Electrodesalination backwash process
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Dear experts, could you please explain the backwashing process in electrodialysis? Backwashing in electrodialysis is carried out by increasing the flow rate of water injected into the crude oil, and the backwashing valve at the bottom of the tank is opened for flushing; so where does the water used for backwashing end up? Also, is backwashing carried out during the normal electrical desalting process of the feed oil, or is it necessary to shut down the operation? If there is no separate backwash pipeline, how is the backwashing process carried out?
Does no one understand? Push it yourself
First, search the forum or check out the FAQ on atmospheric and vacuum distillation technology.
Electrodesalination backwashing is generally performed online, without the need for shutdown. Before backwashing, the process needs to be adjusted: when performing backwashing of the first-stage electrodesalination unit, open the flushing valve and increase the opening degree of the valve for sending water out from the electrodesalination unit, so that the water from the first stage is discharged through this valve. During the backwash of the secondary electrodesalination unit, since the water removed in this stage is usually to be reinjected into the primary stage, it is necessary to first change the flow path of that water to an external discharge route, and then proceed with flushing the secondary electrodesalination unit. The backwash water eventually goes to the wastewater treatment plant. Generally, reverse flushing pipelines need to be installed for electrodesalination.
You should take a look at the operating procedures for a vacuum distillation unit and you’ll understand
The backwashing process is different from the water injection process. In water injection, water is generally introduced before the mixing valve, whereas backwashing water is directly injected at the bottom of the electrodeionization tank. There are nozzles located at the bottom 【inside】 of the electrodeionization tank; it is the water sprayed by these nozzles that stirs up the deposits at the bottom of the tank, and these deposits are then removed through the drain valve at the bottom of the tank, thereby achieving the purpose of cleaning. The backwashing for electrodialysis is online backwashing, requiring no shutdown.