Patent Publication Number: US-2023144794-A1

Title: Filter candle and system comprising a filter candle for preparing water

Description:
TECHNICAL FIELD 
     The disclosure relates to a filter head and to a filter candle for treating water, which is filled with an ion exchange material. 
     The disclosure furthermore relates to a system for water treatment which comprises a filter candle with a filter candle head. The disclosure also relates to a filter head for a filter candle. 
     BACKGROUND 
     Water treatment systems which comprise a filter candle are known from practice. More particularly, BWT AG is marketing a water treatment system under the brand name “Bestmax®”. The system comprises a filter head which can be connected to an on-site water pipe. 
     A filter candle filled with an ion exchange material is connected to the filter head by a screw connection, and subsequently water is passed through the filter candle and is thereby softened. 
     In addition to softening, such filter candles can also be used to clean the water and may, for example, include activated carbon to remove germs. 
     The so treated water is in particular used in households and gastronomy for operating coffee machines and vending machines for producing hot and/or cold beverages. 
     Also, softer water can improve the taste of coffee. 
     The system described above can comprise a filter candle with a bypass, in which only part of the water is passed through the ion exchange material. The desired degree of softening can be set via an adjustable bypass flow which is not passed through the ion exchange material. In this way, the system can in particular be adapted to the water hardness which differs depending on the location. 
     For preparing beverages, the degree of hardness is in particular set between soft and medium hard. On the other hand, nearly completely softened water, in particular a total hardness of less than 0.5° dH, is undesirable. In particular the salts are extracted from the water in the case of such a strong softening, so that it would be less suitable for drinking, like fully demineralized water. 
     While soft to medium hard water is optimal for preparing hot beverages, it is optimal to use water as soft as possible for other kitchen appliances such as steam cookers, for example, in particular almost completely demineralised water, in order to prevent salt and limescale deposits. 
     In theory it would be possible to make a respective adjustment via the bypass, depending on which water is required, for example to close the bypass completely when water for a steam cooker is needed. 
     However, this is inconvenient, in particular as filter candles are often installed under the sink. 
     Furthermore, each time the change is made, the water in the line downstream of the filter candle would first have to be drained before water with the changed degree of hardness emerges. 
     SUMMARY 
     An object of the disclosure is to at least mitigate the stated drawbacks of the prior art. 
     More particularly, it is an object of the disclosure to provide a filter candle and a system for water treatment, which allows in a simple way to provide and extract water with at least two different degrees of hardness. 
     According to a further aspect, it is an object of the disclosure to provide a filter head that can be connected easily and conveniently. 
     The object is achieved by a filter candle for the treatment of water, by a system for the treatment of water, which comprises a filter candle, and by a filter head adapted for such a system according to any one of the independent claims. 
     Preferred embodiments and refinements will be apparent from the subject-matter of the dependent claims, the description and the figures. 
     The disclosure relates to a filter candle for treating water, which is adapted for being connected to a filter head. 
     More particularly, the disclosure relates to a filter candle comprising a connection head which has a thread, for example, for being coupled to the filter head. 
     The filter head is configured for on-site connection to the water pipe. 
     This makes it possible to easily remove the filter candle and to replace it by a new filter candle once the ion exchange material has been used up. 
     The filter candle comprises a housing which is filled with an ion exchange material for softening the water to be treated. 
     The ion exchange material may be an ion exchange resin in granular form, for example. It is loaded with hydrogen, for example, which is replaced by alkali and alkaline earth ions in the water. 
     The filter candle has a head with one inlet and at least two outlets. 
     The water to be treated is fed into the filter candle via the inlet. 
     When water is extracted from a consumption point, the treated water can be discharged via the outlets. 
     Water that is almost completely softened can be introduced into the filter head at a first output of the filter candle, and water that has been subjected to a different treatment step, e.g. using activated carbon, can be introduced into the filter head at a second output of the filter candle. 
     Thus, the filter candle has two outlets, and the water is treated differently inside the filter candle so as to provide a respective different degree of hardness at the two outlets. 
     The filter candle is therefore configured such that water can be extracted for use at both outlets. Hence, the inlet water is treated via both filter pathways. The inlet water is softened when being directed through at least one filter pathway. When being passed through the other filter pathway, the inlet water is either softened less than when being passed through the other filter pathway, or it is not softened at all, but merely subjected to a different water treatment. 
     According to one embodiment, this is implemented by having a bypass provided in the filter candle, which allows to mix water that has passed through the ion exchange material with water that was not passed through the ion exchange material or was passed through the ion exchange material with a shorter dwell time or over a shorter distance. 
     It is in particular contemplated that the water which can be discharged at the second outlet was mixed with the water leaving the bypass. 
     This bypass can preferably be adjusted by means of a control element, so that the degree of hardness of the water discharged at the second bypass can be adjusted. 
     The water leaving the first outlet, on the other hand, has preferably not been mixed with water from the bypass. Thus, water that can be provided at the first outlet, has been softened as much as possible by the filter candle, depending on the configuration thereof, and, similar to fully desalinated water, in particular contains so few salts and minerals that the formation of deposits in devices in which the water is evaporated, such as for instance a steam cooker, is largely avoided. The filter candle is in particular designed such that when used as intended, the hardness will be below 1° dH, preferably below 0.5° dH. 
     In one embodiment, the inlet and the second outlet are arranged coaxially at the head of the filter candle. However, it is also possible for the inlet and the second outlet to be arranged on one side of the filter candle on the same head. 
     According to one embodiment, the first outlet (with the water softened to the maximum possible degree) is arranged so as to be turnable on top of the filter head. 
     More particularly, the first outlet is in the form of a coaxial tube emerging from the top of the filter head, which is then angled to the side. 
     The tube is preferably turnable through at least 180°, most preferably through 360° about the central axis of the filter head. 
     In this way, the first outlet can easily be turned in the direction of the tapping point. 
     According to one embodiment it is suggested to provide a central inlet or outlet located along a central axis of the filter candle, which is surrounded by two coaxial annular passages through which water can either be introduced or discharged. 
     In particular it is contemplated that the inlet is arranged between the first and the second outlet. 
     For example, the first outlet may be in the form of a central tube, radially adjoined by the inlet in the form of an annular passage, and the inlet in turn adjoined by the second outlet in the form of a further annular passage. 
     It has been found that in this way both the filter candle and the filter head can be designed to be particularly compact. 
     In one embodiment, the filter candle includes a mixing chamber in which the water that passed through the ion exchange material is mixed with the bypass flow. 
     The mixing chamber is therefore intended for providing the water for the second outlet. 
     According to one embodiment, a backflow preventer is arranged between the ion exchange material provided inside the filter candle and the mixing chamber. 
     The backflow preventer prevents bypass water from entering the water flow leading to the first outlet. 
     In this way it is ensured that only water that has been completely passed through the ion exchange material will reach the first outlet. 
     The backflow preventer may extend around a centrally arranged tube, in particular a downcomer, in particular in the form of a ring. 
     It is furthermore also possible to have a plurality of backflow preventers distributed around the centrally arranged tube. 
     For example, the backflow preventer can be plate-shaped and may comprise at least one cover which can only be opened by water that flows in one direction and is thus effective as a backflow preventer. 
     To this end, the at least one cover can be mounted resiliently and/or can be made of resilient material. 
     At least one filter layer is preferably arranged between the backflow preventer and the ion exchange material, which retains the ion exchange material. 
     The bypass water preferably passes through a filter layer. 
     It is in particular contemplated that the water from the aforementioned mixing chamber is passed through a filter layer. This filter layer may in particular include materials for removing germs and contaminants. More particularly, the filter layer may include activated carbon. 
     The provisioning of the bypass inside the filter candle has the advantage that in this way it is possible for the water directed through the bypass to also pass through a filter layer of the filter candle. This would not be possible if the bypass was provided through the filter head. 
     The dislosure also relates to a system for treating water, which comprises a filter candle. 
     More particularly, the disclosure relates to a system comprising a filter candle as described above. 
     The system comprises a filter head in which the filter candle is installed. 
     As stated above, the filter candle is filled with an ion exchange material. 
     The filter head has one inlet and at least two outlets. 
     The system is designed such that the water that can be extracted from a first outlet is softened to a greater extent than the water that can be extracted from a second outlet. 
     It is thus contemplated to divide the water directed through the filter candle into two partial flows, which will lead to two differently softened types of water due to a different dwell time in the ion exchange material and/or due to a different treatment. 
     The water provided at the second outlet is preferably produced using a bypass which serves to mix softened water with bypass water. 
     As described above, the bypass can be provided inside the filter candle. 
     According to another embodiment, the bypass may also be arranged in the filter head. 
     This embodiment has the advantage that the configuration of the filter candle can be simplified in this way. More particularly, the filter candle will require only one inlet and one outlet in this case. 
     However, a drawback of this embodiment is that the water directed through the bypass cannot be treated by the media provided inside the filter candle. 
     For the aforementioned first embodiment, the filter head may have a control element which is operable to actuate an actuator which engages in the filter candle and through which the flow ratio between the main flow and the bypass flow can be adjusted. 
     It is in particular contemplated to provide an actuator which can be displaced axially by means of a rotary control element and which is thus operable to open and close one or more openings of a passage of the filter candle so as to regulate the strength of the bypass flow. 
     The disclosure also relates to a filter head which is adapted for the system described above and which accordingly comprises one inlet and two outlets. 
     Otherwise, the filter head may comprise all the features described above in conjunction with the filter head. 
     In particular, the filter head may comprise a control element for setting the flow ratio between a main flow and a bypass flow, the control element extending around an outlet that extends centrally through and out of the control element. 
     According to this embodiment it is therefore contemplated that one outlet, in particular the first outlet through which water can be discharged that has not been mixed with water of the bypass flow is arranged centrally and preferably so as to be turnable with respect to the other connections. 
     In order to make the filter head compact and simple, this outlet extends out of the top of the filter head and is surrounded by the control element which may in particular be in the form of a rotary ring. 
     In a further embodiment, a bypass is provided inside the filter head. The bypass serves to mix water that is flowing out of the filter candle with inlet water. 
     This water, which will be less softened as a result, is fed to the second outlet, while water to which relatively little or no inlet water was added is fed to the first outlet. 
     In this embodiment, a filter candle with two outlets can be dispensed with. On the other hand, the water flowing through the bypass will not be treated at all. Therefore, this embodiment is particularly suitable for areas where the inlet water is already impeccable for human consumption. 
     A further aspect relates to a filter head. 
     More particularly, the disclosure relates to a filter head that has one or more of the features described above. 
     The filter head can, but does not need to have two outlets. Rather, the filter head may also have only one outlet. 
     The filter head is adapted for installing a filter candle therein, which has at least one inlet and at least one outlet, in particular by being screwed in. 
     The filter head comprises an outlet that is arranged coaxially to a central axis and is adapted to be turnable. 
     The central axis is in particular defined by the central axis of a thread for screwing in the filter candle. 
     The outlet is in particular in the form of an angled turnable tube. In this way, the outlet can easily be turned in the direction of the tapping point. 
     In one embodiment, a control element for a bypass extends around the outlet. 
     Hence, an outlet passage extends through the control element. 
     The control element may in particular be adapted so as to be turnable for setting a degree of softening. 
     The invention permits to provide a filter head with a compact design that can be connected easily and conveniently. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject-matter of the invention will now be explained in more detail by way of an exemplary embodiment with reference to the drawings of  FIGS.  1  through  13   . 
         FIG.  1    shows an exemplary embodiment of a system for treating water, which comprises a filter candle connected to a filter head. 
         FIG.  2    shows the system in a side elevational view. 
         FIG.  3    is a sectional view taken along line A-A as indicated in  FIG.  2   . 
         FIG.  4    is a detailed view of section A as indicated in  FIG.  3   . 
         FIG.  5    shows another side elevational view of the system. 
         FIG.  6    is a sectional view taken along line B-B as indicated in  FIG.  5   . 
         FIG.  7    is a detailed view of section B as indicated in  FIG.  6   . 
         FIG.  8    is a top plan view of the filter candle. 
         FIG.  9    is a bottom plan view of the filter head. 
         FIGS.  10  and  11    are longitudinal sectional views of the filter candle. 
         FIG.  12    is an axial sectional view of the filter head; and 
         FIG.  13    is a cross sectional view taken close to the inlet of the filter head. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    shows a perspective view of a system  1  for water treatment. 
     System  1  comprises a filter candle  100  that is installed in a filter head  200 . 
     Filter head  200  is used for on-site connection of the system  1  and has one inlet  201  for being connected to an on-site water pipe and two outlets  202 ,  203  from which water can be extracted. 
     In this view, the outlets  202 ,  203  are arranged on the side opposite to the inlet  201 , and outlet  202  is turnable by 360° so that it can be aligned in the direction of the tapping point. 
     Outlet  202  extends out of the top of the filter head  200  and is then angled. In this exemplary embodiment, the first outlet  202  is used to extract water which is softened to the maximum degree possible with the filter candle  100  and can be used like fully desalinated water, in particular for steam-generating devices such as steam cookers. 
     The second outlet  203  allows to extract partially softened water which can in particular be used for the preparation of beverages. 
     For example, the second outlet  203  can be connected to a machine for preparing hot beverages, such as a fully automatic coffee machine. 
     So it is possible to either extract softened water at the first outlet  202  or partially softened water at the second outlet  203 , or even to extract water at both outlets  202 ,  203  simultaneously. 
     The desired degree of hardness of the water dispensed at outlet  203  can be adjusted by means of a control element  204 . 
     Control element  204  is enabled by pressing the locking member  205  and can then be rotated to set the desired degree of hardness. 
     In this way, the softening is in particular adapted to the degree of hardness of the water at the respective location. Normally, the setting will then not be changed anymore. 
     A backflow preventer  215  arranged in the line of the first outlet  202  prevents softened water from being able to flow back. The second outlet also includes a backflow preventer (see  FIG.  7 ,  211   ). 
       FIG.  2    is a side elevational view of the system  1  looking at the outlets  202  and  203  (from the front). 
       FIG.  3    is a sectional view taken along line A-A as indicated in  FIG.  2   . 
     Filter candle  100  comprises a housing  101 . The head  102  of filter candle  100  has a thread  103  through which the filter candle is coupled to the filter head  200 . 
     The housing defines an interior  105  which is at least partially filled with a softening material, in particular with a weakly acidic ion exchange resin (not shown). 
     Water to be treated is directed from the filter head  200  into the housing  101  via a downcomer  104  and enters the interior  105  at the bottom of the housing through a lower inlet  108  which may include a filter layer. 
     The water then passes through the ion exchange material and is discharged as will be discussed in more detail below. 
       FIG.  4    is a detailed view of section A as indicated in  FIG.  3   , that is the area of the head  102  of filter candle  100  and of the filter head  200 . 
     Thread  103  of filter candle  100  is screwed into the thread  206  of filter head  200 . 
     Filter candle  100  has an inlet  107  through which water to be treated is introduced into the filter candle  100 . 
     The flow of inlet water is indicated by arrows on the right and the flow of the outlet water is indicated by arrows on the left. 
     The inlet  107  is defined by downcomer  104  through which water flows from the filter head  200  into the filter candle  100 . 
     The central passage  120  serves to discharge the water to the outlet  202 . 
     The inlet water is introduced into the downcomer  104  via passage  121  which is in the form of an annular passage, from where it is directed downwards and thus passes through the ion exchange material. 
     The central passage  120  which is defined by a tube  106  inside the filter candle  100  is arranged inside the downcomer  104 . Between tube  106  and downcomer  104  there is an annular passage through which water can flow downwards. 
     Filter candle  100  comprises a bypass in the form of at least one opening  109  in the downcomer  104 . 
     Part of the water can exit from the downcomer  104  laterally, through opening  109 , and is directed through passage  110  and into a mixing chamber  113  which is partially filled with at least one filter layer  112 . 
     The bypass  109  can be adjusted by actuating control element  204  to axially displace the actuator  207  through a threaded spindle. 
     The passage  120  which leads to the second outlet  202  also extends through the actuator  207 . 
     Moving the actuator  207  up and down, respectively, will change the open cross section of the opening  109  so that an adjustable bypass is provided in this way. 
     It will be appreciated that there may also be a plurality of openings provided instead of a single opening  109 , which are opened or closed one after the other. 
     From opening  109 , the bypass water flows through annular passage  110  and the bypass flow exits via passage outlet  111  and mixes with the water rising from the filter candle  100 . 
     The water flow from inlet  201  is directed via inlet  107  through downcomer  104  and into the interior  105 , where it rises again and passes through the ion exchange material. 
     In mixing chamber  113 , the rising water mixes with the bypass water. 
     Via passage  114  which leads to the second outlet  203  of filter head  200 , the water is discharged. Passage  114  is in the form of an annular passage and extends around the downcomer  104 . 
     The filter candle  100  thus has an inlet  107  which leads into an annular passage between tube  106  and downcomer  104 , and has an outlet also in the form of an annular passage  114 , which extends around the downcomer  104  and which leads to the second outlet  203  of the filter head  200  in the connected state. 
     The central axial passage  120  defines the outlet of filter candle  100  and leads to the first outlet  202  of the filter head  200 . 
     The water flowing through passage  120  is not mixed with the bypass flow, but rather enters the passage  120  via inlet  119  after having passed through the ion exchange material. 
     In order to prevent bypass water from flowing to the passage  120 , a backflow preventer  115  is arranged between the mixing chamber  113  and the inlet  119 . 
     In this exemplary embodiment, the backflow preventer  115  is in the form of an annular plate  116  that extends across the housing. 
     Plate  116  is provided with one or more resilient covers  117 . 
     More particularly, a single annular cover  117  can be used, or else a plurality of covers  117  distributed circumferentially so as to close the openings of plate  116 . 
     The one or more covers  117  are flexible and/or are resiliently mounted so as to be able to be deflected by water flowing into the mixing chamber  113 . 
     However, when water is extracted at the first outlet  202 , the one or more covers  117  will sit on the plate  116 , thereby preventing water from the mixing chamber  113  and thus bypass water from entering the inlet  119 . 
     In this exemplary embodiment, at least one filter layer  118  is arranged between backflow preventer  115  and the ion exchange material. This filter layer holds back the granulated ion exchange material. 
       FIG.  5    is another side elevational view of the water treatment system  1  consisting of filter candle  100  and filter head  200 . 
       FIG.  6    is a sectional view taken along line B-B as indicated in  FIG.  5   . 
       FIG.  7    is a detailed view of section B as indicated in  FIG.  6   . 
     In this view, the section is taken along the tubes which define the inlet  201  and the two outlets  202 ,  203 . 
     One backflow preventer  210  is arranged downstream of inlet  201 . 
     Another backflow preventer  211  is arranged upstream of outlet  203 . 
     In this view it can be seen that below the backflow preventer  115  of the filter candle water can flow into the passage  120  via inlet  119 , and this water will then reach the outlet  202  through passage  120  which extends through seal  208  and actuator  207 . 
     In the coupled state, seal  208  engages in tube  106  and thus connects the central outlet of filter candle  100  with the outlet  202  of filter head  200 . 
     As described above, this water is not mixed with bypass water and can therefore in particular be used for steam generating devices. 
     The inflowing water, on the other hand, flows through annular passage  121  along downcomer  104 . This annular passage  121  extends as far as to the inlet  119  into passage  120 , which extends laterally out of downcomer  104 . Only the downcomer  104  extends further downward. 
     Seal  209 , through which the passage  120  extends as well, seals off the inlet  107  to the outside. 
       FIG.  8    is a top plan view of the filter candle  100 . 
     Passage  120  is located in the center and is defined by tube  122  inside the filter candle  100  and defines the first outlet of the filter candle  100 . 
     In the connected state, the tube  122  engages around seal  208  which can be seen in particular in the bottom plan view of the filter head  200  according to  FIG.  9   , through which the passage  120  passes into filter head  200 . 
     Annular passage  121  which is defined by downcomer  104  extends around the tube  122 . 
     The downcomer  104  extends further upward than the inner tube  122 . Thus, the bypass  109  can be provided in the downcomer  104  above the inner tube  122 . 
     Annular passage  114 , in turn, extends around the downcomer  104  and is defined by the outer tube  123  which extends around the downcomer. This annular passage  114  serves as the second outlet of the filter candle  100 . 
     The filter head  200  has a complementary design and comprises an inner annular passage  212  through which water flows into the downcomer  104 , and an outer annular passage  213  through which water flows to the second outlet  203 . 
       FIG.  10    is an axial sectional view of the head  102  of filter candle  100 . 
     Tube  122  is accommodated inside and spaced apart from the downcomer  104 , so that the actuator  207  of the filter head  200  can engage in the downcomer in the upper section of the downcomer  104 . 
     The annular passage  114  of the second outlet extends around the downcomer  104 . 
       FIG.  11    is a sectional view with the sectional plane offset parallel to that of  FIG.  10   . 
     It can be seen that the downcomer  104  is double-walled at least in sections thereof. A gap is defined between the inner wall  104   a  and the outer wall  104   b  and defines a passage  110  (see  FIG.  4   ) through which bypass water can flow from the opening  109  of inner wall  104   a  and into the mixing chamber  113 . 
     The cross section of opening  109  can be varied through actuator  207 . 
       FIG.  12    is an axial sectional view and  FIG.  13    is a cross-sectional view of the filter head  200  in the area of the inlet  201  and second outlet  203 . 
     The inlet  201  leads into a seat  214  for the downcomer  104  which comprises the inlet  107  of the filter candle  100 . 
     As shown in  FIG.  13   , the outer passage  213  of the head  200  leads to the second outlet  203 . 
     The invention allowed to provide a compact system for water treatment, which comprises an outlet at which water is provided in particular for beverages, and in addition thereto a further outlet at which more strongly softened water can be extracted, which can be used for steam generating devices, for example. 
     LIST OF REFERENCE NUMERALS 
       1  Water treatment system 
       100  Filter candle 
       101  Housing 
       102  Head 
       103  Thread 
       104  Downcomer 
       104   a  Inner wall of downcomer 
       104   b  Outer wall of downcomer 
       105  Interior 
       106  Tube 
       107  Filter candle inlet 
       108  Lower inlet 
       109  Opening/bypass 
       110  Passage/annular passage 
       111  Passage outlet 
       112  Filter layer 
       113  Mixing chamber 
       114  Passage/annular passage 
       115  Backflow preventer 
       116  Plate 
       117  Cover 
       118  Filter layer 
       119  Inlet 
       120  Passage 
       121  Passage/annular passage 
       122  Tube 
       123  Outer tube 
       200  Filter head 
       201  Inlet 
       202  First outlet 
       203  Second outlet 
       204  Control element 
       205  Safety element 
       206  Thread 
       207  Actuator 
       208  Seal 
       209  Seal 
       210  Backflow preventer inlet 
       211  Backflow preventer second outlet 
       212  Annular passage 
       213  Annular passage/passage 
       214  Seat 
       215  Backflow preventer first outlet