (11), wherein a filtering performance, corresponding to a ratio of an amount of substances filtered from the liquid over an amount of liquid being filtered, improves with increasing time of interaction between the liquid and the filter medium, • a first sensor (40) that is configured to determine a first value y 1 of a parameter of the unfiltered liquid, wherein the first sensor (40) is an electric, electronic or electrochemical sensor that generates electric signals depending on the measured parameter, • a pump (20) fluidically coupled to the storage container (10) and communicatively coupled to the first sensor (40) and • a control unit (44), wherein the control unit (44) comprises a memory unit (46) and a processing unit (48) and is communicatively coupled to the first sensor (40) and the pump (20), wherein the pump (20) is configured to generate a gauge pressure P g in the storage container (10) during the filtering of the unfiltered liquid, characterized in that the filtration device (1) comprises a second sensor (42), which is configured to determine a second value y 2 of the parameter of the filtered liquid and is an electric, electronic or electrochemical sensor that generates electric signals depending on the measured parameter, in that the pump (20) is communicatively coupled to the second sensor (42), and is configured to reduce the gauge pressure P g during the filtration process if a parameter relation D = y 1 - y 2 or D = 1 − y 2 y 1 is lower than a preset first specific parameter relation D 1 , in that the control unit (44) is communicatively coupled to the second sensor (42), and in that the processing unit (48) is configured to set the pumping capacity of the pump (20) according to the parameter relation D.
  2. Filtration device (1) according to claim 1, characterized in that the liquid is water and the parameter is the carbonate hardness of the water.
  3. Filtration device (1) according to claim 1 or 2, characterized in that the pump (20) is configured to press the liquid or a gas into the storage container (10) in order to generate the gauge pressure P g .
  4. Filtration device according to any of claims 1 to 3, characterized in that the filtration device (1) comprises an indicating device for indicating the current pumping capacity of the pump (20) and/or the current filter medium performance.
  5. Method for filtering a liquid in a filtration device (1) according to any of the claims 1 to 4, wherein a liquid to be filtered flows through a filter medium (31) and leaves the filter medium (31) as a filtered liquid, wherein a filtering performance, corresponding to a ratio of an amount of substances filtered from the liquid over an amount of liquid being filtered, improves with increasing time of interaction between the liquid and the filter medium, characterized in that the liquid to be filtered is subjected to a gauge pressure P g , wherein a parameter characterizing the quality of the liquid is continuously monitored, wherein a first value y 1 of the parameter is measured in the unfiltered liquid and a second value y 2 of the parameter is measured in the filtered liquid, wherein a parameter relation D = y 1 - y 2 or D = 1 − y 2 y 1 is continuously determined, and wherein the gauge pressure P g is reduced, at D < D 1 , wherein D 1 is a preset first specific parameter relation.
  6. Method according to claim 5, characterized in that the gauge pressure Pg is increased at D > D2, wherein D2 is a preset second specific parameter relation.

Description

The invention relates to a filtration device for filtering a liquid and a method for operating a filtering of a liquid. Filtration devices of the above-referenced kind are being used as water filters for everyday use in households, which is why they are also called table water filters. They are primarily used for clearing tap water of unwanted substances. Among these substances are chloride and carbonate hardness builders such as calcium and magnesia, but also lead, which finds its way into tap water through the use of lead pipes, especially in older houses. Such filtration devices often utilize a filter medium. For example, the filter medium may be provided in a filtration cartridge which may be exchanged after the performance of the filter medium starts to decrease or in a filter medium container, wherein the filter medium itself is exchangeable. After a while, the filter medium of such a filtration device will reach the end of its lifetime. The lifetime of a filter medium is usually defined by the filtration performance of the filter medium. If the filtration performance decreases to a minimum threshold value, the end of the lifetime of the filter medium is reached. Within the state of the art, it is common to signal the end of the lifetime of the filter medium. For example DE 10 2014 102 583 A1, US 6,024,867 and US 2016/0121246 A1 disclose a device and methods for counting the number of times the filtration cartridge is used. After a defined number of uses, the device signals the user to replace the filtration cartridge. US 2012/0217197 A1, DE 69 909 760 T2 and DE 10 2007 062 925 A1, EP 2 471 745 A1 disclose methods for determining the end of the lifetime of a cartridge by using erodible or soluble elements, e.g. in form of tablets. Upon dissolving, the erodible or soluble elements either activate a signaling element or decrease the flow of liquid through the filter medium. From US 2013/0199974 A1 a device for purifying a liquid is known. The device includes a collecting vessel for an unpurified liquid, a collecting vessel for a purified liquid, a replaceable filter module filled with a filter material and an automatic means including a pneumatic pump for timed injection of air into the collecting vessel for the unpurified liquid. A positive air pressure within the range of 0.1 - 1.0 bar above the level of the unpurified liquid is maintained throughout the entire filtration cycle. The device particularly comprises a liquid level sensor that is used for automatic switching off the pneumatic pump when the unpurified liquid reaches the minimum level. The device is configured for monitoring or adjusting the pressure within the collecting vessel for the unpurified liquid to have a uniform and stable flowing of a liquid through the filter material. Coming from US 2013/0199974 A1 the problem to be solved by the invention is to provide an improved filtration device for filtering a liquid and a method for operating the filtration device with an increased filter performance. The problem is solved by the features of the independent claims. In a first aspect, the invention relates to a filtration device for filtering a liquid. The filtration device comprises a storage container for unfiltered liquid, a mounting for a filter container, a filter container filled with a filter medium being mounted in the mounting, a first sensor that is configured to determine a first value y1 of a parameter of the unfiltered liquid and a pump fluidically coupled to the storage container and communicatively coupled to the first sensor, wherein the pump is configured to generate a gauge pressure Pg in the storage container during the filtering of the unfiltered liquid. The filtration device comprises a second sensor which is configured to determine a second value y2 of the parameter of the filtered liquid. The pump is communicatively coupled to the second sensor and is configured to reduce the gauge pressure Pg during the filtration process, if a parameter relation D of the first value y1 and the second value y2 is lower than a preset threshold, which is a preset first specific relation D1. The parameter relation D preferably means D = y1 - y2 or D=1−y2y1. Preferably, the filtration device can have a free outlet or comprise a container for the filtered liquid. The pump is configured to generate gauge pressures between 0,01 bar and 2 bar. Preferably, the storage container is a pressure container, which can withstand 1.2 bar, preferably 1.5 bar and especially 2.0 bar gauge pressure. Within the scope of this invention, the term "fluidically coupled" means that the filtration device comprises means, e.g. connectors, pipes or lines, for transporting any liquid or gas from one component to another. The mounting for the filter container, which preferably is a filter cartridge containing the filter medium, makes it easy for the user to exchange the filter medium or the container. On one hand, the filter container may, for example, be formed as