Abstract: A roll of embossed paper towelling in which the embossing comprises lands and valleys between the lands wherein the lands are in rows extending at an acute angle to the longitudinal direction of the towelling. The acute angle of the rows of lands offsets each land with respect to the lands of the next adjacent turns or layers of the towel in the roll. That causes the layers to be held apart, and the desirable characteristics of the towels are preserved. There is also apparatus and a method for producing the embossed paper towelling. An embossing roll has a continuous spiral row of embossing elements or patterns which produce the embossing on the towelling. The spiral rows are at an angle of the order of five degrees from the longitudinal edges of the towels, i.e., the edges extending in the direction of the embossed sheet.

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 roll of embossed paper towelling in which the embossing comprises lands and valleys between the lands wherein the lands are in rows extending at an acute angle to the longitudinal direction of the towelling. The acute angle of the rows of lands offsets each land with respect to the lands of the next adjacent turns or layers of the towel in the roll. That causes the layers to be held apart, and the desirable characteristics of the towels are preserved. There is also apparatus and a method for producing the embossed paper towelling. An embossing roll has a continuous spiral row of embossing elements or patterns which produce the embossing on the towelling. The spiral rows are at an angle of the order of five degrees from the longitudinal edges of the towels, i.e., the edges extending in the direction of the embossed sheet.

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.