Effect of Adsorbent Diameter on the Performance of Adsorption Refrigeration

Adsorbents are important components in adsorption refrigeration. The diameter of an adsorbent can af-fect the heat and mass transfer of an adsorber. The effect of particle diameter on effective thermal conductivity was investigated. The heat transfer coefficient of the refrigerant and the void rate of the adsorbent layer can also affect the effective thermal conductivity of adsorbents. The performance of mass transfer in the adsorber is better when pressure drop decreases. Pressure drop decreases with increasing permeability. The permeability of the adsorbent layer can be improved with increasing adsorbent diameter. The effect of adsorbent diameter on refrigeration output power was experimentally studied. Output power initially increases and then decreases with increasing diameter under different cycle time conditions. Output power increases with decreasing cycle time under similar diameters.     

黄铜矿低温氯化-选择性氧化提取铜过程

对流化床中黄铜矿精矿低温氯化和选择性氧化提取铜过程进行了研究. 采用二段氯化,使下段排气中残氯和产物S2Cl2在上段中消耗于精矿的氯化,温度分别控制在270和250℃左右,且下段排气残氯浓度不超过0.015%,得到充分氯化的低硫产物. 增设一个反应器,仅用氮气对氯化产物热处理,其硫含量进一步降低. 低硫氯化产物在350~360℃能平稳进行氧化反应,放出的Cl2在上部反应器中用于精矿的氯化而脱除. 稀盐酸对氧化产物浸取有效,pH值在0.30~1.86范围,Cu接近全溶,Fe浸出率不超过5%. 浸出液中Cu, Fe和SO42-浓度随固液比提高呈线性增加,固液比为0.5 g/mL时,Cu浓度超过115 g/L,而Fe/Cu含量比低于0.03,SO42-浓度也很低,满足铜电积操作要求. 同时研究了精矿所含微量贵金属和少量杂质随处理过程的变化.     

Optical and NMR Studies on Interdiffusion of Silver in SiO2-B2O3-AI2O3-R2O Glasses

Interdiffusion of silver ions in SiO₂-B₂O₃-AI₂O₃-R₂O glasses where R=Na or K was investigated, using optical transmission, ESR, and wet chemical methods to determine concentration and the chemical state of silver, and NMR spectra as a probe of the glass structure. The concentration of silver introduced by ion exchange increased monotonically, as the line widths of²⁷AI NMR spectra decreased. The sharp and narrow features of ²⁷Al line shapes were broadened and the amount of colloidal silver produced by ion exchange decreased, as R₂O/B₂O₃ approached unity with fixed AI₂O₃. The BO₄ to BO₃ ratio approached unity and the quadrupole coupling constant of BO₃ units varied from 2.70 to 2.96 MH_Z, as R₂O/AI₂O₃, approached unity for fixed B₂O₃. These diverse data suggest a relation between silver diffusion and glass structure, although the phenomena of phase separation and the mixed-alkali effect could also influence silver-colloid formation in the glasses studied.     

ESTIMATION OF DAILY INTAKE OF CHLOROFORM BY JAPANESE HOUSEWIVES

Duplicate portions of daily meals consumed by 21 housewives were collected for 3 consecutive days at Nagoya-city and Asuke-cho in Japan. The 24 h duplicate meals were analyzed for chloroform. Thirty grams of samples, 170 mL of water, 1 mL of phosphoric acid, and 0.5 g of ascorbic acid were mixed in a distillation flask which was heated under nitrogen gas flow. The purged chloroform was trapped in n-pentane cooled at 0° C. The pentane solution was analyzed to by electron capture gas chromatography. Confirmation of chloroform was carried out by GC-MS.
The concentration of chloroform in each of the 24-h duplicate meals were in the range of 1.7 to 45.8 ppb and the average concentration was 13.7± 9.6 ppb.
Daily dietary intake of chloroform by housewives were in the range of 7.5 to 51.9 μg and the mean intake was 26.4 ± 11.8 μg.     

Emulsifying and Bactericidal Properties of a Protamine-Galactomannan Conjugate Prepared by Dry Heating

Protamine was conjugated with galactomannan (GM) in a controlled dry state at 60° and 79% relative humidity. The covalent attachment of GM to protamine was confirmed by SDS-PAGE and gel chromatography. The resulting protamine-GM conjugate had excellent emulsifying properties without significant loss in bactericidal activity. The emulsifying activity was six times and the emulsion stability of the conjugate more than 10 times higher than those of protamine. In acidic (pH 3) and salt (0.2M NaCl) systems the conjugate showed much more effective emulsifying properties than commercial emuJsifiers. In addition, the emulsifying properties of the conjugate were retained after preheating at 90°. Protamine-GM conjugate could be used for processed foods as a bifunctional food additive, emulsifier and antibacterial reagent.