计量泵在实际中的应用—外文翻译

毕业设计(论文)外文翻译 译文：译文： 计量泵计量泵在实际在实际中的中的应用应用 essionmgr104&hid=117&bdata=Jmxhbmc9emgtY24mc2l0ZT1laG9zdC1saXZl#db=aph&AN=16 134947 计量技术应用于许多应用化学品和货物处理厂以及游泳池等的生产过程中。 Lutz-Jesco 股份有限公司的技术部门经理 Lucjan Gogolin 介绍了作为设备心脏的 计量泵的各种安装方式，并提供了必要的配件的合理选择使用的建议。 计量技术应用在化学品和货物的生产过程中， 以及在节能环保的制造业的应 用。 废水转换处理厂和游泳池作为计量技术的进一步用户。随着旨在实现优质节 能的计量技术水平的提高，专门设计计量装置和配件的需求在不断增加。 设计标准 隔膜计量泵（图 2）是非常常见的设计。其主要优点是防泄漏，耐磨损和空 运行的能力。 图 1 电机驱动隔膜计量泵，MEMDOS DX，电磁驱动隔膜计量泵 MAGDOS LT，柱塞计量泵，REKOS ZKR，柱塞计量泵 FEDOS DX（左到右） 。 Magdos 是一个电磁驱动隔膜计量泵。其电磁阀由电子设备和驱动器的线性 运动计量隔膜所控制。根据不同的型号，它可以从外部或内部被控制。外部输入 控制可以是来自一个水表或模拟信号的脉冲。内部控制则是另一种方式，在那里 可以按增量或线性方式调节冲程频率。每个冲程的容量设置的与冲程长度相适 应，因此，一转下来比率可以实现 1:1000。 Magdos 能够通过一个报警继电器远程评估显示供给箱的化学品的含量。根 据所需的服务， 可以给润湿端设置不同的材料。 PVC， PP， PVDF， 不锈钢， 1.4571 （316SS） 。配流阀的不同设计使泵更有效的吸入和排出：双球配流阀，对应于 水一样的介质， 弹簧球阀则更适用于 400 毫帕秒 （400 厘泊） 以上的粘度的介质。 特定的目的可用不同种类和尺寸的连接实现。 Minidos 和 Memdos 系列计量泵是电机驱动隔膜计量泵。 由单相或三相电动 机驱动一个单步蜗轮。传动电机的偏心旋转运动转换成柱塞的往复运动。这些泵 的线性容量调整，减少了柱塞行程。此外，电机的转速可以由一个可变频驱动装 置控制。 图 2隔膜计量泵的泵头。 更多选项 另一个选项是电子远程控制行程长度，在此，它可以选择一个三点一步或者 是通过接收的模拟信号进行控制的方式，Memdos DX 提供了一个独特的控制选 择。 它配备了完善的电子控制电机，输入的控制信号可以是来自水量计或从控制 器或 PLC 发出的模拟信号的联系密切的脉冲。该泵的控制也最多能够接收两个 一级输入指标。它通过一个干式触点可以输出供应罐的化学成分水平，以及其他 操作条件的消息。 图 3双隔膜计量泵的泵头 所有的更大的隔膜计量泵模型可以配备双隔膜系统（图 3） 。一个增加的计 量隔膜放置在泵驱动器和泵头之间的一个腔室中。 两个膜片之间的空间将充满已 抽离空气的中性分离液。当工作隔膜处于运动时，由于其液力测力环通过分离液 联结，计量隔膜将跟随。如果计量隔膜失效，由于磨损和撕裂，处理液无法离开 该系统，与分离液的混合改变了导电性。这种导电率的变化将被泄漏传感器检测 到，从而向远程控制站发送一个报警。 针对高压和高准确度而言,Fedos和Rekos以及kardos系列是优选的活塞计量 泵系列。活塞计量泵的高精度源于冲程长度和容量（图 4）之间的线性关系。这 些系列的泵被单相或三相电动机所驱动。 一个单步蜗轮可以降低电机的速度和产生冲程运动。Fedos DX 的活塞计量 泵具有一个功能集成在电机上的电子控制单元。 传入的控制信号以脉冲或模拟信 号的形式按比例转换为电机的运行时间和泵的流量。 图 4活塞计量泵的泵头。 控制功能 该泵的控制也能够接收到两个一级指标的输入。通过一个潜在的自由接触， 泵能够输出供应罐中相关化学品的含量以及其他工作条件的信息。Fedos 和 Rekos 计量泵的线性冲程长度和容量的调整是通过柱塞返回行程的限制来实现 的。 而考尔多什系列的行程长度调整则是通过改变曲柄轴的偏心度实现的。同样 在这里，这些泵（不包括 Fedos DX）的冲程长度和容量可以通过电子遥控器调 整，因此计量泵可以被用作一个闭环控制电路中的有源元件。 如果是在高压力下对磨蚀性或腐蚀性物质的计量， 隔膜和活塞计量泵的优势 可以结合起来。KMS 的活塞膜片系统可以确保一个高精度的定量给料任务（图 5）通过 KMS， Rekos 或考尔多什的齿轮被用作产生行程的驱动器。在这里， 柱塞推动一种无污染的液压介质，即甘油。由膜片从甘油中分离出一定剂量的化 学品。根据柱塞的冲程容积，一定量的甘油被移位。正是这一定量的甘油取代了 计量隔膜。另外还有内置气阀以防止出现泵过载的情况。 隔膜计量泵和活塞计量泵可以配备多个泵头。 他们的应用可能有以下几个原 因： 增加容量的需要。 将原本的最大容量分散在几个泵头当中，以此来满足高压方面的要求。 减小排放流量脉动。这是通过将不同的头设置不同的工作相位。 如果要求多种媒介被同时计量，则进行在不同相位上计量头相结合的一种 工作方式。 化学制品应按照一定的比例混合。不同尺寸的泵头可被应用，并且可以根 据每个泵头的冲程长度进行能力的微调。 图 5活塞式隔膜系统 图 6直插式 PDS 脉冲阻尼器 抑制脉动 由于膜片或活塞计量泵的往复式运动， 脉动是通过化学药物供料系统的排出 流体的过程中产生的。在其高峰时刻，单头摆动的工作计量泵转移的容量约为它 的标称容量的三倍。这意味着一台标称容量为 100 升/小时（26.4 加仑）的泵在 某一时刻的最大排放量为 314 升/小时（83 加仑） 。 安装了长吸气管或者小直径的排气管管道的将会导致压力峰值的增加。 设计 不当的管道系统可能会造成运作的干扰， 甚至损坏计量泵或整个化学药物供料系 统。但是一个完善的设计系统就能够避免这样的问题。 图 7隔膜计量泵输出图 图 6 对于此种问题的一个解决方案是脉动阻尼器 PDS 程序的运用。它是一 种平稳压力峰值到一个正常水平的有效手段。 脉冲阻尼器在排放冲程过程中存储 的一部分排出的流体，在吸入行程期间将会被释放到管道系统中。根据该系统的 设计，压力振荡大幅减少而且流量平稳。在管道中安装的 PDS 能够确保冲洗连 续不断。 安装的位置越靠近计量泵则能达到的效果越佳。 PDS 能够安装在计量泵 的两侧上吸入侧以及排出侧。 当施加了一个 PDS， 某些应用功能是可以实现的， 即一个吸入侧上的 PDS 能够提高泵的流体动力性，从而避免出现气蚀现象。 应用 PDS 的另一个机会是，帮助流量计功能的实现。大多数流量计不能在 不进行其他任何修改的情况下被用在计量泵的排出侧， 因为浮子向上移动或下降 的速度太快。 当一个脉冲阻尼器安装在短线或低压的应用上， 一个附加的装置 （节 流孔或针形阀）具有优化 PDS 运作的效果。如果是在需要被测定的高压环境的 应用中，则应该将 PDS 安装在计量泵的吸入侧的流量计上。 工作条件 隔膜阀是作为压力加载阀的较好的选择。由于其坚固，所以他们能够紧紧地 密封（向外） ，并且可以提供安全的操作。压力加载阀的大量应用主要有以下四 个原因： 计量泵智能压力负荷的产生 隔膜计量泵的容量依赖于压力。 如果在一个化学药物供料系统中水管中的压 力波动（例如 2 . 6 巴/ 29. 87 PSIG）时，它有安装一个压力加载阀的优势，隔 膜计量泵将提供一个背压总是高于计量系统中的预期的一致的最高压力。 在这里，压力加载阀应设置在 7 bar（101.5 PSIG） 。压力加载阀在工作时作 为一个防虹吸装置，并且不允许泵在任何低于 7bar（101.5 psig）的压力下排出 流量。因此泵必须始终产生一个为 7 巴（101.5 psig）的压力，从而即使很低的 泵容量，也能够使流体通过阀口。即使是在压力不断波动的系统，计量泵也总是 有一个不变的背压值7 巴（101.5 psig） ，并且按照它的设计准则进行工作。下 图说明了这些条件： （图 7） 所需的容量：100 升/小时（26.4 加仑） 系统压力波动 2 和 6 巴之间（29 至 87 psig） 。 容量将通过调整在 6 bar（87 psig）状况下的冲程长度从“a“到 100 升/小时 （26.4 加仑） 。若不是安装了压力加载阀，如果系统压力下降至 2 bar（29 psig） 的，计量泵排出的速度为 110 升/小时（29 加仑） ，而这相对来说实在是太大了。 因为安装的压力加载阀 压力预先设定为 7 巴（101.5 psig） ，泵的冲程长度将调 整为“b”的，所以，它的排放速度为 100 升/小时（26.4 gph） 。 如果行程长度设定保持在“a” ，它的排放速度只有 90 升/小时（23.8 加仑） 。 随着压力加载阀的调节形成的一定的阻力，在 7bar101.5 psig）下隔膜计量泵排 出的速度为 100 升/小时（26.4 加仑） 。然而，必须指出的是，压力负荷阀没有考 虑到泵系统的压力波动。 图 8“恒压计量”的流动图 1 压力维持和溢流阀2 压力表 3 注入点4 截止阀 5 脉冲阻尼器6 电动隔膜计量泵 7 过滤器8 截止阀 9 水箱 2避免虹吸作用 一些化学药物供料系统的设计在某种程度上允许计量泵通过潜力不受限制 的化学性流体。当出现这种所谓的“虹吸效应”时，即使供给箱处于注入点的上 方，计量泵也可能排出大气压力（即到罐或水箱） 。一种压力加载阀安装在排出 线的端部并且设置压力稍微高于完全装满的供给罐和注入点之间的静水压力， 从 而消除了虹吸现象。 3真空通道中的计量 计量泵供给真空管道或离心式泵的吸入管道的比所要求的化学药品多。 这里 也一样，运用真空使压力加载阀不能打开是有作用的。 ，只有当阀门开启时，由 于计量泵产生压力，过程液体才被计量。 4在循环管路中压力的平衡 循环管路技术在这个过程中用于向多个终端用户提供一种在相同的压力下 的媒介（图 8） 。将压力加载阀放置在循环管道的末端，从而保证的循环管路内 的介质处于相同压力下。 该泵所应具有的大小， 应以能够容纳足够的输出以满足一个完全开放系统的 需求为准。如果不是所有的终端都需要介质，则它的部分将通过阀门被释放到化 学罐中。 系统的布局对于采用使悬浮固体不断的运动以避免沉淀的解决方案是很 有帮助的。 原文：原文： Dosing pumps in practical applications essionmgr104&hid=117&bdata=Jmxhbmc9emgtY24mc2l0ZT1laG9zdC1saXZl#db=aph&AN=16 134947 Metering technology is applied in the production process of many applications from chemicals and goods to treatment plants and swimming pools. Lucjan Gogolin, manager technical department Lutz-Jesco GmbH, introduces the dosing pump in its variations as the heart of an installation and offers advice on the use of necessary and helpful accessories. Metering technology is applied in the production process of chemicals and goods as well as the economic and environmentally friendly application of those in the manufacturing industry. Water and waste water treatment plants as well as swimming pools are further users of metering technology. With the advancement of metering technology aiming for an improvement in quality and economy of processes, the demand for specifically designed metering devices and accessories increases. Design criteria A very common design of a dosing pump is the diaphragm dosing pump (Figure 2). Primary advantages are freedom from leakage, resistance to abrasive chemicals and dry run capabilities. Figure 1. Motor-driven diaphragm dosing pump MEMDOS DX, solenoid-driven diaphragm dosing pump MAGDOS LT, piston dosing pumps REKOS ZKR, piston dosing pump FEDOS DX (from the left to the right). The Magdos is a diaphragm dosing pump with a solenoid drive. The solenoid is controlled by electronics and drives with its linear movement a dosing diaphragm. Depending on the version, the pump can be controlled externally or internally. External control inputs may be pulses coming from a water meter or an analog signal. Operation with internal control is another option, where the stroke frequency can be adjusted incrementally or linearly. The capacity per stroke is set with the stroke length adjustment, thus a turn down ratio of 1:1000 can be achieved. The Magdos is able to evaluate the level of chemical in the supply tank with remote indication by means of an alarm relay. Depending on the required service, the wetted end can be provided in different materials: Figure 2. Diaphragm dosing head. PVC, PP, PVDF, and stainless steels, i.e. 1.4571 (316SS). Check valves of different designs for suction and discharge side make the pump more efficient: double ball check valves for water-like media and spring-loaded ball valves for viscosities from 400 mPas (400 cps) on. Different kinds and sizes of connections are available for specific purposes. Dosing pumps of the Minidos and Memdos series are motor driven diaphragm dosing pumps. A single or three phase electric motor drives a single step worm gear. The gear translates the motors rotating movement via an eccentric into a reciprocating movement of a plunger that moves the dosing diaphragm with a linear movement. The linear capacity adjustment at these pumps is achieved with a reduced plunger travel. Furthermore, the motor speed can be adjusted by means of a variable frequency drive. More options Another option is the electronic remote control of the stroke length. Here, it can be selected between either a three-point-step control or a control that receives an analog signal. A unique option of control is offered by the Memdos DX. It is equipped with a complete electronic control for the motor. Input control signals can be contact pulses, i.e. from a water meter, or analog signals Figure 3. Double-diaphragm dosing head from a controller or PLC. This pump control is also able to receive inputs from up to two level indicators. Via a dry contact the pump can output messages regarding the level of chemical in the supply tank as well as other operating conditions. All larger diaphragm dosing pump models can be equipped with a double diaphragm system (Figure 3). An additional dosing diaphragm is placed in a chamber between the pump drive and the dosing head. The space between both diaphragms will be filled airfree with a neutral separation liquid. When the working diaphragm is in motion, the dosing diaphragm will follow, due to its hydraulic link via the separation liquid. If the dosing diaphragm fails, due to wear and tear, no process liquid leaves the system. The chemical mixes with the separation liquid that changes its conductivity. This change of conductivity is detected by a leakage sensor that sends an alarm to a remote control station. Piston dosing pumps of the Fedos and Rekos as well as Kardos series are preferred, when pumping against high pressures and with high accuracy. The high accuracy of piston dosing pumps originates from a linear correlation between stroke length and capacity (Figure 4). Pumps of these series are driven by single or three phase electric motors.A one Figure 4. Piston dosing head. step worm gear reduces the motor speed and generates the stroke movement. The piston dosing pump Fedos DX features an integrated electronic control unit for its motor. Incoming control signals in the form of pulses or an analog signal are proportionally converted into motor operation time and pump capacity. Control features This pump control is also able to receive inputs from up to two level indicators. Via a potential free contact the pump can output messages regarding the level of chemical in the supply tank as well as other operating conditions. The linear stroke length and capacity adjustment at the Fedos and Rekos dosing pumps is achieved with a plunger return limitation. The stroke length adjustment at the Kardos series is realizied via the change of eccentricity of the crank shaft. The same here, stroke length and capacity at these pumps can be adjusted via electronic remote control (not Fedos DX), thus the dosing pumps can be used as active elements in a closed loop control circuit. If abrasive or aggressive media have to be metered against high pressures, the advantages of diaphragm and piston dosing pumps can be combined. The piston diaphragm system KMS ensures a high accuracy of this dosing task (Figure 5). With the KMS, the gear of a Rekos or Kardos is used as the drive for the stroke generation. Here, the plunger displaces a harmless hydraulic medium, i.e. glycerin. The chemical to be dosed is separated from the glycerin by a diaphragm. Depending on the stroke volume of the plunger a certain amount of glycerin is displaced. The dosing diaphragm is displaced by exactly this amount of glycerin. Internal valves secure the pump from an overload situation. Diaphragm dosing pumps and piston dosing pumps can be equipped with multiple dosing heads. Their app-lication may have several reasons: The capacity shall be increased. The maximum capacity shall be spread over several heads in order to meet highpressure requirements. The discharge pulsation is reduced. This is accomplished by the strokes of thedifferent heads being set out of phase. If various media shall be dosed in parallel, the dosing heads are combined in a way that they work in phase. Chemicals shall be mixed in a certain ratio. Dosing heads of different sizes can be applied, their capacities fine tuned via each individual stroke length adjustment. Figure 5. Piston-diaphragm system. Figure 6. Inline Pulsation Dampener PDS Dampening Of pulsations Due to the reciprocating character of diaphragm or piston dosing pumps, generated pulsations are carried through the chemical feed system by the discharged process fluid. At its peak a single head oscillating working dosing pump transfers approximately the threefold of its nominal capacity. That means a pump with a nominal capacity of 100 l/h (26.4 gph) discharges at a certain moment the maximum of 314 l/h (83 gph). Pressure spikes are increased when long suction and discharge lines or small pipe diameters are installed. Improperly designed pipe systems may contribute to disturbed operation and even to damaged dosing pumps or entire chemical feed systems. Such problems can be avoided by a well designed system. Figure 7. Output diagram of a diaphragm dosing pump. (Figure 6) One solution for this condition is the application of a pulsation dampener PDS. It is an effective means to smooth pressure spikes to a harmless level. The pulsation dampener stores a portion of the discharged fluid during the pumps discharge stroke that will be released back into the pipe system during the suction stroke. Depending on the system design, pressure oscillations are mostly reduced and the flow is leveled. Installation of the PDS in line with the pipe ensures constant flushing. Optimum results are achieved if installed close to the dosing pump. The installation of the PDS is possible on both sides of the dosing pump, on the suction as well as the discharge side. Certain applications are possible, when a PDS is applied. I.e. a PDS on the pumps suction side improves the fluid dynamics, thus cavitation is avoided. Another opportunity to apply a PDS is when a flow meter is implemented. Most flow meters can not be used on the discharge side of a dosing pump without additional modification, because the float would move up and down too fast. When a pulsation dampener is installed in short lines or pressureless applications, an additional device (orifice or needle valve) has to be incorporated in order to optimize the PDS operation. If the flow has to be measured in high pressure applications, the flow meter should be installed on the dosing pumps suction side with the PDS behind the flow meter. Operating conditions Diaphragm valves are the preferred option as pressure loading valves. They are tightly sealed (to the outside) and offer safe operation, due to their sturdy. Pressure loading valves are applied mainly for four reasons: 1. Generation of an artificial pressure load for dosing pumps The capacity of a diaphragm dosing pump is pressure dependant. If the pressure in a chemical feed system is fluctuating (i.e. 2 6 bar / 29 87 psig) in a potable water line, it is of advantage to install a pressure loading valve that will provide the diaphragm dosing pump with a consistent back pressure that is always higher than the highest expected pressure in the dosing system. Here the pressure loading valve should be set at 7 bar (101.5 psig). The pressure loading valve works as an anti-siphoning device and doesnt allow the pump to discharge at any pressure below 7 bar bar (101.5 psig). The pump must always generate a pressure of 7 bar (101.5 psig) in order to push the process fluid through the valve, even at low pump capacities. Even with fluctuating system pressure conditions the dosing pump always sees a consistant back pressure of 7 bar (101.5 psig) and will work according to its design criteria. The following diagram illustrates these conditions: (Figure 7) Required capacity: 100 l/h (26.4 gph) System pressure fluctuates between 2 and 6 bar (29 to 87 psig). The capacity will be adjusted via stroke length a to 100 l/h (26.4 gph) at 6 bar (87 psig). If there wasnt a pressure loading valve installed and the system pressure dropped down to 2 bar (29 psig), the dosing pump would discharge 110 l/h (29 gph), which is too much. With the installation of a pressure loading valve that is pre-set to a pressure of 7 bar (101.5 psig) the pumps stroke length has to be adjusted to bso that it discharges 100 l/h (26.4 gph). If the stroke length setting remained at a, it would dose only 90 l/h (23.8 gph). With the pressure loading valve adjusted to a certain resistance the diaphragm dosing pump will discharge 100 l/h (26.4 gph) against 7 bar (101.5 psig). However it must be remembered that the pump does not realize that the system pressure fluctuates down stream of the pressure loading valve. Figure 8. Flow diagram of “constant pressure metering” 1Pressure sustaining and relief valve2Pressure gauge 3To the injection p