Food packaging machinery in several common abnormal phenomena
Food packaging machinery in several common abnormal phenomena. Vacuum packaging machine in packaging products is also a variety of different phenomena. At this point, from the top of the distribution plate to the outlet of the fluid, the entire container is filled with solid particles that collide and rub with each other less, but move at a net upward velocity. The bed also lost interface, and the rapid decline of the bed, the density of solid particles in the bed decreased, this state is also known as dilute fluidized bed. Bag feeding and packaging machine is a new type of automatic packaging machine.
Food packaging machinery in several common abnormal phenomena. Scattered fluidization and polyfluidization can be distinguished by F, F <1, scattered fluidization; F>, 1, poly fluidization. The solid particles disperse evenly and boil smoothly in the bed, which is an ideal fluidization. Poly type fluidized bed, the solid particles is not in the form of a single, but take the form of particle group, when the fluid is often in the form of bubbles rise through the bed layer, the bubble in the process of rising slowly grew up, merge each other or have a few broken, reach the bed layer interface is broken, bed pressure loss, the appearance of the bed like a boiling liquid.
Food packaging machinery in several common abnormal phenomena. Flow in the fluid pass into the fixed bed layer, due to various reasons make the uneven distribution of fluid in the bed, the bed layer of the parts of short circuit, make a considerable amount of fluid through the short circuit flow bed, even through the bed of air speed is greater than the critical velocity (vm, and the bed is not fluidization, the channel flow, through the middle channel flow and two. Typical characteristic curves of fluid velocity and pressure loss occur through the groove flow and the intermediate groove flow.
Food packaging machinery in several common abnormal phenomena. In the fluidized bed dryer, if the groove flow, will make dry media and dry material contact bad, drying efficiency is reduced. To eliminate the phenomenon of groove flow, it is generally necessary to use a larger velocity, reasonable design distribution plate, control the material not too wet, if necessary, can be installed in the bed stirring device, in the process operation, you can first air supply after adding materials.
Food packaging machinery in several common abnormal phenomena. Steam gas uneven distribution of solid particles in the fluidized bed size by non-uniform distribution board, or the height of the fluidized bed with larger diameter ratio, and so on and so forth, can make the bed inside the bubble together to grow up, until the bubble diameter is too big to close to the bed inside, because of its high gas velocity, solid particles in the bed can form the piston upward movement, when the bubble burst on the dense phase interface, the particles will be thrown up high, small particles entrained by airflow, and the larger particles are falling. Such reciprocating cycle, will make solid particles and dry medium fluid contact bad, drying efficiency reduced.