Hall climate management for production of derived timber products

Leading companies in the wood-based panel industry already use the most up-to-date technologies for optimising processes, but despite this there are still many variables that can impair panel quality. The hall climate management concept designed by the Scheuch air and environmental engineering specialists provides a new constant that supports the production process in an energy-efficient manner, improves employee protection and increases operational safety.

Scheuch is a family-operated company working on an international level and is celebrating its 50th anniversary this year. With its “Wood Processing Industry”, “Wood Based Panel Industry”, “Metals Industry”, “Industrial Minerals” and “Energy Industry” divisions, Scheuch is a market and technological leader in many areas of air and environmental technology, whether with respect to extraction, conveyance, dedusting or flue gas purification.

Comprehenisve range for air and exhaust gas cleaning A significant amount of the company’s success can be attributed to its “Wood Based Panel Industry” division. Whether it is MDF, OSB, chipboard, hybrid or wood fibre insulating panels, Scheuch offers a comprehensive range of air and exhaust gas cleaning products for all areas of panel production.

The comprehensive product and service range covers everything from fans and cyclones to bag filters, dry and wet electrostatic precipitators (SENA, SEKA), as well as biological exhaust gas cleaning systems (e.g. SABA) through to exhaust gas scrubbers for press exhaust gases (e.g. SAP, ESAP) and fibre sifters. From consultation and project planning, production, assembly and commissioning right through to system services and emission measurement; Scheuch is able to offer everything from a single source.

Hall climate management concept

The company once again proved its innovative strength and customer focus with the new hall climate management concept “SPAC” (“Scheuch Plant Air Control”), which was unveiled at LIGNA 2013 in Hannover.

Scheuch developed this one-of-a-kind concept to give added value to traditional air and exhaust gas cleaning concepts, which guarantees its customers an optimal hall climate for panel production and minimises factors that impair production.

The hall climate management concept enables the main factors in the hall climate that influence ventilation in the production halls (in both new and old systems) to be regulated. The airflow rates extracted at the emitters must be specifically regulated. The concept precisely determines how much supply air must be applied to which position and the method to be used to condition the air. As part of this process, much of the return air cleaned by Scheuch filters can be reused – optimising the energy process.

A matter for experts

The concept is based on providing a targeted air flow (e.g. air supply system with energy recovery) and avoiding diffused air currents in the production hall. Parameters such as air temperature and content, such as dust or volatile organic components (e.g. formaldehyde), can be regulated in a controlled manner.

Achieving an influence of this nature requires knowledge in the production of wood-based materials and experience in supply air systems – areas in which Scheuch is unrivalled and where it is able to offer an overall package, which includes design and planning, technical solutions, as well as individual consultation services.

“Many aspects, such as energy, process technology and the production hall as a workplace, must be considered to achieve a balanced hall management concept in the wood-based panel industry. These aspects require a competent partner who recognises the complex interrelationships and can develop suitable solutions,” explains Köck.

Added value and advantages of the concept:

As added value, the Scheuch hall climate management concept provides an optimum hall climate for panel production in wood-based material factories, as well as the following advantages for the operator:

Support in the production process

There are many factors throughout the production process that can affect the quality of the end product. Stable production conditions are therefore fundamental for a production process to function well. The new hall climate management concept (SPAC) provides a new constant that helps to optimise the process (for example, a constant hall temperature that is adapted to the respective production stage).

Stable production conditions are achieved through optimum and constant heat input and air currents that are adjusted to the respective stage in the process. To this end, the hall is divided into three production areas:

Employee protection

In addition to stable production conditions, the hall climate management concept (SPAC) supports employee protection thanks to improved air quality and a lower concentration of workplaces. This is primarily due to exhaust gases from the presses being collected efficiently (see Scheuch SAP system) and a specially adapted air supply. Return air cleaned by Scheuch filter plants that comes from other production areas can be reused, as it is able to guarantee a residual dust content of < 0.1 mg/m3.

Operational safety

Exhaust gases from the press must also be safely collected directly at the press gap and diffused air currents from other areas must be avoided by means of a controlled air volume exchange. As recirculating the air while extracting water vapour from the presses is not technically viable, a higher, external and conditioned supply air flow is required. Practical applications of this confirm the many current simulations previously carried out (CFD analyses), which reveal that it is necessary to supply air in a targeted manner (for example, to avoid air short circuits).

Using energy efficiently

All thermal subprocesses that take place during panel production are analysed for their heat retention potential and are used to compensate the air flow balance for the individual areas in the production hall as part of the SPAC. In doing so, predominantly unused waste heat from the process is recycled. If there is insufficient energy potential, systems for generating hot air are also used.

A balanced hall climate management concept allows energy requirements to be optimised and prevents energy loss resulting from haphazardly exchanging warm air with cold air from outside, for example.

“The Scheuch hall climate management concept is a new constant that contributes to process optimisation taking existing energy potential into account and supports employee protection and operational safety,” emphasises Köck.

Image 1: SPAC overall concept for balanced hall climate management.

Image 2: CFD analysis V1-V2 – initial situationThe lines of the graphic illustrate the path that the air covered through the wood-based material production hall – from its entry to the extraction point. The colours show the different air currents where green and brown represent the controlled supply air. Additional uncontrolled supply air, which is represented by the red current lines, arises as there is negative pressure in the hall caused by unclosed doors or leaks, for example. Much of this uncontrolled supply air moves towards the middle of the hall. As a result, it cannot be ruled out that dirt particles will reach the press as a result of the current. This, however, must be avoided and is the objective of this simulation.

Image 3: CFD analysis V4-V5 – after optimisation This graphic displays the air currents that have already been optimised in the same hall with the same leaks. They are directed in a controlled and targeted manner. There is a clearly recognisable air curtain in the press area in the middle of the hall, which prevents the presses from becoming contaminated with foreign particles from neighbouring areas.