Measuring Device for Air Speed in Macroporous Media and Its Application Inside Apple Storage Bins

Abstract

In cold storage facilities of fruit and vegetables, airflow is necessary for heat removal. The design of storage facilities influences the air speed in the surrounding of the product. Therefore, knowledge about airflow next to the product is important to plan the layout of cold stores adapted to the requirements of the products. A new sensing device (ASL, Air speed logger) is developed for omnidirectional measurement of air speed between fruit or vegetables inside storage bins or in bulk. It consists of four interconnected plastic spheres with 80 mm diameter each, adapted to the size of apple fruit. In the free space between the spheres, silicon diodes are fixed for the airflow measurement based on a calorimetric principle. Battery and data logger are mounted inside the spheres. The device is calibrated in a wind tunnel in a measuring range of 0–1.3 m/s. Air speed measurements in fruit bulks on laboratory scale and in an industrial fruit store show air speeds in gaps between fruit with high stability at different airflow levels. Several devices can be placed between stored products for determination of the air speed distribution inside bulks or bin stacks in a storage room.

Developing of biophysical food for monitoring postharvest supply chains for avocado and potato and deploying of biophysical apple

“…The option for real-time monitoring would benefit, as stakeholders could directly see what is happening in the cold chains to take the proper actions. In the ideal case, the logger device could also include other relevant sensors (e.g., respiratory gases or air speed) (Geyer et al, 2018;Keshri et al, 2020). Note that in the current version, additionally to temperature, humidity can be measured by using a Hygrochron (DS1923) instead of a Thermochron (DS1921G and DS1922L) iButton at the surface.…”

“…Few studies have been conducted about novel fresh produce simulators monitoring temperature, humidity, or respiration (de Mello Vasconcelos et al, 2019;Geyer et al, 2018;Hübert and Lang, 2012;Keshri et al, 2020). A fruit simulator sensor device recently described by (Defraeye et al, 2017) was developed to monitor and analyze product temperature more realistically in order to improve storage and transport conditions in the cold chain.…”

Measurement of Water Vapor Condensation on Apple Surfaces during Controlled Atmosphere Storage

“…0.10 m above the fruit layer. An in-house developed omnidirectional air speed logger (ASL) (ATB, Potsdam, Germany) was used to measure air movement in close vicinity to the apples [ 33 ]. In the free airflow at some distance from the fruit stored in the top layer, the air velocity was measured using a FVAD TH4 thermoanemometer (Ahlborn, Holzkirchen, Germany).…”

Digital twin concepts for linking live sensor data with real-time models

“…Such sensor technologies have been developed in subsequent projects of the Intelligent Container. A sensor called "air speed logger" was developed to measure the omnidirectional air speed in apple bulk shipments (Geyer et al, 2018). It consists of four interconnected plastic spheres, each with 80 mm diameter, adapted to the size of an apple fruit.…”