The autoclave unit is a powerful high-pressure cylindrical vessel made of steel. The autoclave unit is assembled from individual shell elements. The autoclave units are closed at both ends with lids. Autoclave units’ lids should be tight in order to provide the tightness of the product. Autoclave units can be closed with either one lid on one end (in this case, they are considered to be dead-end) or with two lids on both ends (in this case, they are considered to be open-end).
In the manufacturing of silicate bricks, blocks, and other products, one usually uses autoclave items up to 36 meters long, with different diameters (2, 2.4 m) and thick walls (up to 14-18 mm). Autoclave units can operate at pressures of 8-16 atmospheres.
Modern autoclave units are equipped with the quick-acting gate of bayonet type. In this case, there are teeth located around the lid. When the lid is put onto the autoclave unit’s flange, the teeth are located between the ledges. After turning the lid by the turning mechanism to an angle equal to half the teeth pitch, the latter get into the grooves on the projections, and the lid closes. In other types of locking mechanisms, there is a special ring that connects the lid to the autoclave unit.
In order to ensure tightness, there is a rubber gasket in autoclave units with bayonet gates. The rubber gasket is tightly pressed by the steel rings with the help of springs and rods.
The main construction elements of dead-end and open-end autoclave units:
- Autoclave unit lid;
- Unit for lifting and putting down the lid; 3. Safety valve;
- Autoclave unit body;
- Steam admission line;
- Steam release line;
- Condensation line.
The autoclave unit body is installed horizontally on foundation columns on roller supports in order to compensate for thermal alterations of its body. During installation, one of the supports should be left static and immobile.
There is a rail track inside the autoclave unit which is required for the movement of trolleys loaded with bricks or blocks.
Saturated and superheated steam, which is required for autoclave treatment of silicate bricks and blocks, is usually generated by our boiler room. In some cases, steam may flow from a central line. Steam from the central steam line flows through pipes to each of the autoclave units. To open-end autoclave units steam flows through the hole in the center of the vessel, however, in the case of a dead-end autoclave unit, it’s much more convenient to supply steam through a hole in a solid bottom. A distribution pipe with many holes is attached along the entire length of the autoclave unit along transport routes (rails). A separate line is used in order to transfer steam from one autoclave unit to another.
The surface of the autoclave units is covered with heat-insulating materials in order to reduce heat loss to the environment.
Modern autoclave units use jib cranes in order to raise and put down heavy lids. Such devices allow opening the lid while preserving a minimum distance of 1.5 meters between the autoclave units.
Autoclave units are pressure vessels, thus, they should comply with very strict quality requirements. One has to observe regulations for ensuring safety while working with them.