Case study: Baghouses can be a big source of compressed air leaks
Flowmeter VA 570 used for baghouse monitoring
| Location | South Africa |
| Year of Implementation | 2019, metres have been running since then. |
| Key Characteristics | Flowmeters installed at each baghouse to monitor compressed air consumption of each baghouse. The detected leaks added up to about 45% of the whole system. By having permanent flow meters installed it is now possible to maintain the system and keep the leakage rate at a minimum. |
| Achieved Efficiency Gains | It was possible to take a 560kW compressor offline which lead to an annual energy saving of 4816 MWh. |
The client for this project originally commissioned CS Instruments to do a compressed air system optimisation audit (CASO) on their compressed air system. The compressors of the client run 24/7 all year around and the combined compressor capacity is in excess of 1 MW.
The audit revealed an overall system leakage rate of 43-45 % and the majority of the leaks were allocated to faulty pulsating valves in the companies bag houses. By monitoring the compressed air flow into each of the 12 bag houses it was possible to pick up the faults and repair the leaking valves.
By having permanent flow meters installed it is possible to maintain the system and keep the leakage rate at a minimum. The whole project enabled the company to take a 560kW turbine compressor offline and put it on standby for redundancy. In other words, the total leakage rate combined for all 12 bag houses exceeded the capacity of a 560kW compressor.
As a solution, twelve CS Instruments inline flow meters and two data loggers were permanently installed to monitor the system on a continuous base.
Innovation and Achieved Energy Efficiency
Compressed air systems in South Africa have in general high leakage rates because most companies do not monitor important parameters on their compressed air system. Hence, using measuring equipment to begin with was already an innovative step.
The measuring technology that was installed are flowmeters. In this case the flowmeters help to see the air consumption of each baghouse. Through online monitoring of the air consumption of each bag house it is possible to see if the bag house has leaks or not. The innovative part in this case was that the majority of the leaks could be identified and that the measuring technology gave the client a tool to calculate their energy consumption. Going forward, the client can monitor the flow and hence allocate costs better. A preventative maintenance tool is now at hand and can be used continuously.
The compressed air systems capacity of the client was significant and the total leakage was about 45%. By monitoring the compressed air system with the flowmeters0, it was possible to take a 560kW compressor offline. This lead to an annual energy saving of 4816 MWh.
Market Relevance and Replicability
Compressed air systems always have occurring leaks, and they usually get bigger and higher in number over time. The mere change in ambient conditions can be the cause of leaks occurring. The change in ambient temperature can make the material of the the pipework expands and contracts a little each time. Hence over time, leakages can occur at basically any joint, fitting or flange. A pressurised system will only speed up this process. Normally this issue is dealt with by doing regular leak audits (three to four times a year would be advisable) in order to keep the leakage rate at a minimum. In South Africa, monitoring air flows is not common practice, this can lead to large, undetected leakage rates, often exceeding 50% of total compressed air capacity.
In compressed air systems of about 180 kilowatts and upwards (of installed compressor capacity), it makes financial sense to monitor the system on an ongoing basis. The monitoring helps to reduce leakages to a minimum and to run as energy efficiently as possible. The replicability for these monitoring systems is hence very high.
CS Instruments offers sensors for all relevant parameters to monitor compressed air and gas systems, hence is able to provide a full portfolio of solutions. The product portfolio includes flowmeters, dewpoint sensors, pressure sensors, leak detection equipment, displays, dataloggers, monitoring software, air quality measurement solutions and onsite services.
About CS Instruments
CS Instruments is a German company which specialises in compressed air and gas monitoring equipment. All sensors are developed and manufactured in Germany. Locally, CS instruments also offers like compressed air system optimisation audits (CASO), air quality audits and leak detection audits. The technology used to identify the energy saving opportunity is 100% German and the same technology is also used to maintain the achieved energy savings.
For more info please contact us:
CS Instruments (Pty) ltd.
Cape Town Head Office:
021 557 5618
Johannesburg branch:
010 013 0306
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