Biotechnology Park Stráž
Biotechnology Park Stráž
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Biotechnology Park Stráž
Biotechnology Park Stráž represents the main facility of CoE LignoSilva. Flagship infrastructure – 3D CT scanning line is located here, as well as other important technologies
The Biotechnology Park Stráž (BTP Straz) has been managed by the National Forest Centre (NLC) since the 1960s. It is an area of approximately 5.6 hectares (Fig. 1). The area was gradually developed for large-scale cultivation of forest tree seedlings. Various types of cultivation plots were built, and several greenhouses were operated. The technology at that time was highly automated. In the 1970s, three production halls were constructed, where seeds were stored in air-conditioned spaces and forest cableway tracks were manufactured. The area underwent reconstruction in 1996, focusing on modernising heating and fire safety. The described production continued until 2003. After production ended, the area was minimally used, with minimal maintenance work. The area includes an oak forest of exceptional quality in terms of height, diameter, and straightness of the trees. The National Forestry Centre is again investing in the area and revitalising its functions to meet today’s research and development needs in the forest-based sector.
The completed integrated infrastructure of LignoSilva, in connection with the center’s scientific research program, forms the basis for creating innovative and research-development partnerships and consortia across the entire forestry-based and pulp-paper complex, as well as in related areas of technological, informational, and software solutions. The project brings the creation of model and prototype workplaces and key technological units for research and demonstration purposes in the areas of wood production, wood quality detection, and energy and pulp-paper wood processing. A significant output is also creating a data and knowledge base necessary for transforming the forest-based complex towards a bioeconomy and knowledge economy.
Significant investment is made in building key infrastructure units, such as a demonstration CT scanning line for wood logs, a dryer for forest fuel chips, and a RICHEL-type greenhouse, as part of the implementation of infrastructure projects.
The workplace has a 3D CT scanning line for wood logs, which includes a unique computer tomography technology. This technology allows for creating a three-dimensional model of each wood log and visualising its internal defects. This model is then used to optimise cutting plans to maximise yield. Currently, 14 CT scanners for wood logs are installed worldwide, and our 15th scanner is operated in a research and development environment, serving as a tool to increase the competitiveness of the forest-based sector.
In the computed tomography of wood logs, it is necessary to use spiral tomography technology. The scanning process involves the scanned object being smoothly inserted into a rotating ring, where a radiation source is placed on one side and a system of detectors on the other. Through computer processing, each point in the space is assigned a corresponding radiation absorption value in the given slice. Based on the absorption values, this value is converted into an image in shades of gray. The obtained data is used to reconstruct slices in the required planes.
3D CT scanning line
Table 1. Parameters of the 3D CT scanning line of logs
| Názov zariadenia | CT LOG Solution |
| Producer | Microtec |
| Operating temperature | -30 °C until 45 °C |
| Humidity | < 80 % rel. |
| Dimensions d/w/h | 24 300 mm /2 300mm /2 896 mm |
| Species of scanned wood | spruce, fir, oak |
| The length of the scanned log | from 1 500 mm to 10 000 mm |
| Maximum log diameter | 750 mm softwood/ 650 hardwood |
| Maximum scanning speed | 5 m/s |
| Source of radiation | X-ray lamp |
| Type of radiation | X-ray |
| Maximum voltage rtg. lamps | 225 kV |
| Maximum power | 3 kW |
| Maximum current | 15 mA |
| Radiation dose equivalent | 10 µSv/ h |
The log’s 3D model is reconstructed from CT images, which the CT scanner performs as cross-sections composed of voxels with dimensions of 1 mm x 1 mm x 10 mm. This means that a log, 4000 mm long, comprises 400 images representing individual slices.
The brightness value of a voxel in the black-and-white spectrum (greyscale levels), known as the DN value in the CT image, represents the attenuation of X-ray radiation, which depends on the amount of absorbed X-ray energy. In the case of lower material density, the voxels are represented by a lower brightness value (displayed as darker shades of grey) in the CT image, and vice versa. The density of the wood in the cross-section of the log shows significant changes depending on the structure of the annual rings and the presence of defects such as knots, cracks, and rot.
The following figure is a selection of such CT images that show examples of the internal features of oak wood. Image A shows healthy knots in an oak log, image B shows the difference between sapwood and heartwood in an oak log, image C shows cracks in an oak log, image D shows rot in an oak log, image E shows an unhealthy knot in an oak log, and image F shows the presence of metal in an oak log.
The workplace primarily focuses on finding ways to optimally use data from the CT scanning process of logs. The scope of activity can be defined as the area of luxury wood products made from valuable hardwoods. We use and apply artificial intelligence technology by training neural networks to detect and classify internal wood features automatically. The outputs from the trained neural networks are installed into our software, which is then used and improved in the production process.
The data processed from CT scanning is used to automatically burn splitting and cutting plans onto the log ends, to automatically split and cut logs, and to automate the sorting and stacking of wood products.
An important activity is also organising auctions with valuable hardwood logs, where we can offer potential buyers information about the wood’s internal defects. This is related to the service of log quality certification based on detecting internal defects.
Currently, 4 full-time employees are working on the premises.
This part of the area is equipped with free planting plots with fully automated irrigation and a fully automated Richel-type greenhouse.
This greenhouse is a proven and robust model designed for climatic conditions with an average amount of precipitation. The greenhouse is single-span with a width of 9.6 meters and a length of 50 meters, consisting of 20 sections. The perimeter structures are made of double-inflated foil. The interior space is not divided by partition walls. The total built-up area is 491 m². The main entrance is located on the eastern side of the existing site road. Another equally large gate is on the other, western side. The greenhouse is designed according to the EN 13031-1 standard, approved for direct use as STN and announced in the ÚNMS SR bulletin no. 11/02 – Greenhouses, Annex I Greenhouses – Dimensions and Construction. The outdoor cultivation area is next to the greenhouse on the northern side. The surface of the area is the same as that of the adjacent greenhouse. In the middle is a rail track with plastic sleepers for the irrigation ramp. The building is connected to the electricity distribution network using the existing connection. Water from the existing well will be used for irrigation.
Seedlings are grown in the plastic greenhouse and the outdoor growing area. We assume that Quick Pot plastic growing containers are placed on plastic or wooden pallets. This proven method is popular worldwide. An irrigation ramp is used for irrigation in the plastic greenhouse. An irrigation ramp with a trolley with brackets is used on the outer surface, which moves on rails. The plastic greenhouse is equipped with ventilation, which is controlled by a computer system.
The technology comprises a wood chip dryer opposite the lower hall’s southern facade. The dryer consists of the dryer itself, which is mounted on a foundation structure that includes retaining walls. In addition to the dryer, it provides conveyor belts for feeding wet wood chips to the dryer and dispatching dried wood chips to the storage tank. An auxiliary steel structure is used to store the conveyor above the belts. In addition to the conveyors, the drying room includes a ventilation chimney for hot air that is created during drying. The heated water used for drying is prepared in a gas boiler in the lower hall’s former technical room. The primary energy source will be liquefied natural gas – propane. The gas tank for the boiler room will be located at the rear of the premises.
Wood chips are brought to the site by trucks and unloaded on a free surface. Landfilling will be carried out only up to the height of direct dumping from the car, i.e., max—1.4 m. Chips prepared for drying are filled into a hopper using the tip loader, which a conveyor gradually transports to the drying process. The dried wood chips are collected in a steel-covered container and taken away using a particular truck.
Parameters of the fuel wood chip dryer – Belt wood chip dryer with an electronically controlled system. The dryer includes a hot water heat exchanger. Dried product wood chips of minimum fraction G50. Hourly input capacity min. 0.4 t/h. Hourly output capacity min. 0.2 t/h. Input humidity of wood chips max. 50%. Output humidity min 12%. Drying temperature min. 70°C. Drying surface min. 7 m2. Required heat max 300 kW at +10°C (ambient temperature), max 350 kW at -10°C. It also includes a wood chip container with an input and an output conveyor with a steel hook container that can be closed with a sheet of at least 9 m3.
Long-term research on-chip storage and the impact of storage on the presence of biological degradation is also ongoing at the workplace. Chemical preparations are applied to the stored piles of chips, and their effect on slowing down degradation is regularly tested by taking samples and subsequent testing in the laboratory. At the same time, data on the weather conditions at the station are recorded using the meteorological station.
BTP Stráže with greenhouse and outdoor nursery facility for production of container and bare-root seedlings and planting stock of woody plants for agro-forestry and forestry purposes. In the greenhouse, while applying wood ash and cellulose sludge to peat in different variants, we monitored different parameters on seedlings, such as the vitality and phenology of the initial development of the seedling, height and thickness increase and the health status. We also have a variant with only pure peat as a control sample.
Seedlings grown in containers with different concentrations of peat + ash/sludge
Wood ash and pulp sludge are applied to produce bare root reproductive material, demonstrated on planted seedlings in an outdoor nursery. Ash and sludge are applied to the soil in different proportions, and then the height and thickness increase and the phenology and health status of the transplant are monitored.
Bare root material in the outdoor nursery with different amounts of ash/sludge added
Bare root material in the outdoor nursery with different amounts of ash/sludge added
Seed Testing Laboratory for testing the technical quality of seeds, including their germination and, eventually, tolerance and phytotoxicity levels in emerging seeds and seedlings of forest tree species. The laboratory is accredited under the International Seed Testing Association ISTA and ISO.
The seeds of the monitored species are watered with leachates of different mixing variants and concentrations of peat, wood ash, and cellulose sludge. Subsequently, the samples are stored in a germination box where we can simulate periods of night and day with different temperatures. During the entire process in the germination boxes, the seeds’ health status, germination, and germination energy are monitored.
Measurement of germination and germination energy in germination boxes
For the overloading of the infrastructure mentioned above, to ensure its operation and safety, investments are made in building new or renovating the original supporting infrastructure. This involves the reconstruction of the water source (drilled well), the rebuilding of the transformer station to cover electricity consumption, the construction of gas storage tanks, the construction of a fire tank and fire water supply, the reconstruction of area lighting and the reconstruction of the lower hall to create a working environment. The hall’s building is designed to modernise the existing building by creating two tracts. One tract will be used for administrative purposes and conferences. The second tract will be equipped with technology for research purposes.
Biotechnology Park Stráž is fully equipped to organise workshops, project meetings, conferences, seminars, and various trainings. The meeting room has a capacity of 50 people and is equipped with the most modern technology for holding online meetings.
The first fully electric telescoping loader in Slovakia was used for handling logs in the CT scanning process, working in more cultivated areas, and general maintenance of the area.
