Patent Description:
It is commonly known to use different types of valves for controlling food product intake and/or outtake of containers or tanks, e.g., mixers or filling machines, in the food processing industry. The valves are configured to control a food product flow to and/or from the containers or tanks and thereby also controlling the intake and/or outtake. Equipment used in the food processing industry need to be designed so that it can be efficiently cleaned.

Even though food processing equipment and especially valves have been used in the food processing industry for decades, there is room for improvement for obtaining better cleaning. A further challenge is the durability of the valve, including the durability of the gaskets of the vales which are exposed to wear and tear.

For these reasons, there is a demand for a valve that fulfills the requirements related to the food processing industry, e.g., hygienic design as well as food safety. There is also a demand for a valve with improved durability and cleanability such that the valve life is increased compared to conventional valves.

Examples of valves and processing equipment are described in patent documents <CIT>, <CIT>, <CIT> and <CIT>.

It is an object to at least partly overcome one or more of the above-identified limitations of the prior art. In particular, it is an object to provide a valve for efficiently controlling a product flow which while still assuring it is easy to clean.

According to embodiments of the valve, other objects may be to provide a valve with improved durability and thereby increased cost-efficiency, a valve which facilitates improved flow capacity and/or a valve which is configured to be easily retrofitted to existing food processing equipment.

According to a first aspect, it is provided a valve for controlling a product flow, the valve comprising a valve body having a product inlet, a product outlet, a product flow channel formed between the product inlet and the product outlet, and a valve seat arranged in the product flow channel; a rotatable stem extending through a wall of the valve body and into the product flow channel with an end portion of the stem disposed within the product flow channel; and a disk arranged at the end portion of the stem at an angle greater than zero relative to an elongated extension of the stem, the disk being movable from a closed position where it abuts the valve seat for sealing the valve closure area, to an open position by rotating the stem approximately <NUM>°, wherein the valve body comprises a stem seal groove having a stem seal that surrounds the stem for providing sealing between the valve body and the stem, and a void space surrounding the stem and extending from the stem seal to the product flow channel, such that the stem seal is fluidly connected to the product flow channel via the void space. The void space has, in a radial direction of the stem, an extension that has a length that is at least <NUM>% of a thickness of the stem, where the thickness of the stem is measured across the stem in the radial direction. The extension is measured on a side of the stem that is opposite the product flow channel.

The valve is preferably configured to control a product being a powder food product. However, it should be noted that the valve may also control a product being a liquid food product. The valve is for controlling the product flow, typically for controlling product intake and/or outtake of containers or tanks in the food processing industry.

The void space should be understood as a geometrical shape that defines its surrounding, i.e. it is a technical design parameter that gives the valve certain technical characteristics. The void space is therefore created to let its geometrical shape define the shape of the parts of the valve that surround the void space.

In this context, the term controlling should be interpreted as the valve is configured to open the product flow channel, by moving the disk to the open position, such that the product may flow through the valve, and to close the product flow channel, by moving the disk to the closed position. In addition, the valve is configured to move the disk between the open and closed positions such that the disk may be arranged in positions being between the open and closed positions, thereby adjusting the flow path of the product through the valve. Thus, by being able to control the valve, it is possible to control a cross section which in turn provides the ability to control the flow rate given the same differential pressure. Put differently, the valve is configured to control the flow between two positions. The valve is advantageous in that it is possible to move the disk from the closed position to the open position in an easy and efficient way by rotating the stem approximately <NUM>°. Herein, the term "approximately <NUM>°" should be interpreted as the stem should be rotated <NUM>-<NUM>°, preferably <NUM>-<NUM>°, more preferably <NUM>-<NUM>°, even more preferably <NUM>-<NUM>°. When the disk is in the closed position, it abuts the seal, in other words being transverse to a principal product flow at a location of the disk. When the disk is in the open position, it is arranged along the principal product flow at a location of the disk. Having the present arrangement of the disk, when in the open position, is advantageous in that it allows for a reduced pressure drop of the product flow, when flowing through the valve, compared to conventional valves, such as butterfly valves and ball valves.

At least a portion of the stem which is present in the product flow channel may be flat-shaped. This provides for an increased flow capacity due to a larger open pipe area compared to stems being rounded stems. The larger open area is formed by having a cross-section of the stem, along the principal product flow, which is minimized due to the stem being flat-shaped, when the disk is in the open position, compared to rounded stems.

The valve is further advantageous in that it allows for an improved cleanability compared to conventional valves which is an important requirement within the food processing industry. This is achieved by the disclosed void space which is surrounding the stem of the valve. By having the void space, it is possible to flush cleaning fluid in the void space such that the cleaning fluid may be in direct contact with the stem seal to thereby achieve improved cleanability. In addition, this also provides for that an improved hygienic design is achieved.

The void space facilitates clean-in-place (CIP) technology to be used in an easy and efficient way when cleaning the valve, wherein the CIP technology is able to provide a complete cleaning processes.

The valve is yet further advantageous in that the stem is introduced through the wall of the valve body which thereby prevents penetrating sealing elements that may be comprised in the valve in order to provide for a tight sealing of the valve, as is the case in a conventional butterfly valve. By preventing penetration of sealing elements of the valve, the sealing elements are exposed to a reduced amount of wear and tear compared to a solution in which sealing elements are penetrated. Thereby, a durable valve is achieved having an increased lifetime.

The valve is yet further advantageous in that it is possible to retrofit the valve to existing food processing equipment. Thus, it is possible to replace existing valves of food processing equipment with the disclosed valve without the need of replacing the equipment itself.

The void space may have an extension of at least <NUM> in a radial direction of the stem. This is advantageous as it enables for the cleaning fluid to be in direct contact with the stem seal in an efficient way such that a complete cleaning process is possible. Preferably, the extension may be at least <NUM> in the radial direction of the stem.

The void space may have a shape of a hollow body with a truncated section at a first end thereof and a base section at a second opposite end thereof, where a first portion of the base section extends into the wall of the valve body, and wherein a second portion of the base section is adjacent the product flow channel.

The hollow body with the truncated section may also be defined as that the hollow body of the void space having had a portion cut off opposite the base section. This is advantageous in that it allows for the void space to be designed in a desired way depending on the design of the valve body and the introduction of the stem through the wall of the valve body.

The second portion of the base section is opposite to the first portion of the base section and wherein the second portion may be in direct contact with the product flow channel. This is advantageous in that it allows for improved cleanability.

A peripheral part of the stem seal may face the base section of the void space, to thereby define a ring-shaped area partially defining the void space.

It should be understood that the peripheral part of the stem seal is the peripheral part seen in an axial direction. It should be noted that, when the peripheral part of the stem seal is facing the base section of the void space, other shaped-areas partially defining the void space may be defined as well. The shape of the shaped-area may depend on the design of the stem seal. This is advantageous in that it allows for a stable seal to be formed, thereby avoiding, or at least reducing, the risk of that a leak past the stem seal occurs. This is further advantageous in that, as said above, it is possible to provide for an efficient cleaning process, thereby ensuring that a hygienic design of the valve is achieved.

The void space may have the shape of a truncated, hollow cylinder, where the rotatable stem extends through the void space.

It should be understood that the truncated, hollow cylinder and the hollow section are geometrical shapes and that the void space being formed by the hollow cylinder and that the stem extends through the hollow cylinder. The hollow section defines where the stem is arranged though the hollow cylinder. Preferably, the hollow section of the hollow cylinder is centrally arranged such that void space has a uniform extension in the radial direction, seen from the stem to the valve body. Thus, the stem is preferably introduced through a central portion of the void space.

This is advantageous as it allows for an efficient and uniform CIP in order to remove contamination along the complete stem seal and stem.

The valve body may comprise a removable stem holder radially surrounding a portion of the stem and being configured to hold the stem in relation to the valve body, wherein the stem seal groove is located between the stem holder and the valve body.

This is advantageous in that the stem seal is able to provide for a strong and stable seal between the stem holder and the valve body such that a risk of a leakage to occur past the stem seal is avoided or at least reduced.

The stem holder is advantageous in that it allows for the stem to be efficiently kept in place in relation to the valve body.

The stem holder may comprise a leakage detecting hole that extends through the stem holder, in a radial direction of the stem, for providing detection of leakage past the stem seal.

This is advantageous in that it allows for possible leakage to be detected as early as possible thereby also minimizing potential damage as much as possible. Thus, this provides for an easy and efficient leakage detection of the valve.

The valve seat may comprise a main seal groove in which a main sealing element is arranged. This is advantageous as it allows for a strong and stable seal between the valve seat and the disk, when the disk is in the closed position, such that a risk of a leakage to occur past the main sealing element is avoided or at least reduced.

The sealing element may be made of an elastic and durable material. The sealing element may be made of polyurethane. The sealing element may have a shape which provides for an easy movement of the disk into the closed position. This is advantageous in that a durable seal is provided and thereby also an increased lifetime of the seal.

The valve body may comprise two opposite leakage detection passages that extend from the main seal groove, to an outer surface of the valve body for providing detection of leakage past the main sealing element. This is advantageous in that it allows for possible leakage to be detected as early as possible thereby also minimizing potential damage as much as possible. Thus, this provides for an easy and efficient leakage detection of the valve. The two opposite leakage detection passages may be axially aligned with a center of the product flow channel.

The valve body may comprise a first part, a second part and a third part that are connected to each other by attachment devices and with the second part arranged between the first part and the third part, the main seal groove being formed between the first part, the second part and the third part.

By having the main seal groove formed between the three parts facilitates that a strong and efficient seal is provided between the different parts as well as between the valve body and the disk, when the disk is in the closed position.

The attachment devices may be formed by a clamp and a bolt. The attachment devices may be any of these or any other suitable devices for connecting two pipe components to each other. The third part of the valve may form a part of a food processing equipment, for example by being welded to the food processing equipment. This makes the valve suitable for retrofitting to existing food processing equipment, in particular for equipment that already has the third part installed. I this case the third part could have been a part of a conventional butterfly valve that was previously used for the equipment.

When the disk is in the open position, the disk may, as seen along the product flow channel, extend past the product outlet.

The leakage detection passages may be formed in the third part. This facilitates stable and efficient leakage detection, where it is possible to detect if a leakage has occurred past the main sealing element of the valve body.

The main sealing element may have an extension seen along the product flow channel which is at least three times a thickness of the disc. This is advantageous in that it enables for a strong and stable seal to be provided when the disk is in the closed position. This is also advantageous in that more material to wear from is provided compared to conventional valve seals. Thereby, an increased lifetime of the seal is achieved.

According to a second aspect, it is provided a mixing unit for mixing a liquid food product with a powder food product. The mixing unit comprising a tank comprising a liquid inlet configured to receive the liquid food product to the tank and an powder inlet configured to receive the powder food product to the tank, a vacuum source connected to the tank and configured to apply a vacuum to the tank, a valve connected to the powder inlet and configured to control a vacuum induced flow of the powder food product into the tank via the powder inlet, and an agitator arranged inside the tank and configured to agitate the liquid food product and the powder food product, wherein the valve is a valve according to the first aspect.

This is advantageous in that it allows introducing the powder food product into the mixing unit in an easy and efficient way. It is also possible to control the product flow of the powder food product in an efficient way.

According to a third aspect, it is provided a method for mixing a liquid food product with a powder food product. The method comprising feeding the liquid food product to the tank of a mixing unit, the liquid food product having a liquid surface inside the tank; applying a vacuum to the tank by using a vacuum source; feeding the powder food product to the tank of the mixing unit via a disc valve of the mixing unit, when the liquid surface is above the powder inlet such that the powder food product is fed to the tank below the liquid surface; and agitating the liquid food product with the powder food product by using the agitator, wherein the mixing unit is a mixing unit according to the second aspect.

Effects and features of the second and third aspects are largely analogue to those described above in connection with the first aspect.

Still other objectives, features, aspects and advantages will appear from the following detailed description as well as from the drawings.

Embodiments will now be described, by way of example, with reference to the accompanying schematic drawings, in which.

With reference to <FIG> a mixing unit <NUM> is illustrated. The mixing unit <NUM> comprises a tank <NUM> that has a liquid inlet <NUM> for receiving various liquid food products. A number of sources <NUM>-<NUM> that hold the liquid food products are connected to the liquid inlet <NUM> via valves <NUM>-<NUM> that control the supply of the liquid food products through the liquid inlet <NUM> and into the tank <NUM>. It should be noted that the mixing unit <NUM> may be configured to receive less than five liquid food products or more than five liquid food products via the liquid inlet <NUM>. The tank <NUM> has a powder inlet <NUM> having a valve <NUM> connected thereto for receiving a powder food product. The valve <NUM> is arranged for controlling the flow of the powder food product through the powder inlet <NUM> and is further discussed in connection with <FIG>. A powder source <NUM> that holds the powder food product is connected to the inlet <NUM>. The mixing unit <NUM> is configured to mix the liquid food products with the powder food product to form a food product.

The mixing unit <NUM> has at its bottom <NUM> an outlet <NUM> through which mixed food product may leave the tank <NUM>, for example by opening an outlet valve <NUM>. To facilitate introducing liquid and/or powder food products into the mixing unit <NUM>, the mixing unit <NUM> may comprise a pressure arrangement that inside the tank <NUM> creates a pressure that is lower than a pressure of the atmosphere surrounding the tank <NUM>. To make mixed food products, or typically a finished food product, efficiently leave the mixing unit <NUM>, the pressure arrangement may inside the tank <NUM> create a pressure that is higher than a pressure of the atmosphere surrounding the tank <NUM>. Additionally or alternatively, one or more pumps may be arranged for feeding the food product into the tank <NUM> respectively for drawing out a content of the tank <NUM>, such as a finished mayonnaise product.

The pressure arrangement may be a vacuum source <NUM> as illustrated in <FIG>. The vacuum source <NUM> is connected to the tank <NUM> and is configured to apply a vacuum to the tank <NUM> to introduce the powder food product into the tank in an efficient way. The valve <NUM>, which is connected to the powder inlet <NUM>, is configured to control a vacuum induced flow of the powder food product into the tank <NUM> via the powder inlet <NUM>.

A jacket <NUM> surrounds a periphery of the tank <NUM> and has an inlet respectively an outlet (not shown) for allowing a cooling or heating media to flow through the jacket <NUM> for decreasing or increasing a temperature of food product that are present inside the tank <NUM>.

A double shaft agitator <NUM> is located inside the mixing unit <NUM> and has a double shaft axle <NUM>, <NUM> that is suspended from the top of the tank <NUM>. The double shaft axle has a first axle <NUM> that encloses an upper part of a second axle <NUM>, and the two axles <NUM>, <NUM> are driven to rotate in same or different directions R1, R2 by a motor unit <NUM> that is arranged at the top of the mixing unit <NUM>. The two axles <NUM>, <NUM> extend along and are rotatable about a first rotational axis A1 of the mixing unit <NUM>.

A fist blade <NUM> is via an arm <NUM> connected to the first axle <NUM> so that the first blade <NUM> rotates in the same direction R1 as the first axle <NUM> when driven by the motor unit <NUM>. The first blade <NUM> may be a scraper blade that rotates close to an inner wall of the tank <NUM>, so that food product that stick to the inner tank wall may be scraped off.

A second blade <NUM> is via an arm <NUM> connected to the second axle <NUM> so that the second blade <NUM> rotates in the same direction R2 as the second axle <NUM> when driven by the motor unit <NUM>. The second blade <NUM> may be a fluid lifting blade in the sense that it is arranged to make food product in contact with the second blade <NUM> flow upward from the bottom <NUM> of the tank <NUM> in a direction towards the top of the tank <NUM> when the second axle <NUM> is driven by the motor unit <NUM>. Any suitable numbers of fluid lifting blades like the second blade <NUM> may be connected to the second axle <NUM>, such as four blades, as shown in the illustrated example.

A rotor <NUM> is arranged at the bottom <NUM> of the tank <NUM>. The rotor <NUM> is via an axle <NUM> connected to a rotor engine <NUM> that, when activated, drives the axle <NUM> so that the rotor <NUM> rotates in a rotational direction R3. The axle <NUM> of the rotor <NUM> extends along and is rotatable about a second rotational axis A2 of the mixing unit <NUM>. The two axes A1 and A2 are preferably aligned with each other. A stator <NUM> is arranged around the radial periphery of the rotor <NUM>. An actuator <NUM> is arranged to move the stator <NUM> in a direction D that is parallel to the axis of rotation A2 of the rotor <NUM>. The actuator <NUM> can set the stator <NUM> in a lowermost position where it surrounds the radial periphery (circumference) of the rotor <NUM>. The stator <NUM> can then, by the actuator <NUM>, be moved to an uppermost position where it is lifted such that it does not surround the radial periphery of the rotor <NUM>. The stator <NUM> has openings where it surrounds the circumference of the rotor <NUM>, thereby allowing food product to be pushed through the stator when the stator <NUM> in an a position where it surrounds all of or some of the rotor <NUM>.

The rotor <NUM>, the stator <NUM> and the actuator <NUM> form a rotor-stator arrangement <NUM> that allows a shear that food product are subjected to, by the rotor <NUM> and the stator <NUM>, to be varied when the rotor <NUM> rotates. In detail, when the stator <NUM> is in its lowermost position (closest to the bottom <NUM> of the tank <NUM>), food product inside the tank <NUM> are by the rotation of the rotor <NUM> drawn towards the upper side of the rotor <NUM>. The food product are then forced outwards in a radial direction of the rotor <NUM>, through the holes in the stator <NUM> that surround the circumference of the rotor <NUM>.

When the stator <NUM> is in its uppermost position (farthest away from the bottom <NUM> of the tank <NUM>), food product inside the tank <NUM> are by the rotation of the rotor <NUM> drawn towards the upper side of the rotor <NUM>. The food product are still forced outwards in a radial direction of the rotor <NUM>, but without passing through the holes in the stator <NUM> since the stator <NUM> does not surround the circumference of the rotor <NUM>. The stator <NUM> can be positioned at any location between its lowermost position and its uppermost position, which will vary the amount of food product that pass through the stator <NUM>. The more food product that pass though the stator <NUM>, the higher the shear will be. Thus, due to the actuator <NUM> and the movable stator <NUM> it is possible to vary a shear that is provided by the rotor <NUM> and the stator <NUM> during mixing of any ingredient inside the mixing unit <NUM>.

<FIG> illustrates an exploded view of the valve <NUM> as introduced in connection with <FIG>. <FIG> illustrates an assembled view of the valve <NUM>.

With reference to <FIG> and <FIG>, the valve <NUM> comprises a valve body <NUM> having a product inlet <NUM>, a product outlet <NUM>, and a product flow channel <NUM> formed between the product inlet and outlet <NUM>, <NUM>. The product flow channel <NUM> has an flow channel extension FCE.

The valve body <NUM> is formed by a first part 210a, a second part 210b and a third part 210c. In <FIG>, the parts 210a-c are separated from each other. In <FIG>, the parts 210a-c are connected to each other by attachment devices 219a, 219b. The attachment devices 219a, 219b are formed by a clamp 219a and a bolt 219b, wherein the clamp 219a is for connecting the first and second parts 210a-b. In the depicted figure, one bolt 219b is illustrated but also four bolt holes. Thus, the second and third parts 210b, 210c may be connected via four bolts 219b according to the present figure. The bolts 219b may be entered through openings in the second part 210b and screwed into threaded holes <NUM> in the third part 210c to thereby attach the second and third parts 210b, 210c to each other. Other attaching devices suitable to connect the parts 210a, 210b, 210c of the valve body <NUM> may be used as well. It should be noted that the valve body <NUM> may be formed by more than three parts or by less than three parts as well. The third part 210c may form a part of the mixing unit <NUM> in <FIG>, for example by being welded to the mixing unit <NUM>.

The valve body <NUM> comprises a valve seat <NUM>. The valve seat <NUM> comprises a main seal groove <NUM> in which a main sealing element <NUM> is arranged. The main seal groove <NUM> extends along the parts 210a, 210b, 210c of the valve body <NUM>. In the depicted figure, the main sealing element <NUM> is provided with a protrusion in order to fasten the main sealing element <NUM>.

The third part 210c of the valve body <NUM> comprises two opposite leakage detection passages 218a, 218b. The leakage detection passages 218a, 218b extend from the main seal groove <NUM> to an outer surface of the valve body <NUM>. The leakage detection passages 218a, 218b are arranged for providing detection of leakage past the main sealing element <NUM> of the valve <NUM>. Preferably the leakage detection passages 218a, 218b are provided in the boundary between the second part 210b and third part 210c of the valve body <NUM>.

The valve <NUM> further comprises a rotatable steam <NUM>. The stem <NUM> comprises an end portion 221a and a further end portion 221b. In <FIG>, the stem <NUM> extends through a wall <NUM> of the first part 210a of the valve body <NUM> such that the end portion 221a of the stem is disposed within the product flow channel <NUM>. The stem <NUM> is arranged with an angle β relative to the valve body <NUM>.

The valve body <NUM> further comprises a removable stem holder <NUM> which is configured to receive the other end portion 221b of the stem <NUM> in order to hold the stem <NUM> in place in relation to the valve body <NUM>. The valve <NUM> further comprises a stem seal groove <NUM> in which a stem seal <NUM> is arranged. The stem seal groove <NUM> is located between the steam holder <NUM> and the valve body <NUM> and the stem seal <NUM> is configured to seal between the stem holder <NUM> and the valve body <NUM>. The stem holder <NUM> comprises a leakage detecting hole 224a, 224b. The leakage detection hole 224a, 224b extends through the stem holder <NUM>, in the radial direction R (see <FIG>). The leakage detecting hole 224a, 224b is arranged for providing detection of leakage past the stem seal <NUM>. The stem <NUM> has an elongated extension STE.

The valve <NUM> further comprises a disk <NUM> which is arranged at the end portion 221a of the stem <NUM>. As best illustrated in <FIG>, the disk <NUM> is arranged at the end portions 221a of the stem <NUM> at an angle α which is greater than zero in relation to the elongated extension STE of the stem <NUM>. The disk <NUM> is movable from a closed position P1, as illustrated in <FIG>, to an open position P2, as illustrated in <FIG>. The disk <NUM> is moved by rotating the stem <NUM> approximately <NUM>°. The stem <NUM> may be rotated in different ways, such as <NUM>-<NUM>°, preferably <NUM>-<NUM>°, more preferably <NUM>-<NUM>°, even more preferably <NUM>-<NUM>°.

The stem <NUM> may be the only structure that holds the disk <NUM>. This may mean that there is, in the valve body <NUM>, only one through hole or opening that is used for the purpose of providing support for the disk <NUM>.

As further illustrated in <FIG>, the valve body <NUM> further comprises a void space <NUM>. The void space <NUM> surrounds the stem <NUM> and extend from the stem seal <NUM> to the product flow channel <NUM>. Thereby, the product flow channel <NUM> is in direct contact with the stem seal <NUM>. Put differently, the stem seal <NUM> is fluidly connected to the product flow channel <NUM> via the void space <NUM>. The void space <NUM> is further illustrated and discussed in connection with <FIG> and <FIG>.

The disk <NUM> is arranged in the closed position P1 in which the disk <NUM> abuts the valve seat <NUM>. In this position, the product flow channel <NUM> is blocked by the disk <NUM> in order to prevent product to flow through the valve <NUM>. When the disk <NUM> is arranged in the closed position P1 and abuts the valve seat <NUM>, it is arranged to seal the valve closure area <NUM> such that the valve <NUM> is tight between the disk <NUM> and the valve body <NUM>.

The disk <NUM> has a thickness DT as seen along the product flow channel <NUM>, when the disk <NUM> is in the closed position P1. The main sealing element <NUM> has an extension SEE along the product flow channel <NUM>. Preferably, the main sealing element <NUM> has an extension which is at least three times the thickness of the disk <NUM>.

With reference to <FIG>, further to what have been discussed above, the disk <NUM> of the valve <NUM> is arranged in the open position P2. As illustrated, when the disk <NUM> is in the open position P2, a main extension MED of the disk <NUM> is arranged in parallel to the product flow channel <NUM>. In other words, a main extension MED of the disk <NUM> is arranged in parallel to a principal product flow at a location of the disk <NUM>.

As further illustrated in <FIG>, the valve seat <NUM> has a seating area. In this context, the valve seat <NUM> is arranged to define a valve closure area <NUM> having the same angle α relative to the elongated extension STE as the valve disk <NUM>. The angles α and β may be equal, which is the preferred design. This is true in the case when angles α, β are <NUM>°. In other cases, the angles α, β may be different degrees but should together preferably be <NUM>°.

In <FIG>, showing section <NUM> of <FIG>, the void space <NUM> as introduced in <FIG> is illustrated in further detail by way of examples. The void space <NUM> surrounds the stem <NUM>. The void space <NUM> extends from the stem seal <NUM> to the product flow channel <NUM> such that the stem seal <NUM> is fluidly connected to the product flow channel <NUM> via the void space <NUM>. The void space <NUM> facilitates cleaning of the valve <NUM>, wherein cleaning fluid is able to be flushed to the stem seal <NUM> thereby being in directed contact with the stem seal <NUM>. This provides for an improved cleanability compared to conventional valves.

The void space <NUM> has an extension VE of at least <NUM> in a radial direction R of the stem <NUM>. The void space <NUM> may have other extensions, such as at least <NUM>.

The void space <NUM> has, in a radial direction R of the stem <NUM>, an extension VE that has a length that is at least <NUM>% of a thickness DM of the stem <NUM>, where the thickness DM of the stem <NUM> is measured across the stem <NUM> in the radial direction R. The extension VE and the thickness DM may be measured at the same longitudinal position on the stem <NUM>, as seen in a direction along the elongated extension STE. The extension VE is measured on a side of the stem <NUM> that is opposite the product flow channel <NUM>. The void space <NUM> may have, in the radial direction R of the stem <NUM>, an extension VE that has a length that is even longer, such as at least <NUM>% or even at least <NUM>% of the thickness DM of the stem <NUM>. Having an extension VE that is at least <NUM>% of the thickness DM is advantageous in that a peripheral part 225a of the stem seal <NUM> may be more efficiently cleaned.

As best illustrated in <FIG>, the void space <NUM> has a shape of a hollow body <NUM> with a truncated section <NUM>, at a first end thereof, and a base section <NUM>, at a second opposite end thereof. A first portion <NUM> of the base section <NUM> extends into the wall <NUM>. A second portion <NUM> of the base section <NUM>, which is opposite the first portion <NUM>, is adjacent the product flow channel <NUM> and thereby being in direct contact with the product flow channel <NUM>. The stem <NUM> is configured to be introduced through the void space <NUM>. In other words, the void space <NUM> has the shape of a truncated, hollow cylinder, where the rotatable stem <NUM> extends through a hollow section <NUM> of the void space <NUM>.

When the stem <NUM> is introduced through the wall <NUM> of the valve body <NUM> and the stem holder is arranged to hold the stem <NUM> in the desired way, in relation to the valve body <NUM>, the peripheral part 225a, seen along an axial direction STE, of the stem seal <NUM> faces the base section <NUM> partially defining the void space <NUM>. Once the peripheral part 225a of the stem seal <NUM> faces the base section <NUM>, the stem seal <NUM> is defining a ring-shaped area <NUM> partially defining the void space <NUM> at which the sealing between the stem holder <NUM> and the valve body <NUM> is provided. Thereby, the stem seal <NUM> is fluidly connected with the product flow channel <NUM>.

As mentioned, the void space <NUM> should be understood as a geometrical shape that defines its surrounding, i.e. it is a technical design parameter that gives the valve certain technical characteristics. The void space <NUM> is therefore created to let its geometrical shape define the shape of the parts of the valve that surround the void space. It can therefore be said the shape of the various valve parts define the shape of the void space <NUM>. More particularly, the shapes of the housing <NUM>, the stem <NUM>, the stem seal <NUM> and the product flow channel <NUM> define the shape of the void space <NUM> (or vice versa).

With reference to <FIG>, showing section <NUM> of <FIG>, the main sealing element <NUM> and the disk <NUM>, when in the closed position P1, is illustrated in further detail. Herein, the disk <NUM> abuts the main sealing element <NUM> thereby providing the sealing such that no product may pass the disk <NUM>. There is a gap <NUM> formed between the main sealing element <NUM> and the main sealing groove <NUM>, thereby the main sealing element <NUM> may be able to be pressed towards the main sealing groove <NUM> once the disk <NUM> abuts the main sealing element <NUM>. This is advantageous in that a reduced wear and tear is provided on the main sealing element <NUM> compared to conventional valves. Thereby, an increased gasket replacement interval is facilitated. The leakage passage 218b as discussed above is also illustrated in further detail.

<FIG> is a flowchart illustrating a method <NUM> for mixing a liquid food product with a powder food product. The method <NUM> comprises a first step S702 in which the liquid food product is fed to the tank <NUM> of the mixing unit <NUM> as discussed in connection with <FIG>. The liquid food product has a liquid surface LS inside the tank <NUM>. Thereafter, in a second step S704, a vacuum is applied to the tank <NUM> by using the vacuum source <NUM> of the mixing unit <NUM>. In a third step S706, powder food product is feed to the tank of the mixing unit <NUM> via the valve <NUM> as discussed above. It should be noted that the liquid surface LS is preferably above the powder inlet <NUM> such that the powder food product is fed to the tank <NUM> below the liquid surface LS. In a fourth step S708, the liquid food product is agitated with the powder food product by using the agitator <NUM> of the mixer.

Even though illustrated and described in a certain order, other orders may also be used.

Claim 1:
A valve (<NUM>) for controlling a product flow, the valve (<NUM>) comprising
a valve body (<NUM>) having a product inlet (<NUM>), a product outlet (<NUM>), a product flow channel (<NUM>) formed between the product inlet (<NUM>) and the product outlet (<NUM>), and a valve seat (<NUM>) arranged in the product flow channel (<NUM>),
a rotatable stem (<NUM>) extending through a wall (<NUM>) of the valve body (<NUM>) and into the product flow channel (<NUM>) with an end portion (221a) of the stem (<NUM>) disposed within the product flow channel (<NUM>),
a disk (<NUM>) arranged at the end portion (221a) of the stem (<NUM>) at an angle (α) greater than zero relative to an elongated extension (STE) of the stem (<NUM>), the disk (<NUM>) being movable from a closed position (P1) where it abuts the valve seat (<NUM>) for sealing the product flow channel (<NUM>), to an open position (P2) by rotating the stem (<NUM>) approximately <NUM>°,
wherein the valve body (<NUM>) comprises a stem seal groove (<NUM>) having a stem seal (<NUM>) that surrounds the stem (<NUM>) for providing sealing between the valve body (<NUM>) and the stem (<NUM>),
a void space (<NUM>) surrounding the stem (<NUM>) and extending from the stem seal (<NUM>) to the product flow channel (<NUM>), such that the stem seal (<NUM>) is fluidly connected to the product flow channel (<NUM>) via the void space (<NUM>),
characterized in that the void space (<NUM>) has, in a radial direction (R) of the stem (<NUM>), an extension (VE) that has a length that is at least <NUM>% of a thickness (DM) of the stem (<NUM>), where the thickness (DM) of the stem (<NUM>) is measured across the stem (<NUM>) in the radial direction (R), the extension (VE) being be measured on a side of the stem (<NUM>) that is opposite the product flow channel (<NUM>).