When a customer needs to increase drying capacity or to replace existing capacity with new equipment, it often means a new drying kiln project. This entails design and all the many variables. At this stage, the old adage well begun is half done is certainly true.
Before starting to prepare a tender for a new drying kiln investment, we need to know what products are to be dried and in what quantities. Is spruce or pine is to be dried? What is the thickness, width and average length of the lumber to be dried? How many cubic metres of sawn timber are dried each year and how this is divided into different products? We need to know the purpose for which the wood is dried and the final wood moisture content and quality required.
Since drying kiln sizes vary from one customer to another, there is no off-the-peg solution. The most import points affecting the size of a drying kiln is kiln load or the size of the sawn goods, which varies depending on the customer. In addition to the drying kiln hall, the kiln equipment is also dimensioned in the preliminary design and design stage to create a kiln of the right capacity for the tender. At the same time, the size of the heating radiators, the capacity of the convection fans and the lengths of the front and back tracks of the drying kiln. Finally, the calculations need to ensure that the type of drying kiln required can fit as required onto the plot planned for it.
3D-models also in preliminary design
3D modelling has long been used in mechanical design and can also be included in the tender preparation stage to illustrate the project.
We supplied the drying kilns for Finland’s largest and most modern sawmill in Rauma. Metsä Fibre’s sawmill used 3D modelling for the first time in all the preliminary design stages: the drying kiln building, the drying unit inside the building, the convector fans and all the process equipment, including the electric motors.
Our mechanical design can make 3D models to the accuracy of a bolt. This also serves work done at the installation stage. Installation errors decrease since the 3D model immediately shows incompatible points, something which is particularly important in large projects. In the industry this is known as collision detection. Fewer mistakes also means more economical and faster installation.
3D modelling can also simulate air masses and how they flow in the drying kiln. 3D flow modelling provides a great tool for optimal implementation.
Towards clinching the deal
Once the structural design work for the drying kiln has been done, the commercial negotiations can begin. The customer wants to be assured that by deciding to go ahead with the investment proposed, the supplier will guarantee that the customer gets the value expected, in other words, drying volumes increase or the quality improves. A new drying kiln almost always means greater capacity.
If the negotiations end in a deal, a new drying kiln project is created. We’ll tell more about this in our next article.
Stay tuned!
Veijo Malmi
Sales Manager
veijo.malmi@heinolasm.fi
+358 50 358 4406
