Reducing water use in traditional dyeing machines
The new generation of dyeing machines are more water efficient than older ones.
The intrinsic water
efficiency of a machine is measured by the liquor
ratio. This is the ratio of water to thread once
the machine is filled, and typical older machines
will operate at a ratio of 8:1 while more modern
machines, can operate at 4.5:1. This is a 44%
saving in water for the same output, and is largely
achieved by improved design of pumps and
pipework. However, while all our new machines
are low liquor ratio designs, with almost 2000
dyeing machines in use, we have a lot of older
machines that still have years of life in them.
Our team in Bangladesh have been challenging
themselves to find ways to achieve lower liquor
ratios on old machines without modifying the
machines themselves. Through a combination of
maximising the thread load, optimising the water
level, rationalising flow direction and adjusting the
pump speeds they have managed to reduce the
liquor ratio from 8:1 to 6.5:1, a 19% reduction
in water used. The water saving also impacts on
energy use as a lower water volume takes less heat
energy to raise it to operating temperatures.
We will be spreading this innovative approach
across other dyehouses in 2020.
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