Low Foam Research Articles

Microstructure-based modeling to characterize low pore density open-cell foams and its experimental validation.

Microlattices with large pore sizes are involved in many multifunctional applications, so it is essential to understand their acoustic properties. However, for these low pore density microlattice foams, the classical homogenization or "equivalent fluid" methods fail abruptly. This paper proposes and discusses a microstructure-based direct fluid model (DFM) that would help to predict the acoustic performance of low pore density periodic open-cell foams with spherical pores. The DFM is simulated directly, including the microscale geometric features inherent in the unit cell. A comparative study is performed for designed three-dimensional (3D) body-centered-cubic (BCC) porous foams having pores per inch (PPI) ranging from 1 to 12 over the frequency range of 500-4100 Hz with equivalent fluid models and experiments. The study shows the extent of deviation in homogenization-based methods from the experiment for PPI < 5. On the other hand, the acoustic performance parameters predicted with the DFM agree well with experiments on 3D-printed samples fabricated by additive manufacturing of varying PPI starting from 1. This study shows that the DFM is a valid method to predict the acoustics of low PPI microlattices. Furthermore, the gradual transition from dissipative to the reactive regime with a decrease in PPI is also brought out.

Comparative study on the foam and air-water interface properties of ethanol-soluble and non-ethanol components in wheat aqueous phase protein

We conducted an investigation into the foam and interface properties of wheat aqueous phase protein (WAP) along with its ethanol-soluble fraction (ES) and non-ethanol-soluble fraction (NES). The results reveal that the ES component exhibits exceptional foamability at both pH 5 and 7, whereas the NES component demonstrates relatively lower foamability but excels in foam stability at pH 5 and 7. The ES component shows a higher initial surface pressure, indicating stronger surface activity and, consequently, superior foamability. In contrast, the NES component exhibits a faster adsorption rate. The surface dilatational modulus of all three proteins increases over time and with varying frequencies, forming an interface layer primarily characterized by elastic behavior. Notably, the NES component displays heightened sensitivity to oscillations, suggesting its enhanced capacity to form a stable adsorption layer at the interface, thereby contributing to foam stability. Within WAP, the combined interactions of the ES and NES components dictate its foam properties, with the ES component primarily influencing foamability and the NES component playing a more significant role in foam stability. This study offers valuable insights into the intricate behavior of wheat proteins at gas-liquid interfaces, thereby enhancing our comprehension of the formation and stability mechanisms of dough aqueous phase foams.

Enhancing strategies for the activity and H2O resistance of MnCo-CMS flexible SCR catalysts and hydrophobic modification by modulating the surface energy

Melamine sponge is a flexible organic rubber-plastic foam characterized by its highly porous three-dimensional mesh structure. By optimizing the carbonization process of the melamine sponge, NH3-SCR catalysts with enhanced flexibility were developed. In this study, MnCo-CMS (Carbonized melamine sponge) catalysts were synthesized using the impregnation method. Response surface methodology (RSM) and central composite design (CCD) were employed to investigate the effects of impregnation time, loading, and calcination temperature on the mass reaction rate and N2 selectivity. The results showed that loading had the most significant influence, followed by calcination temperature and impregnation time. Under the optimal preparation conditions of 32.5 wt% loading, the calcination temperature at 420 °C, and the impregnation time for 342 min, the mass reaction rate could reach 11.02 cm3min-1g−1, and the N2 selectivity could achieve 87.4 %. Experimental validation confirmed that various preparation processes resulted in catalysts with high SCR activity (rate constant k > 9.5 cm3min-1g−1 and N2 selectivity > 80 %). The Mn-Co loading should be within the range of 28–36 wt%, the calcination temperature within the range of 380–420 °C, and the impregnation time should be 150 min or more. Materials with low surface energy could result in excellent hydrophobicity. In this study, it was found that melamine sponges could be modified into low surface energy carbon foams by temperature modulation. The change in surface energy was utilized as a modification approach to enhance the water resistance of the NH3-SCR catalyst. Importantly, the optimized process significantly improved the stability and water resistance of the catalysts.

Characterization of polymer foam evolution in unpressurized melt systems

AbstractThe evolution of foam in unpressurized melt processing techniques, such as rotational molding, is different from high‐pressure processes like injection foam molding, making comparisons difficult. This has driven the need for a dedicated technique for studying these systems. A unique test procedure was developed to capture and characterize foam evolution in test tubes under unpressurized conditions. A validation study found the procedure to be reliable, producing repeatable samples (height average (AVG) 39.69 ± 1.70 mm and density AVG 0.319 ± 0.012 g/cm3) and delivering comparable results to samples produced using the industrial rotational foam molding process. A study examined the effect of polymer particle size on the foam structures produced. Finer (&gt;90 μm &lt;106 μm) polymer powders produced more desirable structures, achieving 38.6% lower foam density and 43.8% taller peak foam height than coarser powders (&gt;425 μm &lt; 500 μm). Cycle times were much shorter (~15 min) in comparison with the industrial rotational molding process (&gt;40 min) and required smaller amounts of materials, making it useful for rapid characterization. Future work is planned to apply the new procedure to investigate the effects of material and processing conditions on the foam structures produced under unpressurized conditions.Highlights Evaluation of existing unpressurized foam characterization methods. Rapid test procedure developed to characterize unpressurized foam evolution. Variability study of foam structures produced using the new procedure. Effect of rotational molding polymer powder and considerations for foaming. Results validated with industrial unpressurized rotationally molded samples.

Pore-scale resolved simulation of quenching, acceleration, and transition to detonation of hydrogen explosions by metal foams

Pore-scale simulations of quenching, acceleration, and transition to detonation of gaseous hydrogen explosions by metal foams were performed. The model solves the three dimensional compressible reactive Navier-Stokes equations with detailed chemistry in a closed square channel with a metal foam placed inside. The structures of the foam were fully resolved using an immersed boundary method. Stoichiometric mixtures of hydrogen-oxygen and hydrogen-air were considered. An explosion in the channel was initiated with a high-pressure and high-temperature spark. The simulation results show that the explosion can be quenched, accelerate, or transition to detonation depending on the foam pores-per-inch (PPI). Hydrogen-air explosions were quenched with foams of ∼39 PPI or higher due to heat losses from the flame, which is consistent with experimental observations. The explosion was not quenched by foams with low PPI. Instead the low PPI foams exacerbated the explosion by causing flame acceleration. Worse, a 78 PPI foam caused a stoichiometric H2 and O2 mixture to transition to detonation. Hydraulic resistance due to products venting away from the flame surface was found to produce strong pressure gradients within the foam. This causes a self-pressurizing effect that grows as the flame propagates further into the foam. The pressure within the foam grows and steepens into a shock. The shock initiated the detonation by a Mach reflection, which is similar to deflagration-to-detonation transition mechanisms in traditional obstacle-laden channels. Statement of SignificanceMetal foam structures are often used as devices to inhibit flames in scenarios where explosion hazards are a concern. Direct numerical simulations were performed to increase understanding of how flames and explosions interact with metal foams. The simulation results show that high pores-per-inch (PPI) foams quench the explosion by removing heat from the flame. Lower PPI foams can have the opposite effect and exacerbate the explosion by promoting flame acceleration or even transition to detonation. Flames self-pressurize as they propagate through low PPI foams due to hydrodynamic friction and gas-dynamic effects from flowing product gases. In extreme cases, the pressure waves near the flame can steepen into a shock and initiate a detonation. These results indicate that improperly selected metal foam flame arresters can exacerbate the explosion.

Development of open-pore polymer and ceramic foams/Guefoams with tunable fluid-dynamic properties: Application in highly efficient water bacteria removal

The usual replication method for preparing open-pore metal foams using NaCl as a template cannot be successfully applied to the fabrication of foams using either water-based ceramic slurries in which NaCl can be dissolved during processing, or liquid polymers that wet NaCl and leave no interconnecting windows between pores. In this work, we propose to modify the replication process by including a second template, paraffin, which is deposited over the NaCl and serves a dual purpose: (i) it acts as a barrier to dissolution of the NaCl with the matrix precursor, and (ii) it creates size-controllable binding collars between the particles that ensure the formation of interconnecting windows in the foam. The usefulness of the process described here is illustrated by the fabrication of two types of materials: low porosity epoxy and cement matrix foams and Guefoams. As proof of concept, epoxy-based Guefoams were developed for the removal of Escherichia coli in water using iodine-impregnated activated carbon particles as the guest phase. The results indicate that the Guefoams outperform conventional bactericidal particle beds in several aspects, including their ease of handling and their tunable fluid-dynamic properties that enable high bacteria annihilation efficiency.

Effect of sintering on processability vis‐a‐vis microcellular foaming of ultrahigh molecular weight polyethylene

AbstractProcessing of ultrahigh molecular weight polyethylene (UHMWPE) involves sintering due to its high melt strength and no flowability above melting temperature. Variations in compression molding pressure during sintering lead to chain rearrangement at the sintered interphase and the boundary, affecting foamability. UHMWPE particles are sintered using compression molding; samples are prepared at two different pressures: UHPE‐HP (80 bar) and UHPE‐LP (40 bar) at 180°C. The sintering phenomenon of UHMWPE particles is observed through an optical microscope, and their effect on foaming was observed. UHPE‐HP foams are systematically studied to obtain the foaming window. Increasing foaming pressure (80–120 bar) made UHPE‐HP foams softer (0.350–0.219 g/cm3) with varying average cell size (26.37–46.1 μm) and foam cell density (3.98 × 107–1.06 × 108 cells/cm3), and compression modulus decreased from 9 to 5.4 MPa. DMA results showed a strong dependence of stiffness on crystallinity, and foamed samples exhibit higher stiffness than their unfoamed counterpart. The storage modulus for foamed samples decreases with increase in the gas content. The UHPE‐LP foam is relatively softer, with a lower foam density (0.233 g/cm3), a higher expansion ratio, bigger average foam cells (35.13 μm), and lower foam cell density (9.33 × 107 cells/cm3). This is due to constrained crystallinity at the interphase and pre‐existing cavities, favoring the foaming.

Preparation and properties of silane cross-linked polyethylene nanocomposite foams: The effect of silane and nanoclay type and content

In this study, silane grafted and moisture cross-linked low density polyethylene nanocomposite foams were prepared by melt mixing and batch foaming process and the effects of silane content, nanoclay content, foaming agent concentration and clay type (clay modified with vinyltriethoxysilane (VTES) and amino-propyltriethoxysilane on foaming efficiency and foam properties were investigated. The morphology and the efficiency of silane modification of modified clay were characterized by series of tests, including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The results of Fourier transform infrared and thermogravimetric analysis showed that the silane modifiers were bonded to the surface of nanoclay through both physical and chemical bonds. According to XRD, these modifiers caused characteristic peak of clay to shift to lower angles, and make an increase in basal spacing. Gel content, density, scanning electron microscopy, compression, creep and rheological tests were used to determine the effect of different parameters on properties of cross-linked polyethylene foams. Results indicated that silane content has the significant effect on stress-strain behavior in compression mode. Compression set and creep deformation were affected by cell size and gel content. Furthermore, the rheological properties including complex viscosity, storage and loss modulus of unformed samples increased with the addition of silane and nanoclay content.

Synthesis and surface properties of branched-chain tertiary fatty alcohol sulfate surfactants

Abstract In this paper, anionic branched-chain tertiary fatty alcohol sulfate surfactants were synthesized from n-hexene and n-octene using selective olefin dimerization, hydration reaction (hydroxylation), and sulfur trioxide sulfation. The direct hydration reaction of the α-olefin dimer 2-butyl-1-octene with water as a model reaction was explored for the synthesis of branched-chain tertiary fatty alcohols. Two branched-chain tertiary fatty alcohol sulfate surfactants, namely C12-SBTAS and C16-SBTAS, with different carbon chain lengths, were synthesized by the sulfur trioxide sulfation method. Their structures were confirmed by various analytical techniques, including HPLC, FT-IR, HR-MS, and 1H NMR. Equilibrium and dynamic surface tension, foaming, wetting, and emulsifying properties were compared with those of Guerbet cetyl alcohol sulfate (C16-SGAS). C12-SBTAS and C16-SBTAS exhibited good surface activity with equilibrium surface tension (γ CMC) values of 27.41 mN m−1 and 26.69 mN m−1, respectively. They also had low foaming and rapid defoaming abilities, as well as good wetting and emulsifying properties, which match the application characteristics of typical branched-chain surfactants.

Vibrational comfort improvement for a passenger car driver seat

Abstract This paper presents an experimental study aimed at providing new insights into passenger vehicle driver seat vibration. The study investigates the effects of various driver seat components on the damping coefficient. By employing a design for six sigma method, an optimized seating solution is proposed to enhance seat comfort levels. The control factors used in this study include seat cushion upholstery, topper foam, cushion foam, pulmaflex, torsion bar and seat structure. Seat position, foam thickness and body mass are considered as potential noise factors. Subjective evaluation of seat comfort is conducted using the SAE J 1441-2016, comparing three different passenger car driver seats. The seats are disassembled from the vehicles and mounted on a six-degree-of-freedom shaker test bench. Vertical vibration data are filtered, and transmissibility curves are experimentally obtained from the seat rail to the seat cushion via a pad. Uncomfortable seat prototypes are then manufactured, and alternative configurations are tested on the shaker. The objective and subjective evaluations of the seat prototypes reveal that lower foam hardness, higher foam density, and flexible upholstery contribute to improved comfort levels. Moreover, the prototype seat with optimum parameters receives a subjective evaluation SAE score of +0.75, indicating an enhancement in comfort.

An improved latent heat thermal energy storage using two layers of metal foams

Latent Heat Thermal Energy Storage (LHTES) systems are essential due to their remarkable ability to compactly store significant thermal energy. Their pivotal role extends to various energy applications, prominently including solar heaters and waste thermal energy recovery initiatives. Metal foams have the ability to improve heat transmission and thermal charging of energy storage units dramatically. However, the metal foam cannot store latent heat energy, so the goal is to improve heat transfer by using minimal foam mass. Here, the LHTES is made of several parallel channel enclosures with a square cross-section of 120 mm in height/width. There is a 21 °C temperature difference between the heated channel walls and PCM fusion temperature. In the current study, the influence of the configuration of two metal foam layers was addressed on melting time in LHTES. The idea is to use heavy foam (porosity 0.90) in places where there is low convection and light foams (porosity 0.975) in places with good convection heat transfer to enhance thermal charging and keep the storage weight low. Therefore, three configurations of splitting into half, an L shape division, and splitting diagonally for foam layers were examined. The influence of metal foam configurations on melting volume fraction, thermal energy storage, isotherms, and streamlines was examined. The geometrical configuration of foam layers could significantly influence the thermal charging time and energy storage profiles. The best layer configuration was a horizontal splitting of the enclosure with a light foam layer (high porosity metal foam) at the top. The well-configured foam layer could complete the charging process in 837 s, 32% faster than the same splitting but placing the light foam layer at the bottom.

Phenylene‐containing polyethylenimine‐like polymers absorb and release CO2 to blow biomass‐based polyurethanes

AbstractCO2 adducts of hydrophobically modified polyethylenimines (PEIs) are promising alternatives to global warming halogen‐containing blowing agents of polyurethanes (PUs), despite the high cost of the raw material PEIs. Herein, an economical synthesis of PEI‐like polymers was explored via condensation between pentaethylenehexamine and terephthalaldehyde, followed by chemical reduction of the as‐formed Schiff base linkages. The resultant p‐phenylene‐containing polyamine polymers (PEIPs) could be grafted with alkyl (Cn) side chains and adducted with CO2 to form a new type of CO2‐releasing blowing agents for PUs designated as yCn‐xPEIP‐CO2s, where x and y represent the backbone molecular weight and the side chain grafting rate, respectively. Among them, the specimen 10%C8−3.6 kPEIP‐CO2 was the most effective in terms of good dispersibility in PU raw materials, low foam density (about 51 kg/m3), and uniform pore morphology. Moreover, the phenylene linkages enhanced the hydrophobicity of the consequent CO2 adducts and weakened the intermolecular hydrogen bonding and ionic attraction, both facilitating the dispersion of the corresponding blowing agents into a castor oil‐derived polyol, Polycin M‐365. The specimen 10%C8−3.6 kPEIP‐CO2 could disperse as suspended fine floccules that finally aggregated into a flocculent, liquid‐like bottom layer, being easily redispersed into the bulk. The unique compatibility with plant oil‐derived polyols and the economic availability would make the PEIP‐based blowing agents suitable for the next generation of sustainable and biomass‐based PU foams.

Fabrication and performance of bidirectional cantilever sensor with conductive Thermoplastic Polyurethane porous foams

Cantilever sensors are widely used in many application areas due to their bidirectional sensing performances. In this paper, we propose a bidirectional cantilever sensor with asymmetric sandwich structure via the simple low-temperature template casting and freeze-drying methods. The high sensitivity TPU porous foams are embedded in the low sensitivity foams, which changes the conductivity and sensitivity of asymmetric sandwich structure in different bending direction. Here, direction of the deformation in the cantilever beam can be detected by the piezoresistive behaviors. The results of the experiments demonstrate the asymmetric sandwich structure cantilever sensor exhibits good flexibility, excellent stability, rapid response speed, and remarkable bidirectional sensing.

Biomechanical Performance of a Novel Implant Design in Simulated Extraction Sites and Sinuslift Procedures

With increasing experience and in an attempt to shorten overall treatment times, implant placement in combination with tooth extractions and sinus lift procedures has become popular. In both cases, primary stability has to be achieved by either engaging apical and oral regions of trabecular bone or by engaging residual host bone beneath the sinus cavity. Extraction sites were formed by pressing a root analog into homogeneous low density polyurethane foam which was used as bone surrogate while a 3 mm thick sheet of medium density foam was used for mimicking a sinus lift situation. Two types (n = 10) of bone level implants with a conventional tapered design and a cervical back taper (NobelActive; control) and a novel design characterized by a shift in core diameter and thread geometry (AlfaGate; test) were placed in these models following conventional osteotomy preparation. Insertion torque was measured using a surgical motor and primary stability was determined by resonance frequency analysis. Statistical analysis was based on Welch two sample t tests with the level of significance set at α = 0.05. In sinuslifting, NobelActive implants required significantly higher insertion torques as compared to AlfaGate (p = 0.000) but did not achieve greater implant stability (p = 0.076). In extraction sites, AlfaGate implants showed both, significantly higher insertion torques (p = 0.004) and significantly greater implant stability (p = 0.000). The novel implant design allowed for greater primary stability when being placed in simulated extraction sockets and sinuslift situations. While in extraction sockets the position of condensing threads in combination with an increase in core diameter is beneficial, the deep cervical threads of the novel implant lead to superior performance in sinuslift situations.

Influence of particle fluorination on the stability of honey foam

Honey foam has applications in the food, cosmetic, and pharmaceutical industries. For example, honey foam can be used in bread or biscuit spread (food industry), as a carrier of topical bioactive ingredients (cosmetic industry), or as a carrier of drugs (pharmaceutical industry). However, the conditions for obtaining a stable honey foam remain unclear. In this study, we investigated the influence of particle fluorination on honey foam volume and foam stability by aerating natural (unadulterated) honey with fluorinated fumed silica (50%–75% SiOH) or fluorinated sericite clay (PF-5–PF-12) particles. Higher foam volume (≤4.3 cm3) and foam stability (up to a year) were observed with the least (75% SiOH) fluorinated fumed silica particles, while lower foam volume and foam stability were observed with the moderately (59% SiOH) and most (50% SiOH) fluorinated fumed silica particles. In contrast, regardless of the degree of fluorination, the fluorinated sericite clay particles yielded little (&amp;lt;1 cm3) and unstable foam that collapsed completely within 4 weeks of preparation. Therefore, with respect to honey foam stabilization, fluorinated fumed silica particles are superior to fluorinated sericite clay particles. These foams can be used for topical formulation of cosmetic and pharmaceutical products, and our findings will guide future stabilization of honey foam for target applications.

Experimental study of the effects of salinity on nanoparticle-surfactant foams for fracture stimulation application

Liquid foams have been increasingly studied and used in hydraulic fracturing application to develop unconventional resources. In recent years, silica nanoparticles (SNP) have been commonly applied to improve foams' thermal stability and performance under reservoir conditions. While liquid foams are highly affected by salt concentration, the influences of salinity on the foams' characteristics have yet to be clearly understood. This paper investigates the effects of salinity on the properties of SNP-surfactant-stabilized foams. The key experiments included the zeta potential and particle size measurements of SNP in surfactant solutions and the foamability, stability, rheology and proppant suspension tests on the studied foams. The results showed that the increase in the NaCl salt concentration reduced the electrostatic repulsion and promoted the aggregation behaviour among the SNP. At higher salinity, the SNP-surfactant-stabilized foams were found to have lower initial volumes, shorter half-lives, reduced apparent viscosity and faster proppant settlement. Furthermore, it was observed that all the studied foams became extremely unstable with very low foamability and had limited proppant suspension capacity when the salinity was increased to 5%. This observation is critical to evaluate the compatibility of fracturing foams when interacting with the formation brine and to improve the process of recycling produced water as a base fluid to generate foams. The outcomes of this study enhance our understanding of the influences of salinity on the properties of liquid foams and contribute to developing a practical guideline for the foam-fracturing application under harsh reservoir conditions.

Application of Nanoparticles to Enhanced Oil Recovery

Due to the disadvantages of traditional EOR methods, such as low sweep efficiency, formation damage and poor environmental protection, nanotechnology has attracted great attention in improving oil recovery due to its cost-effectiveness and environmental protection. Common types of nanoparticles that can play an effective role in enhancing oil recovery include oxides of aluminum, zinc, magnesium, iron, zirconium, nickel, tin and silicon. At home and abroad in this paper, the different types of nanomaterials research progress on the reservoir and production technology are introduced in detail, involving nanoparticles in effect on the viscosity of heavy oil and hydraulic fracturing technology, heat recovery technology, low salinity water injection technology and steam foam flooding technology and changing wettability, to reduce the oil/water interfacial tension and so on the basis of theoretical research and application situation. Scholars at home and abroad have carried out a lot of experiments and numerical simulations on the role of nanoparticles in enhancing oil recovery, as well as the required concentration and action conditions, and elaborated on the mechanism of nanoparticle enhanced oil recovery. In this paper, the latest research progress in this field at home and abroad is reviewed, and the key problems and development direction in the application of nanotechnology are pointed out.

Significantly Improved Foamability and Mechanical Properties of Polypropylene through a Core–Shell Structure via Low Gas Pressure Foam Injection Molding

Lightweight plays an important role in energy conservation and emission reduction. Foam injection molding (FIM) is a promising technology for the mass preparation of structural parts. But it is still a challenge to prepare foam with good cellular structure via low gas pressure foam injection molding (LGP-FIM). Polypropylene (PP) as a kind of universal plastic exhibits good mechanical properties, but its mechanical properties are notably deteriorated after foaming. In this study, ethylene-propylene-diene monomer (EPDM) rubber and high-density polyethylene (HDPE) were added to PP to improve its melt strength and increase the gas diffusion rate. As a result, the cell size of the ternary blend attained was ∼2 μm, and the cell density was increased to 1010 cells/cm3. Meanwhile, the tensile toughness of ternary blend foam increased by 668% compared to PP foam. The notched impact strength of ternary blend foam increased by 178% compared to PP foam. Considering the excellent performance of PP foam and the low cost of LGP-FIM, this work presents a method for fabricating high mechanical performance foams that could be easily industrialized.

Preparation and properties of modified starch-based low viscosity and high consolidation foam dust suppressant

Aiming at the high-concentration dust pollution in open-pit coal mines, a foam dust suppressant with low viscosity and consolidated coal dust is developed. In order to reduce the limited effect of binder viscosity on the foaming ability and wettability of foam, tapioca starch is oxidized with Cu2+/H2O2 System in this study to reduce the molecular weight of the polymer and prepare materials with high consolidation and low viscosity. The dust suppression performance of the sample is measured, and the microscopic adsorption mechanism of the dust suppressant is investigated by molecular dynamics simulation. The results show that the oxidized starch adhesive solution consists of 20 g tapioca starch, 0.88 ml hydrogen peroxide, 2.4 g sodium hydroxide, and 0.48 g copper sulfate, which need to be diluted to 10 times the original volume, and 1 g of surfactant (sodium fatty alcohol polyoxyethylene ether sulfate/alkyl Glycoside=1:4) is added to prepare a new foam dust suppressant. The viscosity is 2.6 mPa·s, the foaming multiple is 6.25, the contact angle is 13.73° at the first second, the hardness reaches 70.75 HA, and a dust suppression rate of 98.17% for PM10. The dust suppressant can effectively suppress coal dust.

Experiment Study on the Effectiveness of Various and Mixed Kinds of Low Expansion Foam of 120# Gasoline Pool Fire Suppression

Storage tank fires can endanger society and the environment by generating intense heat radiation, rapidly spreading blazes, and cataclysmic explosions. Various types of foam and even two or more mixed foams are commonly used in storage tank fire disposal sites. This research aims to experimentally and analytically assess the efficacy of various and mixed forms of foam in putting out 120# gasoline pool fires. A series of foam fire extinguishing and re-ignition tests were conducted using a laboratory fire-extinguishing device that gently released low-expansion foam. In this work, a 2.4 m-diameter steel round tray was utilized to model the full-surface fire of an oilcan in a large oil depot base. The non-dimensional (T* = TExtinguishing/Tboiling point) average temperature of 0.62–0.66 is used in this study to represent the fire extinguishing temperatures of 120# gasoline fuel. The power law is still followed during the spreading phase as the length of the foam spreads further with time. When combined, 6% aqueous film-forming foam solution and alcohol-resistant aqueous film-forming foam solution (AFFF + AFFF/AR) have the highest flow velocity of 0.0189 m s−1. According to the results, synthesis foam solution combined with alcohol-resistant fluoroprotein foam (S + FP/AR) provided the greatest cooling effect, followed by S + S/AR (alcohol-resistant synthetic foam solution), AFFF/AR, S + AFFF, S/AR + AFFF, and finally S/AR + AFFF. According to the results, foam with an expansion ratio of 8.7:1 (FP (fluoroprotein foam solution) + AFFF/AR) has greater re-ignition resistance and burn-back protection. A referable tactic for choosing foam for liquid fire suppression is shown in this paper. The results suggested that FP and AFFF should be used for effective fire suppression in this hydrocarbon fuel fire rescue. Then, we can use synthetic foam and AR foams to provide continuous cooling and prevent the fire from re-igniting through efficient foam coverage.