Vertical Preheater

Introduction of Vertical Preheater

Vertical preheater is one of the main equipment in active lime production.  It mainly used to preheat raw material with poor thermal stability (such as limestone, dolomite and so on). And its main function is to send limestone from the upper part to the body of the preheater.

Making use of high-temperature exhaust gas (800℃--1100℃) discharged from the calcinations kiln to make heat exchange and the preheat the materials evenly into 900℃ in the preheater.

After preheating, there is 30% CaCO3 will decompose and then pushed into the rotary kiln for burning by the hydraulic push rod. So such a calcinations process not only shorten the time of limestone burning in the kiln but also get a high degree of the active lime.

The vertical preheater is used with the rotary kiln, make the high-temperature air from kiln tail fully utilize, play a role in saving energy and reducing consumption, it’s an energy saving and environment - friendly product.

It reduces the loss of line gas resistance and the power of smoke ventilator greatly. It saves the energy consumption. Besides, it has the advantage of easy operation and maintenance, simple masonry and reliable performance.

Features of Vertical Preheater

1. The preheater body is well sealed to keep the cold air outside, which ensures good production process requirements.

2.The preheater has a reasonable internal structure and push head and main parts of the body is made of heat resistant steel, so it can work in 1000~1100℃ high temperature, and have long operation life.

3. The preheater adopts the high-performance hydraulic system to ensure the pusher device to push the material steadily.

4. Recycle the heat energy in waste air that discharge from kiln tail effective, increase utilization ratio of fuel, at the same time, it’s benefits to dedust

5. Effectively recycle heating energy in waste gas from kiln inlet, to ensure the material is preheated equally and reach to preheating temperature

6. With well-combined revenues, the capacity will be increased 30%, thermal efficiency will be increased 40% after use vertical preheater.

Working principle of Vertical Preheater

The working principle of preheater: According to the place of preheater in rotary kiln system, and negative pressure working principle of the preheater. Heat emission is heating convective, the material and air is convection movement.

When the raw materials fed into the preheater, under the negative pressure condition, to prevent cold air into the preheater, the inlet of raw materials must take the effective seal.

Once inside the preheater, the stone comes to rest on a sloped floor, upon which it builds to form a packed bed. Hot process gases from the rotary kiln, below, are pulled through the packed bed of material by an induced draft fan.

The heat content of the gases entering the preheater is such that a nominal 10 to 20 percent of the CO2 in the limestone feed is released in the preheater.

Once through the material bed, the gases exit the preheater through each of two exhaust gas manifolds. Each of the two process gas collection manifolds is connected to one-half of the preheater modules by means of a short exhaust gas duct from each module.

Within preheater, materials after preheating and pre-decomposition, pushing out from preheater to rotary kiln by hydraulic plunger device.

Technical data