This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
RECOMMENDATIONSubject: Cement Kiln
Revision No.: 01 Date Issued: 22/02/17 Page: 1 of 19
欧西曼是一家致力于向全球客户提供耐火材料和相关服务的专业公司。公司总部位于中国天津市滨海新区海泰高新区,距离天津港仅60公里。 欧西曼耐材主要服务于四大工业领域:钢铁工业;水泥回转窑;有色冶炼炉;玻璃窑。 OSYMEN is a specialized Refractories manufacturer and related services for global customers. Headquarter in Binhai Hi‐Tech Industry Park, Tianjin, China. OSYMEN mainly serves 4 industrial areas:
1) Steel Industry 2) Non‐ferrous Metal Furnaces 3) Cement Rotary Kilns 4) Glass Furnaces
Specialized in the production of magnesia refractories, it covers an area of 200000 square meters, with 600 staff including 80 engineers, 15 staff are senior engineers.
The total investment is 350 million RMB. There are now 3 high temperature tunnel kilns, with 90,000 tons burnt bricks capacity, unburnt bricks 40,000 tons and unshaped products 20,000 tons.
砖,高铝砖,红柱石砖,莫来石砖,CDQ炉砖,硅砖,连铸耐火产品等领先的耐火材料制造商之一。 Specialized in the production of Al‐Si series refractories, it has strong research and development capability, R&D center is full responsible for test, research and product
innovation, with 13 Senior Engineers, 69 Engineers and 29 assistant Engineers. Enables itself to be one of the leading refractory manufacturers for supplying Clay bricks,
High Alumina bricks, Andalusite bricks, Mullite bricks, bricks for CDQ Furnace, Silica bricks, Con‐casting refractory products, and so on.
浇铸料等,广泛应用于玻璃、石化、冶金、建材等行业。拥有胸墙复合保温砖、蓄热室用筒子砖、旋转管、匀料筒、料棒、坩埚等特色产品。 Specialized in the production of Fused Cast Refractories, 430 employees with 46700 square meters areas, and the annual casting capacity can reach to 20,000 tons.
Started working with Japanese Management Company to carry out TPS management system in the company. At this moment, It has got two automatic production lines.
The material batch feeding process and melting process are under computer digitized management. And has 42 sets cutting and grinding equipments, 8 sets specialized assembling equipments and 3 sets assembling platform of 2050 square meters, which can enable to assembling 1000 tons float glass furnace. In addition, imported some
advanced test and analysis equipments, such as the Rader inner detect equipments can test the shrinkage of blocks, the X‐RAY Fluorescence analyzer can give us the
accurate chemical analysis within 15 minutes.
RECOMMENDATIONSubject: Cement Kiln
Revision No.: 01 Date Issued: 22/02/17 Page: 3 of 19
Made of magnesia and synthetic spinel, processed by high temperature sintering. RMAS Bricks are most extensively, most mature
and most economical bricks used in the world for cement rotary kiln transition zone under any condition.
It has many characteristics such as excellent resistance to thermal shock, thermal load damage, and chemical corrosion, overheat fatigue, oxidation
reduction and wearing as well as high temperature mechanical flexibility. However, it is not good in clinker coating and high in thermal conductivity. So, we
recommend it as the first choice for rotary kiln transition zone bricks.
Made of magnesite and hercynite, RMFS processed by high temperature sintering. It was widely used both in burning and transition
zone. It can reduce the standby inventory and thus lower cost. It is good in clinker coating and resistance to thermal shock. Clinker coating can form rapidly
and stably. The coating doesn’t fall easily and thus it reduce the kiln proper temperature. It is excellent in resistance to chemical corrosion, overheat damage,
oxidation reduction without conditions such as alkali cracking or loosening. It is good in resistance to thermal load fatigue, especially in high temperature
mechanical flexibility and wearing resistance. It is the best choice to be used at kiln tire areas.
RMNS is made primarily of magnesite under medium to high temperature burning with addition of some alumina, manganese oxide. It can be used
both in burning and transition zones in rotary kiln instead of magnesia chrome brick.
It works well in cement rotary kiln in terms of clinker coating, with high in thermal shock resistance. It is excellent in resistance to chemical corrosion, overheat damage
and wearing as well as high temperature mechanical flexibility. It is good in resistance to thermal load fatigue, especially suitable for frequent temperature change.
Made of dead burned magnesia and chromites, processed by high temperature sintering. RMCR are most extensively used in the world. They are
used at burning zone and transition zone of cement kilns. They are adaptive to any conditions and economical. With properties of good clinker coating,sound thermal
shock resistance, good heat load weariness resistance,good chemical corrosion resistance,good thermal fatigue resistance, good oxidation-reduction resistance.
Disadvantages are hazardous to environment. OSYMEN therefore developed low chrome magnesia chrome bricks or chrome free products as alternatives to traditional
RMCR products.
Please note:All OSYMEN chrome containing products has been treated with hazard free technologies, and try our best to reduce the potential harm to the environment.
All our present product meet the standard of US environment protection. Customer can use at ease.
Made of Alumina Corundum and Silicon Carbide,processed by medium temperature sintering. RASM Bricks are recently promoted
rapidly in China as new products at transition zone.
It is excellent in resistance to thermal shock, thermal load fatigue, high temperature mechanical flexibility, and wearing as well as oxidation
reduction. With its low thermal conductivity factor, it can reduce the drum temperature and prevent the kiln drum and tire from expansion and good in insulation and save
energy. Because it is low in bulk density, it effectively reduce the load on drum, tire and power system.
1. Chemical corrosion: component such as alkali sulfate and chloride volatile, condense, again and again; penetration of ingredient such as C2S, C3A and
C4AF in the cement clinker cause structural peel off.
2. Thermal stress: As the gas temperature is higher than that of material in the kiln, the lining surface temperature change will be 150-250oC when the kiln
rotates. The refractory will suffer from cycle impact.
3. Mechanical stress: radial and axial mechanical stress is generated on the lining when the kiln rotate due to the brick construction. The lining is also
rubbed by the calcinated material.
4. High temperature: though it is generally not a major factor of damage. Regional overheat will lead to rapid damage of the kiln lining.
化学侵蚀损毁,约占损毁的 27%
About 27% due to chemical corrosion 机械应力损毁,约占损毁的 37
about 37% due to mechanical
stress
热应力损毁,约占损毁的 36%
about 36% due to thermal stress
回转窑各段带耐材损毁原因和要求/
Reason of damage and demand of refractory for each zone of rotary kiln 段带 Zone
损毁原因 Reason of damage
对耐材的要求 Demand on refractory
分解带 Calcining zone
原料磨损; 热剥落和结构剥落; 耐火砖脱落。
Raw material abrasion; Thermal and structure peel off; Refractory brick fall off.
耐磨性 耐热剥落和结构剥落性; 低热膨胀性。
Abrasion resistance; Resistance to thermal and structure peel off; Low thermal expansion
过渡带 Transition zone
热剥落; 热面损蚀; 结构剥落。
Thermal peel off; Hot face corrosion; Structural peel off.
抗热剥落; 低气孔率和低透气性; 耐结构剥落性。
Resistance to thermal peel off; Low apparent porosity and permeability; Resistance to structural peel off.
烧成带 Burning zone
与熟料化学反应; 外来成分渗入,产生结构剥落; 高温引起的侵蚀。
Reaction with clinker; Structure peel off due to foreign material penetration; Corrosion due to high temperature.
抗侵蚀性; 抗结构剥落性; 挂窑皮附着性。
Corrosion resistance; Resistance to structural peel off; Resistance to clinker coating adhesiveness.
冷却带 Cooling zone
熟料磨损; 温度变化引起的热剥落; 出料口周围的机械剥落。
Abrasion by clinker; Thermal peel off due to temperature change; Mechanical peel off around outler.
耐磨性; 耐热剥落性; 应力释放能力
Abrasion resistance; Resistance to thermal peel off; Stress release capability.
RECOMMENDATIONSubject: Cement Kiln
Revision No.: 01 Date Issued: 22/02/17 Page: 9 of 19
1. Installation: kiln shell welding joints should be fully welded and polished, kiln inside surface should be cleaned and dried. Measure and mark the kiln
axis. Align the kiln bricks along the kiln axis. Proceed on either directions. Install the bricks up to the kiln center. Continue installation to form brick rings
that are perpendicular to the welding joint. Make sure the brick ring gaps are closed. Close bricks should not be used contunually one after another.
Basic bricks expansion ring gap should be evenly retained (2mm ring, basic bricks attached with card boards can alright), axial enpansion gas is not
necessary. Alumisic bricks, high alumina bricks and light bricks do not need expansion gap. Mortar should be spread evenly, limited thickness <1.5mm.
when steel plates are used during installation, they should be evenly distributed (do not put 2 plates in the same gap). Big side of the brick should be
closed attached to the surface of the kiln, to prevent loosening or deforming. Horizontal gap must be strictly directed to the axis of the kiln. Any irregular
welding joints and deformed part of the kiln must be closed by mortar so as to keep other brick brick rings parallel. New bricks and old bricks must be
tightly attached. Because of the eneven surfaces of old bricks, trimming bricks is necessary, trimming old bricks length should be more than 80mm to
ensure tight attachment of old and new bricks.
2. Notes:
a> Only 1 steel plate can be inserted between lining and stopping ring.
b> Do not trim or remodel bricks at kiln tire area.
c> Do not use different typs of basic bricks at burning zone.
d> Do not use steel hammer during installation, use wooden hammer or rubber hammer.
3. Installation problems: a) dislocation. b) inclination. c) uneven mortar gaps. d) sloping. e) decentralization. f) double gaps. g) penetration gaps. h) open
Heating up of the kiln is indispensable procedure during cement production. It can be divided as three stages:
1) moisture removal and draining, the kiln end temperature is at between to 200 oC.
2) linear expansion of brick lining, the kiln end temperature is between 200-950 oC.
3) liquid pahse generation, the kiln end temperature is between 950-1100 oC.
During heating up, the kiln will be rotated. The rotation speed is increased slowly based on the lining temperature. Practically, between 300-600 oC, 1/3 cycle
is rotated per every 30 min.
between 600-900 oC, 1/3 cycle is rotated per every 15 min.
between 900-1200 oC the kiln should be rotated continuously and slowly, at about 0.8 cycle per min.
when kiln end temperature is at 950 oC (the temperature at burning zong will be 1450 oC), feeding for coating can be started. The feeding quantity is about 70%
of that for normal production. The rotation speed is at 2.4-2.6 cycles per min. the temperature should be kept stable. After three shifts (24hours), the coating
is basically full and stable. Normal feeding can started at 3.2-3.5cycles per min.
RECOMMENDATIONSubject: Cement Kiln
Revision No.: 01 Date Issued: 22/02/17 Page: 11 of 19
General recommendation: Use VDZ shapes for basic lining and ISO shapes for alumina bricks
普遍性的建议:碱性砖适用 VDZ 砖型砌筑,高铝砖适用 ISO 砖型。
Note: for very large diameter kiln (Φ>5.6m) ISO shapes are recommended also for basic bricks, due to the greater taper, which increases lining
stability during kiln start-up.
注意: 对于直径很大的窑(Φ>5.6m),建议碱性砖也是用 ISO 砖型,因为 ISO 砖型的锥角更大,在开窑期间可以增加砖衬稳定性。
VDZ linings have approx. 30% more brick joints which provides increased flexibility and thermal shock resistance to the rings.
使用 VDZ 砖型衬砌,砖缝月多了 30%, 这样砖环的柔性和抗热震性能更好。
Alumina bricks are usually layed with mortar to adjust greater dimensional tolerance of alumina brick.
高铝砖通常要用火泥湿砌来调整其过大的尺寸公差。
Cardboards (basic bricks) 纸板(碱性砖) Basic bricks have cardboard attached to compensate for higher thermal expansion.
碱性砖贴有纸板,用于补偿过高的热膨胀。
Attached on axial joint (thickness 1.5mm). Burn-out of cardboard is faster than thermal expansion of bricks, so great care must be taken when turning the kiln
Attached on radial joint of each brick (thickness 0.7mm). start to soften at approx. 600oC and to oxidise at >1000oC thus forming a ceramic bond between
bricks. Must not be confounded with key shims which are driven in to tighten the rings.
Fireclay and alumina bricks are not susceptible to hydration and can be stored indefinitely.
粘土砖和高铝砖不会水化,储存期是无限的
Mortar should not be stored at customer’s warehouse for more than 12 months.
火泥在仓库中储存不应超过 12 个月
Magnesia bricks are susceptible to hydrate, especially under tropical conditions and when made from high purity, synthetic magnesia. Normally, if the pallets
not to be opened, the bricks can be kept in warehouse one year, no problem for using.
Magnesia bricks which have become wet must be stacked openly and ventilated at ambient air temperatures until dried cmpletely. Do not use hot air, do not
expose wet bricks to the heat radiated from the kiln shell. After drying, check bricks carefully for radial cracks.
如果镁质砖变湿,必须使其暴露于空气中堆放,并在环境气温中通风干燥直至干透。
New lining sections which have become wet must be removed and replaced by dry bricks.
如果新砌的砖衬变湿,必须拆下换上干燥的砖。
Wet bricks must be removed! 湿砖必须换掉!
RECOMMENDATIONSubject: Cement Kiln
Revision No.: 01 Date Issued: 22/02/17 Page: 14 of 19