# US 4,396,502 A · Screening apparatus for a papermaking machine

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,396,502 A
- Document ID: US4396502A
- Status: Granted
- Kind: A
- Application number: 06/359,318
- Filed: 1982-03-18
- Granted: 1983-08-02
- Earliest claimed: 1982-03-18
- Assignees: Beloit Corporation
- Inventors: Edgar J. Justus
- Web page: https://patentgrep.com/patent/US4396502A

## CPC

- D21D 5/026: {with rotating cleaning foils}
- B01D 29/118: {open-ended}
- B01D 29/72: involving vibrations
- B07B 1/20: Stationary drums with moving interior agitators
- D21D: TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B07B: SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL (wet separating processes, sorting by processes using fluent material in the same way as liquid B03; combinations of dry separating apparatus with wet separating apparatus B03B; using liquids B03B, B03D; sorting by magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high voltage electric fields B03C; centrifuges or vortex apparatus for carrying out physical processes B04; hand sorting, postal sorting, sorting by switching or other devices actuated in response to detection or measurement of some feature of articles or samples of material B07C)

## Abstract

A screen apparatus for processing stock flowing into a papermaking headbox which includes a cylindrical housing, a tubular screen mounted longitudinally within the housing, and inlet means for introducing a stock suspension into the housing for flow through the screen. Outlet means are provided for receiving the suspension passing through the tubular screen for delivery to the headbox. The improvement of the present invention provides a helical slot in the housing which discharges stock passing through the screen into the outlet means. Foil means mounted for rotation coaxially with the cylinder are provided which create a pressure pulsation to cause a dispersal of the fibers and aid in the screening operation.

## Claims

### Claim 1

A screen apparatus for processing stock flowing to a papermaking headbox comprising:
a cylindrical housing,
a tubular screen mounted longitudinally within said housing,
inlet means for introducing a stock suspension into said housing for flow through said screen,
outlet means receiving the suspension passing through said tubular screen for delivery to said headbox,
said housing having a helical slot formed therein which discharges stock passing through said screen into said outlet means, and
foil means mounted for rotation coaxially with the axis of said cylinder.

### Claim 2 (depends on 1)

A screen apparatus according to claim 1 in which:
said slot extends for at least 75% of the length of the foil means.

### Claim 3 (depends on 2)

A screen apparatus according to claim 2 in which:
said foil means includes a rotatable shaft and foils supported radially from said shaft, said foils being spaced approximately 45.degree. apart.

### Claim 4 (depends on 1)

A screen apparatus according to claim 1 in which:
said foil means extends the full width of said tubular screen.

### Claim 5 (depends on 1)

A screen apparatus according to claim 1 in which:
said outlet means is positioned centrally of said screen.

### Claim 6 (depends on 1)

A screen apparatus according to claim 1 in which:
said outlet means has a circular discharge opening of substantially greater diameter than the width of said slot.

### Claim 7 (depends on 1)

A screen apparatus according to claim 1 in which:
the inner wall of said housing and the outer wall of said tubular screen are separated by an annular chamber.

### Claim 8 (depends on 1)

A screen apparatus according to claim 1 in which:
said outlet means is secured to said housing along spaced tangential lines, the angle included between said tangential lines being substantially greater than the angle included between two adjacent foil means.