(19)
(11) EP 0 358 837 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Mention of the grant of the patent:
16.03.1994 Bulletin 1994/11

(21) Application number: 88830372.4

(22) Date of filing: 14.09.1988
(51) International Patent Classification (IPC)5B30B 9/16

(54)

Dehydrating screw press with two or more helical elements with intermeshing profiles

Entwässerungsschneckenpresse mit zwei oder mehr schraubenförmigen Elementen mit ineinandergreifenden Profilen

Presse de déshydratation à vis à deux ou plusieurs éléments hélicoidaux à profils s'emboîtant


(84) Designated Contracting States:
AT BE CH DE ES FR GB GR IT LI LU NL SE

(43) Date of publication of application:
21.03.1990 Bulletin 1990/12

(73) Proprietor: FRATELLI BABBINI & C. sas
I-47012 Civitella di Romagna (Forli) (IT)

(72) Inventor:
  • Babbini, Lionello
    I-47012 Civitella di Romagna (Forli) (IT)

(74) Representative: Modiano, Guido, Dr.-Ing. et al
Modiano & Associati S.r.l. Via Meravigli, 16
20123 Milano
20123 Milano (IT)


(56) References cited: : 
DE-C- 883 338
GB-A- 904 328
US-A- 2 567 219
GB-A- 677 794
GB-A- 1 140 237
   
       
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The invention refers to a deshydrating screw press with two or more helical elements, which avoids partial interference zones of the spirals on the product to treat. By using the above mentioned elements side by side, a combined effect of complete conical interference is obtained, in the interspace between their shafts, with a push of the two intersecting spirals, with movement in opposition, which compels the axial advancement of the product.

    [0002] The screw presses are used to deshydrate fibrous materials containing liquid; they are particularly used in the sugar beat treatment, in fodder deshydratation, to extract oils and produce meals for fodders from food stuff recovers such as fish and other. The said presses use two or more helical elements which let the product advance from an end, pressing it inside a filtering cage from which the liquid gets out steadily, while the anhydrous residue is discharged from the other end. This causes a bicylindrical interference space of the spiral filtering cage, which gives rise to non- interference zones, as well as other zones with limited interference of the spirals. This intervention difformity and even of non-intervention of the spiral does not grant a uniformity of pressure of the product and causes losses of delivery. In particularly, when the helical elements are used side by side, zones of limited and even of no interference of the spirals occur, where difficulties can be noted in letting the product advance. Consequently, this one tends to stagnate and in particular, owing to the lateral over-stressing caused by the spirals in these zones, heaping may occur with relevant heavy problems. Moreover the difform advancement of the product causes void spaces which crush and damage the anhydrous residue. Therefore, one can affirm that the speed allowed by the installation cannot be completely made most of, because it must be steadily in conformity with the product to treat and production must steadily be checked to enable timely intervention. In fact, GB-A-677 794 discloses a deshydrating screw press with two or more helical elements with constant profile as defined in the pre-characterising part of claim 1.

    [0003] These inconveniences are obviated by a deshydrating screw press with two or more helical elements with constant profile, working in a filtering cage according to their inteference space, as defined in claim 1, which ensures uniformity in the pressing action of the helical element spiral that is steadily operating with space interference to wall limit. In the interspace between the shafts of the helical elements fitted side by side, the system allows the combined effect of complete interference with push of the intersecting parts of the in opposition turning spirals which compels the axial forward move of the product. In connection, since there are no zones without or with limited interference, the system enables to adjust the delivery to the speed of the propellers. In particular, the smaller space existing in the central intermediate part between the two helical elements, carried out according to the invention, in comparison with the one existing in the already mentioned union with truncated-cone interference, avoids heap-of product; on the contrary, since the two intersecting spirals operate with complete interference up to the wall limit of the two shafts, the gradual axial move of the product is ensured.

    [0004] Substantially, the product to deshydrate in advancing movement is pressed by the rotating motion of two or more screw elements with conical shaft 1 and also conical spiral 2 - total and regular - to operate in a correspondence space to wall limit of the filtering cage 3. If the helical elements with regular total conical interference are used side by side, since the lifting upwards of the spiral 2 is in them in accordance with a like section reduction 4 of its shaft 1, each spiral is allowed to work with profile continuity up to wall limit of the shaft of the other helical element, thus avoiding zones of either no or limited interference on the treated product in the intermediate space between the shafts. Moreover, the movement in opposition of the two or more pressing elements causes a combined effect of complete interference given by the two reciprocally intersecting spirals which compels the axial advancing motion of the product. The filtering cage used for the press with two or more helical elements consists of two components 5 and 6 connected on slanting converging lines 7 and 8 fitted on interference limit of the two or more intersected spirals.

    [0005] An execution version of a deshydrating press, with two helical helements fitted side by side, is illustrated in the schematic drawings of table 1. With reference to this table, fig. 1 is the vertical longitudinal section of the press with side view of a helical element to point out the conical interference spiral which operates up to wall limit of the filtering cage. Fig. 2 is a partial view of horizontal longitudinal section of the press, with view from above of the two flanked helical elements to show the intermediate zone between the two shafts where the interference of the two spirals can be noted, each one of which is working up to wall limit of the other one's shaft. Fig 3 is a view of the press transversal section to show the interference fields of the two spirals.

    [0006] For the press operation, motor 9 is started which, by means of transmission 10 with pulleys 11 and 12, transmits the movements, through reducer 13 on shafts 14, to the helical elements with conical shafts 1 and conical spirals 2. The biconical filtering cage is kept, by the modular grupping U-bolts 15 and 16, in the frame 17 on base 18 and is contained in carter 19 complete with inspection lids 20.

    [0007] In the executions, the use of helical elements is foreseen with constant profile shafts and spirals. The components may fitted in different connections and replaced with other technically equivalent ones.


    Claims

    1. Dehydrating screw press, comprising a pair of rotatable helical elements each of which comprises a conical shaft (1) and conical spiral (2), said pair of rotatable helical elements being fitted side by side such that each conical spiral operates with profile continuity up to the wall limit of the respective conical shaft of the opposite helical element, the press further comprising a filtering cage (3) arranged about said pair of helical elements, characterized in that said filtering cage (3) comprises two components (5 and 6) connected on converging lines (7 and 8) at the interference limit of the two intersected spirals and arranged such that said spirals also operate with profile continuity up to the wall limit of said filtering cage.
     
    2. Deshydrating screw press, as per claim 1, characterized by the fact that the filtering cage used for a press with two or more helical elements, consists of two of more components (5 and 6) connected on converging slanting lines (7 and 8) at interference limit of the two intersected spirals.
     
    3. Deshydrating screw press, as per claim 1, characterized by the fact that the pressing of the product to dehydrate during advancing is performed by the rotating movement of either one or more screw elements with conical shaft (1) and conical spiral (2) with total constant conical interference in order to operate in space of correspondence at wall limit of biconical filtering cage (3).
     


    Ansprüche

    1. Entwässerungsschneckenpresse mit einem Paar von rotierbaren, schraubenförmigen Elementen, von denen jedes einen konischen (kegelförmigen) Schaft (1) und eins konische Spirale (2) aufweist und wobei das Paar der drehbaren, schraubenförmigen Elemente in der Weise nebeneinander angeordnet ist, daß jede der konischen Spiralen mit einer Profilkontinuität zur Wand arbeitet, die von dem entsprechenden konischen Schaft des gegenüberliegenden schraubenförmigen Elementes gebildet ist, und wobei die Presse darüber hinaus ein um das Paar der schraubenförmigen Elemente angeordnetes Filtergehäuse (3) aufweist,
    dadurch gekennzeichnet,
    daß das Filtergehäuse zwei Komponenten (5 und 6) aufweist, die an einer konvergierenden Linie (7 und 8) an der Eingriffsgrenze der beiden sich schneidenden Spiralen verbunden sind und derart angeordnet sind, daß die Spiralen in gleicher Weise mit einer Profilstetigkeit bis zu den Begrenzungswänden des Filtergehäuses arbeiten.
     
    2. Entwässerungsschneckenpresse nach Anspruch 1,
    dadurch gekennzeichnet,
    daß das Filtergehäuse, welches bei einer Presse mit zwei oder mehr schraubenförmigen Elementen eingesetzt wird, aus zwei oder mehr Komponenten (5 und 6) besteht, die an konvergierenden, schrägen Linien (7 und 8) an der Eingriffsgrenze der zwei sich schneidenden Spiralen verbunden sind.
     
    3. Entwässerungsschneckenpresse nach Anspruch 1,
    dadurch gekennzeichnet,
    daß das Verpressen des zu entwässernden Produktes während der Vorwärtsbewegung durch die Rotationsbewegung entweder einer oder mehrerer Schraubenelemente bewirkt wird mit einem konischen Schaft (1) und einer konischen Spirale (2) im vollständigen konstanten konischen Eingriff, um im entsprechenden Abstand mit der Begrenzungswand des bikonischen Filtergehäuses (3) zu arbeiten.
     


    Revendications

    1. Presse de déshydratation à vis, comprenant une paire d'éléments tournants en hélice comprenant chacun un arbre conique (1) et une spirale conique (2), ladite paire d'éléments tournants en hélice étant montée côte-à-côte de telle façon que chaque spirale conique agisse selon une continuité de profil jusqu'à la limite de paroi de l'arbre conique respectif de l'élément en hélice opposé, presse comprenant, de plus, une cage de filtration (3) placée autour de ladite paire d'éléments en hélice,
    presse caractérisée en ce que ladite cage de filtration (3) comprend deux composants (5 et 6) montés sur des lignes convergentes (7 et 8) à la limite d'interférence des deux spirales se coupant et disposés de telle façon que lesdites spirales agissent, de même, avec une continuité de profil jusqu'à la limite de paroi de ladite cage de filtration.
     
    2. Presse de déshydratation à vis selon la revendication 1, caractérisée par le fait que la cage de filtration utilisée pour une presse à deux ou plusieurs éléments en hélice est constituée de deux ou plusieurs composants (5 et 6) montés sur des lignes convergentes en pente (7 et 8) sur la limite d'interférence des deux spirales se coupant.
     
    3. Presse de déshydratation à vis selon la revendication 1, caractérisée par le fait que le pressage du produit pour une déshydratation lors de l'avance est effectué par le déplacement en rotation soit d'un, soit de plusieurs éléments en hélice avec l'arbre conique (1) et la spirale conique (2) selon une interférence conique constante totale de façon à agir dans l'espace de correspondance sur la limite de paroi de la cage de filtration conique (3).
     




    Drawing