The Best Working Condition of the Food Refrigeration and Frost Time Determine

The cold storage temperature in China is required at-18°C. At the temperature, microbial breeding is almost completely stopped, biochemical changes are greatly suppressed in the food. However, the evaporator surface will frost easily at the low temperature. Because of the high thermal resistance of frost layer, the heat transfer effect becomes worse. It also led to the decrease of the evaporation temperature, the power consumption of refrigeration unit increases and dry food consumption is huge. Therefore the experiment research of the heat exchanger in a certain air temperature, wind speed, relative humidity condition and the optimum working condition of the food refrigeration has a practical guiding significance to the food refrigeration. Experimental results show that the economic defrosting cycle is set to 2 ~ 3 hours, defrosting time is set to 25 min ~ 40 min.

Experiment Study on the Treatment of Arsenic Drinking Water in Integrated Efficient-Whirling Clarifier

In order to investigate arsenic drinking water treatment effect of enhanced coagulation in integrated efficient-whirling clarifier, and explore optimum working condition, the experiment of arsenic removal was carried out for raw water, the arsenic concentration of 0.1mg/L (100µg/L) and the turbidity of 100NTU. In this experiment, the oxidant’s dosage of sodium hypochlorite (NaClO) was 10mg/L and the coagulant’s dosage of ferric chloride (FeCl3) was 15mg/L, when three kinds of reaction time (T) in the first and second flocculation zone were employed, which respectively equal to 5.4 minutes, 2.7 minutes and 1.8 minutes. The results of experiment showed that the concentration of arsenic all drop below 10µg/L, which reached drinking water sanitary standard (GB 5749-2006), and the best working condition for arsenic removal was reaction time equal to 2.7 minutes.

Research of Treating High Ammonia-N Wastewater by CASS Process

High ammonia-N wastewater is leading to serious environment consequence. Adopting CASS process (Cyclic Activated Sludge System) to treat high ammonia-N wastewater is a good select, which is proved to be a flexible, convenient and efficient treatment. Kinds of factors which effected the nitrogen removal of high ammonia-N wastewater were studied and the optimum working condition of treating high ammonia-N wastewater by CASS process was discussed.

The Application of CAN Bus in Monitoring and Controlling System for Combine Harvester

With ARM processor as upper computer and MCU as lower computers, a monitoring and controlling system for combine harvester is constructed in this paper. CAN bus is used here to realize decentralized control and centralized management. By monitoring and controlling running status of lower computers and relevant parameters through upper computer, the unit can work under an optimum working condition. Therefore, the unit’s work efficiency will be increased, and the fault rate will be reduced. Experiment shows that, upper computer can communicate with lower computers reliably. The expected goal is realized.

Design Optimization of Diffuser Type Valveless Micropumps

Valveless piezoelectric micropumps are in wide practical use due to their ability to conduct particles with absence of interior moving mechanical parts. In this paper, using finite element method, an extended numerical study on fluid flow through micropump chamber and diffuser valves is conducted to find out the optimum working conditions of micropump. In order to obtain maximum generality of the reported results, an analytical study along with a dimensional analysis is presented primarily, to investigate the main dimensionless groups of parameters affecting the micropump net flux. Consequently, the parameters appeared in the main dimensionless groups have been changed in order to understand how the pump rectification efficiency, defining as the ratio of micropump net flux to sum of the absolute values of fluxes of inlet and outlet valves, and optimum diffuser angle depend on these parameters. At last, a set of characteristic curves are constructed which show these dependencies. The optimum working condition of micropump can be clearly found out through the use of these general characteristic curves.