Production Capacity: 600~10000 t/d
Heat recovery rate: ≥72%
Application: cement, silicate products, new building materials, etc.
The grate cooler is a quenching type cement cooler applied for the cement manufacturing plant. According to the movement mode of the grate, the grate cooler can be divided into three types, rotary type, vibrating type, and push-type grate cooler, with the development of cooler technology, push-type grate cooler is considered the most common clinker cooler in the cement production line.
Parts of grate cooler
The grate cooler is composed of an upper case, lower case, grate plate, grate bed, grate bed transmission, supporting device for grate bed, clinker crusher, funnel, drag chain conveyor, automatic lubricator, cooling air unit, etc.
The grate plate and grate bed structure are the most important parts of the grate cooler, which decide the thickness of the feed layer, yield per unit of grate bed, and working efficiency of the air supply system and heat recovery. So the development of a grate cooler mainly refers to the moderation of the grate plate and grate bed.
Highlights of grate cooler
- The grate cooler adopts a modular construction design and is flexibly adaptable to different scales of the cement kiln.
- There is no need for conveying equipment for material leakage under the grate bed.
- The adjustment and optimization of the grate bed help to cool the clinker uniformly.
- High thermal efficiency.
- High conveying efficiency.
- Low wear and tear, easy to maintain.
Grate cooler function
Cooling clinker
The clinker temperature is an important indicator of the grate cooler performance, which reflects the cooling efficiency of the grate cooler, and also creates conditions for the conveyer, storage, and cement grinding of clinker in subsequent processes. At present, the cooler manufacturer’s guaranteed value for this temperature is 65℃+ ambient temperature. Thirdly, the key is how to accelerate the cooling rate of the clinker.
Heating the secondary air and tertiary air into the kiln and furnace
After the heat exchange between the cold air and the clinker at 1200℃, the clinker cooling heat was recovered. According to different heat transfer efficiency, the temperature of secondary air and tertiary air is between 800~1100℃. Therefore, the heavy material layer above 800mm should be maintained in the high-temperature section of the grate cooler. The corresponding blower under the grate plate must be a high-pressure blower. Moreover, there should be 6-9 rows of inclined fixed grate plate here, in order to improve the heat recovery and material distribution on the grate bed.
Complete the conveying and crushing task of high-temperature clinker
Among the three tasks, increasing the temperature of secondary air and tertiary air is definitely the result of decreasing the clinker temperature, but not any measure to reduce the clinker temperature can increase the secondary air and tertiary air temperature, so the temperature of the clinker discharged from grate cooler should be controlled. When the cooling air of the grate cooler is increased unlimitedly; Or blindly increase the use of air in the high-temperature section; Or increase the use of air in the low-temperature section, although the temperature of the clinker discharged from the grate cooler decreases, it will not increase the temperature of the secondary air and tertiary air into the kiln, but on the contrary, it will increase the temperature of waste gas of grate cooler. At this point, the clinker heat consumption does not decrease, but increases the power consumption of the exhaust fan, and also increases the burden of the dust collector.
Specifications of grate cooler
| Type | Output (t/d) | Grate bed
effective area （t/d）m 2 | Unit area capacity | Drive | Segment |
|---|---|---|---|---|---|
| HCFC-1000 | 1000~1100 | 27.7 | 39.7 | Mechanical | 2 |
| HCFC-1200 | 1200~1300 | 30.5 | 42 6 | Mechanical | 2 |
| HCFC-1500 | 1500~1600 | 36.1 | 44.3 | Mechanical | 2 |
| HCFC-2000 | 2000-2100 | 46.6 | 45 | Mechanical | 2 |
| HCFC-2500 | 2500-2600 | 64.8 | 40.1 | Hydraulic & mechanical | 2 |
| HCFC-3000 | 3000-3200 | 75.a | 42.2 | Hydraulic & mechanical | 2 |
| HCFC-3500 | 3500-3700 | 87.8 | 42.1 | Hydraulic & mechanical | 2 |
| HCFC-4500 | 4000-4500 | 107 5 | 41 9 | Hydraulic | 2 |
| HCFC-5500 | 5000-5500 | 131.8 | 41.7 | Hydraulic | 3 |
| HCFC-6500 | 6000-6500 | 154.6 | 42 | Hydraulic | 3 |
Working principle of grate cooler
How does the grate cooler work? The high-temperature clinker falls into the grate bed from the kiln and is pushed along the full length of the grate bed by the reciprocating grate plate, forming a materials bed of certain thickness. The cooling air blows upward from the bottom of the grate into the grate layer, permeates and diffuses, and cools the hot clinker. After cooling clinker, the cooling air becomes the hot air. The high-temperature hot air is used as combustion air into the kiln and precalciner (pre-decomposer kiln system). Some of the hot air can also be used for drying, the excess hot air is then dusted off and sent back into the atmosphere.
