Heat exchanger for waste recovery of cattle slurry
SACOME have recently supplied an equipment intended for the heating of cattle slurry, as part of a pioneering project for biowaste recovery in Spain. This heat exchanger, built into a biogas production line within a major livestock holding, enables our customer to enhance the efficiency in the production of biogas in the 4 anaerobic digesters making up the plant site. The installation is able to heat up over 1.000 tons per day of cattle slurry, using as service media process water coming from other part of the plant. The thermal duty of the installation is over 1 Megawatt.
In order to define the thermal properties of the product, having a dry matter of 11%, we have worked in close cooperation with our client and with laboratories from different universities, thus optimizing the thermal design of the heat exchanger, but leaving a certain overdesign factor for such a varying product.
With regard to the adopted solution, we proposed our I-TF20-I model, monotube heat exchanger of our Industrial Line, the best choice to get an optimal heat transfer as well as to minimize the risk of plugging for a product of this kind.
Selection of the material for the process side components in the waste recovery of cattle slurry
Several alternatives were proposed to the client by the engineers from our Technical Department. Finally we have offered them 2 parallel lines with manifolds to split the hot water stream, which has made a more efficient use of the available service water flowrate.
Particular attention has been given by our technicians to the selection of the material for the process side components, with the aim to avoid corrosion issues due to the possible presence of certain precipitates in the product, in particular struvite.
At last, we have proposed the client a configuration that allows the disassembly of all the interconnection and manifolds in order to access to the tubes and proceed to maintenance and mechanical cleaning tasks.
The importance of rheology in the design of any processing plant is crucial since the sizing of many of the elements composing it is very dependent on this “resistance”, also taking special relevance with food products: heat exchangers, pipes, valves, pumps, mixers, etc.
To design a heat exchanger it is necessary to have certain data, such as the process flow rate, the temperature and the physical properties of products.
Hairpin heat exchangers have a more efficient and economical design compared to a multiple pass heat exchanger when the process requires a temperature crossing between the cold and hot fluid.