Counterflow Pellet Cooler

Counterflow Pellet Cooler Introduction

After crushing, mixing and pelletizing, when pellets come out of the pellet mill, they are always hot and wet, then a pellet cooler is needed. Biomass pellet cooler is a type of counterflow cooling machine with highly automated control system. It can reduce the temperature of pellets from 80~90℃to about 3~5℃ above ambient temperature. And the pellet moisture content is reduced from 17%~18% to 12%~13%. The Counter flow type pellets cooler adopts international advanced counter flow cooling technology, the cooler generates a premium effect of maintaining integrity of the pellets in the working process. With features of large capacity, smoothly functioning, high efficiency, the counter flow pellet cooler has been accepted by plenty of advanced countries. Besides cooling wood pellets, biomass pellet cooler can also be used for cooling feed pellets in feed pellet processing lines. Being one necessity in large capacity biomass pellets and wood pellets production line.

Structure of Counterflow Pellet Cooler

The counter flow cooler consists of these parts:inlet rotary valve, cooling bin, distributor, discharge gate, air outlet, level sensor, hopper, pendulum discharger & overflow sensor.

• Level sensor-adjust the height of pellets in the bin. When the height of the pellets is above certain height, the discharger will work and release the processed pellets. Discharging stops as soon as the product gets below the level sensor.
• Inlet Rotary Valve-equivalent to the feeding device. Hot pellet comes into cooling bin through the inlet rotary valve.
• Rotary Distributor: With the rotary distributor, the pellets can be cooled evenly in the bin room. Using the pendulum discharger, Smoothly gently discharge can be achieved.
• Cooling Room: The cooling process applies the counter flow cooling principle. Cooling air reverse the pellets and the pellet is cooled from the bottom to top gradually, thus the cooling time is increased. this will do good to the production of high quality pellets and to extend the time of pellets storage.
• Pendulum Discharger:The Pendulum Discharger adopts reciprocating discharge, stable operation, small residual.

Counter Flow Cooling Principle

The hot pellets from the pellet mill enter the cooling bin through the inlet rotary valve.Underneath the inlet rotary valve, a distributor ensures even distribution of pellets in the cooler. The pellets is being cooled in the bin by air flow, which enters the bin through the discharge gate and leaves the bin through the air outlet. Pellets layer height is controlled by a level sensor. The level sensor ensures that the product layer is kept at a predetermined height. As soon as pellets activate the level sensor, the pendulum discharger is operated and pellets are discharged through the hopper. Discharging stops as soon as the product gets below the level sensor. In order to prevent overflow, the cooler has been provided with an overflow sensor,which stops product supply to the cooler.

Features of Counterflow Pellets Cooler

• Adopting rotary distributor and oscillating flap discharging institutions. With the help of rotary distributor, biomass pellets can be spread flat in the cooling chamber. The oscillating flap discharging institutions makes the discharge of the processed biomass pellets smooth and efficient.
• The cooling process applies the counter flow cooling principle. Preventing the cold air direct contact with hot pellet in case of pellet fuel surface cracking.Cooling air reverse the pellets and the pellet is cooled from the bottom to top gradually, thus the cooling time is increased. All these will do good to the production of high quality pellets and to extend the time of pellets storage.
• Latest octagon cooling bin design ensures even and sufficient cooling; no cooling dead corner.
• Adopt closed air entry system, enlarge the area of inlet air, ensure efficient cooling effect, avoid cross contamination.
• The cooling effect of this cooling machine is remarkable. With features of large capacity, low energy consumption, low noise and high automation degree, the counter flow pellets cooler is popular in many industrial pellets production plant.

Counter Flow Cooler Technical Parameters

Model	SKLN1.5	SKLN2.5	SKLN4	SKLN6	SKLN8
Cooling volume	1.5m3	2.5m3	4m3	6m3	8m3
Capacity	1-1.5t/h	2-3t/h	3-5t/h	5-7t/h	8-10t/h
Power	0.75kw	0.75kw	1.5kw	1.5kw	1.5kw
Air shutter power	0.37kw	0.55kw	0.55kw	0.55kw	0.55kw

What Should be Noticed When Operate the Counterflow Pellet Cooler?

• 1. The cooler should be based on the strong level ground with the anchor bolts.Before functioning,discharging institutions should be adjusted to horizontal position with a level instrument and the support feet should be fully filled.
• 2. Before feeding, empty the machine first, check whether the internal parts of the machine are normally.
• 3. Start the air-lock device and draught fan before the cooler starting to work.
• 4. Adjust the level indicator position according to the yield requirement. When the yield is high, install the level indicator at top position; on the contrary, install it below.
• 5. Don’t open the observation door when the cooler runs.
• 6. When the cooler stops working, expel the material in the cooler through operating the hand switch.

How to Maintain Counterflow Pellet Cooler?

• Check the fastenings periodically to see if they are loose and falling off or not.
• Clean the cooling zone plates on time, ensure the air current is unobstructed.
• Add lubricating oil to the bearings and electric motor at fixed periods.
• During long-term storage, the pellet cooler should be placed in ventilated, dry, shady and cool place.