FUNCTIONALITY OF THE CHEMICAL HORIZONTAL TANK APPARATUS WITH A JACKET

Static calculations of the working pressure effects on the chemical horizontal tank apparatus with a jacket were carried out.

Evaluate the Performance of Vertical and Horizontal Liquefied Natural Gas Storage Tanks by Using a Non-Equilibrium Resistance-Capacitance Model

Methane is the primary component of liquefied natural gas (LNG) and a potent greenhouse gas (GHG). The undesired methane emissions across the natural gas supply chain has been proven to worsen the lifecycle GHG emissions from the transportation sector compared with diesel. Therefore, having accurate fast-response models to predict the performance of natural gas infrastructure, such as LNG storage facilities, becomes crucial to minimize methane emissions. In this study, a novel non-equilibrium multi-species thermodynamic model based on the resistance-capacitance network is developed to assess the thermal performance of LNG storage tanks. The accuracy of the non-equilibrium model is validated against the experimental data of a storage tank under dynamic hot gas injection. Then, the model is employed to analyze the performance of two identical vertical and horizontal storage tanks in a refueling station under self-pressurization condition. The results show that the pressure rise in the stationary vertical and horizontal tanks is similar. However, the temperature gradient between the vapor phase and LNG in the horizontal tank is less than that in the vertical tank due to the larger vapor-liquid interface. This feature allows the horizontal tank to reduce the tank pressure faster than the vertical tank under sudden pressure increase.

Pilot Testing of the Waste Metalworking Fluids Biosorption Treatment

Metalworking fluids are liquid wastes of the machines cutting, cooling, and lubrication operations coming in the form of emulsified oil. Waste metalworking fluids in the emulsified form are liberated into the environment through machining wastewater which becomes contaminated with microorganisms and results in a drastic problem of water pollution. To reduce its polluting biosorption the method of treating waste metalworking fluids was employed. An investigation into the anaerobic biological wastewater treatment was conducted for 50 days with the initial sludge dose 2.8 g/l in a horizontal tank with a drum-type mixing device. The results of this study indicate that the existing industrial-activated sludge plant could be used to treat waste MWFs under anaerobic conditions after the additional treatment by fermentation at a temperature of 32-37 оС with nutritional elements input at certain days. The efficiency of biosorption treatment using the granular diatomite as an adsorbent is insignificantly inferior to the system with granular activated carbon SKT-3. So it would be more reasonable to use the diatomite in industrial plants because it is significantly cheaper than the granular activated carbon and there are large quantities available. The COD reduction was significant but to achieve optimum performance further investigation is needed.

Oscillation of Mixing Jets in a Long Horizontal Tank

In contrast to mixing in vertical tanks, jet mixing in long horizontal tanks is scarcely investigated in the literature. It is known that jet mixing in long horizontal tanks is more difficult when compared to short tanks, as more liquid volume must be recirculated through the jets. In this study, computational fluid dynamics (CFD) simulations are conducted for the flow in a horizontal cylindrical tank with a length-to-diameter ratio of 3:1 and a nominal volume of 112,560 L (liquid volume of 75,708 L, i.e. 20,000 gallons). A pair of back-to-back Coldrey nozzles is placed near the center of the tank bottom, and each nozzle directs its jet towards the corresponding vessel end. An intriguing phenomenon is observed in the transient simulations, where the turbulent jets oscillate in both horizontal and vertical directions with a low frequency. In order to determine the source of such oscillation, a number of simulations are conducted to explore the effects of mesh type and size, boundary condition on the free surface, turbulence model, and time step. Oscillation persists in all cases, indicating that it is unlikely the result of some numerical instability. The oscillation also appears to be insensitive to the Reynolds number or symmetry in the nozzle or tank geometry. Another simulation with a single jet also shows the oscillatory flow behavior, and thus the oscillation is more likely to be caused by interaction between the jet and the recirculating flow in the tank, rather than interaction between the two jets. Further analysis of the jet velocity profile suggests that the secondary flow on the cross section of the jets might also contribute to the oscillation. While similar confined jet oscillations due to Coanda effect and blind cavity effect have been previously observed in small cavities by both 2D numerical simulations and laboratory scale experiments, this study shows that such oscillation also exists in industrial scale horizontal tanks. The oscillatory motion of the liquid may lead to improved mixing in the tank.

Finite Element Analysis and Experimental Research for Horizontal Tank to Internal Magnetic Flux Leakage Detection

In view of the petroleum and petrochemical characteristics of horizontal tank, ANSYS software of finite element analysis was carried out on the horizontal tank within the magnetic flux leakage testing, analyzes the influencing factors of defect magnetic flux leakage signals. Experiments verify the finite element analysis results, the experimental results show that the research of horizontal tank within the magnetic flux leakage detection effect is obvious.