Showing papers on "Fouling published in 1975"
TL;DR: In this article, the effect of feed velocity and type of membrane on fouling was investigated in Tokyo industrial water supply in tubular reverse osmosis modules, and the results were analyzed by the deposit accumulation model.
49 citations
Patent•
20 Nov 1975TL;DR: Inorganic phosphorus-containing acids and salts thereof in small amounts function as antifoulant additives in crude oil systems employed as feedstocks in petroleum refining which are subjected to elevated temperatures of from about 100° to 1500° F and which are prone to produce fouling material that deposits and accumulates upon the surfaces of petroleum processing equipment, such as heat transfer equipment and the like.
Abstract: Inorganic phosphorus-containing acids and salts thereof in small amounts function as antifoulant additives in crude oil systems employed as feedstocks in petroleum refining which are subjected to elevated temperatures of from about 100° to 1500° F. and which are prone to produce fouling material that deposits and accumulates upon the surfaces of petroleum processing equipment, such as heat transfer equipment and the like. Such additives not only inhibit and suppress fouling but also reduce fouling in previously fouled refining systems.
41 citations
Patent•
23 Oct 1975TL;DR: Phosphate and phosphite mono-and di-esters in small amounts function as antifoulant additives in crude oil systems employed as feedstocks in petroleum refining which are subjected to elevated temperatures of from about 100° to 1500° F and which are prone to produce material that deposits and accumulates upon the surfaces of petroleum processing equipment as discussed by the authors.
Abstract: Phosphate and phosphite mono- and di-esters in small amounts function as antifoulant additives in crude oil systems employed as feedstocks in petroleum refining which are subjected to elevated temperatures of from about 100° to 1500° F. and which are prone to produce material that deposits and accumulates upon the surfaces of petroleum processing equipment, such as heat transfer equipment and the like. Such additives not only inhibit and suppress fouling but also reduce fouling in previously fouled refining systems.
40 citations
Patent•
20 Nov 1975TL;DR: Thio-phosphate and -phosphite mono-and di-esters in small amounts function as antifoulant additives in crude oil systems employed as feedstocks in petroleum refining which are prone to produce material that deposits and accumulates upon the surfaces of petroleum processing equipment, such as heat transfer equipment and the like as discussed by the authors.
Abstract: Thio-phosphate and -phosphite mono- and di-esters in small amounts function as antifoulant additives in crude oil systems employed as feedstocks in petroleum refining which are subjected to elevated temperatures of from about 100° to 1500° F and which are prone to produce material that deposits and accumulates upon the surfaces of petroleum processing equipment, such as heat transfer equipment and the like. Such additives not only inhibit and suppress fouling but also reduce fouling in previously fouled refining systems.
37 citations
Patent•
20 Nov 1975TL;DR: Phosphate and phosphite mono-and di-esters and thioesters in small amounts function as antifoulant additives in overhead vacuum distilled gas oils employed as feedstocks in hydrodesulfurizing wherein such feedstocks are prone under such processing to produce material that deposits and accumulates upon the surfaces of catalysts and also equipment, such as heat transfer surfaces and the like as discussed by the authors.
Abstract: Phosphate and phosphite mono- and di-esters and thioesters in small amounts function as antifoulant additives in overhead vacuum distilled gas oils employed as feedstocks in hydrodesulfurizing wherein such feedstocks are subjected to elevated temperatures of from about 200° to 700° F and which are prone under such processing to produce material that deposits and accumulates upon the surfaces of hydrodesulfurization catalysts and also equipment, such as heat transfer surfaces and the like. Such additives not only inhibit and suppress fouling but also reduce fouling in previously fouled such systems.
27 citations
TL;DR: In this paper, the effects of chlorine on in situ net primary production in the discharge waters of a power plant at Crystal River, Florida, were studied and the average decrease was 13%.
Abstract: Power plants chlorinate their cooling waters to prevent biological fouling of condenser tube walls. We studied the effects of chlorine on in situ net primary production in the discharge waters of a power plant at Crystal River, Florida. Primary production values decreased an average of 57% due to plant passage and chlorination. In the absence of chlorine, the average decrease was 13%.
24 citations
Patent•
09 Sep 1975
TL;DR: The hull of a marine vessel is protected from fouling by marine growths by a foil of anti-fouling metal such as copper or a copper alloy adhesively bonded throughout its area to the hull below the water line as discussed by the authors.
Abstract: The hull of a marine vessel is protected from fouling by marine growths by a foil of anti-fouling metal such as copper or a copper alloy adhesively bonded throughout its area to the hull below the water line. The foil is conveniently applied to the hull by pressure sensitive or heat sensitive adhesive.
23 citations
Patent•
15 Sep 1975TL;DR: In this article, an olefin is polymerized in a hydrocarbon diluent in a turbulent reaction zone to produce particles of polymer which are substantially insoluble in the dilusent.
Abstract: An olefin is polymerized in a hydrocarbon diluent in a turbulent reaction zone to produce particles of polymer which are substantially insoluble in the diluent. Fouling of the reactor by adherence of polymer particles to the walls of the reactor is reduced by adding to the reaction medium a composition which comprises a mixture of an aluminum or chromium salt of an alkyl salicylic acid and an alkali metal alkyl sulfosuccinate.
19 citations
TL;DR: In this paper, a study of the effects of fouling on catalyst effectiveness and activity has been made, where a Langmuir-Hinshelwood model was used for the main reaction and the fouling reaction was assumed to be first order.
18 citations
Patent•
11 Jun 1975
TL;DR: Toxicant compositions containing the combination of tri-n-butyltin fluoride with zinc oxide and specified substituted triazines effectively inhibit the development of marine organisms, including barnacles and algae, that are responsible for fouling as mentioned in this paper.
Abstract: Toxicant compositions containing the combination of tri-n-butyltin fluoride with zinc oxide and specified substituted triazines effectively inhibit the development of marine organisms, including barnacles and algae, that are responsible for fouling. These compositions are particularly useful as the active component in antifouling coatings.
Patent•
10 Jan 1975
TL;DR: In this article, the surface of an article to be used in or under water and in constant contact with the water is composed of an anti-fouling composition which comprises a polymer and an organo tin compound of the formula: ##STR1## wherein R1 is n-dodecyl and R2 and R3 are methyl.
Abstract: In an article to be used in or under water and in constant contact with the water, at least the surface of the article is composed of an anti-fouling composition which comprises a polymer and an organo tin compound of the formula: ##STR1## wherein R1 is n-dodecyl and R2 and R3 are methyl. X is defined in the specification.
TL;DR: In this paper, a base membrane containing chloromethylstyrene units was treated with oxidizing reagents to determine whether the introduction of carboxylic acid groups onto the membrane surface might make the anion exchange membrane resistant to organic Fouling by anionic organic substances.
TL;DR: In this paper, an anion exchange membrane was modified by sulfonating the surface of the base membrane, composed of styrene-divinylbenzene copolymer and polyvinylchloride, before its chloromethylation and subsequent quarternization.
Patent•
23 Sep 1975
TL;DR: In this paper, an improvement in heat transfer and a reduction in fouling by liquid flowing inside of heat exchanger tubes is achieved by the apparatus and method of the present invention wherein the heat exchange operator includes internally ridged or corrugated metal tubes rather than conventional plain tubes.
Abstract: An improvement in heat transfer and a reduction in fouling by liquid flowing inside of heat exchanger tubes is achieved by the apparatus and method of the present invention wherein the heat exchanger includes internally ridged or corrugated metal tubes rather than conventional plain tubes. Despite the formation of a normal appearing fouling layer on the downstream portion of a ridge, the ridged tubes remain relatively clear on the upstream portion of the ridge. Periodically, as the downstream portions of the tubing ridge surfaces build up a fouling coating, the flow direction of the tube side fluid is reversed to remove at least a substantial portion of the previously deposited coating.
Patent•
04 Aug 1975
TL;DR: In this article, a method for preventing fouling in the slurry polymerization of olefins in a solvent in the presence of a catalyst was proposed, which comprises causing a small amount of a nitrogen-containing salt of phytic acid or a mixture of it with an alkali metal salt of an organic acid to be present as an anti-fouling agent in the polymerization system.
Abstract: A method for preventing fouling in the slurry polymerization of olefins in a solvent in the presence of a catalyst, which comprises causing a small amount of a nitrogen-containing salt of phytic acid or a mixture of it with an alkali metal salt of an organic acid to be present as an anti-fouling agent in the polymerization system.
TL;DR: In this paper, the problem of finding the isothermal optimal control was formulated by a distributed maximum principle and a computational algorithm using a quasi-steady state assumption was presented for the dehydrogenation of isopentane over chromia-alumina catalyst.
01 Dec 1975
TL;DR: In this article, an integrated concept of hull cleaning and fouling control is presented to result in the conservation of fuel and improved ship performance through the development and fleet-wide implementation of cost-effective underwater hull-cleaning methodology to remove and control fouling on Navy ships.
Abstract: : Operating costs and performance efficiency of Navy ships have become matters of increasing concern because of the fourfold increase in cost and the unpredictable availability of foreign and domestic supplies of petroleum fuel. Methods whereby the Navy can conserve fuel are urgently needed. A systematic program for underwater removal and control of fouling is one method which has considerable potential merit for attaining the objective of conserving fuel and improving ship performance. This report reviews the characteristics of fouling and describes underwater hull inspection and cleaning methods. It delineates the interactions among fuel consumption, fouling, and the compatibility of underwater cleaning methods with the antifouling paint coating on the hull. It also presents an integrated concept of hull cleaning and fouling control. A program plan is described which, when completed, is presented to result in the conservation of fuel and improved ship performance through the development and Fleet-wide implementation of cost-effective underwater hull-cleaning methodology to remove and control fouling on Navy ships. Conservative estimates place this fuel saving at 15% of the total quantity consumed by the Fleet. With respect to effective control of fouling, this should assure attainment of the current Navy objective of making ships available for 5 years between successive drydockings. With respect to effective control of fouling, this should assure attainment of effective control of fouling, this should assure attainment of the current Navy objective of making ships available for 5 years between successive drydockings.
Patent•
27 Jun 1975
TL;DR: In this article, a highly dispersed, unconfined acid spray with substantially anhydrous ammonia was used to increase the polymeric P2 O5 content at least 10 percent.
Abstract: Phosphoric acids having H2 0/P2 O5 mole ratios of about 4.5 or less are converted to aqueous solutions of ammonium polyphosphates of which at least about 40 percent of the P2 O5 is present as acyclic polyphosphates. The reaction is conducted at 500° to about 750° F. sufficient to increase the polymeric P2 O5 content at least 10 percent by reacting a highly dispersed, unconfined acid spray with substantially anhydrous ammonia. High conversions to polymeric species are obtained while minimizing both reactor fouling when using impure wet-process acids, and corrosion occurring with either wet-process or "white" acids.
Patent•
28 Jan 1975TL;DR: In this article, a continuous process is envisaged where the decomposition occurs in a series of stirred reactors, and the solvent in the last reactor is depleted of alkylaluminum compound.
Abstract: In the production of aluminum by thermally decomposing an alkylaluminum compound with the aid of suitable apparatus, a problem arises with the fouling of such apparatus by the adherence of aluminum particles. Such fouling is reduced by conducting the decomposition within a neutral liquid solvent which is non-reactive with the alkylaluminum compound and the aluminum produced therefrom and which is at a high temperature well above the temperature at which the compound normally decomposes in the pure state. The neutral liquid solvent is placed in a container and contacted with a heated solid heat transfer member. Transfer of the heat from the member is established to raise the temperature of the neutral liquid solvent to a temperature at least above the decomposition temperature of the alkylaluminum compound to be subsequently added thereto. Transfer of the heat is then terminated to permit the heat transfer member to cool. The alkylaluminum compound is added to the solvent to effect its decomposition with reduced adherence of the resulting aluminum to the heat transfer member. Preferably, the solvent is agitated while the alkylaluminum compound is added. To further minimize this fouling a continuous process is envisaged where the decomposition occurs in a series of stirred reactors. The aluminum alkyl is fed to the first reactor of the series and the solvent in the last reactor is depleted of alkylaluminum compound. This depleted solvent is passed through a heat exchanger and then back to the first reactor. This depleted solvent would not cause fouling of the heat exchanger.