Bricks

When a furnace lining is constructed in brick the lining thickness is usually designed so that the structure will be self-supporting. For vertical walls this means that either the wall gets thinner as it gets higher or supporting shelf brackets are used at regular intervals to break the height up into sections. These sections then allow expansion joints to be provided so that as the structure heats up it has room to expand and does not bend in toward the hot furnace chamber. Similar expansion joints are needed in the horizontal direction to prevent bowing occurring in that direction as well.

Occasionally special bricks may be used which enable metallic fixings to be used to hold them back to a shell.

In some roof constructions, particularly where a flat section is required, alternate bricks may have this anchorage arrangement. More usually brick roofs will be arched and supported on skewbacks so that the whole arch is in compression. The thrust line must fall within the lining or failure will occur. Catenary arches are used in some cases where skewbacks are not suitable or where the mechanical properties of the brick at temperature are not strong enough to withstand the mechanical stress.

Castables and Gun mixes

Designs are generally in the shape of a "V" or "Y" and fixing is usually by welding although screwing through the shell or to a welded nut may be used. In some designs muliple simple "V"s may be mounted on a stalk to retain a greater thickness of lining. For some applications it may desirable to have an anchor which allows the lining to move a small distance away from or along the shell. A family of flexible anchors has been designed for these applications.

Plastic or Ram mixes

Although metal anchors may be used when materials are installed by ramming they need to be more robust than those used when casting or gunning is the installation method. Metal anchors for ramming installations will usually be of cast metal not rolled bar.

More usually anchors made of refractory material similar to dense refractory brick are used. The shape is the result of each manufacturer's experience and preference but in general they resemble square section brick with corrugated sides. The end facing the heat is often chamfered and the end facing the shell is shaped to sit in a retaining metal clip or on a bolt. The length of the anchor is fixed by the thickness of the wall or roof it is retaining. In some cases it is possible to extend an anchor with two others to allow very thick wall sections to be constructed.

Our experience stretches back many years and includes many techniques from most well known manufacturers and in most applications.

We will be pleased to advise you on any refractories associated problem.