Far-infrared Heating Research Articles

High efficiency far-infrared barrel heating control with excess heat prediction based on generalized predictive control in injection molding

Injection molding accounts for a huge share of the energy consumption of material processing. It has received considerable attention for its potential to enhance production efficiency, which relies on both product consistency and energy efficiency. Far-infrared heating, which has the advantages of high energy efficiency and low dissipation, has emerged as a promising heating technology in injection molding. However, the issue of low heat dissipation can lead to excess heat accumulation and cause substantial temperature errors. In this paper, a new barrel heating control method based on generalized predictive control (GPC) with real-time excess heat prediction model is proposed, in order to improve control accuracy and heating efficiency of far-infrared heating. A constrained multistep optimization combined with excess heat compensation is stated and an experimental platform is designed to validate the superiority of the proposed method under different operation scenarios. Experimental results show that the proposed method outperforms traditional proportional-integral-differential (PID) and GPC methods. Specifically, the proposed method can improve temperature control accuracy by 85.3 and 78.9 %, compared to PID and GPC, respectively. Such high temperature accuracy goes a long way in improving product consistency. Moreover, energy efficiency is improved, e.g., heating time is reduced by 42.7 and 16.5 %, energy consumption is reduced by 27.9 and 25.4 %, compared to PID and GPC, respectively. Control robustness is also verified under different operating conditions. In second-heating experiments, the temperature accuracy is improved by 84.4 % compared to PID. Therefore, the proposed method has the potential to enhance the production efficiency of injection molding.

Nanoengineered Laser Shock Processing Via Pulse Shaping for Nanostructuring in Metals: Multiscale Simulations and Experiments

AbstractModulating the heating and cooling during plastic deformation has been critical to control the microstructure and phase change in metals. During laser shock peening under optimal elevated temperatures, high-density dislocations and nanoprecipitates can be generated to greatly enhance material strength and fatigue life in metals. Currently, heating control during laser shock is limited to steady-state heat transfer, such as hot plate, irradiative heating, or far-infrared heating, which is slow for practical treatment and does not provide the transient conditions for generating nanostructures during shock processing. In this paper, we propose a general methodology to modulate the heating and cooling during laser shock processing via temporal pulse shaping, namely dual pulse laser shock peening (DP-LSP), which combines both ultrafast-heating and laser shock peening in one operation to generate desired microstructure and mechanical property. By modulating the duration of pulses as well as the spacing between pulses, different processing temperatures can be achieved. To test the feasibility of this novel process, DP-LSP has been applied to an Al matrix nanocomposite. Single pulse laser shock peening was able to remelt large second phase precipitates due to fast cooling, resulting in smaller grains (500 nm), while using DP-LSP with the appropriate pulse duration, dynamic precipitation effects can generate nanosized (30 nm) intermetallic phase Al3Ti with high density. By generation of grain size refinement, high-density nanoscale precipitates, and dislocations after DP-LSP, the yield strength increases by 18% and 102% compared with single pulse processing, and original sample respectively. Finite element method modeling was used to simulate the temperature profile in the alloy during the temporal modulated dual laser pulsing. A phase-field model and multiscale dislocation dynamics were applied to study dislocation dynamics and nanoprecipitation generation during DP-LSP, and their interactions at elevated temperatures. The work provides the basis for controlling microstructure in DP-LSP to enhance mechanical properties in metals.

Effects of a Graphene Heating Device on Fatigue Recovery of Biceps Brachii.

Far-infrared (FIR) is considered to be an ideal method to promote fatigue recovery due to its high permeability and strong radiation. In this paper, we report a flexible and wearable graphene heating device to help fatigue recovery of human exercise by using its high FIR divergence property. This study compares two different fatigue recovery methods, graphene far-infrared heating device hot application and natural recovery, over a 20 min recovery time among the male colleges' exhaustion exercise. Experimental results show that the achieved graphene device holds excellent electro-thermal radiation conversion efficiency of 70% and normal total emissivity of 89%. Moreover, the graphene FIR therapy in our work is more energy-efficient, easy to use, and wearable than traditional fatigue recovery methods. Such an anti-fatigue strategy offers new opportunities for enlarging potential applications of graphene film in body science, athletic training recovery, and wearable devices.

Crossover trial of the effects of a far-infrared heater that heats the feet with ceramic balls on autonomic nervous activity and mood states.

The accumulation of fatigue and stress creates problems, including reductions in quality of life and productivity. To investigate the effects of a far-infrared heater that heats the feet with ceramic balls on autonomic nervous activity and mood states. This study was performed as a crossover trial. Participants comprised 20 women. On different days, each participant underwent 15 min of foot warming with the far-infrared heater (far-infrared group) or remained seated for 15 min (control group). Autonomic nervous activity (low-frequency component/high-frequency component, high-frequency) and mood states scales (Profile of Mood States Second Edition and Two-Dimensional Mood Scale for Self-monitoring and Self-regulation of Momentary Mood States) during the study intervention were measured and compared between groups. Low-frequency/high-frequency was significantly higher in the control group 10 min after the start of intervention than at baseline (P = .033). Low-frequency/high-frequency was significantly lower in the far-infrared group than in the control group at 5 min (P = .027), 10 min (P = .011), and 15 min (P = .015). High-frequency was significantly higher in the far-infrared group at 5 min (P = .008), 10 min (P = .004), and 15 min (P = .015) than at baseline. High-frequency 5 min after the start of intervention was significantly higher in the far-infrared group than in the control group (P = .033). POMS2 scores improved significantly more in the far-infrared group than in the control group, including in fatigue-inertia (P = .019), tension-anxiety (P = .025), and total mood disturbance (P = .019). Finally, the far-infrared group showed greater improvements in Two-Dimensional Mood Scale-Short Term scores such as stability (P = .002) and pleasure (P = .013). Using the far-infrared heater to heat the feet with ceramic balls stabilized and improved mood, reduced Fatigue-Inertia and Tension-Anxiety, and alleviated total mood disturbance. Parasympathetic nervous system activation was observed from 5 min after the start of heating, suggesting that short-duration heat stimulation of the feet is effective.

Development of Vacuum-Steam Combination Heating System for Pasteurization of Sprout Barley Powder

The processing of sprout vegetables in powder form has been known to extend the shelf-life by retaining nutritional values; however, sprout powder products were exposed to a variety of contaminants, such as microbial contaminants, during processing and storage. Therefore, the proper treatment for removing the contaminants in the powder was required without compromising their quality properties. This study was conducted (1) to determine a suitable pasteurization method for sprout barley powder, and (2) to investigate the effect of vacuum-steam heating combination treatment on the quality change and the lethality of microorganisms in sprout barley powder. The heating pattern of sprout barley powder was elucidated with a vacuum-thermal combination system consisting of a vacuum chamber, overhead stirrer, far-infrared heater, and PID (Proportional-Integral-Differential) controller. In addition, the mixing patterns of sprout barley powder, depending on the types of stirring blades, were evaluated by discrete element modeling using EDEM™ software. The vacuum-steam combination heating system was fabricated using the investigated pre-design factors. The quality change in sprout barely powder was evaluated by measuring the microbial inactivation, CIE values (L*, a*, b*, ΔE), and water activity (aw). During the pasteurization process, steam could be directly injected into the chamber at regular intervals for two hours to transfer moisture and heat to the powder. By combining steam and vacuum conditions, the population of E. coli O157:H7 in the powder was reduced by 4.33 log CFU/g, eliminating all E. coli O157:H7 in the powder. In addition, the water activity (aw) of the powder was significantly decreased in a vacuum pressure environment without the quality deterioration.

Cost-effective occupation dependant infrared zonal heating system for operational university buildings

Recent legislations have necessitated policies for carbon print reduction. Buildings and in particular space heating are major energy consumers and responsible for over 34% of carbon print. This work presents a method of heating only certain parts of the building using far infrared (FIR) heating. This study gives an overview on the application of infrared radiation in heating by modern methods in tune and compatibility with climate developments for the public spaces in this decade. The case study is on a university lecture theatre and the space is split up into varyingly sized zones which enable different parts of the room to be heated depending on the time and occupation of the zone. The potential to heat each zone with FIR is implemented which runs according to the machine learning algorithm (MLA) through a practical study of real CO2 data collection and validation. This allows heating to start running before the zone(s) is occupied to optimise thermal comfort. Results show that occupation zone FIR heating saves an average of 11.175kWh through various occupations compared to the currently equipped convection wall mounted radiators. Occupation forecasting of the room using random forest machine learning has an accuracy of 97.75% for 15-minutes intervals of a day. Cost analysis for the proposed occupation heating show savings of up to 76% and 14.6% compared to convection electric and gas heating respectively. FIR provides a more efficient method of heating with the capacity for zonal implementation. The results in this research demonstrate the feasibility of FIR zonal heating for non-domestic applications.

Warming performance of far infrared lights electrogenerated by carbon nanotubes composite fabrics

Carbon nanotubes (CNTs) composite fabric was prepared with filament yarns coated by CNTs. CNTs composite fabric could obviously emits far-infrared light just driven by 5 V power. The proportion of life light (4–16 µm wavelength) in the total infrared radiation was more than 85%, which suggested that CNTs composite fabric are highly efficient at converting electrical energy into far-infrared light that can be absorbed by human body. The CNTs composite fabrics could be heated appreciably by using a 5 V mobile power supply, which brought waistcoat with active heat preservation. Under cold environment, the energy required for maintaining normal body temperature in far-infrared heating region is significantly lower than that in non-far-infrared heating region. The result indicated that the CNTs composite fabrics with far-infrared heating effect are particularly suitable for making clothing worn in cold regions, which realized the unity of warmth and lightness.

Drying features of microwave and far-infrared combination drying on white ginseng slices.

In this study microwave and far-infrared combination drying were conducted to investigate the effect of microwave and far-infrared heating mode switching point water content (SW), ginseng slice thickness, and far-infrared drying temperature on drying indicators (surface colour difference, ginsenosides content, and surface shrinkage rate) and drying efficiency (drying time) during the process of drying white ginseng slices. Regarding microwave drying, the microwave drying time cannot exceed 150s, and the ginseng slice water content cannot be less 50%. For the combination drying, SW, far-infrared drying temperature and slice thickness increased, the colour difference and surface shrinkage rate first decreased and then increased, and the content of ginsenosides first increased and then decreased. In addition, the combination drying showed faster drying rate, higher ginsenosides contents value, colour difference (ΔE) value and lower surface shrinkage rate than single far-infrared drying.

Development of multifunctional warming fabric part II: Multi-quality process parameter optimization of hygroscopic heating and antistatic function yarn

This series study develops a multifunctional poly(ethylene terephthalate) (PET) fabric with far-infrared function and moisture absorption heating properties for warming clothing. In Part I, the far-infrared function yarn was made by a PET and nano-germanium composite to improve the properties of far-infrared emissivity and far-infrared heating. The moisture absorption heating PET yarn includes hygroscopic heating and antistatic properties. In Part II, this moisture absorption heating PET yarn is made by the hydrophilic PET, and the process parameters optimization for melt spinning is presented. First, in order to improve the hydrophilicity of PET, the modified PET is polymerized by terephthalic acid, ethylene glycol, polyethylene glycol oligomers, and sodium-5-sulfo-bis-(hydroxyethyl)-isophthalate. Then, the hydrophilic PET is made into a moisture absorption heating PET yarn, specified to a 75d/72f fully drawn yarn by melt spinning. The properties of this yarn, including hygroscopic heating, surface resistance, tensile strength, elongation at break and yarn count, are presented. In order to improve the properties of this yarn, the Taguchi method combined with grey relational analysis is used to obtain the optimal multi-quality process parameters for melt spinning. According to experiment results, this modified yarn has excellent hygroscopic heating, surface resistance and elongation at break. At the same time, it is shown that the warming fabric forms from Part I and this modified yarn can achieve far-infrared emission of 89%, far-infrared heating of 6.3 ℃, hygroscopic heating of 1.8 ℃ and surface resistance of 107Ω.

Development of multi-material two-photon microfabrication using multiple droplets manipulation by far-infrared ring heating

Development of multi-material two-photon microfabrication using multiple droplets manipulation by far-infrared ring heating

Evaluation of the immunobiological effects of a regenerative far-infrared heating system in pigs.

Thermal conditions are an important environmental factor in maintaining healthy pigs because they affect feed intake, growth efficiency, reproduction and immune responses in pigs. RAVI, a regenerative far-infrared heating system, can effect pig production by emitting an optimal far-infrared wavelength. Far-infrared radiation has been reported to increase microvascular dilation and vascular flow volume. The purpose of this study was to evaluate the immunobiological differences between pigs raised with the RAVI system and the gasoline heater system. Twenty-six-week-old weaned pigs were raised in two rooms that were equipped with a RAVI system or a gasoline heater for 8 weeks. A porcine atrophic rhinitis vaccine was administered after two weeks and transcriptome analysis in whole blood were analyzed at 2-week intervals. Signaling pathway analyses of the RAVI group at 8 weeks showed the activation of pathways related to nitric oxide (NO) production. This suggests that the application of RAVI might induce the production of NO and iNOS, which are important for increasing the immune activity. Similar to the result of microarray, phenotypic changes were also observed at a later period of the experiment. The increase in body weight in the RAVI group was significantly higher than the gasoline heater group at 8 weeks. The antibody titer against the vaccine in the RAVI group was also higher than that the gasoline heater group at 4 weeks and 8 weeks. This evaluation of the use of a far-infrared heating system with pigs will be helpful for applications in the pig farm industry and pig welfare.

Development of a warming multi-functional fabric Part I: The analytic hierarchy process combined with the technique for order preference by similarity to an ideal solution for the optimization of the multi-quality melt spinning parameters in far-infrared functional yarn

This series study develops a multi-functional yarn with far-infrared emission, heating, and antistatic properties for winter clothing. In Part I, polyethylene terephthalate (PET) is used as the polymer matrix, and nano germanium powder is uniformly mixed with PET by the melt blending process for modification, in order that the PET composite has far-infrared function. Afterwards, the modified PET is made into 75d/72f fully drawn yarn (FDY) by melt spinning and melt drafting. The properties of the yarn, including tensile strength, elongation at break, yarn count (in denier), far-infrared emissivity, and far-infrared heating are discussed. In order to optimize the quality of yarn in the melt spinning process, this study designs process parameters consisting of germanium powder addition, melt temperature, mold temperature, nozzle temperature, gear pump speed, and take-up speed using the Taguchi method. Then, the analytic hierarchy process (AHP) is applied to obtain the weights of each quality, which will be used in the technique for order preference by similarity to an ideal solution (TOPSIS) to obtain the optimal processing parameters for multi-quality yarn. The results show that the tensile strength of the optimized modification PET yarn is 4.84 g/d, the elongation at break is 41.26%, yarn count is 74.39d/72f, the far-infrared emissivity is 89% and the far-infrared heating is 6.3℃. The properties of the optimized modified yarn are obviously better than general PET yarn.

Effects of Prior Freezing Conditions on the Quality of Blueberries in a Freeze-Drying Process

Abstract. Freeze-drying has played an increasingly important role in the production of dehydrated foods. This article discusses the operating conditions of the prior freezing process of blueberry fruit to maintain the fruit aroma during the sublimation process. The properties of frozen fruit, such as ice crystal size, seem to depend on the freezing speed, leading to some aroma loss during the sublimation process. The temperature of the deep freezer was set at -20°C, -40°C, -60°C, or -80°C to determine the effects of changing the freezing speed of blueberries during prior freezing. Northern highbush blueberry cultivars Dixi and Elliott harvested in a university orchard (Tokyo, Japan) were used as the test material. The sublimation process of freeze-drying was done using a transparent vacuum desiccator connected to a vacuum pump through a vapor cooling trap under heating conditions provided by a far-infrared heater. Trapped vapors were analyzed with GC-MS to identify and quantify the aroma compounds of the blueberries, such as benzaldehyde. The change in the appearance of the freeze-dried blueberries following prior freezing at various speeds is also described. The amounts of typical volatile compounds, such as acetic acid, 2-hexanol, and 3-hexanol, decreased as the freezing speed increased. Most volatile aroma compounds could be preserved when blueberries were frozen rapidly in a deep freezer. Keywords: Aroma loss, Blueberry, Freeze drying, Freezing speed, Prior freezing.

Effects of Far-Infrared Irradiative Heating Pasteurization on Fungi

The effect of far-infrared (FIR) irradiation pasteurization on fungi was quantitatively evaluated and compared with the effect of thermal conductive heating. After the bulk temperature of the sterile saline irradiated by FIR reached a steady given temperature, yeast cells (Candida albicans NBRC 1950 and Saccharomyces cerevisiae NBRC 1067) or fungal spores (Aspergillus niger NBRC 4781) were inoculated and FIR heating was conducted. A mullite cylinder FIR heater, with a main wavelength of 4 - 7 μm, was used for FIR heating. Death of fungi by FIR heating and by thermal conductive heating both followed first-order reaction kinetics, and the apparent death rate constants under different temperature conditions were obtained. For the same bulk temperatures, pasteurization by FIR heating was more effective than thermal conductive heating. The activation energy for the death of fungi by FIR irradiation was slightly lower than thermal conductive heating, indicating differences in the mechanism of action.

Comparison of Browning Colour Formation on the Surface of Fish Samples during Grilling

A comparison of the browning of fish species grilled using far-infrared (FIR) heating was evaluated. Japanese amberjack (Seriola quinqueradiata), Japanese Spanish mackerel (Scomberomorus niphonius), salmon (Oncorhynchus masou), and red sea bream (Pagrus major) were used. Temperature and colour (CIE L*, a*, and b* values) of the sample surface were monitored over time. The rate of L* change was evaluated by treating the browning reaction as a first-order reaction. Colour changes based on a* and b* values were correlated with L* values using empirical equations. During browning, the trajectories of sample colour changes followed almost the same pattern, except for salmon, which was probably due to astaxanthin content. Samples with higher fat content browned faster, according to their higher frequency factor (k0) of the browning rate. An empirical equation for k0 prediction based on sample fat content was obtained, giving fairly good approximations to measured values.

Far-Infrared-Assisted Preparation of a Graphene-Nickel Nanoparticle Hybrid for the Enrichment of Proteins and Peptides

A new approach based on far infrared-assisted in situ reduction was developed for the facile one-step preparation of graphene-nickel nanoparticle hybrid by refluxing a mixture solution containing graphene oxide, nickel(II) sulfate, and hydrazine over an far-infrared heater. The reduction time was as short as 20 min. The structure of the material was investigated by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, energy dispersive spectroscopy, vibrating sample magnetometery, and Fourier transform infrared spectroscopy. Magnetic investigations indicate that the grapheme-nickel nanoparticle hybrid exhibits ferromagnetic behavior at room temperature. Meanwhile, the hybrid was successfully employed in the enrichment and identification of proteins and peptides in combination with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry based on its excellent magnetic responsibility, high dispersibility, large surface area, and hydrophobicity, indicating great promise for a wide range of applications.

Research on Welding Technology of the Belt Conveyor Roller

In view of the fracturing occurred at the welded joint of the belt conveyor roller while being in use in a coal mine of Fujian Province, the paper analyses the roller’s structure and stress in the basis of the transmission principle. It explores the reasons of the fracturing problem, and then proposes method to improve the roller’s welding technology. These are the cause of the roller fracturing，which the tension of the belt is great, and the roller itself is not strong enough, and welding process of steel plate is poor, and welding quality is not high. Use CO2 and Ar mixed gas shielded arc welding to do backing weld, then use the welding method of automatic submerged arc welding. Finally the tempering to the welded joint part with the track-type far-infrared heater eliminate the welding residual stress. By actual use, it’s proved that the Welding Process Improvement is feasible, reasonable, reliable and practical.

Investigation of Carbonization Energy for Waste Biomass in Superheated Steam Combined with Far-infrared Heating

This study aimed to investigate the carbonization rate and energy for carbonization of granular waste biomass by superheated steam (SHS) treatment combined with far-infrared heating (FIH) (SHS＋FIH). Cooked and dried rice grains were used as a sample. Carbonization temperatures ranging from 503 to 578K were adjusted by combining SHS temperatures with FIH temperatures. Carbonization rate determined by changes of sample weight during carbonization treatment depended on the carbonization temperature and obeyed the Arrhenius equation. The energy requirement per unit mass of carbonized product, Qc, decreased as carbonization temperature increased. In the combined treatment of SHS＋FIH, the apparatus heated easily and rapidly to the carbonization temperature only when 1/6～ 1/7 of heat flow (thermal energy rate) to generate SHS was supplied to the FIH heater, and the warm-up time of the apparatus decreased to about half that of the treatment with SHS alone. Results of the increase in productivity of the carbonized product and decrease in carbonization energy as carbonization temperature increased confirmed the energetic advantages of the combined treatment of SHS＋FIH. At carbonization temperatures higher than 623K, it is estimated that the combustion heat of the carbonized product would be several times higher than the

EFFECT OF FAR-INFRARED HEATER ON THE PHYSICOCHEMICAL CHARACTERISTICS OF GREEN TEA DURING PROCESSING

ABSTRACT The green tea leaves (Camellia sinensis var. sinensis) were irradiated by a far-infrared (FIR) heater during the roasting and drying step, resulting in three different treatments produced. Green tea was extracted by soaking the leaves in water, and the components were analyzed. FIR irradiation, combined with fryer heating during the roasting step and additionally applied after the drying step, increased total phenolic contents of green tea from 116.30 to 171.77 mg/g, and total flavanol contents from 17.54 to 24.76 mg/g, compared with the non-irradiated control. Ascorbic acid contents also increased from 3.07 to 4.20 mg/g. The amounts of epicatechin gallate and epigallocatechin gallate were significantly increased from 2.41 to 4.59 mg/mL and 20.61 to 28.54 mg/mL, respectively, compared with the non-irradiated control. FIR irradiation increased Nitrite Scavenging Ability of green tea at pH 3.0 and pH 4.2, while there was no significant difference at pH 6.0. Sweetness, umami and aroma of green tea were enhanced by FIR irradiation, while bitterness and astringency were decreased compared with those of the control. These results show that FIR heating during the green tea process affected the chemical properties of green tea, and the FIR heater can be applied to increase the physicochemical qualities of green tea. PRACTICAL APPLICATIONS Green tea, a widely consumed drink, has received much attention because of the beneficial biological effects attributable to its excellent antioxidant activity. In this article, a far-infrared (FIR)-heater for industrial application was used during the processing of green tea leaves, and the chemical characteristics and quality of FIR-treated green tea were determined. FIR irradiation, combined with fryer heating during the roasting step and additionally applied after the drying step, significantly increased phenolic, flavanol, ascorbic acid, epicatechin gallate, epigallocatechin gallate contents and nitrite-scavenging activity compared with non-irradiated control. Sensory evaluation also showed a positive effect of FIR irradiation. The results indicated that FIR heater could be easily applied to increase the quality of green tea in the processing line.

Preliminary results of M-VAC chemotherapy combined with mild hyperthermia, a new therapeutic strategy for advanced or metastatic transitional cell carcinoma of the urothelium

We evaluated the efficacy and safety of M-VAC chemotherapy combined with mild hyperthermia, a new therapeutic strategy for advanced metastatic transitional cell carcinoma of the urothelium. The subjects were 12 patients diagnosed with advanced metastatic transitional cell carcinoma of the urothelium. For mild hyperthermia, the patients' oral temperature was elevated to about 38 degrees C by heating for 20 min and retaining the heat for 20 min with a far-infrared heater. The antitumor effect was evaluated according to the RECIST, while adverse drug reactions were assessed based on the NCI-CTC. The antitumor effect was rated as partial remission (PR) in 10 of the 12 patients and stable disease in 2 patients, with an efficacy rate of 83% (10/12). All 10 patients who had achieved PR received three courses of treatment. Of the 12 patients, 5 died during the observation period, with survival for 9-23 months (mean: 15.6 months). Adverse drug reactions included myelosuppression in all patients (Grade 3 in 4 patients, Grade 4 in 8), and gastrointestinal toxicity, such as nausea or vomiting, which was mild (Grade 0 in 2 patients, Grade 1 in 8, Grade 2 in 1, Grade 3 in 1). The results of the present study suggest that M-VAC chemotherapy combined with mild hyperthermia, which potentiates the anticancer effect and reduces adverse drug reactions such as gastrointestinal symptoms, is a useful and safe method for the treatment of advanced transitional cell carcinoma of the urothelium.