SU50480A1 - Form for pressing building boards - Google Patents

Description

When pressing products from crushed raw materials, subsequent drying is required in most cases; in this case, the drying can be carried out in the usual way and leaving the products in the forms in order to avoid disturbing the design given to them.

Products that are molded from liquefied masses are usually dried on special mesh shelves open with a very high content of remaining moisture, which is extremely expensive and lengthens drying.

If the mass is used in an air-dry state, then to obtain from it a sufficiently dense and mechanically strong product that would not lose its shape when drying, such products must be dried without being removed from the forms. In this case, the amount of evaporated water is many times reduced, as is the cost of fuel, but the number of products is often lower. In order to obtain normal mass cohesion in products, increased quantities of raw materials must be taken and, giving greater pressure, reconcile with increased volumetric weight and flow.

raw materials. In addition, drying in conventional forms, having free exits for steam, rapidly occurs around the periphery and therefore warming up is slowing down in the middle and drying is delayed. As with drying without forms, due to the rapid formation of a dry outer crust and the access of oxygen to the air inside the molds of a conventional design, it can be even dangerous to speed up the drying by using particularly high temperatures in the first half of the drying process.

For these reasons, both existing methods of molding and day products from both wet mass and air-dry have major drawbacks, not only in terms of their cost-effectiveness, but also on the technological side. In order for the drying to take place, if the mass was at the possible equal external influences and that the heating of the mass was more uniform, fast drying from the surface is undesirable.

It is necessary to begin with warming up the dried object in all its layers, for which it is advantageous to use the available moisture, which (being turned into steam) must, before going out, steam the whole mass and equalize the temperature at all points of the dried object.

The present invention has in mind the implementation of accelerated drying of articles in a press form by heating and steaming in a hermetically sealed space. For this, the lower part of the heated mold is provided with liquid chutes, into which the lower edge of the sides of the upper movable part of the mold is immersed, forming a hydraulic lock.

In the schematic drawing of FIG. 1 shows a vertical section of a mold with a raised upper part, and FIG. 2 is the same when lowered.

The press form consists of two plates heated with steam or electricity, of which the bottom is n-fixed, and the top can be lifted and lowered under the action of a screw or piston of the hydraulic press to bring the mass placed in the form to the desired compression limit from the bottom.

The bottom plate is surrounded by a lightly movable casing tightly covering it, serving as flanges for the compressible mass placed on the bottom plate. To the bottom plate is tightly attaching a Y / C trough on all sides that can hold any liquid X.

A closed side b is attached to the top plate on the sides, the width of which is calculated to cover the cage after the top plate c is lowered. In the upper part of the bead, b have a thickening y, which plays the role of a stiffener, to overcome the arching effect of the compressible mass and the heat insulating lining, which has the purpose to reduce losses through the unheated end parts of the pressed product. In addition, two holes are provided in the top plate, through which, in case of a sticking of a dried object (plate), it can be pushed out. These openings, closable with stoppers, can also be used to release air vapor.

The mold is intended to compress the mass of that small initial moisture content at which no water is squeezed under pressure under any pressure.

After the ccc top plate is raised, the holder is set at the desired height and a compressible mass is applied to it.

When the mass is laid, the top plate is lowered, and the sides are passed over the wall {And the walls of the holder, which, after contact with the top plate, also lowers until the mass m is compressed to the required compaction and reaches the specified thickness (Fig. 2 ). When lowering the upper plate into its boards b at a known level, it is immersed in liquid X, as a result of which the pressed mass will be hermetically closed from access to it.

in the hell of air.

The ongoing heating of the compacted mass from the press plates,

having a temperature in excess of 100 °,

at first, there is no loss of moisture, because in closed form the liquid is poured into the tolk and plays the role of a hydraulic shutter; at the same time, the mass is steamed (due to the moisture that is in it) until such time as the formed inside the pair will not acquire some voltage sufficient to overcome the back pressure of the liquid column in the zhol and go out

To prolong the steaming time, to reduce the heat inflow, and, if desired, to accelerate steam stripping for drying and heat treatment of the product, it remains to continue heating and even increase

heat supply without fear of fire, which, in the absence of air

difficult.

Drying is accelerated by the evaporation of water instead of evaporation occurring from the surface and accompanied by the formation of a crust on the outside, which delays the warming up of the dried object

inner layers

By choosing the type of fluid with the appropriate volumetric weight (for example, mercury) and changing the height of the level of this fluid in the chute, you can achieve various counter-pressures and the associated propelling temperatures.

The subject matter of the invention.

The form for pressing the construction plates, consisting of two heated parts, the upper movable and the lower stationary, equipped with side boards, characterized in that the bottom part of the form is attached to it to form a hermetically closed space during heating and steaming of the material embedded in the form the liquid gutters, in which the lower edge of the side b of the movable part of the mold is immersed, form a hydraulic lock.

FIG.

FIG. 2