USER REPORT Extraction
USER REPORT Extraction and briquetting plant from one source The DFH Deutsche Fertighaus Holding AG is the largest company for prefabricated houses in Germany. More than 3,000 detached and semi-detached houses are built nationwide every year. DFH was founded in 2001 with the sales divisions massa haus, allkauf haus and OKAL Haus. Since its foundation, the company has developed successfully and can look back on extraordinary growth figures in comparison with others in this branch of industry. Recently DFH massively expanded its production capacities and invested in a new joinery hall with state-of-the-art CNC-controlled joinery systems and an innovative wooden wall production line at the company headquarter in Simmern. The timber-frame hall processes around 110,000 m 3 of timber per year. The new wall production line represents an innovation in the prefabricated house sector, as contour profiles for gables, external walls and flap tiles are produced at the same time. As part of the growth strategy, the production capacities were expanded in 2018 again. Also a new extraction system was required for the enlarged machine park. The task submitted to SPÄNEX had the following special features: • The chips should be briquetted and used to heat the production hall. • The excess amount of chips should also be used thermally at another location. Further requirements for the new extraction system: • machines to be connected: 7 • maximal extraction air quantity (incl. reserve): 30,000 m 3 /h • operation mode: continuously • air return: 100 % • shredding of lumpy wood residues, • quiet operation • optimum energy efficiency. In particular, the arrangement of the filter system due to the cramped space conditions and the noise level to be maintained at the property boundary, due to the direct neighbourhood of a home improvement store, represented a real challenge in the planning and conception of the system. Fig. 1 The proposed and implemented plant concept (Fig. 1) consists of the following main components: • Compact filter system with integrated speedcontrolled extraction fan, consisting of 4 modules pre-assembled at the factory: • Sound insulated clean air chamber with exhaust fan (45 kW), • filter cell with filter bags cleaned with compressed air, • chip buffer container with automatically controlled discharging unit, • cladded substructure of the filter unit for the installation of the briquetting press. • Extraction pipework system, split into 4 groups. • Return air duct with broken filter bag detector and switching option to outgoing-air operation with fresh air intake. • Spark detection and extinguishing system. • Briquetting press type SHB 125. • Moving floor container for storing the briquettes. • Blow-in container for the collection of the excess chip material. • Pneumatic transport system for feeding the blow-in container with sound-insulated transport fan (11 kW). • Single-shaft shredder (18.5 kW) with swivel feed unit. • Electrical circuit for the entire system (including automatic slide control and speed control for the extraction fan and the pneumatic transport fan via frequency converter). The following should be noted with regard to the technical characteristics and advantages of the system: Energy efficiency By splitting the pipework system into 4 groups, the savings potential resulting from the different demand for extraction power can be fully exploited by a speed control of the fan. This functionality is particularly important because the machine utilization has been increased in stages and even at full utilization the individual machines have different operation performances. The pneumatic transport system in combination with the buffer capacity inside the filter unit makes a further, considerable contribution to saving electricity costs. The capacity of this buffer has been designed in such a way that the chips arising in a single shift can be stored inside the filter unit. Only for a short time they have to be conveyed into the injection container via the pneumatic transport circle line. This aspect is particularly important for the summer months when there is no heating load and the briquetting press therefore is not used. Quiet operation The exhaust fan is installed in the clean air chamber of the filter unit, which is lined with sound absorbing mats and contains a silencer on the exhaust side for further noise reduction. In addition, the transport fan was fitted with a sound absorbing cover. 28 No. 2 • June 2021
USER REPORT The noise emission of the filter unit and the transport fan is hardly perceptible, so that there were no problems with the home improvement store in the direct neighbourhood. Briquetting The chip material separated in the filter unit is primarily briquetted and used as fuel to heat the production hall. Below the filter unit, a room for the briquetting press was created by covering the supports with sheet metal panels, which is accessible via inspection doors. Fig. 2 The SHB 125 (Fig. 2) was selected from SPÄNEX’s extensive briquetting press range, which achieves an output of approx. 125 kg/h, corresponding to a material throughput of approx. 1 m 3 of chips per hour. The octagonal briquettes produced are conveyed via a transport rail to the moving floor container, which is fed via 3 filling stacks. The degree of filling is monitored by ultrasonic sensors. The briquetting press is equipped with an oil preheater due to its outdoor installation. In addition, an exchangeable wear protection was provided to extend the service life of the machine body. From the moving floor container, a newly purchased boiler plant is fed with an automatic feed grate firing system. The maximum heating capacity is 350 kW. Intelligent control technology The function package of the electric circuit also automatically ensures the correct material handling. During the heating period, briquettes are primarily produced from the separated chip material. For this, the briquetting press is fed via a rotary valve . If the separated chip material exceeds the throughput capacity of the briquetting press, the buffer volume of the filter system is used first. If the filling level in the filter reaches a maximum value, the pneumatic conveyor system is automatically activated and the excess chip material is blown into the chip container via a second rotary valve (explosion decoupling ) and the transport fan. The filling level of this container is also monitored by a filling level indicator. In the summer months, the chips are removed exclusively via the blow-in container Summary of the Management Board After almost one year of operation, the responsible head of operating technology at the Simmern site, is convinced of the performance and functionality of the plant as well as of the energysaving and low-noise mode of operation. He sums up the result of the new extraction system as follows: “The extraction and briquetting system supplied by SPÄNEX, which was tailored to our special conditions, functions excellently and fully meets our requirements“. www.spaenex.de Temporary living: Everything from a single source In the small town of Kenzingen in Baden, Christoph and Stephan Schmidt have built a modern, three-storey house just around the corner from their architectural office. The double pitch roof building with the petrol green plastered façade and the distinctive dormers stands out in the structurally homogeneous residential area without appearing dominant or even intrusive. However, an outside viewer will not suspect that something is entering this prestigious building that has so far been booming almost exclusively in large metropolises. Apartment house and temporary living concepts are booming in cities: With their range of small and tiny apartments, they are aimed at weekend commuters, professional nomads, and students who need comfortable, smoothly functioning living space for a limited time – without having to drag furniture or wait for the WiFi connection. You can now find it in South Baden. JopaJoma: A new brand sets standards With their new apartment house, the two brothers are transferring the urban recipe for success of Micro living into rural areas and, as operator and project developer, are also establishing a new brand: In JopaJoma, high-quality architecture, design-oriented interior design, and a mod- No. 2 • June 2021 29
