DK2658656T3

DK2658656T3 - Full cap screw centrifuge with overflow tuning

Info

Publication number: DK2658656T3
Application number: DK11794487.6T
Authority: DK
Inventors: Stefan Terholsen
Original assignee: Gea Mechanical Equipment Gmbh
Priority date: 2010-12-27
Filing date: 2011-12-13
Publication date: 2018-05-07
Also published as: DE102010061563A1; EP2658656B1; WO2012089492A1; EP2658656A1

Abstract

The invention relates to a solid bowl screw centrifuge having at least one device (23') for discharging clarified liquid out of a drum (3), a. wherein the device (23') has at least one or more through-passage openings (15) in a drum lid (17), b. wherein preferably the at least one through-passage opening (15) is assigned in each case a weir plate (19) which has and forms in each case an overflow weir (21) at its radial inner edge, c. wherein the weir plate (19) has a material cutout which forms at least a part of a discharging channel (25) or an entire discharging channel (25), and d. wherein the discharging channel (25) is formed such that it deflects a flow emerging from the drum at an angle > 0° with respect to the rotational axis.

Description

The invention relates to a solid-bowl screw centrifuge according to the preamble of Claim 1.

Solid-bowl screw centrifuges are known in various embodiments. DE 102 03 652 B4 discloses a solid-bowl screw centrifuge with a device for the discharge of clarified liquid from a drum, which has a drum cover with a passage, which a throttle device, especially a throttle plate is assigned to, the distance of which to the passage can be varied. Thereby, furthermore, nozzles are assigned to the passage to discharge the clarified liquid, which are aligned at an inclination towards the radial direction through the drum axis to save energy.

Nozzles on solid-bowl screw centrifuges and their energy-saving effect when aligned at an inclination to the drum axis are known from DE 39 04 151 Al.

In contrast, the publication "Patent Abstracts of Japan", number 11179236 A, discloses that baffles can be assigned to passage openings in the drum cover, which are each partially sealed by a weir plate, which form an overflow weir. The baffles swirl the liquid emerging from the drum, wherein the occurring rebound effect should be utilised to save energy. The baffles are affixed to the outside of the overflow weir, for example, attached to the weir plates. For example, they are designed as level sheets, which are aligned in parallel to the rotary axis of the drum, wherein the level at which the level sheets are located does not intersect with the drum axis and, more or less, form an angle of approximately 45° to the linear slope running in the radial direction, which respectively runs through the rotary axis of the drum and the respective passage opening.

It is also known - from US 2004/0072668 Al or WO 2008/138345 Al - to assign a housing instead of an overflow weir on the weir plate of the passage opening, wherein the overflow weir or a nozzle are formed at the passage opening on a sloping side of the housing. However, these constructions have the disadvantage that, on the outside of the drum cover, co-rotating, relatively complicated shaped liquid chambers are formed, which form part of the rotating system so that the clarification or separation process continues. Consequently, unwanted deposits may form in the chambers, which are associated with cleaning problems and balancing problems.

Concerning the technological background, with respect to Claim 1, JP 2009 136790 A, JP 56 129842 U and, with respect to Claim 14, DE 38 22 983 A1 will still be mentioned, wherein the latter publication discloses discharge openings in the drum cover section by section, which are obliquely inclined towards the axis of rotation, which should induce a fluid phase in the drum from the outside leading inward towards a discharge weir.

Using the most recent background art as a basis, the object of the invention is to create an optimised solid-bowl screw centrifuge with regard to saving energy, which can also be deemed beneficial with regard to the perspective of hygiene.

The invention achieves this task by means of the objects of Claims 1 and 13.

Some special advantages of the claimed and described embodiments have been compiled in the following.

Initially, a main advantage of the various embodiments with discharge channels will be described. In the case of a passage opening with a complicated design, liquids with fibrous solid contents can lead to the problem that the fibres get stuck in the grooves provided for the holder of the weir plate when emerging from the housing at certain areas. This can happen in particular during shutdown procedures, when the liquid ring suddenly collapses due to centrifugal forces that are too weak, however subject to a constant gravitational force, and the drum spontaneously empties. Particularly in housings that are utilised as a device to discharge liquid, as they have been suggested in various ways in the most recent background art, product deposits can easily form, since a stratification flow close to the surface forms, which cannot flush the solids from the areas of the housing that are located away from the centre. Due to the open design of discharge channels, the above-mentioned disadvantages are avoided.

According to the suggested new devices for the discharge of liquid from the centrifuge drum, deposits are also avoided since the liquid flows across the entire liquid cross section and therefore also in the proximity of the discharge element’s wall, thereby taking solid particles along with it in this way. This is an advantage from a sanitary perspective, but also on a constructional level with regard to the reduced risk of forming potential unbalances deriving from a deposited solid, which is not rotationally symmetrical. Such unbalanced solid deposits can form (as well as in other ways) if the centrifuge is stopped and solids are rinsed out unsymmetrically through the collapsing liquid ring due to the coincidental standstill position of the rotor or also if the solid itself flows out of the discharge element in an unsymmetrical manner.

Furthermore, concerning the variants of the invention with the open discharge channel, it is beneficial that the present invention leaves the overflow weir directly on the weir plates on the drum cover and the fluid, which has already left the rotating system via the overflow weir, is initially diverted into the circumferential direction. After flowing out of the drum, the clarifying effect can no longer occur, the entire emerging fluid stream is rather redirected into the circumferential direction by the deflection device.

It is furthermore beneficial that it is also avoided by means of the selected structures that the fluid held in the housing does not exert too much undesired additional centrifugal force on the drum. In particular, the discharge channels cannot fill with fluid; only a relatively thin fluid layer forms that only exerts a small amount of additional force in comparison.

Due to extending one or both elements, “base wall” and “one or both side walls” with the above-mentioned inclination in the direction of the rotational centre, it can be ensured that the deviation of the fluid flowing out from the ideal tangential direction is minimised.

The inclined passage openings in the front-side drum wall combined with a weir plate without a discharge element or a weir plate, which has a “grooved” contour and, in particular, the insert embedded into the drum wall have the advantage that the construction space required in the axial direction for the rotor is relatively small. By means of this, the material use for the rotor, the rack carrying the rotor as well as the housing surrounding the rotor can be minimised. In addition, the bearing distance is shortened, whereby higher rotational speeds of the centrifuge can be achieved due to the improved machine-dynamic characteristics since the rotational-speed-limiting natural frequencies shift to higher values.

The design with the drum insert embedded into the drum wall offers the advantage that inner contour adaptations regarding production characteristics and also operating parameters, such as the throughput capacity, are possible without making changes to the drum wall. In addition, the inserts can be easily replaced.

Other advantageous embodiments can be found in the rest of the subclaims.

In the following, the invention is described in detail taking the drawing into consideration. In the figures:

Fig. 1 a schematic view of a known solid-bowl screw centrifuge; and

Fig. 2-14 various views, cross sectional views and embodiments of devices for the discharge of liquid from a centrifuge drum, designed on a drum cover of a centrifuge drum. A schematic illustration of a coordinate system is partially assigned to the figures in the following, in the centre point of which the axis of rotation D of a centrifuge drum lies and in which the arrow U marks the rotational direction of the centrifuge drum. The line D' marks a parallel plane to the axis of rotation D and the arrow R shows the radial direction perpendicular to the axis of rotation D.

Initially, Fig. 1 should illustrate the basic construction of a solid-bowl screw centrifuge. The drive in addition to the control system, a cover and other elements that are self-evident to a person skilled in the art are not shown here.

Fig. 1 shows a solid-bowl screw centrifuge 1 with a drum 3, which can be rotated around axis of rotation D that is preferably horizontal, in which rotatable screw 5 is also arranged. The drum 3 and the screw 5 each have a section that is primarily cylindrical and a section that conically tapers here in a conical manner.

An axially extending centric feed pipe 7 is used for feeding the centrifuge material by way of a distributor 9 into the centrifuging chamber 11 between the screw 5 and the drum 3.

If, for example, muddy slurry is introduced into the centrifuge, courser solid particles deposit on the drum wall. A liquid phase forms further inwards.

The screw 5 rotates at a slightly lower or higher speed than the drum 3 and conveys centrifuged solid matter towards the conical section to a solid matter outlet 13 and out of the drum 3.

The liquid flows against it to the larger drum diameter on the back end of the cylindrical section of the drum 3 and is discharged via a weir, which as passage openings 15 in a drum cover 17, wherein a weir plate 19 is assigned to each passage opening 15, which is attached here on the outside of the drum cover in a radially adjustable manner. Thereby, the inner radial edge of the weir plate defines an overflow edge and hence also the actual weir or the overflow weir 21. In Fig. 1, the passage opening 15 and the weir plate 19 with the overflow weir 21 form a "device 23 for the discharge of fluid from the centrifuge drum" in their interaction. It is preferably provided to not only provide one of these devices 23 on the drum cover, but to distribute a plurality of these devices in a circumferential direction on at least one radius respectively.

Preferably, all of the aforementioned variants are complimented in a beneficial manner by a radial adjustability of the weir plates 19. This adjustability can, for example, also be implemented easily via hole patterns 37 (see Fig. 5) with selectable radial holes or bore holes on the weir plate and corresponding bore holes on the drum cover and bolts, or the like, in order to make simple adjustment of the fluid level diameter within the drum possible. For the sake of simplicity, the hole patterns are only shown in Fig 5, but are preferably provided in the case of all embodiments.

According to the invention, for example, in the case of a solid-bowl screw centrifuge according to the type shown in Fig. 1, the drum cover and/or the at least one device 23 to discharge liquid from the centrifuge drum can be replaced by a corresponding device 23' in Fig 2 to 14.

Initially, the exemplary embodiment in Fig. 2 to 4 are described.

Fig. 3 and 4 show top views of two different devices 23' and Fig. 2 shows a section through a corresponding device 23'. Each has to do with modified devices 23' for discharging liquid from a centrifuge drum, which, in contrast, have one or a plurality of passage opening(s) 15 in a drum cover 17 as components on a certain radius outside of the axis of rotation D and, as well as a weir plate 19 partially or fully covering the assigned passage opening 15.

The devices 23' furthermore each have one discharge channel 25, which is formed on the respective weir plate 19 and/or formed with it as a single piece.

The weir plate 19 in Fig. 2 to 4 leans on the drum cover 17 directly outside on the drum cover 17 aligned in parallel.

The weir plates 19 in Fig. 2 each have material recess 27 releasing the passage opening 15 "again" radially towards the outside towards the centre of rotation D.

Thereby, the weir 21 is laid in this area on a radius R27 lying further outside on the base of the recess.

The material recess 27 preferably protrudes into the discharge channel 25 on the outside of the weir plate 19. Thereby, it itself forms the beginning of the discharge channel 25.

The discharge channel 25 can (see Fig. 5 for more information) also only be composed of the material recess 27 if the weir plate 19 is thick enough and the material recess is aligned at an inclination angle γ (see Fig. 6) to the direction of rotation U. Preferably, however, the material recess is extended by a channel element 29 extending the weir plate on its side facing away from the drum 1.

The discharge channel is designed to be open at least on its side radially pointing inwardly 25, as well as preferably also on its end facing away from the weir plate 19.

The discharge channel has side diverting walls 31a, 31b, which can be designed to be level or curved into each other.

The cross section of the discharge channel 25 - see Fig. 2 for example - can be designed in various ways. It is important that the discharge channel 25 is preferably fully radially open towards the inside towards the axis of rotation D (in particular, in the direction of the emerging liquid’s flow). Particularly the fully open construction facing inward is susceptible to soiling, wherein the soiling tendency can be further reduced by rounding off the edge areas of the discharge channel 25.

The cross section of the discharge channel 25 can be designed to be polygonal (Fig. 3) or rather rounded (Fig. 4). The cross section can be constant across the length of the drainage channel or change.

According to Fig. 5 and 6, the discharge channel 25 is formed in a particularly easy and inexpensive manner on a constructional level, as well as, in turn, in a way that is not susceptible to soiling, by means of each of the weir plates 19 not having an extending channel element 29, but by means of simply providing the material recess 27 on the weir plate, the side walls 31a, 31b of which are not axially aligned, but curved or inclined against the direction of rotation in order to divert the emerging flow against the direction of rotation in this way. The weir plates 19 in Fig. 5 and 6, for the sake of simplicity, are also referred to in the following as "grooved" weir plates 19 due to their embodiment.

In the case of devices to discharge liquid 23' in Fig. 2 to 4 with a "polygonal" or "rounded" discharge channel 25, this lies "inside and outside" of the weir plate 19; in the case of the "grooved" weir plate 19 in Fig. 5 and 6, in contrast, the discharge channel 25 is formed "inside” of the weir plate 19.

The overflow weir 21 of the embodiments according to Fig. 2 to 6 is located at the entry point of the liquid into the material recess 27 of the weir plate 19, which thereby determines the diameter of the fluid level in the drum.

According to Fig. 2 to 6, the base wall 35 of the channel 25 runs in a straight line in the tangential direction.

The discharge of liquid from the channels is inclined at an angle β to the axis of rotation D with > 0° and β, preferably >= 20° and at an angle γ relative to the direction of rotation U. For the angle γ, preferably, the following applies: γ >= 0° and γ < 90° and especially preferably: γ >= 0° and γ < 30°. This embodiment is preferred.

As an alternative, it is however also conceivable that the angle γ is smaller than 0°, for example, also smaller than -30° (not shown), even if a discharge of the liquid phase takes place in the direction of the drum cover.

However, it is also conceivable that the depth of the channel(s) 25 change (particularly with relation to the level corresponding to Fig. 2; not shown). Fig. 7 and 8 show further embodiments of outlet elements, which have drainage channel 25 which is radially open inwardly.

According to Fig. 7 and 8, it is provided as an example that the channel element 29 of the discharge channel has a shape that runs concentrically on a circular arc section with a constant radius. Therefore, in particular, the base wall 35 has a shape that is fully rounded or rounded in sections, running concentrically to the centre of rotation.

While Figs. 2 to 8 concern embodiments where discharge channels 25 are formed, which are fully open on one side in a weir plate 19 and preferably also in an axial channel-like extension - channel element 29 - of the weir plate 19, it is also conceivable to divert the liquid flowing out of the drum 1 into the circumferential direction by means of the drum cover itself having passage openings 15, which do not extend in the axial direction, but which are inclined at angle β relative to the longitudinal axis D of the drum. The passage openings 15 are therefore somewhat cylindrical for example, aligned obliquely to the axis of rotation, wherein the angle δ between the axis of rotation D and the centre axis of the passage openings 15, is, in any case, larger than 0° and smaller than 90° section by section.

Preferably, this applies to the inclination angle δ: δ >= 20° and δ <= 60° (Fig. 9 and 10). As an alternative, the passage opening can also be designed curved into itself. Mixed forms of the described embodiments can in any case be implemented.

Each of the "inclined" passage openings 15 is preferably covered by a corresponding weir plate 19 up to a predefined radius. Thereby, this covering weir plate 19 can itself have a "straight" overflow edge or weir edge 21, which is at a predefined radius or one that can be preferably adjusted by means of hole patterns or the like. Preferably, it is furthermore conceivable to combine the "inclined" passage openings with weir plates 19 according to the type in Fig. 2 to 8, meaning with weir plates which have a type of discharge channel 25, at least in the form of a channel contour in order to achieve an especially advantageous discharge behaviour in this manner.

In this way, Fig. 11 and 12 show embodiments with inclined passage openings 15 in the front-side drum wall 17 and weir plates 19 which have a "grooved" and bevelled contour according to the type shown in Fig. 6 or 7.

Fig. 13 furthermore shows an embodiment, which beneficially combines the inclined passage openings 15 in the front-side drum wall 17 with one of the weir plates 19 with a channel element 29 respectively according to the type shown in Fig. 2 or 3.

Furthermore, Fig. 14 illustrates the possibility to use inserts 41 into the passage openings 15 of the drum cover, for example, screw inserts, which are screwed into the screw holes of the drum cover 17, wherein the inserts themselves can be inserted into the axial bore holes of the drum cover and then, in contrast, can have bore holes 43 that are aligned at an inclination to the drum axis D or D’.

Fig. 14 shows a variant, where bore holes 43 running parallel to the longitudinal axis D of the drum are formed in the front-side drum wall, which are each provided with an insert 41, which has a bore hole 43 in its interior space, the centre axis of which forms an angle of δ: δ >= preferably 15° and δ <= preferably 75° to the direction of rotation U of the drum (Fig. 14).

The inserts 41 in the drum wall or in the drum cover can be designed in various ways.

In this way, the axial extension of the insert 41 can correspond to the axial thickness of the drum wall and the axial thickness of the drum cover (Fig. 14).

Theoretically, a variant of the insert 41 can also be implemented, where this, for example, protrudes across the front side of the drum (not shown) with a plate-like flange section or the like. In addition, an insert 41 in the drum wall- such as has been described in the above, with a sluice edge (not shown) is also conceivable.

It is especially advantageous to have the combination of the insert 41 in the drum wall according to the type shown in Figure 14 in combination with a device 23' according to Figs. 2 to 5, meaning with a weir plate according to one of the preceding Figs. 1 to 13.

Reference list

Solid-bowl screw centrifuge 1

Drum 3

Screw 5

Feed pipe 7

Distributor 9

Centrifugal chamber 11

Solids discharge 13

Passage openings 15

Drum cover 17

Weir plate 19

Overflow weir 21

Device for the discharge of liquid 23, 23'

Discharge channel 25

Material recess 27

Channel element 29

Diverting walls 31a, 31b

Base wall 35

Hole patterns 37

Inserts 41

Bore holes 43

Outer side 45

Radius R27

Radial direction R

Direction of rotation U

Rotary axis D

Parallel to D D'

Inclination angle α, β, δ, γ

Directions x, y

Claims

1. Fuldkappe-skruecentrifuge med i det mindste en indretning (23’) til bortledning af klaret væske fra en roterbar tromle (3), a. hvorved indretningen (23’) i det mindste omfatter en eller flere gennemgangsåbninger (15) i et tromledæksel (17), b. hvorved der til den i det mindste ene gennemgangsåbning (15) er knyttet en respektiv overløbsplade (19), som på sin respektive, radiale inderkant omfatter og danner et omløbsstemmeværk (21), kendetegnet ved, at c. overløbspladen (19) omfatter en materialeudsparing, som i det mindste danner en del af en afløbsrende (25) eller en hel afløbsrende (25), d. hvorved afløbsrenden (25) er udformet således, at den fra tromlen udgående strømning omstyres mod en rotationsretning og ved en vinkel β > 0° og β < 90° i forhold til rotationsaksen og ikke i retning af tromledækslet.A full-cap screw centrifuge with at least one device (23 ') for draining clear liquid from a rotatable drum (3), a. Wherein the device (23') comprises at least one or more through-openings (15) in a drum cover (17), b. Attaching to said at least one passage opening (15) is a respective overflow plate (19) which, on its respective radial inner edge, comprises and forms an orbital tuning device (21), characterized in that c. (19) comprises a material recess which forms at least a portion of a drainage channel (25) or a whole drainage channel (25), d. Wherein the drainage channel (25) is designed so as to direct the flow from the drum to a direction of rotation and at an angle β> 0 ° and β <90 ° relative to the axis of rotation and not in the direction of the drum cover.

2. Fuldkappe-skruecentrifuge ifølge krav 1, kendetegnet ved, at materialeudsparingen (27) på den bort fra tromlens indre vendende yderside (45) af overløbspladen (19) fortrinsvis flugtende går over i et rendeelement (29), der er påsat på eller dannet integreret med rendeelementet (29), således at afløbsrenden (25) dannes af materialeudsparingen (27) og rendeelementet (29).Full-face screw centrifuge according to claim 1, characterized in that the material recess (27), preferably away from the inner surface (45) of the overflow plate (19), preferably flushes into a gutter element (29) mounted on or formed integral with the gutter element (29) so that the drain gutter (25) is formed by the material recess (27) and the gutter element (29).

3. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at afløbsrenden (25) er udformet som åben, i det mindste på sin radialt indad vendende side.Full cover screw centrifuge according to any one of the preceding claims, characterized in that the drain channel (25) is formed as open, at least on its radially inwardly facing side.

4. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at afløbsrenden (25) er udformet som åben på sin bort fra overløbspladen (19) vendende ende.Full-cap screw centrifuge according to any one of the preceding claims, characterized in that the drain channel (25) is formed as open at its end facing away from the overflow plate (19).

5. Fuldkappe-skruecentrifuge ifølge et eller flere af de foregående krav, kendetegnet ved, at rendeelementet (29) er udformet som helt eller afsnitsvist åben radialt indad.Full cover screw centrifuge according to one or more of the preceding claims, characterized in that the gutter element (29) is formed as a whole or sectionally open radially inward.

6. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at afløbsrenden (25) omfatter sideværts omstyringsvægge (31a, 31b), som er orienteret således, at strømningen, der udgår fra tromlen, er rettet vinklen γ skråt i forhold til rotationsretningen, henholdsvis rotationsplanet (U).Full cover screw centrifuge according to any of the preceding claims, characterized in that the drain gutter (25) comprises lateral guide walls (31a, 31b) which are oriented so that the flow exiting the drum is directed at the angle γ obliquely in relation to the direction of rotation, respectively the plane of rotation (U).

7. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at afløbsrendens (25) tværsnit er polygonalt eller afrundet.Full cover screw centrifuge according to any one of the preceding claims, characterized in that the cross-section of the drain gutter (25) is polygonal or rounded.

8. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at afløbsrenden (25) omfatter en bundvæg (35), som strækker sig retlinjet i tangential retning (U).Full cover screw centrifuge according to any one of the preceding claims, characterized in that the drainage gutter (25) comprises a bottom wall (35) which extends rectangular in the tangential direction (U).

9. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at overløbspladen (19) på sin bort fra tromledækslet vendende side ikke omfatter noget forlængende rendeelement (29), men blot materialeudsparingen (27), hvis sidevægge (31a, 31b) ikke er orienteret aksialt, men derimod skråt eller krumt i forhold til rotationsretningen (U), henholdsvis rotationsplanet med henblik på således at omstyre den udtrædende strømning noget eller helt i rotationsretningen, henholdsvis rotationsplanet, således at overløbspladerne har en rillet form.Full cover screw centrifuge according to any one of the preceding claims, characterized in that the overflow plate (19) on its side facing away from the drum cover does not comprise any extending gutter element (29), but merely the material recess (27), whose side walls (31a) 31b) is not oriented axially, but is inclined or curved relative to the direction of rotation (U), respectively, of the plane of rotation so as to divert the outgoing flow somewhat or completely in the direction of rotation, respectively, of the plane of rotation, so that the overflow plates have a grooved shape.

10. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at væskeudstrømningen fra afløbsrenden (25) er rettet en vinkel γ skråt i forhold til rotationsplanet.Full-cap screw centrifuge according to any one of the preceding claims, characterized in that the liquid outflow from the drain channel (25) is directed at an angle γ oblique with respect to the plane of rotation.

11. Fuldkappe-skruecentrifuge ifølge krav 10, kendetegnet ved, at γ > 0° og γ < 90°.Full-cap screw centrifuge according to claim 10, characterized in that γ> 0 ° and γ <90 °.

12. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at afløbsrendens (25) bundvæg (35, 35’) i hele sin længdeudstrækning eller afsnitsvist har afrundet form og navnlig strækker sig koncentrisk i forhold til rotationscentret.Full-face screw centrifuge according to any one of the preceding claims, characterized in that the bottom wall (35, 35 ') of the drain gutter (25) has its entire length or sectional length and in particular is concentric in relation to the center of rotation.

13. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav eller ifølge den indledende del af krav 1, kendetegnet ved, at tromledækslet (17) omfatter en eller flere gennemgangsåbninger (15), som hver for sig, i forhold til tromlens (1) længdeakse (D) med henblik på omstyring af udstrømmende væske mod rotationsretningen i periferiretning, henholdsvis periferiplan, er skråtstillet en vinkel δ, som i hvert fald afsnitsvist eller med fordel helt, er større end 0° og mindre end 90°, og for hvilken navnlig følgende gælder: δ >20° og δ <60°.Full cover screw centrifuge according to any one of the preceding claims or according to the preamble of claim 1, characterized in that the drum cover (17) comprises one or more through-openings (15) separately from the drum ( 1) longitudinal axis (D) for the direction of flowing out of fluid towards the direction of rotation in the circumferential direction or circumferential plane, respectively, is inclined at an angle δ which is at least sectionally or advantageously whole, is greater than 0 ° and less than 90 °, and for in particular: δ> 20 ° and δ <60 °.

14. Fuldkappe-skruecentrifuge ifølge krav 13, kendetegnet ved, at hver af de skråtstillede gennemgangsåbninger (15) delvist er dækket af en dertil svarende overløbsplade (19).Full-face screw centrifuge according to claim 13, characterized in that each of the inclined passage openings (15) is partially covered by a corresponding overflow plate (19).

15. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav, kendetegnet ved, at der i den ene eller et antal gennemgangsåbninger (15) er indsat en respektiv indsats (41), hvis indre kontur i forhold til tromlens rotationsakse (D) er skråtstillet en vinkel δ.Full cover screw centrifuge according to any one of the preceding claims, characterized in that a respective insert (41) has a respective insert (41) whose inner contour with respect to the axis of rotation of the drum (D) is inclined at an angle δ.

16. Fuldkappe-skruecentrifuge ifølge et hvilket som helst af de foregående krav 13 til 15, kendetegnet ved, at vinklen δ er lig med vinklen β.Full-cap screw centrifuge according to any of the preceding claims 13 to 15, characterized in that the angle δ is equal to the angle β.