Rotary cement

FIG. 23-43 Reactors for solids, (a) Temperature profiles in a rotary cement lain, (h) A multiple hearth reactor, (c) Vertical lain for lime burning, 55 ton/d. (d) Five-stage fluidized bed lime burner, 4 by 14 m, 100 ton/d. (e) A fluidized bed for roasting iron sulfides. (/) Conditions in a vertical moving bed (blast furnace) for reduction of iron oxides, (g) A mechanical salt cake furnace. To convert ton/d to kg/h, multiply by 907. 

Uses. Used mineral-hased crankcase oil is mixed with other oils to produce cutting oils or other lubricating oils. It is incinerated for energy in oil burners in homes, industrial steam boilers, municipal incinerators, and rotary cement kilns. It is also used in asphalt production. 

Figure 1730. Kilns and hearth furnaces Walas, 1959). (a) Temperature profiles in a rotary cement kiln, (b) Space velocities in rotary kilns, (c) Continuous lime kiln for production of approximately 55tons/24hr. (d) Stirred salt cake furnace operating at 1000°F, 11-18 ft dia, 6-10 tons salt/24 hr. (e) Multiple-hearth reactor one with 9 trays, 16 ft dia and 35 ft high roasts 1250 lb/hr iron pyrite. (f) Siements-Martin furnace and heat regenerators a hearth 13 ft wide and 40 ft long makes 10 tons/hr of steel with a residence time of 10 hr.

Klischat, H.J. and Bartha, P., Further development of magnesia spinel bricks with their own specific properties for lining the transition and sintering zones of rotary cement kilns , World Cement, 1992 52-8. 

Kimura, M., Yasuda, Y. and Nishio, H., Development of magnesia spinel bricks for rotary cement kilns in Japan , Interceram Special Issue, 1984 33 Proc. 26th Int Col. Ref., Aachen 1983 344-76. 

Tokunaga, K., Kozuka, H., Honda, T. and Tanemura, F., Further improvement in high temperature strength, coating adherence, and corrosion resistance of magnesia-spinel bricks for rotary cement kiln , UNITECR 91, 1991. 

Table 4-2. Effect of Burning 9 to 10 percent TDF In a Gas and Oil Co-fired Dry Process, Rotary Cement Kiln Controlled by an ESP20 Ash Grove Cement, Durkee, Oregon...

Note that data from a boiler burning TDF at a silicon manufacturing facility, Dow Coming in Midland, Michigan, are reported in Chapter 5 with waste wood boilers, because the primary fuel for this boiler is wood chips. Further, data on TDF use at Boise Cascade, an "other" manufacturing facility, are included in Chapter 4 with cement manufacturing, because the rotary kiln used to manufacture lime is similar to the rotary cement kilns. 

Peray, K. The Rotary Cement Kiln (2nd Ed.), 389 pp., Arnold, London... 

Direct-bonded magnesia-chrome ore materials exhibit a high strength at high temperatures, superior resistance to slags and volume stability up to 1800 C. They also show a much lower tendency to expansion and subsequent spalling as a result of interaction with iron oxides (cf. the follow ing section on chromite materials). Direct--bonded ware finds application in open-hearth furnaces, in electric arc furnaces, in secondary steelmaking processes, in rotary cement kilns, etc. 

Fig. 6.7-37 Typical temperature profiles of gas and solids along the length of a rotary cement kiln [B.69]...

Fig. 6.7-42 Diagram of a dry-process rotary cement kiln employing cyclones for the collection of entrained solids and the drying and pre-heating of the raw materials [6.7.3.2]...

Fig. 6.7-40 Sketch of a chain curtain for the heat transfer from the kiln gases to the slurry in a wet process rotary cement Idln ]B.69] Fig. 6.7-41 Sketches of the relative sizes of different rotary cement Idlns ]B.69]...

Countercurrent rotary cement kiln schematic. (From Baukal, C. E., ed.. Industrial Burners Handbook, Boca Raton, FL CRC Press, 2004.)... 

Another common way of classifying combustors is according to their geometry that includes their shape and orientation. The two most common shapes are rectangular and cylindrical. The two most common orientations are horizontal and vertical, although inclined furnaces are commonly used in certain applications such as rotary cement furnaces. An example of using the shape and orientation of the furnace as a means of classification would be a vertical cylindrical heater (sometimes referred to as a VC) used to heat fluids in the petrochemical industry. Both the furnace shape and orientation have important effects on the heat transfer in the system. They also determine the type of test that will be done. 

The Thring-Newby [5] dimensionless parameter is a similitude parameter, which can be used for nozzle/ enclosure (combustion chamber) scale up purposes. This is a typical situation of the rotary cement kilns where the ratio dp /2L < 0.02. 

The heat and mass balance problem/exercise is addressed by considering the rotary cement kiln a combustion system surrounded by a control volume across... 

Smart, J. R, Jenkins, B. G., and van de Kamp, W. L. "Studies on NOx Emission from an Experiment Rotary Cement Kiln Fire with Mono and Multi-Channel burners." ZKG International, N°8, Gritersloh, 1999. 

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