GB2166482A - Mobile plant for the modification of clay and manufacture of modified-clay building products for rural development - Google Patents

Abstract

This invention is concerned with the design of a complete production unit consisting of a range of skid-mounted machinery and other equipment which can be conveniently transported to various sites in rural districts where both clay and operating space are readily available for on-site production of modified- clay building materials featuring qualifications which comply with contemporary rural building requirements. This range of machinery constitutes the basic requirements for the operation of a unique mobile plant which can be brought to distant locations and temporarily installed to produce clay building materials for foundations, walls, floors and roofs. This eliminates the need to transport conventional building materials from central districts or far-away factories, thus avoiding heavy transport charges and inevitable delay. Through work conducted in this field where simple hand-operated equipment was used to modify clay and make the early specimens of these clay products, I was able to determine the right proportion of water and binder added to the prepared dry clay, and to set down specifications for the machinery required to perform the modification and manufacturing process with accuracy which ensures the production of modified-clay building materials to the required standards, and at a moderate cost.

Description

SPECIFICATION Mobile plant for the modification of clay and manufacture of modified-clay building products for rural development SPECIFICA TIONS The remarkable advance modern technology has achieved in all fields of activity included an important development in the design of machinery and equipment used in brick factories in various parts of the world, to increase the output and improve the quality of the products of this industry which had hitherto relied on primitive manual methods of brick-making using simple hand moulds, over the centuries.

The target of this technical development was to provide larger quantities of sun-dried clay bricks and prepare them for burning or baking in simple or sophisticated kilns, to satisfy the ever increasing demand everywhere for this vital material.

It is obvious that this baking process calls for the construction at fabulous costs of permanent structures such as kilns and ancillary buildings which cannot be dismantled and moved after erection. This increases the cost of production and curtails the advantage of this industry in faroff rural areas.

This reveals the importance of setting up a modified-clay building materials industry. Materials that can be made by this mobile production unit from modified clay which dries and hardens spontaneously after manufacture, without the need for burning.

This mobile plant consists of a set of machinery and equipment conforming to specified requirements. Their design was prepared in the light of trials I have conducted during the past few years to confirm the feasibility of performing mechanically this four-stage production process efficiently as outlined below:1. Materials Preparation Stage.

2. Clay Modification and Kneading Stage.

3. Pressing and Forming Stage.

4. Demoulding and Sun-Drying Stage.

The machines are fitted with adjustable metering devices which can be programmed for synchronized operation. They are interconnected through a central console which monitors the performance of each unit to avoid error during operation, ensuring considerable saving in manpower. The plant includes the following units as shown in the attached diagram: RAW MATERIALS PREPARATION STAGE Al Power Operated Box Feeder: A rectangular shaped machine which accepts raw material from the quarry and delivers it at a controlled rate to the crushing and grinding stage.

A2 Adjustable Grinding Rolls: A cylindrical grinding machine fitted with revolving rollers designed to squeeze the clay lumps and reduce the raw material to the particle size required for the modification process.

A3 Screen Arrangement: After grinding the clay passes through a screening stage to remove grass, tree roots and coarse material before being conveyed to the storage silo.

A4 Processed Dry Clay Silo: A cylindrical steel silo for the storage of prepared dry clay. It is fitted with a metering device for controlled operation, and a power operated propeller to facilitate a steady discharge of clay to the surge hopper.

A5 Surge Hopper with adjustable metering device and discharge control, so it can only receive a predetermined volume of earth per mix and deliver it all in one batch into the mixer via a twoway shutter arrangement linked with a vibrator unit. This makes it possible to discharge into one mixer all the time, or alternately discharge into two mixers for dual flow-line operation. In this case, the cylindrical solution tank B3 and the surge hopper A5 should be programmed for synchronous operation to ensure simultaneous flow of materials into either of the two mixers.

CLAY MODIFICATION AND KNEADING STAGE B1 Emulsion Binder Storage Tank: A cylindrical steel tank for bituminous emulsions, fitted with agitator, electric pump and a special control valve to deliver a specified quantity of emulsion to the solution tank via a programmed measuring device which functions in accordance with the specifications selected for each type of clay product.

B2 Elevated water storage tank built over a skid-mounted steel structure, and connected with a small cylindrical tank at the bottom. This is fitted with variable adjustment to control the quantity of water added to the clay.

B3 Cylindrical Solution Tank with stainless steel lining fitted with electric stirrer fixed on a steel shaft to agitate the bituminous emulsions prior to pumping them to the pugging stage.

B4 Horizontal Clay Mixer/Pugmill designed to receive a specified quantity of prepared dry clay from the surge hopper for each batch, and perform the process of modifying and kneading the clay upon discharge of the binder and water from the solution tank B3 via sprinklers fixed on the top to avoid the formation of clay lumps during mixing, and ensure a homogeneous clay mix.

B5 Wet Clay Storage Hopper: The modified and kneaded wet clay is discharged into a storage hopper to clear the mixer for the next batch.

S2 The wet clay hopper B5 is fitted with a two-way shutter arrangement linked with the central control panel by a programming device to direct the flow of modified clay to the pressing stage in the flow-line constantly, or to divert it to a conveyor belt which empties in special carts or trucks designed to carry the modified clay to the building site where it is used as building mortar.

CLA Y PRESSING AND FORMING STAGE C1 This stage features vertical presses which exert low pressure on the modified clay mix flowing in steadily from the wet clay storage hopper.

C2 The clay presses are equipped with automatic mould washing and sanding machines, and can be fitted to produce efficiently clay bricks in various shapes and sizes, or clay floor tiles in the required dimensions.

DEMOULDING AND SUN-DRYING STAGE D1 Demoulding Turntable: At the end of the forming stage, the filled moulds are directed to a rotary demoulding machine which extracts the wet clay bricks or tiles and places them on steel or timber pallets prior to moving them to the open air drying area.

D2 Hand Carts or Forklift Trucks are used to carry the finished clay products to the drying area.

This requirement is determined by the level of production.

To ensure self-sufficiency and complete independence at all stages of production, this mobile unit should be equipped with a mobile generating set to provide the electric power required to operate the machinery and equipment as well as the screw-feed and open -belt conveyors which handle the dry earth and modified wet clay through the four production stages to maintain a steady flow of these materials to the machines included in the plant.

(English translation of the Arabic text of the Specifications filed with the application for Patent Registration No. 163/84 on 23/10/1984)

Claims (5)

CLAIMS The design of this plant was prepared in the light of trials conducted in the past few years, which enabled me to obtain the grant of five patents concerned with modified-clay building materials. The results yielded by these trials, and my previous experience in the clay-brick industry made it possible to determine the basic requirements in material and equipment for the production of modified-clay building products, and to design a mobile plant capable of performing this operation mechanically with considerable efficiency. This mobile plant features the following characteristics:

1. It consists of a complete range of machinery designed to perform the function of clay modification and manufacture automatically in four stages, which ensures satisfactory production quality and quantity wise.

2. Ail the machinery included in this plant are skid-mounted to facilitate transport from one site to another for temporary installation in far-off rural areas. This skid mounting also assists in hoisting and loading the machines on special low-loaders for easy transportation of the plant to other sites.

3. All of these machines are inter-connected by a central control panel which monitors the performance of each unit with considerable precision to ensure efficient operation of the plant with minimum man-power requirement.

4. Most of the machines particularly those in the critical stages are equipped with adjustable controls and metering devices which can be programmed in accordance with the specifications selected. This helps to avoid error in maintaining a constant ratio for clay mixing and modifying, ultimately ensuring the required quality and quantity of production

5. A mobile plant according to Claim 1 and Claim 4, with considerable manufacturing flexibility whereby a variety of modified-clay building products for walls, floors, roofs and foundations can be economically produced as described hereinabove, the said flexibility being derived from the coordinated action of the integrated group of machinery operating in the four production stages, and the function of the adjustable controls and metering devices fitted on equipment located in the critical phases of the manufacturing process, thus ensuring a constant level of bitumen binder content prescribed for each type of the said products.

DIAGRAMA TIC LAYOUT OF MOBILE PLANT Showing arrangement of machinery and equipment included, and sequence of flow-line operation in the clay manufacturing process.

LEGEND: R Incoming raw materials-Earth F Outgoing finished clay products-Bricks, Floor tiles or Roof tiles.

STAGE A: Materials Preparation Stage Al Box Feeder-lncoming raw materials A2 Adjustable Grinding Rolls A3 Screen Arrangement A4 Dry Earth Storage Silo A5 Surge hopper S1 Two-Way Shutter arrangement for dual flow line operation STAGE B: Clay Modification Stage B1 Additive Tank-Bituminous Emulsions B2 Elevated Water Tank B3 Solution Tank B4 Clay/Mixer Pugmill B5 Wet Clay Storage Hopper S2 Two-Way Shutter Arrangement for Alternative Discharge of modified clay Building Mortar STAGE C: Pressing and Forming Stage C1 Clay Press to handle Wet Clay fed into Pressure Chamber C2 Automatic Mould Washing and Sanding attachment STAGE D: Demoulding and Drying Stage D1 Demoulding Turntable to extract clay products from moulds and place them on pallets.

D2 Hand carts or Forklift truck as required to remove pallets to drying area.

Notes: Open-Belt or Screw-Feed conveyors are provided to handle flow of materials between stages, ensuring efficient operation of plant and maximum production.

Floor and roof tiles are transferred to glazing facility after drying.

5. Adjustments provided to control the binder content in the clay mix in the correct proportion during the modification process, and the adaptability of the various units to produce clay building materials in different shapes and dimensions, ensure great flexibility to operate more than one flow-line simultaneously, which means considerable saving in production costs.

(English translation of the Arabic text of the Claims filed with the application for Patent Registration No. 163/84 on 23/10/1984.

CLAIMS Amendments to the claims have been filed, and have the following effect: Claims 1 to 5 above have been deleted.

New claims have been filed as follows:

1. A mobile plant comprising a range of purpose-built machinery and equipment which can be conveniently transported to various sites in remote rural districts, and temporarily installed for on-site operation to produce different types of bitumen-modified clay building products for rural development. The individual machines included in the aforesaid plant are substantially designed for synchronous operation whereby each unit in the said temporary installation performs a specialised function in the four-stage production process which commences with the delivery of the incoming raw earth and terminates with the removal of the finished clay products to the sundrying area whither they cure and harden spontaneously without baking, as set out in the accompanying schematic diagram.

2. A temporarily installed plant according to Claim 1, wherein raw dry earth having been initially prepared by grinding and screening in the materials preparation stage, is subsequently fed into a mixing stage hereinafter referred to as modification stage, wherein a specified proportion of a given type of bitumen emulsion is uniformly incorporated in the clay mix, the said emulsion having been diluted with the right amount of water to obtain the prescribed plasticity. The said mix is then thoroughly kneaded by a special clay mixer/pugmill to achieve complete dispersion of said bitumen emulsion, and ensure a homogeneous wet clay mass of suitable consistency for making modified-clay building products as described hereinabove.

3. A mobile plant according to Claim 2, featuring a sequential order of operation substantially dependent on the function of regulating the flow of prepared dry clay and bituminous modifying materials into the modification stage as prescribed, and the simultaneous discharge of the right amount of water to maintain a constant clay/Bitumen binder/water ratio as specified for each type of product, and ensure uniformity in appearance and performance characteristics of the said product.

4. A production system according to Claim 3, wherein the modified clay mix of prescribed plasticity is directed via a two-way shutter arrangement S2 to the pressing and forming stage C to make modified-clay bricks, floor or roof tiles, or alternatively diverted to a discharge point M where the said modified clay is loaded onto trucks and carried to the building site to be used as clay mortar.