Controlled CO₂ Diffusion for pH Stabilisation Prior to Chlorine Residual Analysis
Designed to stabilise sample pH before digital or automatic chlorine residual measurement in water treatment applications.
The Boltac Carbon Dioxide Diffuser is designed and manufactured to provide a small, controlled adjustable CO₂ dose into a water sample line prior to chlorine residual analysis. Its purpose is to stabilise sample pH so that chlorine measurement can be conducted under more stable and consistent pH conditions. The diffuser has been successfully used where earlier electronic controls failed to meet plant requirements for stringent chlorine residual control and recording. Today, it could be considered as a means of control where budget restrictions prevent the purchase or upgrade to new electronic means of pH stabilization.
CO₂ gas is metered through a needle valve-controlled rotameter tube, allowing the flow rate to be observed, adjusted and recorded before the gas is introduced into the sample within the diffuser element. The treated sample then flows to the chlorine residual analyser. The use of the diffuser can contribute to better chlorination control, an additional layer of quality assurance, and improved chlorine efficiency.
The problem and the Boltac solution
| Operational Problem | The Boltac Engineering Solution |
|---|---|
| Gas Stripping & Waste | Micro-Bubble Technology Some diffusers create large bubbles that surface too quickly. Boltac diffusers are engineered for maximum gas-to-liquid interface, ensuring CO2 is fully absorbed into the water column before reaching the surface. |
| Mineral Scaling & Clogging | Self-Cleaning Orifice Design Localized pH drops often cause "calcification" at the injection point. Our diffusers utilize specific materials that resist mineral attachment, extending service intervals and reducing maintenance downtime. |
| Inconsistent pH Control | Precision Flow Distribution Uneven gas distribution leads to "slugs" of acidic water. Boltac Diffusers provide a steady, uniform curtain of gas, allowing plant SCADA systems to more easily maintain stable and accurate Cl2 dosing. |
Key Benefits
- Designed for pH control of chlorine samples prior to residual analysis.
- Metered CO₂ flow via rotameter tube for visible and recordable gas flow rates.
- Supports more consistent chlorine residual measurement conditions.
- Can improve chlorination control and quality assurance.
- Usually operates with long cylinder life depending on site requirements.
Best For:
Water treatment applications where the chlorine sample pH must be stabilised before digital or automatic chlorine residual analysis.
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FAQ
Q: What is the gas-to-liquid transfer efficiency of a Boltac diffuser?
A: Boltac diffusers are engineered for maximum CO2 absorption rates. By generating a uniform curtain of micro-bubbles, our technology increases the interfacial surface area. This ensures that CO2 gas is fully dissolved into the water column before it reaches the analyser, significantly reducing gas waste compared to some other bubblers.
Q: How does the Boltac CO2 diffuser resist mineral calcification?
A: Instead of relying on specific metals, Boltac utilises corrosion-resistant surface materials known for their resistance to build-up. These engineering choices prevent localized pH drops from allowing mineral scale to “anchor” to the diffuser, maintaining consistent flow and extending maintenance intervals.
Q: Can these diffusers be integrated with existing SCADA systems?
A: No. The linear response of our micro-bubble distribution allows for easily controlled pH adjustments in the sample going to the Chlorine analyser. This stability enables SCADA-controlled dosing systems to maintain tighter set-points with less “hunting” or oscillation in the downstream pH values.