The paper presents the results of investigations of transformation plasticity of hot-die steel (high temperature–resistant steel used in high-temperature deforming) during hardening. A special device was used to evaluate transformation plasticity and determine the maximum normal bending stress, modulus of transformation plasticity for medium alloyed and medium carbon steel. 相似文献
Ozone treatment for preventing the biofouling in cooling water systems is investigated.
In the fresh water system, the separating effect of the ozonated water on the microorganisms such as the sphaerotilus and the zoogloea which adhere to the piping and form the slime is recognized. When the ozonated water is supplied intermittently to the piping without stopping the flow of the cooling water, a constant volume of cooling water can be maintained. At the velocity of 1 m/sec, the amount of metal corrosion produced by the ozonated water is reduced on the mild steel, increased on the copper and does not change on the cast iron, when compared with that produced by the water containing no ozone.
In the seawater system, since many substances are oxidized by the ozone, the same treatment as that in the fresh water system cannot be applied. However, if the seawater in the cooling system can be replaced with ozone-containing air intermittently once a week, the adhesion of organisms such as barnacles and mussels to the piping can be prevented without having a bad influence on the other living oceanic organisms. 相似文献
The evolution of an air core is an important phenomenon in hydrocyclones, which are sensitive to the operating conditions. The morphology of the air core in a hydrocyclone is studied experimentally, using a high-speed video camera and a noise analyzer. Three stages are observed during the increase of flow rate from 300 to 2,400 L per hour, which could be separated by both the noise measurement and the stability of the air core. The flow rate is found to have a nonmonotonic effect on the diameter of the air core, leading to a peak diameter. The influence of the overflow and underflow on the underflow-to-throughput ratio and air flow patterns is also investigated. It is found that the underflow-to-throughput ratio and air flow patterns are sensitive to the valve openings of both outlets. 相似文献
Understanding the effect of drying process parameters on food quality is helpful in process optimization and control. The objective of this work is to understand the effect of mild and harsh effective moisture diffusivity (Deff), varied by air temperature and velocity, of drying processes on the physical and sensory quality of flat food products. Pumpkin seeds were selected as a food representative. It was found that increments of air temperature and velocity resulted in increased Deff and brown color on seed hull surfaces and embryos, but decreased hardness of seed embryos. Changes in taste and aroma of seed embryos were able to be sensed. Indicating that Deff is related to seed physical quality. Similar phenomena occurred with both tray and fluidized bed drying. Air temperature, velocity, and Deff should be controlled to ensure the best dried flat food products. Mild drying conditions are potentially preferred for good physical and sensory quality. 相似文献
The formation of potentially carcinogenic organic halides has been shown to result from drinking water disinfection with chlorine. xidative treatment of organic halide precursors with ozone prior to chlorination has surfaced as an attractive technique for reducing the formation of these compounds. In addition to reduction of precursor levels, preozonation has been reported to effect other beneficial results in water treatment. This paper presents design methodologies to optimize the implementation of the ozonation process for water treatment applications. Pre-design considerations common to all ozonation design processes are discussed. Subsequently, design procedures for the ozone generation and contacting systems are reviewed. 相似文献