Kiln patent

The Calcimatic is a patented kiln of Canadian origin that is radically different from other kiln types. It consists of a circular traveling hearth of variable speed, supported on two concentric tiers of rollers. Kiln feed of 12.7 mm is fed onto the hearth in a 2.5—10 cm bed from a preheater chamber. The kiln is usually fired with natural gas or fuel oil, although the option of using pulverized coal has also been developed. After great interest, resulting in sales of many units throughout the world, the popularity of the Calcimatic has ebbed because of disappointment in the unit s mediocre thermal efficiency. 

Fig. 5. Schematic of the Kennedy van Saun (KVS) patented low pressure drop (LPD) preheater/rotary kiln lime calcining system available in sites...

FIG. 12-66 Kiln chain installation (patented). (Allis-Chalmers Coip.)... 

It is expected that the use of whole scrap tires will increase in both new and conventional cement kilns, based on two recent patents. 

They emphasized the cumulative impacts of pollutants on communities - the combined effects of all sources of contamination, not just one particular pollutant or facility. For many years, risk decisions had been made in an artificial vacuum, considering one oil refinery, or one cement kiln, or one hazardous waste incinerator, ignoring all other sources of contamination in the general vicinity. This narrow perspective had burdened certain communities with numerous sources of contamination, each of which individually was deemed acceptable yet in the aggregate created a patently unhealthful environment. 

OEC has been used to reduce NOx in a fixed-based resource recovery process.20 Giant Resource Recovery (GRR) is a subsidiary of the Giant Group, Ltd., which is involved with cement manufacture and the use of waste materials as fuel and raw materials supplements. GRR processes creosote-contaminated soil through countercurrent rotary kilns. By a patented process, the decontaminated soil is then used as a raw material for cement production, thus replacing a certain portion of the traditional feed material stream. The combustion products are ducted into the cement kilns. 

The development of the rotary kiln, now predominantly used for the production of Portland cement, started around the late 1870s but the technology was not patented until 1885 (Ransome [B.69]). A rotary kiln (Fig. 6.7-35) is a long refractory-lined steel cylinder that is inclined at about 3-6° to the horizontal. At the lower end is a burner (coal, oil, or gas fired) and the material to be calcined enters on the other end. While passing down the kiln, chemical and physical reactions take place in the oxidizing atmosphere. Hot clinker emerges at the burner end and must be suitably cooled before being milled to yield cement. The rotary kiln process may be carried out with wet (slurry), semi-dry, or dry feed. 

FIGURE 43.15 Fluidized bed dryers (a) with heating tubes (b) with superheated steam heating, 1—screw conveyor 2—stationary hlade 3—cylinder 4—side cyclone 5—ejector 6—stationary vanes 7—superheater, 8— impeller, 9—top outlet 10—screw conveyor (Courtesy of Niro A/S) (c) rotary kiln dryer using sands heated in a fluidized hed humer. (Adapted from Isheim, M.C., US Patent 4,248,164, 1981.)... 

Various modifications to the commercial process have been suggested in the patent literature. These are primarily focused on the production of STTP with particular properties such as low bulk densities [7], increased abrasion resistance [8], and improved solubility properties [9,10]. Crystalline or coarse tripolyphosphate particles can also be obtained by spraying seed crystals with the desired characteristics during the production process [11]. The use of rotary kilns to obtain a granular product in both stages of the two-stage process has been discussed previously [12]. In this case, the intermediate product is ground and water is added before calcination. 

Bar Kiln, Bar Dryer, A pre-fabricated, steel-cased tunnel kiln for the rapid firing of heavy clay products is combined in a two-storey arrangement with a rapid dryer in which the ware is set on the same kiln cars as are used for firing. (Occidental Industries, Paris). Barratt-Halsall Firenioiith. A design for a stoker-fired firemouth for a pottery BOTTLE OVEN (q.v.) a subsidiary flue system links all the firemouths around the oven wall to assist in temperature equalization. The design was patented by... 

Belgian Kiln. A type of annular kiln patented by a Belgian, D. Enghiens (Brit.Pats.18281,1891 22008,1894 ... 

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