A parallel plate type ESP used for indoor air cleaning to remove particles. The ESP is handling 100 m3/h of gas. The spacing between two plates is 10 cm and the plates are 1 m high and 1 m long. Assume the particles are pre-charged in an electric field strength of 100 kV/m and under ion concentration of 5x1013/m3 for 2 second before entering the ESP plates. To evaluate the minimum efficiency of the ESP, its efficiency for the particle having highest penetration (or lowest electrical mobility) is considered. Assume this particle size is 100 nm, and ε=5. What is the maximum charge can the 100 nm particle acquired in pre-charging zone?

An experiment to measure the thermal conductivity of food formulations was carried out by measuring the surface temperature of the food formulations which were formed into flat plates with a thickness of 10 mm. It is found that at steady-state conditions, there is a temperature difference of 40 ° C between the two surfaces, the heat transfer rate per unit area of 4700 W / m2 is measured near the center of the two surfaces. Calculate: the thermal conductivity of the product, = AnswerW / m ° C

A composite wall consisting of five series layers of materials with different properties. Layer thickness, thermal conductivity of the layers and temperatures are shown on the figure. Based on Fourier's law for conduction, answer the following questions. 1. What are the main assumptions? 2. Drive an equation to calculate the heat transfer rate through the Composite wall? 3. Draw the thermal circuit through composite wall? 4. What are the value Ti? 5. What are the value Tj? 6. What are the value Tr? Givens: KA = 2 W/m. °C KB = 1 W/m.°C Kc= 5 W/m. °C Kp= 4 W/m. °C 100°C Ti 25°C Tj Tr А C D +2cm + 6 cm- -4 cm 4cm