Water management through water monitoring

 

Technical description

 

Water is the most important resource of textile finishing industries. All wet processes are based on water. Water consumption is directly or indirectly related with energy and chemicals consumption and wastewater hydraulic load. Excess water consumption increases thermal and electrical energy and chemical consumption in the processes. Water management is very important in the textile finishing industry to reduce resource consumption and sustain textile processes. Water management will only be possible if water consumption in the processes is measured, monitored and controlled. Mostly water consumption in the textile finishing industry is not measured, monitored and managed due to its availability in abundance, particularly where fresh water costs are low. Often, the management and workers do not realize the importance of water and associated resource wastage due to its inappropriate use in the process.

Water monitoring is very important for water management by installing water flow meters at main water turbines, different wet process sections, process machines and utilities (see Figure 1). After water monitoring, its analysis and benchmarking is important to assess the status of water consumption in the industry and to know whether its consumption is optimum or consuming huge amount of water as compared with other similar industries. Establishing water consumption benchmarking i.e. liter of water consumed per kilogram of finished fabric, and its improvement by taking water conservation measures will improve water management in the industry.  

Figure 1: Water flow meter installed at boiler feed water supply line

Achieved environmental benefits:

  • Water conservation
  • Reduction in hydraulic load of wastewater treatment plant

Operational data: 

Water monitoring facilitates production floor professionals to control water consumption at machines. There is one example of the industry that reduced about 25% of its water consumption for continuous pretreatment machine just by monitoring daily water consumption and then optimizing without any other intervention in the machine.

Table 1 below shows a real example for compiling machine-specific water consumption monitoring data of continuous wet processing machines. As it is a real example of a textile finishing industry in Pakistan, some figures are missing but it can be easily seen that the washing processes for continuous pre-treatment (continuous pre-treatment lines and mercerization plants) is low, i.e. water-efficient whereas the specific consumption for the continuous washing machine for after-washing of dyed fabric is high. As a benchmark, the figures from the technique on counter-current washing can be taken (see the technique concerning counter-current washing). The monitoring of steam and electricity is carried out similarly. The daily determination of the specific water (and energy) consumption allows the identification of deviation of standard operating conditions and thus, immediate action can be taken.

Table 1: Real example for monitoring the water consumption for different continuous wet processing of cotton and cotton/polyester woven fabric

Table 2 below shows another example from another textile finishing industry where, in addition to water, the absolute and specific consumption is given for steam and electricity (power). Here, the specific consumption is referred to one meter and not to one kilogram of fabric.

Table 2: Monitoring data for water, steam and electricity consumption of two continuous woven fabric wet processing machines

Cross media effects:

No relevant cross media effect is known.

Technical considerations relevant to applicability: 

This measure is applicable to all the textile finishing industries. The water flow meters should be selected carefully. Most of the times, the water flow meters malfunction is due to water quality issues. The electromagnetic type water flow meters are preferred due to their durability whereas the impeller type flow meters malfunction due to clogging and scaling. The electromagnetic type flow meters are expensive than impeller type. The price of the flow meter depends upon its type and size.

Economics:

The direct calculation of the benefits from the implementation of water flow meters is not possible. However, the monitoring is usually associated with significant savings of water and energy, especially directly after the implementation of water meters.

Driving force for implementation: 

  • Financial benefits
  • Resource conservation
  • Sustainability of textile business

Reference industry:

  • Kohinoor Mills Limited, Raiwind Manga Road, Lahore
  • The Crescent Textile Mills Limited, Sargodha Road, Faisalabad
  • Nishat Chunian, Raiwind, Lahore
  • Abdur Rehman Corporation, Khurrianwala Road, Faisalabad
  • Sarena Textile Industry Pvt. Ltd, Sheikhupura Road, Lahore
  • Klash Private Limited, Faisalabad


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