scholarly journals Optimization and Modeling of Slightly Acidic Electrolyzed Water for the Clean-in-Place Process in Milking Systems

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1685
Author(s):  
Yu Liu ◽  
Chaoyuan Wang ◽  
Zhengxiang Shi ◽  
Baoming Li
Keyword(s):  
Stainless Steel ◽  
Energy Efficient ◽  
Treatment Time ◽  
Rubber Gasket ◽  
Electrolyzed Water ◽  
Response Surface Models ◽  
Stainless Steel 304 ◽  
Surface Models ◽  
Efficient Alternative ◽  
Commercial Detergent

To find an environmentally friendly and energy efficient alternative to acidic detergent for a milking system clean-in-place (CIP) process, this study investigated the feasibility of applying slightly acidic electrolyzed water (SAEW) alone to wash the system by cleaning soiled stainless steel (304) pipes, rubber gaskets, and PVC milk hoses, which were used in the milking system. The results showed that SAEW with appropriate parameters could achieve the same or even better hygienic effects compared with commercial detergent. Using response surface models, the SAEW parameters required to clean stainless steel were optimized at 9.9 min for the treatment time, 37.8 °C for the water temperature, and 60 mg/L for the available chlorine concentration; and were 14.4 min, 29.6 °C, and 60 mg/L for rubber gasket and PVC samples, respectively. After washing with the optimized parameter combination, bacteria and adenosine triphosphate on the three materials were almost non-detectable, indicating that SAEW has the potential to replace acidic detergents in CIP milking systems.

Cleaning and Bacteria Removal in Milking Systems by Alkaline Electrolyzed Oxidizing Water with Response Surface Design

2019 ◽  
Vol 62 (5) ◽  
pp. 1251-1258 ◽  
Author(s):  
Yu Liu ◽  
Chaoyuan Wang ◽  
Zhengxiang Shi ◽  
Baoming Li
Keyword(s):  
Water Treatment ◽  
Response Surface ◽  
Treatment Time ◽  
System Response ◽  
Surface Model ◽  
Response Surface Design ◽  
Surface Design ◽  
Response Surface Models ◽  
Surface Models ◽  
Bacteria Removal

Abstract. A wash cycle using an alkaline solution with a dissolved chemical detergent is a standard clean-in-place (CIP) process for cleaning milking systems. However, long-term chemical use may corrode equipment and create difficulties in wastewater treatment. This study investigated the potential for using alkaline electrolyzed oxidizing (EO) water as an alternative to alkaline chemical detergent for removal of microorganisms and adenosine triphosphate (ATP) on milking system materials. Laboratory trials were performed based on a Box-Behnken response surface design to assess the cleaning effect of alkaline EO water on three materials typically used in milking systems: stainless steel, rubber gasket, and polyvinyl chloride (PVC) hose. Results showed that alkaline EO water treatment was generally enhanced with increased treatment time, temperature, and pH, and their interaction effects were also observed in ATP removal. However, treatment time did not have a dominant role in cleaning PVC hose. Response surface models were developed to reliably predict detected microorganisms and relative light units (RLU) on the three materials after alkaline EO water treatment. Based on the response surface models, the three parameters for alkaline EO water cleaning were optimized as treatment time of 10.0 min, temperature of 61.8°C, and pH of 12, after which microorganisms and RLU were nearly undetectable. Alkaline EO water treatment with the optimized parameters had an equivalent or better cleaning ability compared to the commercial detergent, suggesting its potential as a cleaning and bacteria removal agent for milking systems. Keywords: Alkaline electrolyzed oxidizing water, Cleanliness, Milking system, Response surface model.

scholarly journals Bactericidal efficacy of slightly acidic electrolyzed water (SAEW) against Listeria monocytogenes planktonic cells and biofilm on food-contact surfaces

2022 ◽  
Author(s):  
Jianxiong Hao ◽  
Junyi Zhang ◽  
Xueqi Zheng ◽  
Dandan Zhao
Keyword(s):  
Stainless Steel ◽  
Treatment Time ◽  
Planktonic Cells ◽  
Electrolyzed Water ◽  
Log Reduction ◽  
Food Contact ◽  
Bactericidal Efficacy ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Glass Surfaces

Abstract In the present study, the bactericidal efficacy of slightly acidic electrolyzed water (SAEW) against L. monocytogenes planktonic cells and biofilm on food-contact surfaces including stainless steel and glass was systematically evaluated. The results showed that SAEW (pH of 5.09 and available chlorine concentration (ACC) of 60.33 mg/L) could kill L. monocytogenes on food-contact surfaces completely in 30 s, whose disinfection efficacy is equal to that of NaClO solutions (pH of 9.23 and ACC of 253.53 mg/L). The results showed that long exposure time and high ACC contributed to the enhancement of the disinfection efficacy of SAEW on L. monocytogenes on food-contact surfaces. Moreover, the log reduction of SAEW treatment presented an increasing tendency within the prolonging of treatment time when SAEW was used to remove the L. monocytogenes biofilm formed on stainless steel and glass surfaces, which suggested that SAEW could remove L. monocytogenes biofilm effectively and its disinfection efficacy is equal to (in case of stainless steel) or higher than (in case of glass) that of high ACC of NaClO solutions. In addition, the results of the crystal violet staining and scanning electron microscopy (SEM) also demonstrated that SAEW treatment could remove the L. monocytogenes biofilm on food-contact surfaces.

Elemental chlorine-free bleaching of North American hardwood kraft pulps: Evaluation of oxidant-reinforced extraction variables on overall bleaching optimization

TAPPI Journal ◽  
2013 ◽  
Vol 12 (10) ◽  
pp. 33-41 ◽  
Author(s):  
BRIAN N. BROGDON
Keyword(s):  
Response Surface ◽  
Chlorine Dioxide ◽  
North American ◽  
Yield Loss ◽  
Alkaline Extraction ◽  
Kraft Pulps ◽  
Pulp Bleaching ◽  
Response Surface Models ◽  
Elemental Chlorine ◽  
Surface Models

This investigation evaluates how higher reaction temperatures or oxidant reinforcement of caustic extraction affects chlorine dioxide consumption during elemental chlorine-free bleaching of North American hardwood pulps. Bleaching data from the published literature were used to develop statistical response surface models for chlorine dioxide delignification and brightening sequences for a variety of hardwood pulps. The effects of higher (EO) temperature and of peroxide reinforcement were estimated from observations reported in the literature. The addition of peroxide to an (EO) stage roughly displaces 0.6 to 1.2 kg chlorine dioxide per kilogram peroxide used in elemental chlorine-free (ECF) bleach sequences. Increasing the (EO) temperature by Δ20°C (e.g., 70°C to 90°C) lowers the overall chlorine dioxide demand by 0.4 to 1.5 kg. Unlike what is observed for ECF softwood bleaching, the presented findings suggest that hot oxidant-reinforced extraction stages result in somewhat higher bleaching costs when compared to milder alkaline extraction stages for hardwoods. The substitution of an (EOP) in place of (EO) resulted in small changes to the overall bleaching cost. The models employed in this study did not take into account pulp bleaching shrinkage (yield loss), to simplify the calculations.

EXPLOSIVE CLADDING OF ALUMINIUM 5052-STAINLESS STEEL 304

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Saravanan S ◽  
Murugan G
Keyword(s):  
Stainless Steel ◽  
Interfacial Microstructure ◽  
Bend Angle ◽  
Flyer Plate ◽  
Layer Formation ◽  
Molten Layer ◽  
Explosive Cladding ◽  
Plate Velocity ◽  
Stainless Steel 304 ◽  
Loading Ratio

This study addresses the effect of process parameters viz., loading ratio (mass of explosive/mass of flyer plate) and preset angle on dynamic bend angle, collision velocity and flyer plate velocity in dissimilar explosive cladding. In addition, the variation in interfacial microstructure and mechanical strength of aluminium 5052-stainless steel 304 explosive clads is reported. The interface exhibits a characteristic undulating interface with a continuous molten layer formation. The interfacial amplitude increases with the loading ratio and preset angle. Maximum hardness is observed at regions closer to the interface

Evaluation of the residual stress in stainless steel 304L hydraulically expanded joints

2020 ◽  
pp. 095440892096401
Author(s):  
Ying Hong ◽  
Xuesheng Wang ◽  
Yan Wang ◽  
Zhao Zhang ◽  
Yong Han
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Yield Strength ◽  
Residual Stresses ◽  
Heat Exchangers ◽  
Nuclear Power ◽  
The Finite Element Method ◽  
Power Stations ◽  
Stainless Steel 304 ◽  
Initial Clearance

Stainless steel 304 L tubes are commonly used in the fabrication of heat exchangers for nuclear power stations. The stress corrosion cracking (SCC) of 304 L tubes in hydraulically expanded tube-to-tubesheet joints is the main reason for the failure of heat exchangers. In this study, 304 L hydraulically expanded joint specimens were prepared and the residual stresses of a tube were evaluated with both an experimental method and the finite element method (FEM). The residual stresses in the outer and inner surfaces of the tube were measured by strain gauges. The expanding and unloading processes of the tube-to-tubesheet joints were simulated by the FEM. Furthermore, an SCC test was carried out to verify the results of the experimental measurement and the FEM. There was good agreement between the FEM and the experimental results. The distribution of the residual stress of the tube in the expanded joint was revealed by the FEM. The effects of the expansion pressure, initial tube-to-hole clearance, and yield strength of the tube on the residual stress in the transition zone that lay between the expanded and unexpanded region of the tube were investigated. The results showed that the residual stress of the expanded joint reached the maximum value when the initial clearance was eliminated. The residual stress level decreased with the decrease of the initial tube-to-hole clearance and yield strength. Finally, an effective method that would reduce the residual stress without losing tightness was proposed.

A Noncyclic Method for Determination of Accumulated Strain in Stainless Steel 304 Pressure Vessels

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Gongfeng Jiang ◽  
Gang Chen ◽  
Liang Sun ◽  
Yiliang Zhang ◽  
Xiaoliang Jia ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
Peak Stress ◽  
Pressure Vessels ◽  
Experimental Results ◽  
Elastic Domain ◽  
Ratcheting Strain ◽  
Stainless Steel 304 ◽  
Accumulated Strain

Experimental results of uniaxial ratcheting tests for stainless steel 304 (SS304) under stress-controlled condition at room temperature showed that the elastic domain defined in this paper expands with accumulation of plastic strain. Both ratcheting strain and viscoplastic strain rates reduce with the increase of elastic domain, and the total strain will be saturated finally. If the saturated strain and corresponded peak stress of different experimental results under the stress ratio R ≥ 0 are plotted, a curve demonstrating the material shakedown states of SS304 can be constituted. Using this curve, the accumulated strain in a pressure vessel subjected to cyclic internal pressure can be determined by only an elastic-plastic analysis, and without the cycle-by-cycle analysis. Meanwhile, a physical experiment of a thin-walled pressure vessel subjected to cyclic internal pressure has been carried out to verify the feasibility and effectiveness of this noncyclic method. By comparison, the accumulated strains evaluated by the noncyclic method agreed well with those obtained from the experiments. The noncyclic method is simpler and more practical than the cycle-by-cycle method for engineering design.

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