TECHNICAL FIELD The disclosure relates to a plant for ultra-high temperature treatment (UHT) of heat-sensitive fluid foodstuffs, such as whey protein concentrate, baby food, nutritious drinks and cheese milk, the plant comprising an infusion chamber in which the fluid is heat treated by way of supply of steam.

BACKGROUND

EP 0 794 706 discloses an infusion plant for high temperature treatment heat-sensitive fluid foodstuffs, such as whey protein concentrate and cheese milk. The plant has an infusion chamber, in which the fluid is subjected to a heat treatment by feeding steam. The food product is introduced at the top of the infusion chamber as a bundle of separate and mainly downwardly directed jets of foodstuff. The lower section of the infusion chamber serves to collect the foodstuff and has cooled walls using a cooling jacket. An outlet opening of the infusion chamber is arranged at the bottom of the infusion chamber and the outlet opening is connected to the inlet of a positive-displacement pump. The outlet of the positive-displacement pump is connected to the inlet of a vacuum chamber that serves to remove water from the food product that was added during the steam infusion.

The infusion plant uses high temperature for a short time to kill micro-organisms by steam infusion. This technology is widely used in the dairy industry where products can lose their nutritional value, flavor and

02187-PCT-II appearance as micro-organisms multiply. These organisms thrive at certain temperatures but if they are not present in a product, the product can be stored for many months without the need for refrigeration. Steam infusion achieves this objective with minimal heat degradation compared with other UHT processes. It helps protect essential components such as vitamins and results in fresh tasting products with outstanding quality. It provides the necessary kill rate for commercial sterility and can handle a wide product viscosity range - covering fluids from milk, puddings, ice cream, baby food, condensed milk, processed cheese, sauces and creams to lotions . In the known infusion plant a cooling jacket is provided around the bottom section of the infusion chamber for minimizing burn-on and fouling. However, fouling is not completely prevented and cleaning and/or rinsing of the infusion chamber is necessary after a given period of operation, depending e.g. on the type of foodstuff. It is though desirable to minimize fouling and to obtain longer running times between cleaning operations and thereby achieve better production efficiency. Also, a more predictable length of run time before cleaning is needed would be desirable. Overall, the market requests more efficient bacteria killing equipment to meet the increasingly demand to produce heat sensitive products like baby foods. SUMMARY

It is an object of the invention to provide an infusion plant for ultra-high treatment of fluid foodstuffs with

02187-PCT-II longer and/or more predictable running time between cleaning operations necessitated by fouling or burn-on.

This object is achieved according to a first aspect of the invention by providing a plant for heat treating heat- sensitive fluid foodstuffs, such as whey protein concentrate, baby food, baby food liquid concentrates, nutritious drinks or cheese milk, the plant comprising: an infusion chamber, in which the fluid foodstuff is subjected to a heat treatment by a feeding of steam, a fluid foodstuff inlet connected to a plurality of openings at the top of the infusion chamber for creating a plurality of essentially downwardly directed separate fluid foodstuff jets, the infusion chamber having a bottom section configured to collect the fluid foodstuff from the fluid foodstuff jets, the bottom section having an outlet opening at the bottom of the infusion chamber for allowing the collected fluid foodstuff to exit the infusion chamber, the outlet opening being seamlessly connected to the inlet of a pump, and a cooling jacket surrounding the bottom section for cooling the bottom section, the cooling jacket extending all the way down to the pump . By providing a seamless transition between the bottom section and the pump and by providing cooling around the bottom section and all the way down to the pump fouling and burn-on is reduced and results in longer and safer production time between cleanings, which significantly increases production efficiency of the infusion heat treatment plant.

02187-PCT-II In a first possible implementation form of the first aspect the pump comprises a pump housing and the cooling jacket extends into the pump housing. In a second possible implementation form of the first aspect the outlet is an integral part of the bottom section and the pump housing is integral with the outlet in order to obtain a seamless transition from the bottom section to the pump.

In a third possible implementation form of the first aspect the outlet of the bottom section is welded directly to the inlet of the pump housing to form a seamless transition.

In a fourth possible implementation form of the first aspect the bottom section has steel walls that are welded to an upwardly projecting flange or ridge of the pump housing .

In a fifth possible implementation form of the first aspect the plant further comprising a feed conduit for feeding cooling fluid to the cooling jacket and a return conduit for returning cooling fluid from the cooling jacket, a portion of the feed conduit extending through the pump housing and connecting to the cooling jacket at a location inside the pump housing.

In a sixth possible implementation form of the first aspect the pump is a positive displacement pump, preferably a gear pump or a lobe pump.

In a seventh possible implementation form of the first aspect the pump is a centrifugal pump.

02187-PCT-II In an eighth possible implementation form of the first aspect the bottom section is releasably connected to the upper section, e.g. by a flanged connection.

The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present disclosure, the invention will be explained in more detail with reference to the example embodiments shown in the drawings, in which:

Fig. 1 is a diagrammatic view of an ultra-high temperature treatment plant,

Fig. 2 is a sectional view of an infusion plant according to an example embodiment,

Fig. 3 is an initial image taken by a camera of the infusion plant of Fig. 2,

Fig. 4 is an image taken by a camera of the infusion plant of Fig. 2 after a running time, and

Fig. 5 is a flow chart illustrating an example embodiment of a method for using an optical digital camera with an infusion plant. DETAILED DESCRIPTION

Fig. 1 discloses a plant for ultra-high temperature treatment of liquid foodstuff. The liquid foodstuff can be any foodstuff in liquid form, but the disclosed plant is

02187-PCT-II particularly useful for temperature sensitive foodstuffs that should be heated for killing bacteria for a short period only so as to preserve their flavor, consistency and nutritious qualities. Examples of such liquid foodstuffs are milk, baby food liquid, baby food liquid concentrate or nutritional drinks (with high protein content) . The liquid foodstuff may have a high dry matter content (40% and higher) and/or high protein content (6% or higher) .

The plant of Fig. 1 has an infusion chamber 1 of a conventionally known type. The infusion chamber 1 is connected to a tube 2 for feeding fluid foodstuff to be heat treated inside the infusion chamber 1, and a tube 3 for the feeding of steam. Finally, the infusion chamber is connected to tubes 4 and 5 for feeding and removing liquid for cooling the bottom of the infusion chamber 1. In an embodiment the cooling liquid is water. The outlet of the infusion chamber 1 directly connected with a pump 6. In an embodiment the pump 6 is a centrifugal pump. In another embodiment the pump 6 is a positive displacement pump, such as a lobe or gear pump. The outlet of the pump 6 is connected to the inlet of a vacuum chamber 10 of a conventionally known type through a tube 9. This vacuum chamber is adapted to remove the amount of water being supplied in form of steam in the infusion chamber through a tube 11, whereas the concentrated fluid foodstuff is drained off through a tube 12 and a pump 13 in a conventionally known manner.

Fig. 2 is a diagrammatic sectional view of the infusion chamber. The infusion chamber is preferably essentially rotation symmetrical around a vertical axis. The upper section 30 of the infusion chamber has a hollow

02187-PCT-II cylindrical part and a top part that is shaped similar to a conical frustum. A bottom section 32 is releasably connected to the upper section 30 by a flanged connection 34 for allowing access to the interior of the infusion chamber 1 for cleaning and/or maintenance. The bottom section 32 has in an embodiment a shape similar to a conical frustum. At the lower end of the infusion chamber there is an outlet opening 19 that is directly connected to the inlet of a lobe pump 6.

The fluid foodstuff to be treated is carried through the tube 2 into the infusion chamber 1. The fluid foodstuff enters the infusion chamber 1 as a bundle 7 of separate liquid foodstuff jets through a plurality of openings in a nozzle at the top of the infusion chamber 1. Hot steam is injected into the infusion chamber 1 through a circumferential steam distribution chamber in a well- known manner. In the infusion chamber 1 the liquid foodstuff jets meet the hot steam and the foodstuff is thereby heated and absorbs the steam.

The liquid foodstuff jets end on the funnel shaped inner wall of the bottom section 32. The bottom section 32 collects the liquid foodstuff from the liquid foodstuff jets and guides it to the outlet opening 19 at the lower end of the infusion chamber 1 (which is also the lower end of the bottom section 32 and which is also the inlet of the pump 6) . A cooling jacket 15 is provided around the bottom section 32. The cooling jacket 15 keeps the bottom section 32 cool, to prevent or minimize the liquid foodstuff that gets into contact with the inner walls of the bottom section 32 to foul or burn-on. The cooling jacket 15

02187-PCT-II provides for a mantle of cooling water or other cooling medium around the bottom section 32. The mantle is divided by a spiral traverse wall 17 that guides the cooling water in a spiral pattern around the bottom section 32. The inlet of the cooling water 4 passes though the pump housing and into a portion 29 of the mantle that extends also into the pump housing. From the portion 29 internal to the pump housing the spiral path of the cooling water continues spirally upwards towards the cooling medium outlet 5 at the top of the cooling jacket 15 and near the top of the bottom section 32.

The lower portion of the bottom section 32 forms the outlet opening 19 of the chamber that connects seamlessly to the inlet of the pump 6. This is in an embodiment achieved by the lower end of the bottom section 32 being made from steel plates, preferably stainless steel, and connected to the pump housing by welds 18. In an embodiment the pump housing is provided with a circular ridge or circular upright flange that facilitates welding of the pump housing to the lower end of the bottom section 32. After welding the transition between the bottom section 32 and the pump housing/pump inlet formed by the welds 18 is machined to provide a perfectly smooth surface without and cracks or fissures that could be difficult to clean or rinse.

The gear or lobe pump 6 is of a conventionally known type and is connected to the outlet 19 of the infusion chamber 1, and the housing of the gear or lobe pump 6 is provided with a temperature sensor 16 at a location where the adjacent surface is kept clean of burnings by means of the teeth of the gear wheels or by the lobes of the

02187-PCT-II rotors 8. In this manner it is possible to ensure a reliable control of the plant.

In an example embodiment an optical camera 20, preferably a digital optical camera) is mounted on the infusion chamber 1 with an angle of view 21 covering at least a portion of the bottom section 32 so that an operator or a processor configured therefore can determine that fouling has occurred (or not) and cleaning needs to be performed (or not) . The optical camera 20 is preferably mounted at or near top of the infusion chamber 1, pointing downwards towards the bottom section 32. The wall of the infusion chamber is in an embodiment provided with a sight glass 23 for allowing the optical camera 20 to view into the infusion chamber 1.

The sight glass 23 is preferably at least on its inner side facing the interior of the infusion chamber 1 provided with a coating to prevent formation of water droplets on the inner side.

In an embodiment, images from the optical camera 20 are processed by a processor (not shown) that is configured to detect changes in the image. The processor is further configured to issue a notification or alarm when it has determined that the image taken by the camera 20 has changed relative to an initial image taken shortly after the start of a production run. Another optical camera 25 (preferably a digital optical camera) is mounted on the infusion chamber 1 with an angle of view 26 covering at least a portion of the bundle 7 of fluid foodstuff jets.

02187-PCT-II The optical camera 25 can be mounted at or near the bottom of the infusion chamber 1, pointing upwards towards the upper section 30. The invention has been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word

"comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The reference signs used in the claims shall not be construed as limiting the scope. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. The reference signs used in the claims shall not be construed as limiting the scope.

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