平流沉砂池设计参数

平流沉砂池设计参数 平流式沉砂池设计参数的研究 邵林广 王华 提要 分析 定性数据统计分析pdf销售业绩分析模板建筑结构震害分析销售进度分析表京东商城竞争战略分析 了国内一些城市污水厂平流式沉砂池处理效果差的原因，研究了排水体制、 初沉池的设置以及除砂设备的选型对平流式沉砂池设计参数的影响，提出了可供选择的设计 方法。 关键词 平流式沉砂池 排水体制 初沉池 除砂设备 设计参数 On Design Parameters of Horizontal Grit Chamber Shao Linguang et al(21) Abstract: The reasons that caused poor performance of horizontal grit chambers (HGC) in the urban wastewater treatment plant in this country are discussed. Then the effects on the design parameters of HGC of related factors such as the sewerage system, the setup of primary sedimentation tank and the selection of sand conveyer are discussed and a selected design criteria has been recommended. 为了减少城市污水处理系统中水泵与其它机械设备的磨损，保证沉淀池、曝气池等处理 构筑物功能的正常发挥，沉砂池是城市污水厂必不可少的预处理构筑物。 ,1, 竖流式沉砂池由于除砂效果差，运行管理不便，因而在国内外城市污水厂极少采用。 涡流式沉砂池虽然有占地小、除砂效率高等特点，并且在国外得到广泛应用，但是这种 池型及其除砂设备均为国外专利，其关键设备为国外产品，因此，涡流式沉砂池在国内的普 ,1,2,及为时尚早。 平流式沉砂池因构造简单，除砂效果较好，加之除砂设备国产化率高，已成为我国建成 城市污水厂沉砂池的主要池型。 虽然曝气沉砂池具有除砂效率高，尤其是有机物与砂分离效果好等优点，大有取代平流 式沉砂池之势，但在南方城市污水厂水质浓度较低的条件下，曝气沉砂池并不能充分发挥其 ,1，3,,4,优势。况且，曝气沉砂池的基本池型仍然是平流式沉砂池。毫无疑义，平流式沉砂 池在今后城市污水厂的建设中，仍将占有一席之地。因此，应充分重视平流式沉砂池的设计。 and municipal party Committee session plenary session, adding measures, promote the XX economic, social and cultural development. (A) the primary responsibility for fulfilling Party 5 years XX town guided by the 18 the spirit of the party, conscientiously implement the Central eight and three Suns and ten requirements of the provincial, city and County, put thought and action into County, the County Government a major deployment, and the County discipline Inspection Commission plenary session. Seriously studying and implementing the important speech, General Secretary of the Communist Party of China XI Jinping probity guidelines, the CPC disciplinary Ordinance, such as the responsibility of uncorrupted, to realize the Chinese dream built a well-off society has laid a solid political foundation. 1. strongly implementation Central, and provincial, and municipal and County of arrangements deployment, insisted put style clean government and economic development work with deployment, and with check, and with implementation, strong advance four wind highlight problem special regulation, constantly enhanced style clean government and anti-corruption struggle of suffering consciousness, and play consciousness, and responsibility consciousness, insisted to mass line in the of four mirror for guide, find out four wind highlight problem 12 a, effective do has side check side modified, change style, constantly improve political literacy, Strengthening the four winds problem rectification and conscientiously implement both, further efforts to improve the Party Committee on upholding integrity and combating corruption. Established by the Secretary of the responsibility of honest leadership team, and conscientiously implement the responsibility of uncorrupted party, firmly does not scratch clean is dereliction of duty, is 1 国内一些城市污水厂平流式沉砂池的运行现状 平流式沉砂池的设计一般按池内水平流速和停留时间来确定。国外平流式沉砂池的设计 ,5,参数:池内水平流速0.3m/s，停留时间60s;我国设计规范为池内水平流速0.15m/s,0.3m/s， ,6,停留时间(最大流量时)应不小于30s。 从按现行规范设计的国内城市污水厂内平流式沉砂池运行情况看，或多或少地存在影响后续处理构筑物正常运行的问题。试举如下两例为证: 例1 湖北某城市污水厂处理合流制城市污水，采用普通活性污泥法二级处理 工艺 钢结构制作工艺流程车尿素生产工艺流程自动玻璃钢生产工艺2工艺纪律检查制度q345焊接工艺规程 。污水处理工艺 流程 快递问题件怎么处理流程河南自建厂房流程下载关于规范招聘需求审批流程制作流程表下载邮件下载流程设计 如图1所示。 图1 平流式沉砂池设计参数取值:池内水平流速0.3m/s，停留时间30s。采用重力式快开阀排砂。污水厂运行后不久，就发生曝气池配水渠泥砂淤积，影响配水;曝气池、二沉池池底积砂严重，池容减少。以致每年需停产数次，对曝气池和二沉池进行清淤检修。 例2 广西某城市污水厂处理合流制城市污水，采用氧化沟二级生物处理工艺。污水处理工艺流程如图2所示。 图2 平流式沉砂池设计参数:池内水平流速0.3m/s，停留时间30s。采用链条式刮砂机除砂。该厂试运行期间，发现氧化沟内沉砂较多，尤其在氧化沟水流转弯处下方，沉砂堆高接近水面。虽经人工清淤，但收效甚微。运行期间，还多次发生辐流式二沉池排砂管堵塞现象。为解决这个问题，厂方不得不将二沉池排泥由定时排泥改为连续排泥。 2 影响平流式沉砂池设计参数取值的因素 2.1 排水体制 and municipal party Committee session plenary session, adding measures, promote the XX economic, social and cultural development. (A) the primary responsibility for fulfilling Party 5 years XX town guided by the 18 the spirit of the party, conscientiously implement the Central eight and three Suns and ten requirements of the provincial, city and County, put thought and action into County, the County Government a major deployment, and the County discipline Inspection Commission plenary session. Seriously studying and implementing the important speech, General Secretary of the Communist Party of China XI Jinping probity guidelines, the CPC disciplinary Ordinance, such as the responsibility of uncorrupted, to realize the Chinese dream built a well-off society has laid a solid political foundation. 1. strongly implementation Central, and provincial, and municipal and County of arrangements deployment, insisted put style clean government and economic development work with deployment, and with check, and with implementation, strong advance four wind highlight problem special regulation, constantly enhanced style clean government and anti-corruption struggle of suffering consciousness, and play consciousness, and responsibility consciousness, insisted to mass line in the of four mirror for guide, find out four wind highlight problem 12 a, effective do has side check side modified, change style, constantly improve political literacy, Strengthening the four winds problem rectification and conscientiously implement both, further efforts to improve the Party Committee on upholding integrity and combating corruption. Established by the Secretary of the responsibility of honest leadership team, and conscientiously implement the responsibility of uncorrupted party, firmly does not scratch clean is dereliction of duty, is 合流制排水系统接纳的城市污水不同于分流制排水系统。前者由于暴雨雨水对屋面、街道的冲刷，使得进入城市污水厂平流式沉砂池的合流制污水夹带大量来自建筑工地、燃烧小煤炉的泥砂、煤屑等杂质。如果平流式沉砂池池内水平流速过快、停留时间不够，许多杂质来不及沉淀，过快的水流将杂质带入后续处理构筑物，从而影响后续构筑物的运行，甚至危及整个污水厂的正常运行。与此相反，分流制排水系统接纳的生活污水，水量稳定，杂质量小，所以采取较大的池内水平流速和较短的停留时间，往往能达到理想的除砂效果。 2.2 初沉池 初沉池也是城市污水厂一种预处理构筑物，通常设置在沉砂池之后。其作用是降低城市污水中的悬浮固体浓度。按照城市污水二级处理工艺要求，有初沉池需要设置和不需要设置两种情况。 一般地，采取普通活性污泥法二级生物处理的城市污水厂需要设置初沉池。较长停留时间(1.0h,2.0h)的初沉池弥补了按现行规范设计的平流式沉砂池池内水平流速过快、停留时间过短的不足。大量来不及在平流式沉砂池沉淀的小粒径杂质在初沉池得到有效的沉淀，从而保证了曝气池、二沉池等处理构筑物的正常运行。这也是为什么设置在平流式沉砂池之后的初沉池排泥中无机物所占比例较大的原因。由此可见，本文例1中取消初沉池是不合理的。 在不需要设置初沉池的城市污水厂(如氧化沟处理工艺)，如果按现行规范设计平流式沉砂池，运行中，往往出现本文例2中的问题。根据对例2氧化沟内沉积物取样筛分，分析结果如表1所示。 表1 氧化沟内杂质筛分结果 杂质粒径/mm 杂质所占比例/% 0.1 63 0.15 25 0.2 9 0.25 3 表1中显示，平流式沉砂池(在设计水平流速0.3m/s，停留时间30s的情况下)尽管对0.2mm以上的杂质去除率达到了90%，但对0.1mm粒径的杂质，去除率仅为35%左右。 2.3 除砂设备 and municipal party Committee session plenary session, adding measures, promote the XX economic, social and cultural development. (A) the primary responsibility for fulfilling Party 5 years XX town guided by the 18 the spirit of the party, conscientiously implement the Central eight and three Suns and ten requirements of the provincial, city and County, put thought and action into County, the County Government a major deployment, and the County discipline Inspection Commission plenary session. Seriously studying and implementing the important speech, General Secretary of the Communist Party of China XI Jinping probity guidelines, the CPC disciplinary Ordinance, such as the responsibility of uncorrupted, to realize the Chinese dream built a well-off society has laid a solid political foundation. 1. strongly implementation Central, and provincial, and municipal and County of arrangements deployment, insisted put style clean government and economic development work with deployment, and with check, and with implementation, strong advance four wind highlight problem special regulation, constantly enhanced style clean government and anti-corruption struggle of suffering consciousness, and play consciousness, and responsibility consciousness, insisted to mass line in the of four mirror for guide, find out four wind highlight problem 12 a, effective do has side check side modified, change style, constantly improve political literacy, Strengthening the four winds problem rectification and conscientiously implement both, further efforts to improve the Party Committee on upholding integrity and combating corruption. Established by the Secretary of the responsibility of honest leadership team, and conscientiously implement the responsibility of uncorrupted party, firmly does not scratch clean is dereliction of duty, is 平流式沉砂池机械除砂设备一般有链条式刮砂机和行车式砂泵除砂机。这两种除砂设备除砂效果如何呢?对已建的位于南方同一城市的两座污水厂(水质相近)采用不同沉砂池、不同除砂机的除砂效率进行测定，结果如表2所示。 在表2中，似乎设置的沉砂池型及其设计参数不一样，采用的除砂设备也不一样，根本无法比较两种不同除砂设备的优劣。然而有一点是肯定的，那就是在停止曝气状态下的曝气沉砂池由于停留时间比平流式沉砂池长，池内水平流速比平流式沉砂池慢，因而对细小砂粒去除率比平流式沉砂池高得多。 表2 链条式刮砂机与行车式砂泵除砂机除砂效率 平流式沉砂池(链条式刮砂机) 曝气沉砂池(行车式砂泵除砂机) 设计参数:池内水平流速0.3m/s，设计参数:池内水平流速0.1m/s，停留时 停留时间30s。 间150s(2.5min)。 *砂粒粒径/mm 除砂效率/% 砂粒粒径/mm 除砂效率/% 0.1 31 0.1 79 0.15 70 0.15 88 0.20 89 0.20 95 0.25 93 0.25 98 *在停止曝气状态下的除砂效率。 在缺乏可比资料情况下，仍然可以从行车式砂泵除砂机和链条式刮砂机结构和除砂原理进行分析。 行车式砂泵除砂机采取砂泵抽吸沉砂，辅助砂水分离器的有效分离，使得该设备对细小砂粒的去除具有独特的优势。而链条式刮砂机的刮板刮砂动作与水流方向相反，由于刮板刮砂时的搅动与水流的作用，沉淀在沉砂池末端的细小砂粒在被刮至砂斗前，极易泛起随水流带入后续处理构筑物。换言之，链条式除砂机设置在曝气沉砂池上，远不如行车式砂泵除砂机除砂效率高。 and municipal party Committee session plenary session, adding measures, promote the XX economic, social and cultural development. (A) the primary responsibility for fulfilling Party 5 years XX town guided by the 18 the spirit of the party, conscientiously implement the Central eight and three Suns and ten requirements of the provincial, city and County, put thought and action into County, the County Government a major deployment, and the County discipline Inspection Commission plenary session. Seriously studying and implementing the important speech, General Secretary of the Communist Party of China XI Jinping probity guidelines, the CPC disciplinary Ordinance, such as the responsibility of uncorrupted, to realize the Chinese dream built a well-off society has laid a solid political foundation. 1. strongly implementation Central, and provincial, and municipal and County of arrangements deployment, insisted put style clean government and economic development work with deployment, and with check, and with implementation, strong advance four wind highlight problem special regulation, constantly enhanced style clean government and anti-corruption struggle of suffering consciousness, and play consciousness, and responsibility consciousness, insisted to mass line in the of four mirror for guide, find out four wind highlight problem 12 a, effective do has side check side modified, change style, constantly improve political literacy, Strengthening the four winds problem rectification and conscientiously implement both, further efforts to improve the Party Committee on upholding integrity and combating corruption. Established by the Secretary of the responsibility of honest leadership team, and conscientiously implement the responsibility of uncorrupted party, firmly does not scratch clean is dereliction of duty, is 3 平流式沉砂池设计参数的讨论 ,7, 对于所有沉砂池而言，沉砂效率首先取决于水力停留时间。追溯城市污水生物处理百年史，传统的普通活性污泥法一直居统治地位，初沉池设置在沉砂池后、曝气池前已作为固定处理流程普及开来。平流式沉砂池的设计参数是按去除粒径大于0.2mm的砂粒(比重为2.65)，去除率大于95%而确定的。然而，随着本世纪七八十年代革新的活性污泥法的发展 ,8,及初沉池的被取消，对城市污水预处理要求有了很大的变化。在平流式沉砂池基础上发展起来的曝气沉砂池较好地适应了这种变化，较慢的池内水平流速(0.06m/s,0.12m/s)，较长的停留时间(1min,3min)，使得曝气沉砂池除砂效率远高于平流式沉砂池。显然，面对日益发展起来的革新的活性污泥工艺，平流式沉砂池现行的设计参数已不适宜了。从沉砂池发展趋势看，采取较长的停留时间是沉砂池的发展方向。德国对曝气沉砂池停留时间的选择为: ,9,旱流流量时为20min，雨季流量时为10min就是明证。 4 结论与建议 (1)现行平流式沉砂池设计参数仅限后接初沉池、采取普通活性污泥法城市污水厂平流式沉砂池的设计; (2)链条式刮砂机适宜于后接初沉池的平流式沉砂池除砂; (3)行车式砂泵除砂机适宜于不设初沉池的城市污水厂沉砂池的除砂; (4)建议作进一步的研究，制定出平流式沉砂池新的设计规范。在新的设计规范未颁布前，平流式沉砂池设计宜按曝气沉砂池设计参数选择。 *国家九五攻关课题(96-909-01-01-09)。 ?作者通讯处:邵林广 430070 武汉武昌洪山石牌岭310号 武汉冶金科技大学环境工程系 王华 100044 建设部居住建筑与设备研究所 电话:(027)87390345(O) 87391339(H) 参考文献 and municipal party Committee session plenary session, adding measures, promote the XX economic, social and cultural development. (A) the primary responsibility for fulfilling Party 5 years XX town guided by the 18 the spirit of the party, conscientiously implement the Central eight and three Suns and ten requirements of the provincial, city and County, put thought and action into County, the County Government a major deployment, and the County discipline Inspection Commission plenary session. Seriously studying and implementing the important speech, General Secretary of the Communist Party of China XI Jinping probity guidelines, the CPC disciplinary Ordinance, such as the responsibility of uncorrupted, to realize the Chinese dream built a well-off society has laid a solid political foundation. 1. strongly implementation Central, and provincial, and municipal and County of arrangements deployment, insisted put style clean government and economic development work with deployment, and with check, and with implementation, strong advance four wind highlight problem special regulation, constantly enhanced style clean government and anti-corruption struggle of suffering consciousness, and play consciousness, and responsibility consciousness, insisted to mass line in the of four mirror for guide, find out four wind highlight problem 12 a, effective do has side check side modified, change style, constantly improve political literacy, Strengthening the four winds problem rectification and conscientiously implement both, further efforts to improve the Party Committee on upholding integrity and combating corruption. Established by the Secretary of the responsibility of honest leadership team, and conscientiously implement the responsibility of uncorrupted party, firmly does not scratch clean is dereliction of duty, is