Tech Drying ZQ conventional timber drying kiln

Tech Drying describes the ZQ series as a general-purpose lumber dryer for temperatures up to 100 °C. The frame is 6063 aluminium alloy, and wall, roof and door sheets are 3003 aluminium alloy fixed with 304 stainless-steel screws; a stainless-steel interior is available as an option.

The kiln has six systems: heating, spraying (humidification), air circulation, venting, doors and automatic control. Heat-exchanger base pipes, in-kiln pipework and connections are 304 stainless steel, and the steam system is rated for up to 1.27 MPa. Reversible aluminium fans with baffles push air through the stacks, and the motors are built for a 100 °C, 100 % relative-humidity chamber, with external motors available.

The 10–200 m³ range covers a family of chambers. Ask which chamber size is proposed for your project and whether the figure means the empty chamber or the timber it holds. Net volume depends on board thickness, sticker thickness and stack size, so two suppliers quoting the same capacity can deliver very different amounts of dry timber per charge.

The 100 °C limit makes this a conventional kiln. Tech Drying sells high-temperature hardwood drying and thermal modification as separate lines; if you need either, ask for that line's specification.

Steam, hot water, thermal oil and electricity are alternatives, and an offer covers one of them. The 1.27 MPa rating applies to steam heating. For hot water or thermal oil, ask for the design supply and return temperatures; for electric heating, ask for the installed load and supply requirement.

The controller holds temperature and humidity to within ±0.5 °C. It reads two equilibrium moisture content points, two temperature points and six to twelve wood moisture probes, runs drying cycles of more than ten stages, stores user programmes and offers touch-screen operation with remote monitoring from a phone or PC.

For your order, ask how many moisture probes come with the chamber size offered, where they are placed in the stacks, and how readings are recorded and exported. Check that the controller screens and manuals are available in your operators' language and how remote access is secured.

The best guide is a documented charge of timber like yours: species, thickness, starting and final moisture content, cycle time and the defects found afterwards. Ask whether Tech Drying has such records from a reference site and whether you can speak to that user.

If there is no close reference, write the acceptance test into the contract: how final moisture is sampled across the charge, the acceptable spread between wettest and driest boards, how checking and warping are judged, and who runs the first commissioning charge. Check the same boards again after thickness planing: moisture differences that survive the kiln show up as cupping and uneven removal, for example on a double-sided planer.

Give the species, board thickness, lengths, starting and target moisture content and weekly volume. State the heat source and its spare capacity, the site and the climate. Ask for chamber size, net charge volume, sample schedule, expected cycle time, an itemised offer and the general arrangement drawing, and confirm what you must provide on site.

• Chamber dimensions, and gross and net volume per charge
• Heating medium, heat demand and the heat plant included
• Number and placement of moisture probes, and data export
• Drying schedule and the final-moisture acceptance method
• ISO 9001 and CE certificate copies