Using a Submersible UV Module in a Variable-Level Water Tank
In pharmaceutical production, purified water does not always move directly from one treatment stage to the next. Sometimes it is stored temporarily in intermediate tanks after reverse osmosis. That creates a separate en
In pharmaceutical production, purified water does not always move directly from one treatment stage to the next.
Sometimes it is stored temporarily in intermediate tanks after reverse osmosis. That creates a separate engineering problem: how do you keep the water microbiologically controlled while the tank level constantly changes?
One pharmaceutical facility faced exactly this situation.
The site used horizontal polypropylene tanks with a capacity of up to 2 mΒ³. Water entered from the top and was discharged either by gravity or by pump, so the liquid level was not constant.
The challenge
The goal was to reduce the risk of microbial growth without adding chemical disinfectants.
At the same time, the existing tanks had to remain unchanged.
This ruled out solutions that required major reconstruction, new piping or changes to the production process.
The UV system therefore had to:
operate directly inside the tank;
tolerate changing water levels;
work continuously;
avoid chemical treatment;
require minimal intervention after installation.
Why a submersible UV module was considered
For this kind of application, a conventional flow-through UV reactor is not always the most convenient option.
A flow-through system usually requires dedicated piping and a stable hydraulic path.
In this case, the water was already being stored in a tank, so a submersible UV module could be installed directly inside the reservoir.
A UVL-Mod 19130 module was selected for testing.
The first unit was installed in one of the spare tanks and operated continuously.
Technical configuration
The module used in the project had the following parameters:
lamp power: 130 W;
UV output: 45 W;
module length: 914 mm;
lamp type: amalgam, ozone-free;
rated lamp life: 16,000 hours;
water temperature range: 5β40 Β°C;
maximum water flow: up to 5 mΒ³/h;
recommended installation pipe diameter: 90β100 mm.
The supplied module also included:
PTFE sealing assembly;
protective quartz sleeve;
10 m power cable;
sealed electrical box.
Installation in the tank
The module was installed directly in the reservoir rather than in a separate external UV chamber.
This made it possible to use the existing tank without modifying its basic design.
The main engineering consideration was to position the UV source so that it remained suitable for operation despite changes in water level.
Because the tank was used as part of an existing process, the installation had to be simple and avoid interfering with filling and discharge.
Why changing water level matters
Variable-level tanks are different from closed flow-through reactors.
In a flow reactor, the hydraulic conditions are relatively predictable.
Inside a storage tank, the situation changes over time:
the volume of water changes;
the distance between the UV source and the surrounding water changes;
circulation inside the tank may be uneven;
some areas may receive more UV exposure than others.
For that reason, the position of the submersible module is important.
It has to be installed so that it can operate effectively over the expected working range of the tank.
Initial testing
The customer first tested the system in one spare reservoir.
After several weeks of operation, the installation was considered suitable for the intended task.
The module continued to operate in continuous mode without requiring changes to the tank or the surrounding process.
This test-first approach also reduced the risk of deploying the same configuration across several tanks before confirming that it worked in the real operating environment.
What this case shows
Submersible UV modules can be useful when water must be treated directly inside an existing tank and installing a separate [flow-through reactor] would complicate the system.
The main factors to consider are:
tank geometry;
minimum and maximum water level;
module position;
water circulation inside the tank;
temperature;
maintenance access;
electrical cable routing.
For variable-level reservoirs, the geometry of the installation can be just as important as the lamp power itself.
In this case, the UV module was integrated into an existing 2 mΒ³ polypropylene tank without rebuilding the storage system or changing the production process.
Originally published by Dev.to AI. Aggregated on AIWithGhost for educational purposes β full credit and traffic to the original publisher.