Polysius
The gentle way
to cool the product.
polysius® Fines CoolerThe gentle way to cool the product.
Cool the right material stream — indirectly, efficiently and without compromising product quality. The fines cooler does it indirectly — the coolant never comes into contact with the material, so the product quality is not affected. Six cooler sizes cover throughput rates of up to 180 tph, in cement plants and beyond.
- Maximum throughput rate
- 400 tph
- Delivery programme
- Ten cooler sizes
- Temperature reduction
- can be reduced by up to 40°C
- Heat transfer area
- powdery products from 120°C down to 60-65°C
- Cooling principle
- Indirect — the coolant never touches the material
- Installation
- Compact construction, for both new and existing plants
Application & Principle
In grinding systems it is frequently necessary to reduce the temperature of the material being ground by installing a supplementary cooler. In many cases, indirect and thus gentle cooling processes are preferable to direct cooling, such as water injection into the mill. Indirect cooling does not affect the product quality.
The fines cooler employs the indirect cooling principle: the coolant evacuates the heat without coming into contact with the material being cooled. Depending on the system requirements, either the fine material, the circulating material or the grit rejected by the separator can be cooled. The delivery programme contains ten different cooler sizes for throughput rates of up to 400 tph. The fines cooler is used not only in the cement manufacturing process, but also for cooling fine materials in other industries.
Main advantages of this cooler
Due to the intensive contact between the material and the water-cooled cylinder, good heat transfer is assured in spite of the relatively small dimensions of the cooler
The forced movement of the material prevents deposits from forming
Product quality is not affected, because the coolant never contacts the material
The compact construction assures straightforward installation in both new and existing plants
The drive unit is located at the base of the cooler and is easily accessible for maintenance purposes
Used not only in the cement manufacturing process but also for cooling fine materials in other industries
Which stream is cooled
| Fine material | The finished product leaving the grinding plant, before silo storage |
| Separator grit | The recycled coarse material rejected by the separator |
Design & Principle of Functioning
The fines cooler consists of a vertical cylinder with external water cooling. Inside the cylinder, a rotor with adjustable spiral flights is mounted in antifriction bearings. It is turned from below by a bevel/spur gear unit. The entire drive unit is located at the base of the cooler and is easily accessible for maintenance purposes.
The material to be cooled is fed into the bottom of the cooler and falls onto the rotating distributor plate of the rotor
Centrifugal force distributes the material as a thin layer on the inside of the cylinder
The material is conveyed upwards along the cylinder wall and continuously churned by the rotor flights until it reaches the discharge outlet
The continuously flowing film of water running down the outside of the cylinder efficiently cools the material during this process
The rotor is turned from below by a bevel/spur gear unit; the entire drive unit sits at the base of the cooler
Cooling Water Circuit
The cooling water is distributed by annular water boxes at the top of the cooler, which have conical guide plates to spread the film of water over the surface of the cylinder. At the bottom of the cooler, the heated water is collected in a trough and discharged.The cooling process can operate with either fresh water or recirculating water that has been cooled down to the required temperature in a re-cooling system. If, for instance, slightly salty water has to be used, the components that come into contact with the water can be made of stainless steel.
| Distribution at the top | Annular water boxes with conical guide plates spread the film of water over the cylinder surface |
| The film does the work | The continuously flowing film running down the outside of the cylinder cools the material during the whole upward conveying process |
| Collection at the bottom | The heated water is collected in a trough and discharged |
| Water quality | Fresh water or recirculating water from a re-cooling system; for slightly salty water, water-wetted components can be stainless steel |
Cooler Sizes
The cooling capacity of the system depends on the individual application. Each nominal diameter is available in a tall and a short (A) version and a long (L) version – same diameter, smaller heat transfer area – so the cooler can be matched to the duty and to the available building height.
Depending on availble water qualtiy. The powder cooler can be executed as standard without painting, painted and stainless-steel cooler-shell executions.
Depending on availble water qualtiy. The powder cooler can be executed as standard without painting, painted and stainless-steel cooler-shell executions.
| Sizes: I + II (ØxH) | |||||
| Size: | 1A | 1 | 2A | 2 | 2L |
| Measures: | Ø2,0 x 4,0 m | Ø2,0 x 5,5 m | Ø2,5 x 5,5 m | Ø2,5 x 6,5 m | Ø2,5 x 7,5 m |
| Cross section: | 3,14 m² | 3,14 m² | 4,91 m² | 4,91 m² | 4,91 m² |
| Cooling surface: | 25 m² | 34 m² | 43 m² | 50 m² | 59 m² |
| Throughput capacities: | 0 - 100 t/h | 0 - 180 t/h | |||
| Sizes: III + IV (ØxH) | |||||
| Size: | 3A | 3 | 3L | 4A | 4 |
| Measures: | Ø3,2 x 7,0 m | Ø3,2 x 8,5 m | Ø3,2 x 10 m | Ø4,2 x 10 m | Ø4,2 x 12 m |
| Cross section: | 8,04 m² | 8,04 m² | 8,04 m² | 13,85 m² | 13,85 m² |
| Cooling surface: | 70 m² | 85 m² | 100 m² | 132 m² | 158 m² |
| Throughput capacities: | 0 - 250 t/h | ||||
Selection of the cooler size is based on four figures
Throughput
Material inlet temperature
Cooling water inlet temperature
Required product material outlet temperature, or amount of heat to be dissipated
Maintenance
Inside the cylinder, the rotor with its adjustable spiral flights is mounted in antifriction bearings and turned from below by a bevel/spur gear unit. The entire drive unit is located at the base of the cooler and is easily accessible for maintenance purposes.
Whats this means in operation
Drive unit reachable at floor level — inspection and maintenance without working at height
Spiral flights are adjustable, so the material's dwell time can be matched to the duty
Forced movement of the material prevents deposits from forming inside the cylinder
Where slightly salty water is used, water-wetted components can be made of stainless steel
Compact construction means a straightforward installation in existing plants, too
emergency discharge is at the cooler bottom. and final main gearbox equipped with a auxillary drive for maintenance
Retrofit & Add-on
The compact construction of the fines cooler assures straightforward installation in both new and existing plants — which is why it is most often specified as a supplementary machine rather than part of the original scope.
| Fit the short A version where headroom is tight | Size I A is 6,190 mm high against 7,620 mm for size I at the same ø 2.0 m diameter — at a reduced heat transfer area of 25 m² instead of 34 m² |
| Stainless steel for difficult water | Where the available cooling water is slightly salty or with high chlorine content or high iron the components in contact with the water can be made of stainless steel or as painted execution. |
| Close the water circuit | The cooler runs on fresh water or on recirculating water cooled in a re-cooling system |
| Adjust the spiral flights | The rotor's spiral flights are adjustable, matching conveying behaviour and dwell time to the actual duty |
| Cool a stream other than the product | The cooler can be placed on the fine material, the circulating material or the separator grit |
Add-ons
1. Rubber water curtain for cooler which installed in buildings
Water curtain are installed around powder coolers as a guard to prevent that water is spreading around for hygiene (reduction of legionella risk) and pollution reasons
A curtain minimizes the splashing water, which sometimes makes cost-intensive water refilling necessary
Furthermore, is a cooler with a curtain less sensitive to wind, which will improve the cooling efficiency
2. Steel curtain for outside of building installations
Powder coolers has to be housed while operation
Steel curtain often will be installed around cement coolers as a guard to prevent that water is spreading around and pollution reasons
A curtain minimizes the splashing water, which sometimes makes cost-intensive water refilling necessary
Furthermore, is a cooler with a curtain less sensitive to wind, which will improve the cooling efficiency
3. Water recooling, treatment system
We can also supply a preassembled container water re-cooling system with integrated water treatment system, which is supplied with moderate amounts of water.
Water and water of the appropriate quality is problematic in various areas in the world and also very expensive. In order to conserve/minimize resources and operating costs, we can offer a closed water re-cooling system.
The re-cooling system installed in a container is positioned directly next to the cement cooler.
The forced movement of the material prevents deposits from forming — and the intensive contact with the water-cooled cylinder assures good heat transfer in spite of the relatively small dimensions of the cooler.