摘要:
Apparatus and method for grinding levelling of paper, cardboard or a similar continuous web manufactured from vegetative based fibrous raw-material, said apparatus comprising a plurality of grinding means such as rolls or belts preferably arranged on both sides of the web, said means being deviated from the moving direction of the web or the web being deviated from these by means of squeeze rolls and which rolls are characterised by being trioelectrically charged with a similar electrical charge as the ground surface. The web tension can be regulated by moving the grinding means or the web from its direction of movement and the dust generated at the grinding is removed by a vacuum system.
摘要:
A method for coating paper, wherein a coating composition containing coating particles is applied to the surface of a paper web containing lignocellulosic fibers to produce a coated paper web having coating particles bound to the paper web, and the coated web is dried. According to the method the surface area of the interface between the paper web and the coating particles is increased in order to enhance hydrogen bonding between the coating particles and the fibers of the web. The surface area can be increased by using a coating composition comprising fine fibrous material or by abrading the surface of the paper or paperboard web or both. The invention will improve the smoothness of the surface without addition of foreign polymer binding agents to the web.
摘要:
The present invention concerns a method for treating the surface of a fibrous web by mechanical grinding. According to the invention, the grinding is performed at substantially dry state by removing only the higher parts of the paper surface without substantially increasing the density of the web. By reducing the roughness of the surface by a maximum of 90%, the strength properties of the web remain essentially unchanged or they are even improved. Thus, when the roughness of the surface is reduced by about 40 to 60%, the tear strength increases with more that 5% in comparison to an untreated web. Papers and boards treated by the present method can be used for printing, packaging and wrapping.
摘要:
The present invention concerns a process for coating a web by applying a coating layer comprising pigment particles to the surface of the web. According to the invention, the coating layer is contacted at a preselected stage with a smooth surface, the coating layer is at least partially dried while being contacted with said surface to provide a smooth outer surface of the layer with densely packed particles, and the coating layer is separated from the smooth surface. The smooth surface of the web provided by the invention is ideal for printing or for secondary coating with polymers. Paper and board products according to the invention are easily reclaimed and can be treated in a normal pulper, because they do not contain any metal foils or polymer films.
摘要:
The invention concerns a method and an apparatus for cleaning freight containers and for treating and circulating the cleansing liquids. According to the invention, an aqueous soda-containing solution is used as cleansing liquid, volatile organic substances, if any, are separated from the cleansing liquid in a separation unit (4) and in a distillation unit (5) and the liquid obtained in then treated with lime and carbon-containing fly ash in a mixing unit (8). The impurities of the cleansing liquid are sorbed to the activated carbon and precipitate onto the calcium carbonate. The slurry is filtered and the solid material retained in the filter (9) is further fed to a combustion unit (7). Flue gases formed in the combustion unit (7) are treated with the filtrate, whereby sodium hydroxide in the filtrate is transformed into carbonate form, and may be used as new cleansing liquid in combination with makeup chemicals. The volatile organic compounds are used as fuel in the combustion unit. The invention provides an integrated process, in which waste products may be used for treating cleansing liquids.
摘要:
A method for the manufacture of a mold out of mold material from a previous blank by machining each blank into a desired shape by means of a machine tool controlled by a computer utilizing a dimensioning data set. Each blank is manufactured by feeding an organic polymer material whose melting point is preferably lower than 150.degree. C. in liquid form into a box-shaped container which is open at the top and which corresponds to the dimensions of the desired mold. Waste polymer material from the blank upon machining is recovered and heated to a temperature higher than its melting point, whereupon it is fed onto an existing mold no longer needed, so as to provide a new blank for a new mold.
摘要:
A method of producing cement or concrete, comprising the step of adding fly ash to the cement or concrete at the production stage, the fly ash containing lime and reaction products from the reaction occurring between lime and sulphur oxides in connection with the desulphuration of flue gases. To avoid the disadvantageous effects of calcium sulphite and entringite reactions and to increase the used amount of fly ash containing desulphuration waste, the calcium sulphite is oxidized by hydrogen peroxide either before the production of cement or concrete or during the production.
摘要:
A steam generator assembly, particularly for use in connection with the mechanical preparation of pulp, for generating pure steam required in a subsequent process, such as drying of proper in a paper machine, by utilizing the condensation heat of contaminated steam coming from a preceding process, such as a grinding process, includes a steam converter and electrical boiler arranged in a common housing to form a unified structure. The steam converter utilizes the condensation heat of the contaminated steam to generate pure steam from water supplied to the converter. The electric boiler is connected in parallel to the steam converter and includes electrodes adapted to generate steam when moistened by water supplied to the boiler from a separate water container in the housing. Selective control of the supply of water to the electric boiler and the extent to which the electrodes are moistened regulates the amount of pure steam generated by the electric boiler. The pure steam generated by the steam converter and electric boiler is discharged from the common housing through a steam outlet.
摘要:
The invention concerns equipment and a method for enhancing the combustion event and heat transfer in a heating boiler. According to the invention, the space above the major combustion zone in the combustion space of the heating boiler is equipped with sound sources, which are used to generate an acoustic field to enhance the combustion event and to achieve more complete combustion.
摘要:
A process for the recovery of lead from battery scraps by mixing the lead raps at elevated temperature with an aqueous solution of an alkali metal chloride and hydrochloric acid in order to dissolve, in the form of lead chloride, the lead compounds present in the lead scraps, separating an aqueous solution of this lead chloride from insoluble hard lead, which is recovered, crystallizing lead chloride from the cooling aqueous solution, which is separated from the lead chloride crystals, and finally subjecting the obtained lead chloride to electrolysis for the recovery of metallic lead.