Roller Conveyer Research Articles

Degradation of Toxins Derived from Foodborne Pathogens by Atmospheric-Pressure Dielectric-Barrier Discharge.

Foodborne diseases can be attributed not only to contamination with bacterial or fungal pathogens but also their associated toxins. Thus, to maintain food safety, innovative decontamination techniques for toxins are required. We previously demonstrated that an atmospheric-pressure dielectric-barrier discharge (APDBD) plasma generated by a roller conveyer plasma device is effective at inactivating bacteria and fungi in foods. Here, we have further examined whether the roller conveyer plasma device can be used to degrade toxins produced by foodborne bacterial pathogens, including aflatoxin, Shiga toxins (Stx1 and Stx2), enterotoxin B and cereulide. Each toxin was spotted onto an aluminum plate, allowed to dry, and then treated with APDBD plasma applied by the roller conveyer plasma device for different time periods. Assessments were conducted using a competitive enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results demonstrate a significant time-dependent decrease in the levels of these toxins. ELISA showed that aflatoxin B1 concentrations were reduced from 308.6 µg/mL to 74.4 µg/mL within 1 min. For Shiga toxins, Stx1 decreased from 913.8 µg/mL to 65.1 µg/mL, and Stx2 from 2309.0 µg/mL to 187.6 µg/mL within the same time frame (1 min). Enterotoxin B levels dropped from 62.67 µg/mL to 1.74 µg/mL at 15 min, and 1.43 µg/mL at 30 min, but did not display a significant decrease within 5 min. LC-MS/MS analysis verified that cereulide was reduced to below the detection limit following 30 min of APDBD plasma treatment. Taken together, these findings highlight that a range of foodborne toxins can be degraded by a relatively short exposure to plasma generated by an APDBD using a roller conveyer device. This technology offers promising advancements in food safety, providing a novel method to alleviate toxin contamination in the food processing industry.

Application of a roller conveyor type plasma disinfection device with fungus-contaminated citrus fruits

Efficient methods to achieve the safe decontamination of agricultural products are needed. Here, we investigated the decontamination of citrus fruits to test the antifungal potential of a novel non-thermal gas plasma apparatus, termed a roller conveyer plasma instrument. This instrument generates an atmospheric pressure dielectric barrier discharge (APDBP) plasma on a set of rollers. Penicillium venetum was spotted onto the surface of the fruit or pericarps, as well as an aluminium plate to act as a control, before performing the plasma treatment. The results showed that viable cell number of P. venetum decreased with a decimal reduction time (D value or estimated treatment time required to reduce viable cell number by 90%) of 0.967 min on the aluminium plate, 2.90 min and 1.88 min on the pericarps of ‘Kiyomi’ (Citrus unshiu × C. sinensis) and ‘Kawano-natsudaidai’ (C. natsudaidai) respectively, and 2.42 min on the surface of ‘Unshu-mikan’ (C. unshiu). These findings confirmed a fungicidal effect of the plasma not only on an abiotic surface (aluminium plate) but also on a biotic surface (citrus fruit). Further development of the instrument by combining sorting systems with the plasma device promises an efficient means of disinfecting citrus fruits during food processing.

Production of Low-Carbon Steel Sheet for Oil-Industry Pipe

The production of low-carbon, low-alloy steel coils for oil-industry pipe is considered from a metal-physics perspective. The selection of cooling conditions for the steel sheet and coils after rolling is of particular importance here. Analysis of the accompanying structure formation is based on thermokinetic diagrams plotted by means of data from a deformational dilatometer. To ensure the required mechanical properties and corrosion resistance of Severkor K52 steel sheet, the corresponding structural and phase composition is formed by appropriate laminar cooling of the strip on the roller conveyer at the exit from the broadstrip rolling mill. An industrial experiment permits the production of rolled sheet with the specified mechanical and operational properties on a 2000 rolling mill.

Mathematical Modeling of Cooling of a Continuously Cast Ingot for Reducing Heat Losses

We consider thermal processes running in the course of cooling of a continuously cast ingot in a continuous billet casting machine with regard for the heat of phase transformations. For the solution of the problem of rational utilization of the heat of melts, we propose to improve the technology of continuous casting of steel, which would make it possible to use the heat of the liquid core of an ingot for leveling the temperature field over its cross section and guarantee the minimum losses of the heat at the exit of the continuous billet-casting machine. We develop a mathematical model of cooling of continuously cast ingots in a two-dimensional space representation with regard for the release of the heat of crystallization in the two-phase zone. The numerical realization of the model is performed with the help of the implicit difference scheme of coordinate-wise splitting. The adequacy of the model is checked by analyzing the convergence of the experimental and numerical data according to the Fisher, Student, and Mann–Whitney criteria. In modeling, we simulated the control action in the zone of secondary cooling. It is established that, in the case of application of the control action in this zone, the surface temperature increases by 160°C, while the average mass temperature increases by 100–160°C. We choose criteria for the rational modes of cooling of continuously cast ingots. To preserve the heat content of an ingot, it is proposed to use heat insulation after the zone of water–air cooling. We determine relationships between the parameters affecting the surface temperature of the ingot and represent them in the form of nomograms. It is shown that, before the machine of gas cutting, as a result of heat insulation in the zone of air cooling, the ingot is thermostatted as a result of which the temperature of its most vulnerable zones (corners and surfaces) increases. It is established that, for the rational modes of casting of steels, the ratio of the length of the zone of heat insulation to the total length of the continuous billet casting machine varies within the range 0.3–0.6. To determine the heat losses in the process of subsequent cooling of the ingot in air after leaving the zone of machine gas cutting, according to the existing technology of transportation of slabs to compression, the time of modeling was set equal to 90–105 min. To preserve the heat content of the ingot and level temperatures over its cross section, it is also necessary either to use a thermally insulated transmission roller conveyer or to hold ingots in a thermostat.

Roller conveyer system for the reduction of pesticides using non-thermal gas plasma - A potential food safety control measure?

We previously described a novel roller conveyer plasma device, which generates gas plasma via atmospheric pressure dielectric barrier discharge, to disinfect vegetables in situ during the sorting process. Here, we tested this system to verify whether or not such treatment was also effective in pesticide reduction. Competitive enzyme-linked immunosorbent assay showed the pesticide malathion, present at levels typically observed on treated crops, was efficiently degraded to less than one tenth of the original level within 1 min. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) confirmed the decrease in the level of pesticide cocktail PL-14-2 and FA-2, including organophosphorus pesticides and other classes of pesticides, after plasma treatment. A cholinesterase inhibitory activity assay was used as an index to measure the activity of PL-14-2 and FA-2, which showed that the gas plasma treatment reduced the biological activity of the pesticides. In addition to its proven biocidal effects, our findings demonstrate the potential of this non-thermal plasma system as a food safety control measure ensuring reduction of pesticide residues in foodstuffs.

Depreciation of bearing blocks of rollers of roller conveyers of rolling mills

Essential increase in functional durability of a node of a roller of the roller conveyer of the rolling mill by the rational choice of parameters of the small-size shock-absorber (buffer adapter) is shown. At the same time dimensions of a node don’t change, costs of reconstruction are small. The possibility of management of loadings in a bearing node without change of technology parameters of the process which is carried out by the rolling mill is confirmed.

Production of hot-rolled sheet of specified quality by a new slab-casting technology

New methods of producing continuous-cast slab cannot be based on equilibrium crystallization of the steel at low speed. If melt is supplied to the wall layers in the mold through a pressurized submerged nozzle with eccentric outputs, the solidification rate of the steel in casting may be significantly increased. The results show that the new technology ensures improved quality in casting slabs of large cross section. When using the experimental nozzle, the width of the columnar-crystal zone is reduced and the disoriented-crystal zone is enlarged, while less axial segregation is observed. In casting by the new technology, heat transfer in the mold is increased by 10–12%. Impact tests reveal characteristics of the metal that are not evident in other tests. Structure formation of the metal in the continuous finishing group of a continuous broad-strip mill and subsequent strip cooling are studied by physical modeling. Tapered low-carbon steel samples taken from slab cooled on the intermediate roller conveyer of the broad-strip mill are rolled in one and two passes on a tworoller high-speed laboratory mill with a bypass unit. The rolling processes are geometrically and kinematically similar. After a fixed holding time in air, the rolled samples are set on one edge by means of a special device for partial quenching in coolant solution. Gradations of reduction are produced over the length of the sample, and gradations of cooling rate are produced over the width. The results of physical modeling illustrate the structure formation in low-carbon steel on rolling and accelerated strip cooling on a continuous broad-strip mill. Using these results and the Hall–Petch equation, specified structure and yield point of the final hotrolled sheet may be ensured. By eliminating the additional slab heating before rolling and improving the product quality, considerable economic benefit may be ensured.

A new roller conveyer system of non-thermal gas plasma as a potential control measure of plant pathogenic bacteria in primary food production

We have developed a novel roller conveyer plasma device, which generates gas plasma via atmospheric pressure dielectric barrier discharge (APDBP) on rollers. High voltage and earth electrodes are incorporated into the rollers, which are covered with a silicon sheet. Bactericidal activity of the device was measured against Xanthomonas campestris pv. campestris (Xcc), which was spotted onto aluminium plates and subjected to gas plasma treatment generated by APDBD. After treatment, viable cell number of Xcc decreased with a decimal reduction time (D value) of 0.90 min (initial population: 5.0 × 108 CFU/ml) and below 0.34 min (initial population: 9.8 × 105 CFU/ml). APDBD treatment induced slight morphological changes to Xcc along with significant degradation of lipopolysaccharides (LPS) and degradation/oxidation of genomic DNA to form 8-hydroxy-2'-deoxyguanosine (8-OHdG). Reactive chemical products (hydrogen peroxide, nitrite and nitrate), ultraviolet light (UV-A) and slight temperature elevations were observed during operation of the device. Our results suggest hydrogen peroxide and nitrite generated during operation of the device cause oxidation and degradation of the genomic DNA as well as the degradation of LPS, which are potential mechanisms for inactivation. In addition, the successful inactivation of Xcc on cabbage leaf by the device suggests the method could have practical applications.

Production of auto-body dual-phase steel with single-step cooling on the output conveyer of the 2000 continuous broad-strip mill at OAO NLMK

The goal is to produce hot-rolled dual-phase steel of strength class DP 450–600 at OAO Novolipetskii Metallurgicheskii Kombinat (NLMK). The steel’s final structure and properties is greatly affected by single-stage strip cooling on the output roller conveyer of the 2000 continuous broad-strip mill. The influence of the hot-rolling parameters on the structure and mechanical properties of the hot-rolled SPRC440R steel from which cold-rolled dual-phase steel is produced at OAO NLMK is studied in the laboratory. The temperatures and rates for accelerated cooling on the output roller conveyer of the 2000 continuous broad-strip mill at OAO NLMK are calculated by means of a mathematical model. The laboratory data and simulation results are used in developing trial conditions for industrial rolling. Recommendations are made regarding the production of hot-rolled dual-phase steel corresponding to strength class DP 450–600.

Temperature Holding Hood for Hot Charging of Continuous Casting Slab in Tangshan Iron and Steel Company

To improve the charging of high-temperature billets, it is crucial to produce them with zero defects and achieve effective insulation during their hot delivery. A mathematical model was developed based on the heat transfer characteristics of the billet during its hot delivery. The accuracy of the model was established by studying the thermal performance of the cover of the roller conveyer for small billets in Tangshan Iron and Steel Company. The results show that the cover of the roller conveyer of the continuous casting billet can effectively reduce the heat loss during the hot delivery of the billets, and the hot loading temperature was increased by 51.6 °C. The uniformity of the temperature of the casting billet section increased substantially. The temperature difference in the casting billet section was reduced by 120 °C. The heat preservation effects of temperature holding hoods of different materials were compared. It was found that the material of the temperature holding hood has slight effect on the heat preservation.

Precise Transhippment Control Of An Automated Magnetic-Guided Vehicle Using Optics Positioning

Abstract A parking position detection and control system is developed for precise transshipment of palletized materials between an automated guided vehicle (AGV) and a load transfer station. In order to align the roller conveyer of the AGV with that of the station, it is necessary for the AGV to detect the longitudinal, lateral and orientation deviations of its body with respect to the station. A pair of magnetic sensors is used to measure the lateral and orientation deviations of the AGV relative to a magnetic tape used as the guide-path. Fuzzy control is proposed to eliminate two deviations for path tracking that keeps the AGV on its path. A set of optics emitters and receivers is arranged on some specific points in the AGV and the station respectively to determine the longitudinal position for material transshipment, and to coordinate the transmission operation of two equipments. The experiment for the palletized materials transshipment shows that positioning control of our AGV parking system can achieve the accuracy, repeatability and reliability needed in industrial applications.

Nonuniform structure and properties in hot-rolled low-carbon steel coils

The austenite phase transitions in the industrial production of hot-rolled steel coils are studied magnetometrically. Nonuniformity of the structure and mechanical properties of low-carbon steel strip over its length and width may be attributed to incomplete phase transitions in the strip on the output roller conveyer and nonuniformity of the subsequent coil cooling in regular production conditions. Inheritance of the structural inhomogeneity formed after hot rolling may be responsible for the thickness variation observed after cold rolling of the strip. Recommendations are made for reducing or eliminating the structural inhomogeneity so as to improve product quality.

空気静圧軸受型ガラス基板搬送装置における薄板ガラスの浮上・変形特性

A non-contact aerostatic conveyer was recently proposed to quickly feed and inspect large glass substrates for liquid crystal display. The air conveyer supports the glass substrates by compressed air film and then feeds them through while keeping them clean compared to a conventional roller conveyer. The glass substrate in the latest generation is over 3 m square, and its thickness is less than 0.7 mm. Such thin and large glass substrates are expected to easily deform due to pressure distribution in the air film. Aim of this study is to investigate the levitation and deformation characteristics of glass substrates on a non-contact aerostatic conveyer with inherent orifice restrictors and to establish a calculation method to predict the glass sheet deformation with high accuracy. The deformation behavior of glass sheet on air film was investigated numerically by using the compressible Reynolds equation and Timoshenko's thin plate theory. Numerical results were compared with experimental ones to ascertain the validity of the calculation method. It was found that the glass sheet was easily deformed with a wavy shape by the pressure distribution of the air film. Experimental and numerical results showed almost the same trend.

Planning and Simulation Study of Stone Countertop Automatic Production Line

Current stone countertop production process is worn the following problems: long handling distance, long handling time, loose process cohesion, low balance rate, etc. In order to solve these problems, an automatic production line is proposed. In the production line, roller conveyer is used as the logistic system. The selected CNC equipment adopts an open structure and an oblique base. The equipments are arranged into a U-shape line combined with unit layout. In order to increase the flexibility of the production line, the whole production line is divided into two level modules. According to the design rules of the automatic production line, two examples are planned and are simulated based on EM-Plant. The simulation results show that, compared with the current production process, the automatic production line has the following advantages: the transit distance is shortened more than half, the transit time is reduced to about 1/7, and the balance rate increases by 20%, the output is nearly doubled, while the number of workers does not increase.

Production of K52–K60 steel with improved cold resistance on a 2000 hot-rolling mill

The production of cold-resistant steel sheet on the 2000 hot-rolling mill at OAO Magnitogorskii Metallurgicheskii Kombinat is considered. The dependence of the strip properties on the steel’s chemical composition and the conditions of hot rolling and accelerated cooling on the output roller conveyer is analyzed.

Deposits of excess carbonitride phase in microalloyed steel coils and sheet with different cooling conditions

Deposits of the carbonitrides (Ti, Nb)(C, N), Nb(C, N), and (Nb, V)(C, N) in the austenite and ferrite phases of X70 steel sheet after thermomechanical treatment are investigated. Nb(C, N) particles measuring up to 10 nm are seen in austenite in the final stage of rolling and after its conclusion prior to accelerated cooling of thick sheet. After intense accelerated cooling, most of the niobium and vanadium is retained in the solid solution, as confirmed by the vigorous deposition of (Nb, V)(C, N) particles measuring ∼2–4 nm in ferrite after tempering at 600°C. In coil production, the particles observed may be the result of general deposition or interphase deposition, depending on the cooling of the strip on the output roller conveyer of the continuous broad-strip mill. Carbonitride particles measuring 2–8 nm are deposited at winding temperatures of 550–570°C in steel with niobium and vanadium and at 590°C in steel without vanadium.

Development of High Precision Linear Transfer Platform using Air Floating System for Flat Panel Display Production and Inspection Process

Recently, there is an increasing requirement for high precision linear transfer platform using for flat panel display production and inspection process such as liquid crystal display, plasma display panel, and organic light-emitting diode. As next generation technology in the area of transfer platform, precision positioning and transfer flatness control under the 10m is required for inline process such as automatic optical inspection, surface treatment, and marking. As magnetic roller conveyer type is used as transfer platform for flat panel display, there are many problems such as contamination of panel by contact between roller and panel, deterioration of quality, and uncontrollable flatness. The requirements of the high precision linear transfer platform are high positioning accuracy and high transfer flatness. To satisfy these requirements, it has to be designed with the direct drive linear motion system and air floating system. In this work, linear transfer platform having air floating system is proposed, where moving system using linear motor is mounted at the inside of the air floating system, and air floating system is used for floating the flat panel display panel, control system are used for performance requirement. The developed high precision linear transfer platform is verified by performance test in the condition of 50mm step motion for 300mm stroke. From the performance test, positioning accuracy is measured as 4.6μm and repeatability is measured as 0.4μm. Velocity ripple is measured as 0.3% at transfer velocity of 100mm/sec. The transfer flatness is measured as 2.0μm, air gap is measured as 34.5μm in the condition of 1kg payload, and straightness is measured as 9.0μm. From the performance test, developed linear transfer platform is applicable for the flat panel display production and inspection process.

Heat-storing screens for broad-strip hot-rolling mills

Heat-trapping systems to moderate the cooling of components on the intermediate roller conveyer of broad-strip hot-rolling mills are considered. In terms of performance, Encomech panels are compared with Russian screens at the 2000 mills of OAO NLMK, OAO Severstal’, and OAO MMK, and also at the 1700 mill of PAO MMK im. Il’icha (Ukraine). Significant benefits of the Russian systems are noted.

Quality of Ст3сп steel reinforcement (class A500S) thermally hardened in a 280 mill

Thermal hardening of Ст3сп steel rolled in the 280 mill at the LPZ casting and rolling plant is developed, so as to produce reinforcement (diameter 14–18 mm) of strength class A500S according to the STO ASChM 7–93 standard. The strength of the metal, whether supplied to the mill in the hot or cold state, is the result of discontinuous quenching with variation in mean-mass self-tempering temperature within the range 565–575°C. The macrostructure, microstructure, and fine structure of the thermally hardened bar is investigated. The properties of the bar are ensured by the structure formed as a result of hardening and subsequent cooling on the roller conveyer and in the cooling unit: mainly tempered martensite in the surface layer; ferrite and cementite in the core of the bar.

A method for calculation of the shape of bent sheet glass transported on a roller conveyer

Based on the model developed by the Institute of Silicate Chemistry (ISC) of the Russian Academy of Sciences, a method is proposed for calculating the variations of geometrical parameters in bent sheet glass when transported on a roller conveyer. This method makes it possible to estimate theoretically not only the shape of the article after transportation, but also the process characteristics, based on the required deformation level.