What is backflow? ?
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Under what circumstances is it necessary to perform a backflow? ? Could someone experienced give me some advice? :handshake
Regulating the backflow essentially involves balancing the outlet pressure and outlet flow; a pipeline is installed from the outlet to the inlet, with a control valve placed in between, known as a bypass valve. This is also a common method of regulation in chemical processing processes. If the outlet flow is higher than the operational requirements, the return valve must be opened to meet the operational objectives; conversely, the inlet valve should be closed or reduced in size.
1 Excessive flow 2 Pumps require a minimum flow rate
Positive displacement pumps cannot have their flow rate adjusted using an outlet valve; instead, a bypass control valve should be used for this purpose. This is where the backflow occurs. The more backflow there is, the less can be transported.
When the minimum operating flow rate of the pump is greater than the minimum flow rate required for the process, backflow is necessary; if it is gas backflow, attention should be paid to cooling.
:handshake :handshake Agree with the original poster’s view
Sometimes it is necessary to stop feeding in the process, but since some pumps do not allow zero flow (positive displacement pumps), there are cases where the process does not permit the pump to have no flow (for example, when transporting a slurry, a lack of flow can cause blockages in the pipes). To ensure flow without feeding material into downstream equipment, a backflow must be created (feeding it back to the feed tank/section)
In simple terms, it’s a cycle – an inlet and outlet cycle. This is widely used in urea evaporation systems and distillation systems; whenever there are issues under normal operating conditions, or when the system parameters are not optimal, or due to other external factors, backflow can be utilized
Post it in the same section; doing so is against the rules, haha. http://bbs.hcbbs.com/viewthread.php?tid=156013&highlight=
Is it the original poster? It seems to be the opinion from the second floor, haha
There is also another aspect: when the compressor or pump has a certain flow rate limit, and the actual flow rate falls below that value, the return valve can be opened to ensure the proper flow rate for the compressor or pump
In tower operations, reflux can also serve to regulate the temperature inside the tower, preventing it from becoming too high: lol
Adjust the temperature balance, or the pressure balance! !
During the liquid filling process, due to the uncertainty in the filling volume which can vary greatly, a higher flow rate occurs when more liquid is being filled. When the filling volume decreases, the pipes are prone to vibration, which may lead to leaks and thus accidents. To reduce vibration, the return section is opened, thereby decreasing the flow rate and eliminating the vibration. If the motor of the filling equipment is replaced with an inverter-driven motor, it is not necessary to use a return valve. :handshake
The function of pump backflow has been basically covered by those upstairs; sometimes, installing a backflow line on the pump also serves to protect it! If it is reflux in the operation of a distillation tower, it is primarily due to process requirements; without reflux, industrial purification and separation would not be possible! I don’t know which type of reflux the original poster is referring to
Excessive pressure at the pump outlet, too low flow rate at the pump outlet
It seems the original poster is referring to the backflow at the pump outlet
One is the requirement of the manufacturing process, and the other is the need to start up the constant-volume equipment.
Both flow rate and pump outlet pressure can be controlled using a return valve