No abstract

Hava fanları endüstride kullanılan gaz fazındaki akışkana yön veren, havayı bir yerden belli bir hacimde alıp başka bir yere ileten ekipmanlardır. Prosesteki rolü, akışkan yataklı kurutucuda akış oluşturarak zorlanmış taşınım ile ısı transferi prosesi ile ürünün hızla kurumasını sağlamaktır. Hava fanı, bu proses için birinci derecede önemli bir ekipmandır. Bu ekipmanda gerçekleşebilecek bir arıza, üretimin durmasına ve ürün kalitesi konusunda problemler yaşanmasına neden olmaktadır. Titreşim ölçüm cihazıyla ve diğer ekipmanlar ile yapılan ölçümlerde, titreşim frekanslarının ve şiddetinin değerlendirilmesi neticesinde makinada meydana gelmiş veya gelebilecek arızalar belirlenmektedir. Bunun sonucu olarak, döner ekipmanlarda (fan, pompa, kompresör vb.) meydana gelen hasarların erken teşhisi durum izleme odaklı bakım programlarının en önemli görevlerinden bir tanesidir. Her döner ekipmanda, farklı birçok arıza (rulman ve dişli arızası, balans arızası vb.) meydana gelebilir. Bu arızalardan yapısal esneklik durumu da makine arızası olarak karşımıza çıkmaktadır. Ancak yapısal esneklik arızası, ekipman üzerine tek noktadan sabitlenmiş sensor titreşim trendi izleme yöntemleri ile tespit edilmesi oldukça zordur. Yapısal esneklik arızasının titreşim analizi ile tespiti için yataklardan 3 eksenden de ölçüm alınarak hız spektrumu, ivme spektrumu ve zarf spektrumu grafikleri incelenmeli ve izin verilen değer aralıklarında olması sağlanmalıdır. Zaman dalga formu grafikleri ile analizleri yapısal esneklik arızası karşısında beklenen cevabı vermemektedir. Bu çalışmada, bir maden tesisinde bulunan hava fanında meydana gelmiş yapısal esneklik arızasının kestirimci bakım aracı titreşim analizörü ölçümleri sayesinde spektrum analizi ile erken teşhisi ele alınmıştır. Esnekliğin hangi kısımdan ve hangi yatak bölgesinde olduğunun belirlenmesi için gerçekleştirilen spektrum analizi detayları ile açıklanmıştır. Arıza giderilerek sistem uygun çalışma koşulları yeniden sağlanmıştır.

There are innumerable events related to heat transfer that we experience or see in our daily lives. In this study, research and experimental calculations were made about multilayer plane walls, which are often made of different materials. There are so much application areas on heat transfer. In order to better understand heat conduction, we need to make an explanation of the thermal properties and heat transfer type of the materials used in the experiment. It is known that heat transfer occurs in three different ways (conduction, convection, radiation). In this study, a layered wall heat conduction mechanism was established by combining 6 different materials (Copper, St37 Steel, AISI 1050 Aluminum, Wood, Rock wool, Glass wool) with different pediments of 30*30 cm. Heat is produced by gradually applying voltage from the copper plate and the temperature between each plate is measured by temperature sensors with Arduino programming. In the Arduino assembly, one Arduino Unocard, 5 lm35 temperature sensors and 1 20*4 I2C LCD screen are used to take the measurement outputs. The LM35 temperature sensor produces a voltage between zero and 5 V from the analog output, and the temperature measurement is made by producing a value of 10mV for each degree Celsius. The right leg of lm35s with three legs is connected to GND on the breadboard for grounding, the middle leg is connected to the analog output on the uno board, the left leg is connected to the 5V input on the breadboard and 5 lm35s are connected in parallel on the breadboard. The sensors were placed in the middle of the plates and the measurements were printed and recorded on the LCD screen. The measurements in the experimental setup were analyzed by applying a stepped voltage of the same value to the layered wall designed from the same materials in the SolidWorks thermal program, the data were collected and compared with the theoretical calculations of heat transfer.

Most world country dependent on foreign oil to make things working, which means political disputes or any disputes between countries can result in energy crunches. The negative changes that occur in the global climate and environment due to the burning of fossil fuels, stimulate the search for modern and environmentally friendly sources of energy production. In addition, continued concern about the storage and processing of nuclear waste may limit nuclear energy options. New concepts use nanotechnology as a new application for production of the electricity. In the modern thin-film application technologies, a number of layers can be deposited to improve the cells' energy density, reduce operating temperatures, and lower manufacturing costs. Solid oxide fuel cells (SOFCs), which have the ability to convert chemical energy into electrical energy without combustion, are among the advantages of this cell; High efficiency and much less pollution. Fuel cells -zinc, air, proton exchange membranes, and solid oxide are recent and established energy applications. Several of these solid oxide fuel cells (SOFCs) have emerged as fuel cell technology that has additional positive advantages.

Drinking water and utility water are indispensable elements in meeting many vital needs, especially drinking, cooking and cleaning. Unconscious agricultural irrigation, pollution, and population growth cause water scarcity that humanity must cope with. As a result of global warming and climate change, especially the amount of potable water is decreasing, making it difficult to access clean water resources. The occupancy of drinking water sources decreases in high temperature seasons and some of them even disappear. This situation has made it necessary to search for alternative methods to obtain drinking water. One of these methods is to obtain potable water from atmospheric air containing high amounts of water. With the widespread use of this method, the scarcity of drinking water can be alleviated to a certain extent. In this study, the processes of condensing the water in the atmospheric air by using solar energy, which is a renewable energy source, and thus obtaining potable water are discussed. Efforts to increase the efficiency of obtaining potable water by using various absorbents and by various systemic solar still designs have yielded positive results. As a result of this literature review, the limits of the studies and their regional effectiveness were evaluated together. The effect of temperature, velocity, humidity of the atmospheric air and the amount of solar radiation on the process were evaluated. It has been concluded that certain desiccant materials with good water absorbers such as calcium chloride and silica gel can be used effectively in the processes of obtaining potable water from atmospheric air by developing correct designs. It has been demonstrated that high atmospheric air temperature, which is an important cause of water scarcity, can be converted from disadvantage to advantage by utilizing solar energy.