US-12616923-B2 - Sealing strip for sealing adjacent filter plate assemblies of a filter press, such as a tower press, a filter frame, a filter frame assembly and a filter apparatus

Abstract

A sealing strip for sealing adjacent filter plate assemblies of a horizontal filter press. The disclosure is based on the idea of providing the sealing strip with a stiffener at a base portion of the sealing strip, positioned such that it intersects with a line running through a ridge provided on a distal portion of the sealing strip and extending along a vertical direction, perpendicular to both the length direction and the width direction of the sealing strip, as seen along the cross-sectional profile of the sealing strip. A filter frame, a filter frame assembly and a filter apparatus having such a sealing strip are also provided.

Inventors

• Mirva MUSTAKANGAS
• Ismo JUVONEN
• Janne KAIPAINEN
• Teemu ELORANTA
• Mika ILLI
• Kari VÄNTTINEN

Assignees

• Metso Outotec Finland Oy

Dates

Publication Date

20260505

Application Date

20200417

Claims (20)

1. 1 . A sealing strip for sealing adjacent filter plate assemblies of a horizontal filter press, the sealing strip comprising: an elongate body extending along a length direction, and having first longitudinal end, a second longitudinal end and a cross-sectional profile; a base portion configured to be attached in a corresponding groove of an associated filter frame or filter plate assembly; a distal portion for sealing against an adjacent filter plate assembly, a ridge being provided on the distal portion for increasing a sealing pressure thereat, when the sealing strip is compressed against an adjacent filter plate assembly, and an intermediate portion between the base portion and the distal portion, wherein the intermediate portion has a width, defined along a lateral direction transverse and coplanar to the length direction, less than that of the base portion, wherein the sealing strip further comprises an elongate stiffener running along at least a part of the length of the sealing strip, wherein the stiffener is positioned at the base portion such that it intersects with a line running through the ridge and extending along a vertical direction, perpendicular to both the length direction and the width direction, as seen along the cross-sectional profile, and wherein the stiffener is encapsulated by the body of the sealing strip, wherein the stiffener is longitudinally spaced apart from both of the first longitudinal end and the second longitudinal end of the elongate body.
2. 2 . The sealing strip according to claim 1 , wherein the stiffener is longitudinally spaced apart for a distance of 1 mm-10 mm from each of the first longitudinal end and the second longitudinal end.
3. 3 . The sealing strip according to claim 1 , wherein the stiffener is of a material having a greater rigidity than that of the body of sealing strip.
4. 4 . The sealing strip according to claim 3 , wherein the stiffener has an elastic modulus of at least 100 times greater than that of the body.
5. 5 . The sealing strip according to claim 1 , wherein the stiffener has a cross-sectional maximum width along the lateral direction of between 10%-85% of the cross-sectional maximum total width of the sealing strip along the lateral direction.
6. 6 . The sealing strip according to claim 1 , wherein the stiffener has a cross-sectional maximum height along the vertical direction of between 10%-50% of the cross-sectional maximum total height of the sealing strip along the vertical direction.
7. 7 . The sealing strip according to claim 1 , wherein the sealing strip is asymmetric with respect to a centre line running vertically through a lateral centre of the distal portion, thus defining a chamber side and an outer side.
8. 8 . The sealing strip according to claim 7 , wherein the base portion extends laterally further on the chamber side than on the outer side, with respect the centre line.
9. 9 . The sealing strip according to claim 7 , wherein the intermediate portion extends laterally further on the outer side than on the chamber side, with respect the center line.
10. 10 . The sealing strip according to claim 7 , wherein the base portion exhibits a larger curvature on the chamber side than on the outer side.
11. 11 . The sealing strip according to claim 10 , wherein in the cross-sectional profile of the sealing strip, on the chamber side, the curvature of the base portion extends up to the intermediate portion continuously.
12. 12 . The sealing strip according to claim 7 , wherein, on the outer side, the cross-sectional shape of the base portion exhibits a linear contour extending up to the intermediate portion.
13. 13 . A filter frame assembly for supporting a filter plate of a horizontal filter press, the frame assembly comprising a filter frame defining a boundary forming a laterally closed planar opening, wherein the filter frame comprises, on a planar side thereof, a sealing groove surrounding the planar opening, wherein the sealing groove has a cross-sectional profile comprising: a bottom portion, and a neck portion opening between the bottom portion and the planar side of the filter frame, wherein the neck portion has cross-sectional width less than that of the bottom portion, wherein the filter frame assembly further comprises the sealing strip according to claim 1 , wherein the sealing strip is received in the sealing groove, such that the bottom portion of the filter frame form-fittingly engages the base portion of the sealing strip, thereby securing the sealing strip to the filter frame.
14. 14 . The filter frame assembly according to claim 13 , wherein the sealing strip is asymmetric with respect to a centre line running vertically through a lateral centre of the distal portion, thus defining a chamber side and an outer side.
15. 15 . The filter frame assembly according to claim 14 wherein the base portion exhibits a larger curvature on the chamber side than on the outer side and wherein in the cross-sectional profile of the sealing strip, on the chamber side, the curvature of the base portion extends up to the intermediate portion continuously.
16. 16 . The filter frame assembly according to claim 14 wherein, on the outer side, the cross-sectional shape of the base portion exhibits a linear contour extending up to the intermediate portion.
17. 17 . A horizontal filter press wherein the horizontal filter press comprises: a plurality of filter frame assemblies according to claim 13 , wherein the filter frame assemblies are configured movable towards each other into a closed position in which a filter chamber is formed between adjacent filter frame assemblies, and away from each other to an open position in which adjacent filter frame assemblies are spaced apart from each other; a filter medium arranged between adjacent filter frame assemblies; a translation arrangement for moving the filter frame assemblies towards each other so as to form a filter chamber between adjacent filter frame assemblies, and away from each other so as to open the filter chamber; a feed arrangement for feeding slurry into the filter chamber; a recovering arrangement for recovering filtrate from the filter chamber, and a discharge arrangement for discharging a filter cake formed within the filter chamber.
18. 18 . The sealing strip according to claim 3 , wherein the stiffener has an elastic modulus of at least 500 times greater than that of the body.
19. 19 . The sealing strip according to claim 3 , wherein the stiffener has an elastic modulus of at least 1,000 times greater than that of the body.
20. 20 . The sealing strip according to claim 3 , wherein the stiffener has an elastic modulus of at least 10,000 times greater than that of the body.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the U.S. national stage application of International Application PCT/FI2020/050255, filed Apr. 17, 2020, which international application was published on Oct. 21, 2021, as International Publication WO 2021/209680 A1 in the English language. FIELD OF THE DISCLOSURE The present disclosure relates to filter presses, such as horizontal filter presses, e.g. tower presses, and more particularly to sealing strips used in such filter presses for sealing the interface between adjacent filter frame assemblies, between which a filter chamber is formed. The present disclosure further concerns a filter frame, a filter frame assembly and a horizontal filter press apparatus, such as a tower press. BACKGROUND OF THE DISCLOSURE A sealing strip has conventionally been used for sealing the interface between two adjacent filter frame assemblies, in between which a filter chamber is formed. Such a filter frame assembly may be formed by a frame-and-plate assembly, or a recessed plate incorporating the frame and plate portions. The sealing strip must be able seal the filtration pressure prevailing in the filter chamber against the environmental pressure, in addition to withstand the compression pressure at which the adjacent filter frame assemblies are pressed against each other. Due to the repetitive compression cycles and the often abrasive nature of the slurry being filtered, the sealing strip is a wear part which must be replace periodically. The sealing strip is commonly attached to the filter frame by providing the frame with as groove having a cross-sectional profile that tightly matches that of the sealing strip, so as to secure the two to each other, while the elasticity of the sealing strip allows it to be inserted into the groove during installation. As the sealing strip must surround a relatively large filter chamber, the sealing strip is typically provided as an elongate strip having a first longitudinal end and as second longitudinal end (as opposed a strip formed as a closed loop) for manufacturing and installation reasons. Consequently, the longitudinal ends must adjoin each other firmly, so that a tight seal is formed between the longitudinal ends of the sealing strip. As the sealing strip is made from an elastic material for practical reasons, achieving a sufficient abutting compression between the longitudinal ends of the sealing strip is typically rather cumbersome and time consuming. This is firstly because the sealing strip elastically deforms when the longitudinal ends are presses against each other, and secondly because the remaining sealing strip that is already inserted in the groove of the frame prevents the axial ends from being pushed against each other, and tends to pull the longitudinal ends back. Attempts to overcome this have been made by using an adhesive to secure the position of the sealing strip in the groove, thus fixing the axial ends of the strip pressed against each other. However, this hinders the removal and replacement of the sealing strip, as the groove must be cleaned from remains of the adhesive before a new sealing strip can be installed. Additionally, the adhesive must be allowed to set before the filter frame assembly can be used. Moreover, a sealing strip requires a sufficient height extending out from the groove on the filter frame to allow sufficient compression to achieve a required sealing effect. However, it is not desirable to have an excessive height of the sealing strip extending out of the groove, as this increases the distance which adjacent filter frame assemblies must travel to open and close the filter chamber and to achieve a sufficient sealing pressure at the sealing strip, thereby increasing the cycle time of each filtration cycle. At the same time, the sealing strip requires require a sufficient height extending within the groove so that the sealing strip is securely attached to the filter frame. However, increasing the height of the sealing strip even within the groove also increases the distance which adjacent filter frame assemblies must travel to open and close the filter chamber and to achieve a sufficient sealing pressure at the sealing strip, thereby increasing the cycle time of each filtration cycle. BRIEF DESCRIPTION OF THE DISCLOSURE An object of the present disclosure is to provide a sealing strip for sealing adjacent filter plate assemblies of a horizontal filter press, such as a tower press, which sealing strip provides for shortened cycle times and improved sealing between the longitudinal ends of the sealing strip and the interface between the sealing strip and an associated groove, while simultaneously facilitating installation and replacement. It is a further object of the present disclosure to provide a filter frame, a filter frame assembly and a filter apparatus. The objects of the disclosure are achieved by the sealing strip, filter frame, filter frame assembly and the filter apparatu