Objective
To demonstrate the integration of an advanced conductivity and temperature management system into a dairy processing plant to optimise the potential heat recovery from condensate and hot cooling water and show an overall system efficiency improvement of 6%. The installation to show an original approach to reduce the problem of effluent and capacity by a 2-fold technique of heating and cooling.
Also to complete the design, a new high output ultra violet disinfection system is to be incorporated on the recovered condensate.L%
In the dairy industry and in particular with evaporation plants for the concentration of milk, the condensate and product cooling are not properly managed with regard to other parts of the plant and subsequently primary energy is wasted. Condensate from the first effect of a multi-effect evaporator is normally of a quality standard of 15 us/cm or less and therefore returned directly to the boiler plant. Second and subsequent stages of the evaporator condensate varies from 15 to 50 us/cm reaching as high as 150 us/cm on occasions.
The condensate collection system is to be based on accurate and continuous monitoring and while ever the conductivity is 25 us/cm or less, direct return to the boiler plant will be initiated. The remaining amounts of acceptable condensate in the range 25-40 us/cm (second quality selection) and treated cooling water supplying the finisher and atomising nozzles will be collected and pumped through a new recovery heater battery inserted in the spray drier inlet duct arrangement. The benefit from this technique is 2-fold and unique in its application; not only is the heat recovered but also the unit acts as an air blast cooler and reduces the water discharge and temperature.
While ever there is a flow of condensate the selection process will determine its final destination, and any that is contaminated shall be diverted directly to the site effluent plant.
The highest quality condensate returned to the boiler plant will be stored in a new 65 m3 insulated tank/hot well. This vessel will have a dual purpose in that when ever the drier is required to be washed/C.I.P. the condensate will be used through a new ultra violet (UV) water disinfection system unique to this application.
All other uncontaminated condensate is to be stored in one of two existing 90 m3 tanks and utilised for cleaning and general washing functions together with the process cooling water.
For final cooling there are to be 2-open circuit cooling towers to reduce thedischarge to below 21 deg. C. By centralising the cooling plant, unlike most installations in dairies, the maximum benefit can be obtained in terms of the recovery of heat, reduction in water treatment and fan power by natural cooling and the optimising of efficiencies for the total plant.
The annual energy saving benefits are projected as follows :
535 TOE Thermal
160,000 kWh Electricity
Programme(s)
Topic(s)
Call for proposal
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DEM - Demonstration contractsCoordinator
CO CAVAN
Ireland