Razem hints and tips

1 When is the cartridge for liquid methyl bromide degassed? - A gassing cartridge (one which is not filled by sorbing material), when placed in the oven, will warm up asymmetrically. Where liquid gas is in contact with the cartridge (bottom) the cylinder will remain cold until all liquid has been evaporated. This is a normal physical behavior. Consequently the cartridge will bend lightly as the top of the cylinder will expand while the bottom will not until all liquid is evaporated and bottom and top temperatures will become equal. It means that the gassing cartridge will be released by the oven as soon it is free from liquid gas. To end the gassing cycle the cart ridge and the liquid gas circuits can be flushed by fresh air delivered by the air compressor. Keep the gas bottle closed during this operation.

2 How to achieve faster gassing of a premise - You can reduce the gassing time dramatically with up to 75% (from ¾ of an hour to 15 min and less depending on the load of the cartridge) by turning the gassing cartridge regularly to the left or the right to bring the liquid methyl bromide in contact with the hotter part of the cylinder. Operating the cartridge in this way should be started early after heating up the oven and before the cartridge has been blocked in the oven by the temperature differences. BE SURE ALL CONNECTIONS ARE OPEN TO ALLOW THE GAS TO ESCAPE INTO THE PREMISE TO AVOID OVERPRESSURE IN THE CARTRIDGE.

3 How to degas a RAZEM-C cartridge faster and better - To degas a RAZEM-C cartridge faster you should flush it a first time by compressed air when the temperature of the oven reaches 100°C. Therefore it is advised to flush until the air compressor vessel is empty. This stage is reached when the compressor starts running AND the vessel manometer is at its lowest level. Stop then the flushing sequence and let the air compressor rebuild its vessel content (compressor shuts down). Once the compressor cycle is completed the dryer is functioning properly and the air contained in the vessel is dry and ready to flush the cartridge at 130°C (it is not necessary to heat over 150°C). If the compressor restarts to level up the vessel content, the added air will be dry too. DO NOT try to heat over 180°C as the oven could be damaged. Working with insufficient dry air will load the RAZEM-C with moisture which reduces its sorption capacity for methyl bromide.