Flotation machine for a fiber suspension and method of using same

• US 6,394,279 B1
• Filed: 06/16/2000
• Issued: 05/28/2002
• Est. Priority Date: 06/16/2000
• Status: Expired due to Fees

• Current Assignee: Voith Sulzer Paper Technology North America, Inc.
• Original Assignee: Voith Sulzer Paper Technology North America, Inc.
• Inventors: Cao, Bangji, Witek, Werner, Doelle, Klaus, Heise, Oliver U.
• Primary Examiner(s): Lithgow, Thomas M.
• Application Number:
  US09/595,214
• Time in Patent Office: 711 Days
• Field of Search: 209/168,169,170 210/221.2,221.1 162/4
• US Class Current: 209/168
• CPC Class Codes: B01D 17/00 Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion devices for separating or removing fatty or oily substances or similar floating material from water, waste water, or sewage C02F1/40; cleaning or keeping clear the surface of open water from oil or like materials E02B15/04; arrangements for separating lubricants from refrigerants F25B43/02
• CPC Class Codes: B01D 17/0205 by gas bubbles or moving solids
• CPC Class Codes: B01D 17/0214 with removal of one of the phases
• CPC Class Codes: B03D 1/1462 Discharge mechanisms for the froth
• CPC Class Codes: B03D 1/245 Injecting gas through perforated or porous area

Abstract

A flotation machine is provided which includes at least one flotation cell having an inner chamber. The fiber suspension is transported into the inner chamber, and a gas is injected into the fiber suspension within the inner chamber at a temperature below 20° C. to cause the wax to clump within the fiber suspension. The clumped wax is removed from the fiber suspension.

Claims

1. A flotation machine for removing a contaminant from a fiber suspension, comprising:

a flotation cell having an inner chamber and a generally cylindrical top;

at least one gas injector for injecting a gas into said fiber suspension within said inner chamber at a temperature below 25°

C. to cause the wax to clump within said fiber suspension;

a vertical column generally concentrically positioned within said inner chamber; and

a wax removal device including an elongate element positioned at and configured to move along a top of said inner chamber to remove contaminants from the fiber suspension, said elongate element comprising a roll, said roll having one end pivotally coupled to a top of said column and another end which is carried by and movable along said cylindrical top.

2. The flotation machine of claim 1, said roll including an end coupled with a motor for pivoting said roll relative to said cylindrical top.

3. The flotation machine of claim 1, including a plurality of doctor blades positioned in association with said roll for removing contaminants from said roll and a trough positioned in association with said doctor blades for transporting contaminants away from said roll.

4. The flotation machine of claim 1, said cylindrical top defining an overflow weir and further including an accept trough surrounding said overflow weir.

5. The flotation machine of claim 1, wherein said at least one gas injector comprises a plurality of pancake-type gas injectors.