Supported Brick

Figure 48-1 Corbel supported brick lined concrete chimney.

In this instance, brick was also used as a protective layer to shield the structural shell from the effects of heat. The flue itself was designed to stand alone against the forces of gravity and earthquake. An airspace was provided ranging from a few inches to a few feet, so that access could be provided to the exterior surface of the brick liner, a maintenance advantage not possible with the corbel supported brick lining. The structure itself was laid up in either acid resistant silicate or common Portland cement mortars, as previously described. It was basically unreinforced axially, but was corsetted with steel tension bands cir-... 

As stated earlier, acid resistant brick masonry (ARBM) has been a long standing workhorse in the industry. While the corbel supported brick liner has likely seen its last days with the passing of the hot, dry chimney, independent brick liners remain those most commonly specified today. 

To reduce this problem and reduce stress to the paint layer, methods were subsequently developed to include climate control, so that ions are mobilised and transferred to the rear support, in order to reduce salt concentration in the paint layer. This results in a more even salt distribution in deeper parts of the plaster or brick. Ideally, a new layer of plaster can be applied to the back, e.g. the supporting brick. The aim of this treatment is to ensure crystallisation within or upon this plaster, but it is difficult to achieve. Investigations nevertheless demonstrated a remarkable reduction of salt ions near the highly-vulnerable paint layer and a more even distribution in deeper parts, which may give more time to search for other solutions. Obviously this technique is restricted to relatively thin supports and cannot be applied in the case of cavity walls. 

In extremely corrosive services (such as sulfuric acid towers), where large-diameter towers are used with ceramic supports, brick arches or piers are often used as the support structure (386). 

In Fig. 1 (a) the complete workflow is represented by an activity diagram, the tool chain and the involved technological bricks are described in Fig. 1 (b). The same figure also reports the links between each activity of the workflow and its supporting brick. 

Figure 5. Schematic of ratcheting failure simulation results, (a) Loss of unsupported bricks indicates wear and surface roughness development, (b) Failed but supported bricks represent crack initiation and propagation.

A typical large three-phase ferroalloy furnace using prebaked carbon electrodes is shown in Eigure 4. The hearth and lower walls where molten materials come in contact with refractories are usually composed of carbon blocks backed by safety courses of brick. In the upper section, where the refractories are not exposed to the higher temperatures, superduty or regular firebrick may be used. The walls of the shell also may be water-cooled for extended life. Usually, the furnace shell is elevated and supported on beams or on concrete piers to allow ventilation of the bottom. When normal ventilation is insufficient, blowers are added to remove the heat more rapidly. The shell also may rest on a turntable so that it can be oscillated slightly more than 120° at a speed equivalent to 0.25—1 revolution per day in order to equalize refractory erosion or bottom buildup. 

Setter Tile and Kiln Furniture. These products are formed in a similar manner to bricks and are used to support ware during firing operation. The wide variety of available shapes and sizes include flat plates, posts, saggers, and car-top blocks. 

Roofs are a basic element of shelter from inclement weather. Natural or hewn caves, including those of snow or ice, ate early evidence of human endeavors for protection from the cold, wind, rain, and sun. Nomadic people, before the benefits of agriculture had been discovered and housing schemes developed, depended on the availabiUty of natural materials to constmct shelters. Portable shelters, eg, tents, probably appeared early in history. Later, more permanent stmctures were developed from stone and brick. SaUent features depended strongly on the avadabihty of natural materials. The Babylonians used mud to form bricks and tiles that could be bonded with mortars or natural bitumen. Ancient buildings in Egypt were characterized by massive walls of stone and closely spaced columns that carried stone lintels to support a flat roof, often made of stone slabs. 

Fig. 2. Downs cell A, the steel shell, contains the fused bath B is the fire-brick lining C, four cylindrical graphite anodes project upward from the base of the cell, each surrounded by D, a diaphragm of iron gau2e, and E, a steel cathode. The four cathode cylinders are joined to form a single unit supported on cathode arms projecting through the cell walls and connected to F, the cathode bus bar. The diaphragms are suspended from G, the collector assembly, which is supported from steel beams spanning the cell top. For descriptions of H—M, see text.

Furnace Design. Modem carbide furnaces have capacities ranging from 45,000 t/yr (20 MW) to 180,000 t/yr (70 MW). A cross-section of a 40 MW furnace, constmcted in 1981, having a 300 t/d capacity is shown in Figure 2. The shell consists of reinforced steel side walls and bottom. Shell diameter is about 9 m and the height to diameter ratio is shallow at 0.25 1.0. The walls have a refractory lining of 0.7 m and the bottom has a 1-m layer of brick topped by a 1.5-m layer of prebaked carbon blocks. The steel shell is supported on concrete piers and cooling air is blown across the shell bottom. A taphole to withdraw the Hquid carbide is located at the top of the carbon blocks. 

Catalytic Support Body Monolithic Honeycomb Unit. The terms substrate and brick are also used to describe the high geometric surface area material upon which the active coating material is placed. Monolithic honeycomb catalytic support material comes in both ceramic and metallic form. Both are used in automobile catalysts and each possesses unique properties. A common property is a high geometric surface area which is inert and does not react with the catalytic layer. 

The use of CO is complicated by the fact that two forms of adsorption—linear and bridged—have been shown by infrared (IR) spectroscopy to occur on most metal surfaces. For both forms, the molecule usually remains intact (i.e., no dissociation occurs). In the linear form the carbon end is attached to one metal atom, while in the bridged form it is attached to two metal atoms. Hence, if independent IR studies on an identical catalyst, identically reduced, show that all of the CO is either in the linear or the bricked form, then the measurement of CO isotherms can be used to determine metal dispersions. A metal for which CO cannot be used is nickel, due to the rapid formation of nickel carbonyl on clean nickel surfaces. Although CO has a relatively low boiling point, at vet) low metal concentrations (e.g., 0.1% Rh) the amount of CO adsorbed on the support can be as much as 25% of that on the metal a procedure has been developed to accurately correct for this. Also, CO dissociates on some metal surfaces (e.g., W and Mo), on which the method cannot be used. 

CP-1 was assembled in an approximately spherical shape with the purest graphite in the center. About 6 tons of luanium metal fuel was used, in addition to approximately 40.5 tons of uranium oxide fuel. The lowest point of the reactor rested on the floor and the periphery was supported on a wooden structure. The whole pile was surrounded by a tent of mbberized balloon fabric so that neutron absorbing air could be evacuated. About 75 layers of 10.48-cm (4.125-in.) graphite bricks would have been required to complete the 790-cm diameter sphere. However, criticality was achieved at layer 56 without the need to evacuate the air, and assembly was discontinued at layer 57. The core then had an ellipsoidal cross section, with a polar radius of 209 cm and an equatorial radius of309 cm [20]. CP-1 was operated at low power (0.5 W) for several days. Fortuitously, it was found that the nuclear chain reaction could be controlled with cadmium strips which were inserted into the reactor to absorb neutrons and hence reduce the value of k to considerably less than 1. The pile was then disassembled and rebuilt at what is now the site of Argonne National Laboratory, U.S.A, with a concrete biological shield. Designated CP-2, the pile eventually reached a power level of 100 kW [22]. 

The shell may be of metal (steel, alloy, or non-ferrous), plastic, wood or some combination which may require the addition of liners or inner layers of rubber, plastic or brick. The mechanical problems of attaching inner nozzles, supports and brick require considerable attention that is not an integral part of sizing the equipment. Figures 9-2A-C show a typical large steel brick-lined-membrane lined tower with corbeled brick support locations. In these towers, temperature and/or corrosive conditions usually dictate the internal lining, and the selection of the proper acid- (or alkali-) proof cements. 

Horizontal cylindrical tanks should be installed on brick or reinforced concrete cradles with a downward slope of 1 in 50 from the draw-off end towards the drain valve, as shown in Figure 18.1. Cradles should be constructed on foundations adequate for the load being supported and the type of soil. A reinforced concrete raft equal to the plan area of the tank, and of adequate thickness to bear the load, is normally suitable for all but the weakest soils. Cradles should not be placed under joints or seams of the tank plates and a layer of bituminized felt should be interposed between the cradle and tank. The height of the tank supports should provide at least 450 mm space between the drain valve and ground level to allow access for painting or draining the tank. 

Where overfilling or leakage from the tank would contribute to a fire hazard, cause damage to property or contaminate drains or sewers, a bund wall should be constructed around the tank. This should be of brick or concrete with an oil-tight lining, and sealed to the concrete base under the tank supports. The capacity of the bunded area should be at least 10 per cent greater than that of the storage tanks contained within it. 

Early twentieth century designs of FT boilers were often horizontal return tubular (HRT) designs. These boilers were classified as externally fired FT boilers and had an external, refractory brick furnace located under a near-horizontal shell and tube heat exchanger. The exchanger was supported on brick piers and tilted 1 to 2 inches down toward the blowdown pipe at the rear of the boiler to reduce the risk of burning the bottom shell plates because of sludge buildup. 

A rectangular iron ingot 15 cm by 15 cm by 30 cm is supported at the centre of a reheating furnace. The furnace has walls of silica-brick at 1400 K, and the initial temperature of the ingot is 290 K How long will il take to heat the ingot to 600 K ... 

Early workers viewed carriers or catalyst supports as inert substances that provided a means of spreading out an expensive material like platinum or else improved the mechanical strength of an inherently weak material. The primary factors in the early selection of catalyst supports were their physical properties and their cheapness hence pumice, ground brick, charcoal, coke, and similar substances were used. No attention was paid to the possible influence of the support on catalyst behavior differences in behavior were attributed to variations in the distribution of the catalyst itself. 

Depending on the technical requirements such as corrosion resistance, pressure and temperature stability, industrial scale azo pigment synthesis is carried out in appropriate equipment. Suitable materials include cast iron, stainless steel, steel lined with rubber, acid-proof brick, enamel, synthetic resins supported by glass fiber, and wood. 

The apparatus is assembled as shown in Fig. 5. Ammonia gas from a commercial cylinder (Note 1) enters the system at K. R is a mercury trap which would serve as a safety valve if the system should become blocked by solidification of the amide owing to an accidental drop in temperature. J is a U-tube containing just enough mercury to seal the bend, and it serves to estimate the rate of ammonia Sow. I is a Kjeldahl trap which prevents any mercury from being thrown into the fusion pot A, which (Note 2) is conveniently supported on a tripod set on bricks to raise it to a convenient height above the burner M. Through the cover of the fusion pot passes an outlet tube B, a thermometer well T, and the combined inlet tube CDE. The... 

The stack was constructed of an inner liner of hrick shrouded hy a concrete outer shell constructed of reinforced steel and concrete. The hrick and mortar liner had no reinforcing steel to support the assembly from side loading. The concrete shroud was primarily for protection against wind. A space of a few feet existed between the wall of the brick liner and the outer concrete shroud. The brick wall was about 3 to 4 feet thick at the bottom, and the wall thickness lessened with height. The concrete portion was of a similar design. 

The research of C.J. van Duijn and I.S. Pop was supported by the Dutch government through the national program BSIK knowledge and research capacity, in the ICT project BRICKS (http // www.bsik-bricks.nl), theme MSVl. 

---