Pulp industry, process fluids

There are three chapters in this volume, two of which address the microscale. Ploehn and Russel address the Interactions Between Colloidal Particles and Soluble Polymers, which is motivated by advances in statistical mechanics and scaling theories, as well as by the importance of numerous polymeric flocculants, dispersants, surfactants, and thickeners. How do polymers thicken ketchup Adler, Nadim, and Brenner address Rheological Models of Suspensions, a closely related subject through fluid mechanics, statistical physics, and continuum theory. Their work is also inspired by industrial processes such as paint, pulp and paper, and concrete and by natural systems such as blood flow and the transportation of sediment in oceans and rivers. Why did doctors in the Middle Ages induce bleeding in their patients in order to thin their blood ... 

Many industrial processes rely on effective agitation and mixing of fluids. The application of agitators cover the areas of mining, hydrometallurgy, biol-ogy, petroleum, food, pulp and paper, pharmaceutical and chemical process industry. In particular, in these industries we find typical chemical reaction engineering processes like fermentation, waste water treatment, hydrogenation, polymerization, crystallization, flue gas desulfurization, etc [65, 21]. 

Uses Emulsifier for min. oils, animal oils, lubricants, metalworking fluids, cutting oils, cosmetics, agric. codetergent for industrial use defoamer in effluent treatment, pulp/paper processes low foaming additive in detergents, l l hard surf, cleaners, pulp/paper chems. 

Industrial aqueous process fluids, e.g. cooling waters, pulp and papermill process waters and suspensions, secondary oil recovery systems, spinning fluids, metal working fluids. 

Since it is in acidic solutions that Bronopol features the highest stability, weakly acid media are the ideal field of application. This imposes limitations on the applicability of Bronopol as a preservative, especially in alkaline industrial fluids which contain amines able to form N-nitroso compounds, e.g. metal working fluids. To overcome the limited antifungal activity of Bronopol combinations with other actives, e.g. with isothiazolones such as 15.3 and 15.6 are recommended. As a slimicide Bronopol may be used in industrial process water (15-100 mg/ 1), in pulp and paper mills (10-250 mg/1), in oil field operations (50-100mg/1). 

In the food industry it has often been difficult to obtain true viscosity measurements (unithj.j) of complex fluid foods such as coarse fruit suspensions. These are usually non-Newtonian suspensions. Fruit concentrates are dispersions of solid particles (pulp) in aqueous media (serum). Their rheological properties are of interest in practical applications related to processing, storage stability, and sensory properties. Expensive rheometers are often not available in quality control and product development laboratories. However, viscosity is nonetheless an important quality factor of these products. 

Pulp and paper industrial equipment design consists of proper material seleetion in conjunction with the process chemicals and prevention of stagnant fluids in the process equipment. In the absence of corrosion, low-alloy carbon steel would be the material of choice if corrosion were not a problem. However, for many processes, stainless steel and even nickel-base and titanium alloys are required for better performance in corrosive environments. At present, current US paper mills are constructed of about one-third carbon steel and two-thirds stainless steels. There are several grades in the group of stainless steels. The relative cost of the stainless steels is dependent on the concentration of the major alloying elements (Cr, Ni, Mo), the volume produced, and the form in which it is supplied such as tube, pipe, plate, or block. It is useful to note that stainless steels are 10-20% more expensive than low-alloy carbon steels. 

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