The series products are designed by making use of hand aspirated type ball (ZYB-5)or foot cylinder (ZYB-8), a little of liquid nitrogen inside is vaporized, the liquid nitrogen inside the container is pressurized due to the high gas/liquid ratio of liquid nitrogen, so as to release liquid nitrogen from container automatically. It is easily operated, reliable with features of safe releasing and lower vaporizing loss ratio. ZYB-8 is a patent product. And its patent number is ZL03 2 32947.4.