Paste at the bottom of the dry air flow tower
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As the title suggests, our company uses a gas flow drying tower combined with a cyclone drying bed for drying processes. Since the system was put into operation, there has been a problem of sludge accumulating at the bottom of the drying gas flow tower. It is necessary to open the access cover at the bottom every week or so to clean it; otherwise, a large number of black and yellow spots appear in the finished products during packaging. The sludge that is removed each time is usually in the form of yellow lumps, weighing around 80-100 pounds. Have any experts encountered similar issues? Please help us figure out what could be causing this problem How to improve? Parameters: Fan outlet pressure of 4–6 kPa, bottom temperature of 140–160°C. Is this the reason for insufficient fan airflow? Is the airflow tower poorly designed? Or are there other reasons?
Possible reasons: 1. Insufficient air volume at the feed inlet； 2. Compression occurred during the discharge process by the auger, resulting in lumps
Our drying tower also had this problem before; the reason was that the straight section at the fan’s outlet was too short, with the airflow turning immediately after coming out of the fan and entering the drying tower. After we made changes, this problem no longer occurred
Could you please explain the details and the renovation plan upstairs? Here, there is a straight pipe section of about 4 meters at the outlet of the air flow tower, followed by a 90° elbow; during the screw discharge process, compression occurs, resulting in the formation of lumps. Has this issue occurred with other manufacturers as well? Could you tell me the size requirements for the screw rod?
Try adding a few more blades to the auger’s discharge section to see if it can help break up the lumps.
Increasing the air volume of the fan will solve the problem.
On our conveyor, there are no augers right at the section that leads to the air flow tower; on the other side, there are reverse augers. Does it mean that dense augers need to be added in this empty section on the 5th floor? It’s too troublesome to get the fan running; after analysis, it seems the problem isn’t with the fan itself. The same thing happens when reducing the feed rate. Please share your own experiences~~
The most likely cause of such problems is an improper design of the air flow tower; generally, adjusting the wind pressure first is a good approach. If that doesn’t work, considering adding block dispersing devices in appropriate locations within the auger or the air flow tower is an option. As a last resort, changes to the design of the air flow tower itself will be necessary.
Judging from the pressure at the fan outlet on site (4-6 KPa), it can be said that the fan is functioning properly. The inlet of the air flow tower has a 4-meter straight pipe section, which is theoretically sufficient. The most likely explanation is that the screw conveyor caused compression during the feeding process, resulting in lumps. Solution: 1. Add several protrusions in a circular pattern near the blades at the outlet of the screw conveyor to break up the lumps ； 2. Weld a layer of stainless steel wire mesh inside the vapor flow tower, near the bottom of the screw conveyor ； Feel free to reach out for further communication; my phone number is 15905202732
It’s probably because the fan doesn’t have enough power. The temperature at the bottom of our facility is around 120 degrees, while the temperature in the drying bed is 65 degrees; your bottom temperature seems a bit high
Short-term solution: Install several protrusions in a circular pattern near the blades at the outlet of the screw conveyor to break up the lumps, and weld a layer of stainless steel mesh inside the vapor flow tower, below the screw conveyor； Address the root cause: Increase air volume or raise air pressure (provided that the process and equipment are in good condition)