bucket elevator lip plate

bucket elevators

bucket elevators

Bucket elevators are used for the elevation of dry or pulped ore. They consist of an endless chain or beltcarrying the buckets vertically or at a steep angle. On reaching the top pulley they should turn at sufficient speed to fling their contents out with a measure of centrifugal force. The feed is directed into a gathering boot or to buckets rising from a boot. Wet ore can be drained through perforations in the buckets. A rod can be so suspended as to rap the discharging bucket and so help to shake out packing sludge.

Belt bucket elevators are by far the most common appliance for elevating ore, whether wet or dry. For wet work, they have the advantage over chain-bucket elevators of requiring no difficult and expensive lubrication and of having fewer wearing and friction-producing surfaces. The capacity of a given belt, however, is limited by its adhesion to the head pulley; this can be augmented by a wrapping of less slippery material around the pulley. As compared with inclined conveyors, they occupy much less floor space, and can also elevate thin pulps. It is important to provide means for emptying the boot of an elevator when repairs are needed; so placed that the discharged material can be sluiced or easily transferred by other means to an adjoining elevator.

A Bucket Elevator Conveyor compared to classic belt conveyors which can handle the bulk of the dry ore moved through the modern plant, have a system including a tripper. The belt conveyor obviously includes the belt, the carrying and return idlers (B and E), the take-up (F), the tripper and shuttle belts if used, the drive (C), the belt cleaner (near D).

The standard rubber belt has a cotton foundation which must be strong enough to withstand the driving pull and the loading strains. The weight of duck in ounces, refers to a single thickness or ply 36 x 42. Plies are bonded together with rubber, and the pull needed to separate two plies in a strip one inch thick is termed the friction. It is between 12 lb. and 24 lb. and chosen for required duty and flexibility. The plies must not separate under the worst conditions (i.e. when rounding the end pulleys). This carcass (plies) is protected above and below by rubber, of the specified tensile strength (800-4000 PSI). Covers vary in thickness from 1/16 to . For severe service, a breaker strip of open mesh fabric may bind cover the carcass and confine any tear arising in use. Cord belts have additional longitudinal cords embedded in rubber.

A bucket elevator consists of a number of buckets (d) fastened to an endless chain or belt (a) running respectively on two sprockets or pulleys (b, c) at different elevations. Material is fed at (e) directly into the buckets or is scooped up from the BOOT (f) and carried up and discharged into a receiving hopper (g) as the buckets pass over the upper (HEAD) wheel. The line joining the centers of the pulleys or sprockets may be inclined at any angle between 65 or 70 and the vertical. Bucket elevators are called continuous if the buckets are spaced practically touching and centrifugal discharge if the buckets are spaced say one or more bucket-depths apart. The height of lift in concentrating mills is seldom over 75 ft. but there is no definite limit in the ordinary range of requirements.

The drive is usually by a spur gear on the head shaft and pinion on a jackshaft belt-driven from a motor or line shaft. Direct belt drive from a line shaft to the head shaft is sometimes used; also direct connection of a motor to the pinion shaft. Gear drive is better than belt drive because it permits higher drive-belt speed and belt drive is better than direct connection because the belt will slip in case of a sudden jam and possibly save breakage of the bucket line.

The Head shaft should be extra heavy and as short as possible. The greatest stress is due to the weight of the loaded bucket line and to sudden shocks arising from obstruction to the free motion of the line; a shaft strong enough to support this loading is more than large enough to transmit the necessary power. A light shaft that bends under load causes uneven and excessive wear on bearings.

Size of the head shaft. Let w = total load in lb. of shaft, pulley, bucket line and ore; l = length in inches of the shaft between bearings; d = diameter of shaft in inches; z = section modulus = d/32; s = permissible working stress in lb. per sq. in. = say 5000 lb. Then wl/4 = sz = 5000 d/32 and d = wl/1963.5.

Bearings may be of the standard pattern but preferably ball-and-socket, grease lubricated. Special collars with an interlocking rim to cover the end of the bearing are sometimes used to exclude grit; closed ends aid exclusion. Shafting is frequently turned down on the ends to permit the use of smaller-sized bearings.

A rubber belt is a usual medium for carrying buckets in American concentrating-mill practice; balata belts have been widely used in South Africa. Rubber elevator belts are usually made with 32-oz. duck; for heavy work, 36- or 42-oz.; with a 1/32- to 1/8-in rubber cover on the pulley side for protection against pulley slip and some cover on the bucket side also, to provide for the wear of entering feed; for wet materials, the cover on the pulley side is usually twice as thick as on the bucket side and ranges up to 1/8-in. The edges usually have an extra-heavy covering. The belt should be two to four in. wider than the bucket to prevent the buckets from catching on the housing or any other projection. Elevator belts are subject to heavy loads; surface wear is severe both on account of loading conditions and slip and creep at the head pulley; the perforations for bolts allow access of grit and water, and this in conjunction with acute bending around small boot pulleys, and frequent bending due to short length disintegrates the internal bond (friction). (Creep is a change in belt length, due to difference in tension on the two sides of the head pulley, so that the belt shrinks in passing from the upside to the downside and this causes relative movement between the surface of the pulley and the belt).

Belt replacement is the most important item of upkeep in elevator operation so that precautions to extend belt life pay for themselves in short periods. On elevators with buckets spaced some distance apart and run at low speeds, triangular strips of wood are sometimes fastened to the belt between buckets to prevent material from running along the belt and getting caught behind the buckets; this practice is reported to have greatly increased the life belts.

Chain bucket elevators, in spite of their multiplicity of wearing and breaking elements, can be used satisfactorily far dry work but must then be lubricated with heavy grease to minimize the effect of grit; their capacity is limited only by the size of buckets that, can be supported. Certain types have a pronounced advantage in being able to receive or discharge at a number of points in their travel, thus combining the functions of elevator and conveyor.

The advantage of a Chain Bucket Elevator over a conveyor belt is that it can lift material vertically and can handle large quantities of material. The special design of the buckets ensures high stability and reduced risk of spillage.

A Bucket Chain Elevator is designed to lift material from point A to point B by means of buckets. The buckets are pulled by two chains. The Chain Bucket Elevator is typically used to lift the reject material and return it to the main flow in a sampling solution.

The Chain Bucket Elevator consists of an inlet hopper, a vibration feeder, buckets, a gear-motor drive, inspection hatches, and an outlet chute. There is an inlet hopper at the bottom with a VF that provides a consistent flow of the material into the buckets. The buckets are mounted on the chain that continuously pulls the buckets around by a geared motor. At the top of the unit, there is an outlet chute where the buckets are emptied. There is a drawer in the lower section allowing for easy cleaning. The chain is manually adjustable.

The Bucket Belt Elevator (BBE) is designed to lift material from point A to point B by means of buckets. The buckets are attached to a belt that pulls them around. The Belt Bucket Elevatoris typically used to lift the reject material and return it to the main flow.

There is an inlet hopper at the bottom with a VF that provide a consistent flow of the material into the buckets. The buckets are mounted on the belt that continuously pulls the buckets around by a geared motor. At the top of the unit there is an outlet chute where the buckets are emptied. There is a drawer in the lower section allowing for easy cleaning. The belt is manually adjustable.

All sampling equipment and solutions aim for compliance with the principles laid down in the Theory of Sampling (TOS) and gives our customers reliable knowledge of the material properties such as moisture content, particle size distribution, mineral proportions, and content grade essential for commercial, operational, and technical characterization.

The Bucket Lifter (BL) is designed to lift material from A to B by means of one or more buckets. Compared to the Chain Bucket Elevator or the Belt Bucket Elevator, the Bucket Lifter is specifically designed for lifting smaller quantities of material.

The Bucket Lifter consists of a gear motor, bucket(s), a chain/belt and a steel construction. A loading station in the bottom ensure that the bucket(s) is being dosed correctly. The bucket(s) are lifted to the top where it is emptied when it is tilted around. After a preset time, tilted, the bucket reverses and returns to the bottom, ready for the next filling. If the Bucket Lifter has more than one bucket, each bucket is being emptied one after the other before the all the buckets are return to the bottom section.

All sampling equipment and solutions aim for compliance with the principles laid down in the Theory of Sampling (TOS) and gives our customers reliable knowledge of the material properties such as moisture content, particle size distribution, mineral proportions, and content grade essential for commercial, operational, and technical characterization.

Those familiar with mill-practice understand the work required of an average bucket elevator, but I wish to call special attention to the wear on the buckets. I have been studying in what manner the life and service of the bucket might be improved, and I feel that an adjustable lip, attachable to each bucket without the aid of rivets, will be of material advantage.

For illustration (Fig 1 & 2), consider the feed-elevator of a typical mill in the Coeur dAlene district. The ore is carried by water in a launder from the feed-rolls and dumped in the boot of the elevator, directly in front of the ascending bucket. Middlings from the return-rolls are similarly handled. Under this condition the bucket not only carries the ore, but also picks it up, and this latter requirement determines the life and service of the bucket. It might be said that it would be better practice to convey the feed to the elevator and dump it directly into the bucket, but at one mill at which this plan was tried the results were disappointing and the rubber belt was badly worn.

The wear of the bucket is confined to the lip and the corners which have to pick up the material. When the lip on a corner of a 7- by 12-in. malleable cast-iron bucket is worn down about 3 in., the bucket is of no further value as a carrier and has to be replaced. The worn bucket, containing about three-quarters by weight of the metal of the original bucket, has a scrap value of about 10 per cent, of that of a new bucket. To the cost of the bucket, however, should be added the time-cost of replacing the old bucket by a new one. This time-cost is considerable when the loss per hour, to cease operating the mill.

It is out of the question to put lips on a bucket unless the latter was originally fitted with this device. For if it is attempted to fit lips upon buckets not originally provided with them, it will be necessary to drill holes for rivets and then spend considerable time fitting the lips to the irregular contours of the worn buckets. The improvement suggested is an adjustable attachment which can easily be fastened to, or removed from, the base of a bucket without the use of rivets. This attachment, to be made of a high-grade steel drop-forging or casting, will combine toughness, hardness, and tensile strength. The base of the bucket may be a cheap casting,

possibly ordinary cast-iron. This combination of lip and base will not increase the cost of the improved bucket much, if any, above that of the ordinary bucket now in use, but will increase the life of the bucket, doing the same amount of work, about 400 per cent., with a corresponding decrease in time lost in changing buckets.

This improved bucket is illustrated in Fig. 1, which shows a projection of the bucket with the attachment in place. Two bolts, one on each side of the elevator-belt, pass through the base and attachment and hold both fast to the belt. These end-bolts are 0.25 in. longer than the others. Fig. 2 shows the bucket with part of the lip removed, illustrating the manner in which it is fitted to the base and the opening at A which receives the lug A. There is another opening at B, which is not shown.

I am indebted to Stanley A. Easton, (General Manager of the Bunker Hill & Sullivan mine, for the following data, which bear out my statement, and show that others have been trying to improve the service of elevator-buckets. He says that they use there 7.75- by 17-in. malleable cast-iron buckets, which give approximately 80 days continuous service on middlings-elevators,

4b fabricated steel digger elevator buckets and cups

4b fabricated steel digger elevator buckets and cups

At 4B we have helped to upgrade hundreds of bucket elevators over the years for many different industries. Our application engineering expertise includes: grain storage, animal feed, flour milling, brewing, biomass, cement, coal, frac sand, as well as other processing industries.

Using your key technical data, 4B engineers will provide preliminary design and component details to enable your bucket elevator to operate at its optimum capacity and discharge potential. If your existing elevator cannot be upgraded to meet your current needs, 4B engineers can provide a basic design for a new one.

plate steel elevator buckets (din) - vav aandrijvingen bv

plate steel elevator buckets (din) - vav aandrijvingen bv

The plate steel elevator buckets come either in a deep or a shallow version. Completely in accordance with DIN 15231, 15232, 15233, and 15234. The correct bucket is selected depending on the product, fine or crude material.

These buckets are available in a pressed or welded version and feature recessed holes. VAVoffers you a selection of various different materials, such as: S235JR, S355J2G3, Hardox 400 / 500, Ceusabro 4800 / Manganstahl 1.3401, Edelstahl 1.4301 / 1.4401 / 1.4571.

bucket elevator design considerations

bucket elevator design considerations

Whether replacing an existing bucket elevator, or building a new plant altogether, there are a few crucial decisions the purchaser should be prepared to make during the buying process. Here are some of the key design decisions that will require consideration when engaging a bucket elevator supplier.

Bucket elevators are primarily manufactured in two different discharge configurations: centrifugal and continuous. One of the first questions a bucket elevator manufacturer will ask is which elevator style the project calls for.

Continuous-style bucket elevators operate at slower speeds and lower capacities, offering gentle handling for materials that are fragile or susceptible to aeration; they are the preferred choice for applications such as potash and other fertilizers where degradation or attrition is a concern.

Continuous bucket elevators are also the best choice when handling materials that are either abrasive or inconsistent in particle size; the scooping and throwing action of the centrifugal-style elevator does not lend well to these types of materials.

Material is fed from a chute into buckets as they pass through the boot section. Buckets are designed and arranged in a way that allows the back of each bucket to serve as a discharge surface onto which the previous buckets material passes, making its way to the discharge chute via gravity.

Centrifugal-style elevators are better suited to faster, smoother handling applications where degradation or aeration of material are not a concern. This type of handling is typical of free-flowing or powdered materials and is often used for sand and ore.

The centrifugal elevator style self loads by scooping material from a hopper as it passes through the boot section. On passing over the head pulley, the buckets discharge material by throwing it into the discharge chute via centrifugal force. This elevator type operates at higher speeds and accommodates greater capacities, and as such, is the preferred choice at shipping terminals and other high-volume settings.

Centrifugal Bucket Elevator The image above illustrates the operation of a centrifugal-style bucket elevator. Note how loading is primarily a result of the buckets scooping material and discharge occurs as a result of throwing via centrifugal force.

The bucket elevator manufacturer will also want to know whether a belt- or chain-type elevator is preferred. Both belt and chain bucket elevators offer a reliable handling solution, with the decision between the two types coming down to practicality and cost.

Belt elevators offer a cost-effective solution for applications such as sand handling (a centrifugal belt-style elevator with nylon buckets offers a highly effective and economic option in such settings). They are also the preferred choice when noise is a concern, as they are much quieter than their chain counterparts.

This elevator style does, however, have some limitations. While less costly, they are not as durable as chains, making them less of a fit for especially demanding applications, such as those found at mine sites. They are also not recommended when the material to be handled is hot, or presents a risk of combustion. Further, since large particles could become wedged between where the bucket is mounted onto the belt, causing damage, the belt-style elevator is best suited for smaller particle sizes ( roughly and smaller) that avoid this risk.

While smaller belt elevators can handle capacities comparable to that of a chain elevator, this is only true up to a point; in addition to a lower tensile strength, their capacity is limited by practicality; beyond a certain capacity, the size of the casing and components required would be impractical.

Chain elevators are also the best option for handling higher-temperature (greater than 400F) or potentially combustible materials, as well as materials of a larger particle size that could otherwise become lodged between a bucket and belt.

A well-chosen bucket style often means the difference between seamless production and constant downtime for bucket repair or replacement. Elevator buckets are available in a wide range of styles and materials depending on whether the chosen elevator is of the continuous or centrifugal design.

Since centrifugal elevators will require the buckets to scoop up material, buckets in this category are equipped with a reinforced lip on the leading edge in order to discourage any distortion during digging.

AC Buckets are chosen for especially heavy-duty applications, or when the material being conveyed is hot or highly abrasive. This bucket style also accommodates a much higher capacity than the AA bucket style.

Close-centered, or CC buckets are an increasingly popular bucket style for centrifugal elevators. The buckets unique shape, along with a design that allows buckets to be spaced closer together, offers additional capacity over what AC buckets can handle.

Inspection doors are important for troubleshooting or routinely examining elevator performance and the overall condition of the equipment. Further, some operations may require access doors that allow for easy access to the units internals for changing or cleaning buckets, shoveling or washing out the boot section, or other routine maintenance procedures.

Bucket elevators typically come with access doors at the boot section and inspection doors at the head section, but additional access or inspection doors may be helpful at the intermediate sections as well, depending on the applications. Depending on where the bucket elevator is located in the plant, and the surrounding infrastructure, ladders and safety cages, as well as platforms may also be necessary.

The purchase of a new bucket elevator requires several design decisions on the part of the purchaser. For those new to bucket elevators, FEECO can walk you through the process and provide guidance on critical decisions based on your handling requirements and goals.

FEECO has been providing reliable bucket elevators to a range of industries since 1951. Our diverse material experience, combined with our flexible design process and high quality standards, ensures you get the best handling system for the job. For more information on our bucket elevators, contact us today!

elevator buckets muller beltex

elevator buckets muller beltex

We also supply welded (according DIN standards) or plastic buckets for minerals and particularly challenging conditions, centrifugal or gravity discharging. Our elevator bucket program also includes the well-known European models (Columbus, Starco and Super Starco) in pressed steel, stainless steel, HDP, polyurethane or nylon.

For over 25 years Muller Beltex has been the distributor in Europe of Maxi-Lift plastic elevator buckets. These are very economical buckets for high capacities and abrasive bulk products. All types are available in HDPE, wear-resistant and non-adherent polyurethane or Zytel heat-resistant nylon and are very abrasion-resistant.

Our stockholding strategy and top-quality product range allows us to always offer the right solution for your elevator. Largely the result of our customers needs we have continuously been optimising our product range.

From experience we know which elevator components and moving parts are subjected to the most wear. What lies at the heart of optimal and safe bulk processing is the elevator belt: to us, the elevator belt is the key. A good quality elevator belt is crucial and can be offered with Polysur.

The connection is the weakers link in an elevator belt, which is why belt fasteners deserve special attention. We supply various belt fasteners for connecting belts with specially woven polyester/polyamide plies (EP) or steel fabric reinforcements.

Muller Beltex likes to share their knowledge as a consultant for your specific issue. Engineering,advice and supervision services to get your bulk handling and processing equipment running optimally. By involving us at an early stage, we can offer you the right solution based on our broad experience and know-how.

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