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801.
Currently, China's timber industry is in high demand with the development of real estate. However, there is a certain fire hazard in the production process of wood manufacturing. Once a fire occurs, the fire is violent and the spread is rapid. Therefore, to improve the safety of its production process, ammonium dihydrogen phosphate and magnesium hydroxide were selected to prepare a new composite superfine dry powder, which was denoted as the NH4H2PO4/Mg(OH)2 composite. Furthermore, to figure out dry powders' extinction effect on Class A fire, the wood-crib fire suppression effect of the NH4H2PO4/Mg(OH)2 composite was test, and then compared with that of ultrafine dry powder (UDP) and commercial ABC dry powder (C-ABC) in a 1 m³ chamber. Three parameters of the fire extinguishing process, namely flame extinction time, powder consumption and temperature drop were adopted to measure the fire suppression performance. The results demonstrated that UDP and C-ABC both had a larger flame extinction time and powder consumption than the NH4H2PO4/Mg(OH)2 composite. Besides, a fire (wood cribs) can be extinguished by the NH4H2PO4/Mg(OH)2 composite with the fastest temperature drop and a much-improved toxic gas suppression ability. In short, the NH4H2PO4/Mg(OH)2 composite can better guarantee the safety of the wood processing production process. Moreover, the reasons for performance advantages of the NH4H2PO4/Mg(OH)2 composite were discussed. 相似文献
802.
The minimum ignition temperature of dust suspension (MIT) and the hot surface ignition temperature of the dust layer (LIT) are essential safety parameters for the process industry. However, the knowledge of the ignition behavior when solid mixtures of flammable fuels and phosphorous-free inhibitors are considered is still scarce and further experimental and theoretical analyses are requested. In this work, the ignition temperature of phosphorous-free inhibitors (coal fly ash and calcium carbonate) mixed with lycopodium dust have been studied in terms of LIT analysis (hot plate thickness: 5 mm, 12.5 mm and 15 mm), and by the Godbert-Greenwald test for the MIT. Both coal fly ash and calcium carbonate have been tested at different concentrations and particle sizes.Results show that the effects of the inhibitor can be counter-productive when layer ignition temperature is considered even if the minimum ignition temperature of the dust suspension shows a positive effect from the safety point of view. This behavior has been analyzed in the terms of thermal conductivity and diffusivity of the mixture, by using Maxwell's equation for two-phase solid mixtures. Standard empirical correlations for the ignition temperature of solid mixtures have been also tested, showing their weakness in reproducing mixture behavior. 相似文献
803.
ABSTRACTAn efficient coal de-capacity quota allocation scheme is key for accelerating China’s coal supply-side structure reform. This paper allocates the coal de-capacity quota from the perspective of efficiency to seek the optimal capacity allocation in each Chinese province. First, we estimate the coal capacity of 24 coal-producing provinces based on boundary production function model. According to the actual coal overcapacity in each province, we initially allocate the coal de-capacity quota of reducing 0.8 billion tons among them. Then, we optimize the initial allocation plan by using the zero-sum gains data envelopment model (ZSG-DEA) considering backward coal capacity, coal economic output, and coal resource endowment of each province. The results indicate that: First, there is coal overcapacity all over China, and there are obvious differences among the provinces. Second, the optimal allocation results show that the large coal producing provinces, including Shanxi, Inter Mongolia, Shaanxi, etc., need to undertake most of the coal de-capacity tasks, while the old coal producing provinces in northeast and west China should undertake a heavier burden of coal de-capacity. Third, the “one-size fits-all” approach burdens the small coal producing provinces with reducing coal capacity, leading to a general low enthusiasm for coal de-capacity in these regions. 相似文献
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807.
不同粒径高浓度粉末活性炭组合UF膜工艺特征和过滤效果 总被引:1,自引:0,他引:1
采用一体式高浓度粉末活性炭-超滤(HCPAC-UF)组合工艺,处理高氨氮微污染水源水。选取3种不同粒径(50、3和0.2 μm)的粉末活性炭考察PAC粒径变化对组合工艺处理效果的影响。结果表明,PAC粒径改变分别对UV254表征的腐殖质类有机物和DOC表征的溶解性有机物的去除影响较小;PAC粒径显著影响系统中的微生物的生长环境,PAC粒径越小,系统中微生物的生长受抑制越明显,同时,PAC的粒径越小对减缓HCPAC-UF工艺的膜污染越显著。研究结果对于优化HCPAC-UF工艺参数具有一定参考价值。 相似文献
808.
以阴离子型聚丙烯酰胺(HPAM)为絮凝剂,采用强化混凝的处理方法,对微污染水中有机氯农药(OCPs)的消除进行了研究。考察了HAPM投加量、pH值、原水浊度、粉末活性炭及改性凹凸棒土助凝剂等因素对OCPs消除效果的影响。结果表明,HPAM投加量为0.05~0.1 mg/L时,OCPs不同异构体的去除率可达57.00%~74.56%;浊度去除率与OCPs去除率之间显著相关(p<0.05),较高的原水浊度有利于HPAM对OCPs的去除;HPAM混凝消除OCPs的最佳pH值为5~6;改性凹凸棒土作为助凝剂复配HPAM可有效提高OCPs的去除率,粉末活性炭复配效果不明显,所以凹凸棒土比粉末活性炭更加适合作为助凝剂在强化混凝中去除OCPs。 相似文献
809.
碱性化学镀镍废液的净化处理 总被引:5,自引:0,他引:5
找到了一种处理碱性化学镀镍废液的新方法 ,研究了镀液组成、温度、时间、漂白粉浓度对化学镀镍废液处理结果的影响。结果表明 ,用漂白粉处理碱性化学镀镍废液是可行的。 相似文献
810.
离子交换技术具有交换容量高、能耗低、可再生效率高、操作过程简单、环境友好,并且能同时实现水质净化和资源原位回收等优势,在水处理领域应用十分广泛。在文献及工程调研的基础上,综述了3种典型离子交换剂:沸石、粉末树脂、磁性离子交换树脂的技术原理及其在污水处理中的应用现状;分析了三者在低浓度氨氮回收过程中存在的问题,并提出了相应的研究策略;评价了3种离子交换剂在工程化应用中的经济性,主要介绍了成熟的磁性离子交换树脂工艺;通过分析可知,将离子交换技术从污水治理领域应用到污水中低浓度氨氮原位富集回收领域,对污水全面资源化利用具有重要意义。 相似文献