# US 4,395,331 A · Apparatus for pressing liquid out of material containing liquid

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- Number: US 4,395,331 A
- Document ID: US4395331A
- Status: Granted
- Kind: A
- Application number: 06/352,866
- Filed: 1982-02-26
- Granted: 1983-07-26
- Earliest claimed: 1979-07-09
- Assignees: AB Saffle Gjuteri and Mekaniska Verkstad
- Inventors: Harald Andersson
- Web page: https://patentgrep.com/patent/US4395331A

## CPC

- B30B 9/24: using an endless pressing band
- B30B: PRESSES IN GENERAL (producing ultra-high pressure or ultra-high pressure and high temperature to effect modifications of a substance, e.g. for making artificial diamonds B01J3/00 ){(compressing means for refuse receptacles B65F1/1405)}

## Abstract

An apparatus for pressing liquid out of suspensions containing liquid, comprising a screw feeder (5) adapted to feed the suspensions towards a dewatering zone (2) in which there are disposed two converging endless filter members (20, 21) adapted to be driven round a pair of back and front breaking rollers (18a, 18b). The pressing angle (.alpha.) between the filter members can be varied as can the speed of the filter members in relation to the material which is fed forwards in order to achieve an optimum flow resistance for each suspension. In certain cases, this can be very high. A worm wheel (13) is provided to prevent material from retreating in the screw thread (11). According to one form of embodiment, two or more dewatering zones are disposed in series one after the other, thus further increasing the possibilities for achieving optimum dewatering conditions.

## Claims

### Claim 1

Apparatus for pressing liquid out of liquid-containing material, said apparatus comprising
(a) dewatering means for dewatering said material, said dewatering means including at least one pair of converging, endless, vertically disposed filter members each including
(i) a back and a front braking roller each roller having a vertical axis,
(ii) a perforated support base,
(iii) a filter supported on said support base,
(iv) drive means for driving said filter at a variable speed around said braking rollers, and
(v) adjustment means for rendering at least one of said filter members variably adjustable to vary the pressing angle between that filter member and the other filter member of the pair,
(b) a horizontally disposed screw feeder means for feeding said material in an axial, horizontal direction towards said dewatering means, and
(c) toothed worm wheel means for preventing material from retreating into the thread of said screw feeder means as a result of high flow resistance in the dewatering means by maintaining at least one tooth of said toothed worm wheel means in sealing engagement with said screw feeder means in the thread thereof.

### Claim 2 (depends on 1)

Apparatus of claim 1, wherein said drive means drive the filter at a speed which is lower than the speed of the material passing thereinbetween.

### Claim 3 (depends on 1, 2)

Apparatus as claimed in claim 1 or 2, wherein at least one of said filter members is variably adjustable by displacement of the front braking roller thereof along a circular line, the center of which coincides with the center of the back braking roller.

### Claim 4 (depends on 3)

Apparatus as claimed in claim 3, wherein the thread of the feeder screw has a rounded bottom, and the teeth of the worm wheel have a corresponding circular cylindrical shape.

### Claim 5 (depends on 1, 2)

Apparatus as claimed in either of claims 1 or 2, wherein at least two pairs of converging filter members are disposed in series in successive dewatering zones.

### Claim 6 (depends on 5)

Apparatus as claimed in claim 5, wherein the pressing angles of different pairs of converging filter members are different.

### Claim 7 (depends on 6)

Apparatus as claimed in claim 6, wherein the pressing angle of the downstream dewatering zone is greater than of the upstream dewatering zone.

### Claim 8 (depends on 7)

Apparatus as claimed in claim 7, wherein the filter cloths of the downstream dewatering zone have a greater mesh size than of the upstream dewatering zone.

### Claim 9 (depends on 8)

Apparatus as claimed in claim 8, wherein said drive means drive the filter in the downstream dewatering zone at a lower speed than the filter in the upstream dewatering zone.

### Claim 10 (depends on 9)

Apparatus of claim 9, wherein the apparatus includes two dewatering zones.

### Claim 11 (depends on 9)

Apparatus as claimed in claim 9, wherein the series-coupled filter members are alike.

### Claim 12 (depends on 9)

Apparatus as claimed in claim 9, wherein the pressing angle in the upstream dewatering zone is fixed and the pressing angle in the downstream dewatering zone is variable.