Kurita Water Industries Ltd. and Nippon Synthetic Chemical Industry Co. | Date: 2017-01-18
Provided is a method for producing paper and a pitch removal agent that can remove pitch efficiently. A pitch removal agent having an average polymerization degree of 300 to 2500, a saponification index of 70 to 88 mol % and satisfying, when the absorbance at a wavelength of 490 nm is designated as y (Abs) and the saponification index as x (mol %), the Numerical Formula (A) below is added to a pulp slurry during production of paper using waste paper in the step of deinking the waste paper by floatation and/or a step earlier:
Kurita Water Industries Ltd. | Date: 2017-01-25
A method for treating a circulating water in a wet paint booth, the method comprising adding a treatment agent comprising an aqueous solution comprising a tannin and an alkali metal hydroxide and/or an alkali metal carbonate to the circulating water in any of passages for the circulating water in the wet paint booth, wherein the passages include for supplying the circulating water from a water tank to a paint booth, for collecting an uncoated paint in the circulating water, and for returning the circulating water to the water tank; to detackify the uncoated paint collected in the circulating water.
Kurita Water Industries Ltd. | Date: 2017-01-04
Provided are a device for controlling chemical injection into a boiler and a chemical injection method, which can control an injection amount such that a chemical concentration is obtained as per a target even in a boiler feed-water facility where a flow rate of feed-water varies to a large extent in a short period. A device for controlling the injection of a chemical into a boiler controlles an amount discharged by a chemical injection pump 37 in proportion to a flow rate measured by a flowmeter 40. An average chemical concentration in a feed-water is calculated from an amount of feed-water per predetermined period obtained by the flowmeter 40 and a reduction in the amount of chemical in a tank 36 per predetermined period obtained by a sensor 39. The chemical injection pump 37 is controlled on the basis of the calculated average chemical concentration and a preset target chemical concentration of the feed-water so that the average chemical concentration is within the target chemical concentration range.
Kurita Water Industries Ltd. | Date: 2017-04-26
A coagulation monitoring device monitoring a treatment state of water to be treated undergoing a coagulation treatment includes a laser light irradiating part irradiating laser light on a measurement region of the water to be treated, the laser light being emitted at at least predetermined time intervals and subjected to an amplitude modulation at a predetermined frequency; a scattered light receiving part receiving scattered light from particles of the water to be treated residing in the measurement region; a signal processing part extracting a measurement value indicative of an intensity of the scattered light, from light-reception signal obtained at the scattered light receiving part; and a measurement value arithmetic part continuously or discontinuously capturing m (m=2 or more) sets of plural measurement values, each set consisting of n (n=2 or more) measurement values, the measurement value arithmetic part extracting a plurality of measurement values in ascending order from a lower value for each set, the measurement value arithmetic part figuring out an average measurement value from a plurality of measurement values with a lowest value removed therefrom. This enables avoidance of influence of flocs generated in water to be treated during coagulation and ensures stable measurement of SS turbidity of water to be treated.
Kurita Water Industries Ltd. | Date: 2017-02-03
A facility management system quickly creates information required for maintenance or the like of a water treatment facility, after water is sampled at the water treatment facility. The facility management system includes a management center including an operation database in which information indicating an operating status of a water treatment facility is stored, a portable water quality analyzer configured to perform water quality analysis on water taken from the water treatment facility, and a communication apparatus configured to acquire an analysis result from the portable water quality analyzer and wirelessly transmit the analysis result. The management center receives the analysis result transmitted from the communication apparatus, creates information indicating the operating status of the water treatment facility, by using the analysis result, and registers the information in the operation database.
Kurita Water Industries Ltd. | Date: 2017-05-31
An adequate control of a pH of circulating water circulating through a wet paint booth enables an efficient coagulation treatment of a paint included in the circulating water. A method for treating circulating water circulating through a wet paint booth and including a paint includes treating the paint included in the circulating water by adding an alkaline solution of a phenolic resin to the circulating water, and adjusting a pH of the circulating water to 6.5 to 8.0. An amount of the alkaline solution of the phenolic resin added to the circulating water is increased when the pH of the circulating water is a predetermined value of 8.0 or less. An acidic aluminum salt is further added to the circulating water. An amount of the acidic aluminum salt added to the circulating water is increased when the pH of the circulating water is a predetermined value of 6.5 or more.
Kurita Water Industries Ltd. | Date: 2016-02-03
Provided are a method and an agent for treating water in a cooling water system equipped with an iron-made facility, both of which can prevent the corrosion of iron and can also prevent the formation of calcium-containing scales effectively. A method for treating water in a cooling water system equipped with an iron-made facility, which comprises adding a combination of tungstic acid and/or a tungstate, and polyacrylic acid and/or a copolymer to the cooling water system, wherein the copolymer is produced by copolymerizing acrylic acid with a monomer having a sulfonic acid group, and the content of acrylic acid in the copolymer is 97% or more.
Kurita Water Industries Ltd. | Date: 2016-05-18
An efficient slime control method in a white water circulation line in a paper making process is provided. The present slime control method in a white water circulation line in a paper making process including the steps of: aerating with an oxygen-containing gas either one or both of a white water circulation line and the water feeding line for feeding water into the white water circulation line; and adding a slime control agent to at least one line of the white water circulation line and the water feeding line aerated with the oxygen-containing gas in the aerating step. Preferably, the step of measuring at least one selected from the group of measurement items consisting of the oxidation reduction potential, the sulfite ion concentration and the amount of dissolved oxygen in the white water circulation line is further included. Based on the measurement result obtained in the measurement step, the aeration rate in the aerating step and/or the amount of the slime control agent added in the adding step of the slime control agent may be regulated.
Kurita Water Industries Ltd. | Date: 2016-08-03
In a cooling water system having been subjected to an antimicrobial treatment using chlorosulfamic acid or a salt thereof, algae growing therein are effectively killed and removed. An antimicrobial and algicidal method for a cooling water system characterized in that in a cooling water system subjected to an antimicrobial treatment using a chlorosulfamic acid and/or a chlorosulfamic acid salt, when algae are generated, an isothiazolone-based compound is further added to the cooling water system. The chlorosulfamic acid and/or a salt thereof are added to the cooling water system in such a manner as to give a residual chlorine concentration of 0.5 mg-Cl_(2)/L or higher.
Kurita Water Industries Ltd. | Date: 2016-12-21
Provided are a method for removing scale and a scale remover that can efficiently remove scale deposited inside a boiler can or the like in an addition amount of chemicals permissible in terms of cost without corroding a boiler, particularly can efficiently remove scale deposited inside a boiler can even in a facility operated with feed water containing high-concentration iron. A method for removing scale deposited in a system of a steam generating facility, wherein polyacrylic acid having a weight-average molecular weight of more than 20,000 and 170,000 or less and/or a salt thereof is added to feed water of the steam generating facility. When the feed water contains iron, polymethacrylic acid having a weight-average molecular weight of more than 1,000 and 100,000 or less and/or a salt thereof is further added in combination.