The number of conveying equipment in oil plants accounts for about 20% of all equipment, while the unplanned downtime caused by conveying equipment accounts for 60% to 80% of all unplanned downtime. Therefore, it is very important to improve the operating efficiency of conveying equipment.
This article compares the scraper conveyor and bucket elevator in oil plants.
1 Scraper conveyor
The scraper conveyor consists of a closed-section machine trough, a scraper chain, a track, a drive device, a tensioning device and a tail wheel.
The scraper conveyor can be used for horizontal, vertical and inclined feeding, and can be fed or discharged at multiple locations. Due to the good sealing of the machine trough, fly ash, toxic, flammable and explosive, and high-temperature materials can be transported. However, it should be noted that: ① When used to transport high-temperature and humid materials, such as softened materials, billets, puffed materials and finished meal at 55~65 ℃, high-temperature resistant materials should be selected, and the suction device should be selected. When conveying DC discharge with a temperature exceeding 100 ℃, the casing can be made of 304 stainless steel plate; ② When used to transport materials with strong permeability and flammability and explosion, such as solvent-containing wet meal, there should be stable joints-flanges and gaskets; ③ When used to transport materials with strong wear such as soybeans, wear-resistant lining plates or cast stones should be added to the machine trough, and wear-resistant treatment should be performed on the elbow arc; ④ For multiple discharges, double-layer scrapers should be used to prevent tail return or storage, such as multiple flaking mills, crushers, puffers, etc.
The operation of the buried scraper conveyor is closely related to the material performance. The horizontal scraper conveyor requires the material stacking density to be less than 1.8 t/m3, and it should be less than 1.0 t/m3 when conveying vertically. ; For conveying materials with high viscosity, such as flakes and expanded materials, a simple-shaped scraper should be selected to facilitate cleaning and unloading; for materials with good suspension and scattering properties, such as soybean meal, a scraper with a large enveloping coefficient and a complex shape should be selected; for conveying materials with large volume, such as soybeans, a wider machine trough can improve the strength and rigidity of the scraper, and a form with welded diagonal braces is selected to ensure the strength and rigidity of the scraper. The chain width of the scraper conveyor is 0.92~0.95 times the width of the chain; when conveying fragile materials and reducing noise, non-toxic and wear-resistant plastic scrapers are selected; when conveying fine powder materials with high bulk density, high proportion of large particles and high moisture content and the conveying distance is too long, the scraper is prone to "floating chain" or "stuck material". The scraper can be welded on the chain at a tilt of 70°~80° in the opposite direction of the chain operation, so that the movement resistance produces a vertical force that presses downward, so that the scraper chain runs close to the bottom of the trough to avoid "floating chain".
2 Bucket elevator
The bucket elevator consists of a base, an intermediate shell, a head, a drive device, a belt, a bucket, a speed switch, a field control button and a central control. The maximum lifting height of a domestic belt elevator is about 80 m, but it is required to be equipped with a high-strength belt. The maximum lifting height of a chain elevator is 50 m, and the return material volume is required to be controlled at about 3%.
The semicircular shell of the head needs to be a two-piece switchable type, and hinged inspection doors are provided on both sides near the discharge port to remove the bucket.
The bucket elevator is equipped with a check valve to prevent reverse operation when fully loaded or fully loaded. The bucket elevator should be able to start smoothly without any slipping when the bucket in the upward side cylinder is 100% full load and the base is filled with 1/3 of the material.
The upward and downward sides of the bucket elevator have their own independent cylinders. The cylinder is made of low-carbon steel plates, angle steels and other profiles (galvanized steel plates are recommended), with a thickness of not less than 4 mm. The height of a single cylinder is not more than 3 m to ensure vertical positioning in each direction under various load conditions (with a tolerance of ±3 mm).
The feeding method of the bucket elevator is divided into two types: forward and reverse. The high-level feed should form a 60° angle with the horizontal plane, which is used for materials with poor scattering, such as green billets, cooked billets, wet materials, and powdery materials. The low-level feed forms a 45° angle with the horizontal plane, which is used to convey dry and well-scattered materials. It is more appropriate that the lower part of the feed port is 100~150 mm higher than the center level of the tail shaft to avoid blockage of the feed port. The lowest front shell plate of the feed surface is made of a detachable type or plug-in plate, which can be quickly opened to clean out the accumulated materials at the bottom of the machine base when blocked.
Our Vic Machinery can choose the appropriate conveyor according to the characteristics of your materials and production process.
