14results about "Slime-control agents addition" patented technology

A method for controlling paper making includes monitoring (302) a surface level of a fibrous suspension in a storage, and identifying (303) that the surface level has decreased so that at least one emptying criterion is met and thereafter identifying that the surface level has increased so that at least one refilling criterion is met, and responsively to the identifying that the surface level has increased so that the at least one refilling criterion is met, starting to dose a biocide agent into the fibrous suspension entering the storage. A corresponding apparatus and computer program are disclosed.

A method for controlling papermaking, comprising: monitoring the liquid level of a fibrous suspension in a reservoir (302); identifying that the liquid level has dropped so as to meet at least one empty criterion (303), and then identifying that the liquid level has risen so as to meet at least one replenishment criterion; and starting to administer a biocide to the fibrous suspension flowing into the reservoir in response to identifying that the liquid level has risen so as to meet at least one replenishment criterion. A corresponding device and computer program are also disclosed.

The invention relates to a method for manufacturing a fibrous web, such as web of paper, board, tissue or the like. The method comprises forming an aqueous fibre suspension comprising cellulosic fibres from one or more raw material flows, and applying at least one chemical and / or physical control measure to the aqueous fibre suspension or at least one of its raw material flows for control of microbial activity in the aqueous fibre suspension or the raw material flow before an inlet of an intermediate residence entity, such as storage tower or broke tower, which has a delay time of at least one hour, preferably at least two hours. In this manner a starting ORP value for the aqueous fibre suspension is obtained. The aqueous fibre suspension in the intermediate residence entity at least the minimum delay time, and a final ORP value is measured for the aqueous fibre suspension after an outlet of the said intermediate residence entity but before the formation of the fibrous web. An ORP difference value between the starting ORP and final ORP values is calculated, and if the ORP difference value exceeds a pre-determined threshold value, then adjusting the applied chemical and / or physical control measure(s) until the ORP difference value falls below the pre-determined threshold value. Finally, the aqueous fibre suspension is formed into a fibrous web and dried.

A method for controlling paper making includes monitoring (302) a surface level of a fibrous suspension in a storage, and identifying (303) that the surface level has decreased so that at least one emptying criterion is met and thereafter identifying that the surface level has increased so that at least one refilling criterion is met, and responsively to the identifying that the surface level has increased so that the at least one refilling criterion is met, starting to dose a biocide agent into the fibrous suspension entering the storage. A corresponding apparatus and computer program are disclosed.

Methods to preserve starch present in pulp are disclosed and also methods to control calcium precipitation and / or scaling in digesters or BOD systems. The methods can be performed as part of a papermaking process. Process water containing pulp can be treated with a chloramine. Process water containing pulp with native starch can receive a double treatment with at least one biocide, such as chloramine, and at least one oxidant, such as sodium hypochlorite. The treatment can be performed in any suitable manner. The treatment can be performed at one or more stages or locations in a papermaking system. A target residual chloramine value or range can be achieved by the treatment. Packaging sheets / boards and other paper products manufactured using the methods provided exhibit superior strength and other desirable characteristics.

The invention relates to a method for manufacturing a fibrous web, such as web of paper, board, tissue or the like. The method comprises forming an aqueous fibre suspension comprising cellulosic fibres from one or more raw material flows, and applying at least one chemical and / or physical control measure to the aqueous fibre suspension or at least one of its raw material flows for control of microbial activity in the aqueous fibre suspension or the raw material flow before an inlet of an intermediate residence entity, such as storage tower or broke tower, which has a delay time of at least one hour, preferably at least two hours. In this manner a starting ORP value for the aqueous fibre suspension is obtained. The aqueous fibre suspension in the intermediate residence entity at least the minimum delay time, and a final ORP value is measured for the aqueous fibre suspension after an outlet of the said intermediate residence entity but before the formation of the fibrous web. An ORP difference value between the starting ORP and final ORP values is calculated, and if the ORP difference value exceeds a pre-determined threshold value, then adjusting the applied chemical and / or physical control measure(s) until the ORP difference value falls below the pre-determined threshold value. Finally, the aqueous fibre suspension is formed into a fibrous web and dried.

The invention relates to a method for manufacturing a fibrous web, such as web of paper, board, tissue or the like. The method comprises forming an aqueous fibre suspension comprising cellulosic fibres from one or more raw material flows, and applying at least one chemical and / or physical control measure to the aqueous fibre suspension or at least one of its raw material flows for control of microbial activity in the aqueous fibre suspension or the raw material flow before an inlet of an intermediate residence entity, such as storage tower or broke tower, which has a delay time of at least one hour, preferably at least two hours. In this manner a starting ORP value for the aqueous fibre suspension is obtained. The aqueous fibre suspension in the intermediate residence entity at least the minimum delay time, and a final ORP value is measured for the aqueous fibre suspension after an outlet of the said intermediate residence entity but before the formation of the fibrous web. An ORP difference value between the starting ORP and final ORP values is calculated, and if the ORP difference value exceeds a pre-determined threshold value, then adjusting the applied chemical and / or physical control measure(s) until the ORP difference value falls below the pre-determined threshold value. Finally, the aqueous fibre suspension is formed into a fibrous web and dried.

A method of controlling volatile fatty acid (VFA) content in a pulp, paper, and / or board making processes is disclosed. The method may be used to provide process improvements in the form of reduced microbial contamination and odor, reduced starch degradation, optimized retention, and improved runability. The method includes treating a process flow comprising a cellulosic material comprising a starch with an enzymatic VFA control agent. The enzymatic VFA control agent is non-biocidal, may further comprise a surfactant or dispersant, and is utilized in an amount sufficient to inhibit microbiological production of one or more VFA. The method optionally includes treating the process flow with a biocidal agent in combination with the enzymatic VFA control agent. A composition for carrying out the method is also disclosed.

Methods to preserve starch present in pulp are disclosed and also methods to control calcium precipitation and / or scaling in digesters or BOD systems. The methods can be performed as part of a papermaking process. Process water containing pulp can be treated with a chloramine. Process water containing pulp with native starch can receive a double treatment with at least one biocide, such as chloramine, and at least one oxidant, such as sodium hypochlorite. The treatment can be performed in any suitable manner. The treatment can be performed at one or more stages or locations in a papermaking system. A target residual chloramine value or range can be achieved by the treatment. Packaging sheets / boards and other paper products manufactured using the methods provided exhibit superior strength and other desirable characteristics.

A method for controlling papermaking, comprising: monitoring the liquid level of a fibrous suspension in a reservoir (302); identifying that the liquid level has dropped so as to meet at least one empty criterion (303), and then identifying that the liquid level has risen so as to meet at least one replenishment criterion; and starting to administer a biocide to the fibrous suspension flowing into the reservoir in response to identifying that the liquid level has risen so as to meet at least one replenishment criterion. A corresponding device and computer program are also disclosed.

A method of controlling volatile fatty acid (VFA) content in a pulp, paper, and / or board making processes is disclosed. The method may be used to provide process improvements in the form of reduced microbial contamination and odor, reduced starch degradation, optimized retention, and improved runability. The method includes treating a process flow comprising a cellulosic material comprising a starch with a VFA control agent. The VFA control agent is non-biocidal, comprises a surfactant or dispersant, a chelator or sequestrant, or a combination thereof, is capable of inhibiting amylase activity in the process flow, and is utilized in an amount sufficient to inhibit microbiological production of one or more VFA. The method optionally includes treating the process flow with a biocidal agent in combination with the VFA control agent.

A water treatment procedure using nanobubbles and biocides in the manufacture of wood pulp, paper, and cardboard that can effectively control the microbial population with higher efficiency than those based solely on biocides, minimize the consumption of water and biocides, apply natural elements, and reduce environmental impacts at low cost. The procedure realizes the combined use of gas nanobubbles in an aqueous medium and a conventional biocide, and consists of the following steps for the treatment of supplied and obtained fresh water. 1. Passing water from a river, reservoir, or well (1) through a nanobubble generator (2) into which an oxidizing gas (3) consisting of oxygen-containing air, pure oxygen, or high-purity ozone is injected; 2. Incorporating a biocide (4) into the mixture with the nanobubbles; and 3. Passing the water through a manufacturing process (5).

Provided herein is a method for treating industrial process water to reduce or prevent proliferation of contaminating microorganisms, such as contaminating bacteria, in apparatus using the industrial process water; which method comprises administering to the water an amount of a phosphorus-scavenging microorganism so as to reduce the level of bioavailable phosphorus in the water. Also provided herein is use of a phosphorus-scavenging microorganism for the reduction or prevention of proliferation of contaminating microorganisms, such as contaminating bacteria, in apparatus using industrial process water by reducing the level of bioavailable phosphorus in the water.