菠菜

隧道窑还原铁生产线工艺

Tunnel Kiln Reducing Tank Process For Sponge Iron Project with Annual Output of 100,000 Tons

5.3 Introduction

    工艺简介

5.3.1 Raw material preparation

        原料制备

5.3.1.1  Iron ore powder:

             铁矿粉：

The iron ore powder to be dry and then to be conveyed into high stock bin for use.

铁矿粉烘干，经斗式提升机入高位料仓料仓备用。

5.3.1.2  Desulfurizer

              脱硫剂

To ensure that no CaO in particle coke, size of desulfurizier to be less than 1mm.  The desulfurizer is dosed as per 120Kg per ton of coal.

为了保证颗粒煤焦中不含CaO,脱硫剂加工到小于1mm。脱硫剂按每吨煤120Kg加入。

5.3.1.3  Reductant

              还原剂

The reductant has a size of less than 5mm, and the processing capacity of equipment is  10t/h. Before the reductant is broken and dried, the desulfurizer is dosed into  as per the proportion. Then the dried mixture of desulfurizer and reductant is conveyed  into high stock bin for use.

 还原剂加工粒度粒度小于5mm,设备加工能力10t/h,还原剂破碎烘干前，脱硫剂按工艺要求比例加入,经斗式提升机入高位料仓料仓备用。

The moisture content of all dried material is below 3% , the heat source of the dryer is  natural gas. The exhaust gas is discharged into the air through the chimney with the  induced draft fan subject to dust removal with the dust remover.

烘干后所有原材料的含水率控制在3%以下，再烘干机的热源为天然气。烟气经除尘器除尘后经引风机由烟筒排入空气中。

Raw material preparation       原材料准备

5.3.2  Kiln equipment

       窑炉设备

     The diameter of SiC tank is designed as φ390mm, and tank height 1,750mm, and the thickness of lower layer of coal powder is 40mm and the thickness of upper one 50mm.

     碳化硅罐直径设计为φ390，罐高1750，下层煤粉厚度40mm，上层煤粉厚度50mm.

              5.3.2.1       Design Parameters                     设计参数

 Kiln equipment         窑设备图片

5.3.2.3 Foundation of the tunnel kiln

          隧道窑基础

Reinforcing bars of the tunnel kiln foundation is φ12mm screw-thread steel

隧道窑基础配筋φ12mm螺纹钢。

The thickness of all reinforced bar protection layers is 60mm.

钢筋保护层厚度均为60mm。

The cushion is 100mm plain concrete, and the foundation is poured with C25 commercial concrete.

垫层为100mm素混凝土，基础为C25商品混凝土浇筑。

The width of based expansion joint is 20mm.

基础膨胀缝宽20mm。

The 33kg/m track is used for the one inside the kiln, with the allowable wheel pressure of  10T and required soil bearing capacity of ≥20T/m2.

窑内轨道采用33kg/m轨道，允许轮压10T，要求地耐力≥20T/㎡。

The 24kg/m track is used for the one outside the kiln, with the allowable wheel pressure of 6T and the required soil bearing capacity ≥10T/m2.

窑外轨道采用24kg/m轨道，允许轮压6T。要求地耐力≥10T/㎡。

5.3.2.4 The structure of refractory material of the tunnel kiln

             隧道窑耐火材料结构

      The vault structure is adopted for tunnel kilns.

      隧道窑采用拱顶结构。

      The refractory material of kiln body is seleced by temperature section.

      窑体耐火材料分温度区段进行选材。

      Expansion joints shall be reserved according to the expansion rate of materials.

      伸缩缝应按原材料的膨胀率保留。

The tunnel kiln should have room for heat expansion and cold contraction when  temperature rising and dropping of tunnel kilns, avoiding deforming.

       隧道窑应具有热膨胀和冷缩的空间隧道窑温度上升，下降，避免变形。

      SiC bricks are used surrounding the flame outlet of the burner.

      燃烧器火焰出口周围采用碳化硅砖。

5.3.2.5 Kiln car

         窑车

Steel structure is welding with H-steel and U-steel, supplemented with the 75 angle steel.  3mm steel plate is used as lining, 6mm steel plate is used as sand seal knife  and 30 angle steel is used to enclose refractory material of the kiln car.

窑车钢结构由22#工字钢和槽钢焊接而成，75角钢补充。3mm钢板做窑车衬面，          6mm钢板做砂封刀，30角钢围住窑车耐火材料。

       50 U-steel and 6 x 30 flat iron are arranged in front and back steel structures.

       50槽钢与6×30扁铁在窑车前后钢结构上布置。

      Abnormal three-grade high-aluminum bricks are used as the periphery of kiln cars, and large blocks three-grade high-aluminum face bricks are used as platform  pavement of kiln cars, allowing kiln cars to be stable.

       窑车采用异型三级高铝砖做四周，大块三级高铝面砖做窑车台面，窑车稳固。

       Bottom use higher density and light clay bricks to preserve the heat.

        底层砌筑较高密度轻质粘土砖保温。

Kiln car 窑车

5.3.2.6 Electric equipment of tunnel kilns

        隧道窑电器

 The mode of intelligent instrument + PLC + computer control is adopted for this kiln  to control the temperature and pressure system.

   该窑炉采用智能仪表+PLC+计算机控制模式进行温度、压力制度的控制。

Temperature display: The intelligent temperature displayer combined with           temperature thermocouple is used to display temperatures of each point in the kiln.

   温度显示：采用智能温度显示仪与测温热电偶相结合，对窑炉各点温度进行显示。

  Pressure display: 3sets ±100Pa pressure transmitters combined with intelligent           instrument are used for measuring the pressure inside the kiln. 2sets ±100Pa           pressure transmitters combined with intelligent instrument are used for displaying  the pressure beneath cars.

   压力显示： 窑内压力采用3台±100Pa压力变送器与智能仪表相结合，对窑内气压进行显示。车下压力采用2台±100Pa压力变送器与智能仪表相结合，对车下压力进行显示

  Power control: The frequency converter is used to control the power of kiln exhaust  gas and combustion-supporting fans.

  动力控制：窑炉排烟和助燃风机动力采用变频器进行变频控制。

Computer control: All temperature and pressure can be displayed in the computer.         

计算机控制：温度压力可都在计算机显示。

 Computer monitoring system.

 计算机监视系统。

5.3.3          Loading work section 装料工段

       5.3.3.1   Load the mould 放模

     The time of loading the mould shall not exceed 20 minutes.

      放模时间不超过20分钟。

   5.3.3.2           Load reductant for one time  一次装还原剂

Load into 60% - 70% of the total amount of reductant for the first time, and the

40mm of bottoming thickness shall be guaranteed.

第一次装入总量60%—70%的还原剂，并保证铺底厚度40mm；

The time of loading reductant for one time shall not exceed 20 minutes.

一次装还原剂时间不超过20分钟。

5.3.3.3 Load iron ore powder 装铁矿粉

Check after loading and conduct manual paving for uneven loading of tanks;

装料完毕检查装料情况，对于装料不匀的料罐，人工进行铺平。

The time of loading iron ore powder shall not exceed 20 minutes.

装铁矿粉时间不超过20分钟。

5.3.3.4    Secondary loading of reductant

            二次装还原剂

Load reductant 50mm, after loading, check the condition of loading.

再次装还原剂50cm，装料完毕检查装料情况；

The time of secondary loading of reductant shall not exceed 20 minutes.

二次装还原剂时间不超过20分钟。

5.3.3.5 Unload the mould 起模具

During the process of unloading the moulds, watch if there is any phenomenon of tank sticking at any time. No mistake, material trolley is transported to restoration  work section.

启模的过程，随时注意有无卡罐的现象，确认无误的料车运至还原工段。

5.3.4 Restoration work section

        还原工段

5.3.4.1 Kiln car entering  进窑车

After loading material, kiln car is dragged to the car-entering position of tunnel kiln head, start car pusher to push kiln car into kiln.

装料完毕的窑车，拖至隧道窑窑头的进车位置，启动顶车机将窑车顶进窑内。

5.3.4.2 Reduction  还原

After entering tunnel kiln, kiln car passes through three phases of pre-heating, reduction, and cooling in tunnel kiln, respectively, and leave out of the kiln within regulated time.

进入隧道窑内的窑车，在隧道窑内分别经过预热、还原、冷却三个阶段，在定时间内出窑。

5.3.4.3 Kiln car leaving out of the kiln  窑车出窑

After the completion of reduction, kiln car goes out from kiln tail as required, and be transported back to returning lane.

还原完毕之后的窑车，按照规定由窑尾出车，运至回车道。

Reduction System

还原系统图

5.3.5 Unloading work section

         卸料工段

5.3.5.1 Primary ash suction

          一次吸灰

After reduction, kiln car is transported to the working position of primary ash suction, suck the waste ash. Six ash suction heads on ash collecting car, one row of tanks on kiln car is sucked every time; For each car, the completion time of ash suction shall not exceed 30 minutes;

还原完毕的窑车，运至一次吸灰工位，吸走废灰。吸灰车上有六个吸灰头，每次吸窑车一排罐。每部车吸灰完成时间不超过30分钟；

Primary ash suction            一次吸灰图

5.3.5.2 Unloading of sponge iron

         卸海绵铁

After primary ash suction, material car is transported to the work position of unloading; take out sponge iron from SiC tank in order and put into receiving machine. Mechanical hand unloads one row of six columnar sponge irons from kiln car each time. For each car,the completion time of unloading shall not exceed 40 minutes;

一次吸灰完毕的料车，运至卸海绵铁工位，将SiC罐内海绵铁依次提出，并放进海绵铁接料机内；海绵铁机械手每次从窑车上卸一排，即6个柱状海绵铁；每部车卸料完成时间不超过40分钟；

Unloading work section

卸料区图

Unloading work section       卸载工作段

5.3.5.3 Secondary ash suction

         二次吸灰

After unloading sponge iron, kiln car is transported to the work position of secondary ash suction; suck away all rest waste ash in SiC tank. Clean clogging matters in SiC tank, put straight SiC tank, replac damaged fire-resistant material of car; after inspection, empty tanks are transported to loading work position to continue the operation of the  next circulation.

卸海绵铁完毕的窑车，运至二次吸灰工位，将SiC罐内剩余废灰全部吸走，并将SiC罐内结瘤物清理干净，更换台车损坏的耐火材料，检查完毕的空罐运车运至装料工位，进行下一个循环的操作。

There are six ash suction heads on ash collecting car, one row of tanks on kiln car is sucked  every time;

吸灰车上有六个吸灰头，每次吸窑车一排罐；

For each car, the completion time of ash suction shall not exceed 30 minutes;

对于每一辆车，吸灰的完成时间不超过30分钟；

Secondary ash suction                         二次吸灰图

5.3.5.4 Ash suction grading dust collection

                 吸灰分级除尘

For coal ash that passing through iron powder reduction, its particle material still has about 30% C content; for the coal ash sucked from SiC tank, firstly, particle ash is graded out through gravity dust collection, particle ash can be recycled and reused, CaO and fine  are collected by bag-type dust collector and discharged.

应经还原过铁粉的煤灰，颗粒料还有30%左右的含C量，从碳化硅罐中吸出的煤灰，先经过重力除尘，将颗粒灰分级出来，颗粒灰可以回收再利用，CaO和细灰则在布袋除尘器收集后排出。

The dust content of gas discharged from chimney is less than 50mg/m³.

烟筒排出的气体含尘量小于50mg/m³。

Ash suction grading dust collection          除尘系统图

5.3.5 Work section of material receiving and briquetting pressuring

        接料和压块工段

Restored columnar sponge iron in order, then conduct breaking one by one, final product, direct reduced iron cold-briquetting, i.e., CBI.

将还原好的柱状空心海绵铁按顺序放好，然后一根根进行破碎进行，最终产品直接还原铁冷压块即CBI。

Sponge irons are taken out from SiC tank by material-unloading mechanical hand, after reaching the position of material receiving, they are caught by material-receiving mechanicalhand, placed on a track, and arranged in line; columnar hollow sponge irons are sent to multi-roll conveyor piece by piece, which convey them into crusher for breaking.

卸料机械手从碳化硅罐中提出的海绵铁，到达接料位置后，由接料机械手接住，放在轨道上，排成一排，由拨管机构将柱状空心海绵铁一根根送到多辊输送机上，由多辊输送机送进切破机中破碎。

Material  Receiving        接料系统图

As sponge iron has good tenacity, it is not suitable for extrusion type crushing . We designed a crusher for columnar sponge iron. Sponge iron is cut into 100mm blocks.

海绵铁韧性好，不适后挤压破碎，我们设计了针对柱状海绵铁的切破机，由切刀将切成100mm块状。

After being broken, sponge iron is screened out material under 10mm, the screened  material enters magnetic separator to separate out coal ash without magnetism. The blocks more than 10mm enter hammer-crusher for breaking into small blocks less than 10mm, which are sent into stock bin along with the sponge iron separated by magnetic separation for the preparation of briquetting.

柱状空心海绵铁经切坡机破碎后由筛分机筛出10mm以下料，筛下料进入磁选机，选出不含磁性的煤灰，大于10mm的块进入锤破机中破碎，破碎成小于10mm的小块，连同磁选出的海绵铁一同输送到料仓中，准备压块。

Magnetic  Separation           磁选系统图

Briquetting Pressuring

压块图

The project adopts 8 briquetting machines.

本项目选用8台压块机