Module 5 is about energy in laundries. Besides introductory knowledge about usage of energy, information about implementing sustainable processes were explained. An important factor is, that saving energy also always means saving water before. Because due to less usage of water, less energy is necessary to heat the water up.
What is the typical application for heat exchangers in tunnel washers?
waste water is heating the ingoing fresh water
rinse water is heating the water for pre-wash
water from the press or spin is heating the water for main wash
Which factors are used to calculate the recovered heat?
time, viscosity, turbulences
temperature difference, mass flow, specific heat capacity
pre-wash temperature, main wash temperature, rinse temperature
Name the first law of thermodynamics
energy is created by heat transfer
energy is destroyed by heat transfer
energy cannot be created or destroyed, it can only change its form
How must a heat exchanger be installed in order to archieve the best efficiency?
with concurrent flow
with countercurrent flow
the efficiencies of concurrent and countercurrent flows are the same
How should a heat exchanger be set up concerning temperature differences?
the fresh water temperature difference should be higher than the waste water temperature difference
the waste water temperature difference should be higher than the fresh water temperature difference
the temperature differences of fresh water and of waste water should be the same
How can the time for heat transfer in a tunnel washer heat exchanger be enlarged?
throttle the rinse flow valve
increase the rinse water amount
increase the rinse water temperature
Which type of heat exchanger is less suitable for soiled medium?
rotating discs heat exchanger
corrugated pipe heat exchanger
plate heat exchanger
What is essential for waste water heat exchangers in laundries?
insensitive to water hammer blows
inspection holes
insulation
Name the advantages of rinsing with high temperature
high extraction temperatures and less wrinkles with mixed fibres
better rinse results and lower moisture retention values
high pre-wash temperatures and better soil removal with blood-stained textiles
Name the advantage of a free-programmable rinse temperature
accurate compliance with hygienic rules
avoidance of pressure-variations in water pipes
avoidance of excessive extraction and pre-wash temperatures