Something big often starts with something quite small. Take August Gronert, a clever inventor who, in 1935, applied for a patent on a dew-making machine for greenhouses. This invention was the start of a very successful company, which went on to file another 56 patents. In this blog, I explain how it all started for Gronert with the dew-making machine.
The dew making machine explained
Some plants need dew to thrive, just as in nature. This dew has to collect on the underside of the leaves.
To achieve this, Gronert came up with the following set-up: a cultivation box (a) filled with soil (b) containing plants (c), with a heating pipe (d) hanging alongside it. The heating pipe (d) is embedded in a water-absorbing casing (e). When the heating pipe (d) heats up, moisture in the casing (e) evaporates.
Above the box (a) is a guiding surface (f) that directs the water vapour past the plants (c). To stop the vapour condensing on the guiding surface (f), it is made from a poor heat conductor. Cold air also circulates over the top of the guiding surface (f). This cools the air in the crop room. And voilà, you have dew.
The beginning of something bigger
Gronert then applied his knowledge of moisture to other areas, such as drying harvested potatoes and grain. His greatest success was the gravimetric moisture analyser: essentially a set of scales with a fold-down heater above it. This meant samples could be weighed before and after drying without a separate oven.
He founded the company Ultra X to make it, and applied for patents in the world’s most important markets. Ultra X analysers are still made today, by a&p instruments. Gronert would have been proud that his granddaughter now leads technical development there.
Competition
Now back to the dew making machine. When I delved into the old patent, it was still unclear to me which plants Gronert actually needed a dew making machine for. The only example mentioned in the patent is mushrooms. Which other plants do better with dew as opposed to dripping or misting? I even asked ChatGPT, but that didn't really get me anywhere. I wonder if anyone knows which other greenhouse crops dew might be important enough for to start using Gronert's invention commercially in a greenhouse? I want to invite you to speculate and let me know what you think.
