What is vertical shaft kiln?
The vertical shaft kiln, or vertical kiln, is a type of clinker calcination equipment used in small and medium-sized cement plants. It can complete the comprehensive mechanized operation of feeding, calcining, crushing and discharging.
What is a shaft kiln?
As opposed to rotary kilns, shaft kilns are static production systems in which the raw material (limestone in various particle sizes) is fed into the kiln from the top, from where it moves downwards through the kiln shaft purely by gravity.
What are the two types of kiln used to produce lime?
Types of kiln Permanent lime kilns fall into two broad categories: “flare kilns” also known as “intermittent” or “periodic” kilns; and “draw kilns” also known as “perpetual” or “running” kilns. In a flare kiln, a bottom layer of coal was built up and the kiln above filled solely with chalk.
How does a cement rotary kiln work?
The rotary kiln Rawmix is fed in at the upper end, and the rotation of the kiln causes it gradually to move downhill to the other end of the kiln. In the cooler the air is heated by the cooling clinker, so that it may be 400 to 800 °C before it enters the kiln, thus causing intense and rapid combustion of the fuel.
How does a vertical kiln work?
In the vertical kiln, the material moves from top to bottom, and the combustion air moves from bottom to top. The heat carried by the high-temperature materials preheats the combustion air. The heat consumption of clinker in modern shaft kiln can be controlled within (600 ~ 700) × 4.18kj.
What is a rotary kiln used for?
A rotary kiln is a pyroprocessing device used to raise materials to a high temperature (calcination) in a continuous process. Materials produced using rotary kilns include: Cement.
What temperature is a lime kiln?
A lime kiln is used to produce quicklime through the calcination of limestone (calcium carbonate). This reaction takes place at 900 °C but a temperature around 1000 °C is usually used to make the reaction precede quickly. 2 Quicklime was used to make plaster and mortar for building construction.
What fuel is used in cement kilns?
Coal
Coal is the primary fuel burned in cement kilns, but petroleum coke, natural gas, and oil are also consumed.
What is the temperature range in cement kiln?
The tempeture range in a cement kiln is. 500 to 1000ºC. 1000 to 1200ºC. 1300 to 1500ºC.
How does a lime kiln work?
A lime kiln is used to produce quicklime through the calcination of limestone (calcium carbonate). Hydrated lime can then be produced by adding water to the quicklime. At this point, carbon dioxide in the atmosphere or from industrial processes reacts with hydrated lime to convert it back to limestone.
How many zones does a rotary kiln have?
dry process, the raw ingredients are prepared and stored without addition of water, and the kiln is commonly divided into five zones (Table 2 and Fig. 3). The refractory brick arrangement and anzast layer in rotary kiln are presented in Fig. 4.
What kind of kiln is vertical shaft kiln?
Shaft kiln, also called vertical shaft kiln or vertical kiln, is a kind of vertical set stationary cement kiln, usually applied in the cement production line, lime production line, etc.
When was the first continuous cement kiln made?
Around 1885, experiments began on design of continuous kilns. One design was the shaft kiln, similar in design to a blast furnace. Rawmix in the form of lumps and fuel were continuously added at the top, and clinker was continually withdrawn at the bottom.
Where is the cooling zone in a shaft kiln?
Cooling Zone. The cooling zone is located between the calcining zone and the kiln bottom. In this area, the clinker exchanges heat with the cold air blown from kiln bottom so as to cool down the clinker temperature, meanwhile, the cold air is heated and then enters the calcining zone as an oxidizingair.
What was the original shape of the lime kiln?
The basic, egg-cup shaped lime kiln was provided with a conical or beehive shaped extension to increase draught and thus obtain the higher temperature needed to make cement clinker. For nearly half a century, this design, and minor modifications, remained the only method of manufacture.