Hot Air Blower Research Articles

Uji Kinerja Alat Pengering Tipe Batch Dryer untuk Pengeringan Kakao (Theobroma cacao L.) dengan Sistem Penghembus Udara Panas

Cocoa is a superior export commodity for Indonesia. Lampung is one of the largest cocoa producing regions in Indonesia. In processing cocoa beans, drying is the most important factor for quality. The causes of the low quality of cocoa beans include unfermented cocoa beans before drying and the conventional drying process. Drying of cocoa can be done using a bacth type dryer with a hot air blower system with a large enough capacity that has been built on offer. This study aims to examine the performance of batch type cocoa dryers with hot air blowing systems. The method used in this study is an experimental and descriptive method that uses cocoa with different initial moisture content, namely 36.62%, 42.20%, and 32.61%. The results showed that the batch type dryer produced plenum temperature of 590 C, 580 C, 620 C and the temperature of the material that was 500 C, 500 C, and 510 C. The higher the temperature used, the faster the drying time and the lower the initial temperature of cocoa the faster the drying process. Rubber wood fuel used in each test is 101 kg, 123 kg, 95 kg. Drying time for all three tests is 10 hours, 11 hours, and 10 hours. The efficiency of drying using batch type dryer is 26.01%, 26.75%, 25.52%. The weight of 1 kg of rubber wood on average can dry 5 kg of wet cocoa Keywords: Bath Type Dryer, Cocoa, Moisture Content, Temperature.

Identification of heat exchanger process through Hammerstein and polynomial models

Process industries extensively use heat exchangers in their operations, playing a crucial role in various sectors by facilitating efficient heat transfer, conserving energy, and reducing operational costs. This paper focuses on identifying and validating the system model, with the primary task of designing the controller involving the determination of the mathematical representation of the system. The First Order Plus Dead Time (FODT) model, derived from basic principles, is used to represent the system. To analyze the system’s behavior and construct a suitable controller, model development is essential, achieved by constructing principles models using energy balance equations to identify the heat exchanger process. Data collected from the model are utilized in the identification process, with the temperature at the outlet of the hot air blower being the controlled variable in this investigation. The research aims to determine the mathematical model based on time versus temperature data acquired from the Heat Exchanger. Various system identification methods, such as Hammerstein Wiener (HW), Auto Regressive with Exogenous Input (ARX), Box-Jenkins (BJ), Output-Error (OE), and Auto Regressive Moving Average with Exogenous Input (ARMAX) models, are implemented for the heat exchanger. The models obtained undergo validation, and the best-fit model closest to the physical system is considered for controller design. After conducting the analysis, it was found that the Output-Error (OE) model outperforms other models in terms of achieving the best fit.

Optimization of different drying methods and its impact on antioxidant potential of Ocimumbasilicum L.

In the present study, the effect of different drying methods (sun drying, shade drying, oven drying at 35 °C, 45 °C, 55 °C and hot air blower drying) was assessed to optimize the essential oil (EO) quality of Ocimumbasilicum L. The fresh and dried samples were hydrodistilled using a Clevenger apparatus to extract the EO. The EO composition was determined by GC and GC–MS techniques. The antioxidant activity was measured using 2, 2- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity; FRAP activity and Fe2+- ferrozine test system for iron chelating activity methods. The content of iron, copper, zinc and manganese were analyzed by Atomic Absorption Spectrophotometer (AAS). Sun dried O.basilicum showed the highest EO yield (0.8%, v/w). Linalool (10.67–32.91%) and methyl chavicol (16.24–58.00%) were present as the major components in all the EOs being the highest for blower dried and shade dried samples respectively. EO obtained from the shade dried material was showing the highest antioxidant potential followed by blower dried plant sample. Dried material exhibited higher micronutrient content as compared to the fresh one. The shade drying method can be a good option for obtaining the best quality essential oil from O.basilicum in terms of the major component and antioxidant potential.

On-Site Application of End-Grain Bonded Timber Under Low Curing Temperatures

The end-grain bonding of timber components using the Timber Structures 3.0 technology (TS3) is an advancing construction method in timber engineering. This technology allows the realisation of any plate size by bonding plates on-site where low temperatures influence the performance. Therefore, investigations are underway to evaluate the influence of the low temperatures on the curing process. Additionally, research is in progress to discover techniques to reduce any adverse effects of low curing temperatures on the mechanical properties of the bond. The implementation of particular measures, such as the inclusion of milled heating wires into the joint and the pre-heating of the joint with a hot air blower, has been identified as advancing the potential for grouting even in the face of low external temperatures, as recent research has indicated.

Effects of electromagnetic roller-hot-air-steam triple-coupled fixation on reducing the bitterness and astringency and improving the flavor quality of green tea.

Despite the importance of fixation in determining green tea quality, its role in reducing the bitter and astringent taste of this beverage remains largely unknown. Herein, an electromagnetic roller-hot-air-steam triple-coupled fixation (ERHSF) device was developed, and its operating parameters were optimized (steam volume: 20kg/h; hot-air temperature: 90°C; hot-air blower speed: 1200 r/min). Compared with conventional fixation treated samples, the ratio of tea polyphenols to free amino acids and ester-catechins to simple-catechins in ERHSF-treated samples was reduced by 11.0% and 3.2%, reducing bitterness and astringency of green tea; amino acids, soluble sugars, and chlorophyll contents were significantly increased, enhancing the freshness, sweetness, and greenness; the color indexes, such as L/L* value of brightness and -a/-a* value of greenness, were also improved, and ERHSF-treated samples had the highest sensory scores. These results provided theoretical support and technical guidance for precise quality improvement of summer-autumn green tea.

Dynamic acoustoelastic testing (DAET) with a thermal strain pump for characterization of closed fatigue cracks

Dynamic acoustoelastic testing (DAET) is a nonlinear acoustic technique used to characterize the nonlinear elastic behavior of materials. To enable the in-situ implementation of DAET, we propose a modification to the conventional DAET setup by replacing the mechanical strain pump with a thermal strain pump. This study presents the feasibility of the proposed thermal-pump DAET setup for in-situ detection of closed fatigue cracks in an aluminum test specimen. Our setup employs a hot air blower to induce a small (∼4 °C) thermal gradient near the surface of the specimen. The surface temperature evolution is captured by an infrared camera allowing thermal strain evaluation on the surface. A pair of high frequency angle-beam Rayleigh surface wave transducers are used to probe the thermal strain-induced changes in near-surface elastic properties. The slope of the relative change in Rayleigh wave speed with the applied thermal strain is taken as a measure of nonlinearity (γ) evaluated at several locations across the specimen along the intact and cracked regions. Our results show that γ measures higher near the crack and decreases as the probe moves towards the crack tip, demonstrating the potential of thermal-pump DAET for in-situ evaluation of closed fatigue cracks.

친환경 바이오연료를 사용하는 난방시스템 디자인설계 및 환경시험평가

Research and development for alternatives to fossil fuels such as coal and petroleum have progressed considerably worldwide. Among clean fuels, bio-diesel has been a representative fuel and it was used for the following advantages; renewable, ready to use with low fine dust emission and non-toxicity. But it is expensive and cause strain on local resources. In our study, to resolve these issues, we developed two types of heating systems by direct input of waste cooking oil, and the heating system was optimized through mechanical design and design process. In addition, we conducted an environmental test to evaluate the reliability and environmental characteristics of the developed device. Firstly, through the design modification of heat recirculation system, more efficient combustion for the complete combustion of bio-fuel(waste cooking oil), was possible. As for the heating system, two products (tube heating system, agricultural hot air blower) were optimized for management convenience, space utilization, and efficiency improvement by 6-step design. From the environmental test result, the combustion efficiency of the heating system was up to 99%, the average oxygen concentration was 8.3%, and the CO concentration was 7.9 ppm for a stable combustion, NOx was up to 67 ppm, and SOx was not detected.

Rancang Bangun Mesin Pengering Ikan Memanfaatkan Sirkulasi Udara Panas Bagi Nelayan Desa Lekok Pasuruan

The Indonesian region, which has a tropical climate and has a wide sea, is one of the factors that make the population a fisherman. Fishermen from Pasuruan Regency, especially Lekok Village, are one of the producers of high quality marine products so that production reaches foreign exports. This study aims to develop the productivity of marine products in Lekok District, Pasuruan Regency which is constrained by the process of drying fish. Using research methods of literature and empirical studies, an automatic fish drying machine is designed by utilizing a hot air blower which is controlled by a thermistor and accompanied by a rotating system so that the results resemble manual drying using solar radiation. From the results of data analysis and system testing, it shows that the quality of fish that is dried with a rotary system is more effective than drying machines in general, such as the rack type because the results of drying fish are more even. The test results for the drying process require a temperature setting of 45-50 degrees within 220 minutes to reach a moisture content of 0.38% with a drying machine capacity of 32.5 kilograms.

Bluetooth Operated Virus Destroyer Cum Room Heater

Abstract: The idea introduced here is expected to kill any infection drifting in the air by which air will be decontaminated persistently by killing the miniature creatures like microbes, infection, organism, and so on. In such manner, wall mounted sort of rectangular box prepared UV (Ultra Violet) light and hot air blower configuration is very successful at annihilating microbes in two phases. The Bluetooth gadget interacted with principal handling unit will have a remote correspondence interface with our PDA to such an extent that, hot air blower and UV light both can be controlled freely. Delivering hot air is to keep up with additional security to such an extent that the air goes through UV light and hot compressed air firearm, in this manner any kind of infection can be killed actually. The framework is exceptionally helpful for winter season to keep up with the room temperature. With the assistance of a little instrumentation fan organized at the entry of UV chamber, air will be sucked in to the compartment which will be gone through the UV light. To kill the infection successfully, here 1 feet length UV light is utilized and it is stimulated through electronic balance built with PWM IC. At the point when air is pulled in to the gadget, it will go through the little rectangular inward chamber by uncovering UV light. Toward the finish of chamber, hot air will be produced through hot air blower. Hot air blower can be invigorated when required, generally sanitized air will be conveyed through a little vent openings made toward the finish of UV light at base side of the compartment. At the point when the hot air blower is stimulated, it is vital for measure the coursing air temperature and in like manner we should control the hot air blower. To do as such, here hot air blower isn't stimulated consistently, it will be invigorated and de-empowered with a particular timings. Inputted air temperature can be estimated and shown through 7-portion show by which hot air blower can be turned off through cell phone when not needed.

Impulse Response Estimation Using Online Built-In Self-Scaling Method

An extension of the built-in self-scaling (BS) method to online estimation of impulse responses is proposed. It allows estimation to be carried out in real time, which is beneficial for online monitoring, in line with trends in Industry 4.0. The method achieves higher accuracy compared with the standard kernel-based (KB) estimation, and allows the estimate to be available before the end of the identification test. This leads to time savings which are important particularly for the industry. The relationship between the standard KB estimate and that of the BS method is expounded through a rotation matrix, which shows how the dc gain term in the BS technique adjusts the standard KB estimate. Results from a hot air blower experiment illustrate the main concepts introduced.

Thermal and Principal Ablation Properties of Carbon-Fibre-Reinforced Polymers with Out-of-Plane Fibre Orientation

This work characterises thermal properties of a typical epoxy-based carbon-fibre-reinforced polymer used in aircraft construction, but with an out-of-plane fibre orientation, and assesses its potential as a structural ablative material. Samples of the commercially available Hexply® 8552/IM7 are prepared with out-of-plane angles up to 90°, with a focus on 0° to 15°, enhancing thermal conductivity through the thickness of the panel. Ablation processes are simulated by a hot-air blower at 580 °C, and examined in detail by ultrasonic testing and microfocused computed X-ray tomography afterwards. Matrix degradation is characterised by infrared spectroscopy and mass loss. To assess structural properties, tensile, compression, and bending tests are performed. The results show a loss in mechanical performance with an increasing fibre angle, which may be negligible for angles lower than ~5° in the initial state. Composite material with an out-of-plane fibre orientation is deeply penetrated concerning matrix degradation by thermal loading, but it is held together by the fibres fixed in the intact matrix underneath. This type of material shows a high potential for structural components in single-use, high-temperature, ablative applications with a focus on saving weight.

Design consideration of smart solar dryer for precision drying

A sensor based solar dryer was designed to control the drying environment for precision drying of agricultural produce. The system entirely used solar energy utilizing both thermal and electrical effect. Paraffin wax (PCM) was used for storage of thermal energy whereas solar battery was used to store the electrical energy. Hot air blower was also provided to supply heat when there is less or no solar radiation. Temperature sensors were provided to control the environment of drying chamber. The exhaust fan started operating depending on the set temperature and thus control the drying environment. Load cells were provided below each tray to measure the dry weight. The drying chamber was made of mild steel with glass wool insulation. The capacity of the designed dryer was 10-15 kg with 6 trays. The designed dryer has target temperature of 55-60oC.

Antioxidant effects of green tea extracts on lipid oxidation of half-dried eels

In order to explore the change of lipid oxidation of half-dried eels treated with green tea extracts and stored frozen, acid values, peroxide values, carbonyl values, and TBA values were measured. The eels were placed into the plastic bag and soaked for 1 hr in the solution mixed with distilled water and green tea extracts, and also vacuumed and stored frozen at –18 ∼ –20°C for 9 months after being dried with a hot-air blower for 15 hrs at 35°C (Aw 90-91). The control consisted of eels prepared in the same way without any pretreatment. At the end of the 1st month, 3rd month, 6th month, and 9th month, eel oil obtained from the samples were tested for its lipid oxidation. The activity of green tea extracts 1 mL was very similar to Vitamin C 500 μM 0.8 mL. The acid values, peroxide values, carbonyl values, and TBA values of eels treated with green tea extracts were lower than those of the control during 9 months of frozen storage (p<0.05). While the acid values and peroxide values of the control and eels treated with green tea extracts highly increased after the first month of frozen storage, the TBA values increased greatly on the third month of frozen storage. Compared to the control, the pre-application of green tea extracts to half-dried eels meaningfully prevented the generation of TBA compound during the frozen storage (p<0.01). In conclusion, pre-application of green tea extracts was effective in delaying early-stage peracid inducement and preventing the generation of secondary oxidation compounds, such as carbonyl compound and TBA compound, in the course of the drying and frozen storage

TO DETERMINE RELATION OF SYMPTOM DURATION IN OUTCOME OF CTS

Background & Method: The study was conducted at the neurology Department of Amaltas Institute of Medical Sciences, Dewas, M.P. In our laboratory, the hands are evaluated for CTS using standard techniques with Nicolet Viking IV (ver12). The skin temperature of the body part, under evaluation, is measured using a probe connected to the machine and is maintained at 310c using a commercial hot air blower.
 Result: The number of symptomatic hands was more in females (73 vs. 27%) and persons with high BMI (61.5 vs. 38.5); 27.7% of the hands belonged to the persons having concomitant medical issues. Female gender showed slightly higher odds (OR 1.2, CI 0.5-2.6, two-tailed p= 0.5) for remission on medical therapy. The median duration of symptoms of our study population was12 months (mean 24.16 ± 28.93 months). We had 40 patients having CTS in bilateral hands (n= 80 hands), while 50 patients had unilateral hand symptoms (n= 50 hands). Forty-one (31.5%) hands were symptomatic for 10 months or less (median 6 months) while remaining 89 hands were symptomatic for longer than 10 months (median 24 months). Shorter duration of the symptoms, at presentation, had significant higher odds of spontaneous remission (OR 9.47 CI 3.8-23.1, two-tailed p= <0.0001). 
 Conclusion: In conclusion, it seems reasonable to treat subjects of CTS, conservatively for first ten months after symptom onset, more so when they have four or more out of the seven favorable factors.
 Keywords: Symptom, CTS, MMA & SDL.

Moistube irrigation (MTI) discharge under variable evaporative demand.

We investigated the conceptual capability of Moistube irrigation (MTI) to discharge under zero applied positive pressure and under varied climatic conditions by inducing an artificial evaporative demand (Ed) or negative pressure around Moistube tubing. This study was premised on the null hypothesis that an artificially induced Ed or negative pressure does not impact MTI discharge. Moistube tubing was enclosed in a 1 m long PVC conduit. A 20 l water reservoir placed on an electronic balance provided a continuous supply of water whilst a three-speed hot air blower facilitated the radiative factor and advection process. The procedure was conducted under varied climatic conditions with three air velocity (ua) treatments namely; 1.2 m.s-1, 2.5 m.s-1, and 3.0 m.s-1 and the experiment run times were 159 h, 134 h and 10 h, respectively. The average temperature (Tave) and relative humidity (RH) data for ua = 1.2 m.s-1 were 53°C and 7.31%, whilst for ua = 2.5 m.s-1, Tave was 56°C and RH = 7.19%, and for ua = 3.0 m.s-1, Tave was 63°C and RH = 6.16%. The experimental data was input into the four variable Penman-Monteith method to compute the evaporative demand (Ed). For each Ed, the instantaneous mass flow rate ([Formula: see text]) was recorded using an electronic balance and subsequently converted to volumetric flow rates. For each of the air velocities, the respective Ed values obtained were 0.16, 0.31 and 0.36 mm.d-1. The Bowen ratios (r) were well below 1 (r < 1), which suggested a sufficient supply of moisture to evaporate. For Ed = 0.16 mm.d-1 the vapour pressure deficit (VPD) was 113.08 mbars, whilst for Ed = 0.31 mm.d-1 and for Ed = 0.36 mm.d-1 the VPD were 129.93 mbars and 150.14 mbars, respectively. The recorded discharges (q) at normalised time (t*) = 1 h for Ed = 0.16 mm.d-1 was 7.67*10-3 l.hr-1.m-1 length, whilst for Ed = 0.31 mm.d-1 q = 14.5*10-3 l.hr-1.m-1 length, and for Ed = 0.36 mm.d-1 q = 20.8*10-3 l.hr-1.m-1 length. The imposed negative pressure causes an exponential increase in Moistube™ discharge, thus disproving the null hypothesis. The higher the evaporative demand the higher the discharge. This phenomenon allows MTI to be used for deficit irrigation purposes and allows irrigators to capitalize on realistic soil matric potential irrigation scheduling approach.

Experimental Performance Analysis of a Small Thermoelectric System Applicable to Real-Time PCR Devices

At the International Space Station (ISS), not only observation of the space environment, but also biological and medical research under weightlessness has been conducted. The efficient use of energy from waste heat from the ISS away from the Earth is very important to the efficient operation of the ISS. To develop a thermoelectric module that can be used for real-time polymerase chain reaction (PCR) machinery used in biological and medical research, we simulated and evaluated the thermoelectric waste heat recovery system. Specifically, the thermoelectric module was attached to a stainless steel duct, and a hot air blower was faced with the duct inlet. The power of the thermoelectric system was measured by controlling the temperature of the hot air inlet. Additionally, the thermoelectric performance was evaluated according to the heat sink attached to the cold side of the thermoelectric module. Here, we also found the optimal heat exchange factors to improve the power and efficiency of the thermoelectric module. In this regard, it is expected that the thermoelectric module development and analysis study using waste heat will play an important role in the biological and medical research that is being conducted at ISS by developing a real-time PCR utilizing it.

Characteristics of helicopter engine exhaust through scaled experiments using stereoscopic particle image velocimetry

Helicopter engines are often mounted atop the fuselage to keep the aircraft footprint small and optimal for operations. As a result, hot gases produced by the engines may inadvertently impinge upon the tail boom or dissipate inefficiently that compromises on operation safety. In this study, a scaled fuselage model with a hot air blower was used to simulate hot exhaust gases. The velocity field immediately outside the exhaust port was measured through stereoscopic particle image velocimetry to capture the trajectory and flow behaviour of the gases. Two cases were considered: freestream to exhaust velocity ratios of 0 (no freestream velocity) and 0.46 (co-flowing free stream), respectively. The formation of a counter-rotating vortex pair was detected for both cases but were opposite in the rotational sense. For the case without freestream, the plume formed into a small “kidney” shape, before expanding and dissipating downstream. For the case with freestream, the plume formed into a slenderer and more elongated “reversed-C” shape as compared to the case without freestream. It also retained its shape further downstream and maintained its relative position. These observations on the trajectory and shape of plume provide basis to understanding the nature and interaction of the plume with its surroundings.

Experimental Study on a Thermoelectric Generator for Industrial Waste Heat Recovery Based on a Hexagonal Heat Exchanger

To study on the thermoelectric power generation for industrial waste heat recovery applied in a hot-air blower, an experimental thermoelectric generator (TEG) bench with the hexagonal heat exchanger and commercially available Bi2Te3 thermoelectric modules (TEMs) was established, and its performance was analyzed. The influences of several important influencing factors such as heat exchanger material, inlet gas temperature, backpressure, coolant temperature, clamping pressure and external load current on the output power and voltage of the TEG were comparatively tested. Experimental results show that the heat exchanger material, inlet gas temperature, clamping pressure and hot gas backpressure significantly affect the temperature distribution of the hexagonal heat exchanger, the brass hexagonal heat exchanger with lower backpressure and coolant temperature using ice water mixture enhance the temperature difference of TEMs and the overall output performance of TEG. Furthermore, compared with the flat-plate heat exchanger, the designed hexagonal heat exchanger has obvious advantages in temperature uniformity and low backpressure. When the maximum inlet gas temperature is 360 °C, the maximum hot side temperature of TEMs is 269.2 °C, the maximum clamping pressure of TEMs is 360 kg/m2, the generated maximum output power of TEG is approximately 11.5 W and the corresponding system efficiency is close to 1.0%. The meaningful results provide a good guide for the system optimization of low backpressure and temperature-uniform TEG, and especially demonstrate the promising potential of using brass hexagonal heat exchanger in the automotive exhaust heat recovery without degrading the original performance of internal combustion engine.

Kernel-Based Impulse Response Estimation With Prior DC Gain Using Built-In Self-Scaling Technique

A method is proposed for kernel-based impulse response estimation incorporating the prior dc gain by extending the standard Bayesian formulation to the unconstrained least squares framework. It has a key feature of built-in self-scaling (BS) first with respect to the reliability of the measurements and second with respect to the number of measurements. The proposed technique is able to achieve, in general, higher estimation accuracy and lower uncertainty when compared with the standard kernel-based formulation and a method which first estimates the step response and then constructs the impulse response of the system. This BS approach has a further advantage of being computationally efficient, since it does not introduce additional hyperparameters for tuning. An application on a real hot air blower illustrates that the proposed approach is feasible for practical implementation. Trends related to error and uncertainty with respect to data length and noise level are also presented for the first time to analyze the efficacy of the proposed method in comparison with the other methods, thus enhancing the significance of the work to the measurement community.

Microstructural and mechanical properties of Cu-Ni-Mn-Mo austempered ductile iron obtained from two-step hot air austempering

In the present work, mechanical and microstructural properties of Austempered Ductile Iron (ADI) alloyed with Cu-Ni-Mn-Mo submitted to different hot air austempering cycles in a two-step mechanism were evaluated. In the first step, cooling and austempering were performed in an experimental hot air blower device. In the second step, the austempering was performed in a muffle furnace. Bars with Ø16.5 mm and 90 mm of length were austenitized in an electric resistive furnace for 90 min at 860°C. Austempering first step was performed for 10 min at 290°C, 320°C and 350°C corresponding to cycles I, II and III, respectively. Austempering second step was performed for 60 min at 380°C for all cycles. The measurements of Brinell hardness, elongation, yield strength, and ultimate tensile strength for cycle I were 288 HB, 5.0%, 840 MPa, and 988 MPa. For cycle II, the measurements were: 264 HB, 5.9%, 717 MPa, and 876 MPa. And for cycle III: 257 HB, 6.6%, 711 MPa, and 888 MPa. Microstructural analysis indicated the presence of pearlite-free ausferrite.