While many companies are reducing their kilning capacity, or cutting it altogether, Timber Dryers Ltd – a subsidiary of C Blumsom Ltd – has found its niche in rekilning.

In a £300,000 investment, the company has installed a new wood-fired, fully automated boiler and will be installing three kilns. The move was largely motivated by the need for boilers to comply with the new process guidance note PG1/12 but it gave Timber Dryers the opportunity to introduce state-of-the-art kilning facilities, including the capability to heat treat softwood packaging.

The boiler, supplied by Modern Energy Systems Ltd, can burn up to the 38 tonnes of woodwaste generated by Blumsom’s moulding plant each week and, producing 850kW of energy an hour, provides enough hot water to heat the kilns, the mill and more.

“We have so much spare heat that we’re offering it to warehouses in the area,” said managing director Robert Blumsom. “We have enough to heat the whole yard twice.”

The first of the kilns to be installed is a 5m3 facility, specifically designed to dry small batch loads of temperate hardwood for Blumsom. The two 30m3 capacity units, which will be installed by the spring, will be used for more of Blumsom’s work, as well as trade kilning. All the kilns are being provided by Kiln Services Ltd.

Maintaining a service

Although demand for trade kilning has declined as more is done abroad, Timber Dryers has maintained a service largely for specialist kilning. This usually involves redrying hardwood timber down to 8% moisture content (mc) or lower for flooring.

“We have been bringing a lot of oak in from Slovakia which is only air-dried so we kiln it,” said Mr Blumsom.

The company also kilns softwood and, again, it is a specialist service, taking the mc down to around 8-12% for furniture and flooring manufacturers.

Mr Blumsom said one of the market advantages of Timber Dryers’ trade kilning is that it is focused on giving a “very fast service”. “[The timber] won’t be lying around the yard for ages,” he said.

While the small kiln is a trolley-loaded system, the two larger kilns will be direct drive-in so no trolleys or track are needed. Each kiln will have a variable speed fan control, making them efficient for drying any species of temperate hardwood or softwood.

The kilns are claimed to be very easy to use. Linking with Kiln Services’ MP4032 central computer, the operator simply enters the species, the board thickness and the required final moisture content. Throughout the drying process the status of the timber is monitored automatically.

Oak program

Kiln Services managing director John Commons said the kilns are supplied with the latest program for drying thick oak.

“This program has a high conditioning phase built into the drying program that allows for timed periods of high humidity. This reduces the possibility of degrade that is sometimes caused when drying refractory hardwoods,” he said.

The three kilns will be connected to a high pressure humidification system that provides water at 1400psi to spray heads that produce minute water droplets of around 30 microns. These evaporate almost immediately, ensuring fast and accurate control of the equilibrium moisture conditions within the kiln.

The kilns are also designed to comply with the ISPM 15 requirements for heat treatment of softwood packaging, giving Timber Dryers the opportunity to diversify further.

A key focus of the investment has been improved efficiency, hence the installation of the highly automated new Weiss boiler which has enabled the operator who maintained the old steam boiler to be redeployed to fork lift and general plant maintenance.

The combustion system uses a unique water-cooled rotary screw grate that is programmed to transfer the fuel to an automatic ash extraction system. All the principal functions are automatically controlled to modulate a firing rate of between 40-100% of full load.

There is also an on-line connection to Weiss in Germany so problems can be rectified over a telephone modem link to the boiler’s computer control. The manufacturer may even be aware of a problem before Timber Dryers knows of it.