Fruit and vegetables ‘breathe’, a natural process in which oxygen is converted into CO2 (carbon dioxide). An increased CO2 level in a cold store ‘calms’ the fruit, but an excess will cause damage and must therefore be removed.
A CO2 adsorber, also known as a scrubber, removes carbon dioxide from cold stores, along with a small portion of the harmful ethylene present. The CO2 adsorber contains active carbon, which has the characteristic of adsorbing CO2 molecules (binding them to it). By efficiently transporting the air from the cold store, passing it over the active carbon and returning it to the cold store, the CO2 is effectively removed from the air in the store.
Besides a user-friendly control panel for setting the actions per cold store, the adsorber is equipped with an ‘adsorber lung’. This patented system guarantees absolute low oxygen operation which means that virtually no oxygen can enter the cold store. This ideal for storage under ULO and or DCA conditions.
A frequency-controlled ventilator reduces energy consumption to a minimum – an important benefit because an adsorber runs for the majority of the day. Every fruit and vegetable variety has its own CO2 production and maximum permitted CO2 value. For this reason, Besseling produces different capacities of adsorbers so that we can always supply a solution for your application.
By lowering the level of oxygen in the cold store, respiration is slowed down and the ‘metabolism’ of important nutrients in fruits and vegetables is reduced. The objective is to keep the oxygen level in a cold store as low as possible in order to maintain quality and delay the ageing process as much as possible. The reduction of the oxygen level in a cold store can be accelerated using a PSA (Pressure Swing Adsorption) nitrogen generator. A PSA generates pure nitrogen from normal ambient air which will be used to expel the oxygen from the cold store.
The Besseling PSA nitrogen generator consists of two vessels fitted with extremely high-quality CMS (carbon molecular sieve). A CMS is capable of adsorbing oxygen molecules for a particular length of time. When saturation is reached, the system automatically switches to the other vessel by means of valves. The saturated vessel is prepared for the next cycle by depressurizing it, after which the adsorbed oxygen molecules are released and purged. Thanks to this simple principle, the reliability and lifespan of the PSA nitrogen generator is extremely high.
All our PSA nitrogen generators are provided with filters and automatic drains so no fluid or oil can reach the CMS.
Besseling offers different capacities of PSA nitrogen generators. The capacity is determined depending on the volume and number of the cold stores.
Ethylene gas is produced by fruit and vegetables and accelerates the growth, development, ripening and ageing of the product. Some fruit varieties, for example kiwis, are extremely sensitive to ethylene. The Besseling ethylene converter quickly and easily removes this harmful ethylene gas. In this way, your products retain their ‘eternal youth’.
The ethylene converter consists of two columns, each with a heat storage medium, a catalyst, heating elements and one ventilator. In turns, cold store air is guided upwards and heated per column. The air then passes through the catalyst bed where the ethylene gas is broken down. Finally, the air flow passes through the second catalyst bed, where the remaining ethylene is broken down and the air cooled back down.
With the Besseling ethylene converter, an ethylene level of 1 ppb (0.0000001%) can be achieved without making use of chemicals. This makes the process extremely environmentally-friendly. Thanks to heat recovery and accurate control of the optimum temperature, the converter consumes minimal energy.
Measuring is knowing! Without accurate measurement and the appropriate control of the equipment, all kinds of things can go wrong. Besseling has developed its own measurement and control system (ACS – Atmosphere Control Station) which can be used to control your cold storage facility fully automatic. You only need to set the required values and the system will measure, control and maintain your chosen atmosphere.
Quality and reliability at the heart of your system are extremely important! As such, the sensors approved by Besseling meet four important requirements; sustainability, stability, accuracy and response time.
ACS can easily be expanded with the addition of a cooling module that allows any type of cooling system to be managed. It controls the cooling valves, defrost valves and ventilators, based on target values which you can set yourself. Besides temperature, relative humidity can also be measured and regulated, as can the quantity of defrost water, if required. Thanks to this total concept, ACS is capable to control your entire cold storage facility.
The analysis system can be connected to a PC with BatNetWin Software. In this way settings can easily be changed and the measured data are stored automatically. The registered data can be graphically displayed and printed, making it possible to generate various reports and, for example, compare different time frames.
Besseling also supplies portable measuring equipment for manual measurement of O2 and CO2values.
During the holding stage in a cold store room most of the defrost water that comes a coil has been drawn from the fruit. Since you returns on your harvest are based on weight and quality there is an advantage to keep the dehydration of the fruit to the lowest possible minimum.
The Besseling defrost water recorders are an automated system to keep track of the amount of defrost water being drained away. This will be provide key information to determine the effect of changes in the refrigeration settings. The system is operated by compressed air and therefor is very reliable in operation. The data is displayed at your desktop computer screen for your convenience.
During a storage season, a cold storage facility is constantly exposed to changing conditions that can directly affect the atmospheric conditions inside. Besseling offers solutions for optimum protection and security.