Patent Description:
Product powders may be used to produce various food products. Using product powders are advantageous in that the powder may be stored for long periods of time without being spoiled. The powder may also be easily dissolved in a liquid to form the desired product. Food products formed by powders may include dairy beverages, such as milk, non-dairy beverages, such as soft drinks, and other dairy products such as ice cream, yogurt, or cheese. Product powders may include raw materials such as sugar, milk powder, salt, or flour, or finished products such as instant formula, instant drinks, or dry broth. In producing a milk alternative that resembles fresh dairy milk, raw milk powder may be used. The raw milk powder dissolves easily in water to form a reconstituted liquid milk that undergoes further processing, including filtration, homogenization, and heat treatment, to form the final beverage product. Other form of food product powders are such ingredients that are mixed together to form bake mixtures and cake mixtures.

Product powders may require a mixing process which often occurs in a sealable container including a stirring arrangement, paddle mixers, or other suitable mixing devices. After mixing and emptying the product mixture from the sealable container, a residual powder may remain on the interior walls of the sealable container. A conventional method for cleaning the interior walls includes maintenance personnel manually removing the powder using industrial vacuum cleaners. The conventional cleaning method is deficient in that the cleaning process is labor-intensive. The conventional cleaning method may also require opening the container causing the container interior to be susceptible to contamination.

Apparatuses for handling powder, some of which describe cleaning, are disclosed in patent documents <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT>. An apparatus for the mixing of bulk material which comprises a cleaning system is described in <CIT>. However, few if any of these documents relate to powders that are used to produce food products.

It is an object of the invention to at least partly overcome one or more limitations of the prior art. In particular, it is an object to provide a device and method that accomplish efficient cleaning of an apparatus for handling a food product powder.

According to an aspect of the invention, an apparatus according to claim <NUM> is provided for handling a food product powder.

The apparatus includes a sealable container having an interior surface defining a volume in which the food product powder is handled, and a powder outlet, and a nozzle arrangement that is attached to the container and configured to feed air into the container. The nozzle arrangement includes a plurality of jet nozzles configured to direct the air towards the interior surface to remove product powder from the interior surface, such that the air and the removed product powder may flow out of the container via the powder outlet. Said apparatus is characterized in that it is a mixing apparatus that comprises at least one rotatable stirring device for the food product powder, the jet nozzles are arranged to ensure coverage of an entire area of the interior surface, such that the product powder may be removed from the entire surface area of the interior surface, and the interior surface area includes the area of the rotatable stirring device.

Accordingly, the cleaning according to the invention is not done in the traditional way, i.e. by opening the container and manually using a vacuum cleaner to remove the powder from the interior surface and out of the container. Instead, the powder is removed from the interior surface using the jet nozzles that direct the air towards the interior surface, and the removed powder and air may be drawn out of the container. The apparatus for handling a food product powder described herein is advantageous in that the apparatus enables cleaning in a very efficient and sanitary manner. The container may remain closed during the cleaning process. The apparatus includes multiple sets of jet nozzles that are arranged to direct the flow of air towards different walls of the container, and the jet nozzles may be arranged to have a predetermined impact angle of the flow of air hitting the respective surface. The arrangement of the jet nozzles is advantageous in ensuring that the powder is removed from the respective surface such that it may be drawn out of the container.

According to another aspect of the invention, a method for cleaning according to claim <NUM> is used for an apparatus for handling a food product powder that includes a sealable container having an interior surface defining a volume in which the food product powder is handled, and a powder outlet, the apparatus being a mixing apparatus that comprises at least one rotatable stirring device for the food product powder,.

The method includes feeding air into the container using a nozzle arrangement that is attached to the container, wherein the air is directed by a plurality of jet nozzles towards the interior surface to remove product powder from the interior surface, and drawing air out from the container, such that air and the removed product powder may flow out of the container via the powder outlet. Said method is characterized in having the jet nozzles arranged to ensure coverage of an entire area of the interior surface, such that the product powder may be removed from the entire surface area of the interior surface, and the interior surface area including the area of the rotatable stirring device.

This method may include the same features as the apparatus for handling a food product powder and shares the same advantages.

Features of the invention will now be described, by way of example, with reference to the accompanying schematic drawings.

Embodiments of the invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments of the invention are shown. The invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Referring first to <FIG>, an apparatus <NUM> for handling a food product powder is shown. The apparatus <NUM> includes a sealable container <NUM> having an interior surface <NUM> that defines a volume <NUM> in which the food product powder is handled, and a powder outlet <NUM>. The apparatus <NUM> may be oriented horizontally such that the powder outlet <NUM> is arranged at a bottom of the apparatus <NUM>. A nozzle arrangement <NUM> is attached to the container <NUM> and is configured to feed air into the container <NUM> for removing residual food product powder from the container <NUM> during a cleaning process that occurs after as much as possible of the food product powder has been removed from the container <NUM> for packaging or further processing. The nozzle arrangement <NUM> includes a plurality of jet nozzles <NUM>, <NUM>, <NUM> that are configured to direct the air towards the interior surface <NUM> to remove the product powder from the interior surface <NUM>. After the product powder is removed from the interior surface <NUM>, the air and the removed product powder exit the container <NUM> via the powder outlet <NUM>.

Referring in addition to <FIG>, handling the food product powder in the container <NUM> may include stirring or mixing the food product powder to produce the food product. <FIG> shows an exemplary mixing arrangement for the apparatus <NUM>. The food product may be a beverage product, such as a dairy beverage or a non-dairy beverage. The beverage product may include milk or soft drinks. The food product may include other non-beverage food products such as ice cream, yogurt, or cheese. The product powder may include any suitable ingredient to form the desired food product. The product powder may include raw materials such as sugar, milk powder salt, or flour, or finished product such as instant formula, instant drinks, or dry broth. Other product powders may be suitable. The apparatus <NUM> may not necessarily be used to stir or mix the food product powder. For example, the apparatus <NUM> may be used to transport the product powder and the nozzle arrangement <NUM> may be used for cleaning the apparatus <NUM> after the product powder is removed from the container <NUM>.

The interior surface <NUM> of the container <NUM> is defined by a first side wall <NUM>, a second side wall <NUM> that is opposite the first side wall <NUM>, and a back wall <NUM> of the container <NUM> that extends between the first side wall <NUM> and the second side wall <NUM>. As shown in <FIG>, a front wall <NUM> is arranged opposite the back wall <NUM>. The front wall <NUM> may be formed as a pivotable door for the container <NUM> and may be attached to the container <NUM> via handles and hinges <NUM>. A top surface or ceiling <NUM> extends between the first side wall <NUM> and the second side wall <NUM>, and between the back wall <NUM> and the front wall <NUM>. The side walls <NUM>, <NUM> may be angled relative to the ceiling <NUM> that extends horizontally. The container <NUM> and the interior surface <NUM> may have any suitable shape and the shape may be dependent on the application, such as whether the container <NUM> is used for housing a mixing or stirring arrangement, or for transport.

As shown in <FIG>, a rotatable stirring device <NUM>, <NUM> for stirring or mixing the product powder may be mounted to the back wall <NUM> and extend through the volume <NUM> of the container <NUM> when the apparatus <NUM> is assembled. The rotatable stirring device <NUM>, <NUM> may include a first rotatable shaft <NUM> and a second rotatable shaft <NUM> that each includes mixing paddles <NUM>. The rotatable shafts <NUM>, <NUM> rotate in same or in an opposite rotational direction relative to each other during mixing of the product powder. The shape of the container <NUM> may be formed to accommodate rotation of the first rotatable shaft <NUM> and the second rotatable shaft <NUM>. The side walls <NUM>, <NUM> of the container <NUM> may each be formed to have a concave shape on their interior sides at the bottom of the container <NUM> such that each of the rotatable shafts <NUM>, <NUM> are accommodated in a circular cavity 2a, 2b of the container <NUM>. Other shapes may be suitable for the container <NUM>. An engine <NUM> is arranged outside the container <NUM> and is coupled to the rotatable stirring device <NUM>, <NUM> for rotation thereof. Any suitable engine or drive mechanism may be provided.

The nozzle arrangement <NUM> includes a plurality of sets of jet nozzles <NUM>, <NUM>, <NUM> that are mounted to the container <NUM> and arranged to direct a flow of air towards the interior surface <NUM>. The distribution of the sets of jet nozzles <NUM>, <NUM>, <NUM> in the nozzle arrangement <NUM> is dependent on the shape of the container <NUM>. The sets of jet nozzles <NUM>, <NUM>, <NUM> are arranged to ensure coverage of an entire area of the interior surface <NUM>, meaning that product powder may be removed from the entire surface area of the interior surface <NUM>. The sets of jet nozzles <NUM>, <NUM>, <NUM> may have an unsymmetrical distribution along the interior surface <NUM> of the container <NUM> and each jet nozzle in the sets of jet nozzles <NUM>, <NUM>, <NUM> may be arranged tangentially relative to a respective wall <NUM>, <NUM>, <NUM>, <NUM>. Each set of jet nozzles <NUM>, <NUM>, <NUM> may correspond to a different wall <NUM>, <NUM>, <NUM>, <NUM> for directing air at the respective wall <NUM>, <NUM>, <NUM>, <NUM>. Jet nozzles within a single set may be evenly spaced and mounted in a similar orientation relative to the same wall <NUM>, <NUM>, <NUM>, <NUM>.

Three different sets of jet nozzles <NUM>, <NUM>, <NUM> are shown in <FIG>. A first set of jet nozzles <NUM> includes jet nozzles <NUM>, <NUM> that are arranged to direct a flow of air towards the side walls <NUM>, <NUM>. The jet nozzles <NUM>, <NUM> may be evenly spaced and are angled relative to the respective side wall <NUM>, <NUM>. The jet nozzles <NUM> correspond to the first side wall <NUM> and the jet nozzles <NUM> correspond to the second side wall <NUM>. Any suitable number of jet nozzles <NUM>, <NUM> may be used, such as three or more jet nozzles per side wall <NUM>, <NUM>. Each side wall <NUM>, <NUM> may have four jet nozzles that are arranged at an upper location along the respective side wall <NUM>, <NUM> and configured to direct air at the respective wall <NUM>, <NUM>. The jet nozzles <NUM> corresponding to the first side wall <NUM> may have the same orientation and angle relative to the first side wall <NUM>. Similarly, the jet nozzles <NUM> corresponding to the second side wall <NUM> may have the same orientation and angle relative to the second side wall <NUM>. The jet nozzles <NUM> and the jet nozzles <NUM> may be symmetrically arranged relative to each other to direct air flow downwardly along the respective side wall <NUM>, <NUM> for powder removal therefrom.

A second set of jet nozzles <NUM> includes jet nozzles <NUM>, <NUM> that are arranged to direct a flow of air towards the ceiling <NUM> for removing product powder therefrom. The second set of jet nozzles <NUM>, <NUM> may be arranged perpendicular relative to the first set of jet nozzles <NUM>, <NUM> such that the second set of jet nozzles <NUM>, <NUM> are arranged along a line that is parallel with the back wall <NUM> and the front wall <NUM> whereas the first set of jet nozzles <NUM>, <NUM> are arranged along a line that is parallel with the side walls <NUM>, <NUM>. The jet nozzles <NUM> are arranged proximate the back wall <NUM> and the jet nozzles <NUM> are arranged opposite the jet nozzles <NUM> and proximate the front wall <NUM> (shown in <FIG>). The jet nozzles <NUM> and the jet nozzles <NUM> may be symmetrically arranged relative to each other such that each set of jet nozzles <NUM>, <NUM> directs air flow along the ceiling <NUM> towards the opposite set of jet nozzles <NUM>, <NUM>. Any suitable number of jet nozzles <NUM>, <NUM> may be used, such as three or more jet nozzles. Four jet nozzles may be arranged proximate each of the back wall <NUM> and the front wall <NUM>.

A third set of jet nozzles <NUM> includes jet nozzles <NUM>, <NUM> that are arranged to direct a flow of air towards a center of the container <NUM> or any other common location for collection of the removed powder. The jet nozzles <NUM>, <NUM> may be angled away from the ceiling <NUM> and the side walls <NUM>, <NUM> to direct airflow that moves the removed powder from the ceiling and the side walls <NUM>, <NUM> toward the center of the container <NUM>, such that the air and the powder may be drawn out of the container from the powder outlet <NUM>. The jet nozzles <NUM> may be arranged proximate the first side wall <NUM> and the jet nozzles <NUM> may be arranged proximate the second side wall <NUM>. The jet nozzles <NUM>, <NUM> may be symmetrically arranged relative to each other. Any suitable number of jet nozzles <NUM>, <NUM> may be used. Three jet nozzles may be arranged proximate each of the side walls <NUM>, <NUM>.

The first, second, and third sets of jet nozzles <NUM>, <NUM>, <NUM> may be operated at different times and different jet nozzles within a set may also be operated at different times. Operation of each jet nozzle in the nozzle arrangement <NUM> may be controlled using a control valve <NUM> for each jet nozzle that independently controls the air passing through the respective jet nozzle. The control valves <NUM> may include any suitable activation device, such as a solenoid. Each control valve <NUM> is fluidly connected to a source of pressurized air (not shown) via a supply line <NUM>. The source of pressurized air is connected to the supply line <NUM> via an air supply pipe (not shown). The supplied air may be filtered, sterilized, or dried and the source may be a compressor. The amount of air pressure in the supply line <NUM> may be maintained at a constant value.

During the cleaning process, the control valves <NUM> corresponding to the first and second sets of jet nozzles <NUM>, <NUM> may first be opened to direct air flow at the ceiling <NUM> and the side walls <NUM>, <NUM> to remove the powder. After the product powder is removed from the interior surface <NUM>, the first and second sets of jet nozzles <NUM>, <NUM> may be closed and the control valves <NUM> corresponding to the third set of jet nozzles <NUM> may be opened to direct the removed powder and the air toward the center of the container <NUM>. Suction from a vacuum pump <NUM> (schematically shown in <FIG>) that is connected to the powder outlet <NUM> may be used to draw the removed powder and the air out of the container <NUM> through the powder outlet <NUM>. The powder outlet <NUM> may be opened and closed via a valve located in a passage of the powder outlet. This valve is operable by an actuator <NUM> that is configured to open and close the valve.

Referring now to <FIG>, a front sectional view of the apparatus <NUM> including the nozzle arrangement <NUM> and the rotatable stirring device <NUM>, <NUM> is shown. <FIG> shows pipes <NUM> that are configured for both supplying air to the corresponding jet nozzle and for mounting each jet nozzle <NUM>, <NUM>, <NUM> to the container <NUM>. The pipes <NUM> may be welded to the periphery of the container <NUM> and extend into the volume <NUM> to hold the jet nozzles <NUM>, <NUM>, <NUM> within the container <NUM>. Each pipe <NUM> is fluidly connected to a respective control valve <NUM> and to the supply line <NUM> shown in <FIG>. The supply line <NUM> may also be formed of piping that branches through the container <NUM>. The nozzle arrangement <NUM> may be secured to the container <NUM> using any other suitable mounts, brackets, clamps, hooks, bolts, screws, and the like.

Each jet nozzle <NUM>, <NUM>, <NUM> is arranged to direct the flow of air at the respective surface such that the flow of air impacts the surface at a predetermined impact angle. The first set of jet nozzles <NUM> that correspond to the side walls <NUM>, <NUM> includes jet nozzles that are arranged to direct the flow of air towards the first or second side wall <NUM>, <NUM> at an impact angle θ<NUM> that is between <NUM> and <NUM> degrees relative to the respective side wall <NUM>, <NUM>. The impact angle θ<NUM> may be between <NUM> and <NUM> degrees, or between <NUM> and <NUM> degrees. The impact angle θ<NUM> may be defined as the angle between the flow direction F of the air and the tangential direction T of the surface at the point of impact <NUM> of the air flow. The point of impact <NUM> of the air flow on the respective side wall <NUM>, <NUM> may be between <NUM> and <NUM> centimeters from the outlet of the jet nozzle <NUM>, or even outside this range. As also shown in <FIG>, the third set of jet nozzles <NUM> are angled away from the walls <NUM>, <NUM> to direct the flow of air towards a horizontal center-plane C of the container <NUM>. The center plane C may be defined as a horizontal plane that divides the volume <NUM> into two volumes of equal size.

Referring now to <FIG>, a side view of the apparatus <NUM> is shown. The pipes <NUM> for the second set of jet nozzles <NUM> may alternatively as illustrated in <FIG> be attached to the back wall <NUM> or the front wall <NUM>. The second set of jet nozzles <NUM> are arranged to direct the flow of air towards the ceiling <NUM>. The impact angle θ<NUM> of the flow of air hitting the ceiling <NUM> is between <NUM> and <NUM> degrees relative to the ceiling <NUM>. The impact angle θ<NUM> may be between <NUM> and <NUM> degrees, or even between <NUM> and <NUM> degrees. The point of impact <NUM> of the air flow on the ceiling <NUM> may be between <NUM> and <NUM> centimeters from the outlet of the jet nozzle <NUM>, or may even be outside this range. As best shown in <FIG>, each of the jet nozzles <NUM>, <NUM>, <NUM> may include a flat fan nozzle having a fan-shaped outlet <NUM> that is configured to eject the air in a fan-shaped air flow pattern across the corresponding surface. Other types of nozzles may be suitable and the different sets of jet nozzles <NUM>, <NUM>, <NUM> may have the same or types of nozzles.

Referring now to <FIG>, an air flow path in the container <NUM> of the apparatus <NUM> is shown. The air flow path may be continuous around the interior surface <NUM>. Air may be fed to the sets of jet nozzles <NUM>, <NUM>, <NUM> at any suitable flow rate. Feeding the air may occur at a flow rate that is between <NUM> and <NUM> normal cubic meters per hour (Nm<NUM>/h) per square meter of the area of the interior surface <NUM> of the container <NUM>. A "normal cubic meter" means one cubic meter of air at a temperature of zero degrees at a pressure of <NUM> bar. Feeding the air may also occur at a flow rate that is between <NUM> and <NUM> cubic meters per hour, where the air has the same temperature and pressure as the air surrounding the apparatus <NUM>. The interior surface area may include the area of the rotatable stirring device <NUM>, <NUM> (shown in <FIG> and <FIG>) or any other mixing device arranged in the container <NUM>. Feeding the air may include varying the air flow through at least one of the jet nozzles <NUM>, <NUM>, <NUM> to temporarily increase the air flow through the corresponding jet nozzle <NUM>, <NUM>, <NUM>, such that the air supply is pulsated. The flow rate during feeding is dependent on the application and in exemplary applications, feeding the air may occur at a flow rate that is between <NUM> and <NUM><NUM>/h, or between <NUM> and <NUM><NUM>/h (surrounding temperature and pressure). Feeding the air to the jet nozzles <NUM>, <NUM>, <NUM> may include feeding the air with a flow rate that provides a velocity of the air that is at least <NUM> meters per second (m/s) at the point of impact <NUM>.

Air may be drawn from the container <NUM> at any suitable flow rate. Drawing the air from the container <NUM> may occur at a flow rate that is between <NUM> and <NUM><NUM>/h, or between <NUM> and <NUM><NUM>/h (surrounding temperature and pressure), per square meter of the area of the interior surface <NUM> of the container <NUM>. The flow rate during drawing is dependent on the application and in exemplary applications, drawing the air may occur at a flow rate that is between <NUM> and <NUM><NUM>/h, or between <NUM> and <NUM><NUM>/h (surrounding temperature and pressure).

As shown in <FIG>, the first set of jet nozzles <NUM> may be configured to direct a flow of air <NUM> downwardly along the side walls <NUM>, <NUM>. The shape of the container <NUM> may force the air to flow concavely upwardly from a bottom of the container <NUM> toward the horizontal center-plane C. The second set of jet nozzles <NUM> may be configured to direct a flow of air <NUM> along the ceiling <NUM>. The flow of air <NUM> may be directed from the back of the container <NUM> toward the front of the container <NUM> or vice versa, such that the air hits the front and back walls <NUM>, <NUM> (shown in <FIG>) after the air passes the ceiling <NUM>. The third set of jet nozzles <NUM> are configured to direct a flow of air <NUM> toward the horizontal center-plane C of the container <NUM>. The nozzles may be operated intermittent so that no air flows collides and interfere with each other.

<FIG> shows an exemplary control system <NUM> for the apparatus <NUM>. The cleaning process may be automated using the control system <NUM> which includes a processor <NUM> that is communicatively coupled with the control valves <NUM> for activation of the control valves <NUM>, and a pneumatic conveying system <NUM> that is configured to supply air to the nozzle arrangement <NUM>. The control valves <NUM> may be solenoid valves and the processor <NUM> may include any suitable processors and electronic control mechanisms, such as, for example, a central processing unit (CPU), a microprocessor, control circuitry, and the like.

The pneumatic conveying system <NUM> may include a compressor and the control system <NUM> may control the compressor to feed the air to the supply line <NUM> at the predetermined flow rate, e.g. a flow rate that is between <NUM> and <NUM><NUM>/h. The control system <NUM> may be used to maintain constant pressure in the supply line <NUM>. The processor <NUM> may activate the jet nozzles <NUM>, <NUM>, <NUM> of the nozzle arrangement <NUM> sequentially, such that the feeding of air to the container <NUM> provides an air flow that varies over time through the jet nozzles. The control system <NUM> may also be used to vary the air flow through at least one of the jet nozzles to temporarily increase the air flow through the jet nozzle. Any specific sequence of air flow in the container <NUM> may be provided using the control system <NUM>. Pulsated air flow, alternating air flow speeds, and different flow rates for different jet nozzles may be provided.

The pneumatic conveying system <NUM> may also be fluidly connected to the vacuum pump <NUM> for creating a suction effect that draws the air and the powder out of the powder outlet <NUM> of the container <NUM> (shown in <FIG>). The vacuum pump <NUM> may be operable independently from the nozzle arrangement <NUM>. The container <NUM> may be enclosed such that air may only exit through the powder outlet <NUM>. If more air is drawn out of the container <NUM> than is being supplied to the container <NUM>, the container <NUM> may include another additional inlet valve <NUM> for supplying more air into the container <NUM>. The inlet valve <NUM> may be a one-way valve that enables air to unilaterally pass through the valve into the supply line <NUM> for the container <NUM>. The inlet valve <NUM> may be arranged as part of the container <NUM> or outside the container <NUM>. Any suitable sensor <NUM>, such as a pressure sensor for detecting pressure in the supply line <NUM>, may be a part of the apparatus <NUM> such that the processor <NUM> may activate the inlet valve <NUM> and the control valves <NUM> in response to the detected data by the sensor <NUM>. Alternatively, the inlet valve <NUM> is a regular, mechanical pressure (vacuum) relief valve.

Referring now to <FIG>, a method <NUM> for cleaning an apparatus for handling a food product powder is shown. The apparatus <NUM> shown in <FIG> and the control system <NUM> shown in <FIG> may be used to perform the method <NUM>. The method <NUM> includes a step <NUM> of feeding air into the container <NUM> using the nozzle arrangement <NUM> that is attached to the container <NUM>. The air is directed by a plurality of jet nozzles <NUM>, <NUM>, <NUM> towards the interior surface <NUM> to remove product powder from the interior surface <NUM>. Step <NUM> may include feeding the air into the container <NUM> with a flow rate of between <NUM> and <NUM><NUM>/h per m<NUM> of interior surface area of the container <NUM>, or with another flow rate as previously indicated. Step <NUM> may include feeding the air into the container <NUM> with a flow rate that provides a velocity of the air of at least <NUM>/s at a point of impact <NUM>, <NUM> of the air against the interior surface <NUM> of the container <NUM>. Step <NUM> may include varying the air flow through at least one of the jet nozzles <NUM>, <NUM>, <NUM> to thereby temporarily increase the air flow through at least one jet nozzle <NUM>, <NUM>, <NUM> and cause powder release from the interior surface <NUM>.

A step <NUM> of the method <NUM> includes activating the jet nozzles <NUM>, <NUM>, <NUM>. Step <NUM> may include activating the jet nozzles <NUM>, <NUM>, <NUM> sequentially, such that the feeding of air into the container <NUM> provides an air flow that varies over time through the jet nozzles <NUM>, <NUM>, <NUM>. Step <NUM> may include activating jet nozzles for powder removal and a step <NUM> may include activating jet nozzles for directing the removed powder to the center of the container <NUM>. During step <NUM>, the first set of jet nozzles <NUM> and the second set of jet nozzles <NUM> may be activated and during step <NUM>, the third set of jet nozzles <NUM> may be activated. The activation of the jet nozzles during either step <NUM> or during step <NUM> may also be activated sequentially.

A step <NUM> of the method <NUM> includes drawing air out from the container <NUM>, such that air and the removed product powder may flow out of the container <NUM> via the powder outlet <NUM>. Step <NUM> may include drawing the air from the container <NUM> at a flow rate of a <NUM>-<NUM><NUM>/h per m<NUM> volume defined by the interior surface <NUM> of the container <NUM>, or drawing air at another flow rate as previously indicated. The method <NUM> is a dry-cleaning method, i.e. no liquid is supplied into the sealable container <NUM> when the method is performed.

The apparatus <NUM> for handling a food product powder including the nozzle arrangement <NUM> is advantageous in providing more efficient cleaning of the apparatus. The jet nozzles in the nozzle arrangement are configured to direct a flow of air at an interior surface of the sealable container to remove the residual product powder from the interior surface. The removed product powder and the air may flow out of the container via the powder outlet and a vacuum pump, such that the manual cleaning process for the apparatus may be less intensive or eliminated. In addition to providing a more efficient cleaning process, using the nozzle arrangement advantageously enables a more sanitary cleaning process due to the container being able to remain sealed during the cleaning process.

Claim 1:
An apparatus (<NUM>) for handling a food product powder, the apparatus (<NUM>) comprising:
a sealable container (<NUM>) having an interior surface (<NUM>) defining a volume (<NUM>) in which the food product powder is handled, and a powder outlet (<NUM>); and
a nozzle arrangement (<NUM>) that is attached to the container (<NUM>) and configured to feed air into the container (<NUM>), wherein
the nozzle arrangement (<NUM>) comprises a plurality of jet nozzles (<NUM>, <NUM>, <NUM>) configured to direct the air towards the interior surface (<NUM>) to remove product powder from the interior surface (<NUM>), such that the air and the removed product powder may flow out of the container (<NUM>) via the powder outlet (<NUM>), characterized in that
the apparatus (<NUM>) is a mixing apparatus that comprises at least one rotatable stirring device (<NUM>, <NUM>) for the food product powder,
the jet nozzles (<NUM>, <NUM>, <NUM>) are arranged to ensure coverage of an entire area of the interior surface (<NUM>), such that product powder may be removed from the entire surface area of the interior surface (<NUM>), and
the interior surface area includes the area of the rotatable stirring device (<NUM>, <NUM>).