EP3435829B1

EP3435829B1 - Granule valve arrangement for a dishwashing apparatus

Info

Publication number: EP3435829B1
Application number: EP17716323.5A
Authority: EP
Inventors: Mats JÖNSSON; Amir JASAREVIC; Per Walter
Original assignee: Granuldisk AB
Current assignee: Nordisk Clean Solutions AB
Priority date: 2016-03-30
Filing date: 2017-03-30
Publication date: 2023-06-21
Anticipated expiration: 2037-03-30
Also published as: SE540513C2; EP3435829A1; SE1650414A1; WO2017171620A1

Description

Technical Field

The present disclosure relates to a granule valve arrangement for a dishwashing apparatus, and more particularly to a granule valve arrangement comprising a removable granule basket arranged on a granule valve for a granule dishwashing apparatus, a dishwashing apparatus and method for operating the same.

Background

Dishwashers for heavily soiled articles to be washed, for example dishwashers for pots and pans, use liquid that is sprayed under high pressure towards the articles to be washed. In order to increase the field of application of the dishwashers, liquid may be circulated alternatively with and without granules. Thereby, the dishwashers may be used for washing both heavily soiled articles with granules and more sensitive ware, such as crockery, cutlery and glasses, without the granules.
After the articles have been washed, a separation of granules from liquid is necessary to remove the granules from the dishwasher for facilitating cleaning of the granules as well as cleaning of the interior of the dishwasher. The granules may need to be removed when the dishwasher is to be used without granules.
Prior art dishwashers separate granules from liquid in various ways. A separate granule collector may be put into the dishwasher for collecting granules during a separation cycle. A problem with the prior art methods and granule collectors is that granules remain in the tank even at the end of the separation cycle.
US4374443 describes cleaning machine for blasting the goods to be cleaned. Inside a liquid container there is provided a liquid-permeable compartment or cassette providing a magazine for the granules and connected to a bottom outlet in a treatment chamber wherein the blasting shall take place. The compartment or cassette is connected by a valve-controlled opening to the suction side of a pump for sucking-in liquid from the liquid container via the cassette, while carrying granules therefrom and for supplying the liquid containing granules to the treatment chamber from which the granules are again supplied to the cassette through the bottom outlet.
US2002031989 describes a granule dishwashing apparatus with removable granule collectors and method of use. The dishwashing apparatus consists primarily of a treatment chamber, a tank, one or more granule collectors and one or more pumping devices. Soiled articles are placed in the treatment chamber to be washed with a mixture consisting of liquid and granules that is sprayed at the articles under high pressure. The mixture falls toward the tank after impacting the articles, passing through the granule collector(s). Liquid is separated from the mixture at some point using the granule collector(s) so that the articles can be rinsed. At any point following a cleaning cycle, the granule collector(s) can be removed to add more granules and to enable cleaning of the apparatus. In a multiple collector system, the granule collectors are connected to actuators so that the collectors can be placed in a release mode or a collect mode depending on the function desired.
However, the shape and construction of prior art granule collectors and the position of the granule collector in the tank prevent an efficient addition of granules when desired as well as collection of granules when they are to be removed from the tank. A normal separation period requires circulation of the total tank volume many times for colleting most of the granules. Granules may easily fall into the conduit or the tank when the granule collector is removed from the tank.

Summary

It is an object of the teachings of this application to obviate at least some of the above disadvantages and to provide an improved granule valve arrangement for a granule dishwashing apparatus, providing an efficient and fast addition of granules when desired as well as a fast collection of granules when they are to be removed from the dishwashing apparatus.
According to a first aspect, this is achieved by a granule valve arrangement for a granule dishwashing apparatus, comprising a removable granule basket removably arranged on a granule valve, said granule valve is arranged to be altered between a closed position, wherein a valve head covers an aperture in the bottom of the granule basket for collecting granules in the granule basket, and an open position, wherein the valve head is moved upwards so that granules can pass from the granule basket through the aperture in the bottom of the granule basket into the granule valve.
In some embodiments, the removable granule basket is a cylindrical basket, open in the top end and perforated by recesses or holes around the basket, the recesses or holes are sufficiently wide to allow the passage of liquid but small enough to prevent the passage of granules.
In some embodiments, the granule basket comprises a larger cylindrical upper portion and a smaller cylindrical lower portion assembled together, the larger cylinder upper portion is both higher and has a larger diameter than the lower smaller cylinder portion, the basket is provided with two pins or wire bows projecting from opposite sides of an envelope surface of the smaller cylindrical lower portion for connecting the granule basket to the granule valve.
In some embodiments, the granule basket is provided with a handle for insertion and removal of the granule basket by hand from the dishwasher.
In some embodiments, the granule valve comprises an upper perforated open ended cylindrical sleeve arranged on a branch conduit, the cylindrical sleeve has two recesses partly around portions of the cylindrical sleeve for receiving the pins of the granule basket for connection of the granule valve to the granule basket.
In some embodiments, the granule valve comprises a wire stand arranged on the branch conduit, wherein the wire stand comprises an upper part corresponding to the larger cylindrical upper portion and a lower part corresponding to the smaller cylindrical lower portion of the basket, opposite bent portions of at least one circular wire of the wire stand for receiving the wire bows of the granule basket for connection of the granule valve to the granule basket.
In some embodiments, a perforated filter plate or mesh is arranged on a top inlet of or within the branch conduit, wherein the perforations are large enough to let both liquid and granules to flow in to the branch conduit but preventing food scraps and/or cutlery to limit or stop up the flow through the branch conduit.
In some embodiments, the granule valve comprises a vertical valve push rod, which extends from the bottom of and through the branch conduit and is provided with a valve cone at the top end thereof forming a valve plunger.
In some embodiments, the valve head has a conical cavity arranged on top of the valve cone and rests on a chamfered edge around an aperture in a bottom end of the larger cylindrical upper portion of the granule basket, wherein the valve head has a shape large enough to cover the aperture, in a closed position.
In some embodiments, the valve head has a conical cavity arranged on top of the valve cone and a cylindrical lower flange of the valve head rests around an aperture on a bottom end of the upper portion of the granule basket, in a closed position.
In some embodiments, the bottom end is perforated by recesses or holes sufficiently wide to allow the passage of the liquid flow but small enough to prevent the passage of granules.
In some embodiments, the granule valve arrangement, comprises a valve lifter arrangement including an electric motor operatively connected to a hinged lever arrangement adapted to generate an upward and a downward movement of the valve push rod connected to the hinged lever arrangement, wherein the valve head is movable between the closed position for collecting granules in the granule basket and the open position so that granules can pass through the bottom of the granule basket.
According to a second aspect, a granule dishwashing apparatus is provided, comprising a granule valve arrangement.
In some embodiments, the granule dishwashing apparatus comprises a dishwashing chamber, a washing tank and a rinse tank located below the dishwashing chamber, a conduit system connecting the tanks to the dishwashing chamber, and a sink above the washing tank, wherein the removable granule basket is removably arranged in a hole in the bottom of the sink, the circular top end of the granule basket is located at the same level as the bottom of the sink, and the hole in the bottom of the sink and the circular top end have corresponding diameters.
In some embodiments, the granule dishwashing apparatus comprises a rotatable spray arm, comprising an elongated surface member and an elongated casing on both sides of a center section, the surface member and the casing are assembled together forming an inside chamber of the spray arm, wherein the inside chamber is divided in separate elongated washing channels provided on each side of the center section, said washing channels are connected to a dishwashing inlet arranged to guide dishwashing liquid into the washing channels towards spray nozzles at the end of each washing channel.
In some embodiments, the granule dishwashing apparatus comprises a sensor arranged in the washing tank to detect whether the granule basket is attached to the granule valve in the dishwashing apparatus.
In some embodiments of the granule dishwashing apparatus, the sensor is operatively connected to the circuitry of the electrical cabinet and configured to generate a sensor signal indicating whether the granule basket is located and available for providing granules to the liquid depending on the washing program in operation.
In some embodiments of the granule dishwashing apparatus, the sensor is a magnetic or magneto-optical sensor.
According to a third aspect, a method for operating a dishwashing apparatus is provided, comprising:

initiating the liquid pump for providing liquid with low liquid pressure;
detecting a ware holder adapted for coarse washing in the chamber, and that the granule basket is attached to the granule valve;
controlling the granule valve to open for adding granules to the liquid;
dishwashing with liquid and granules;
controlling the granule valve to close for collecting the granules in the granule basket; and
rinsing the ware holder.

An efficient and fast addition of granules when desired as well as a fast collection of granules when they are to be removed from the dishwashing apparatus are provided.
Other aspects and features of the invention and its embodiments are further explained in the detailed description and the drawings, and are defined by the appended claims.
It should be emphasized that the term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps, or components, but does not preclude the presence or addition of one or more other features, integers, steps, components, or groups thereof.

Brief Description of the Drawings

Further objects, features and advantages will appear from the following detailed description of embodiments, with reference being made to the accompanying drawings, in which:

FIG. 1 is a perspective view of a dishwashing apparatus according to an embodiment;
FIG. 2 is a perspective view of a rotatable spray arm with outlets according to an embodiment for a dishwashing apparatus as shown in FIG. 1;
FIG. 3 is a perspective view of a rotatable spray arm as shown in FIG. 1 with an inlet connection;
FIG. 4 is a perspective view of one part of the rotatable spray arm as shown in FIG 2A with rinsing and washing channels;
FIG. 5 is a locally enlarged perspective view of the rotatable spray arm as shown in FIG. 4;
FIG. 6 is a perspective view of a rotatable spray arm with outlets according to an embodiment;
FIG. 7 is a perspective view of a rotatable spray arm as shown in FIG. 6 with an inlet connection;
FIG. 8 is a perspective cross-sectional view of a portion of the rotatable spray arm in FIG. 7;
FIG. 9 is a cross-sectional view of the rotatable spray arm in FIG. 6;
FIG. 10 is a bottom view of a surface member of the rotatable spray arm as shown in FIG. 6;
FIG. 11 is a perspective view of a granule container;
FIG. 12 is a perspective view of a granule valve;
FIG. 13 is a perspective view of the granule container in FIG. 11 attached to a granule valve in FIG. 12;
FIG. 11A is a perspective view of a granule container;
FIG. 12A is a perspective view of a granule valve;
FIG. 13A is a perspective view of the granule container in FIG. 11A attached to a granule valve in FIG. 12A;
FIG. 14 is a cross-sectional view of a portion of the granule container as shown in FIG. 12 with a closed granule valve;
FIG. 15 is a cross-sectional view of the granule container as shown in FIG. 12 with an open granule valve;
FIG. 15A is a cross-sectional view of the granule container as shown in FIG. 12A with a closed granule valve;
FIG. 16 is a perspective view of a tray for loading articles; and
FIG. 17 is a flowchart of a dishwashing method.

Detailed Description

Embodiments of the invention will be described with reference to FIGs. 1-17, which illustrate schematically an example arrangement to some embodiments. The same reference signs are used for corresponding features in different figures. The terminology used in the detailed description and drawings of the embodiments is not intended to be limiting.
The following description describes embodiments applicable to the field of dishwashing apparatuses for equipment surface treatment, such as dishwashers, including but not limited to dishwashers for small, medium, and large sized commercial kitchens, such as pot washers. The dishwashing apparatuses may be, but is not limited to, dishwashers for heavily soiled articles to be washed, for example dishwashers for pots and pans or other coarse articles to be washed. However, it will be appreciated that the disclosure is not limited to this application but may be applied to many other technical fields wherein a tray, basket or the like holding articles, including pots, pans, cauldrons, underwater equipment, such as a scuba diving equipment, working clothes, different kinds of tools or other industrial equipment etc, to be washed.
FIG. 1 shows an embodiment of a dishwasher 100 for heavily soiled articles to be washed, for example pots, pans, ovenware, canteens etc., wherein the dishwasher may be arranged to add granules with liquid, including but not limited to water, or water and detergent, or any other suitable liquid for dishwashing that is sprayed under pressure towards the articles to be washed. In some embodiments the dishwasher may be arranged to circulate liquid alternatively with and without granules and/or with and without detergent. Thereby, the dishwashers may be used for washing more sensitive ware, such as crockery, cutlery and glasses, without the granules. The granules may be made of, but is not limited to, plastic material.
Referring to FIG. 1, the granule dishwasher 100 according to some embodiments comprises a stand 101, a dishwashing chamber 102, a washing tank 103a for washing liquid and a rinse tank 103b with a pump for rinsing liquid located below the dishwashing chamber and arranged on the stand, and a conduit system 104, comprising a washing liquid conduit system 104a and a rinse liquid conduit system 104b. The washing liquid conduit system connects the washing tank 103a to the dishwashing chamber 102 and the rinsing liquid conduit system connects the rinse tank 103b to the dishwashing chamber 102. A back wall 105 of the stand, a sink 106 and a hood 107 may form the chamber 102. The hood 107 is movably arranged to the back wall 105 of the stand. The hood 107 may be moved between a closed position as shown in FIG. 1 when the dishwasher is ready for operation, and an open position, in which dishes, preferably on a washing rack or ware holder, may be put into or removed from the chamber. The hood 107 may be moved by means of handles 108 arranged on the exterior of the hood.
Further, the dishwasher 100 comprises a liquid or water pump 109 arranged in the lower part of the stand 101, which can operate at different speeds, leading to different liquid pressures and flow of liquid and dishwater with an without granules through an upper rotatable spray arm 110 arranged in the upper part of the chamber 102 and a lower rotatable spray arm 111 arranged in the lower part inside the chamber 102 and connected to the washing liquid conduit system 104a.
The pump of the rinse tank 103b may be configured to operate at different speeds, leading to different liquid pressures and flow of liquid through the upper rotatable spray arm 110 and the lower rotatable spray arm 111 being connected to the rinsec liquid conduit system 104b.
The rinse liquid conduit system 104b may have a rinsing pipe 112 for providing rinsing liquid, i.e fresh water, circulation water, or any other suitable liquid, with or without rinsing agent, to the upper spray arm 110 and a separate dishwashing pipe 113 for providing dishwater to the upper spray arm 110. A corresponding arrangement with rinsing pipe and dishwashing pipe is provided for the lower spray arm 111. A low speed is used for washing up crockery, cutlery and glasses and a higher speed is used for pot washing. The speed of the liquid pump and the resulting liquid pressure should be adjusted to the specific dishwasher and the type of glassware or pots etc that are going to be washed up. Moreover, an electric cabinet 114 is arranged in the lower part of the stand 101 configured for main connection and power supply of the liquid pump 109, heaters in the washing tank and the rinse tank, the pump of the rinse tank, the pump of the rinse tank, and a draining pump 115. The electric cabinet 114 may contain circuitry and/or a program-control device configured to run one or more different washing programs for operating the dishwasher in response to user input via a user interface, such as a control panel 116, arranged on and accessible from the exterior of the dishwasher and operatively connected to the circuitry.
The liquid pump 109 and draining pump 115 are connected to the washing tank 103a through the washing liquid conduit system 104a. As mentioned above, the liquid pump 109 may be configured to operate at different speeds, leading to different water pressures and flows. A low speed is used for washing up crockery, cutlery and glasses and a higher speed is used for pot washing, with or without granules. The granules may be made of, but is not limited to, different plastic material preferably soft enough not to harm pans or the wash system, but hard enough to remove food from pots and pans. The lower part of the dishwasher may also comprise a removable granule container or basket 117, where the granules may be collected, separated from the liquid and removed from the dishwasher. This granule basket 117 may be provided with a granule valve 118 together forming a granule valve arrangement, for controlling the addition/collection of granules to/from the liquid in response to the washing program being run.
The speed of the liquid pump and the resulting liquid pressure through the spray arms 110, 111 may be adjusted to the specific machine and what type of glassware or pots that are going to be cleaned. The liquid pump 109 can also be driven by a standard electric motor, which is controlled by a speed regulator, such as a frequency changer or a variable-frequency drive. This gives more flexibility and several different speeds and liquid flows with and without granules can be provided.
FIG. 2 shows the rotatable spray arm 110, 111 according to an embodiment for a dishwashing apparatus as shown in FIG. 1. The upper and lower rotatable spray arms 110, 111 may have identical features and may be connected to the conduit system 104 in the same way and provide the same functional characteristics in operation. However, for the sake of simplicity only one of the rotatable spray arms 110, 111 will be described in detail herein. The spray arm 110 may comprise an elongated surface member 200 and an opposite elongated casing 202 on both sides of a center section 203. The elongated surface member 200 and the elongated casing 202 are assembled together, for example but not limited to a snap connection, forming an inside chamber of the spray arm 110 with number of channels for rinsing and dishwashing liquid. The elongated surface member 200 may be provided with a number of spray outlets, including spray jets or holes 204 for rinsing liquid, which are distributed along a first edge 205a of the surface member 200 on one side of the center section 203 and along a corresponding second edge 206a of the surface member 200 on the other side of the center section 203, which is illustrated in FIG 2. The elongated surface member 200 and casing 202 may be formed by, but not limited to, injection-molded plastic material.
The spray jets 204 are inclined at any angle α (see FIG. 9) in the range of: 0< α <90, preferably but not limited to about 20°, in relation to the rotational axis Z (FIG. 1) of the spray arm when it is arranged in the dishwasher" from the inside chamber towards the edge along which the spray jets are disposed. Thereby, the spray arm 110 will be rotating in dependence on the amount and pressure of the rinsing liquid being pumped through the rinse liquid conduit system 104b into the spray arm 110 further through the spray jets 204.
The elongated surface member 200 may be provided with additional spray outlets, including a number of spray nozzles 212a-f for dishwashing liquid, three of which are distributed along a third edge 205b of the surface member 200 on one side of the center section 203 and the other three along a corresponding fourth edge 206b of the surface member 200 on the other side of the center section 203, which is illustrated in FIG 2. The spray nozzles 212a-f are disposed at any suitable angle β in the range of 0< β<90°, preferably but not limited to about 20°, in relation to the length of the spray arm 110. In operation, dishwashing liquid flowing through the spray arm and out from the angled nozzles creates a force making the spray arm to rotate around its center section 203. Hence, the spray arm 110 will be rotating in dependence on the amount and pressure of the dishwashing liquid being pumped through the conduit system 104 into the spray arm 110 further through the dishwashing channels (described below) and the spray nozzles 212a-f.
As shown in FIG. 2, the spray nozzles 212a-c may be located at different individual distances from the center section than the spray nozzles 212d-f, thereby achieving good flow coverage, preferably overlapping, in the dishwashing chamber 104 for an improved dishwashing result.
FIG. 3 shows the rotatable spray arm 110 as shown in FIG. 1 with an inlet connection 203a at the centre section 203 configured for rotatable connection to the conduit system 104, 104a, 104b. The connection 203a has a rinsing inlet 220 for guiding rinsing water into rinsing channels 230, 231 and a dishwater inlet 222 for guiding dishwater/liquid with or without granules into washing channels 232-234 and 235-237. Although, the rinsing inlet 220 and the dishwater inlet 222 are separate, the rinsing inlet 220 may have a filter 225 for preventing granules in the dishwater to pass into the rinsing channel of the spray arm 110, which otherwise may lead to clogged spray jets 204.
FIG. 4 illustrates the elongated casing 202 forming one part of the rotatable spray arm 110, which is provided with at least one rinsing channel 230, 231 in connection with the rinsing inlet 220 for rinsing water/liquid and the washing channels 232-234 and 235-237 in connection with the dishwater inlet 222 for dishwater/ dishwashing liquid with or without granules. In this embodiment, one rinsing channel 230, 231 is arranged on each side of the center section 203 providing an even distribution of rinsing water through the individual spray jets 204 in the surface 200, shown in FIG. 2. Individual washing channels 232-234 and 235-237 are provided on each side of the center section 203 in this embodiment, whereby almost the same pressure and flow of dishwater is provided in each spray nozzle 212a-f. In case of granules being used in the dishwater, they will be evenly distributed in the washing channels and the nozzles 212 a-f. In this embodiment the washing channels may have, but is not limited to, in cross section a shape corresponding substantially to a snip same side corner, snip corner, round same side corner, or round corner rectangle or similar shape. The geometry of the channels, i.e the shape in cross-section and in addition the relation between width and height of the channels, will produce an advantageous flow and prevent granule traps or clogging channels.
The spray arm is, however, not limited to one rinsing channel and three dishwashing channels on each side of the center section. The spray arm may have 1, 2, 3 or more rinsing channels and/or 2, 3, 4 or more individual washing channels on each side of the center connection in other embodiments of the spray arm.
FIG. 5 shows a locally enlarged view of end portions 242-244 of the washing channels 232-234. It should be understood that the features and advantages described herein with reference to the washing channels 232-234 are applicable to the other washing channels 235-237 and their end portions.
In this embodiment each end portion 242-244 has an inclined, curved or rounded shape 252-254, thereby guiding the dishwater with or without granules from the washing channels 232-234 towards the nozzles. Moreover, the shape of the channels may be narrowing from the center section 203 towards the nozzles, which may be provided by a continuous variation of the radius of the snip/rounded corners along the channels and shape of the end portions may be narrowing or angled in line with the nozzles. Dishwater /liquid with and without granules are accelerated by means of the particular shape of the end portion, thereby causing self-cleaning of the channel due to "no dead end" and preventing clogging of granules and/or food particles at the end portion of the channel and the connecting nozzles 212a-f (as shown in FIG 2).
The shape of the end portions of the washing channels and the angled nozzles may even create a combined effect to increase the moving and rotational force by means of flowing dishwashing liquid for rotating the spray arm. Hence, the spray arm 110 will be rotating in dependence on the amount and pressure of the dishwashing liquid being pumped through the conduit system 104 into the spray arm 110 further through the dishwashing channels 232-237 and the spray nozzles 212a-f.
FIG. 6 is a perspective view of a portion of a rotatable spray arm 348 according to another embodiment for a dishwashing apparatus as shown in FIG. 1. The spray arm 348 may comprise an elongated surface member 300 and an opposite elongated casing 302 on both sides of a center section 303. The elongated surface member 300 and the elongated casing 302 are assembled together, for example but not limited to screw fastening 350, forming an inside chamber of the spray arm 348 with a number of channels for rinsing water/liquid and washing channels for dishwater/dishwashing liquid with or without granules. The elongated surface 300 may be provided with a number of spray jets or holes 304 for rinsing liquid, which are distributed along a first edge 305a of the surface member 300 on one side of the center section 303 and along an opposite second edge 306a of the surface member 300 on the other side of the center section 303, which is illustrated in FIG 6. The elongated surface member 300 and casing 302 may be formed by, but not limited to, injection-molded plastic material.
The elongated surface member 300 may be provided with a number of spray nozzles for dishwashing liquid, which are distributed on both sides of the center section 303. In this embodiment, three spray nozzles 312a-c are distributed along one side of the center section 303 and another three spray nozzles 312 d-f along the other side of the center section 303. In addition, still another nozzle 312g is arranged at the center section 303.
As shown in FIG. 6, the spray nozzles 312 a-g may be located at different individual distances from the center section, thereby achieving distributed spray coverage in the dishwashing chamber 102 for an improved dishwashing result.
FIG. 7 shows the rotatable spray arm 348 as shown in FIG. 6 with an inlet connection 303a at the centre section 303 configured for rotatable connection to the conduit system 104, 104a, 104b. The connection 303a has a rinsing inlet 320 for guiding rinsing water into rinsing channels 330, 331 and a dishwater inlet 322 for guiding dishwater with or without granules into washing channels 332-334 and 335-337. Although, the rinsing inlet 320 and the dishwater inlet 322 are separate, the rinsing inlet 320 may have a filter 325 for preventing granules in the dishwater to pass into the rinsing channel of the spray arm 348, which otherwise may lead to clogged spray jets 304.
Moreover, the shape of the channels may be narrowing from the center section towards the nozzle and shape of the end portions may be narrowing or angled in line with the nozzles. Dishwater with and without granules are accelerated by means of the particular shape of the end portion, thereby causing self-cleaning of the channel due to "no dead end" and preventing clogging of granules and/or food particles at the end portion of the channel and the connecting nozzles.
FIG. 8 shows an enlarged cross-sectional portion of the rotatable spray arm 348 in FIG. 7. In this embodiment the washing channels 336, 337 may have, but is not limited to, in cross section a shape corresponding substantially to a snip same side corner, snip corner, round same side corner, or round corner rectangle or similar shape. Preferably, all washing channels 332-337 may have the same shape in cross section. The shape and geometry of the channels will produce an advantageous flow and prevent granule traps or clogging of granules and/or food particles at the end portion channels.
In this embodiment, the rinsing channel 331 may have a rectangular shape in cross section. Moreover, the spray jets 304 are inclined at any angle α, preferably but not limited to about 20° in relation to the rotational axis Z, i.e from the inside chamber towards the edge along which the spray jets are disposed. Thereby, the spray arm 348 will be rotating in dependence on the amount and pressure of the rinsing liquid being pumped through the rinse liquid conduit system 104b into the spray arm 348 further through the spray jets 304.
Reference is made to FIG. 9 which is an enlarged cross-sectional view of the spray arm in FIG. 6. The spray nozzles 312 (a-f) are disposed at any suitable angle in the range of: 0< β<90, preferably but not limited to about 20° in relation to the length of the spray arm 348. The angled nozzles create a moving and rotational force by means dishwashing liquid sprayed out from the nozzles as described above. In this embodiment, the spray nozzles 312 are projecting from the surface 300 as short pipe ends having cross sections in the shape of an elongated rectangle with convex long side walls 315, 316. The convex long side walls 315,316 are provided with an elongated concave cut-in portion 317 while two opposite short side walls 318,319 are rectangular as illustrated in FIG. 9. The side walls 315, 316, 318, 319 may have a curved top edge 327.
In another embodiment, the nozzles may have in cross section a shape corresponding substantially to an elongated rectangle of which the short sides of the rectangle are rounded or semicircular.
The particular shape of the nozzles described herein may provide an advantageous spray pattern from the nozzles and self cleaning of the nozzles making an improved dishwashing effect.
FIG. 10 shows a reverse side of the elongated surface member 300 forming an inner side of the spray arm 348, arranged with the rinsing spray jets 304 and holes 322a-g connected to and angled in line with the dishwashing nozzles 312a-g as shown in FIG. 6. In this embodiment, the holes 322a-g may have, but is not limited to, in cross section a shape corresponding substantially to an elongated rectangle of which the short sides of the rectangle are rounded or semicircular.
An O-ring sealing 325 or similar sealing made of, but not limited to, rubber, is advantageously arranged around the rinsing channel(s) 330, 331 forming a water tight sealing for preventing leakage of rinsing liquid and dishwashing liquid with and without granules between the rinsing channel(s) 330, 331 and the dishwashing channels 332-337. The O-ring is preferably arranged in a recessed flange 326 on the inside of the surface member 330 forming a tight sealing between the surface member 300 and the casing 302 of the assembled spray arm 348, as shown in FIG. 7.
The dishwasher may be provided with either an upper spray arm or a lower spray arm or both. The upper spray arm and the lower spray arm may be any combination of the embodiments of the spray arms 110, 111, 348, i.e two identical spray arms of the same embodiment or a combination of two different embodiments. In some embodiments, the dishwasher 100 is arranged to supply liquid to the upper spray arm 110 for washing, and liquid with or without granules to the lower spray arm 111 for washing. Both spray arms 110, 111 may be supplied with rinsing liquid during the rinsing phase of the washing program.
FIG. 11 shows an embodiment of the removable granule container or basket 117 in which granules may be collected and separated from the liquid. In this embodiment, the granule basket 117 may be a cylindrical basket, open in the top end 119 and perforated by recesses or holes 120 around the basket. The recesses or holes may be sufficiently wide to allow the passage of liquid but small enough to prevent the passage of granules. The granule basket 117, which is preferably made of any suitable metal or plastic material, may comprise a larger cylindrical upper portion 121 and a smaller cylindrical lower portion 122 assembled together. The larger cylindrical upper portion is both higher and has a larger diameter than the smaller cylindrical lower portion. In this embodiment, the basket is provided with two pins 123 (one shown in FIG. 11) projecting from opposite sides of the envelope surface of the smaller cylindrical lower portion 122. The basket may be provided with a handle 124 for easy insertion and removal of the granule basket 117 by hand from the dishwasher 100.
The granule valve 118, which is arranged in the dishwasher as shown in FIG. 1, is illustrated in further detail in FIG 12. In this embodiment the granule valve may comprise an upper perforated open ended cylindrical sleeve 125 arranged on a branch conduit 126, which may have a perforated filter plate or mesh 127 arranged either on a top inlet of the conduit 126 or within the conduit. The perforations are large enough to let both liquid and granules to flow in to the branch conduit 126 but preventing food scraps and cutlery to limit or stop up the flow through the branch conduit. A pipe joint 128 is provided in the lower part of the branch conduit for connection to the conduit system 104, wherein the flow of liquid, with or without granules, may be drawn by means of the liquid pump 109 when the dishwasher is in an operating mode. Moreover, a draining pipe 129 is provided in the lower part of the branch conduit for connection to the draining pump 115.
The cylindrical sleeve 125 may have two L shaped recesses 130, 131 partly around portions of the cylindrical sleeve 125 for receiving the pins 123 of the granule basket 117 for connection of the granule valve 118 to the granule basket 117. The sleeve 125 may be assembled to the branch conduit 126 by means of a knurled nut 132 for easy disassembling/assembling in case of cleaning of the granule valve.
The granule valve 118 further comprises a valve push rod 133, which extends from the bottom of the branch conduit 126 through the filter plate 127 and the cylindrical sleeve 125. The valve push rod 133 is provided with a valve cone 134 at the top end thereof forming a valve plunger, which is arranged to open and close the granule valve arrangement, as will be described below.
As shown in FIG. 13 the granule basket 117 is removably arranged on the granule valve 118 forming a granule valve arrangement, wherein the pins 123 of the granule basket have been inserted in the corresponding recesses 130, 131 of the cylindrical sleeve 125 of the granule valve 118 by turning the granule basked until the pins 123 reach the end of the recesses 130, 131. A sensor 135, such as a magnetic or magneto-optical sensor, may be arranged in the washing tank 103a in order to detect whether the granule basket is attached to the granule valve 118. The sensor 135 is operatively connected to the circuitry of the electrical cabinet 114 and configured to generate a sensor signal indicating whether the granule basket 117 is located and available for providing granules to the liquid depending on the washing program in operation.
FIG 14 illustrates a portion of the granule basket 117 attached to the granule valve 118 forming the granule valve arrangement. In this embodiment, a massive "puck" with a conical cavity is arranged as a valve head 136 on top of the valve cone 134. In a closed position as is shown in FIG 14, the valve head 136 rests on an edge 137, preferably chamfered, around an aperture 138 in a bottom end 139 of the upper portion 121 of the granule basket 117. The aperture 138 may preferably have a circular shape or any other suitable shape, such as oval or rectangular etc. The valve head 136 has a corresponding shape, and large enough to cover the aperture in a closed position. In some embodiments, the bottom end 139 may be perforated by recesses or holes 140 similar to the recesses or holes 120 in the envelope of the cylindrical granule basket 117. The recesses or holes 140 may be sufficiently wide to allow the passage of the liquid flow but small enough to prevent the passage of granules. A liquid flow through the recesses 140 may advantageously prevent granules from getting caught between the valve head 136 and the chamfered edge 137 when the granule valve 118 is moved to a closed position by a downward movement of the valve push rod 133.
FIG. 15 illustrates the granule valve arrangement including the removable granule basket 117 assembled with the granule valve 118 inserted in the dishwasher in an operative position. The removable granule basket 117 is inserted in the dishwasher, and arranged in a hole 119' in the bottom of the sink 106, wherein the circular top end 119 of the granule basket is located at the same level as the bottom of the sink. The hole 119' in the bottom of the sink and the circular top end 119 have corresponding diameters, so that granules cannot pass there between into the washing tank 103a. Preferably, the circular top end 119 may have a flange that may rest on the edge of the hole 119', when the granule basket is inserted into the dishwasher.
In this embodiment, an upward movement of the valve push rod 133 is generated by a valve lifter arrangement comprising an electric motor 141, which is operatively connected to and controlled by the circuitry and the program control device of the electric cabinet 114. A hinged lever arrangement 142 that may be moved backward and forward (corresponding to a left direction and a right direction in FIG. 15) is operatively connected an controlled by the electric motor 141. A backward movement of the hinged lever arrangement 142 causes an upward movement of the valve push rod 133, thereby moving the valve head 136 in to the position as shown in FIG. 15, i.e in an open position of the granule valve arrangement. A forward movement of the hinged lever arrangement 142 causes a downward movement of the valve push rod 133, thereby moving the valve head 136 in to a position as shown in FIG. 14, i.e the closed position of the granule valve arrangement. Thereby, an efficient and fast addition of granules is provided by a fast opening of the granule valve when granules are desired as well as an efficient collection of granules is provided by a fast closing of the granule valve when the granules are to be removed from the dishwashing apparatus.
FIG. 11A shows an embodiment of a removable granule container or basket 117a in which granules may be collected and separated from the liquid. In this embodiment, the granule basket 117a may be a cylindrical basket, open in the top end covered by a mesh119" for preventing food scrapes or cutlery etc to enter into the basket 117a. The basket 117a is perforated by recesses or holes 120a around the basket. The recesses or holes may be sufficiently wide to allow the passage of liquid but small enough to prevent the passage of granules. The granule basket 117a, which is preferably made of any suitable metal or plastic material, may comprise a larger cylindrical upper portion 121a and a smaller cylindrical lower portion 122a assembled together. The larger cylindrical upper portion is both higher and has a larger diameter than the smaller cylindrical lower portion. In this embodiment, the basket may be provided with two arched or rectangular wire bows 123a, 123b projecting from opposite sides of the envelope surface of the smaller cylindrical lower portion 122a. The basket may be provided with a handle 124a for easy insertion and removal of the granule basket 117a by hand from the dishwasher 100.
The granule valve 118a, which may be arranged in the dishwasher as shown in FIG. 1, is illustrated in further detail in FIG 12A. In this embodiment the granule valve may comprise a wire stand 125a arranged on a branch conduit 126a. The wire stand 125a may comprise an upper part corresponding to the larger cylindrical upper portion 121a and a lower part corresponding to the smaller cylindrical lower portion of the basket 117a. A pipe joint 128a is provided in the lower part of the branch conduit for connection to the conduit system 104, wherein the flow of liquid, with or without granules, may be drawn by means of the liquid pump 109 when the dishwasher is in an operating mode. Moreover, a draining pipe 129a is provided in the lower part of the branch conduit for connection to the draining pump 115.
The wire stand 125a may have two opposite bent portions 130a, 131a of at least one circular wire of the wire stand 125a for receiving the wire bows 123a, 123b of the granule basket 117a for connection of the granule valve 118a to the granule basket 117a. The wire stand 125a may be assembled to the branch conduit 126a by means of a knurled nut 132a for easy disassembling/assembling in case of cleaning of the granule valve. The branch conduit 126a may have a perforated filter plate or mesh arranged either on a top inlet of the conduit 126 or within the conduit.
The granule valve 118 further comprises a valve push rod 133a, which extends from the bottom of the branch conduit 126a and the wire stand 125a. The valve push rod 133a is provided with a valve cone 134a at the top end thereof forming a valve plunger, which is arranged to open and close the granule valve arrangement, as will be described below.
As shown in FIG. 13A the granule basket 117a is removably arranged on the granule valve 118a forming a granule valve arrangement, wherein the wire bows 123a, 123b of the granule basket have been inserted in the corresponding opposite bent portions 130a, 131a of the wire stand 125a of the granule valve 118a by turning the granule basked until the bent portions 130a, 131a reach a vertical wire of the wire stand. A sensor 135a, such as a magnetic or magneto-optical sensor, may be arranged in the washing tank 103a in order to detect whether the granule basket is attached to the granule valve 118a. The sensor 135 is operatively connected to the circuitry of the electrical cabinet 114 and configured to generate a sensor signal indicating whether the granule basket 117a is located and available for providing granules to the liquid depending on the washing program in operation.
FIG. 15A illustrates the granule valve arrangement including the removable granule basket 117a assembled with the granule valve 118a inserted in the dishwasher in an operative position. The basket is arranged in a hole 119a' in the bottom of the sink 106a, wherein the circular top end 119a of the granule basket is located at the same level as the bottom of the sink. The hole 119a' in the bottom of the sink and the circular top end 119a have corresponding diameters, so that granules cannot pass there between into the washing tank 103a. Preferably, the circular top end 119a may have a flange that may rest on the edge of the hole 119a', when the granule basket is inserted into the dishwasher.
In this embodiment, a massive "puck" with a conical cavity is arranged as a valve head 136a on top of the valve cone 134a. In a closed position as is shown in FIG 15A, a cylindrical lower flange 137a of the valve head 136a rests around an aperture 138a on a bottom end 139a of the upper portion 121a of the granule basket 117a. The aperture 138a may preferably have a circular shape or any other suitable shape, such as oval or rectangular etc. The valve head 136a has a corresponding shape, and large enough to cover the aperture in a closed position. In some embodiments, the bottom end 139 may be perforated by recesses or holes similar to the recesses or holes in the envelope of the cylindrical granule basket 117a. The recesses or holes may be sufficiently wide to allow the passage of the liquid flow but small enough to prevent the passage of granules. Advantageously the cylindrical lower flange 137a prevents granules from getting caught between the valve head 136a and the bottom end 139a when the granule valve 118a is moved to a closed position by a downward movement of the valve push rod 133.
An upward or downward movement of the valve push rod 133a for opening and closing of the granule valve is generated by the valve lifter arrangement 141, 142 as described above in connection with the embodiment of FIG. 15.
FIG. 16 shows an embodiment of a ware holder or tray 150 adapted for loading articles, such as pots and pans or other articles for coarse washing when the tray is inserted into a dishwasher, such as the dishwasher 100 in FIG. 1. The tray may have a rectangular frame 151 and transverse bars 152. The frame 151 may have elongated cuts 153 along the sides of the frame 151 to keep pots and pans etc in position during a washing cycle. The bars may be bended in the bottom to keep pots and pans in position during washing. Few bars are provided to manage heavy pots and pans and at the same time avoid shadows from the wash spray which can influence the wash result. Magnets 154 may be provided at each side or corner of the frame 151. Corresponding sensors (not shown) are provided in the dishwasher and operatively connected to the circuitry of the electric cabinet for detecting the magnets of the tray, i.e indicating if the basket is in or out of the dishwasher. In response to the sensors detecting that the tray is located in the dishwasher, the washing program may add granules to the liquid during the dishwashing cycle.
As mentioned above, the dishwasher is configured to operate according to one or more different washing programs. Initially, the rinse tank is filled with liquid, which may be heated before it is sprayed into the washing chamber to fill up the washing tank with liquid, preferably via the spray arm. As described above, the liquid may include but is not limited to dishwater, or water and detergent, or any other suitable liquid for dishwashing, which is used for several dishwashing cycles before the liquid in the washing tank need to be exchanged.
FIG 17 is a flow chart illustrating a method for operating a dishwashing apparatus according to one embodiment. As described above, the electric cabinet 114 may contain circuitry and/or a program-control device configured to run one or more different washing programs for operating the dishwashing apparatus to run a washing cycle in response to user input via the user interface 116.
The method includes, but is not limited to, at least one washing cycle including dishwashing and rinsing. Before starting the dishwashing program a tray with articles to be washed may be inserted into the chamber 102 and the hood 107 is closed. A dishwashing program to initiate a washing cycle is started via the interface of the control panel 116. The rinse tank 103b may preferably be refilled by fresh water or other suitable rinsing liquid, which may be warmed up by a heater in the rinse tank for each washing cycle. The fresh liquid may be supplied from an external fresh water supply or another external liquid reservoir that may be connected to the rinse tank. The liquid may be supplied to the washing tank via the washing liquid conduit system and the spray arms or via a separate conduit in connection with the tank.
According to one embodiment, the liquid pump 109 is started at a low speed in an initial step, which leads to a low liquid pressure and flow. A detector or sensor arranged within the chamber as described above is activated for detecting what type of ware holder that has been placed in the chamber in step 401.
In response to that a ware holder or tray 150 adapted for pot-washing is detected in step 401 by means of sensors in the dishwasher detecting the magnets 154 on the tray, and that the granule basket 117,117a is detected by means of the sensor 135, the liquid pump 109 is controlled to provide high water pressure together with granules thorough the spray arms and spray nozzles as described above. Hence, the granules are added to the liquid in the dishwasher by controlling 402 the granule valve 118, 118a to open after a few seconds, if desired and enabled by the current dishwashing program, for dishwashing with granules 403. Liquid with granules is pumped from the washing tank through the washing liquid conduit system and the spray arms on to the articles in the ware holder. Although, the liquid in the washing tank has been pre heated in the rinse tank, maintenance heating of the liquid may be provided by the heater in the washing tank for improved washing result. Before the end of a washing program with granules, the granule valve 118 is controlled 404 to close the valve. Although, the granules will be collected almost immediately in the granule basket 117, the dishwashing program continues for a short while, typically a few seconds to secure that all of the granules are collected. Then, the dishwashing program continues with rinsing 405 with liquid pumped from the rinse tank through the rinse liquid conduit system and the spray arms on to the articles in the tray. When the rinsing ends the dishwashing program may be finished, and the operator may open the hood 107 to remove the tray 150 with the clean dish.
However, if a ware holder for standard washing is provided, the granule valve 118 should be closed and the liquid pump 109 is controlled to provide low water pressure during dishwashing 406. The dishwashing program continues with rinsing 407 with liquid pumped from the rinse tank through the rinse liquid conduit system and the spray arms on to the articles in the tray. When the rinsing ends the dishwashing program may be finished, and the operator may open the hood 107 to remove the tray 150 with the clean dish.
Embodiments of the present invention have been described herein with reference to dishwashing programs. It will be understood that washing programs may be implemented in the form of an entirely hardware embodiment, or an embodiment combining software and hardware aspects including computer program instructions to control the dishwasher. These computer program instructions may be provided to a processor of the program-control device, a general purpose computer, special purpose computer, or other programmable data processing apparatus of the dishwasher to produce a machine, such that the instructions when executed create means for implementing the specified functions/acts of the washing programs to operate the dishwasher accordingly.
The features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention, which fall within the scope of the technology. For example, the dishwasher may be provided with either a single rotatable spray arm arranged in the upper part or in the lower part in other embodiments. Other configurations with one or more spray arms arranged within the chamber are possible within the scope of the present patent claims.
In addition, singular references do not exclude a plurality. The terms "a", "an", "first", "second" etc do not preclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.

List of feature elements:

granule dishwasher 100
stand 101
dishwashing chamber 102
washing tank 103 a
rinse tank 103b
conduit system 104
washing liquid conduit system 104a
rinse liquid conduit system 104b
back wall 105
sink 106
hood 107
handles 108
liquid pump 109
upper rotatable spray arm 110
lower rotatable spray arm 111
rinsing pipe 112
dishwashing pipe 113
electric cabinet 114
draining pump 115
control panel 116
granule container or basket 117, 117a
granule valve 118, 118a
top end 119, 119a
hole 119', 119a'
mesh119"
recesses or holes 120, 120a
larger cylindrical upper portion 121, 121a
smaller cylindrical lower portion 122, 122a
pin 123
wire bows 123a, 123b
handle 124, 124a
cylindrical sleeve 125
wire stand 125a
branch conduit 126, 126a
perforated filter plate 127
pipe joint 128, 128a
draining pipe 129, 129a
vertical recesses 130, 131
bent portions 130a, 131a
knurled nut 132, 132a
valve push rod 133, 133a
valve cone 134, 134a
sensor 135
valve head 136, 136a
chamfered edge 137
cylindrical lower flange 137a
circular aperture 138, 137a
bottom end 139, 139a
recesses or holes 140
electric motor 141
hinged lever arrangement 142
tray 150
frame 151
transverse bars 152
elongated cuts 153
magnets 154
surface member 200
elongated casing 202
center section 203
spray jets or holes 204
first edge 205a
second edge 206a
third edge 205b
fourth edge 206b
rinsing inlet 220
dishwater inlet 222
filter 225
rinsing channel 230, 231
washing channels 232-237
end portions 242-244
surface member 300
casing 302
centre section 303
an inlet connection 303a
spray jets or holes 304
first edge 305a
second edge 306a
spray nozzles 312a-f
side walls 315, 316, 318, 319
rinsing inlet 320
dishwater inlet 322
O-ring sealing 325
recessed flange 326
top edge 327
rinsing channels 330, 331
washing channels 332-337
spray arm 348
screw fastening 350

Claims

A granule valve arrangement for a granule dishwashing apparatus, comprising a removable granule basket (117;117a) removably arranged on a granule valve (118;118a), said granule valve (118;118a) is arranged to be altered between a closed position and an opened position, characterized in that in the closed position a valve head (136; 136a) covers an aperture (138; 138a) in the bottom (139;139a) of the granule basket (117) for collecting granules in the granule basket (117;1 17a), and in that in the opened position the valve head (136;136a) is moved upwards so that granules can pass from the granule basket through the aperture in the bottom (139;139a) of the granule basket into the granule valve (118;118a).
The granule valve arrangement of claim 1, wherein the removable granule basket (117;117a) is a cylindrical basket, open in the top end (119) and perforated by recesses or holes (120;120a) around the basket, the recesses or holes are sufficiently wide to allow the passage of liquid but small enough to prevent the passage of granules.
The granule valve arrangement of claim 2, wherein the granule basket (117;117a) comprises a larger cylindrical upper portion (121;121a) and a smaller cylindrical lower portion (122;122a) assembled together, the larger cylinder upper portion is both higher and has a larger diameter than the lower smaller cylinder portion, the basket is provided with two pins (123) or wire bows (123a, 123b) projecting from opposite sides of an envelope surface of the smaller cylindrical lower portion (122;122a) for connecting the granule basket (117;117a) to the granule valve (118;118a).
The granule valve arrangement of any of the claims 1-3, wherein the granule basket (117;117a) is provided with a handle (124;124a) for insertion and removal of the granule basket (117;117a) by hand from a dishwasher (100).
The granule valve arrangement of any of the claims 1-4, wherein the granule valve (118) comprises an upper perforated open ended cylindrical sleeve (125) arranged on a branch conduit (126), the cylindrical sleeve (125) has recesses (130, 131) partly around portions of the cylindrical sleeve (125) for receiving the pins (123) of the granule basket (117) for connection of the granule valve (118) to the granule basket (117).
The granule valve arrangement of claims 5, comprising a wire stand (125a) arranged on a branch conduit (126a), wherein the wire stand (125a) comprises an upper part corresponding to the larger cylindrical upper portion (121a) and a lower part corresponding to the smaller cylindrical lower portion of the basket (117a), opposite bent portions (130a, 131a) of at least one circular wire of the wire stand (125a) for receiving the wire bows (123a, 123b) of the granule basket (117a) for connection of the granule valve (118a) to the granule basket (117a).
The granule valve arrangement of claim 5 or 6, wherein a perforated filter plate or mesh (127) is arranged within or on a top inlet of the branch conduit (126;126a), wherein the perforations are large enough to let both liquid and granules to flow in to the branch conduit (126;126a) but preventing food scraps and/or cutlery to limit or stop up the flow through the branch conduit.
The granule valve arrangement of any of the claims 5-7, wherein the granule valve (118;118a) comprises a vertical valve push rod (133;133a), which extends from the bottom of and through the branch conduit (126) and is provided with a valve cone (134) at the top end thereof forming a valve plunger.
The granule valve arrangement of claim 8, wherein the valve head (136) has a conical cavity arranged on top of the valve cone (134) and rests on a chamfered edge (137) around an aperture (138) in a bottom end (139) of the larger cylindrical upper portion (121) of the granule basket (117), wherein the valve head (136) has a shape large enough to cover the aperture (138), in a closed position.
The granule valve arrangement of claim 8, wherein the valve head (136) has a conical cavity arranged on top of the valve cone (134a) and a cylindrical lower flange (137a) of the valve head (136a) rests around an aperture (138a) on a bottom end (139a) of the upper portion (121a) of the granule basket (117a), in a closed position.
The granule valve arrangement of claim 9 or 10, wherein the bottom end (139;139a) is perforated by recesses or holes (140) sufficiently wide to allow the passage of the liquid flow but small enough to prevent the passage of granules.
The granule valve arrangement of any of the claims 8-11, comprising a valve lifter arrangement including an electric motor (141) operatively connected to a hinged lever arrangement (142) adapted to generating an upward and a downward movement of the valve push rod (133;133a) connected to the hinged lever arrangement (142) , wherein valve head (136;136a) is movable between the closed position for collecting granules in the granule basket (117;117a) and the open position so that granules can pass through the bottom of the granule basket.
A granule dishwashing apparatus, comprising a granule valve arrangement according to any of the claims 1-12.
The granule dishwashing apparatus of claim 13, comprising a dishwashing chamber (102), a washing tank (103a) and a rinse tank (103b) located below the dishwashing chamber, a conduit system (104) connecting the tanks (103a,103b) to the dishwashing chamber (102), and a sink (106) above the washing tank (103a), wherein the removable granule basket (117;117a) is removably arranged in a hole (119';119a') in the bottom of the sink (106), the circular top end (119;119a) of the granule basket is located at the same level as the bottom of the sink, and the hole (119') in the bottom of the sink and the circular top end (119) have corresponding diameters.
The granule dishwashing apparatus of any of the claims 13-14, comprising a rotatable spray arm (110, 111; 348), comprising an elongated surface member (200,300) and an elongated casing (202,302) on both sides of a center section (203,303), the surface member (200,300) and the casing (202,302) are assembled together forming an inside chamber of the spray arm (110,111; 348), wherein the inside chamber is divided in separate elongated washing channels (232-234, 235-237; 332-334, 335-337) provided on each side of the center section (203;303), said washing channels are connected to a dishwashing inlet (222;322) arranged to guide dishwashing liquid into the washing channels (232-234, 235-237; 332-334, 335-337) towards spray nozzles (212a-f;312a-g) at the end of each washing channel.
The granule dishwashing apparatus of any of the claims 13-15, comprising a sensor (135) arranged in the washing tank (103a) to detect whether the granule basket (117;117a) is attached to the granule valve (118;118a) in the dishwashing apparatus.
The granule dishwashing apparatus of claim 16, wherein the sensor (135) is operatively connected to the circuitry of the electrical cabinet (114) and configured to generate a sensor signal indicating whether the granule basket (117) is located and available for providing granules to the liquid depending on the washing program in operation.
The granule dishwashing apparatus of claim 16 or 17, wherein the sensor (135) is a magnetic or magneto-optical sensor.
A method for operating a dishwashing apparatus as claimed in one of the claims 16-18, comprising:
initiating (400) the liquid pump (109) for providing liquid with low liquid pressure;

detecting (401) a ware holder (150) adapted for coarse washing in the chamber (102), and that the granule basket (117,117a) is attached to the granule valve (118,118a);

controlling (402) the granule valve (118,118a) to open for adding granules to the liquid;

dishwashing with liquid and granules (403);

controlling the granule valve (118,118a) to close for collecting the granules in the granule basket (117, 117a); and

rinsing (405) the ware holder.