GB2177367A - Bucket elevator - Google Patents

Abstract

A bucket elevator comprises a shoe (1) and a head (4) interconnected by means of pipes (7) and (8) containing a vertical tractive element (11) with buckets (12). The pipes (7) and (8) are provided with windows (9) and (10) interconnected through a sleeve (15) for transportation of a bulk load from the pipe (7) of the ascending branch of the vertical tractive element (11) to the pipe (8) of the descending branch whereas the pipes (7) and (8) are enlarging in the areas of their connection to the sleeve (15), the minimum distance of the lower edge of the window (10) of the pipe (8) from to the upper edge of a loading window (2) of the shoe (1) being defined by the following relationship: Hmin = Q/S.n, where Q - volume flow rate of the load; S - effective surface of the bucket (12) cross-section; n - number of buckets (12) crossing the level of the load in the shoe per time unit.

Description

SPECIFICATION Bucket elevator Technical Field The present invention relates to industrial conveyance and hoisting facilities and, more particularly, it relates to bucket elevators.

Prior Art The basic problem associated with improvement of bucket elevators resides presently in increasing their effficiency and reliability of their operation while reducing the specific consumption of materials and energy.

There is known in the art a bucket elevator comprising a drive drum and a tension drum, a vertically closed traction means with buckets accommodated in pipes communicated with a head and a boot, and a device for controlling the elevator charging fashioned as a gate in the boot (cf., U.S.

Patent No. 2,494,165, class 19S55, of 1950).

However, in view of the variable nature of the properties of bulk cargo (moisture content, impurity content etc.) and of the conditions of its entry into the charging port of the boot (for example, velocity), no constant flow rate of bulk cargo through the gap between the gate and bottom edge of the charging port can be maintained even if the position of the gate remains the same.

Therefore, such a design fails to protect the elevator from "heaping up" which may occur as a result of spilling of excess bulk cargo from the buckets on leaving the boot.

Further known in the art is a bucket elevator (cf., German Patent No. 683,520, class 81 E29, of 1939) comprising a drive drum and a tension drum respectively accommodated in a head and in a boot with a charging port, a vertically closed traction means with buckets whose ascending and descending sides are arranged in pipes, a discharging branch pipe of the head being provided with ports communicated via chutes with ports of the ascending side pipe while said chutes are inclined towards said latter pipe at the angle of repose of bulk cargo.

In such an elevator, the inclined chute does not ensure "heaping-up"-free operation.

Essence of the Invention This invention is aimed at solving the problem of developing a highly reliable bucket elevator by way of altering the structure of portions of pipes of ascending and descending sides of a traction means, which adjoin a boot.

The problem set is solved owing to the fact that, in a bucket elevator comprising a boot with a charging port inside which there is mounted a tension drum, a head with a charging port inside which there is mounted a drive drum, pipes with ports serving to interconnect the boot and the head, a traction means with buckets arranged within the pipes and rounding the drive and tension drums, and a device for controlling the charging of the elevator, said device fashioned as a branch pipe communicating said pipes via the ports, according to the present invention, the branch pipe is positioned between the pipes with a possibility of conveying bulk cargo from the pipe of ascending side of the traction means to the pipe of descending side while the pipes are made flared in the zones where the branch pipe is connected therewith, the minimum distance from the bottom edge of the port of the pipe of descending side of the traction means to the top edge of the charging port of the boot being defined by the relationship 0 Hmin = S-n wherein Q -- volume flow rate of the cargo; S - effective cross-sectional area of the bucket; n - number of the buckets crossing the level of cargo in the boot per unit time.

It is expedient that the branch pipe be inclined towards the pipe of descending side of the traction means at the angle of repose of bulk cargo.

Such a design of the bucket elevator provides for reliable operation thereof at any amount of cargo being delivered. It is expedient that the branch pipe be provided with a V-shaped divider which may be fashioned as vertically mounted partitions attached to the bottom wall of the branch pipe and forming an acute angle whose vertex is directed towards the pipe of ascending side of the traction means. Such a branch pipe design enables one to direct excess bulk cargo to the pipe of descending side bypassing the traction means, directly to the zone of movement of empty buckets.

It is recommended that the buckets be attached to the traction means with a pitch of V t 0 wherein - -- volumetric capacity of the bucket; V-rate of the traction means.

Such an arrangement of the buckets provides for fully capturing excess bulk cargo delivered to the pipe of descending side.

It is expedient that a portion of the pipe of ascending side be provided on the inside with transverse partitions secured successively one above the other on a portion from the boot to the port location on the ascending pipe at the place of joining of the branch pipe and, in so doing, it is expedient that said portion of the pipe be made flared to the size of the pipe in the zone where the branch pipe is connected therewith while the transverse partitions be secured with a slope to the outer wall at the angle of repose of the cargo being conveyed.

Such partitions help reduce the resistance to the movement of the traction means with buckets in the portion from the boot to the port on the pipe of ascending side.

Summary of the Drawings The present invention will be more apparent upon considering the following description of exemplary embodiment thereof with due references to the accompanying drawings in which: Figure 1 shows diagrammatically the bucket elevator according to the present invention; Figure 2 shows fragmentary view A of Fig. 1, in section, according to the present invention; Figure 3 is a section taken on the line Ill-Ill of Fig.

2, according to the present invention; Figure 4 shows an embodiment of ascending pipe with protective partitions, according to the present invention; Figure 5 is a section taken on the line V-V of Fig.

4, according to the present invention; and Figure 6 shows fragmentary view B of Fig. 4, according to the present invention.

Preferred Embodiment of the Invention Referring now to Fig. 1 of the accompanying drawings, the bucket elevator of the present invention comprises a boot 1 with charging ports 2 on end surfaces thereof in which a tension drum 3 is mounted, and a head 4 with a discharging port 5 in which a drive drum 6 is located. The head 4 and the boot 1 are interconnected by means of pipes 7 and 8 with ports 9, 10, respectively (Fig. 2).

Mounted inside the pipes 7 and 8 is a traction means 11 provided with buckets 12. The means 11 bends round the drive drum 6 and the tension drum 3, with the side of the traction means 11 located in the pipe 7 being ascending and that located in the pipe 8 -- descending.

The pipes 7 and 8 in the zone of the ports 9 and 10 are made with flared out portions 13 and 14 interconnected by means of a branch pipe 15.

The port 9 and the flared out portion 13 of the pipe 7 of ascending side serve to lead excess bulk cargo out of the pipe 7 and direct it into the branch pipe 15 whereupon said cargo is delivered to the zone of movement of empty buckets 12 via the port 10 and the flared out portion 14 of the pipe 8 of descending side. It is necessary that the port 10 of the pipe 8 of descending side be positioned at such a height with respect to the charging port 2 of the boot 1 (Fig. 1) that the empty buckets 12 (Fig. 2) of the descending side should take up the entire excess bulk cargo delivered via the branch pipe 15. While so doing, the minimum distance from the bottom edge of the port 10 of the pipe 8 of descending side of the verticaltraction means 11 to the top edge of the charging port 2 of the boot 1 is defined by the relationship.

Q Hmin = S-n wherein Q-volumeflow rate of the cargo; S-effective cross-sectional area of the bucket 12; n - number of the buckets crossing the level of cargo in the boot 1 per unit time.

It is expedient that the branch pipe 15 be inclined towards the pipe 8 of descending side of the traction means 11 at the angle of repose of bulk cargo.

This makes for gravity conveyance of excess bulk cargo from the pipe of ascending side of the traction means 11 to the pipe 8 of descending side.

The branch pipe 15 can be positioned at any other angle with respect to the pipes 7 and 8 provided it is -equipped with an additional arrangement ensuring the conveyance through said branch pipe of excess bulk cargo from the pipe 7 of ascending side to the pipe 8 of descending side.

There is possible an embodiment in which the branch pipe 15 is provided with a V-shaped divider 16 (Fig. 3) which may be fashioned as vertical partitions 17 and 18 attached to the bottom wall of the branch pipe 15 and forming an acute angle a whose vertex is directed towards the pipe 7 of ascending side.

Such a design provides for directing excess bulk cargo to the pipe 8 of descending side bypassing the traction means 11, directly to the zone of movement of the empty buckets 12 of said side.

For fully capturing excess bulk cargo delivered to the pipe 8 of descending side, the buckets 12 are attached to the traction means 11 with the pitch of V tci-, Q wherein i-volumetric capacity of the bucket; V-rate of the traction means 11.

Such an arrangement of the buckets provides for fully capturing excess bulk cargo.

In orderto reduce the resistance to the movement of the traction means 11 with the buckets 12 in the portion from the boot 1 to the port 9 of the pipe 7 of ascending side, the pipe 7 is provided on the inside with transverse partitions 19 (Figs. 4, 5) secured successively one above the other with a slope to an outer wall 20 of the pipe 7 at the angle of repose of the cargo being conveyed, said portion of the pipe 7 being made flared to the size of the flared out portion 13 of the pipe 7 of ascending side. The partitions 19 form with each other inclined channels 21 and, with the wall 20, a vertical channel 22. Said partitions 19 are provided on the side facing the buckets 12 with elastic cover plates 23 (Fig. 6) to protect them against accidental damage by the moving buckets 12 (Fig. 4).

Consider now the operation of the bucket elevator according to the present invention.

Bulk cargo such as grain is delivered to the boot 1 (Fig. 1) via the charging port 2, taken up by the buckets 12 (Fig. 2) of the traction means 11, conveyed to the head 4 (Fig. 1) and, upon the rounding of the drum 6 by the traction means 11, discharged via the discharging port 5. When excess amount of grain is accumulated in the boot 1 and when its column in the pipe 7 of ascending side rows, on reaching the flared out portion 13 (Fig. 2) grain flow over via the branch pipe 15 to the flared out portion 14 of the pipe 8 of descending side from which it is once again delivered into the buckets 12.

The divider 16 (Fig. 3) provides for directing excess amount of grain to the zone of flared out portion 14 (Fig. 2) that is not overlapped by the traction means 11 on the side of the branch pipe 15. The choice of the height of location of the port 10 of the flared out portion 14 of the pipe 8 and of the pitch with which the buckets 12 are mounted is done such as to ensure uninterrupted functioning of the apparatus.

For excess grain to be taken up by the buckets 12 of the descending side, the branch pipe 15 must adjoin the pipe 8 of said side at a point that is above the level of grain in the boot 1 (Fig. 1) on the descending side by a value at which the moving empty buckets 12 (Fig. 2) are capable of taking up all of excess grain delivered prior to encountering the main flow of grain delivered via the charging port 2 (Fig. 1) into the boot 1.

When the partitions 19 (Fig. 4) are mounted inside the pipe 7 of ascending side, excess bulk cargo flows via the inclined channels 21 to the channel 22 and then to the boot 1 (Fig. 5). As a result, horizontal pressure of the mass of excess cargo acts upon the partitions 19 (Fig. 4) to considerably reduce the resistance to the movement of the traction means 11 with the buckets 12 and, thereby, the amount of electric power consumed during the operation of the bucket elevator.

The present invention provides for a stable elevator operation upon maximum filling of the buckets and for the protection of the elevator against "heaping up" without resorting to mechanical and electromechanical means of control and protection, with any amount of bulk cargo delivered to the elevator. This makes for a higher reliability of operation of bucket elevators by elmininating the need to stop the latter due to "heaping up" and, thereby, ruling out the stoppage of conveyance and production lines associated with such elevators.

Industrial Applicability The present invention can be used in the manufacture of new and updating of the existing bucket elevators employed for vertical conveyance of bulk cargoes in the elevator, flour-and-cereals, mixed fodder and food industry, in agriculture, in the production of building materials and in other branches of industry where bucket elevators are employed.

Claims (5)

1. A bucket elevator comprising a boot with a charging port and a tension drum mounted thereinside, a head with a discharging port and a drive drum mounted thereinside, pipes with ports serving to interconnect the boot and the head, a traction means with buckets arranged inside the pipes and rounding the drive and tension drums, and a device for controlling the charging of the elevator, said device fashioned as a branch pipe communicating the pipes via the ports, characterized in that the branch pipe (15) is positioned between the pipes (7, 8) with a possibility of conveying bulk cargo from the pipe (7) of ascending side of the traction means (11) to the pipe (8) of descending side while the pipes (7, 8) are made flared in the zones where the branch pipe (15) is connected therewith, the minimum distance from the bottom edge of the port (10) of the pipe (8) of descending side of the traction means (11) to the top edge of the charging port (2) of the boot 1 being defined by the relationship Q Hmin = S'n wherein Q-volume flow rate of the cargo; S - effective cross-sectional area of the bucket (12); n - number of the buckets (12) crossing the level of cargo in the boot (1 ) per unit time.

2. A bucket elevator as claimed in claim 1, characterized in that the branch pipe (15) is inclined towards the pipe (8) of descending side of the traction means (11) at the angle of repose of cargo.

3. A bucket elevator as claimed in claims 1, 2, characterized in that the branch pipe (15) is provided with a V-shaped divider (16) made up of vertically mounted partitions (17, 18) attached to the bottom wall of the branch pipe (15) and forming an acute angle a whose vertex is directed towards the pipe (7) of ascending side of the traction means (11).

4. A bucket elevator as claimed in claim 1, characterized in that the buckets (12) are attached to the traction means (11) with a pitch of V ti -, Q wherein - -- volumetric capacity of the bucket (12); V-rate of the traction means (11).

5. A bucket elevator as claimed in claim 1, characterized in that inside a portion of the pipe (7) of ascending side there are provided transverse partitions (19) secured successively one above the other on a portion from the boot (1 ) to the port (9) located on the pipe (7) at the place of joining of the branch pipe (15), said portion of the pipe (7) being made flared to the size of the pipe (7) in the zone where the branch pipe (15) is connected therewith while the transverse partitions (19) are attached with a slope to the outer wall of the pipe (7) at the angle of repose of the cargo being conveyed.