METHOD AND DEVICE FOR PREPARATION OF NITROGEN PASTE Russian patent published in 2009 - IPC C01B21/04 B01J3/00 F25J1/00 

FIELD: chemistry.

SUBSTANCE: method for preparation of nitrogen paste includes using of the liquid nitrogen tank whereat the liquid nitrogen is placed at decreased pressure beforehand; vacuum pump for pressure reducing inside the tank; vessel under reduced pressure for preparation of nitrogen paste whereat the reduced pressure is maintained with vacuum pump; sprayer located in the vessel under reduced pressure and intended for injection of the liquid nitrogen fed from the tank. The sprayer diametre and spraying pressure are adjusted to support the liquid nitrogen state in the form of the drops. The said method also includes: liquid nitrogen spraying in such a way that fine-dispersed liquid nitrogen particles with equal size are formed and dispersed to the vessel; nitrogen evaporation from the drops in order to transform it to solid state due to the latent heat of vaporisation and to form the solid nitrogen particles with equal size; mixing of the liquid and solid nitrogen particles with mixer located in the vessel bottom. The device for implementation of the above method is claimed as well as modification of the method providing the usage of several devices connected in parallel.

EFFECT: presented method is inexpensive and allows preparing of the nitrogen sludge with good flow-ability and equal particle size without using the inert gas cooling.

5 cl, 2 dwg