Problems with feed metering in the reactor
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This post was last edited by robert_lu001 on January 14, 2011, at 09:16. I. It is understood that there are three methods for metering the raw materials fed into the reactor: 1. Metering using metering pumps； 2. Pump + metering tank ； 3. Overall weighing of the reactor, that is, installing a weighing module at the reactor’s support points ； The raw material used in my company is in liquid form; its viscosity is similar to that of water. Which of the three measuring methods mentioned above would be most suitable? Currently, which method is used more frequently? Personally, I prefer the third option. However, some manufacturers believe that the third option is unreliable, as the reactor isn’t in direct contact with the ground; there’s a weighing module in between. This makes the support for the reactor unstable. I’m distressed. Please discuss this among yourselves. Thank you! II. Our company also has a planetary mixer that requires an automatic powder feeding device. The powder in question is nanoscale in size and tends to become very airborne. Could you please recommend any suitable automatic feeding devices? Supplement: The powder we purchased comes in bags; the bag size is 0.5m x 1m.
Reply to 1# robert_lu001: 1. Weighing is the best method; you can choose three-point or four-point support. 2. Vacuum feeding is fine.
The method of overall weighing of the reactor is rather difficult to implement； Before use, the metering pump must be calibrated to determine its linearity ； Before using the pump + metering tank method, the metering tank must also be calibrated. Personally, I recommend the method using a pump + metering tank. For powder feeding, feeders can be used. The poster can search online for manufacturers of such feeders.
Reply to 2# xuejifeng: First of all, thank you! With vacuum feeding, is there a risk of the powder being drawn out through the vacuum port, given that the powder particles are nanoscale in size? Are there any recommended equipment manufacturers for good powder feeders and metering tanks?
Reply to 3# chinazwr: Thanks. Are there any recommended equipment manufacturers of feeders suitable for my process?
In many cases, computational pumps are used to achieve this. Additionally, the material can be drawn into a liquid storage cylinder or tank, and then allowed to flow downward by gravity; the metering is controlled using the scale on the outside of the storage cylinder or tank. Direct measurement is the most accurate, but it’s difficult to implement. Powdered materials can be added using vacuum suction; this is how many paint manufacturers add solid powders during production.
The most advanced metering method is: pump + mass flow meter + control valve. The pump delivers the material, and the cumulative flow rate is set on the flow meter. For example, if the target feed amount is 100 kg, a signal is sent to close the control valve by 50% once 90 kg has been reached; when 100 kg is reached, another signal is sent to completely close the valve.
You on the 8th floor have great foresight; seven years ago, you already knew that this control method was the best. Amazing!