Overview and Understanding of the Qingdao SUNRUI BalClor? Ballast Water Management System (BWMS)

I have only encountered two types of ballast water treatment systems: JEF and Qingdao SUNRUI. The JEF system uses filtration and chemical processes, but back then I was inexperienced, and since this system was rarely used, I don’t know much about it. Therefore, I won’t provide any introduction to it here.

Below, I will describe my understanding of the Qingdao SUNRUI ballast water management system (BWMS).

1. Basic Principle

(1) The treatment process of BalClor? BWMS for ballast water can be divided into:

• Filtration: The automatic backwash filter with 50 μm filtering capacity is used to filter the ballast water. This process filters out most marine organisms and solid particles larger than 50 μm.
• Electrolysis: A small flow of seawater is diverted from the main ballast water pipeline and passes through the electrolysis unit. Electrolysis produces a high concentration of sodium hypochlorite solution. After separating the hydrogen gas, the solution is returned to the main ballast water pipeline, where it is mixed and diluted with the ballast water to a specific concentration, achieving the required sterilization effect by reducing the remaining plankton, pathogens, larvae, or spores after filtration.

Note: When seawater enters the electrolytic cell, the electrolysis reaction mechanism is as follows:

Anode:

Cathode:

Chlorine gas produced at the anode quickly dissolves in the seawater, generating hypochlorous acid and hydrochloric acid:

Therefore, the overall reaction is:

In fact, this reaction principle is similar to the Marine Growth Prevention System (MGPS).

• TRO: The flow rate of neutralizer injected into the pipeline is automatically controlled by the system based on the concentration feedback from the TRO (Total Residual Oxidant) analyzer.

(2) The treatment process of BalClor? BWMS for de-ballasting can be divided into:

• Neutralization: During de-ballasting, the neutralization system is activated, and a neutralizing agent is injected into the discharge pipeline to neutralize the chlorine ions in the pipeline.

• TRO: The flow rate of neutralizer injected into the pipeline is automatically controlled by the system based on the concentration feedback from the TRO analyzer.

How the Ballast Water Treatment System Works

2. Important Parts of the System

(1) Automatic Backwash Filter Unit (AFU)

The automatic backwash filter is made of strong duplex stainless steel to make sure it filters seawater well and lasts a long time. It has several filters inside, which clean seawater effectively and reduce the need for maintenance.

Inside the filter, there is a special structure that traps sea creatures and dirt.

(2) Sewage Pump (EQ02)

While taking in ballast water, the sewage pump automatically starts based on the backwash needs of the AFU and pumps out dirty seawater to the outside.

3. Electrolysis Unit (EDU)

The electrolysis unit is the most important part of the system, and its key component is the electrolytic cell. This cell has a tubular shape, allowing it to work efficiently for the entire life of the ship, with almost no need for repairs or replacement.

How the Electrolysis Unit Works:

The electrolysis unit might seem complex, but it helps to understand its parts step by step. Seawater from the main ballast pipeline is pumped through several components:

① Inlet solenoid valve ② Pressure regulating valve ③ Byte Flow Control valve ④ Salinity meter ⑤ Pressure sensor ⑥ Flow meter ⑦ Electrolytic cell ⑧ Temperature sensor ⑨ Cyclone separator ⑩ Buffer tank

Finally, the seawater is returned to the ballast water main pipeline through a dosing unit. The pressure regulating valve and Byte Flow Control valve are adjusted at the factory and should not be changed unless absolutely necessary.

What Happens in the Electrolytic Cell:

Inside the cell, the seawater undergoes a chemical reaction, producing two things: sodium hypochlorite (a disinfectant) and hydrogen gas. While the sodium hypochlorite is used to clean the ballast water, we don’t need the hydrogen gas. Hydrogen is a flammable gas, and since ship cabins are hot, releasing too much hydrogen into them can be dangerous. That’s why we need to safely remove the hydrogen and release it outside.

The cyclone separator is installed to handle this. It separates the gas from the liquid. The gas spins around inside the device, and the heavier liquid is pushed to the outer walls. The sodium hypochlorite liquid is collected at the bottom and pumped back into the ballast water system to disinfect it. The hydrogen gas is sent out through a different exit.

The electrolysis unit also has two fans to dilute the hydrogen gas and keep its concentration below 1%. One fan is always in use, while the other is a backup.

The dosing unit contains a dosing pump and a solenoid valve. The dosing pump injects the sodium hypochlorite into the main ballast pipeline, and the flow is adjusted automatically based on feedback from the TRO (Total Residual Oxidant) sensor.