KR102319037B1 - Method and equipment for processing thermosensitive liquid food and centrifugal pump for this type of equipment - Google Patents

Abstract

The present invention relates to a method for treating a thermosensitive liquid food product (P) according to the preamble of claim 1, an equipment for carrying out the method, and a centrifugal pump for an installation of the above type, which, during processing of said food, comprises an injection container and the tendency of food contamination therefrom into the centrifugal pump is reduced, in particular the centrifugal pump has a significantly longer service life compared to centrifugal pumps hydraulically optimized according to the prior art. In the tube in this method, it is in particular the following processing steps (c) and (d): for liquid food (P), (c) the housing cover (8) of the pump housing (12) of the centrifugal pump (54) performing a third cooling (K3) in , the housing cover directly adjacent the outlet pipe (52) or the inlet connector (76); and (d) as part of the volume flow carried in the impeller 100 of the centrifugal pump 54 , which volume flow is configured to open towards the housing cover 8 of the centrifugal pump 54 , the housing of the centrifugal pump 54 . The pump housing 12 and through the rear impeller gap s1 provided between the rear wall 10 and the impeller 100 and the front impeller gap s2 provided between the housing cover 8 and the impeller 100 providing at least one planned flushing action of the impeller 100 , wherein the volume flow of the planned flushing action is up to several times greater than the unavoidable equalization flow within the pump housing 12 , which in each case is the minimum rear and front impeller This is due to the hydrodynamically optimized design of the centrifugal pump 54 with the gaps s1*, s2*, ensuring the mechanical function of the centrifugal pump 54 .

Description

Method and equipment for processing thermosensitive liquid food and centrifugal pump for this type of equipment

The present invention relates to a method and equipment for processing milk used to make thermosensitive liquid baby food concentrate, nutritious drink or cheese, wherein liquid food is directly heated with steam to form a sterile state in an injection container, and at a lower pressure. An amount of water corresponding to the amount of steam supplied previously is removed from the liquid food by the depressurization of The invention also relates to a centrifugal pump for such installations and an impeller for such a centrifugal pump.

A thermosensitive liquid food of the type described above contains a relatively high amount of protein, a lot of dry matter and little water; These foods may have a low, medium or high viscosity. The term "heat sensitivity" refers to the tendency of these foodstuffs to burn, i.e. the tendency to form deposits on the walls of the dosing vessel and the centrifugal pump carrying it under these conditions, preferably at temperatures in excess of 100°C. It should be understood that there is The formation of these deposits is also called product contamination. Contamination of the product reduces the service life or the operating time of the centrifugal pump, particularly the dosing vessel, and particularly between two cleaning cycles.

A particularly important area of the equipment for carrying out the method is the outlet and the bottom area of the filling container tapering downward into the delivery device, the delivery device between the outlet of the filling container and the vacuum chamber serving to depressurize the heated liquid food. is placed on the connecting line of The conveying device may be a displacement pump, for example a geared pump or a centrifugal pump. The delivery device is disposed at a distance from the injection vessel or directly at its outlet. Accumulation of heated liquid food in the bottom area of the filling container and in the connecting line to the conveying device is undesirable and leads to an unspecified residence time. Sumps of heated liquid food should be avoided, especially in filling containers. Accordingly, there have been sufficient proposals for solving these shortcomings.

In the case of heating installations having an injection container, it is known to discharge the heated liquid food directly out of the injection container by means of a rotary displacement pump, for example a gear-type pump, the housing of the pump being provided with a cooling device, the housing comprising: It is connected directly to the outlet of the injection vessel (EP 0 784 706 B1). Geared pumps are inherently self-cleaning by design, as the gear wheels mesh closely together and sweep along the walls of the associated housing, preventing the build-up of an ever-growing deposit (contamination of the product).

WO 2011/101077 A1, filed with priority of DE 10 2010 008 448 A1, discloses a UHT plant for processing thermosensitive liquid food, in which the first transport device is connected to a vacuum chamber designed as a displacement pump. It is placed downstream of the injection vessel in the line. In its bottom region, ie at the bottom tapering towards the outlet, the injection vessel has cooling at the bottom. Thus, the displacement pump can be placed at an unquantified distance from the injection vessel to the outlet, or in the case of a rim, the outlet enters directly into the displacement pump. In the case of displacement pumps, preferably a rotary type is used, which can be designed, for example, as a geared or vane pump, a mixed flow pump, an impeller pump or a rotary piston pump, as described above. In general, an oscillating displacement pump can also be used when the volume flow fluctuations caused by the oscillating operation are compensated for by appropriate means or are irrelevant in the process.

In WO 2016/012026 A1, the plant known from EP 0 794 706 B1 was adapted for the heat treatment of thermosensitive liquid food products, together with other modified configurations of the individual aggregates of the plant. A cooling shell, which encloses the bottom of the injection vessel, serving to cool the bottom, now extends under the pump and, according to an advantageous embodiment, into the pump housing. The pump is a displacement pump, preferably a gear pump or a piston pump. However, a centrifugal pump is also claimed, without specifying exactly how the centrifugal pump is structurally designed. Accordingly, a person skilled in the art can assume that a conventional hydrodynamically optimized centrifugal pump known for its general structure is provided here.

WO 2010/086082 A1, filed with priority of DE 10 2009 006 248 A1, describes an injection system for liquid food to be heated, the injection chamber having a lower bottom with cooling. The injection chamber is connected to the outlet at the lower bottom and continues to the outlet pipe with cooling. Whether the outlet pipe flows directly or indirectly through the connecting line into the designed conveyance in any way, it remains open.

Centrifugal pumps for liquid foods, which are not a problem, such as water, are well known in their general construction. It is constructed and designed to have the highest possible hydraulic efficiency, ie to achieve the maximum possible product of volume flow and feed height with constant operating power. The impeller with blades is generally arranged on a shaft in a pump housing which consists of at least two housing parts. Within the pump housing, a distributor, for example in the form of a spiral housing or a bladeless round space, is connected to the outside of the impeller outlet cross-section which surrounds it in an annular manner. On the inlet housing part, the housing cover, the outlet is generally designed as a so-called inlet connector and is located coaxially with the impeller shaft extending tangentially on the circumferential side, and the inlet is generally designed as a so-called pressure connector. The housing part, the housing rear wall facing away from the inlet side, and the impeller pressure rear side form a so-called rear wheel side space with a generally low axial extension in view of the good hydraulic efficiency of the centrifugal pump. This axial or wide-gap extension is long enough to ensure the mechanical functioning of the centrifugal pump in the case of acceptable production tolerances. In the same way, the impeller front side, here the front side free blade rim in the case of the so-called open impeller, is adjusted with the smallest possible gap with respect to the travel of the housing cover. In order to reduce the axial force due to the pressing force acting on the impeller from both sides, several pressure compensation boreholes having a relatively small diameter are generally arranged in the hub region of the impeller, and spanning its circumference on the rear side of the impeller. are distributed

For the first named type of thermosensitive liquid food, it is of paramount importance that, while being conveyed through the centrifugal pump, there is the smallest possible tendency to deposit on the walls of the centrifugal pump. For example, when liquid food with high heat sensitivity is directly heated in the injection container, and then the heated liquid food is discharged out of the injection container by a downstream centrifugal pump having a conventional structure, that is, a hydraulically optimized structure, this Centrifugal pumps have been found to clog or shut down due to product contamination in a very short time, hence the associated seconds to minutes. In particular, the critical area is the suction area of the impeller, since undissolved gas and especially uncondensed steam can intensify the contamination of the product and narrow the wide-gap rear wheel space.

For the specific design of centrifugal pumps in plants for processing thermosensitive liquid food products that are not directly heated by cooking steam, no satisfactory solution is known to date in terms of a sufficiently long service life of the centrifugal pump.

It is an object of the present invention to devise and provide a method of a general type, equipment for carrying out said method and a centrifugal pump for said equipment, and an impeller for said centrifugal pump, which treats heat-sensitive liquid food of the type initially named while reducing the tendency of contamination during production inside the infusion vessel and into and from the centrifugal pump, in particular the centrifugal pump has a significantly increased service life in connection with the hydraulically optimized centrifugal pump according to the prior art. A further object is also to modify a centrifugal pump, which is preferably commercially available, in order to suppress the increase in product contamination in its critical region and thereby achieve the desired extension of the service life.

Said object is solved by a method having the features of claim 1 . An advantageous design of the method according to the invention is the subject of the relevant dependent claims. Equipment for carrying out the method is the subject of independent claim 10. Advantageous embodiments of the installation according to the invention are described in the relevant dependent claims. A centrifugal pump for installations according to claim 10 is the subject of independent claim 17 . Advantageous embodiments of the centrifugal pump according to the invention are described in the relevant dependent claims. An impeller for a centrifugal pump of the claimed type is the subject of claim 38 .

The present invention is procedurally devised from a method of processing a heat-sensitive liquid food such as milk protein concentrate, baby food, liquid baby food concentrate, nutritious drink or milk used to make cheese, to form a sterile state in an injection container. The liquid food is directly heated with steam, and an amount of water corresponding to the amount of steam supplied previously is removed from the liquid food by decompression to a lower pressure, and the liquid food is removed from the liquid food by a first conveying device designed as a centrifugal pump. It is transported between heating and decompression.

It is an object of the present invention that, in the case of a process of the general type, the following treatment steps (a) to (d) are provided after direct heating, namely:

For liquid food,

(a) performing a known first cooling at the bottom of the vessel of the injection vessel at least to the outlet located therein;

(b) performing a second cooling in a tubular section directly connected to an outlet formed by an outlet pipe leading out of the injection vessel or an inlet connector of a centrifugal pump;

(c) performing third cooling in the housing cover of the pump housing of the centrifugal pump directly connected to the outlet pipe or the inlet connector; and

(d) as part of the volume flow carried in the impeller of the centrifugal pump, the volume flow being configured to open towards the housing cover of the centrifugal pump;

providing at least one planned flushing action of the pump housing and the impeller through a rear impeller gap provided between the impeller and the housing rear wall of the centrifugal pump, and a front impeller gap provided between the housing cover and the impeller, The volumetric flow is up to several times greater than the unavoidable equalization flow within the pump housing, which in each case is due to the hydrodynamically optimized design of the centrifugal pump with minimum rear and front impeller gaps, which in turn affects the mechanical function of the centrifugal pump. guaranteed, solved by steps.

Step (d) relates to the inventive solution concept. Steps (a) to (c) provide a further inventive basic concept, i.e. a concrete solution to ensure gap-free cooling of the heated liquid food which accumulates in the bottom region of the dosing vessel and is conveyed to the pressure connector of the centrifugal pump guarantee to be

To enhance cooling, one design of this method provides for the liquid food to be subjected to a fourth cooling at the housing rear wall of the pump housing.

According to an advantageous design of this method, the first and second flushing actions of the pump housing and the impeller are respectively generated by recirculation through the impeller driven by the pressure difference in the pump housing, respectively. Thus, a first flushing action is made through the rear impeller gap between the impeller and the housing rear wall, and the first flushing action is involved in flow through the impeller. A second flushing action is effected through the front impeller gap between the housing cover and the impeller, the second flushing action also involved in the flow through the impeller. Further, the third flushing action is achieved by equalizing flow between each pressure side and the inlet side of the blades of the open impeller and through the front impeller gap, the means for generating the second flushing action inevitably results in the third flushing action create with

Gapless cooling of a heated liquid food product is achieved by the first relevant proposal, if the cooling is operated independently of each other. A second proposal for reducing the associated technical cooling effort provides for cooling in which at least two cooling devices are connected in series. In both cases, as provided by the third proposal, the cooling is operated in countercurrent to the heated liquid food to optimize the cold air transfer performance.

The installation according to the invention for carrying out the method according to the invention has in part known features, namely:

멸균 상태를 형성하기 위해 스팀으로 액체 식품을 직접 가열하는 주입용기;

an injection vessel for directly heating liquid food with steam to form a sterile state;

연결 라인을 통해 주입용기와 유체 접근 가능하게 연결되고, 보다 낮은 압력으로의 감압에 의해 이전에 공급된 스팀의 양에 대응하는 양의 물이 액체 식품으로부터 제거되는 진공 챔버;

a vacuum chamber fluidly accessible to the pouring vessel through a connecting line, wherein an amount of water corresponding to the amount of steam previously supplied is removed from the liquid food by depressurization to a lower pressure;

연결 라인에 배치되고, 가열된 액체 식품을 주입용기로부터 진공 챔버로 운반하기 위한 원심 펌프로서 설계된 제 1운반장치;

a first conveying device disposed on the connecting line and designed as a centrifugal pump for conveying the heated liquid food from the pouring container to the vacuum chamber;

가열된 액체 식품의 제거를 위해 주입용기의 용기 바닥에 배치되는 유출구;

an outlet disposed at the bottom of the container of the pouring container for removal of the heated liquid food;

가열된 액체 식품의 운반을 위해 유출구에 연결되고, 주입용기밖으로 이어지는 유출 파이프 또는 원심 펌프의 유입 커넥터에 의해 형성되는 관형 섹션;

a tubular section connected to the outlet for transport of the heated liquid food product and formed by an outlet pipe leading out of the dispensing vessel or an inlet connector of a centrifugal pump;

용기 바닥에 적재되는 가열된 액체 식품의 냉각을 위한 용기 바닥측 냉매 공간;

a container bottom side refrigerant space for cooling the heated liquid food loaded on the bottom of the container;

관형 섹션을 통해 유동하는 가열된 액체 식품의 냉각을 위한 유출 파이프측 냉매 공간 또는 유입 커넥터측 냉매 공간;

a refrigerant space on an outlet pipe side or a refrigerant space on an inlet connector side for cooling the heated liquid food flowing through the tubular section;

적어도 하우징 커버 및 하우징 후방벽에 의해 형성되고, 운반되는 가열된 액체 식품의 냉각을 위한 하우징 커버측 냉매 공간을 갖는 원심 펌프의 펌프 하우징; 및

a pump housing of the centrifugal pump formed by at least the housing cover and the housing rear wall and having a housing cover-side refrigerant space for cooling the conveyed heated liquid food; and

하우징 커버쪽으로 개방된 임펠러를 갖는 원심 펌프로, 임펠러에 운반되는 가열된 액체 식품의 체적 유동의 일부에 의해, 펌프 하우징 및 임펠러의 하나 이상의 계획된 플러싱 동작이 하우징 후방벽과 임펠러 사이에 제공된 후방 임펠러 갭 및 하우징 커버와 임펠러 사이에 제공되는 전방 임펠러 갭을 통해 이루어지고, 계획된 플러싱 동작의 체적 유동은 펌프 하우징 내에서 불가피한 균등화 유동보다 최대 몇 배 더 크며, 이는 각각의 경우에 최소 후방 및 전방 임펠러 갭을 갖는 원심 펌프의 수력학적으로 최적화된 설계로 인한 것이며, 원심 펌프의 기계적인 기능을 보장하도록 설계된, 원심 펌프의 조합을 갖는다

A centrifugal pump having an impeller open towards the housing cover, wherein, by part of the volume flow of heated liquid food conveyed to the impeller, one or more planned flushing actions of the pump housing and the impeller are provided with a rear impeller gap between the housing rear wall and the impeller. and through the front impeller gap provided between the housing cover and the impeller, the volume flow of the planned flushing action is at most several times greater than the unavoidable equalization flow within the pump housing, which in each case creates a minimum rear and front impeller gap. Due to the hydraulically optimized design of the centrifugal pump with

The latter property complex represents, in addition to the cooling properties, an important aspect of the installation according to the invention.

To enhance cooling, a further embodiment provides that the pump housing has a housing rear wall side refrigerant space.

In order to realize the first flushing action, it is proposed that this action takes place through the rear impeller gap between the impeller and the housing rear wall on the way through one or more flushing bore holes arranged on the rear side of the impeller. As regards the second flushing action, a further suggestion is provided that this action takes place through the front impeller gap between the housing cover and the impeller. Further, the third flushing action is achieved by equalizing flow between the pressure side and the inlet side of each blade of the open impeller and through the front impeller gap, and the means for generating the second flushing action inevitably performs the third flushing action. create as a result

Gapless cooling of heated liquid food can be achieved by supplying the refrigerant space to the container bottom side refrigerant space, the outlet pipe side or the inlet connector side refrigerant space, the housing cover side refrigerant space and the housing rear wall side refrigerant space separately from each other, when the refrigerant is supplied separately from each other. 1 is achieved as provided by the proposal. A second proposal to reduce the technical cooling effort provides for cooling in which at least two refrigerant spaces are connected in series with each other.

A centrifugal pump according to the present invention suitable for processing equipment for heat-sensitive liquid food is a pump housing formed by an inlet, an outlet, at least one housing cover and a housing rear wall, the pump housing being designed and fluidly connected to the inlet and outlet. It is devised from a known centrifugal pump having an impeller having a pump chamber, which is rotatably accommodated in the pump chamber. Blade channels open towards the housing cover and closed by the impeller rear side towards the housing rear wall are each designed between two adjacent blades. A rear impeller gap is provided between the housing rear wall and the impeller, and a front impeller gap is provided between the housing cover and the impeller.

The basic idea of the present invention is that the impeller itself and the critical area adjacent thereto, up to the perimeter of the pump housing side of the impeller front side and the impeller rear side, are flushed with liquid food to be conveyed, whereby contamination of the product there is suppressed, further the invention The basic idea is that in the flushing operation process according to the present invention, at least the boundary of the pump housing side in the area of the housing cover is cooled at the same time.

The liquid food therefore provides a planned flushing action of the pump housing and the impeller itself, as part of its volumetric flow conveyed to the impeller. The volume flow of the planned flushing operation is therefore up to several times greater than the unavoidable equalization flow of the pump housing, due to the technically esoteric hydrodynamically optimized centrifugal pump design. This design area should not be understood by the person skilled in the art as an open-top area specification, but rather is designed for a specific application so that the required service life of the centrifugal pump is achieved, while ensuring the required throughput of the installation and hence of the centrifugal pump on an economical basis. . As a result of the technically esoteric hydrodynamically optimized design, the ratio of the planned volume flow due to the solution according to the invention to the volume flow of the unavoidable equalization flow is, depending on the particular implementation case and application, from 1.5 to 10, preferably is in the range of 2 to 5. By cooling, the tendency of liquid food to burn on the walls of the centrifugal pump is reduced. This occurs under planned abandonment of optimum hydrodynamic efficiency. In the centrifugal pump according to the invention, the volume flow is conveyed to the impeller and is increased by the sum of all quasi recirculating flushing volume flows to the volume flow drawn through the inlet connector. The flushing volume flow carries the volume from the core of the blade channel to the cooled wall of the housing and from there back to the impeller, where the unsettled steam is deposited by cooling contact, thereby reducing the tendency to contaminate the product.

The correlation shown above indicates that a centrifugal pump flushing with liquid food conveyed according to the present invention has an impeller, and the hydraulic conveying capacity for the impeller must be greater than the hydrodynamic conveying capacity of the centrifugal pump actually taking place at the pressure connector as a final result. prove it In order to realize a flushing centrifugal pump of the type described above, if a hydrodynamically optimized centrifugal pump is selected, its nominal carrying capacity must therefore be chosen to be higher by the difference of the aforementioned carrying capacity. For the same nominal carrying capacity, the outer diameter of the impeller of a flushing centrifugal pump must be greater than that of a hydraulically optimized centrifugal pump.

A specific solution for diverting the basic idea of the present invention described above is that the rear and/or front impeller gap, which must necessarily exist between the impeller and the pump housing, is increased up to several times with respect to this minimum front and rear impeller gap, This consists in ensuring the mechanical functioning of the centrifugal pump by reducing the width of the impeller in the region of the front and rear impeller gaps. By widening the impeller gap, the desired generation of the necessary flushing flow is first made possible. The respective widths of the front and rear impeller gaps can be calculated according to the special properties of the liquid food.

To enhance cooling, a further embodiment provides that the housing rear wall also has a refrigerant space through which refrigerant can flow.

Gapless cooling of the pump housing, in addition to the refrigerant space on the housing cover side and the refrigerant space on the housing rear wall side, is also proposed, so that the inlet of the centrifugal pump protrudes on the housing cover with the refrigerant space on the inlet connector side. Guaranteed if designed in the form of an inlet connector. This design is not essential from the point of view of the centrifugal pump according to the invention. The centrifugal pump, like the centrifugal pump, which is destined for the formation of an inlet connector, is suitable for a direct connection between the inlet connector of the centrifugal pump and an injection vessel provided at its bottom with a refrigerant space, this refrigerant space coming out of the bottom and having an outlet It extends down to and then continues to the final end of the injection vessel. The inlet connector can then, in this arrangement, perform the function of a tubular section connected to the final outlet of the injection vessel. An arrangement with a centrifugal pump according to the invention is also possible, wherein the outlet as the final end of the injection vessel is arranged directly on the housing cover of the centrifugal pump, where the formation of an inlet connector is intended.

In all designs, i.e. for the centrifugal pump according to the invention with or without an inlet connector in combination with an inlet connector in which the outlet or the tubular section connected thereto runs to the final end, to the bottom of the infusion vessel and to the inlet into the centrifugal pump Where applicable, it is undesirable for heated liquid food to accumulate in the connection area. This is because this build-up leads to unwanted and unspecified residence times, which must be prevented. In connection with the pouring container, the centrifugal pump according to the invention has the object of immediately and completely discharging the heated liquid food accumulated in the pouring container without clogging even in the case of intermittent formation.

In order to enhance the flushing action, each blade channel between two adjacent blades of the impeller is fluid accessible in the region of its limited rear side of the impeller with the rear impeller gap through one or more flushing boreholes passing through the rear side of the impeller. It is further proposed to be in the connection section. Thereby, the radial depth involved in the relevant flushing flow can be determined. In the most general case, the flushing borehole includes any type of passage opening; That is, a prototype that is easy to produce is not essential.

A preferred design provides that a maximum expansion is exerted in the front impeller gap on the impeller outer diameter of the impeller, and this expansion is continuously reduced to a minimum front impeller gap into the inlet in the maximum blade channel. In this regard, it is proposed that the reduction of the impeller width on the impeller outer diameter is 40 to 55%, preferably 50 to 55% of the width of the hydraulically optimized impeller. In the region of the front impeller gap, a second flushing flow is formed which extends from the outlet region of the centrifugal pump into the inlet region of the impeller. Through the expansion of the front impeller gap, even in the case of a narrow impeller gap driven by the pressure difference between the pressure side and the inlet side of the blade, the circulation of the free leading edge of the blade of the open impeller therein is significantly strengthened, so that the Accordingly, a third flushing flow is generated.

As regards the dimensions of the rear impeller gap, it is helpful if the access to the radially oriented minimum rear impeller gap, starting from the impeller outer diameter of the impeller and extending to the hub of the impeller, is extended by a maximum of 5 mm by reducing the impeller outer diameter. was found to be Furthermore, an advantageous expansion of the rear impeller gap according to the invention is that an annular face-shaped cutout is applied on the rear side of the impeller in the region between the flushing borehole and the hub of the impeller, the axial depth of which is at most 2 mm, preferably 0.5 to 1 mm.

The positioning, shaping design and dimensions of a flushing borehole are properties that determine the flushing flow involved in its radial engagement depth, its shaping and quantitative strength. When arranging a single flushing borehole in each blade channel, it is advantageous from a flow and production point of view if all of these flushing boreholes are disposed on a single hole circle having a corresponding spacing.

With respect to the positioning of the flushing borehole in the blade channel, the geometrical position for each penetration point of the flushing borehole with the impeller rear side, which also determines the diameter of the hole circle, is:

관통 지점에서 블레이드의 이격 거리에 대해, 대략적으로 블레이드 채널의 중심을 통해, 그리고

for the spacing of the blade from the point of penetration, approximately through the center of the blade channel, and

대략적으로 그의 유입구와 배출구 사이의 블레이드 채널의 최대 유동 필라멘트 길이의 중심을 통해 결정되는 것이 유리한 것으로 규명되었다.

It has been found advantageous to be determined approximately through the center of the maximum flow filament length of the blade channel between its inlet and outlet.

delete

The flushing bore hole is designed to be circular with the diameter of the bore hole, or has a shape that deviates from the circular shape with a hydraulic diameter associated with this shape. The hydraulic diameter is a dimension known as the quotient of the passage cross-sectional area of the flushing borehole and the circumference of the flushing borehole 4 times. It has been found helpful if the borehole diameter or hydraulic diameter is 30-50%, preferably 40-50% of the spacing between the blades at the point of penetration.

According to a further design, the present invention also provides one or more flushing boreholes in each blade channel, each of several flushing boreholes of the blade channel being disposed on an associated hole circle, the hole circles being spaced apart from each other. Therefore, as the difference in the radial direction of the flushing bore hole spaced apart from the rotational shaft of the centrifugal pump decreases, the impact pressure difference in the flushing bore increases, and as the diameter of the hole circle decreases, the passage cross-sectional area of the flushing bore hole on different hole circles becomes small. The ground helps.

In order to ensure cooling that satisfies the special characteristics of the heated liquid food, the present invention provides a circuit of the refrigerant space as follows. According to the first proposal related thereto, the refrigerant is separately supplied to the refrigerant space at the inlet connector side, the refrigerant space at the housing cover side, and the refrigerant space at the rear wall side of the housing in cases where it is currently applicable. The second proposal provides a design variant in which at least two aforementioned refrigerant spaces are connected in series with each other. It is provided according to the third proposal that the refrigerant space on the inlet connector side is an integral section with the refrigerant space on the housing cover side.

In order to make the prerequisites for the flushing action of the rear and/or front impeller gaps, the present invention starts with a hydraulically optimized centrifugal pump, preferably a commercially available centrifugal pump, in which the rear and front impeller gaps are enlarged. provides to be this is:

임펠러의 양방향 회전, 또는

rotation of the impeller in both directions, or

하우징 커버와 하우징 후방벽 사이에 배치되는 펌프 샤프트의 방향으로 축방향으로 작용하는 스페이서 요소에 의해 확장되며, 임펠러는 하우징 후방벽에 대해 오프셋되지 않거나, 펌프 챔버 내의 펌프 샤프트와 또는 그에 대응하여 축방향으로 오프셋됨으로써 실현된다.

is extended by a spacer element acting axially in the direction of the pump shaft disposed between the housing cover and the housing rear wall, the impeller being either not offset with respect to the housing rear wall or axially with or corresponding to the pump shaft in the pump chamber It is realized by being offset by .

The selection of a hydrodynamically optimized centrifugal pump for this purpose is made in relation to the difference in the aforementioned nominal carrying capacity between a flushing type centrifugal pump and a hydrodynamically optimized centrifugal pump.

The invention also includes an impeller of a centrifugal pump, which is accommodated in a rotatable manner in the pump chamber of the centrifugal pump, the centrifugal pump being designed as described above.

BRIEF DESCRIPTION OF THE DRAWINGS A more detailed description of the invention is made with reference to the following description and accompanying drawings, including the claims. The invention is realized in various designs of a method of a general type, in various embodiments of equipment for carrying out this method and in various embodiments of a centrifugal pump for such equipment, while housing the impeller according to the invention in its pump housing and , A preferred exemplary embodiment of a centrifugal pump according to the present invention, which is fluidly connected with the outlet of the injection vessel, will be described below on the basis of the drawings.

During the processing of thermosensitive liquid food products (P), it ensures that the tendency of food contamination into the dosing vessel and therefrom into the centrifugal pump is reduced, in particular the centrifugal pump has a significantly longer service life compared to centrifugal pumps which are hydraulically optimized according to the prior art. It has a long life and guarantees the mechanical function of the centrifugal pump.

1 is a schematic diagram showing a treatment facility for a thermosensitive liquid food according to the prior art.
Figure 2 is a schematic diagram showing an injection container for direct heating of liquid food directly connected to a rotary displacement pump, known in the prior art;
Fig. 3 shows the centrifugal pump in a direction perpendicular to both the axis of rotation and the longitudinal axis of its pressure connector, the axis of rotation being oriented in the direction of gravity, the centrifugal pump being arranged directly on the outlet of the injection vessel;
FIG. 4 is a front view of the impeller of the centrifugal pump according to FIG. 3 , together with enlarged views of the first and third flushing flows S1 , S3 .
FIG. 5 is a side view showing a meridian cross-section through the impeller according to FIG. 4 along the cut-off line marked AA, with a schematic illustration of the first and second flushing flows S1 , S2 .

The installation 1000 according to FIG. 1 known in the prior art (eg WO 2011/101077 A1) is an injection vessel 50* of the first type (eg WO 2010/086082 A1) known in the art. The container 50 has in its head space a product inlet 60 , through which it supplies the liquid food P to be heat-treated to the injection container 50* of the first type centrally and in an annular manner. The first steam D1 is supplied radially outward to the liquid food P supplied for direct heating through the outer steam inlet 62 , and the second steam D2 is supplied internally through the inner steam inlet 64 . is supplied radially from Refrigerant is supplied to the first type injection vessel 50* through the injector side refrigerant inlet 66 to the vessel bottom side refrigerant space 50.4 for cooling (K) of the first type injection chamber 50* bottom. do. The refrigerant is discharged through the refrigerant outlet 68 on the injector side.

The outlet of the first type injection container 50* is connected to the first conveying device 54 through the outlet pipe 52 surrounded by the refrigerant space 52.1 on the outlet pipe side, and the first conveying device 54 is , designed as a displacement pump, preferably as a rotary pump, arranged in a connection line 70 running from the first conveying device 54 to the inlet of the vacuum chamber 56 . The first conveying device 54 conveys the heated liquid food P from the injection container 50* of the first type to the vacuum chamber 56 . The vacuum chamber 56 is designed to remove an arbitrary amount of water W as so-called vacuum steam from cooling the heated liquid food P by decompression, which is the first steam D1 and the second steam D2. In the present case consisting of ), steam (D) is supplied to the top of the injection vessel 50* of the first type in the form of steam, preferably diverted via a steam outlet 72 arranged in the upper region. The liquid food product P* treated in this way passes through a vacuum chamber ( 56) exits.

2 is a second type of known injection container 500, showing the injection container 50 directly connected to the rotary displacement pump 540 at the outlet for discharging the heated liquid food P downward (WO 2016) /012026 A1). Liquid food (P) is fed centrally to the head region of a second type injection vessel (540) through a product inlet (60), and a first steam (D1) passes through a central product stream through an outer steam inlet (62). It is introduced radially from the outside in an enclosing manner. The bottom of the second type of injection vessel 500 is provided with provisions for cooling K extending down to the rotary displacement pump 540 and into the pump housing. The refrigerant is supplied through the pump-side refrigerant inlet 67 in the rotary displacement pump 540 , and the refrigerant is discharged through the injector-side refrigerant outlet 68 .

The arrangement position of the centrifugal pump 54 according to the present invention shown in Fig. 3, in which the axis of rotation of the pump shaft 96 is oriented in the direction of gravity, allows the centrifugal pump 54 to be connected through an inlet 76 designed as an inlet connector. Suitable for direct connection to the outlet 50.3 at the vessel bottom 50.2 of the dispensing vessel 50 (which may be designed as a first or second type of dispensing vessel 50*, 500 ), then these designs are shown . The injection vessel 50 is connected to a cylindrical vessel casing 50.1 above the vessel bottom 50.2, which preferably tapers downward. The vessel bottom 50.2 and the partial cross-section of the vessel casing 50.1 connected thereto have a vessel-side refrigerant space 50.4, which is a first refrigerant inlet 78 for supplying refrigerant for cooling K1 of the vessel bottom. and a first refrigerant outlet 80 for discharging.

Centrifugal pump 54 is suitable for a special way of conveying thermosensitive liquid food P, such as milk protein concentrate, baby food, liquid baby food concentrate, nutritional drink or milk used to make cheese, and the food is ) into a connection line 70 leading to a vacuum chamber 56 and exits at an outlet 94 designed as a pressure connector. The centrifugal pump 54 also has a pump housing 12 in the known manner formed by at least one housing cover 8 and a housing rear wall 10 . A pump chamber 98 that receives the impeller 100 (see, in this case, FIGS. 4 and 5 ) in a rotating manner, and fluidly connected with an inlet 76 and an outlet 94 , comprises a pump housing 12 . ) is designed in The tubular sections 52 , 76 are connected to an outlet 50.3 , which may be formed by an outlet pipe 52 leading out of the filling vessel 50 , or by an inlet connector 76 of the centrifugal pump 54 . have. If the tubular section 52, 76 is designed as the outlet pipe 52, it can be surrounded by the refrigerant space 52.1 on the outlet pipe side; If it is designed as the inlet connector 76 , it can be surrounded by the refrigerant space 76.1 on the inlet connector side. In both cases, the refrigerant for cooling K2 of the outlet pipe or inlet connector is supplied to the refrigerant spaces 52.1 and 76.1 through the second refrigerant inlet 82 and discharged through the second refrigerant outlet 84 .

The housing cover 8 preferably has a housing cover-side refrigerant space 8.1 which either completely surrounds the housing cover 8 or partially abuts, for example in the form of a cooling pocket. The refrigerant for cooling (K3) of the housing cover is supplied to the housing cover side refrigerant space 8.1 through the third refrigerant inlet 86 and discharged through the third refrigerant outlet 88. The housing rear wall 10 can preferably have a refrigerant space 10.1 on the housing rear wall side which abuts the housing rear wall 10 fully or partially, for example in the form of cooling pockets. The refrigerant for cooling (K4) of the rear wall of the housing is supplied to the housing rear wall side refrigerant space 10.1 through the fourth refrigerant inlet 90 and discharged through the fourth refrigerant outlet 92. Finally, FIG. 3 schematically shows the first flushing flow S1 , the second flushing flow S2 and the third flushing flow S3 according to the present invention, described in more detail in FIGS. 4 and 5 , and schematically indicated.

4 and 5 show, preferably respectively, with the blade 2 positioned perpendicular to the impeller rear side 4 , bent in one plane to the rear and with respect to the direction of rotation n (see FIG. 4 ). , representing an impeller 100 which is open towards the housing cover 8 and closed towards the housing rear wall 10 by the impeller rear side 4 , between two adjacent blades 2 respectively a blade channel 2.1 is formed. do. The back bending blades are not an essential feature of the impeller 100 for the centrifugal pump 54 according to the present invention. A blade bent forward in a plane or simply oriented in a radial direction, or even a spatial bending, can be implemented without limitation in terms of realizing the flushing centrifugal pump 54 according to the invention. The rear side RS of the impeller 100 formed mainly by the impeller rear side 4 is spaced apart from the housing rear wall 10 by the rear impeller gap s1 ( FIG. 5 ). The front side VS of the impeller 100 formed mainly by the leading edge of the blade 2 is also spaced apart from the housing cover 8 by the front impeller gap s2.

The rear and/or front impeller gaps s1, s2 extend at most several times (1.5 to 10 times, preferably 2 to 5 times) over the minimum rear and front impeller gaps s1*, s2* of this type. This reduces the width of the impeller 100 in the region of the rear and front impeller gaps s1, s2, thereby ensuring the mechanical function of the centrifugal pump 54.

A preferred embodiment is that the front impeller gap s2 has a maximum extension to the impeller outer diameter DL of the impeller 100 and continues down to the smallest front impeller gap s2* into the inlet area in the largest blade channel 2.1. is reduced by This type of reduction in the width of the impeller 100 on the impeller outer diameter DL is preferably 40 to 55%, preferably 50 to 55% of the width of the hydraulically optimized impeller.

A further preferred embodiment is the impeller outer diameter, starting at the impeller outer diameter DL of the impeller 100 and approaching the radially oriented minimum impeller gap s1* extending to the hub of the maximum impeller 100 , the impeller outer diameter DL expands in a reduced way by a maximum of 5 mm, so that the impeller 100 retracts again slightly radially outward with respect to the pump housing 12 . The expansion of the rear impeller gap s1 is made according to the invention, preferably annular in the region between the flushing bore hole 6 on the impeller rear side 4 and the hub of the impeller 100 (see FIG. 5 ). A planar cutout 2.3 is applied, the axial depth of which is at most 2 mm, preferably between 0.5 and 1 mm. The dimensions of the rear and/or front impeller gaps s1, s2 in the manner described above depend on the special properties of the heated liquid food P, preferably determined in field tests.

Each blade channel (2.1) between two adjacent blades (2) of the impeller (100) passes through one or more flushing bore holes (6) through the impeller rear side (4) of its adjacent impeller rear side (4). fluidly accessible connection with the rear impeller gap s1 in the region (see FIG. 5 ).

According to a preferred embodiment, all of these flushing bore holes 6 have a diameter d of the hole circle in the case of a single flushing bore hole 6 in each blade channel 2.1 and are formed on a single hole circle 2.2. are placed Thus, the geometrical position for each penetration point of the flushing bore hole 6 together with the impeller rear side 4, which determines the diameter d of the hole circle, with respect to the spacing of the blade 2 at the penetration point , approximately through the center of the blade channel 2.1 and approximately through the center of the maximum flow filament length of the blade channel 2.1 between its inlet and outlet.

The flushing borehole 6 is preferably designed to be circular with the diameter Db of the borehole, or has a shape deviating from the circle to have a hydraulic diameter Dh associated with this shape ( FIG. 4 ). Accordingly, the diameter Db or hydraulic diameter Dh of the bore hole is 30 to 50% of the distance from the blade 2 at the point of penetration, preferably 40 to 50%.

The invention further provides that one or more flushing bore holes 6 are provided in each blade channel 2.1, several flushing bore holes 6 of the blade channel 2.1 are respectively arranged on the associated hole circle 2.2, , providing that the hole circles 2.2 are radially spaced apart from each other. The flushing bore holes 6 on different hole circles 2.2 have the same diameter Db or hydraulic diameter Dh, or different diameters Db or hydraulic diameter Dh from the hole circle to the hole circle. Each can be designed. Due to the radially inward to outwardly decreasing pressure differential between the rear wheel space and the blade channel 2.1, the preferred embodiment is a flushing bore hole 6 on the hole circle 2.2 which differs according to the diameter d of the decreasing hole circle. to make the passage cross-section of the Thus, when flushing volume flow is to be achieved, the bore diameter Db or hydraulic diameter Dh of the flushing bore hole 6 tends to be smaller the closer to the hub region of the impeller 100 .

At least a housing cover (8) having a refrigerant space (8.1) on the housing cover side through which the refrigerant can flow is provided. If necessary, the housing rear wall 10 may be cooled through the housing rear wall side refrigerant space 10.1. According to an advantageous embodiment, in addition to the housing cover side refrigerant space 8.1 and the housing rear wall side refrigerant space 10.1, when designed as an inlet connector, the inlet 76 has an inlet connector side refrigerant space 76.1 . It is proposed that the refrigerant space 76.1 on the inlet connector side, the refrigerant space 8.1 on the housing cover side and the refrigerant space 10.1 on the housing rear wall side are separately supplied with each other. Another embodiment provides that at least two of the refrigerant spaces 76.1, 8.1, 10.1 are connected in series with each other. According to a further proposal, the refrigerant space 76.1 on the inlet connector side is an integral section with the refrigerant space 8.1 on the housing cover side.

The following method in which the centrifugal pump according to the prior art will be modified according to the present invention is used in the same sense as the flushing operation of the impeller 100 according to the present invention (hereinafter, 'plus operation' is used in the same sense as 'flushing flow') either alone or with each other to ensure a combination with:

● The expansion of the rear impeller gap (s1) and/or the front impeller gap (s2) is (see Fig. 5)

○ Bi-directional rotation of the impeller 100, or

o is extended by a spacer element acting axially in the direction of the pump shaft 96 disposed between the housing cover 8 and the housing rear wall 10 , the impeller 100 relative to the housing rear wall 10 . Either not offset or axially offset relative to the pump shaft 96 in the pump chamber 98 .

• Arrangement of the aforementioned flushing bore holes 6 in the manner described above.

4 and 5 show the effect of the above-described method according to the present invention. By widening the rear impeller gap s1, or by approaching it, respectively, an enlarged approach thereto, the associated rear wheel-side space is supplied with a dominant static pressure on the outlet side of the impeller 2 in a somewhat unrestricted manner over its entire radial extension area. over the impeller outer diameter (DL). A lower static pressure than the rear wheel side space exists in each flushing bore hole 6 in the blade channel 2.1. As shown in FIGS. 5 and 4 , the first flushing flow S1 directed radially from the inside to the outside exists only in the latter case, for example, on the blade channel 2.1, so that the blade channel from the rear wheel side space. (2.1) The causal flow through of the flushing bore hole (6) into (2.1) creates a blade channel (2.1). The heated liquid food P located in the rear wheel side space can be cooled in the housing rear wall 10, so that cooling of the housing rear wall K4 is provided, if applicable, by the first flushing flow S1. The permanently cooled liquid food P now preferably enters the core region of the flow in the blade channel 2.1.

With the aforementioned expansion of the front impeller gap s2 , as shown in the upper left quadrant of the impeller 100 in FIG. 4 , as viewed through the free front rim of the blade 2 , which is the respective front side, its radius A third flushing flow S3 may be formed over the directional expansion region. The driving force for this third flushing flow S3 results from the pressure difference in each blade 2 given by the static pressure on the blade upper side and the static pressure on the blade bottom side, the suction side SS. The third flushing flow S3 ensures a further movement in and generally circumferentially relative to the housing cover 8 and thus a forced cooling of the liquid food P, which in turn ensures cooling of the housing cover K3 ) is installed on the housing cover 8 (see FIG. 5). Furthermore, the third flushing flow S3 here also causes an exchange of liquid food in and out of the flow core region in the associated blade channel 2.1 . Through the expanded front impeller gap s2, a radially oriented second flushing flow S2 is formed due to the difference between the static pressure at the outlet of the impeller 100 and the static pressure at the inlet inlet of the impeller 100 (see FIG. 5), which overlaps with the third flushing flow S3. In addition, this second flushing flow S2 also ensures the exchange of liquid food P into and out of the flow core region in the associated blade channel 2.1.

An exemplary embodiment of a centrifugal pump 54 according to the invention:

The centrifugal pump 54 is driven by a drive motor with a nominal capacity of 15 kW at a nominal speed n = 2900/1 min. The impeller outer diameter (DL) is reduced from the original 205 mm to 195 mm. The impeller width of the impeller outer diameter DL is reduced from the original 19 mm to 9 mm, with this reduction continuing the inlet area into the blade channel 2.1 down to the minimum front impeller gap s2*. The rear impeller gap s1 extends by 0.7 mm in the area of the annular-shaped cutout 2.3 relative to the minimum rear impeller gap s1*. Each flushing bore hole 6 in the associated blade channel 2.1 of a total of six blade channels 2.1 is circular in design and has a bore hole diameter Db of 10 mm.

The method described above according to the present invention can be applied similarly to a closed impeller, and in the following manner, the third flushing flow S3 through the front edge of each blade 2 is not possible as expected. do. As an alternative to this flushing path, the cover plate of the impeller 100 would then be provided with additional flushing bore holes formed between the cover plate and the housing cover 8, each connecting the associated blade channel with the front wheel side space. be able to Next, a flushing flow suitable for the first flushing flow S1 described above takes place.

1 and 2 (prior art)
1000 facilities
50 full infusion container
50* Type 1 injection container
500 Type 2 injection vessel
50.4 Refrigerant space at the bottom of the vessel
52 Outflow pipe
52.1 Refrigerant space on the outlet pipe side
54 First transport device
540 Rotary Displacement Pump
56 vacuum chamber
58 Second transport device
60 product entrance
62 Outer steam inlet
64 inner steam inlet
66 Refrigerant inlet on injector side
67 Refrigerant inlet on the pump side
68 Refrigerant outlet on the injector side
70 connection line
72 steam outlet
74 (for processed food) discharge line
D Steam
D1 1st Steam
D2 2nd Steam
K cooling
P liquid food
P* processed food
W water
Fig. 3
50 infusion container
50* Type 1 injection container
500 Type 2 injection vessel
50.1 Vessel Casing
50.2 Vessel bottom
50.3 Outlet
50.4 Refrigerant space at the bottom of the vessel
8 housing cover
8.1 Refrigerant space on housing cover side
10 Housing rear wall
10.1 Refrigerant space on the rear wall of the housing
12 Pump housing
54 centrifugal pump
76 inlet (inlet connector)
76.1 Refrigerant space on the inlet connector side
78 First refrigerant inlet
80 1st refrigerant outlet
82 Second refrigerant inlet
84 Second refrigerant outlet
86 Third refrigerant inlet
88 Third refrigerant outlet
90 4th refrigerant inlet
92 4th refrigerant outlet
94 Outlet (Pressure Connector)
96 pump shaft
98 pump chamber
100 impeller
Cooling of the bottom of the K1 vessel
Cooling of the K2 outlet pipe or inlet connector
Cooling of the K3 housing cover
Cooling of the rear wall of the K4 housing
S1 first flushing operation (first flushing flow)
S2 second flushing operation (second flushing flow)
S3 third flushing operation (third flushing flow)
4 and 5
2 blades
2.1 Blade Channel
2.2 Hall One
2.3 Toroidal shape cutout
4 Impeller rear side
6 flushing bore hole
DL impeller outer diameter
Db bore hole diameter
Dh hydraulic diameter
DS pressure side (blade)
RS rear side (impeller)
SS inlet (blade)
VS front side (impeller)
d diameter of hole circle
s1 rear impeller gap
s1* minimum rear impeller gap
s2 front impeller gap
s2* minimum front impeller gap
n direction of rotation

Claims (38)

The amount of steam (D) previously supplied by directly heating the liquid food (P) with steam (D) to form a sterile state in the injection vessel (50; 50*, 500) and decompression to a lower pressure An amount of water W corresponding to In the treatment method of P), after direct heating, the following treatment steps (a) to (e), i.e.:
About liquid food (P)
(a) performing a first cooling (K1) at least at the bottom of the vessel (50.2) of the injection vessel (50; 50*, 500) up to the outlet (50.3) located at the bottom of the vessel;
(b) tubular sections 52 , 76 which are connected directly to the outlet 50.3 formed by the outlet pipe 52 leading out of the injection vessel 50 ; 50*; 500 or the inlet connector 76 of the centrifugal pump 54 . ) performing a second cooling (K2) in;
(c) performing a third cooling (K3) in the housing cover (8) of the pump housing (12) of the centrifugal pump (54) directly connected to the outlet pipe (52) or the inlet connector (76); and
(d) as part of a volume flow carried in the impeller 100 of the centrifugal pump 54 and configured to open toward the housing cover 8 of the centrifugal pump 54, with the housing rear wall 10 of the centrifugal pump 54 and One of the pump housing 12 and the impeller 100 through the rear impeller gap s1 provided between the impellers 100 and the front impeller gap s2 provided between the housing cover 8 and the impeller 100 providing the above planned flushing action, wherein the volume flow of the planned flushing action is up to several times greater than the unavoidable equalization flow within the pump housing 12 , which in each case is the minimum rear and front impeller gap s1*, s2 *) due to the hydrodynamically optimized design of the centrifugal pump 54 having the The method of claim 1,
A method for processing a heat-sensitive liquid food (P), characterized in that the liquid food (P) is subjected to a fourth cooling (K4) in the housing rear wall (10) of the pump housing (12). 3. The method of claim 1 or 2,
The flushing operation includes a first flushing operation S1 in which the fluid flow occurs through the rear impeller gap s1 and a second flushing operation S2 in which the fluid flow occurs through the front impeller gap s2, wherein the first and the second flushing operations S1 and S2 are respectively generated by recirculation through the impeller 100 driven by the pressure difference within the pump housing 12, respectively. . 4. The method of claim 3,
The first flushing operation S1 is made through the rear impeller gap s1 between the impeller 100 and the housing rear wall 10, and the first flushing operation S1 is involved in the flow through the impeller 100 A method for treating a heat-sensitive liquid food (P), characterized in that. 5. The method of claim 4,
The second flushing operation (S2) is made through the front impeller gap (s2) between the housing cover (8) and the impeller (100), the second flushing operation (S2) is involved in the flow through the impeller (100) A method of treating a thermosensitive liquid food (P) characterized in that it is 6. The method of claim 5,
The third flushing operation (S3) is effected by equalizing flow between the pressure side and the inlet side of each blade (2) of the open impeller (100) and through the front impeller gap (s2). A method of processing food (P). 4. The method of claim 3,
The first cooling (K1), the second cooling (K2), the third cooling (K3), and the fourth cooling (K4) are each operated separately from each other. 7. The method of claim 6,
The first cooling (K1), the second cooling (K2), the third cooling (K3), and the cooling of at least two of the fourth cooling (K4) of the thermosensitive liquid food (P), characterized in that connected in series processing method. 9. The method of claim 8,
The first cooling (K1), the second cooling (K2), the third cooling (K3), and the fourth cooling (K4) are heat-sensitive liquid food, characterized in that it is operated in countercurrent to the heated liquid food (P) (P) treatment method. In the processing facility 1000 of the heat-sensitive liquid food (P),

Injection container (50; 50*, 500) for directly heating liquid food (P) with steam (D) to form a sterile state;

A water ( a vacuum chamber 56 in which W) is removed from the liquid food P;

a first conveying device 54 disposed on the connection line 70 and designed as a centrifugal pump for conveying the heated liquid food P from the injection container 50; 50*, 500 to the vacuum chamber 56;

an outlet 50.3 disposed in the container bottom 50.2 of the injection container 50; 50*, 500 for removal of the heated liquid food P;

Connected to the outlet 50.3 for transport of the heated liquid food P, by the outlet pipe 52 or the inlet connector 76 of the centrifugal pump 54 leading out of the pouring vessel 50; 50*, 500 tubular sections (52, 76) formed;

a container bottom side refrigerant space (50.4) for cooling the heated liquid food (P) loaded on the container bottom (50.2);

an outlet pipe side refrigerant space 52.1 or an inlet connector side refrigerant space 76.1 for cooling of the heated liquid food P flowing through the tubular sections 52 and 76;

A pump housing ( 12); and

With a centrifugal pump 54 having an impeller 100 open towards the housing cover 8 , by part of the volume flow of heated liquid food P conveyed on the impeller 100 , the pump housing 12 and the impeller A rear impeller gap s1 provided between the housing rear wall 10 and the impeller 100 and a front impeller gap s2 provided between the housing cover 8 and the impeller 100 in which one or more planned flushing operations of 100 are provided ), the volume flow of the planned flushing action is at most several times greater than the unavoidable equalization flow within the pump housing 12, which in each case has a minimum rear and front impeller gap s1*, s2* Due to the hydrodynamically optimized design of the centrifugal pump (54), a treatment facility for thermosensitive liquid food (P) comprising a centrifugal pump (54), designed to ensure the mechanical function of the centrifugal pump (54). 11. The method of claim 10,
A heat-sensitive liquid food (P) processing facility, characterized in that the pump housing (12) has a refrigerant space (10.1) on the rear wall side of the housing. 12. The method of claim 10 or 11,
A first flushing operation S1 is carried out through the rear impeller gap s1 between the impeller 100 and the housing rear wall 10 on the way through one or more flushing bore holes 6 disposed on the impeller rear side 4 A processing facility for heat-sensitive liquid food (P), characterized in that it is made. 13. The method of claim 12,
A treatment facility for heat-sensitive liquid food (P), characterized in that the second flushing operation (S2) is performed through the front impeller gap (s2) between the housing cover (8) and the impeller (100). 14. The method of claim 13,
Thermosensitive liquid food, characterized in that the third flushing operation (S3) is made by equalizing flow between each pressure side and the inlet side of the blade (2) of the open impeller (100) and through the front impeller gap (s2) (P) processing equipment. 15. The method of claim 14,
Refrigerant is individually supplied to the container bottom side refrigerant space (50.4), the outlet pipe side or inlet connector side refrigerant space (52.1, 76.1), the housing cover side refrigerant space (8.1), and the housing rear wall side refrigerant space (10.1). A processing facility for heat-sensitive liquid food (P), characterized in that. 15. The method of claim 14,
At least two refrigerant spaces among the refrigerant spaces (50.4, 52.1, 76.1, 8.1, and 10.1) are connected in series with each other. A pump housing 12 formed by an inlet 76, an outlet 94, one or more housing covers 8 and a housing rear wall 10, which is designed in the pump housing 12 and has an inlet 76 and an outlet ( A pump chamber 98 fluidly accessible with 94, an impeller 100 having blades 2 rotatably received in the pump chamber 98, open towards a housing cover 8 and a rear wall of the housing ( A blade channel 2.1, each designed between two adjacent blades 2 closed by the impeller rear side 4 towards 10), a rear impeller gap s1 provided between the housing rear wall 10 and the impeller 100 ), and a front impeller gap (s2) provided between the housing cover (8) and the impeller (100), comprising:

The rear and front impeller gaps s1, s2 extend at most several times for the minimum rear and front impeller gaps s1*, s2* of this type, so that in the region of the rear and front impeller gaps s1, s2 the impeller ( By reducing the width of 100), the mechanical function of the centrifugal pump 54 is ensured,

Centrifugal pump for conveying heat-sensitive liquid food (P), characterized in that at least the housing cover (8) has a refrigerant space (8.1) through which the refrigerant can flow. 18. The method of claim 17,
A centrifugal pump for transporting thermosensitive liquid food (P), characterized in that the housing rear wall (10) has a refrigerant space (10.1) through which the refrigerant can flow. 19. The method according to claim 17 or 18,
In addition to the housing cover side refrigerant space 8.1 and the housing rear wall side refrigerant space 10.1, the inlet 76 is designed in the form of an inlet connector protruding on the housing cover 8, and the inlet connector side refrigerant space 76.1 ) A centrifugal pump for transporting the thermosensitive liquid food (P), characterized in that it comprises a. 18. The method of claim 17,
Each blade channel (2.1) is fluidly connected with the rear impeller gap (s1) in the region of the adjacent impeller rear side (4) via one or more flushing bore holes (6) passing through the impeller rear side (4) A centrifugal pump for transporting thermosensitive liquid food (P) characterized in that it is 18. The method of claim 17,
The maximum expansion is applied to the front impeller gap s2 on the impeller outer diameter DL of the impeller 100, characterized in that it is continuously reduced to the minimum front impeller gap s2* into the region of the inlet in the blade channel 2.1. Centrifugal pump for transporting thermosensitive liquid food (P). delete delete delete delete 21. The method of claim 20,
In the case of a single flushing bore hole (6) in each blade channel (2.1), thermosensitive liquid food (P), characterized in that these flushing bore holes (6) are all arranged on a single hole circle (2.2) ) centrifugal pumps. 27. The method of claim 26,
The geometrical position for each penetration point of the flushing bore hole 6 together with the impeller rear side 4, which also determines the diameter d of the hole circle, is:

for the spacing of the blade 2 at the point of penetration, approximately through the center of the blade channel 2.1, and

Centrifugal pump for conveying thermosensitive liquid food (P), characterized in that it is determined approximately through the center of the maximum flow filament length of the blade channel (2.1) between its inlet and outlet. 28. The method of claim 27,
The flushing bore hole (6) is a centrifugal pump for conveying the thermosensitive liquid food (P), characterized in that it is designed in a circular shape with the diameter (Db) of the bore hole. 28. The method of claim 27,
A centrifugal pump for conveying thermosensitive liquid food (P), characterized in that the flushing bore hole (6) has an out-of-circle shape with a hydraulic diameter (Dh) associated with this shape. 30. The method of claim 28 or 29,
A centrifugal pump for conveying thermosensitive liquid food (P), characterized in that the diameter (Db) or hydraulic diameter (Dh) of the bore hole is 30% to 50% of the separation distance between the blades (2) at the point of penetration. 31. The method of claim 30,
A centrifugal pump for conveying heat-sensitive liquid food (P), characterized in that the bore hole diameter (Db) or hydraulic diameter (Dh) is 40 to 50% of the separation distance between the blades (2) at the point of penetration. 21. The method of claim 20,

Each blade channel (2.1) is provided with one or more flushing bore holes (6),

Several flushing bore holes 6 of the blade channel 2.1 are respectively arranged on the associated hole circle 2.2,

A centrifugal pump for conveying thermosensitive liquid food (P), characterized in that the hole circles (2.2) are radially spaced apart from each other. 33. The method of claim 32,
A centrifugal pump for conveying heat-sensitive liquid food (P), characterized in that the passage cross-sectional area of the flushing bore hole (6) on the different hole circle (2.2) becomes smaller as the diameter (d) of the hole circle decreases. 20. The method of claim 19,
Centrifugal for conveying heat-sensitive liquid food (P), characterized in that the refrigerant space (76.1) on the inlet connector side, the refrigerant space (8.1) on the housing cover side, and the refrigerant space (10.1) on the rear wall side of the housing are respectively supplied with refrigerant. Pump. 20. The method of claim 19,
A centrifugal pump for transporting heat-sensitive liquid food (P), characterized in that at least two of the refrigerant spaces (76.1, 8.1, 10.1) are connected in series with each other. 20. The method of claim 19,
A centrifugal pump for conveying heat-sensitive liquid food (P), characterized in that the refrigerant space (76.1) on the inlet connector side is an integral section with the refrigerant space (8.1) on the housing cover side. 18. The method of claim 17,
Starting with a hydraulically optimized centrifugal pump, the rear and front impeller gaps (s1, s2) are:

Bi-directional rotation of the impeller 100, or

is extended by a spacer element acting axially in the direction of the pump shaft 96 disposed between the housing cover 8 and the housing rear wall 10 , the impeller 100 offset with respect to the housing rear wall 10 . Centrifugal pump for conveying thermosensitive liquid food (P) characterized in that it is not or is axially offset with or correspondingly from the pump shaft (96) in the pump chamber (98). delete

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