Compact 
filter system

The Latvijas Finieris group is the leading plywood producer in the Baltic States. As a part of this group, SIA TROJA in Riga produces furniture and ceiling and wall coverings from plywood panels.

In 2019, the company moved to a new production site in Riga, where a total of 9 CNC machining centres will work in 3-shift operation in the final stage of development. The implementation of this project is to take place in 2 steps, whereby in the first step, in addition to 4 CNC machines, also dividing saws, sliding table saws and a press are to be dedusted. The required volume flow is 40,000 m³/h. In the second step 5 further CNC machines with an additional volume flow of also approx. 40,000 m³/h will be added.

The pipeline network and filter capacity should be planned in such a way that the filter system is already fully functional in the first expansion stage and the necessary filter capacity for the second stage can be added as easily as possible.

Therefore SPÄNEX and its local partner, the company Infleks from Riga, proposed a filter plant of the compact series (figure 1). The filter plant represents a compact unit, which is composed of 4 modules:

• The soundproof fan cell with built-in radial fan,

• the filter cell with filter bags, cleaned by compressed air,

• the chip buffer container with automatically controlled discharging and

• the covered base of the filter unit for the installation of the briquetting press.

The covered base of the filter unit is accessible via inspection doors, so that maintenance works on the briquetting press and the container discharging can be carried out without any problems.

The most extensive pre-assembly of the compact filter system in our plant in Uslar limited the on-site installation time to only 2 weeks.

From the extensive briquetting press programme of SPÄNEX a suitable machine (figure 2) has been selected, which can briquette a chip volume of approx. 1 m³/h. The octagonal briquettes are conveyed back into the building by a transport rail and packed for selling.

Troja attaches great importance to a high availability of the system and, as an alternative to the briquetting press, wanted the option of disposing the chips in a separate container via an additional screw conveyor (see also fig. 1).

Within the cooperation of SPÄNEX and Infleks, the entire extraction duct system was provided by Infleks and installed at the same time.

In the second stage of expansion, the new CNC machines are dedusted via a separate pipe system, which is connected to a further, identically constructed compact filter system. The chips separated here are pneumatically conveyed into the directly adjacent first filter unit.

Both filter systems have separate return-air ducts, which are arranged in parallel and fed back into the hall.

In the event of a malfunction or maintenance, one of the two systems can always continue to operate, so that no interruption in production is necessary.

The function package of the electric circuit automatically ensures a safe and controlled operation of the extraction and briquetting system. For quick support of the operating personnel, the electrical circuit has a remote maintenance module. With this module the specialists in Uslar can call up all parameters via the PLC-based control system from Riga and, if requested, provide immediate information for optimising the operation parameters.

This project has shown that the cooperation with Infleks as a local partner of SPÄNEX works excellently and offers the Latvian customers the certainty that their ideas and wishes will be taken up and implemented at short notice and without language barriers.