KR20190029667A - Process and equipment for treating thermosensitive liquid food and centrifugal pumps of this type - Google Patents

Abstract

The present invention relates to a method of treating a thermosensitive liquid food (P) according to the preamble of claim 1, to an apparatus for carrying out the method, and to a centrifugal pump of the above type, And the tendency of food contamination to be reduced therefrom into the centrifugal pump, and in particular the centrifugal pump has a considerably longer service life compared to a hydrodynamically optimized centrifugal pump according to the prior art. In this way, this is achieved in particular by the following process steps (c) and (d), namely: for the 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, the housing cover immediately adjacent to the outlet pipe (52) or the inlet connector (76); And (d) a volumetric flow carried by the impeller 100 of the centrifugal pump 54 (this volume flow being configured to open towards the housing cover 8 of the centrifugal pump 54) A rear impeller gap s1 provided between the rear wall 10 and the impeller 100 and a front impeller gap s2 provided between the housing cover 8 and the impeller 100, Providing more than one planned flushing operation of the impeller 100, the volumetric flow of the planned flushing operation is at most several times greater than the unavoidable equalization flow in the pump housing 12, which in each case is the minimum rear and front impeller Due to the hydrodynamically optimized design of the centrifugal pump 54 having the gaps s1 *, s2 * and ensures the mechanical function of the centrifugal pump 54. [

Description

Process and equipment for treating thermosensitive liquid food and centrifugal pumps of this type

The present invention relates to a method and apparatus for treating milk used to make a thermosensitive liquid baby food concentrate, a nutritional drink or cheese, in which the liquid food is directly heated with steam to form a sterilized condition in the injection container, The amount of water corresponding to the amount of steam previously supplied is removed from the liquid food, and the liquid food is conveyed between the heating and the reduced pressure by the first conveying device designed as a centrifugal pump. The present invention also relates to such a centrifugal pump for equipment and an impeller for such a centrifugal pump.

The thermosensitive liquid food of the type described above contains a relatively large amount of protein, a lot of dry matter and little water; These foods may have low, medium or high viscosity. The term " heat sensitivity "refers to the tendency of these foods to burn, i. E. At temperatures above 100 DEG C, to form deposits in the injection vessel and in the walls of centrifugal pumps carrying them under these conditions It is understood that there is. The formation of these sediments is also called contamination of the product. Contamination of the product reduces the service life of the centrifugal pump or the duration of each operation, especially between the injection vessel and the two wash cycles in particular.

A particularly important area of the facility for carrying out the method is the bottom area of the infusion container tapered downwardly into the outlet and the conveying device and the conveying device is between the outlet of the infusion container and the vacuum chamber serving to depressurize the heated liquid food As shown in FIG. The conveying device may be a displacement pump, for example a gear pump or a centrifugal pump. The delivery device is placed at a distance from the injection vessel, or directly at its outlet. Accumulation of heated liquid food in the connection area to the bottom area of the injection vessel and the conveying device is undesirable and results in an undefined residence time. Especially in syringes, sumps of heated liquid food should be avoided. Therefore, there were enough suggestions to solve these drawbacks.

In the case of a heating installation with an injection container, it is known to directly discharge heated liquid food outside the injection container by means of a rotary displacement pump, for example a gear pump, the housing of the pump being provided with a cooling device, And is directly connected to the outlet of the injection vessel (EP 0 784 706 B1). The gear pump has its own self-cleaning function, because the gearwheel closely engages together and sweeps along the walls of the associated housing, preventing the formation of ever-increasing deposits (contamination of the product).

WO 2011/101077 A1, which claims priority to DE 10 2010 008 448 A1, discloses a UHT facility for treating a thermally sensitive liquid food product. More particularly, the first delivery device comprises a connection to a vacuum chamber designed as a displacement pump Lt; RTI ID = 0.0 > line. ≪ / RTI > In its bottom region, i.e. the tapered bottom towards the outlet, the injection vessel has cooling in its bottom. Thus, the displacement pump can be placed at an un-quantified distance from the injection vessel to the outlet, or, in the case of the rim, the outlet directly enters the displacement pump. In the case of a displacement pump, a rotary method is preferably used, which can be designed, for example, as a gear pump or vane pump, a mixed pump, an impeller pump or a rotary piston pump, as described above. In general, the oscillating displacement pump can also be used when the volumetric flow fluctuations caused by the oscillating operation are compensated by appropriate means or are irrelevant in the process.

In WO 2016/012026 Al, the facility known through EP 0 794 706 B1 has been modified for heat treatment of thermosensitive liquid food, along with other altered configurations of individual aggregates of equipment. The cooling shell surrounding the bottom of the injection vessel serving to cool the bottom now extends below the pump, 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 an exact indication of how the centrifugal pump is structurally designed. Thus, one skilled in the art can assume that a conventional hydrodynamically optimized centrifugal pump known to its general construction is provided herein.

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

Centrifugal pumps for liquid foodstuffs, such as water, are well known for their general structure. This is constructed and designed to have the highest possible hydrodynamic efficiency, that is, to achieve the maximum possible product of volumetric flow and supply height with constant operating power. The impeller with blades is generally disposed on a shaft in a pump housing consisting of at least two housing parts. In the pump housing, for example, a spiral housing or a bladeless round space type distributor is connected to the outside of the impeller outlet section surrounding it in an annular manner. On the inlet side housing part, the housing cover, the outlet, is designed as a so-called inlet connector and is coaxially positioned with the impeller shaft extending in the tangential direction on the circumferential side, and the inlet is generally designed as a so-called pressure connector. The housing portion, the housing rear wall facing away from the inlet side, and the impeller pressure back side form a so-called rear wheel side space with generally low axial extension in terms of good hydrodynamic efficiency of the centrifugal pump. This axial or wide gap extension is sufficiently close to ensure the mechanical function of the centrifugal pump in the case of acceptable production tolerances. In the same way, the front side of the impeller, here the front free blade rim in the case of a so-called open impeller, is adjusted to the smallest possible gap for the advancement of the housing cover. In order to reduce the axial forces due to the pressing forces acting on the impellers on both sides, several pressure compensating boreholes with a relatively small diameter are generally arranged in the hub region of the impeller, .

For the first type of thermally sensitive liquid food, it is most important that the tendency to settle on the wall of the centrifugal pump during transport through a centrifugal pump is as small as possible. For example, when a liquid food having a high heat resistance is directly heated in an injection container and then the heated liquid food is discharged out of the injection container by a conventional structure, that is, a downstream centrifugal pump of a hydraulically optimized structure, Centrifugal pumps have been found to block or stop due to contamination of the product within a very short time, thus within a few seconds to a maximum of a few seconds. Particularly, the critical region is the suction region of the impeller because unmelted gas and particularly non-condensed steam enhance the contamination of the product and narrow the gap of the rear wheel side space.

In the case of a specific design of a centrifugal pump in a facility for treating thermosensitive liquid food which is not directly heated by cooking steam, satisfactory solutions for the centrifugal pump have not been known up to now in view of a sufficiently long service life of the centrifugal pump.

The object of the present invention is to provide a general type of method, an apparatus for carrying out the method and a centrifugal pump for the plant, and an impeller for the centrifugal pump, which processes the first type of thermally sensitive liquid food , Reduces the tendency of contamination in and out of the injection vessel and into and out of the centrifugal pump, and in particular, the centrifugal pump has a significantly increased service life with respect to the hydrodynamically optimized centrifugal pump according to the prior art. It is also an additional object to modify a commercially available centrifugal pump, preferably to suppress an increase in product contamination in its critical area, thereby achieving an extension of the desired service life.

This object is solved by a method having the features of claim 1. The advantageous design of the method according to the invention is the subject of a related subclause. The facility for carrying out the method is the subject of independent claim 10. Advantageous embodiments of the plant according to the invention are described in the relevant subclaims. The centrifugal pump for equipment according to claim 10 is the subject of independent clause 17. Advantageous embodiments of centrifugal pumps according to the invention are described in the relevant subclaims. The impeller for the centrifugal pump of the claimed type is the subject of claim 38.

The present invention contemplates procedures for treating thermally sensitive liquid foods such as milk protein concentrates, baby food, liquid baby food concentrates, nutritional beverages or milk used to make cheese, to form a sterile condition in the injection container The liquid food is heated directly with steam and the amount of water corresponding to the amount of steam previously supplied by the decompression to a lower pressure is removed from the liquid food and the liquid food is removed by the first conveying device designed as a centrifugal pump It is carried between heating and decompression.

It is an object of the present invention to provide the following process steps (a) to (d), which are provided after direct heating,

For liquid foods,

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

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

(c) performing a 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) a portion of a volumetric flow carried in the impeller of the centrifugal pump (which volume flow is configured to open towards the housing cover of the centrifugal pump)

Providing a rearward impeller gap provided between the housing rear wall of the centrifugal pump and the impeller and a forward impeller gap provided between the housing cover and the impeller to provide one or more planned flushing operations of the pump housing and the impeller, The volumetric flow is at most several times larger than the unavoidable equalization flow in the pump housing due to the hydrodynamically optimized design of the centrifugal pump with the minimum rear and front impeller gaps in each case and the mechanical function of the centrifugal pump , And so on.

Step (d) relates to a solution concept of the present invention. The steps (a) to (c) provide a further inventive basic concept, namely a specific solution to ensure gap free cooling of the heated liquid food that is accumulated in the bottom region of the injection vessel and carried to the pressure connector of the centrifugal pump .

To enhance cooling, one design of this method provides for performing a fourth cooling in the housing rear wall of the pump housing for the liquid food.

According to an advantageous design of the method, the first and second flushing operations 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, the first flushing operation is performed through the rear impeller gap between the impeller and the housing back wall, and the first flushing operation is involved in the flow through the impeller. The second flushing operation is accomplished through a forward impeller gap between the housing cover and the impeller, and the second flushing operation is also involved in the flow through the impeller. In addition, the third flushing operation is effected by equalization flow between each pressure side and the inlet side of the blades of the opened impeller and through the forward impeller gap, and the means for generating the second flushing operation necessarily results in a third flushing operation .

The gapless cooling of the heated liquid food is achieved by the first related proposal when the cooling is operated separately from each other. A second proposal to reduce the associated technology cooling effort provides for cooling in which at least two cooling units are connected in series. In both cases, as provided by the third proposal, the cooling is operated in countercurrent to the heated liquid food for optimization of the cold transfer performance.

The arrangement according to the invention for carrying out the method according to the invention comprises partly known features, namely:

멸균 상태를 형성하기 위해 스팀으로 액체 식품을 직접 가열하는 주입용기;

An injection vessel for directly heating the liquid food with steam to form a sterilized 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 connected to the injection vessel via a connection line and in which a quantity of water corresponding to the amount of steam previously supplied by the reduced pressure to a lower pressure is removed from the liquid food;

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

A first delivery device disposed in the connection line and designed as a centrifugal pump for delivering the heated liquid food from the injection container to the vacuum chamber;

가열된 액체 식품의 제거를 위해 주입용기의 용기 바닥에 배치되는 유출구;

An outlet disposed in the bottom of the vessel of the injection vessel 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 delivery of the heated liquid food and formed by an inlet connector of the outlet pipe or centrifugal pump leading to the outlet vessel;

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;

An outlet pipe side refrigerant space or an inlet connector side refrigerant space 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, the centrifugal pump having a housing cover side refrigerant space for cooling the heated liquid food to be conveyed; 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 that is open toward the housing cover, wherein by a portion of the volumetric flow of the heated liquid food carried by the impeller, one or more planned flushing operations of the pump housing and the impeller are effected by a rear impeller gap provided between the housing rear wall and the impeller And a front impeller gap provided between the housing cover and the impeller, the volumetric flow of the planned flushing operation being at most several times larger than the unavoidable equalization flow in the pump housing, which in each case has a minimum rear and front impeller gap Having a combination of centrifugal pumps, which is due to the hydrodynamically optimized design of the centrifugal pump and which is designed to ensure the mechanical function of the centrifugal pump

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

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

In order to realize the first flushing operation, it is proposed that this operation is carried out through the rear impeller gap between the impeller and the housing back wall in the middle through one or more flushing bore holes arranged on the rear side of the impeller. With respect to the second flushing operation, this operation is provided through a further impeller gap between the housing cover and the impeller. The third flushing operation is also effected by the equalizing flow between each pressure side and the inlet side of the blades of the opened impeller and through the forward impeller gap and the means for generating the second flushing action necessarily results in a third flushing operation .

The gapless cooling of the heated liquid food can be achieved by cooling the refrigerant space in 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, 1 < / RTI > proposal. A second proposal to reduce the technical cooling effort provides for cooling wherein at least two refrigerant spaces are connected in series with one another.

A centrifugal pump according to the present invention suitable for a treatment plant of thermosensitive liquid food comprises a pump housing formed by an inlet, an outlet, at least one housing cover and a housing rear wall, a pump housing designed for this, and fluidly connected to the inlet and outlet And a known centrifugal pump having an impeller with a pump chamber, a blade rotatably received in the pump chamber. The blade channel, which is open towards the housing cover and closed by the impeller rear side towards the rear wall of the housing, is 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 region adjacent to the impeller front side and the impeller rear side boundary to the pump housing side boundary are flushed with the liquid food to be conveyed thereby to suppress the contamination of the product therein, Is that the boundary of the pump housing side is cooled at the same time in the region of the housing cover during the flushing operation according to the present invention.

Thus, the liquid food, as part of its volumetric flow conveyed to the impeller, provides a planned flushing operation of the pump housing and the impeller itself. The volumetric flow of the planned flushing operation is therefore up to several times larger than the unavoidable equalization flow of the pump housing, due to the technically difficult hydrodynamically optimized centrifugal pump design. This design area is not intended to be understood by those skilled in the art as a top open area specification and is designed for a specific application so as to achieve the required service life of the centrifugal pump while ensuring the required throughput on the equipment and therefore the centrifugal pump on an economical basis . As a result of the technically difficult hydrodynamically optimized design, the proportion of the planned volume flow due to the measures according to the invention for the volumetric flow of unavoidable equalization flows is in the range of 1.5 to 10, preferably Is in the range of 2 to 5. By cooling, the tendency of the liquid food to burn in the wall of the centrifugal pump is reduced. This occurs under planned abandonment of optimal hydraulic efficiency. In the centrifugal pump according to the invention, the volume flow is carried by the impeller and is increased by the sum of all the quasi recirculating flushing volumetric flows for the volume flow sucked through the inlet connector. The flushing volumetric flow transports the volume back to the impeller from the core of the blade channel to the cooled wall of the housing and from there, and the precipitated precipitate is precipitated by the cooling contact, thereby reducing the tendency of the product to become contaminated.

The correlation shown above is that the liquid food conveyed according to the invention has a flushing centrifugal pump with an impeller and the hydraulic carrying capacity for the impeller is greater than the hydrodynamic carrying capacity of the centrifugal pump actually occurring in the pressure connector Prove that. In order to realize a flushing type centrifugal pump of the type described above, if a hydrodynamically optimized centrifugal pump is selected, its nominal delivery capacity should therefore be chosen to be higher by the difference of the abovementioned delivery capacity. For the same nominal delivery capacity, the impeller outer diameter of the flushing centrifugal pump should be greater than the outer diameter of the hydrodynamically optimized centrifugal pump.

A specific solution for switching the basic idea of the present invention described above is that the rear and / or forward impeller gap, which must inevitably be between the impeller and the pump housing, is increased at most several times for these minimum front and rear impeller gaps, This consists in ensuring the mechanical function of the centrifugal pump by reducing the width of the impeller in the region of the front and rear impeller gaps. By expanding the impeller gap, the desired occurrence of the required flushing flow becomes possible first. The width of each of the front and rear impeller gaps can be calculated according to the specific characteristics of the liquid food.

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

Gapless cooling of the pump housing is achieved by providing, in addition to the housing cover side refrigerant space and the housing rear wall side refrigerant space, an inlet of the centrifugal pump projecting on the housing cover having the inlet connector side refrigerant space And is designed in the form of an inlet connector. This design is not essential from the perspective of the centrifugal pump according to the invention. Like the centrifugal pump intended for the formation of the inlet connector, the centrifugal pump is suitable for direct connection between the inlet connector of the centrifugal pump and the injection vessel provided at its bottom with a refrigerant space, which is out of the bottom, And then to the final end of the injection vessel. Next, the inlet connector can, in this arrangement, perform the function of a tubular section connected to the final outlet of the injection vessel. It is also possible to arrange with a centrifugal pump according to the invention, wherein the outlet port as the final end of the injection vessel is arranged directly on the housing cover of the centrifugal pump, where the formation of the inlet connector is intended.

In all designs, i.e. in the case of a centrifugal pump according to the present invention, with or without an inlet connector in combination with an inlet vessel in which the outlet or a tubular section connected thereto leads to the final end, the bottom of the vessel and the inlet to the centrifugal pump If applicable, the accumulation of heated liquid food in the connection area is undesirable. This accumulation is due to unwanted and unregulated residence times, which should be prevented. In connection with the injection container, the centrifugal pump according to the present invention has the purpose of immediately and completely discharging the heated liquid food accumulated in the injection container without clogging even in case of intermittent formation.

To enhance the flushing operation, each blade channel between two adjacent blades of the impeller is fluidically accessible in the region of its limited impeller rear side along with the rear impeller gap through one or more flushing bore holes penetrating the impeller rear side It is further proposed to be at the connection. Thereby, the radial depth involved in the associated flushing flow can be determined. In the most general case, the flushing boreholes include any type of passage opening; In other words, prototypes that are easy to produce are not essential.

The preferred design provides maximum extension to the forward impeller gap on the impeller outer diameter of the impeller and this extension provides a continuous reduction to the minimum forward impeller gap with the inlet in the largest blade channel. In this connection, 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 hydrodynamically optimized impeller. In the region of the front impeller gap, a second flushing flow is formed extending 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 enhanced, A third flushing flow is conceived.

Regarding the dimensions of the rear impeller gap, if the approach to the radially oriented minimum rear impeller gap starting from the impeller outer diameter of the impeller to the hub of the impeller is extended to a maximum of 5 mm by reducing the outer diameter of the impeller, Respectively. An advantageous expansion of the rear impeller gap according to the invention is also achieved in that an annular cutout cutout is applied to the rear side of the impeller in the region between the flushing bore hole and the hub of the impeller and its axial depth is at most 2 mm, 0.5 to 1 mm.

The positioning, forming design and dimensions of the flushing borehole are the characteristics in which the associated flushing flow is determined for its radial depth of engagement, its shaping and quantitative strength. If a single flushing borehole is placed in each blade channel, it is advantageous in terms of flow and production if all of these flushing boreholes are placed on a single hole circle with corresponding spacing.

With respect to the positioning of the flushing boreholes in the blade channel, the geometric position for each penetration point of the flushing borehole together 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 a distance of the blade at 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

Approximately through the center of the maximum flow filament length of the blade channel between its inlet and outlet

It has been found advantageous to be determined.

The flushing bore hole has a shape which is designed as a circular shape with a diameter of the bore hole or deviates from a circular shape having a hydraulic diameter related to this shape. The hydrodynamic diameter is a dimension known to be the cross-sectional area of the flushing bore hole and the quotient of four times the circumference of the flushing bore hole. It has been found that the diameter or hydraulic diameter of the borehole is advantageous when it is 30 to 50%, preferably 40 to 50% of the distance between the blades at the penetration point.

According to a further design, the present invention also provides one or more flushing bore holes in each blade channel, wherein each of several of the flushing bore holes of the blade channel is disposed on an associated hole circle, and the hole circles are spaced apart from one another. Accordingly, as the difference in the radial direction of the flushing borehole spaced from the rotation axis of the centrifugal pump decreases, the impact pressure difference in the flushing borehole increases, and as the diameter of the hole circle decreases, the cross- It helps to save space.

To ensure cooling that satisfies the special characteristics of the heated liquid food, the present invention provides a circuit of a refrigerant space as follows. According to the first proposal, the refrigerant is supplied to the inlet connector side refrigerant space, the housing cover side refrigerant space and the housing rear wall side refrigerant space, respectively, when they are currently applicable. The second proposal provides a design variant in which at least two of the aforementioned refrigerant spaces are connected in series with one another. It is provided according to the third proposal that the inlet connector side refrigerant space is an integral section with the housing cover side refrigerant space.

In order to make a prerequisite for the flushing operation of the rear and / or forward impeller gap, the present invention starts with a hydrodynamically optimized centrifugal pump, preferably a commercially available centrifugal pump, with the rear and front impeller gaps expanding Lt; / RTI > this is:

임펠러의 양방향 회전, 또는

Bi-directional rotation of the impeller, 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.

Which is axially extending in the direction of the pump shaft disposed between the housing cover and the housing rear wall, and the impeller is not offset relative to the housing back wall, or in the axial direction As shown in Fig.

The choice of the hydrodynamically optimized centrifugal pump for this purpose is made in relation to the difference in nominal delivery capacity described above between the flushing centrifugal pump and the hydrodynamically optimized centrifugal pump.

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

A more detailed description of the invention is made with reference to the appended claims, along with the following description and the annexed drawings. The present invention is realized in various designs of a general type of method, various embodiments of equipment for carrying out this method, and various embodiments of such centrifugal pumps for equipment, while the impeller according to the invention is housed in its pump housing A preferred exemplary embodiment of a centrifugal pump according to the present invention in fluid connection with an outlet of an injection vessel is described below with reference to the drawings.

During the treatment of the thermosensitive liquid food (P), it is ensured that the tendency of food contamination from the injection vessel and from there into the centrifugal pump is reduced, in particular the centrifugal pump is used for a considerably longer period of time than the hydrodynamically optimized centrifugal pump Life and ensure the mechanical function of the centrifugal pump.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a processing facility of a thermosensitive liquid food according to the prior art; FIG.
Figure 2 is a schematic representation of an injection vessel for direct heating of liquid food which is directly connected to a rotary displacement pump and is known in the prior art.
Figure 3 shows a centrifugal pump in a direction perpendicular to both the axis of rotation and the longitudinal axis of its pressure connector, the axis of rotation is oriented in the direction of gravity and the centrifugal pump is placed directly on the outlet of the vessel.
Fig. 4 is a front view showing the impeller of the centrifugal pump according to Fig. 3 together with an enlarged view of the first and third flushing flows S1 and S3. Fig.
Fig. 5 is a side view showing a meridional section through the impeller according to Fig. 4 along the cutting line marked AA along with a schematic view of the first and second flushing flows S1, S2. Fig.

A facility 1000 (e.g. WO 2011/101077 A1) according to FIG. 1 known in the art is known as a first type injection vessel 50 * (e.g. WO 2010/086082 A1) Container 50 has a product inlet 60 in its head space for centrally and annularly supplying liquid food P to be heat treated to the injection container 50 * of the first type through it. The first steam D 1 is supplied radially outward to the liquid food P supplied for direct heating through the outer steam inlet 62 and the second steam D 2 is supplied to the inside In the radial direction. The first type of injection vessel 50 * is connected to the bottom of the vessel 50 for the cooling (K) of the bottom of the first type injection chamber 50 * through the injector side refrigerant inlet 66, do. The discharge of the refrigerant is performed through the refrigerant outlet 68 on the injector side.

The outlet of the first type of injection vessel 50 * is connected to the first conveying apparatus 54 via an outlet pipe 52 surrounded by the outlet pipe side refrigerant space 52.1, , Is designed as a displacement pump, preferably as a rotary pump, and is arranged in a connecting line 70 leading from the first conveying device 54 to the entrance of the vacuum chamber 56. The first conveying device 54 conveys the heated liquid food P from the first type of injection container 50 * to the vacuum chamber 56. The vacuum chamber 56 is designed to remove any amount of water W as so-called vacuum steam from the heated liquid food (P) cooling by decompression, which is the first steam D1 and the second steam D2 In the present case, steam is supplied to the top of the first type injection container 50 * in the form of steam D, and is preferably switched through the steam outlet 72 disposed in the upper region. The liquid food P * processed in this way is conveyed through a second conveying device 58, which is preferably designed as a centrifugal pump, through a discharge line 74, which is disposed in the bottom region of the floor inclined in the middle, 56).

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

The position of the centrifugal pump 54 according to the present invention shown in Fig. 3 in which the rotational axis of the pump shaft 96 is oriented in the direction of gravity is determined by the centrifugal pump 54 through an inlet 76 designed as an inlet connector Which is suitable for direct connection to the outlet 50.3 at the bottom of the vessel 50.2 of the injection vessel 50 (which may be designed as a first or second type of injection vessel 50 *, 500) and then presents these designs . The injection vessel 50 is connected to the cylindrical vessel casing 50.1 preferably above the vessel bottom 50.2 which is tapered downward. A partial cross-section of the container bottom 50.2 and the container casing 50.1 connected thereto has a container side refrigerant space 50.4 which has a first refrigerant inlet 78 for refrigerant supply for cooling K1 of the bottom of the container, And a first coolant outlet (80) for discharge.

The centrifugal pump 54 is suitable for a special mode of transporting a thermally sensitive liquid food (P) such as milk protein concentrate, baby food, liquid baby food concentrate, nutritional beverage or milk used to make cheese, Into a connection line 70 leading to a vacuum chamber 56 and is discharged at an outlet 94 designed as a pressure connector. The centrifugal pump 54 also has a pump housing 12 of a known type formed by one or more housing covers 8 and a housing back wall 10. A pump chamber 98, which receives the impeller 100 (in this case, see FIGS. 4 and 5) in a rotating manner and is fluidly connected to the inlet 76 and the outlet 94, ). The tubular sections 52 and 76 are connected to an outlet 50.3 which may be formed by an outlet pipe 52 leading out of the injection vessel 50 or by an inlet connector 76 of the centrifugal pump 54 have. If the tubular sections 52, 76 are designed as an outlet pipe 52, they can be surrounded by the outlet pipe side refrigerant space 52.1; If this is designed as the inlet connector 76, it can be surrounded by the inlet connector side refrigerant space 76.1. In both cases, the refrigerant for cooling (K2) of the outlet pipe or inlet connector is supplied to the refrigerant spaces (52.1, 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 completely surrounds this 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 may have a housing rear wall side refrigerant space 10.1 which is preferably in contact with the housing rear wall 10 either fully or partially in the form of, for example, cooling pockets. The refrigerant for cooling (K4) of the rear wall of the housing is supplied to the 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, which are described in more detail in FIGS. 4 and 5, .

Figures 4 and 5 illustrate that the blades 2, which are preferably positioned vertically on the impeller rear side 4, are bent back from one plane and against the direction of rotation n (see Figure 4) And an impeller 100 that opens toward the housing cover 8 and closes toward the rear wall 10 of the housing by the impeller rear side 4 and a blade channel 2.1 is formed between the two adjacent blades 2, do. The rear bending blade is not an essential characteristic of the impeller 100 for the centrifugal pump 54 according to the present invention. A blade that is bent forward in the plane or simply radially oriented, or even a spatial bend, can be implemented without limitation in terms of realizing the flushing centrifugal pump 54 according to the present invention. The rear side RS of the impeller 100 mainly formed by the impeller rear side 4 is spaced from the rear 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 from the housing cover 8 by the front impeller gap s2.

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

The preferred embodiment is characterized in that the forward impeller gap s2 is maximally extended to the impeller outer diameter DL of the impeller 100 and is continuously down to the inlet region in the maximum blade channel 2.1 to the minimum forward impeller gap s2 * . 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 hydrodynamically optimized impeller.

A further preferred embodiment is characterized in that by approaching the radially oriented minimum impeller gap s1 * starting from the impeller outer diameter DL of the impeller 100 and extending to the hub of the maximum impeller 100, (DL) is reduced to a maximum of 5 mm, and thus the impeller 100 retracts slightly radially outwardly relative to the pump housing 12. Expansion of the rear impeller gap s1 is performed according to the present invention and is preferably performed in the region between the flushing bore hole 6 and the hub of the impeller 100 (see Fig. 5) on the impeller rear side 4, A face shape cutout 2.3 is applied, and its axial depth is at most 2 mm, preferably 0.5 to 1 mm. The dimensions of the rear and / or forward impeller gaps s1, s2 in the manner described above depend on the particular characteristics of the heated liquid food P and are preferably determined in the field test.

Each blade channel 2.1 between two adjacent blades 2 of the impeller 100 is connected to one of the blades 2 through its one or more flushing bore holes 6 through the impeller rear side 4, Lt; RTI ID = 0.0 > s1 < / RTI >

According to a preferred embodiment, these flushing boreholes 6 all have a diameter d of the hole circle in the case of a single flushing bore hole 6 in each blade channel 2.1, . The geometric position of each of the penetrating points of the flushing bore hole 6 together with the impeller rear side 4, which determines the diameter d of the hole circle, , Approximately through the center of the blade channel (2.1), and approximately the center of the maximum flow filament length of the blade channel (2.1) between its inlet and outlet.

The flushing bore hole 6 is preferably designed as a circle with a 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). Therefore, the diameter Db or the hydrodynamic diameter Dh of the borehole is 30 to 50%, preferably 40 to 50% of the distance from the blade 2 at the penetrating point.

The present invention further relates to a method of manufacturing a honeycomb structure in which one or more flushing bore holes 6 are provided in each blade channel 2.1 and several flushing bore holes 6 in the blade channel 2.1 are disposed on respective associated hole circles 2.2 , And the hole circle (2.2) are spaced radially from each other. The flushing bore holes 6 on the different hole circles 2.2 can have the same diameter Db or hydraulic diameter Dh or different diameters Db or the hydrodynamic diameter Dh from the hole circle to the hole circle Respectively. Due to the pressure differential decreasing radially inwardly between the rear wheel side space and the blade channel 2.1, the preferred embodiment is characterized in that the flushing bore hole 6 on the different hole circle 2.2, according to the decreasing diameter d of the hole circle, So that the cross-section of the passageway is smaller. Therefore, when the flushing volume flow is to be achieved, the borehole diameter Db or the hydrodynamic diameter Dh of the flushing bore hole 6 tends to become smaller toward the hub region of the impeller 100. [

There is provided at least a housing cover (8) having a housing cover side refrigerant space (8.1) through which the refrigerant can flow. If desired, the housing rear wall 10 can 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 refrigerant is supplied to the inlet connector side refrigerant space 76.1, the housing cover side refrigerant space 8.1 and the housing rear wall side refrigerant space 10.1 separately from each other. Another embodiment provides that at least two of the refrigerant spaces 76.1, 8.1, 10.1 are connected in series with one another. According to a further proposal, the inlet connector side refrigerant space 76.1 is an integral section with the housing cover side refrigerant space 8.1.

The following scheme in which a centrifugal pump according to the prior art is modified according to the invention ensures a combination of the flushing operation of the impeller 100 according to the invention with each other or individually with each other:

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

  The bidirectional rotation of the impeller 100, or

  Is extended by a spacer element acting in the axial direction in the direction of the pump shaft 96 which is arranged between the housing cover 8 and the housing rear wall 10 and the impeller 100 is supported by the housing rear wall 10 Is offset or offset axially in correspondence with the pump shaft 96 in the pump chamber 98.

- Arrangement of the above-mentioned flushing bore hole 6 in the manner described above.

Figures 4 and 5 illustrate the effects of the above measures in accordance with the present invention. By a widening of the rear impeller gap s1 or by respectively approaching thereto, a dominant positive pressure is provided on the outlet side of the impeller 2 in a somewhat unlimited manner in the associated rear wheel side space, And has an impeller outer diameter (DL). A static pressure lower than the rear wheel side space exists in each of the flushing bore holes 6 in the blade channel 2.1. As shown in FIGS. 5 and 4, the first flushing flow S1 radially inwardly directed from the inside is only one example of the latter, and by being present on the blade channel 2.1, (2.1) due to the flow penetration due to the causal relationship of the flushing bore hole (6) into the 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 if cooling of the housing rear wall K4 is provided if applicable, It is preferred that the permanently cooled liquid food (P) now enters the core region of the flow in the blade channel (2.1).

By virtue of the aforementioned expansion of the front impeller gap s2, as seen in the upper left quadrant of the impeller 100 in FIG. 4, as seen through the free forward edge of each forward side blade 2, It is possible to form the third flushing flow S3 over the direction extension region. The driving force for this third flushing flow S3 is caused by the static pressure on the upper side of the blade and the pressure difference in each blade 2 given by the static pressure on the suction side SS which is the bottom side of the blade. The third flushing flow S3 ensures a further movement in the circumferential direction relative to and in relation to the housing cover 8, and thus forced cooling of the liquid food P, which results in cooling of the housing cover K3 Is provided on the housing cover 8 (see Fig. 5). The third flushing flow S3 also causes here the exchange of liquid food in and out of the flow core zone in the associated blade channel 2.1. The second flushing flow S2 is formed through the expanded front impeller gap s2 due to the difference between the static pressure at the outlet of the impeller 100 and the static pressure at the inlet side inlet of the impeller 100, (See FIG. 5), which overlaps the third flushing flow S2. This second flushing flow S2 also ensures the exchange of liquid food P into and out of the flow core zone in the associated blade channel 2.1.

Exemplary Embodiment of Centrifugal Pump 54 According to the Invention:

The centrifugal pump 54 is driven by a drive motor having a nominal capacity of 15 kW at a nominal speed n = 2900 / l. 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 and this reduction continues in succession down to the minimum forward impeller gap s2 * with the inlet region into the blade channel 2.1. The rear impeller gap s1 extends by 0.7 mm in the region of the annular planar cutout (2.3) with respect 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 designed in a circular shape and has a borehole diameter Db of 10 mm.

The above-described measures according to the invention are applicable in a manner similar to a closed impeller, and in the manner described hereinafter, the third flushing flow S3 through the front-side rim of each blade 2 is not possible Do. As an alternative to such a flushing path, the cover plate of the impeller 100 is then formed between the cover plate and the housing cover 8, with an additional flushing bore hole, each connecting an associated blade channel to the front wheel side space . Next, a flushing flow suitable for the first flushing flow S1 described above takes place.

Figures 1 and 2 (prior art)
1000 facilities
50 Injection vessel full
50 * First type injection container
500 second type injection container
50.4 Refrigerant space on the bottom of container
52 Outflow pipe
52.1 Refrigerant space on outlet pipe side
54 First conveying device
540 Rotational Displacement Pump
56 Vacuum chamber
58 Second conveying device
60 Product entrance
62 Outside steam inlet
64 Inside steam inlet
66 Inlet side refrigerant inlet
67 Pump side refrigerant inlet
68 Injector side refrigerant outlet
70 connecting lines
72 steam outlet
74 (for processed food) Discharge line
D steam
D1 First Steam
D2 second steam
K cooling
P liquid food
P * processed food
W water
3
50 injection container
50 * First type injection container
500 second type injection container
50.1 Container casing
50.2 Container bottom
50.3 Outlet
50.4 Refrigerant space on the bottom of container
8 Housing cover
8.1 Refrigerant space on the housing cover side
10 Barrier after housing
10.1 Refrigerant space on the side of the wall behind the housing
12 Pump housing
54 Centrifugal pumps
76 Inlet (inlet connector)
76.1 Refrigerant space on inlet connector side
78 1st refrigerant inlet
80 first refrigerant outlet
82 second refrigerant inlet
84 second refrigerant outlet
86 third refrigerant inlet
88 third refrigerant outlet
90 fourth refrigerant inlet
92 fourth refrigerant outlet
94 Outlet (pressure connector)
96 Pump shaft
98 pump chamber
100 impeller
Cooling of K1 container bottom
Cooling of K2 outlet pipe or inlet connector
Cooling of K3 housing cover
K4 Cooling of rear wall of housing
S1 First flushing operation
S2 second flushing operation
S3 third flushing operation
4 and 5
2 blades
2.1 blade channel
2.2 holes
2.3 Annular face contour cutout
4 Impeller rear side
6 Flushing bore hole
DL impeller outer diameter
Diameter of Db bore hole
Dh Hydraulic diameter
DS pressure side (blade)
RS rear side (impeller)
SS inlet side (blade)
VS front side (impeller)
Diameter of the hole circle
s1 rear impeller gap
s1 * Minimum rear impeller gap
s2 forward impeller gap
s2 * Minimum front impeller gap
n rotation direction

Claims (38)

The liquid food P is directly heated by the steam D to form a sterilized state in the injection vessel 50 (50 *, 500), and the amount of the steam D previously supplied by the reduced pressure to a lower pressure Is removed from the liquid food (P), and the liquid food (P) is conveyed between the heating and the reduced pressure by the first conveying device (54) designed as a centrifugal pump P), the following processing steps (a) to (e), namely:
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 therein;
(b) a tubular section (52, 76) directly connected to an outlet (50.3) formed by the outlet pipe (52) leading to the injection vessel (50; 50 *; 500) or the inlet connector Gt; (K2) < / RTI >
(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) a portion of the volume flow configured to be carried in the impeller 100 of the centrifugal pump 54 and open to the housing cover 8 of the centrifugal pump 54, One of the pump housing 12 and one of the impellers 100 is connected via the rear impeller gap s1 provided between the impeller 100 and the front impeller gap s2 provided between the housing cover 8 and the impeller 100, The volumetric flow of the planned flushing operation is at most several times greater than the unavoidable equalization flow in the pump housing 12, which results in the minimum rear and front impeller gaps (s1 *, s2 Wherein the centrifugal pump (54) has a hydrodynamically optimized design of the centrifugal pump (54) and ensures the mechanical function of the centrifugal pump (54). The method according to claim 1,
Characterized in that the fourth cooling (K4) is performed in the housing rear wall (10) of the pump housing (12) for the liquid food (P). 3. The method according to claim 1 or 2,
Characterized in that the first and second flushing operations (S1 and S2) are respectively generated by recirculation through the impeller (100) driven by the pressure difference in the pump housing (12) Processing method. The method of claim 3,
The first flushing operation S1 is carried out through a rear impeller gap s1 between the impeller 100 and the housing rear wall 10 and the first flushing operation S1 is carried out through the impeller 100, (P). ≪ / RTI > The method according to claim 3 or 4,
The second flushing operation S2 is performed through the front impeller gap s2 between the housing cover 8 and the impeller 100 and the second flushing operation S2 is performed through the impeller 100 (P). ≪ / RTI > 6. The method according to any one of claims 1 to 5,
Characterized in that the third flushing operation (S3) is carried out by equalizing flow between each pressure side and the inlet side of the blade (2) of the opened impeller (100) and through the forward impeller gap (s2) (P). 7. The method according to any one of claims 2 to 6,
Characterized in that the cooling (K1, K2, K3, K4) are operated separately from each other. 7. The method according to any one of claims 2 to 6,
Characterized in that at least two of the cooling (K1, K2, K3, K4) are connected in series. 9. The method according to any one of claims 2 to 8,
Characterized in that the cooling (K1, K2, K3, K4) is operated in countercurrent to the heated liquid food (P). In the processing facility 1000 for the thermosensitive liquid food (P)

An injection vessel (50; 50 *, 500) for directly heating liquid food (P) with steam (D) to form a sterilized state;

Is connected in fluid connection with the injection vessel (50; 50 *, 500) via a connecting line (70), and the amount of water W) is removed from the liquid food (P);

A first delivery device 54 disposed in the connection line 70 and designed as a centrifugal pump for delivering 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;

Is connected to the outlet 50.3 for delivery of the heated liquid food P and is connected by an inlet connector 76 of the outlet pump 52 or centrifugal pump 54 leading out of the injection vessel 50 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 the heated liquid food P flowing through the tubular sections 52 and 76;

A pump housing (not shown) of a centrifugal pump 54 formed by at least the housing cover 8 and the housing rear wall 10 and having a housing cover side refrigerant space 8.1 for cooling the heated liquid food P to be conveyed 12); And

A portion of the volumetric flow of the heated liquid food P carried to the impeller 100 by the centrifugal pump 54 having the impeller 100 opened to the housing cover 8 causes the pump housing 12 and the impeller 100 to rotate, One or more projected flushing operations of the impeller 100 are carried out by 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 , And the volumetric flow of the planned flushing operation is at most several times larger than the unavoidable equalization flow in the pump housing 12, which in each case has the minimum rear and front impeller gaps (s1 *, s2 *) A processing facility for a thermally sensitive liquid food (P) comprising a centrifugal pump (54), which is due to the hydrodynamically optimized design of the centrifugal pump (54) and designed to ensure the mechanical function of the centrifugal pump (54). 11. The method of claim 10,
Characterized in that the pump housing (12) has a housing rear wall side refrigerant space (10.1). The method according to claim 10 or 11,
The first flushing operation S1 is performed through the rear impeller gap s1 between the impeller 100 and the housing rear wall 10 through the at least one flushing bore hole 6 disposed on the impeller rear side 4 (P). ≪ / RTI > 13. The method according to any one of claims 10 to 12,
Wherein a second flushing operation (S2) is performed through a front impeller gap (s2) between the housing cover (8) and the impeller (100). 14. The method according to any one of claims 10 to 13,
Characterized in that a third flushing operation (S3) is performed by equalization flow between each pressure side and the inlet side of the blade (2) of the opened impeller (100) and through the forward impeller gap (s2) (P). 15. The method according to any one of claims 11 to 14,
Refrigerant is separately supplied to the container bottom side refrigerant space 50.4, the outlet pipe side or the inlet connector side refrigerant spaces 52.1 and 76.1, the housing cover side refrigerant space 8.1 and the housing rear wall side refrigerant space 10.1, respectively (P). ≪ / RTI > 15. The method according to any one of claims 11 to 14,
Characterized in that at least two of the refrigerant spaces (50.4, 52.1, 76.1, 8.1, 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, An impeller 100 having a bladder 2 rotatably received in the pump chamber 98 and a pump chamber 98 fluidly connected to the housing cover 8 and 94 and open to the housing cover 8, A blade channel 2.1 designed between two adjacent blades 2 that are closed by the impeller rear side 4 towards the impeller 100 and 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), the centrifugal pump (54)

The rear and / or forward impeller gaps s1 and s2 are extended by a maximum of several times with respect to this type of minimum rear and front impeller gaps s1 * and s2 *, so that in the region of the rear and front impeller gaps s1 and s2 By reducing the width of the impeller 100, the mechanical function of the centrifugal pump 54 is ensured,

Characterized in that at least the housing cover (8) has a refrigerant space (8.1) in which the refrigerant can flow, the centrifugal pump carrying the thermosensitive liquid food (P). 18. The method of claim 17,
Characterized in that the housing rear wall (10) comprises a refrigerant space (10.1) through which the refrigerant can flow. 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 projecting on the housing cover 8, and the inlet connector side refrigerant space 76.1 (P), characterized in that the heat-sensitive liquid food (P) is conveyed. 20. The method according to any one of claims 17 to 19,
Each of the blade channels 2.1 is connected in fluid connection with the rear impeller gap s1 in the region of the adjacent impeller rear side 4 through one or more flushing bore holes 6 penetrating the impeller rear side 4 A centrifugal pump for conveying a thermosensitive liquid food (P). 21. The method according to any one of claims 17 to 20,
The maximum expansion is applied to the front impeller gap s2 on the impeller outer diameter DL of the impeller 100 and is continuously reduced to the minimum forward impeller gap s2 * into the region of the inlet in the blade channel 2.1 Centrifugal pump for transporting thermosensitive liquid food (P). 22. The method of claim 21,
Characterized in that the reduction of the width of the impeller (100) on the impeller outer diameter (DL) is 40 to 55% of the width of the hydrodynamically optimized impeller. 23. The method of claim 22,
Characterized in that the reduction is 50 to 55% of the width of the hydrodynamically optimized impeller (100). 24. The method according to any one of claims 21 to 23,

The approach to the radially oriented minimum rearward impeller gap s1 * starting from the impeller outer diameter DL of the impeller 100 and extending to the hub of the impeller 100 is achieved by reducing the impeller outer diameter DL to a maximum of 5 mm Extended,

The expansion of the rear impeller gap s1 consists of applying an annular side cutout 2.3 to the impeller rear side 4 in the region between the flushing bore hole 6 and the hub of the impeller 100, Characterized in that the axial depth of the gap is at most 2 mm. 25. The method of claim 24,
Wherein the axial depth of the cutout (2.3) is 0.5 to 1 mm. 26. The method according to any one of claims 20 to 25,
Characterized in that in the case of a single flushing bore hole (6) in each blade channel (2.1), these flushing bore holes (6) are all arranged on a single hole circle (2.2) ). 27. The method according to any one of claims 20 to 26,
The geometric 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 distance of the blade 2 at the point of penetration, approximately through the center of the blade channel 2.1, and

Is determined through the center of the maximum flow filament length of the blade channel (2.1) approximately between its inlet and outlet. 28. The method according to any one of claims 20-27,
Characterized in that the flushing bore hole (6) is designed circular in diameter (Db) of the bore hole. 29. The method according to any one of claims 20 to 28,
Characterized in that the flushing bore hole (6) has a shape deviating from a circle having a hydraulic diameter (Dh) related to this shape. 30. The method of claim 28 or 29,
Characterized in that the diameter (Db) or the hydraulic diameter (Dh) of the borehole is 30% to 50% of the distance between the blades (2) at the penetration point. 31. The method of claim 30,
Characterized in that the diameter (Db) or the hydraulic diameter (Dh) of the borehole is 40 to 50% of the distance between the blades (2) at the penetration point. 32. The method according to any one of claims 20 to 31,

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

The various flushing bore holes 6 of the blade channel 2.1 are each disposed on an associated hole circle 2.2,

Characterized in that the hole circles (2.2) are spaced radially from each other. 33. The method of claim 32,
Characterized in that the passage sectional area of the flushing bore hole (6) on the different hole circle (2.2) is reduced as the diameter (d) of the hole circle is reduced. 34. The method according to any one of claims 19 to 33,
Characterized in that refrigerant is supplied to the inlet connector side refrigerant space (76.1), the housing cover side refrigerant space (8.1) and the rear wall side refrigerant space (10.1) of the housing separately from each other. Pump. 34. The method according to any one of claims 19 to 33,
Characterized in that at least two refrigerant spaces of the refrigerant spaces (76.1, 8.1, 10.1) are connected in series with each other. 37. The method according to any one of claims 19 to 35,
Characterized in that the inlet connector side refrigerant space (76.1) is an integral section with the housing cover side refrigerant space (8.1). 37. The method according to any one of claims 17 to 36,
Beginning with a hydrodynamically optimized centrifugal pump, the rear and / or forward impeller gaps (s1, s2) are:

Bi-directional rotation of the impeller 100, or

Is extended by a spacer element axially acting in the direction of the pump shaft 96 disposed between the housing cover 8 and the housing rear wall 10 so that the impeller 100 is offset relative to the housing rear wall 10 Or is axially offset in correspondence with, or corresponding to, the pump shaft (96) in the pump chamber (98). Which is rotatably received in the pump chamber 98 of the centrifugal pump 54 and is designed between two adjacent blades 2 and which is closed toward the impeller rear side 4, (100) for a centrifugal pump (54) having a blade channel (2.1) designed to open at an inlet
Each blade channel (2.1) has at least one flushing bore hole (6) penetrating the impeller rear side (4) in the region of its adjacent impeller rear side (4)
At the front side (VS) of the impeller 100, the reduction in the width of the impeller 100 on the impeller outer diameter DL is 40 to 55% of the width of the hydrodynamically optimized impeller,
The reduction continues down to the associated width of the hydrodynamically optimized impeller with the inlet region into the blade channel 2.1,
Wherein the impeller outer diameter (DL) is reduced by at most 10 mm with respect to the outer diameter of the hydrodynamically optimized impeller.

Images