The Manufacturing Process Bricks Summary Of Process Engineering Essay

The really first measure to bring forth bricks is to oppress and crunch the natural stuffs in a centrifuge and a jaw crusher. Following, intermix the ingredients required for each peculiar batch is selected and filtered before directing on to one of the three brick determining procedure ( bulge, casting, pressing ) . Bulge determining procedure is the most adaptable and most common procedure. These bricks are dried to take extra wet which might do checking during the resulting fire procedure. Afterwards, they are fired in oven and so cooled. Finally, they are stacked utilizing machines which will wrap it with steel sets and padded with fictile corner defenders.

Manufacturing process measure by measure:

Measure 1. Crunching, sizing, and intermixing natural stuffs

A centrifuge is a machine that removes outsize stuffs. Each of the ingredients is transferred to a centrifuge in the really first measure. Then, a jaw crusher with horizontal steel home base ( fig 6.1.1a ) is to compact the articles and to do them to even smaller pieces.

Fig 6.1.1a

The following procedure is to divide them to different sizes of stuffs utilizing a scalping screen ( fig 6.1.1b ) . Correct size stuff will be sent to storage silos which the over-sized stuff goes to a cock factory ( fig 6.1.1c ) , which will lb it with fast traveling steel cocks. This cock factory uses another screen to command the maximal size of atom which are allow to go forth the factory, while the remainder goes to many vibrating screens that separate out stuff of improper size before it is sent on to the following stage of production.

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Fig 6.1.1b Fig 6.1.1c

Measure 2. Bulge

As mentioned in drumhead, bulge is the most adaptable and most common procedure. It is fed into one terminal of a pug factory ( fig 6.1.1d ) , which uses knives on a revolving shaft to cut through and fold stuff together in a shallow chamber. The blend is so fed into an extruder-usually consist of two chambers-at the far terminal of the factory. Extruder ‘s ( fig 6.1.1e ) first chamber removes air from the land clay with the aid of vacuity ; hence prevent snap and other faulty. The 2nd chamber of extruder compact the stuffs so the plumber’s snake can squeeze out it through the dice. After it is compressed, a fictile stuff is forced out of the chamber though a die-like opening. The cross-section of the extruded column is formed into the form of the dice. Desired lengths are with revolving knives or stiff wires.

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Fig 6.1.1d Fig 6.1.1e

The 2nd method is modeling. Soft wet clay is placed in wooden box to determine in a cast. The inside of the box is normally coated with sand, which helps to supply the texture and facilitates we want, After that, the formed brick will so be removed from cast.

The last method is pressing. This method requires a stuff with low H2O content. The stuff is placed in a dice so compacted with a steel speculator set at a coveted force per unit area.

Measure 3. Beveling the brick

To bring forth bricks that are meant for the application of pavement, beveling machines ( fig 6.1.1f ) were developed. These machines have rollers which indent the bricks as it is being extruded. Sometimes they are besides fitted with wire cutters to make the chamfering and cutting at the same time. Hence, such machines can bring forth every bit much as 20,000 units/hour

Fig 6.1.1f

Measure 4. Coating

The pick of the sand surfacing depends on the softness and hardness of the extruded stuff. For soft stuff, a continuously vibrating feeder ( fig 6.1.1g ) is used to surface, whereby for textured stuff the coating may be brushed or rolled on. For harder stuff, a force per unit area roller or compressed air is used. Last, for highly difficult stuff, sand blasting is necessary.

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Fig 6.1.1g

Measure 5.Drying

This measure is indispensable before the following step-firing. The bricks must be dried to take extra wet. If the wet did non travel off, the H2O will vaporize off excessively rapidly during sauteing, which will consequences in checking. There are two types of dryer-tunnel drier and automatic chamber drier.

Tunnel drier ( fig 6.1.1h ) is utilizing autos to travel the bricks through humidity-controlled zones that prevent checking. They consist of a long chamber through whereby the ware is easy pushed. To rush up the procedure, external beginnings of fan-circulated hot air are forced into the drier.

Fig 6.1.1h

For automatic chamber drier ( fig 6.1.1i ) , the extruded bricks are automatically placed in rows on two parallel bars. Next, the bricks are fed onto particular racks with finger-like device that hold several braces of bars in multiple bed. Last the racks are so transferred into driers by rail-mounted transportation autos or by lift trucks. hypertext transfer protocol: //

Fig 6.1.1i

Measure 6. Open firing and chilling

This is the 2nd last measure that the bricks will travel through. After the bricks are dried, they are loaded onto autos ( the same autos that used to travel the bricks through the drying procedure at measure 5 ) automatically and moved into big furnaces called tunnel kilns ( fig 6.1.1j ) normally range from 1000 – 1200 & A ; deg ; C. These autos are pushed through the kiln ‘s continuously maintained temperature zone at a specific rate, depending on the stuff. Tunnel kilns have different design from high-load. Narrow-width kilns to shorter and lower-set has wider kilns which can fire more bricks. This type of design has besides result to supplying high speed, long-flame and lower temperature fire burners, which really helps to better temperature uniformity and lowered fuel ingestion.

After firing, the bricks are left for chilling.

Fig 6.1.1j

Measure 7. Puting and packaging

After the bricks are fired and cooled, they are unloaded from the kiln auto by dehacking procedure, which is an automatic procedure to the point where about all manual brick handling is eliminated. Automated puting machines ( fig 6.1.1k ) have been developed, which can put bricks at rate of over 18,000 /hour and can revolve the bricks at 180 grade. Normally set in rows, the broad about 11 bricks, a stack is wrapped utilizing steel sets and fitted with plastic strips which act as corner defender here. The packaged bricks are so shipped to the topographic point that order ; illustration occupation site-usually usage roar short pantss to drop.

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Fig 6.1.1k


Summary of procedure

To bring forth concrete block, it merely requires four basic procedure: commixture, casting, bring arounding and cubing. Some fabrication workss produce merely concrete blocks while others produce many assortment of precast concrete merchandises such as blocks, level paver rocks and cosmetic landscape gardening piece ( e.g. lawn inching ) . Some fabrication workss have the capableness to bring forth 2000 or more blocks/hour.

Manufacturing process measure by measure:

Measure 1: Mix

The sand and crushed rock are stored outside in hemorrhoids and are transferred into storage bins in the works utilizing conveyer. To protect from dampening, the Portland cement is stored outside in big perpendicular silos.

To get down bring forthing, the needed sum of sand, crushed rock and cement are transferred either gravitation or mechanical agencies to a weigh batcher which will mensurate the proper sum of each stuff.

These dry stuffs are so flux into stationary sociable. This is the topographic point where they are blended together for several proceedingss. There are two normally used sociables. One is call planetal or pan sociable ( Fig 6.2.1a ) , while the other is call horizontal membranophone sociable ( Fig 6.2.1b ) . Plan mixer is expressions like a shallow pan with a palpebra. Its commixture blades are attached to a perpendicular rotating shaft inside the sociable. On the other manus, horizontal membranophone sociable looks like a java can that turned on its side. Its blending blades attached to a horizontal rotating shaft inside sociable.

Now that these dry stuffs had blended together, a little sum of H2O is added to the sociable. Before making so, the at bay H2O content in the sand and crushed rock is measured utilizing supersonic detectors, and the sum of H2O needed to add to the mix is automatically adjusted to counterbalance the demands. The H2O may foremost necessitate to go through through warmer or hair-raiser to modulate its temperature, depending on where the fabrication works located. If the works is located in a topographic point where the temperature is utmost, it is necessary.

Following, admixture chemical and colouring pigments are added to the sociable. The concrete is so assorted for following six to eight proceedingss.

Fig 6.2.1a Fig 6.2.1b

Measure 2: casting

Now that the concrete is exhaustively assorted, it is transferred into an inclined pail conveyer ( Fig 6.2.1c ) and so to an elevated hopper. After being transferred, the commixture rhythm will get down once more for the following burden. From the hopper, the concrete is conveyed to another hopper on top of the block machine ( Fig 6.2.1d ) at a mensural flowing rate. As the blocks emerge from the block machine, their tallness is checked utilizing optical maser beam detectors. In the block machine, the concreted is being forced downward into casts. In one clip, every bit many as 15 blocks can be molded. When the casts had range to maximum, the concrete is compacted by the weight of the upper mold caput coming down on the cast pits. This compression may be reinforced by air or hydraulic force per unit area cylinders moving on the mold caput.

Next, the compacted blocks are pushed down and out of the casts onto a level steel palette. Follow by that, the palette and blocks are pushed out of the machine and onto a concatenation conveyer. In some operation, the blocks have to go through through a revolving coppice to take loose stuffs at the top of the blocks.

Fig 6.2.1c Fig 6.2.1d

Measure 3. Bring arounding

The palettes of blocks are following transferred to an automated stacker or stevedore, which will reassign them in a hardening rack. One rack can keep several hundred blocks. When the rack is full, it will be rolled onto a set of tracks and moved into bring arounding kilns.

The kiln, an enclosed room, is able to keep several racks of blocks at a clip. Basically, there are two type of bring arounding kilns. One is low- force per unit area steam kilns ( fig 6.2.1e ) while another is hard-hitting steam kiln ( fig 6.2.1f ) . The most normally used is low-pressure steam kiln, whereby the blocks are put in the kiln for one to three hours at room temperature to let them to somewhat indurate. Steam is so released in to increase the temperature, but commanding the rate non more than 16 & A ; deg ; C per hr.

Standard weight blocks are cured at 66-74 & A ; deg ; C and lightweight blocks at 77-85 & A ; deg ; C. when the hardening temperature reached to the coveted temperature, the steam is shut off, and the blocks will be soak in the hot moist air for following 12 -18 hours. After soaking, these blocks will be dried by wash uping the moist air and farther addition the temperature in the kiln. To drumhead, the whole hardening procedure will takes about 24 hours.

On the other manus, in high- force per unit area steam kiln ( besides known as sterilizer ) the temperature is raised to 149-191 & A ; deg ; C and the force per unit area at 5.5-12.8 saloon. The blocks are so allowed to soak for five to 10 hours. The force per unit area is so really rapidly vented, which really allows the blocks to rapidly let go of their at bay wet. This procedure requires more energy and more expensive kiln. However the advantage is that it can bring forth blocks in a shorter clip.

In these processs, the temperature and the force per unit area are all controlled and recorded automatically so as to guarantee that the blocks are cured decently, in order to accomplish their needed strength.

Fig 6.2.1e Fig 6.2.1f

Measure 4 Cubing

The last measure is cubing ( fig 6.2.1g ) . After being cured, the blocks are rolled out of the kiln, and the palettes of blocks were removed from the stack and placed on a concatenation conveyer. The blocks are so separated by the steel palettes, and the empty palettes are send back into the block machine, where it will be refilled with a new set of blocks

The blocks so pass through a cuber which arrange each block neatly, so stacks them in a regular hexahedron three blocks across by six blocks deep ( 3 x 6 ) or three or four blocks high ( 3 x 3/ 3 ten 4 ) . Last, these regular hexahedrons are carried outside with a forklift and so placed in storage. The concrete blocks are now ready to utilize.

Fig 6.2.1g