Self Contained Disinfection Chemical Dosing Systems
Sheers specialise in the design, installation and commissioning of PRIMARY & SECONDARY DISINFECTION modular build chemical dosing systems. These range from small single tank and pump dosing units to multiple 15,000 litre tank systems. Increasingly our clients specify a requirement for off-site build (DfMA) and testing (FAT) of modular or fully packaged systems.
Gases in Liquid Chemical Systems
The presence of gasses within a liquid chemical can result in:
- Inaccurate measurement of chemical dose rates
- Air-locking of dosing pumps
- Water quality failures
- Increased callouts of maintenance personnel
When designing a chemical dosing system, it is imperative that the physical properties of the chemical are fully understood.
Some chemicals are prone to ‘gassing off’ e.g. Sodium Hypochlorite. This gassing off manifests itself as small bubbles forming in the dosing lines of a system. If the gas accumulates in the system, the dosing pumps can become airlocked resulting in the loss of dosing.
When assessing the risk of this occurring, chemical concentration is an important factor. For example: 5% w/w hypochlorite is far less prone to gassing off than a 14% w/w solution. One option is to reduce the hypochlorite concentration, measured and controlled dilution with water and Sheers possess a number of verified designs to provide this.
Gassing off is usually detected by loss of flow of treatment chemical. Sheers systems are designed to mitigate the effects of this and, therefore, to maintain dosing.
Our dosing kiosks are fully bunded, typically with separate rooms for chemical tank storage, dosing equipment and process control. Increased security rated kiosks are available to suit requirements (LPCB SR3 and SR4 are an increasingly frequent request).
The systems are fully fitted out at our works in Darlington to the highest standards and are fully Factory Accepted Tested before leaving for our customers sites ensuring that the customer can carry out key quality checks against their specific standards and specifications. Systems are fully function tested (FAT – Factory Acceptance Test) ensuring that the system delivers the required dosing rate for the application.
Typical features are;
- Integrated Fill Cabinet with interlocking fill valves, fill lines and fill panel. The panel is fully equipped with a high-level warning beacon, mute button and tank level display.
- Bulk Storage Tanks with automatic shut off valves.
- Dosing skids with enclosed pumps, pipework, valves and instrumentation. These also incorporate leak detection devices to warn of chemical leaks for unmanned applications which can raise alarms or shut the system down to reduce risks of accidents or environmental damage.
- Auto purge to eliminate gas build up within the system.
- Control panels with plc control and HMI interfacing panel.
- Heating and Lighting is installed to ensure the system can be maintained safely and ensure frost protection of the system.
Other optional items may include;
- Point of Application Cabinets
- Dual Contained Dosing Lines
- Safety Shower and Eye Wash Units
- Hazardous area units can also be offered and be tailored to meet customers needs.