基于PLC的控制系统在污水处理中的应用外文翻译
外文翻译
译文：
Application of control system on the base of PLC in
sewage treatment
The paper introduces a distributed control system of sewage treatment, and the core of the system is PLC. The structure of the control system, the assignment and implementation of the tasks, the control scheme and the design concept of program are expounded. The way of central monitoring management and dispersing control is used by the control system; the long一distance control and monitoring of field equipment are uncharged of the upper computer; the software program of designs uses Intouch7. 0. The specific technology, equipment, the controlling of main parameter and several running data are uncharged of the PLC stations, and the software program of designs uses Concept 2. 2XL with online tracking and outline simulating. MB+ net is adopted by the communication between the upper computer and the PLC stations, with its simply building net, quickly running and stable communication. The automatic control of PLC has been successfully completed in sewage treatment, which has improved the operation efficiency and management level of sewage treatment equipment
Introduced to take PLC as the distribute type control system of core in the wastewater treatment system of apply。Concretely described the structure, mission of the control system an allotment and carry out, the way of control and the thought of the program design.The way controled the concentration monitor of the system adoption a management and scattered a control, the place of honor machine be responsible for the spot the long range of the equipments control and surveillance, software adoption Intouch7. 0 draw up.The PLC native station is responsible for to the concrete craft, equipments and is mainly controled parameter to carry on control and collect various movement data, the program design adoption have on-line follow with off-line imitate the Concept of true function 2. 2 XL software.Place of honor machine and of the PLC adoption set the net be quickly simple and circulate speed, correspond by letter the stability strong MB+net.The whole control system successfully solved the PLC controls a problem in the automation within wastewater treatment and raised a wastewater treatment equipments to circulate an efficiency and manage level.
Recently, for carrying out high quality, low consume, stable dependable movement.Domestic and international many wastewater treatment factorieses adopted a modern forerunner to control technique and calculator technique and constitute calculator direct, control thus, manage system.Make system excellent to turn movement.But the programmable logic controller(PLC) then take microprocessor as
core.Synthesize the calculator technique automatically controls technique and correspondence technique but develops of a kind of new and in general use utomatic control device.Have structure simple, function superior, dependable sex Gao, work properly words in general use, be easy to plait distance, usage convenience etc. advantage etc..The silver Chuan City the first wastewater treatment factory adopted a SBR craft and take PLC as the control system of core, day after handling the sewage 10 ×104 t the processing of reach mark sewage can used for an agriculture irrigation.
1 Control system structure
Control the way of "concentration monitor management, scatter a control" of the system adoption.The emulation hold, place of honor machine, gather a line machine, printer to Be located on medium control room, two set PLCs are located on control the spot.Adopt this kind of structure can make the information in the production line can centralized management with carry out whole operation, management with excellent turn.Also make to control dangerous dispersion in the meantime, raise the system credibility.
1.1 The upper computers
Medium control two calculator adoption PII class works of room to control machine, circulate the operate system of Windows NT.The place of honor machine be responsible for on the scene establish each long range control(full-automatic control, automatic control, order to move a control) with surveillance, make use of Intouch7. 0 engineering software packages provide a good person machine dialogue boundary but obtain concerning parameter and equipments appearance information from the PLC by searching a way, keep a view manifestation to come out on the CRT by good sketch type, print a necessary data in the meantime and be provided for lord to control and manager instruction produce.Supervise and control boundary but include the system total diagram, system cent diagram, imitate the quantity general chart, parameter a constitution, report to the police a window, history trend and register a window etc. boundary but.In the system total diagram, circulate the personnel can keep watch on signals, such as all movement appearances, equipments trouble and liquid which control an equipments and discharge...etc..Operate a personnel in the system the cent the diagram can carry on a single machine point to move to circulate an operation to all control equipmentses, become the set automatically circulate operation or the whole factorieses full-automatic operation combine surveillance.In the meantime place of honor machine 2 and do a plait distance a machine.Medium control room to establish another an inset type emulation to hold, is been one control by the place of honor machine, in order to keep the craft process of the view manifestation whole factory and main parameter value.
1. 2 The PLC stand
According to wastewater treatment of two part, the spot the long range of the equipments the control output and the spot the signal collect to control a station completion from two PLC wood ground.PLC1 native control station control the space grid, sewage promote a pump house, Pu spirit to sink sand pond's etc. to prepare a processing part.The PLC2 native control station controls dirty mire to dehydrate,
press to filter machine etc. department..PLC3 native control station control SBR living creature processing part.Moreover, the on the spot native control station is each to establish an operation terminal to establish each, be responsible for at native to establish each control on the scene.(automatic control, order to move a control) The spot is each the physical parameter that the supervision order and include water level, temperature, discharge and turn soon, electric current's etc. imitate quantity, from to in response to of an appearance spread a feeling machine or change to send to a machine examination to come out and change into the electric current signal of the 4~20 mA, through shield inside the PLC that the electric cable sends to each statures system, from the PLC picks up a people through various mold piece sample telecommunication number.Same, imitate quantity control the signal send to performance organization by the 4~20 mA electric current form after being output by the PLC, control performance organization of action.
The Modicon Quantum series PLC of Schneider company is satisfy liberal of, according to standard of network conjunction and the spot total line conjunction etc. application the technique provided various network a choice, support Modbus,
Mod-bus Plus(MB+), the long range I/0, TCP/IP etc. network conjunction, have stronger and vivid.Therefore, the wastewater treatment is convenient to arrive of the PLC choose the series of Modicon Ouantum of use Schneider.
1. 3 Correspondences
MB+agreement is the Modicon company release of an open type of the adoption IEEE802. 4 correspond by letter 5 agreements the spot total line of card agreement.MB+the network together other networks compare to have a set of net simple, the investment be little, network speed quick, correspondence the stability strong etc. characteristics, it make calculator, controller and other data sources through an usage double wring line or fiber optic cable Be a body to together carry on correspondence at the whole network top.But the CPU mold piece of the Modicon Quantum series PLC imply MB+correspondence, therefore correspond by letter a network to choose to use MB+network.Medium control two machine, two control stations with native PLC of room to pass MB+the network link together.The PLC CPU mold piece passes MB+correspondence and two machines carry on data commutation and collect the place of honor supervision various operation instruction of the system and the spot the examination signal and data, through analysis handle, pass exportation mold piece to control object output control signal;In the meantime, the PLC passes MB+net upward the machine return to various data, place of honor machine logarithms according to carry on an operation processing, show various signal and print various statement.
2 The design of PLC control program
The system has four kinds of control methods:The native hand moves a control, single set equipments point moves a control, become a set, the equipments automatically controls, the whole factory equipments full-automatic control.Two kinds of ex- with general methods at establish each adjust to try or maintain usage, the system is mainly circulate with full-automatic control.Under this kind of way, all each kind of equipmentses from PLC according to in advance draw up of procedure auto
control, don't need to operate a personnel an intervention.Various spot data spreads a highest machine through a PLC, come out in the place of honor on board description and make the craft, equipments movement of whole factorieses get an overall control.
The living creature processing part of the PLC3 station control is the whole wastewater treatment of key part, be limited by space, only with the PLC3 stand of program design for example.
2.1 Process of control
The PLC3 stationses were use to control to get into Pu spirit from sewage, the pond is everywhere sewage run off Pu after manage spirit the whole process of the pond.Include turn of sequence and time- switch moderate breezes machine of control various valve, pump, breeze machine to soon regulate etc. in this process.The Pu spirit pond is the core of wastewater treatment to construct a thing, sewage is to come and go through a microbial living creature oxygenation in the pond in addition to organic matter, the processing effect of content to sewage of the oxygen in water is to go to a pass important.Request according to the SBR craft, the deliquescence oxygen in the Pu spirit pond content usually controls within the scope of 1~3 mgs/L and annoy a stage end to fuse an oxygen content in the Pu should be not over the 2 mgs/L.Contain the oxygen once measured low or lead Gao, all will influence a fluid matter quantity.Handle 4 sets of the 10 ×104 t the SBR of 8 pond modes to respond pond to the day, each one responds that the pond go together with a pedestal from change Pin machine control of breeze machine, used for annoying pond Pu spirit to by turn provide oxygen toward two Pus.Establish 4 pieces of deliquescence oxygen test instruments in the different location of each Pu spirit pond, measure contain of sewage amount of oxygen in pond, the PLC separates a 5 mins to examine a deliquescence oxygen in a Pu spirit pond value each time, according to fuse oxygen of average value to control breeze machine to turn soon.If fuse oxygen low limit at the bottom of the enactment, the frequency modulation breeze machine turns to soon increase 5%;If fuse oxygen Gao while set upper limit, the frequency modulation breeze machine turns to soon lower 5%.So, carried out Pu spirit pond to provide automatically regulate of the amount of oxygen, since avoided unnecessary energy loss, again excellent turned movement craft.
2. 2 The design of PLC program
The adoptive plait distance software is a Concept 2. 2 XLs.Concept is according to under the Windows of the PLC plait distance tool, have good customer's interface, and have on-line follow and off-line imitate true function.The control procedure of PLC3 stationses is divided into five procedure mold piece.
(1)Public mold pieces of procedure use-include a beginning to start to turn part, hour cent second etc. ask pulse unit, SBR to respond a period enactment, fuse oxygen enactment...etc..
(2)Order control mold pieces of the switch quantity -the coordination control report to the police of circulate and related breakdown of equipmentses, such as each valve, pump and breeze machine...etc.. The enter of SBR pond spirit valve, enter water valve, reflux pump, surplus dirty mire pump from PLC according to the craft of the wastewater treatment period time segment control, water valve from PLC
according to craft time and super voice liquid the measured value of the instrument to control.
(3)Protection mold pieces of the off-power-system power failure after, the PLC saves all appearance locks and make after treating to add an electricity PLC instauration keep of the appearance continue to circulate.
(4)Mold pieces of correspondences -use to complete PLC and various data transmission of place of honor machine.
(5)Fuse an oxygen value to automatically regulate a mold piece-according to fuse an oxygen value to regulate breeze machine to turn soon and report to the police of related breakdown.The target which regulates to turn soon promises the be worth of deliquescence oxygen as 2 mgs/L in the whole Pu spirit period.Adoptive control strategy is as follows:The Pu spirit period beginning, the breeze machine at top speed movement attains a 2 mgs/L in shorterly of the hour ask by making deliquescence oxygen and take 5 mins as a period to examine deliquescence oxygen to be worth in the meantime.When fuse an oxygen value big at the 2 mgs/L, the breeze machine turns to soon descend 5%;When fuse an oxygen value small at the 2 mgs/L, the breeze machine turns to soon rise 5%.If the breeze machine turns to soon rise to allow of tallest turn soon, fuse an oxygen value return small then maintain tallest to turn soon at the 2 mgs/L.This kind of circumstance may annoy the last phase of period to appear in the Pu, but also will not clearly influence wastewater treatment quality.
Supervise and control an exportation electric current of change the Pin machine value at any time in the Pu the spirit of the whole period, make it not exceed change the sum of Pin machine settle a value.If meet a surprised circumstance to make to output electric current exceed when the sum settle value, immediately lower breeze machine to turn soon.If the breeze machine turns to soon decline to allow of lowest turn soon, output electric current to return exceed the sum settle a value, then stop breeze machine and send out to report to the police signal in the meantime Along with automatic control technical development, the UNITANK craft more and more gets extensively applied.Regard experience as principle currently, use DO, time, discharge as a craft control parameter, adjust the Pu spirit circulate of machine and line up mire the etc. lack accurate mathematics model to carry out the automatic control of higher layer of SBR method for time.Someone once put forward took the COD or the do as parameter of misty control of thought.The research direction of the automatic control of SBR method mainly is to look for several control parameters from now on, since can reflect into water of fluid matter water quantity variety and reaction process in of decline a solution circumstance, and then can do for the calculator control parameter.
The PLC gathers in proper order control and process to control at the integral whole and have dependable sex Gao, usage convenience, vivid, set net simple of the characteristics be the emollient tool of the small scale industrial automation in the realization.In the wastewater treatment, according to PLC control system at solid sex, credibility, accurate sex etc. dint a but satisfied a design a request, promised wastewater treatment of smoothly progress.
Because of Internet fast development, hope can come to visit to ask wastewater
treatment factory through an Internet of from control system, the Internet which needed to input user's name and password and then can carry out long range came to carried on a control to the equipments of whole factorieses.Transport the sewage data of wastewater treatment factory to the national environmental protection bureau through an Internet in the meantime city environmental protection bureau perhaps, for the purpose of the Bu class management of section to wastewater treatment factory.
基于PLC的控制系统在污水处理中的应用
介绍了以PLC为核心的分布式控制系统在污水处理系统中的应用。具体叙述了控制系统的结构、任务分配及实现、控制方式和程序设计思想.控制系统采用集中监测管理、分散控制的方式，上位机负责现场设备的远程控制和监视，软件采用Intouch7. 0编制。PLC本地站负责对具体的工艺、设备、主要被控参数进行控制及采集各种运行数据，程序设计采用具有在线跟踪和离线仿真功能的Concept 2. 2XL软件。上位机与PLC之间采用组网简单、运行速度快、通信稳定性强的MB+网。整个控制系统成功地解决了PLC在污水处理中的自动化控制问题，提高了污水处理设备运行效率和管理水平。
近年来，为了实现高质量、低消耗、稳定可靠的运行。国内外许多污水处理厂采用了现代先进控制技术和计算机技术，从而构成计算机监督、控制、管理系统.使系统优化运行。而可编程逻辑控制器（PLC）则是以微处理器为核心。综合了计算机技术自动控制技术和通信技术而发展起来的一种新型、通用的自动控制装置。具有结构简单、性能优越、可靠性高、灵话通用、易于编程、使用方便等优点等。银川市第一污水处理厂采用了SBR工艺及以PLC为核心的控制系统，日处理污水10 x 104 t处理后的达标污水可用于农业灌溉。
1 控制系统结构
控制系统采用“集中监测管理，分散控制”的方式。模拟屏、上位机、集线器、打印机位于中控室，二台PLC位于控制现场。采用这种结构可使生产过程中的信息能够集中管理，以实现整体操作、管理和优化。同时，也使得控制危险分散，提高系统可靠性。
1.1上位机
中控室的两台上位计算机采用PII级工控机，运行Windows NT操作系统。上位机负责现场设各的远程控制(全自动控制、自动控制、点动控制)和监视，利用Intouch7. 0工程软件包提供良好的人机对话界而，以查询方式从PLC获取有关参数和设备状态信息，以棒图形式在CRT上直观显示出来，同时打印必要的数据，供主控及管理人员指导生产。监控界而包括系统总图、系统分图、模拟量一览表、参数设置、报警窗、历史趋势、登录窗等界而.在系统总图里，运行人员能够监视所有控制设备的运行状态、设备事故及液位、流量等信号.在系统分
图里，操作人员能够对所有控制设备进行单机点动运行操作、成组自动运行操作或全厂全自动操作并监视。同时上位机2兼做编程器.中控室另设置一个镶嵌式模拟屏，由上位机1控制，用以直观显示全厂工艺流程及主要参数值。
1.2 PLC站
根据污水处理的二部分，现场设备的远程控制输出和现场信号采集由二个PLC木地控制站完成。PLC1本地控制站控制格栅、污水提升泵房、曝气沉砂池等预处理部分。PLC2本地控制站控制污泥脱水、压滤机等部。PLC3本地控制站控制SBR生物处理部分.另外，在现场本地控制站各设1台操作终端设各，负责在本地对现场设各的控制(自动控制、点动控制)。
现场各个监控点的物理参数，包括水位、温度、流量、转速、电流等模拟量，由对应的一次仪表传感器或变送器检测出来并转变为4～20 mA电流信号，经屏蔽电缆送到各个子系统的PLC内，由PLC通过各种模块接口采样电信号。同样，模拟量控制信号由PLC输出后以4～20mA电流形式送到执行机构，控制执行机构的动作。
施耐德公司的Modicon Quantum系列PLC为满足开放的、基于标准的网络连接和现场总线连接等应用技术提供了多种网络选择，支持Modbus,Mod-bus Plus（MB+），远程I/0, TCP/IP等网络连接，具有较强的灵活性。因此，污水处理中用到的PLC选用施耐德的Modicon Ouantum系列。
1.3通信
MB+协议是Modicon公司推出的一个开放式的采用IEEE802. 4令牌协议的现场总线通信5协议。MB+网络同其他网络相比具有组网简单、投资少、网络速度快、通信稳定性强等特点，它使计算机、控制器和其他数据源通过使用双绞线或光缆在整个网络上作为同位体进行通信。而Modicon Quantum系列PLC的CPU模块含有MB+通信口，因此，通信网络选用MB+网络.中控室的两台上位机、二个PLC本地控制站通过MB+网络连接在一起。PLC的CPU模块通过MB+通信口与两台上位机进行数据交换，采集上位监控系统的各种操作指令及现场检测信号和数据，经过分析处理，通过输出模块向控制对象输出控制信号；同时，PLC通过MB+网向上位机返回各种数据，上位机对数据进行运算处理，显示各种信号和打印各种报表。
2 PLC控制程序设计
系统有四种控制方式：本地手动控制，单一台设备点动控制，成组设备自动控制，全厂设备全自动控制。前二种方式一般只在设各调试或维修时使用，系统主要以全自动控制方式运行。在这种方式下，所有各类设备都由PLC按照预先编制的程序自动控制，不需要操作人员干预.各种现场数据通过PLC传至上位机，在上位机上描绘出来，使全厂的工艺、设备运行得到全面的控制。
PLC3站控制的生物处理部分是整个污水处理的关键部分，限于篇幅，仅以PLC3站的程序设计为例。
2.1控制过程
PLC3站用来控制从污水进入曝气池到处理后的污水流出曝气池的整个过程。在这个过程中，包括控制各种阀、泵、风机的顺序及定时开关和风机的转速调节等。曝气池是污水处理的核心构筑物，污水在池中是通过微生物的生物氧化作用来去除有机物的，水中氧的含量对污水的处理效果是至关重要的。根据SBR 工艺要求，曝气池内的溶解氧含量通常控制在1～3 mg/L范围内，在曝气阶段末溶解氧含量应不超过2 mg/L.含氧量过低或过高，均会影响出水质量。对日处理
10 x 104 t的4组8池模式的SBR反应池，每组反应池配一台由变频器控制的风机，用于向两个曝气池轮流曝气供氧。在每个曝气池的不同地点设4块溶解氧测试仪，测量池中污水的含氧量，PLC每隔5 min检测一次曝气池内的溶解氧值，根据溶解氧的平均值来控制风机转速。若溶解氧低于设定下限时，调频风机转速增加5 % ；若溶解氧高于设定上限时，调频风机转速降低5 %.这样，就实现了曝气池供氧量的自动调节，既避免了不必要的能源损失，又优化了运行工艺。2.2 PLC程序设计
采用的编程软件是Concept 2. 2XL。Concept是基于Windows下的PLC编程工具，具有良好的用户界面，并具有在线跟踪及离线仿真功能。PLC3站的控制程序分为五个程序模块。
（1）公用程序模块——包括初始化部分、时分秒等时问脉冲单元、SBR反应周期设定、溶解氧设定等。
（2）开关量顺序控制模块——协调控制各个阀、泵、风机等设备的运行及相关故障的报警。SBR池的进气阀、进水阀、回流泵、剩余污泥泵由PLC根据污水处理周期的工艺时间段控制，出水阀由PLC根据工艺时间和超声液位仪的测量值来控制。
（3）断电保护模块——系统断电后，PLC将所有状态锁存，待加电后使PLC 恢复所保持的状态继续运行。
（4）通信模块——用来完成PLC与上位机的各种数据传送。
（5）溶解氧值自动调节模块——根据溶解氧值调节风机转速以及相关故障的报警。调节转速的目标是在整个曝气周期中，保证溶解氧的值为2 mg/L.采用的控制策略如下：曝气周期开始，风机以全速运行，以使溶解氧在较短的时问内达到2 mg/L，同时以5 min为周期检测溶解氧值。当溶解氧值大于2mg/L时，风机转速下降5 %；当溶解氧值小于2 mg/L时，风机转速上升5%.如果风机转速升到允许的最高转速时，溶解氧值还小于2mg/L，则维持最高转速。这种情况有可能在曝气周期的末期出现，但并不会明显地影响污水处理质量。
在曝气的整个周期内，随时监控变频器的输出电流值，使其不超过变频器的额定值。如遇到意外情况使输出电流超过额定值时，立即降低风机转速。如果风机转速降到允许的最低转速时，输出电流还超过额定值，则停风机，同时发出报警信号。
随着自动控制技术的发展，UNITANK工艺越来越得到广泛应用。目前以经验为主，以DO、时间、流量作为工艺控制参数，来调整曝气机的运行及排泥时间等，缺乏准确的数学模型来实现SBR法的更高层次的自动控制。有人曾提出以COD或DO为参数的模糊控制的思想。今后SBR法的自动控制的研究方向主要是寻找多个控制参数，既能反映进水的水质水量变化及反应过程中的降解情况，又能作为计算机控制参数。
PLC集顺序控制和过程控制于一体，具有可靠性高，使用方便、灵活，组网简单的特点，是实现中小规模工业自动化的有力工具。在污水处理中，基于PLC 的控制系统在实时性、可靠性、精确性等力一而满足了设计要求，保证了污水处理的顺利进行。
由于Internet的快速发展，希望能够通过Internet来访问污水处理厂的自控系统，只需要输入用户名和密码便可实现远程的Internet来对全厂的设备进行控制。同时通过Internet将污水处理厂的污水数据输送到国家环保总局或者市环保局，以便卜级部门对污水处理厂的管理。
冲压模具技术外文翻译(含外文文献)
前言 在目前激烈的市场竞争中，产品投入市场的迟早往往是成败的关键。模具是高质量、高效率的产品生产工具，模具开发周期占整个产品开发周期的主要部分。因此客户对模具开发周期要求越来越短，不少客户把模具的交货期放在第一位置，然后才是质量和价格。因此，如何在保证质量、控制成本的前提下加工模具是值得认真考虑的问题。模具加工工艺是一项先进的制造工艺，已成为重要发展方向，在航空航天、汽车、机械等各行业得到越来越广泛的应用。模具加工技术，可以提高制造业的综合效益和竞争力。研究和建立模具工艺数据库，为生产企业提供迫切需要的高速切削加工数据，对推广高速切削加工技术具有非常重要的意义。本文的主要目标就是构建一个冲压模具工艺过程，将模具制造企业在实际生产中结合刀具、工件、机床与企业自身的实际情况积累得高速切削加工实例、工艺参数和经验等数据有选择地存储到高速切削数据库中，不但可以节省大量的人力、物力、财力，而且可以指导高速加工生产实践，达到提高加工效率，降低刀具费用，获得更高的经济效益。 1.冲压的概念、特点及应用 冲压是利用安装在冲压设备（主要是压力机）上的模具对材料施加压力，使其产生分离或塑性变形，从而获得所需零件（俗称冲压或冲压件）的一种压力加工方法。冲压通常是在常温下对材料进行冷变形加工，且主要采用板料来加工成所需零件，所以也叫冷冲压或板料冲压。冲压是材料压力加工或塑性加工的主要方法之一，隶属于材料成型工程术。 冲压所使用的模具称为冲压模具，简称冲模。冲模是将材料（金属或非金属）批量加工成所需冲件的专用工具。冲模在冲压中至关重要，没有符合要求的冲模，批量冲压生产就难以进行；没有先进的冲模，先进的冲压工艺就无法实现。冲压工艺与模具、冲压设备和冲压材料构成冲压加工的三要素，只有它们相互结合才能得出冲压件。 与机械加工及塑性加工的其它方法相比，冲压加工无论在技术方面还是经济方面都具有许多独特的优点，主要表现如下； (1) 冲压加工的生产效率高，且操作方便，易于实现机械化与自动化。这是
污水处理的英文文献翻译
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PLC外文文献翻译
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分与分流污水一起经污水预处理构筑物进入污水处理构筑物外，另一部分可考虑通过雨污溢流构筑物进入雨污溢流沉定池后排入附近水体。为了对进入污水处理构筑物的合流污水高峰流量、水质波动进行缓冲调节，污水处理构筑物前端可设缓冲调节池以均衡水质、储存水量。 2. 具有可靠的 BOD、 COD、 SS 去除功能及氮磷去除功能，保证最终出水水质稳定。通常情况下，城市污水中难降解有机物较少， BOD、 COD 去除比较容易实现，而氮磷去除则较复杂。我国现行的污水排放标准对污水处理厂出水氮磷指标有严格的要求，故城市污水处理都必须达到氮磷的有效去除。在现行城市污水脱氮除磷工艺中， A2/0 采用较为广泛。针对 A2/0 工艺存在的问题目前出现了许多改进工艺，每种工艺又都存在各自的特点和局限。由于合流污水引起的水质、水量波动较大，对污水厂各处理单元产生冲击，为了适应受纳水体的要求，为使 BOD、COD 等指标进一步降低，进一步去除污水中的细菌及氮、磷等植物性营养物质，在污水厂与受纳水体之间可设氧化塘。 3. 具有灵活多变的运行方式，可根据收集的污水量、进水水质以及季节变化调整运行方式。常规 A2/0 工艺，很难做到灵活方便地调整运行方式。但 A2/0工艺从构成原理上讲，是在曝气段前 加厌氧段和缺氧段。这一原理用于氧化沟技术，便可形成各种适应不同水质、水量、季节变化的运行方式。污水厂可根据实际情况设两个以上的氧化沟，每个沟设一定数量的水力推进器，池底均匀分布微孔爆气器。通过调整氧化沟污水进水管阀门、曝气器的开及关的区域、内回流比大小、污泥回流比大小及水力推进器运行个数，便可形成串联、并联等若干种运行方式。每种运行方式具有各自区域大小不同的厌氧段、缺氮段、曝气段。当旱季污水量小则采用串联运行方式，雨季污水量大，则采用并联运行方式。夏季温度高，硝化反应速度快，则采用具有较小曝气区域、较小硝化段的运行方式，相应反硝化区域
基于单片机的步进电机控制系统设计外文翻译
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机械类外文翻译
机械类外文翻译 塑料注塑模具浇口优化 摘要:用单注塑模具浇口位置的优化方法，本文论述。该闸门优化设计的目的是最大限度地减少注塑件翘曲变形，翘曲，是因为对大多数注塑成型质量问题的关键，而这是受了很大的部分浇口位置。特征翘曲定义为最大位移的功能表面到表面的特征描述零件翘曲预测长度比。结合的优化与数值模拟技术，以找出最佳浇口位置，其中模拟armealing算法用于搜索最优。最后，通过实例讨论的文件，它可以得出结论，该方法是有效的。 注塑模具、浇口位臵、优化、特征翘曲变形关键词: 简介 塑料注射成型是一种广泛使用的，但非常复杂的生产的塑料产品，尤其是具有高生产的要求，严密性，以及大量的各种复杂形状的有效方法。质量ofinjection 成型零件是塑料材料，零件几何形状，模具结构和工艺条件的函数。注塑模具的一个最重要的部分主要是以下三个组件集:蛀牙，盖茨和亚军，和冷却系统。拉米夫定、Seow(2000)、金和拉米夫定(2002) 通过改变部分的尼斯达到平衡的腔壁厚度。在平衡型腔充填过程提供了一种均匀分布压力和透射电镜,可以极大地减少高温的翘曲变形的部分～但仅仅是腔平衡的一个重要影响因素的一部分。cially Espe,部分有其功能上的要求,其厚度通常不应该变化。 pointview注塑模具设计的重点是一门的大小和位臵,以及流道系统的大小和布局。大门的大小和转轮布局通常被认定为常量。相对而言,浇口位臵与水口大小布局也更加灵活,可以根据不同的零件的质量。 李和吉姆(姚开屏,1996a)称利用优化流道和尺寸来平衡多流道系统为multiple 注射系统。转轮平衡被形容为入口压力的差异为一多型腔模具用相同的蛀牙,也存
污水处理外文翻译---污水的生物处理过程
附录Ⅰ： Wastewater Biological Treatment Processes The objective of wastewater treatment is to reduce the concentration of specific pollutants to the level at which the discharge of the effluent will not adversely affect the environment or pose a health threat. Moreover , reduction of these constituents need only be to some required level. For any given wastewater in a specific location , the degree and type of treatment are variables that require engineering decisions . often the degree of treatment depends on the assimilative capacity of the receiving water . DO sag curves can indicate how much BOD must be removed from wastewater so that the DO of receiving water is not depressed too far . The amount of BOD that must be removed is an effluent standard and dictates in large part the type of wastewater treatment required . To facilitate the discussion of wastewater , assume a “ typical wastewater ”and assume further that the effluent from this wastewater treatment must meet the following effluent standards : BOD≤15mg/L SS≤15mg/L P≤1mg/L Additional effluent standard could have been established , but for illustrative purposes we consider only these three . The treatment system selected to achieve these effluent standards includes 1. Primary treatment : physical processes that nonhomogenizable solids and homogenize the remaining effluent . 2. Secondary treatment : biological process that remove most of the biochemical demand for oxyen . 3. Tertiary treatment : physical , biological , and chemical processes to remove nutrients like phosphorus and inorganic pollutants , to deodorize and decolorize effluent water , and to carry out further oxidation .
速度控制系统设计外文翻译
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机械图纸中英文翻译汇总
近几年，我厂和英国、西班牙的几个公司有业务往来，外商传真发来的图纸都是英文标注，平时阅看有一定的困难。下面把我们积累的几点看英文图纸的经验与同行们交流。 1标题栏 英文工程图纸的右下边是标题栏（相当于我们的标题栏和部分技术要求），其中有图纸名称（TILE）、设计者（DRAWN）、审查者（CHECKED）、材料（MATERIAL）、日期（DATE）、比例（SCALE）、热处理（HEAT TREATMENT）和其它一些要求，如： 1)TOLERANCES UNLESS OTHERWISE SPECIFIAL 未注公差。 2)DIMS IN mm UNLESS STATED 如不做特殊要求以毫米为单位。 3)ANGULAR TOLERANCE±1°角度公差±1°。 4)DIMS TOLERANCE±0.1未注尺寸公差±0.1。 5)SURFACE FINISH 3.2 UNLESS STATED未注粗糙度3.2。 2常见尺寸的标注及要求 2.1孔（HOLE）如： （1）毛坯孔：3"DIAO+1CORE 芯子3"0+1; （2）加工孔：1"DIA1"; （3）锪孔：锪孔(注C＇BORE=COUNTER BORE锪底面孔); （4）铰孔：1"/4 DIA REAM铰孔1"/4; （5）螺纹孔的标注一般要表示出螺纹的直径，每英寸牙数（螺矩）、螺纹种类、精度等级、钻深、攻深，方向等。如： 例1.6 HOLES EQUI-SPACED ON 5"DIA (6孔均布在5圆周上（EQUI-SPACED=EQUALLY SPACED均布） DRILL 1"DIATHRO＇ 钻1"通孔（THRO＇=THROUGH通） C/SINK22×6DEEP 沉孔22×6 例2.TAP7"/8-14UNF-3BTHRO＇ 攻统一标准细牙螺纹，每英寸14牙，精度等级3B级 （注UNF=UNIFIED FINE THREAD美国标准细牙螺纹） 1"DRILL 1"/4-20 UNC-3 THD7"/8 DEEP 4HOLES NOT BREAK THRO钻 1"孔，攻1"/4美国粗牙螺纹，每英寸20牙，攻深7"/8,4孔不准钻通（UNC=UCIFIED COARSE THREAD 美国标准粗牙螺纹）
基于PLC相关的毕业设计外文翻译(可编辑修改word版)
毕业论文（设计）外文翻译 题目：可编程逻辑控制器技术 系部名称：信息工程系专业班级： 学生姓名：学号： 指导教师：教师职称： 2014 年3 月XX 日
译文 可编程逻辑控制器技术 引言 PLC（可编程逻辑控制器）实际是一个工业控制系统（近来我们看到更多的是用处理器来取代微控制器），在软件和硬件都配备的条件下，适合应用于工业环境。PLC 的发明是相当必要的，它代替了传统的依靠由继电接触器电路来控制电机。PLC 的工作原理是根据它的输入信号和工作状态来确定输出。用户通常是通过软件或编程输入一个程序，来输出所需要的结果。 如图 8-1 所示，PLC 是由典型的黑色构件组成。特别需要注意的是它的输入和输出， 因为在这些模块上，工业环境会给 CPU 一个输入线，所以很有必要将 CPU 模块隔离以保护其免遭有害的影响。程序单元通常是用计算机来编写程序（一般是梯形图）。 1.1CPU 的中央处理单元 中央处理单元（CPU）是一个 PLC 的主控制器。一般 CPU 本身是一个微控制器。通常这些都是 8 位微控制器，如 8051 ，现在的这些是 16 位和 32 位微控制器。潜规则是，你会发现用在 PLC 控制器上的微控制器多数是由日本生产的日立和富士通，欧洲的西门子控制器，和美国的摩托罗拉微控制器。CPU 也负责通讯，与 PLC 控制器的其它部分相互联系，如程序执行，内存操作，监督输入和设置输出。PLC 控制器拥有复杂的程序用于内存检查，以确保 PLC 内存不被损坏（内存检查是为了安全原因而作出的）。一般来说，CPU 单元多数用来检查 PLC 控制器本身，所以有可能出现的错误很早就会被发现。你可以简单地看任何 PLC 控制器,查看错误信号在发光二极管上的种种指示形式。 1.2内存 系统内存（今天主要是在 FLASH 技术上实现）用于一台 PLC 的过程控制系统。除了 这个操作系统它还包含用户程序将梯形图翻译成二进制的形式。 FLASH 存储器的内容仅在 用户程序改变下可以改变。PLC 控制器较早被用来代替闪存，EPROM 存储器代替了那些只能依靠紫外线灯等擦除内存并依靠程序员来编程的 FLASH 存储器。在 FLASH 技术的作用下这个过程被大大的缩短了。重组程序内存通过程序中的串行通讯用于应用程序开发。使用内存被划分成多个具有特殊功能的模块。存储器某些部分用来存储输入状态和输出状态。一个 输入信号的实际状态是用 1 或0 存储在一个特定的存储位。每一个输入信号和输出信号在内存里都有一个位与之相对应。内存的其他部分用来存储用户程序中使用的变量以及变量的内容。例如，定时器的值和计数器的值都将被存储在这部分内存里。 1.3PLC 控制器的编程 PLC 控制器可以通过计算机（常用的方式）进行编程，还可以通过手动编程器（控制台）编程。这实际上意味着如果你有需要的编程软件那么每个 PLC 控制器都可以通过计算机进行编程。今天的传输计算机是非常适合在工厂对 PLC 控制器进行编程的。这对工业有着非常重要的意义。一旦系统被刷新，重新读取正确的程序到 PLC 就很重要。还可以定期检查 PLC 中的程序是否改变了。这有助于避免在工厂车间发生危险状况（部分汽车制造商建立了通信网络，定期检查项目中的 PLC 控制器，以确保执行的程序是正确的）。
污水处理工业废水回用中英文对照外文翻译文献
(文档含英文原文和中文翻译) 中英文资料对照外文翻译 Catalytic strategies for industrial water re-use Abstract The use of catalytic processes in pollution abatement and resource recovery is widespread and of significant economic importance [R.J. Farrauto, C.H. Bartholomew, Fundamentals of Industrial Catalytic Processes, Blackie Academic and Professional,1997.]. For water recovery and re-use chemo-catalysis is only just starting to make an impact although bio-catalysis is well established [J.N. Horan, BiologicalWastewater Treatment Systems; Theory and Operation, Chichester, Wiley,
1990.]. This paper will discuss some of the principles behind developing chemo-catalytic processes for water re-use. Within this context oxidative catalytic chemistry has many opportunities to underpin the development of successful processes and many emerging technologies based on this chemistry can be considered . Keywords: COD removal; Catalytic oxidation; Industrial water treatment 1.Introduction Industrial water re-use in Europe has not yet started on the large scale. However, with potential long term changes in European weather and the need for more water abstraction from boreholes and rivers, the availability of water at low prices will become increasingly rare. As water prices rise there will come a point when technologies that exist now (or are being developed) will make water recycle and re-use a viable commercial operation. As that future approaches, it is worth stating the most important fact about wastewater improvement–avoid it completely if at all possible! It is best to consider water not as a naturally available cheap solvent but rather, difficult to purify, easily contaminated material that if allowed into the environment will permeate all parts of the biosphere. A pollutant is just a material in the wrong place and therefore design your process to keep the material where it should be –contained and safe. Avoidance and then minimisation are the two first steps in looking at any pollutant removal problem. Of course avoidance may not be an option on an existing plant where any changes may have large consequences for plant items if major flowsheet revision were required. Also avoidance may mean simply transferring the issue from the aqueous phase to the gas phase. There are advantages and disadvantages to both water and gas pollutant abatement. However, it must be remembered that gas phase organic pollutant removal (VOC combustion etc.,) is much more advanced than the equivalent water COD removal and therefore worth consideration [1]. Because these aspects cannot be over-emphasised，a third step would be to visit the first two steps again. Clean-up is expensive, recycle and re-use even if you have a cost effective process is still more capital equipment that will lower your return on assets and make the process less financially attractive. At present the best technology for water recycle is membrane based. This is the only technology that will produce a sufficiently clean permeate for chemical process use. However, the technology cannot be used in isolation and in many (all) cases will require filtration upstream and a technique for handling the downstream retentate containing the pollutants. Thus, hybrid technologies are required that together can handle the all aspects of the water improvement process[6,7,8]. Hence the general rules for wastewater improvement are: 1. Avoid if possible, consider all possible ways to minimise.