Particulate matter: Interfacial properties, fouling, and its mitigation

Enhancement of Polyacrylate Antiscalant Activity during Gypsum Deposit Formation with the Pretreatment of Aqueous Solutions with Spruce Wood Shavings

“…The studies of the effect of spruce wood shavings on gypsum deposition excluded their presence in the scale forming medium. This is the major difference with previous wood fiber experiments reported in [2,[13][14][15]. The shavings (0.05; 0.10 and 0.5% mass) were added to separate CaCl 2 and Na 2 SO 4 aqueous solutions (0.2 mol•dm −3 ) and to deionized water.…”

“…Unfortunately, the lack of important experimental details in [14,15], such as the sorption of calcium ions and particulate matter, does not allow the mechanism of action to be clarified. At the same time, the proposed interpretation of the data (isolation of the heat transfer surface from the deposit and additional turbulence near the tube walls) [2,11] does not seem convincing. Therefore, the main objective of the present study is to test the antiscaling activity of wood fiber, excluding "fiber-heat transfer surface" interactions, e.g., in supersaturated bulk gypsum solutions with an emphasis on the role of natural particulate matter.…”

“…Such deposits cause serious industrial problems, including reduced thermal efficiency of heat exchangers, increased pressure drop in pipework, flow oscillations and flow blockage. The estimated cost of fouling in some industrialized countries is approximately 0.25% of their Gross National Product (GNP) [2]. Mitigation of scale deposition on heat exchanger surfaces could be achieved by using chemical additives [1], heat exchanger surface modification, modification of heat exchanger operating parameters [2], and other non-chemical methods, such as the application of permanent magnets and electric fields, the introduction of natural fiber into the fouling liquids, etc.…”

“…As a result, scale inhibitors extend the cleaning intervals of industrial equipment. Meanwhile, the use of the most common antiscalants (phosphonates, polyacrylates) raises environmental concerns about the discharge of antiscalant-containing sediments [2]. This problem is partly addressed by biodegradable antiscalants such as polyaspartates or polyepoxysuccinates [7].…”

“…Therefore, the main objective of the present study is to test the antiscaling activity of wood fiber, excluding "fiber-heat transfer surface" interactions, e.g., in supersaturated bulk gypsum solutions with an emphasis on the role of natural particulate matter. Gypsum scale formation in artificially prepared supersaturated aqueous solutions was chosen as the model process following the previous publications on wood pulp fiber activity studies [2,14,15]. These experiments were carried out in comparison with a conventional polyacrylate antiscalant (PAA-F1) [16].…”