Page 24 - february

METALWORKING EQUIPMENT AND TOOLS

The features of the fluidized bed
air into ventilation
system are its high heat capacity and thermal
sand
conductivity. Intense circulation of
particles, the volumetric heat capacity
of which is several orders of magnitude
higher than the volumetric heat capacity
of air, sometimes does not allow to
provide the required cooling rate, leads
to the lengthening of installations over
water
5-6 m and to an increase in their energy
consumption. Therefore, below are
sand two designs of combined cooling units
by combining two refrigerants - air
and water. Moreover, in the air, before
air from fan it comes into contact with the bulk
material, water is dosed (a water-air
Fig. 1. Installation of sand cooling in a fluidized bed. It consists of three sections
of the sectors: І - lower air, ІІ - middle cooling, ІІІ - upper separating: 1 - dispersion is created) in an amount that
pipeline, 2 - gates, 3 - pipes in the form of a coil, 4 - nozzles-mushrooms, 5 - does not interfere with the preservation
"chipping" grate.
of the flow ability of the sand.
Figure 2 shows an installation for cooling loose molding material, which is a welded metal
structure consisting of an inner water-cooled body 2 and an outer body 5, inside which are dust-
reflecting rings 3 and an air inlet 4 with conical screens at different levels. At the top of the inner
body, a mesh cap 1 is installed, which filters out large inclusions from the molding material.
The water-cooled body 2 is welded in the form of a pipe, to the upper part of which a conical
funnel is welded, and the lower wall is made flat. A number of vertical pipes are welded between
them. The inner part of the body is divided into
sections by partitions made of sheet material sand
to create turbulent flows of water washing the
pipes. The water supplied to the lower supply air to water
cyclone
pipe passes between the pipes and is discharged
through the upper side pipe.
Sand through the mesh 1 enters the funnel, water
is divided into streams and passes through water
numerous water-cooled pipes of the body 2. To
increase the path and duration of contact of hot air
bulk material with the walls of the pipes, spirals of
sheet material are inserted into them, serving as
a slime for sand. The step of the spiral is chosen
so that the sand rolls along them at an angle Fig. 2. Installation of cooling bulk molding material in a combined
exceeding the angle of its natural slope. Due to way. 1 - mesh hood, 2 - water-cooled body, 3 - dust-reflecting
rings, 4 - air inlet pipe, 5 - outer body.
the acquisition of the tangential component, the
24 Stanochniy park