Abstract: A batch type digester for wood chips in which a stream of wood chips is delivered into the center of the top of the digester tank, while liquor is being delivered through a pair of pipes at the top of the tank. Simultaneous with the delivery of the wood chips and liquor, a steam vortex is formed in the upper part of the tank by a plurality of steam jets which are directed downwardly and tangentially and form spiral flow paths below the streams of chips and liquor. The wood chips and liquor are dispersed together and the liquor thoroughly wets the chips. The chips produce a substantially even layer as they fall to the bottom of the tank. The steam vortex maintains a negative relative pressure zone which promotes the dispersion of the stream of chips and the liquor.

Abstract: An improved washer for removing impurities or other substances from a porous mat disposed over a vacuum head. As disclosed, in connection with an industrial paper making process, the porous mat is paper pulp and an elongate chamber, disposed axially above the drum, has a slot along its bottom with resilient downwardly extending skirts disposed around the edges of the slot. Water under pressure in the chamber is directed downward, and into the pulp mat. The resilient skirts prevent the wash water from flowing tangentially with respect to the mat so that the flow of water into the mat is essentially perpendicular to the mat. The chemicals within the mat are positively displaced by relatively clean wash water.

Abstract: A system and method for removing colloidal suspensions or particles from a liquid, in particular tall oil soap particles from black liquor of a wood pulping process. Black liquor is moved along a flow path from an upstream to a downstream zone. First and second electrical conductors are respectively located in the upstream and downstream zones and means are provided for applying opposite electrical potentials to these conductors. For removal of anionic colloids, the first conductor is made positive and the second conductor negative. Thus, colloidal particles in the liquid having a relative potential opposite to the potential of the first conductor are attracted towards the first conductor as the liquid flows through the upstream zone, and some of the ions attached to some of these particles are stripped off by the electrical field, leaving these particles with a potential of the opposite polarity from particles not so affected.

Abstract: A batch type digester for wood chips in which a stream of wood chips is delivered into the center of the top of the digester tank, while liquor is being delivered through a pair of pipes at the top of the tank. Simultaneous with the delivery of the wood chips and liquor, a steam vortex is formed in the upper part of the tank by a plurality of steam jets which are directed downwardly and tangentially and form spiral flow paths below the streams of chips and liquor. The wood chips and liquor are dispersed together and the liquor thoroughly wets the chips. The chips produce a substantially even layer as they fall to the bottom of the tank. The steam vortex maintains a negative relative pressure zone which promotes the dispersion of the stream of chips and the liquor.

Abstract: A method and apparatus for separating saponified tall oil or soap from black liquor which has been stored in an open pond. During such storage, the tall oil saponifies into soap, and the soap separates somewhat and a portion of it settles with the lignin to the bottom of the pond. A submerged propeller is operated by an internal combustion engine on a boat and directs a liquid and gas stream into the layer of liquid soap "sludge" so that the soap is whipped and dispersed. The whipping action causes the soap particles to agglomerage so as to form larger soap portions. The propeller also produces small bubbles of air which become attached to the soap portions thus aiding them in floating to the pond surface. The soap forms in a layer and is pushed along the liquid surface into a discharge tank from which it is pumped to a tank truck. The soap is then hauled to a plant where it is processed.

Abstract: A system and method for removing colloidal suspensions or particles from a liquid, in particular tall oil soap particles from black liquor of a wood pulping process. Black liquid is moved along a flow path from an upstream to a downstream zone. First and second electrical conductors are respectively located in the upstream and downstream zones and means are provided for applying opposite electrical potentials to these conductors. For removal of anionic colloids, the first conductor is made positive and the second conductor negative. Thus, colloidal particles in the liquid having a relative potential opposite to the potential of the first conductor are attracted towards the first conductor as the liquid flows through the upstream zone, and some of the ions attached to some of these particles are stripped off by the electrical field, leaving these particles with a potential of the opposite polarity from particles not so affected.

Abstract: A method and apparatus for continuously removing agglomerable particles from a liquid, such as for example tall oil soap particles from the black liquor formed in a wood pulping process, are disclosed wherein a substantially continuous stream of the liquor is supplied to a first container wherein the liquor is whipped in the presence of air to agglomerate soap particles into particles of substantially larger size. The foam is then removed from the first container, near the top of the container, and supplied in a deaerating apparatus which deaerates the foam and produces a mixture of liquid and agglomerated soap particles. This mixture is then supplied to a skimming tank wherein the soap particles float to the top of the tank and are removed while liquid is drained from the bottom of the container.

Abstract: A method of an apparatus for improving the capacity and efficiency of electrostatic precipitators by increasing the average field intensity. The precipitator is supplied with a substantially constant base level DC voltage that is less than the sparking threshold level of the precipitator, and superimposed thereon is a periodic DC voltage waveform of short duration having peak levels that substantially exceed the sparking threshold level. By controlling the characteristics of the periodic DC voltage waveform the average applied voltage is greater than the sparking voltage but the duration of the instantaneously applied voltage is not sufficient to cause sparking in the precipitator.