Kvaerner Pulping Ab

Valmet Ab

Gotaverken Energy Ab

Gotaverken Energy Systems Ab

Valmet Power Ab

Lars Gunnar Olausson

Olle Wennberg

Jan Bergman

Sven-Erik Jansson

Anders Henrik Wernqvist

Ola Herstad

Martin Apel

Krister Pettersson

Martin Collander

Anders Åkesjö

Tommy Eriksson

Agneta Larsson

Gustav Carlsson

Hans Sj&ouml;berg

Michael Thiede

Christer Isaksson

Bengt Nyman

Lars Eric Pettersson

Mattias Gourdon

Lennart Lindau

Olof Tryggve Wennberg

Anders ÅKesjÖ

The invention relates to a heat transfer tube () for falling film evaporation having a heating medium surface () to be heated by a heating medium, a falling film surface () to have spent liquor passing over it, and being made from an iron based high alloy stainless steel material with an alloy content above 16.00% for Chromium and above 1% for Nickel. The falling film surface of the heat transfer tube is equipped with one or several protrusions/indentations forming a multitude of stamped bumps (SB) on the envelope surface of a heat transfer tube such that the distance between adjacent stamped bumps (SB) along a line on the envelope surface parallel to the longitudinal axis of the heat transfer tube is within the range of 3 to 250 mm, said stamped bumps (SB) having a height (hp) in the range 0.3 to 5.0 mm, a width (wp) in the range 1.0-20 mm, and an inclination angle (a) versus a plane orthogonal to a longitudinal axis (CC) of the heat transfer tube in a range of 0-70 degrees so that each stamped bump (SB) is inclined and extends along at least a portion of the heat transfer tube or extend within a plane orthogonal to the longitudinal axis of the heat transfer tube. The invention also relates to a method for manufacturing said heat transfer tube.

Heat transfer tube and method for manufacturing a heat transfer tube

The invention relates to a heat transfer tube () for falling film evaporation having a heating medium surface () to be heated by a heating medium, a falling film surface () to have spent liquor passing over it, and being made from an iron based high alloy stainless steel material with an alloy content above 16.00% for Chromium and above 1% for Nickel. The falling film surface of the heat transfer tube is equipped with at least one weld ridge (WR; WR, WR), said weld ridge having a height (h; h) in the range 0.3 to 5.0 mm, a width (w; w) in the range 0.5-15 mm, and an inclination angle (&#x3b1;; &#x3b1;, &#x3b1;) versus a plane orthogonal to a longitudinal axis (CC) of the heat transfer tube in a range of 0-70 degrees so that each weld ridge is inclined and extends helically along at least a portion of the heat transfer tube or extend within a plane orthogonal to the longitudinal axis of the heat transfer tube and forms well ridge portions on the falling film surface such that the distance along the longitudinal axis of the heat transfer tube between adjacent weld ridge portions is within the range of 0 to 250 mm. The invention also relates to a method for manufacturing said heat transfer tube.

The method and equipment are for the evaporation of hot black liquor obtained from a digestion process during the production of cellulose pulp. The black liquor is led to a multistage evaporation line with at least five evaporation stages. The black liquor that is to undergo evaporation in the evaporation line is cooled in at least one heat exchange process in a heat exchanger (HE) against the partially evaporated black liquor that has undergone evaporation in at least one stage (I). The black liquor that is to undergo evaporation is cooled and the partially evaporated black liquor is heated by at least 5-10&#xb0; C. The risk for the formation of foam and the separation of methanol are reduced. The greater part of the evaporation takes place at low temperature and at the lowest level of dry matter content in the liquor, which also suppresses encrustation in the stage.

Method and equipment for the evaporation of black liquor that is obtained from a digestion process during the production of cellulose pulp

The strainer arrangement is adapted for straining a liquid from a mixing arrangement, such as a mixing tank, containing black liquor including solid particles of ash. The strainer arrangement comprises a strainer pipe with axial gaps defined therein for permitting a radial inflow of liquid into the strainer pipe. An axially movable shaft is disposed inside the strainer pipe and has cleaning pins attached thereto that extend into the gaps.

Strainer arrangement for straining liquid from a mixing arrangement

A process for evaporating spent liquor or other waste liquids from cellulose cooking, The evaporation is performed in a multiplicity of evaporators which are coupled in series and in which the evaporation is driven using the liquor steam. The condensates from the steam are divided, in one of more effects, into at least two fractions with respect to purity. The parer fraction from one effect is conveyed, at a high level, into a subsequent effect in the direction of movement of the liquor, while the dirtier fraction is conveyed, at a high level or at the very top, into a preceding effect in the direction of movement of the liquor.

Process for purifying condensate while evaporating waste liquors

An evaporation apparatus for evaporation of, for example, spent liquor from pulp cooking. The apparatus has a vertical cylinder that has evaporation surfaces disposed therein. An outlet opening is defined in a widened part of the cylinder to receive driven-off steam. A skirt is disposed in the cylinder and surrounds the evaporated liquid and driven-off steam and has a diameter that is smaller than a diameter of the widened part. The skirt has an open bottom and a skirt opening is defined in a portion of the skirt that is facing away from the outlet opening.

Evaporation apparatus for evaporation of liquids

Process for the final evaporation of black liquor

Recovery boiler

Recovery boiler and method of reducing NO.sub.x emissions

A combustion plant includes a circulating fluid bed, which is maintained by the supply of fuel, inert material and oxygen-containing fluidizing gas to a vertical furnace shaft. This is, at its upper end provided with an outlet for combustion gases and bed materials, which is separated from gas in a separating means, and by way of a lock is returned to the furnace shaft. The separating means is of a mechanical type, and located vertically above a further vertical shaft communicating with the lock. The further shaft encloses distribution means for the particles and a heat exchanger for cooling the particles falling from the gas stream, before they are re-introduced into the furnace shaft by way of the lock.

Combustion plant including a circulation fluid bed

Growing community of inventors

Angered, Sweden

Lars Gunnar Olausson