Abstract: A method for measuring and controlling a chip level and/or a chip-liquor combination level and/or liquor level height of a liquid-steam phase digester or a hydraulic digester which digester comprises a chip screw for feeding chips into a digesting volume. The method comprises mounting electrode pairs in certain heights and vertically at distances from each other in the digesting volume of the digester, the electrode pairs being formed of electrodes; connecting the electrode pairs to electric circuits; measuring in each electric circuit a current or voltage value during operation of the digester; determining, based on the measurement, type of material layer (for example, steam, chips, combination of chips and liquor, or liquor) located in a certain height, based on the electrical conductivity of the materials in the digesting volume.

Abstract: The invention relates to a method for cleaning water or an aqueous flow electrochemically by flotating impurities contained in water for collecting the impurities from a surface of the water. The method includes conveying the water flow to be cleaned through at least one particle bed which behaves bipolarically under electric voltage, which bed is formed of an anode and a cathode and metal particles arranged between the anode and the cathode; leading a changing direct current to the particle bed to maintain electrochemical reactions on anodic regions and cathodic regions of the particles; and dissolving metal of the particles electrochemically to water to split water to micro bubbled hydrogen gas H2 for the flotation and to hydroxide ions OH— for increasing pH of water. The invention relates also to an apparatus for cleaning water or an aqueous flow electrochemically.

Abstract: The invention relates to a method in the wet end of a web forming process. In the method, at least one electrode pair (102, 103) is placed in the wet end. The electrode pair (102, 103) is supplied with a current/voltage from a power source (100), so that an electric field is set up between the electrode pair (102, 103), causing the material particles in the pulp suspension in the wet end to be electrically charged in a desired manner and to move in a desired manner in the pulp suspension in the wet end. The current/voltage of the power source (100) is controlled by means of a measuring and control unit (101) so as to cause the material particles in the pulp suspension to be electrically charged and to move in a desired manner, thus allowing the retention, formation and orientation of the material particles in the pulp suspension to be substantially improved.

Abstract: The invention relates to a method in the wet end of a web forming process. In the method, at least one electrode pair (102, 103) is placed in the wet end. The electrode pair (102, 103) is supplied with a current/voltage from a power source (100), so that an electric field is set up between the electrode pair (102, 103), causing the material particles in the pulp suspension in the wet end to be electrically charged in a desired manner and to move in a desired manner in the pulp suspension in the wet end. The current/voltage of the power source (100) is controlled by means of a measuring and control unit (101) so as to cause the material particles in the pulp suspension to be electrically charged and to move in a desired manner, thus allowing the retention, formation and orientation of the material particles in the pulp suspension to be substantially improved.

Abstract: The invention relates to a method for measuring the properties of a stack (15) that viscous molten salt forms on the bottom of a soda recovery unit (14) while black liquor is burned therein, and for measuring the corrosion of the materials of construction of the unit (14) during the operation thereof. In the method, at least one sensor means (11) is brought into contact with said stack (15), this sensor means (11) being electrically insulated from the soda recovery unit (14). In the method, at least some electrochemical properties and the temperature of said stack (15) are measured with this sensor means (11). The data measured with this sensor means (11) are fed to a measuring and data acquisition unit (12), and said measuring and data acquisition unit (12) is controlled by a control unit (13).

Abstract: The invention concerns a method for inhibition of growth of organisms on faces of constructions (11) submerged in a liquid. In themethod, an electrically conductive structure (11) to be protected is connected as the cathode of a source (14) of direct current, or an electrically non-conductive structure (111) to be protected is first coated with an electrically conductive material (111a) and connected as the cathode of a source of direct current (14), respectively, and, as the anode (12), an anode is used that has been isolated from the structure (11) to be protected or that is placed separate from said structure, which anode is connected as the anode of the source (14) of direct current.

Abstract: The invention relates to a method for fixing an electrode arrangement to be used in the cathodic protection of concrete structures. In the method, an anode (20) is mounted in a framework (11) and the framework with its anodes is mounted on the concrete structure at a production plant or in the mounting step before the concreting step. The invention also relates to a fixing element (10) of the electrode arrangement to be used in the cathodic protection of concrete structures, which fixing element is comprised of an anode (20) and a framework (11), which framework (11) is provided with means (15) for fixing the element (10) to the concrete structure.

Abstract: An electrode system and method, including a measurement electrode, a reference electrode and a counterelectrode, for measuring hydrogen peroxide concentration in a solution. For the measurement electrode, an electrode made from titanium, zirconium, tantalum or niobium is used.

Abstract: The invention relates to a method for separating plastic particles (P) from a suspension (L), e.g. from a cellulose mass or cellulose pulp suspension, in which the fiber-floc material is broken for loosening the plastic particles (P). In the method, turbulent flows are caused to said suspension (L), by means of which flows the particles (P) to be separated are separated from the remaining mass as the fiber network is decomposing, whereby lighter particles (P) are separated. In the method, the suspension (L) obtained in the previous phase is subjected to such a treatment that a concentration difference is achieved, which prevents the fiber network from reforming and thereby the plastic particles (P) from binding thereto, and a flow (F) is directed to the separation point, where the plastic particles (P) are separated from the suspension (L).

Abstract: Plastic particles are separated from liquid mediums having the same distributed therethrough, in particular cellulose and paper fiber-containing mediums by electrolytic separation. The liquid medium is introduced into a container provided with an anode, a cathode and a reference electrode, with the plastic particles being separated from the liquid medium by controlling the potential of the anode and the cathode so that the potential of the anode is at most 2800 mV S.C.E., preferably +1200 to -300 mV S.C.E., and the potential of the cathode is at least -3500 mV S.C.E., preferably from +120 to -2100 mV S.C.E. The control of the potentials of the electrodes is effected to such ranges that gas production is selectively provided on the electrodes for cleaning thereof.