Improving quality of maintenance task for milk powder manufacturing unit through TOPSIS

PurposeThe purpose of this paper is to explore the possibilities of improving the quality of existing maintenance task of the atomizer of milk powder manufacturing unit of a dairy plant. Looking to the past business volume and expected growth, the milk powder manufacturing unit forms a noticeable sector of processing plant. The lack of quality in maintenance standards leads to reliability losses of about 20–25% with low productivity and profit. Such facts and challenges of keeping the system in ready-state motivate a definite maintenance plan to be modeled based on a live failure analysis to be executed during shutdown or scheduled period.Design/methodology/approachThe deliverables are achieved by collecting the historical failure data i.e. downtime and failure frequencies; from January 2020 to July 2020 at Dudhsagar dairy, Gujarat, India. Reliability modeling is done in a view to understand the failure pattern behavior of the milk powder manufacturing unit. The atomizer is discriminated as a critical component based on these data and their functional failures, failure causes, effects and repercussions of failures with existing control and maintenance practices has been modeled based on live shop-floor study. Scores are assigned on 1 to 10 levels by analyzing attributes effects from lowest to highest concern respectively for every modes of failure through realistic brain-storming among maintenance team by incorporating some advanced attributes like maintainability, economic safety, economic cost and spares with basic criteria in this study. The maintainability criticality index (MCI) is narrated by these score values through multi-attribute decision-making (MADM) based failure analysis models like Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS).FindingsThe primary findings of this research work are to propose improvements in the quality of the maintenance plan of critical component like; atomizer of a milk powder manufacturing unit which is commonly representing critical component in a major range of industrial processes. The case study recommended four silent maintenance strategies i.e. scheduled maintenance scheduled discard, scheduled failure finding and redesign as a qualified maintenance plan for the atomizer based on MCI and rankings of its potential failure causes. The results are helpful in upgrading quality standards for the maintenance activities of a process industry of alike or of dissimilar kinds in accordance with the failure analysis.Originality/valueOriginality mainly consists of investigating the scope of enhancing the existing maintenance practices through actual failure analysis with the help of TOPSIS. The criteria employed in this study are probability of chances of failure, degree of detectability and degree of severity as basic criteria along with some advanced criteria like; maintainability, spare parts, economic cost, economic safety are selected based on the outcome of shop-floor study and reliability modeling. The notable past failure statistics (downtime, frequency of failures) of a milk powder manufacturing unit were recorded and these data are analyzed based on reliability to extract an explicative component i.e. atomizer.

Active participation of industrial enterprises in electricity markets - a generic modeling approach

Industrial enterprises represent a significant portion of electricity consumers with the potential of providing demand-side energy flexibility from their production processes and on-site energy assets. Methods are needed for the active and profitable participation of such enterprises in the electricity markets especially with variable prices, where the energy flexibility available in their manufacturing, utility and energy systems can be assessed and quantified. This paper presents a generic model library equipped with optimal control for energy flexibility purposes. The components in the model library represent the different technical units of an industrial enterprise on material, media, and energy flow levels with their process constraints. The paper also presents a case study simulation of a steel-powder manufacturing plant using the model library. Its energy flexibility was assessed when the plant procured its electrical energy at fixed and variable electricity prices. In the simulated case study, flexibility use at dynamic prices resulted in a 6% cost reduction compared to a fixed-price scenario, with battery storage and the manufacturing system making the largest contributions to flexibility.

The Method of Computing Diameter of Nano Wood Powder Based on Geometric Figure Fitting

Computing the diameter of nanometer wood powder is the key step of intelligently acquiring wood powder mesh during processing and production in the wood powder manufacturing industry. To obtain the micro image of nano wood powder, the method of hole filling is adopted to fill the binary image of wood powder particles. The contours of wood powder particles are extracted with the use of the edge detection operator, and the control experiment is carried out accordingly. The shape line method is adopted while fitting the geometric shape of wood powder particles, and the longest side or diameter of the figure is solved so as to obtain the diameter. In addition, based on the conversion standard, the mesh number of particles is calculated. The method presented in this study is expected to facilitate the automation of wood powder pellet processing industry, whereas the method is also found to have optimal applicability and reference significance for the measurement of other sorts of particles.

Mechanical strength characterization and modeling of hydroxyapatite/tricalcium phosphate biocomposite using the diametral-compression test

This study reports the enhanced mechanical resistance of the composite bioceramics of hydroxyapatite (HAP) and tricalcium phosphate (β-TCP) used as bone substitute. HAP/β-TCP mixture was prepared by wet mixing of powders and characterized. Effects of powder manufacturing and sintering temperature on the densification, microstructure and mechanical properties of the composite were studied. The rupture strength (σr) was calculated using the Brazilian test. At 1250 °C, the relative density and mechanical strength of the HAP/β-TCP ceramics reached the maximum value of 89% and 43 MPa, respectively. Experimental results were modeled by the finite element method to determine the stress distribution in the compacted disc.

Influence of Incubation Temperature and Total Dissolved Solids on Biofilm and Spore Formation by Dairy Isolates of Geobacillus stearothermophilus

ABSTRACT Geobacillus species are important contaminants in the dairy industry, and their presence is often considered an indicator of poor plant hygiene with the potential to cause spoilage. They can form heat-resistant spores that adhere to surfaces of processing equipment and germinate to form biofilms. Therefore, strategies aimed toward preventing or controlling biofilm formation in the dairy industry are desirable. In this study, we demonstrated that the preferred temperature for biofilm and spore formation among Geobacillus stearothermophilus A1, D1, P3, and ATCC 12980 was 65°C. Increasing the total dissolved milk solid concentration to 20% (wt/vol) caused an apparent delay in the onset of biofilm and spore formation to detectable concentrations among all the strains at 55°C. Compared to the onset time of the biofilm formation of A1 in 10% (wt/vol) reconstituted skim milk, addition of milk protein (whey protein and sodium caseinate) caused an apparent delay in the onset of biofilm formation to detectable concentrations by an average of 10 h at 55°C. This study proposes that temperature and total dissolved solid concentration have a cumulative effect on biofilm and spore formation by G. stearothermophilus A1, D1, P3, and ATCC 12980. In addition, the findings from this study may indicate that preconditioning of stainless steel surfaces with adsorbed milk proteins may delay the onset of biofilm and spore formation by thermophilic bacteria during milk powder manufacture. IMPORTANCE The thermophilic bacillus Geobacillus stearothermophilus is a predominant spoilage bacterium in milk powder manufacturing plants. If its numbers exceed the accepted levels, financial losses may be incurred because of the need to lower the price of the end product. Furthermore, G. stearothermophilus bacilli can form heat-resistant spores which adhere to processing surfaces and can germinate to form biofilms. Previously conducted research had highlighted the variation in the spore and biofilm formation among three specific strains of G. stearothermophilus isolated from a milk powder manufacturing plant in New Zealand. The significance of our research is in demonstrating the effects of two abiotic factors, namely, temperature and total dissolved solid concentration, on biofilm and spore formation by these three dairy isolates, leading to modifications in the thermal processing steps aimed toward controlling biofilm and spore formation by G. stearothermophilus in the dairy industry.