ROTOFEED – BF  COAL INJECTION SYSTEM

旋转给料- 高炉喷煤系统

OVERVIEW概述

The coal injection system comprises two identical streams. This section describes stream 1. Stream 2 is identical.

喷煤系统包含两个相同的流程。这一节描述流程1，流程2是相同的

Each Rotofeed system consists of two dispensing vessels connected to a single injection pipeline. A volumetric feeder located at the outlet of each dispensing vessel discharges material into the injection pipeline at a controlled rate. Conveying air is introduced at the outlet from the feeder and the material is pneumatically transported through steel pipe work to lances located in the blast furnace tuyeres.

每个旋转给料系统有两个喷吹罐组成，连接一个单一的喷射管道。定容给料器位于每个喷吹罐出口，按照一定速率卸放物料进入喷射管道。喷吹空气从给料器出口引入，物料通过钢管气动喷吹冲入高炉的入口。

The operation of the two dispensing vessels is sequenced so that one vessel is discharging coal into the injection pipeline while the other is re-filling. In this way a continuous feed of coal is maintain to the blast furnace.

两个喷吹罐的操作是顺序进行的，一个罐卸放煤进入喷射管道同时另一个罐装填物料。这样保持了进入高炉的煤是持续的。

During the refill sequence the pressure in the dispensing vessel is vented prior to opening the inlet valves. Coal is then discharged from the silo by gravity with the assistance of fluidisation. When the vessel has filled it is re-pressurised with nitrogen. This operating sequence is described in detail in the section titled “Rotofeed Operating Sequence”.

在装填过程开始之前排气阀打开，喷吹罐的压力释放。粉煤在重力作用下从料仓流下。当罐被加满再重新氮加压。这个操作过程在“旋转给料操作过程”章节中有详细描述。

The Rotofeed volumetric feeder is driven through a gearbox by a standard AC induction motor. The electrical supply to the motor is from an AC variable frequency drive, which enables the feeder speed and hence material discharge rate to be controlled. A proximity sensor mounted adjacent to lobes on the feeder drive shaft will provide pulses to the control system enabling the feeder speed to be calculated. These pulses are also used in conjunction with the vessel contents weight to determine the feeder output characteristic and hence the speed required to achieve the desired injection rate. The Operator may adjust the injection rate at any time and the feeder speed will change appropriately.

旋转定容给料器的驱动是通过一个标准的交流感应电机带动的变速箱进行的。电机的电力供应来源于一个交流变频驱动器：这使得FEEDER转速和物料的流速能够控制。一接近传感器安装于相近的FEEDER驱动轴的凸出部提供脉冲，控制系统使FEEDER的转速可以计算。这些脉冲也于罐内容重一起用于确定FEEDER的输出特性，因此需要的速度才能实现理想的喷射速度。操作者可以随时调整喷射速度，FEEDER的速度将变为合适的速度。

Nitrogen fluidisation is operated continuously while the feeder is working. This has two purposes. The first is to fluidising the coal so that it flows easily into the feeder without bridging. The second purpose is to replaced the volume of coal discharged with nitrogen. In this way the back-flow of conveying air is prevented and the inert conditions within the dispensing vessel is maintained at all times.

当FEEDER工作时氮气流化过程是连续的。这有两个目的。首先是使煤粉流化使它容易流进FEEDER没有架拱，第二个目的是取代煤排放的氮气。这样在任何时间防止喷吹空气回流使喷吹罐内保持惰性环境。

Each dispensing vessel is mounted on load cells to allow the control system to monitor the contents weight.每个喷吹罐装有称重单元使控制系统监测罐内重量。

During the operation of the Rotofeed the control system records the contents weight in the dispensing vessel at two times each cycle. The first is after the dispensing vessel has filled. The second is after the dispensing vessel has finished discharging. Between the two weight measurements the control system will record the number of feeder revolution made. The amount of material discharged will be determined by subtracting the “empty” weight from the “full” weight. This will then be divided by the number of feeder revolutions made over the same period to obtain a “feeder calibration factor”. Numerically this equals the weight of coal discharged per revolution of the feeder. It is used by the control system to set the feeder speed required to obtain the desired injection rate set by the Operator。

在旋转给料控制系统的运行过程中，每个循环记录两次喷吹罐容重。第一次在喷吹罐装满后，第二次是在罐卸放完成后。在两次测量重量间控制系统将记录给料器的旋转数据。物料排放的数量将被确定通过从“满”位重量中减掉“空”位的重量。给料器的旋转数据在同一期间内将被分离出来获得一“给料器校准数据”。这数据相当于每个给料器转速下的煤粉卸放量，操作者把它用于控制系统来设置给料器需要的转速以获得理想的喷射速率。

As part of the operating cycle pressure is periodically vented from each dispensing vessel. This will be routed to the prepared coal silo which must be equipped with a suitably sized filter or other vent to prevent it being pressurised.

作为一运行循环周期压力从喷吹罐内定期排出，这些将按确定的管路排放到粉煤仓，粉煤仓必须配备合适的除尘器或其它的通风口以释放压力。

SYSTEM AT REST

系统间歇状态

When the Rotofeed is stopped and at rest the status of the valves will be as follows:

当ROTOFEED停止期间各阀的状态如下：

* Note: The Dome Valve incorporates an inflating seal. In the event of the loss of sealing gas pressure the valve will not be sealed.

          注：圆顶阀集成一充气密封。如果发生密封气压损失阀将不会密封。

* Note: The Dome Valve incorporates an inflating seal. In the event of the loss of sealing gas pressure the valve will not be sealed.

注：圆顶阀集成了一充气密封。如果发生密封气体压力损失阀将不会密封。

** Note: The secondary line air valve will be open unless the pressure in the injection pipeline (1PT06) reaches a pre-set value of 2.65 barg. The valve will then close. It would re-open again when the pressure has fallen below 2.45 barg.

          注：二级气阀将被打开除非喷射管内压力达到设定的2.65bar.该阀将关闭。当压力低于2.45bar阀将再次重新打开。

Normally, when the Rotofeed is working the pressure in the injection pipeline will be below the set value and the valve will be open. When the system is stopped and the Conveying Valves at the Outlet from the 14-Way Splitter are all closed, PurgeValve are all opened the injection pipeline will pressurise up to and remain at the pre-set pressure. In this way there will always be a positive pressure gradient towards the furnace to prevent a back-flow of hot gases.

          通常的：当Rotofeed工作时喷射管内的压力将低于设定的压力值，输送阀将被打开。当系统停止且从分配器出来的输送阀关闭清吹阀打开时、喷射管的压力将上升并保持设定的压力。这样对炉子将总是有一个正压以防止回流的热气体。

*** Note: The Conveying Valves at the Outlet from the 14-Way Splitter will fail to open the air purge towards the furnace to provide cooling of the lances.

输送阀如果不能开启，清吹阀将朝向炉子喷空气来为喷枪提供冷却.