What is critical needed in compression molding?5 answersCritical aspects needed in compression molding include precise control of process parameters like closing velocity, densification pressure, curing time, and clamp control. Additionally, the use of a reciprocating screw plasticator can help in maintaining thermoplastic material in a plasticated state consistently, reducing variations. The design of the compression molding mold is crucial, especially for processing plastics with poor thermal plastic mobility, as it ensures uniform stress distribution and proper molding of the material. Furthermore, the capacity of the compression press is essential, with larger machines being capable of handling more extensive and automated production runs, up to 5000 tons, while a minimum of 250 tons is needed for processing a reasonable range of products. These elements collectively contribute to the efficiency and quality of the compression molding process.
What is the difference of pressurized gas tank to compression tank?4 answersA pressurized gas tank typically maintains pressure using a secondary fluid or a flexible bladder to exert pressure on the primary fluid. On the other hand, a compression tank, like a heatable compression type high-pressure gas tank, utilizes a flexible sealing part that allows the tank body to change capacity by sliding, effectively reducing the tank's volume to increase internal pressure. Additionally, a pressurized tank for conveying powder features check valves and an elastic body to prevent air flow back from the piping, ensuring controlled powder feeding. These differences highlight how pressurized gas tanks focus on maintaining pressure through secondary fluids, while compression tanks adjust capacity to enhance pressure and functionality.
What are the factors that affect the performance of gas turbines?4 answersThe performance of gas turbines is affected by several factors. These include ambient air temperature, compressor pressure ratio, turbine inlet temperature, compressor efficiency, compressor exit diffuser Cp, combustor pressure loss, turbine efficiency, OTDF, RTDF, blade metal allowable temperature, and turbine exit diffuser Cp. The ambient air temperature has a significant impact on power output and heat rate, with a decrease in air temperature resulting in increased power output and decreased heat rate. Inlet air cooling systems, such as eva-cooler, fog-spray, and mechanical chiller, can be used to enhance power output and lower the heat rate of gas turbines. Monitoring techniques can also help mitigate the effects of operational parameters and environmental variables on gas turbine performance, reducing maintenance costs and improving efficiency. Additionally, factors such as water temperature and the ratio between water and air mass flows can affect the equilibrium conditions of evaporative cooling systems used in thermoelectric plants.
What is compressor?4 answersA compressor is a device used to compress gases or air. It is used in various applications such as refrigeration, air conditioning, and industrial processes. Compressors can be classified into different types based on their operating principles, such as rotary, reciprocating, and centrifugal compressors. They work by increasing the pressure of the gas or air, which results in a decrease in volume. This compressed gas or air can then be used for various purposes. Compressors can be operated using different methods, including using oil separators for cooling and dewatering the compressed air, using a pump and a membrane to periodically compress the working gas, utilizing vibration and movement force for power, and using a compression mechanism and a motor. Compressors can also have specific features, such as grooves for improved compression.
What is the potential of a Tesla turbine to substitute the expansion valve of refrigeration compression cycles?5 answersA Tesla turbine has the potential to substitute the expansion valve in refrigeration compression cycles. The use of a Tesla turbine in these cycles can lead to higher energy efficiency and reduced wasted energy. The turbine can be integrated into the cycle to replace the traditional expansion valve, resulting in improved performance. Studies have shown that the coefficient of performance of the heat pump cycle can be up to 16.3% higher when a Tesla turbine is used instead of the expansion valve. Additionally, practical design rules have been proposed to optimize Tesla turbines for specific operating conditions, including power output, disc sizes, and angular velocity. Miniaturized Tesla turbines have also been shown to exhibit better aerodynamic performance and have potential in the field of microturbomachinery. However, it is important to remove liquid droplets before the flow enters the rotor to minimize back pressure and maintain turbine performance. Experimental investigations have shown that the performance of a Tesla turbine can be enhanced by approximately 38% when used in a unidirectional outlet configuration.
What is the formula in compression test?3 answersThe formula used in compression testing varies depending on the specific context. In one paper, the formula for calculating compression strength is given as Ss = 2.8 p/pid, where Ss represents the compression strength, p is the compression load, and d is the particle size of the sample. Another paper mentions a formula for determining the compression static modulus of elasticity, which involves calculating the difference in stress (Δσs) multiplied by the difference in length (L1 - L2) and dividing it by the difference in displacement (ΔL1 - ΔL2). It is important to note that these formulas are specific to the respective studies and may not be applicable in all compression testing scenarios.