Paint Coating Removal by Heating for High-Strength Bolted Joints in Steel Bridge and Its Influence on Bolt Axial Force

A series of experiments were carried out for developing a paint coating removal method for high-strength bolted joints in steel bridges. The paint-coated bolted joint specimens were heated to the target temperature of 200 °C by using a sheet-type ceramic heater. The maximum temperature of specimens could be controlled within 10% of the target value. The paint coating was easily removed by using general tools after heating. The behaviour of bolts with thermal expansion and shrinkage was monitored by strain gauges attached to the bolts during heating. It was estimated that the axial forces of the bolts were reduced by 2.6% of the initially installed axial forces, on average.

Experimental studies of the thermal regime of the room when using heating ceramic panels

The article presents the results of experimental studies of the parameters of ceramic panels. Experimental measurements of air temperature in a room for which an electric ceramic panel is used as heating devices are given. The automatic system of monitoring of temperature in the room is described. During the experiments it was determined that the surface temperature of the ceramic plate of the heater is higher in the center and decreases when approaching the edges. It is proved that the use of constant surface temperature is acceptable in CFD modeling of a room with ceramic electric heaters. The profile of temperature distribution on height of the room at its heating by means of an electric ceramic heater is resulted in work. The air temperature is relatively evenly distributed over the height of the room. In this study, when entering the quasi-stationary mode, the air temperature in the height of the room varied in the range from 24 to 27˚C, which is slightly higher than the norm for the temperature in domestic premises. In order to save energy in this case it is necessary to reduce the service life of ceramic electric heaters. In the future it is necessary to develop a thermophysical numerical model and verify it with the help of the obtained experimental data. In addition, with the help of the model you can conduct research and determine the optimal location of ceramic electric heaters in the space of the room. Key words: radiation ceramic heater, experimental research, temperature monitoring.

Estimasi Laju Aliran Sirkulasi Alam Berdasarkan Beda Temperatur pada Untai FASSIP-01

Penguasaan terhadap kapasitas pendinginansystem pendinging pasif dilakukan melalui penelitian di laboratorium Termohidrolika PTKRNBATAN. Untai FASSIP-01 telah dikonstruksi untuk studi fenomena sirkulasi alam. Tujuanpenelitian adalah untuk mengestimasi laju aliran sirkulasi alam berdasarkan beda temperatur dibagian heater (BCH, blanket ceramic heater) dan di bagian cooler atau WCT (water coolingtank). Metode penelitian dilakukan dengan menentukan perubahan di WCT untuk variasitemperature 10℃, 20℃, 30℃, 40℃ dan 50℃, serta perubahan temperature di BCH yaitu60℃, 70℃, 80℃, 90℃ dan 100℃. Parameter geometri Untai FASSIP-01 seperti tinggi untai600 cm, lebar untai 350 cm dan diameter pipa sebesar 2,56 cm dimasukkan dalam perhitungan.Hasil perhitungan menunjukkan bahwa semakin besar perbedaan temperatur anatara BCH danWTC, maka akan semakin besar pula laju aliran air pada untai FASSIP-01. Ketika perbedaantemperatur BCH dan WTC 10˚C, laju aliran bernilai paling kecil yaitu 0,2903 m/s, sedangkanketika perbedaan temperatur BCH dan WTC 90˚C, laju aliran bernilai paling besar yaitu 1,0456m/s. Kata Kunci : laju aliran, sirkulasi alami, BCH dan WCT, temperatur, untai FASSIP-01

KARAKTERISASI LAJU ALIRAN MASSA PADA PIPA BAGIAN HEATER BERDASARKAN PERUBAHAN DAYA DI UNTAI (FASSIP-01) MOD.1

<p>Kecelakaan reaktor nuklir di Fukushima Daiichi Jepang pada 11 Maret 2011, menyebabkan dilakukannya penelitian ini di berbagai negara termasuk Indonesia yang sedang mengembangkan sistem keselamatan pasif dengan alat Untai FASSIP-01 Mod.1 di PTKRN-BATAN Serpong. Ada beberapa komponen pada Untai FASSIP-01 Mod.1 yaitu komponen pemanas yang dinamakan <em>Blanke</em><em>t </em><em>Ceramic Heater</em> (BCH-02), komponen pendingin dengan sistem <em>refrig</em><em>e</em><em>rant </em><em>cooling system</em> (RCS), dan tabung ekspansi. Sistem pasif menerapkan hukum alami untuk mengamati kondisi yang tidak stabil pada reaktor. Perlu dilakukannya eksperimen untuk mengetahui karakterisasi distribusi temperatur pada pemanas BCH-02 di Untai FASSIP-01 Mod.1 dengan memvariasikan daya dan tegangan 20 volt – 160 volt. Pengujian dilakukan selama 120 menit dan tegangan dinaikkan sebesar 20 volt selama 15 menit, eksperimen pada BCH-02 dilakukan dengan posisi vertikal dan horizontal. Hasil eksperimen pada BCH-02, semakin besar daya yang diberikan maka temperaturnya semakin tinggi. Temperatur yang berada di permukaan <em>ceramic-brick</em> lebih tinggi dibandingkan dengan temperatur di dalam pipa <em>section</em>, hal ini disebabkan karena terjadi <em>heat </em><em>loss</em> pada celah celah ruang di dalam BCH-02 sebelum mencapai pipa <em>section</em>.</p>

Study of PET Spectral Absorbance in Designing Infrared Heating Control of Vacuum Forming Machine

Heating process is the first step in vacuum forming that transforms the plastic sheet from its glassy state to rubbery state, pliable enough to be formed to mold’s shape. Infrared ceramic heaters with zoning control are commonly used in thermoforming industry, in which temperature distribution and its consistency throughout processing time become very important in determining the thickness and properties of manufactured parts. Compared to other thermoplastics, Polyethylene Terephthalate (PET) with its crystallization characteristics is known to have narrower process window. Slight uneven temperature distribution and overheating will degrade PET as well as cause visible defects in final product. In order to obtain proper parameter setting of infrared ceramic heater in PET vacuum forming, a numerical approach that considers PET spectral absorbance was deployed and two methods to control temperature were compared. The experiment resulted in a reliable temperature distribution by means of voltage potentiometer control for pre-heating and implanted thermocouple inside ceramic emitter for main heating in PET vacuum forming machine.