Research and development

It is a long step from the laboratory to a full-scale industrial process, and frequently one wants to test an idea with more industrial-like equipment than is possible with glassware. An idea is often loaded with uncertainty over its viability, and one may be reluctant to spend substantial assets on it. With pilot equipment that has been constructed by SIRRA, a planned process may be tested at a reasonable cost, before proceeding to a full-scale plant. SIRRA’s working approach involves continuous interaction with the client: if the need for change arises, any such changes can be carried out during the course of the trial. Occasionally, tests need to be made directly on a process stream in a mill, and the work has to be carried out on site. In such situations, the use of small process apparatus is expedient.

In research projects, SIRRA’s personnel can operate the equipment, either at SIRRA’s own facilities or in the form of fieldwork at a mill. Research projects can also be conducted in unison with the client, or the client can themselves operate the apparatus that has been constructed by SIRRA. SIRRA can also attend to the analyses, either through the work of its own personnel or in cooperation with one of its co-operators.

Research and consultancy tasks for the pulp industry

SIRRA has its origins in researching the pulp industry. Its sphere of activity has taken shape through long experience of - in particular - the recovery cycle of the pulp mill. The business owner’s background is presented on the next page. SIRRA has focused on practically applicable and useful development work. Common areas of work are:

  • The removal of non-process elements, such as potassium and chlorine
  • Balancing sodium and sulphur
  • Chemical savings
  • Discharging salts in the environment
  • Evaporator scaling and encrustation in various items of equipment
  • Handling soap

The aim of development projects is usually chemical saving, the improvement of cost efficiency, and a reduction of process disturbances or a reduction of environmental load. Frequently, the incentive is an obligation from the authorities that is either imposed, or is expected to come into force. Examples are NOx emissions, and probable forthcoming restrictions on the dissolution of recovery boiler fly ash and chlorine dioxide generator salt cake in waste water.

Research into the pulp industry: A micrograph of soap in partially polarised light.

Sodium sulphate crystals after purification in pilot crystalliser.


A sample of precipitate in pulp in the bleach line.

Problem situations

In the pulp industry, as with other chemical process industries, problem situations and disturbances occasionally occur. Scales are formed in the equipment, filters are choked up, and pipelines are clogged. Kurt Sirén has participated in such problem-solving since 1985.

Examples of development projects

Apparatus and settling experiment in a mill.

Settling equipment with sampling taps.

Experiment equipment constructed of:

Use in a mill.

Test apparatus, material transparent PVC

Feed tank for the process.