GrainPro G-HF Cocoons^™

GAS-HERMETIC FUMIGATION

Sizes are identical to standard GrainPro Cocoons™. Designed for toxic-free fumigation and the safe storage of high value, durable, agricultural commodities. They are tailor-made to encompass stacks of boxed, crated or packaged product with a specially developed plastic liner that embraces qualities of durability, elasticity, tear strength, resistance to rodent penetration, and low to zero permeability to oxygen, carbon dioxide and moisture.

The Fumigation Principle:

The commodity is loaded into a gas tight flexible PVC, G-HF Cocoon™. Once the G-HF Cocoon™ is closed with the special gas tight zipper, CO₂ is flushed into the G-HF Cocoon™. Insertion of the gas will take place at the bottom gas inlet, whereas the top outlet enables the release of the lighter ambient air. The amount of CO₂ inserted should reach a concentration of 80%. This initial concentration will kill all living insects, larvae and eggs within an exposure time of maximum 14 days. As a rule, CO₂ is more effective at higher temperatures than at lower temperatures. The concentration of the CO₂ can be easily controlled with a portable O₂ meter. This technology fits most situations where methylbromide and/or phostoxine are excluded from use as fumigants for environmental or health-food reasons.

The Storage Principle:

All the agricultural products or their derivatives targeted for this storage system have prolonged shelf life due to their low moisture contents. However, under normal storage conditions they are all susceptible to damage and quality deterioration by stored product insects. Furthermore, many of the products are subject to oxidative changes during storage that have an adverse effect on colour, taste or nutritive value. In contrast, storage under modified atmospheres whereby the oxygen in the air surrounding the commodity is replaced by either carbon dioxide or nitrogen, prevents both the development of insects and oxidative processes within the commodity.

The System:

The fumigation modules have the same dimension as that of the standard GrainPro Cocoon™.

The method of applying the modified atmosphere is termed flush and maintenance method: G-HF Cocoons™ have a built-in gas inlet welded to the bottom and a 6” diameter outlet cap at the top opposite the inlet. Each Cocoon is provided with a high pressure hose of 2 m length, enabling handling of liquid CO₂ from an inverted standard cylinder without pressure regulator in order to “flush” the O₂ rapidly. In order to be able to determine CO₂ concentration, use of a CO₂ or O₂ analyzer is necessary. The “flush” method is designed for those cases where “fumigation” (total kill of all insect life in the commodity) is the purpose. In cases where long term storage of a commodity is required under low O₂ conditions, the CO₂ level has to be maintained by means of a slightly more complicated set up. In those cases, a cylinder with a pressure regulator, heating device (to prevent ice clogging when the liquid is turned into gas) and a solenoid valve linked to a control box regulating the preset gas level, dispenses gas into the Cocoon whenever the level of the gas goes beyond the preset limit. The schematic set up is as follows:

In order to be effective, treatment has to take place at temperatures of at least 25^o C.

The Advantages:

Advantages of storage under modified atmospheres are:

• The commodity is not subjected to periodic insecticidal treatments with toxic chemicals during storage to control stored product pests;
• The product can be stored at ambient temperature instead of the alternative energy consuming cold storage methods where sub-zero temperatures are required to prevent insect infestations and biochemical deterioration.
• Installation demands little infrastructure.
• Construction can be performed within a few hours.
• Cost effective compared to any other forms of storage.
• Commodities stored preserve a high quality level.
• Complete turn key projects, including design, construction and operation

Potential commodities and applications:

• Dried fruits as raisins, prunes, apples, mango, dates, figs, bananas, etc.
• All varieties of nuts
• Seeds
• Organic grains and beans
• Coffee and cocoa beans
• Tobacco leaves
• Dried vegetables as chili, garlic
• Dried flowers
• Fumigation for Museums, Libraries and Antiques
• Dried fish