Drying Soybeans in a Portable Dryer

DRYING SOYBEANS IN A PORTABLE DRYER

Portables are rarely used for soybeans and there is not a lot of detailed info around. Due to the high oil content soybeans cannot be dried all heat. They must be dried using the dry & cool mode. In a single fan portable (100 or 1100 Series) that means operating in batch mode. In a multiple fan portable the continuous or batch modes may be used.

DRYING SOYBEANS IN A SINGLE FAN PORTABLE DRYER

1. A single fan portable will have to run in Batch Dry & Cool mode. Running soybeans all   heat no matter how fast you cool them in the bin will cause the oil to go rancid causing condition issues.
2. The manual gives you the step by step to run in batch mode but here are the do’s and don’ts.
3. The plenum temp needs to be no higher than 140 degrees and you may have to change the burner to ON/OFF mode to get that low. The gas pressure will need to be less at the lower temperature for proper burner cycling.
4. You fill the basket in Continuous Flow manually and then change the mode to Batch. The manual gives you the switch settings, but they should all be in Auto except for the Fan Switch which should be in Manual or ON so it will cool the soybeans while they are being unloaded. The Burner which is in Auto will shut off when the dry time is done, but the fan will never stop while the dryer is running.
5. If you can run the unload wide open the Unload Time will be set to 10 minutes which is probably already set to that. You have to increase the time based on how fast you can unload. If you can only run 50% than set the unload for 20 minutes. For other speeds divide the 10 minutes by the percent of unload. For instance if you can run 70% you would take 10 min./.7 to get 14.28 minutes.
6. Set the cool time for 20 minutes. You might get away with 15 minutes if you cool while
unloading and it still gets the soybeans cooled.
7. Start out running on the timer with the grain temp set at 100 degrees and set the Dry time to 12 minutes per point of moisture removed. Monitor each batch for moisture and adjust the time until you get to the desired storage moisture. Once you have dumped several times at the correct moisture start noting the grain temp when it dumps. That temp will be the setting to get the same moisture as you had been getting with time. At this point you can switch to temperature based moisture control and run with automatic moisture control. Set the grain temp to the temp you saw at the last dump and set the Dry Time down to 10 minutes so it is always met early and the grain temperature will control the dump time. Once you get to this point you shouldn’t have to change the grain temperature as the incoming beans change moisture. Only change the grain temperature if the output moisture stays off more than .5% for 2 batches or more. Approximately 5 degrees will change the moisture 1 point as with corn.
Again there is not a lot of info or experience out there so the above is the best way to get going.

MANAGEMENT

1. The plenum must be checked a minimum of once a day, but better if it is done twice a day.
2. The dryer basket must be emptied every day to make sure today’s soybeans, with a lot more debris and pods, are not plugging something up. You shouldn’t leave soybeans in the dryer overnight anyway as soybeans swell and that can cause plugging.
3. Remember beans catch fire a lot easier than corn with their high oil and it isn’t worth trying to skimp on cleaning.

DRYING SOYBEANS IN A MULTIPLE FAN PORTABLE DRYER

1. A multiple fan portable may run in Continuous or Batch Dry & Cool mode. Running soybeans all
heat no matter how fast you cool them in the bin will cause the oil to go rancid causing
condition issues.
2. The manual gives you the step by step to run in batch but here are the do’s and don’ts.
3. The plenum temperatures need to be no higher than 140 degrees and you may have to change the burner(s) to ON/OFF mode to get that low. The gas pressure will need to be less at the lower temperature for proper burner cycling.
4. Most operators will run as always in continuous flow, but batch mode using the batch
instructions above may also be used. In continuous mode on the bottom fan(s), depending on the model, the burner(s) will have to be off to allow cooling to occur in the dryer.
5. Soybeans will dry slower so a lower unload speed will be required. In general the speed settings will be ½ of those for corn. If the corn charts in the manual say to run at 400 or 40% to take out 10 points that will be the speed to start out with for 5 point removal on Soybeans. So whatever the points to be removed on soybeans use twice that number from the corn drying chart to determine initial speed.
6. On a continuous flow the cooling time is set at 1/3 of the pass through time. On soybeans it should be more than adequate for proper cooling.
7. Start out running in manual single speed mode at twice the point removal time from the manual for corn. Allow enough time for the grain to pass completely through the dryer basket and even out. Check the moisture and adjust the speed to achieve the desired storage moisture for the soybeans. At this point note the grain temperature. This will be the set point temperature to maintain the desired moisture. Then you can switch to temperature based moisture control and run with automatic moisture control. You shouldn’t have to change the grain temperature as the incoming beans change moisture. Only change the grain temperature if the output moisture is off more than .5% for an hour or more. Approximately 5 degrees will change the moisture 1 point as with corn. Again there is not a lot of info or experience out there so the above is the best way to get going.

MANAGEMENT

1. The plenum must be checked a minimum of once a day, but better if it is done twice a day.
2. The dryer basket must be emptied every day to make sure today’s beans with a lot more debris and pods isn’t plugging something up. You shouldn’t leave beans in the dryer overnight anyway as beans swell and that can cause plugging.
3. Remember beans catch fire a lot easier than corn with their high oil and it isn’t worth trying to skimp on cleaning.

Gary Woodruff
GSI District Manager IN & KY

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