蓝梅建筑给排水专业英语

1、Reading Material BCoagulation Facilities混凝设施Coagulation depends on the rapid reaction through which the coagulant destabilizes the colloids. Coagulation requires the rapid dispersion of the coagulant throughout the water. This is accomplished through very intense agitation and mixing. High shear rat

2、es are beneficial to coagulation. Flocculation depends on the frequency of collision of the destabilized colloids to form larger floc particles. The frequency of collision depends on the intensity of the agitation and the shear rate. However, too high a value of the agitation intensity and shear rat

3、e may break up the floc just formed. Therefore, moderate shear rates and agitation intensities are used in flocculators.混凝取决于通过混凝剂快速反应来破坏固体，混凝所需要的混凝剂迅速分散在水中，这是通过非常 激烈的搅拌和混合完成的，高的剪切速率有利于混凝。絮凝取决于胶体的碰撞频率，形成较大的絮凝颗 粒，碰撞的频率取决于搅拌的强度和剪切速率。然而，太高的搅拌强度和剪切速率可能会破坏形成的絮 凝体，因此，絮凝过程中应该使用适宜的剪切速率和搅拌强度。Flocculator is a

4、 piece of equipment that aids or performs flocculation, or the removal of contaminants in1 water by the use of flocculating agents to encapsulate and remove these solids or contaminants from solution .絮凝池是通过用絮凝剂去压缩和去除水中的固体或污染物，从而帮助或完成絮凝或污染物去除的一 种装置。Classification of power sources电源分类The power dissip

5、ated inside a tank must be supplied from the outside in some way. In principle, this external power can be supplied by means of three primary different sources, i.e.贮水池内部的能量必须以某种方式从外部供应，而这种外部能量可以通过三种主要手段来提供不同 来源。Mechanical agitation (e.g., impellers, paddles, turbines)Power delivered by a compressed

6、 gas (e.g., through gas dispersers, sparged gas diffusers) Power delivered by the liquid (e.g., venture mixers, hydraulic jumps, water jets) 机械搅拌(例如叶轮、桨、涡轮机)通过压缩气体传递能量(例如通过气体扩散、喷射的气体扩散器)通过液体流动传递能量(例如液体混合器、水跃、水射流)Types of flocculators设备类型The agitation required for flocculation is usually provided by

7、either hydraulic or mechanical means.絮凝所需的搅拌通常是液压或机械手段。Mechanical mixing flocculators (1)机械搅拌絮凝一 Vertical shaft with impeller (turbine or propeller type blades)一 Paddle type with either horizontal or vertical shafts- Walking Beam Flocculator一带叶轮的立轴(涡轮或螺旋桨式叶片)一卧式或立式的桨一步进梁式絮凝器Submerged impellers (mixe

8、rs) mounted on vertical shafts. Many different types of impellers exist. Impellers are classified on the basis of shape, dimensions, type of flow pattern generated, flow intensity , power consumption under aerated, nonaerated conditions and their ability to disperse a gas effectively. 2 Mechanical p

9、addle mixers in a flocculation basin with a detention time of 20 to 60 minutes are widely used in practice. Mechanical flocculators, consist of revolving paddles connected to horizontal or vertical shafts, driven by electric motor.垂直安装的浸入式叶轮混合器，存在许多不同类型的叶轮。叶轮种类很多，根据外形、尺寸、产生 的流动类型、流动强度、曝气和非曝气情况下能量消耗和

10、它们有效的分散气体的能力进行分类。机械桨 混合器在絮凝池中停留20到60min而被广泛的应用于实践中。而机械设备，包括螺旋桨连接在水平或垂直轴上，是由电动机驱动。Gravitational or hydraulic flocculator(2)重力或水力絮凝Baffle type mixing basins are examples of gravitational flocculation. Water flows by gravity and baffles are (r , .3 provided in the basins which induce the required veloc

11、ity gradients for achieving floc formation.挡板式混合池是重力絮凝的例子。水依靠重力流动，在池中安装挡板使速度梯度达到絮凝物形成条件。The most common hydraulic flocculator is the baffled basin in which a sinuous channel is equipped with either around-the-end or over-the-under baffles. The flocculation energy is derived primarily from the 180 ch

12、ange in direction of flow at each baffle.最常见的水力絮凝是挡板盆，弯曲的通道充满了在底部或在下部的隔板。絮凝的能量主要是来自每个挡板的流动方向的180度的变化。The baffle spacing should be increased gradually with channel length to achieve tapered flocculation. The floor of the channel should slope towards the outlet. The advantage of the baffle basin is it

13、s simplicity because there is no mechanical or moving equipment, and near plug flow conditions occur with low short-circuiting. The disadvantages are that most headloss occurs at the 180bends and therefore the value may be too high at the bends and inadequate in the straight channels for good floccu

14、lation, G value will vary as the flow Q varies(but this could be partly overcome by providing removable baffles ) and settlement of suspended solids in the channel.挡板间距应逐渐增加到通道长度实现锥形絮凝，通道的地板应该朝向出口处倾斜，挡板盆的其中一 个优点是它简单因为这里没有机械或移动设备，和附近的设备在塞流条件下很少发生短路。缺点是大多 数的水头损失发生在180度的弯曲处，因此弯曲处的能耗太高，而且在直的通道中不利于更好的絮凝。

15、G值会流量Q的变化而有所不同(但这可以通过提供可拆卸的挡板部分来克服)和通道中悬浮物的沉降。2There are two types of gravitational type baffled flocculator in practice as follows:这里有两种类型的重力式隔板絮凝池的实践如下：Horizontal flow baffled flocculatorVertical flow baffled flocculator水平流隔板絮凝池垂直流隔板絮凝池Horizontal flow baffled flocculator水平流隔板絮凝池The horizontal flow

16、 flocculator consists of several around the end baffles with in between spacing of not less than 45 cm to permit cleaning. Clear distance between the end of each baffle and the wall is about 1.5 times the distance between the baffles, but never less than 60 cm. Water depth shall not be less than 1.0

17、m and the water velocity is in the range of 10 to 30 cm/s. The detention time is between 15 to 20 minutes. This type of flocculator is well suited for very small treatment plants. It is easier to drain and clean. Paddles mounted on horizontal shafts are often encountered in flocculation tanks. Verti

18、cal flow baffled flocculator水平式絮凝器由几个底部挡板组成且底部挡板之间有不小于45cm的间距允许清洗，每个挡板的末端与墙之间的距离约为1.5倍的挡板之间的距离，但从不小于60cs水深不彳#小于1m而且水的流速范围在10到30cm/s,停留时间在15到20min之间。这类絮凝池适用于小型污水处理厂，因为它容易流失和 清洁。水平轴上安装桨经常在絮凝池中遇到。Vertical flow baffled flocculator垂直流隔板絮凝池This type of flocculator is used for medium to large size treatmen

19、t plants. In vertical flow baffled flocculator the distance between the baffles is not less than 45cm. Clear space between the upper edge of the baffles and the water surface or lower edge of the baffles and the basin bottom is almost 1.5 times the distance between the baffles. 4 / L , C , .,，Water

20、depth varies between 1.5 to 3 times the distance between the baffles and the water velocity is in the range of 10 to 20 cm/ s. The detention time is between 10 to 20 minutes.这类絮凝池适用于大中型污水处理厂。在垂直流隔板絮凝池之间白挡板距离应不小于45cm。隔板上边缘和水表面或隔板下边缘和池底的间隔距离大约是隔板间距离的1.5倍。水深变化在1.5到3倍的挡板距离而且水的流速变化范围在10到20cm/s,停留时间为10到20

21、min。Generalized approach to the design of coagulation and flocculation devices混凝装置设计的通用方法Carry out jar tests to determine dosage of coagulant.Assume values for G and the residence time.Size the tank for the residence time selected.Choose the type of equipment appropriate for the process (e.g., high

22、speed impeller for rapid mix or paddle agitator for flocculation).Size the equipment on the basis of the power dissipation that will result in the desiredG value.进行烧杯试验，确定混凝剂用量假设G值和停留时间根据贮水池的大小选择停留时间选择适合加工的设备类型（例如高速叶轮用于快速搅拌或桨搅拌器用于絮凝）测量该设备的基础功耗，该功耗将导致所需的G值变大Type of flocculator basic design criteria絮凝

23、池的基本设计标准Vertical shaft gave value up to 100 s-1, maximum tip speed of 2m/s, approximately 5m x 5m to 10m x 10m basin surface area per unit, downward flow pattern preferable for propeller unit, stator baffles should be provided for turbine units.垂直轴的最高值可达到100 s-1 ,最大速度可达到2m/s,约5mx5mU 10mx10m的单位流域面积，向

24、下流动的模式对螺旋桨装置是较好的，定子挡板应该提供汽轮机组。Horizontal-shaft paddle gave value up to 50s 1, maximum tip speed of 1 m/s, number of paddles adjusted for tapered mixing; paddle area should not exceed 20% of tank section area水平轴的最高值可达到50s-1 ,最大速度可达1m/s,大多数桨适用于锥形混合，桨叶面积不得超过贮水池截面面积的20%Baffled channel折流通道Tapered mixing

25、by adjusting baffles, maximum flow velocity of approximately 0.75 m/s, end-around baffle used when total head loss across tank is limited. Diffused air and water jets Gave = 95-20 s 1 or Gave t =105-106, may be used for auxiliary mixing when plant is overloaded.通过调节挡板的最大搅拌速率约为0.75m/s,当总水头损失被抑制时使用端部挡

26、板，扩散空气和水射流Gave = 95-20 s-1 或Gave ?t = 105 -106 ,当设备超载时可用于辅助混合。Table 8-1 Flocculator design guidelinesType of FlocculatorAdvantages and DisadvantagesVertical shaftEasy maintenance and few breakdowns. Suitablefor high-energy input. Suitable for direct filtrationand conventional treatment. Many units requiredfor a large plant. High capitalcost forvariable-speed reducers and support slabs.Horizontal-shaftPaddleGenerally produces a large-size floc. Simple mixing it. Suitable for conventionaltreatment.Need for precise installation and maintenance.