Zasidko Andrey

Electrotechnical faculty

Department of Mining Transport and Logistics

Speciality "Electromechanical Equipment of Power–Consuming Industries"

Research and working out of a feeder of a new technological level of the raised maintainability for an unloading of a mineral from bunkers of mine transport lines

Scientific supervisor: Sklyarov Nikolai

Summary of research and developments

Introduction

Prominent feature of modern mines is concentration of works and increase of loadings on clearing faces. Modern coal–mining complexes provide high efficiency of clearing faces, and transportation of mountain mass on excavation from lavas to a skip trunk is carried out by modern highly reliable conveyors.

On a way of passage of coal from lava to a skip trunk coal can many times pass through various heat–sink capacities: the bunker, slopes, funnels and other. Unloading of mountain mass from capacity is carried out by feeders. During the unloading of mountain mass there are often demurrage of feeders because of disrepair in start–up of equipment, damages of power and control cables, faults of the driving electric motor, etc.

The immediate task of scientists, designers and operatives is to provide proof rate of unloading of mountain mass from heat–sink capacities by increase of maintainability of a feeder and a non–admission of the compelled demurrage mining sites and a hoist engine because of a feeder which are connected with electric equipment faults.

The feeder is a device for uniform giving not sticky, loose mountain mass from bunkers, loading trays, shops and other loading devices to transporting and processing cars.

Proof rate of unloading and non–admission of idle times are probable to reach by performing of a complex of technical actions:

— Use of the reserve electric motor, which kinematically connected with high–speed shaft of a driving feeder reducer;

— Start of the reserve electric motor from the reserve magnetic actuator which is connected to a network;

— Maintenance of automatic inclusion of the reserve engine at refusal of the worker;

— Presence of light indication which would signal about inclusion of each electric motor.

Thus, working out of the constructive scheme of a feeder of the raised maintainability is the actual problem which decision is very necessary for highly productive mines.

The purpose and research problems

Research and working out of a feeder of a new technological level is the purpose of modern scientific work. For object in view achievement it is necessary to solve following primary goals:

— to make the analysis of existing designs of feeders with definition of their advantages and lacks at operation in the conditions of mine, and to define their technological level;

— to construct a morphological card of feeders, to choose and prove a variant of a design of a feeder from total number which are most applied in the conditions of mine;

— to develop the constructive scheme of a feeder and constructive means of increase of his maintainability;

— to execute necessary strengthening calculations of additional elements of the projected feeder;

— to execute calculations of maintainability of a feeder;

— to execute calculation of economic benefit of use of a feeder of the raised maintainability.

Classification of feeders

Feeders are divided into 2 groups:

1.  Devices similar to some types of conveyors, but, unlike them, possess in the small length and the raised capacity of the engine of a drive. Distinguish the following kinds of feeders concerning this group:

— tape feeders;

— lamellar feeders;

— spiral (screw) feeders;

— shaking feeders;

— vibrating feeders.

2.  Devices not having prototypes among conveyors. This group of feeders concern:

— drum–type feeders;

— disk feeders;

— chain feeders;

— pneumatic screw feeders.

Tape feeders are intended for uniform giving of dry materials with bulk weight to 2,8 t/m³ in cars and transporting devices. Are applied at the enterprises mountain, iron and steel industry; on lines on release of dry building mixes, etc. In tape feeders giving of dry materials is carried out by means of a tape which is set in motion from the electric motor through chain transfer or a reducer. The moving tape delivering a material to transporting or processing cars, settles down directly under the bunker from which the material is strewed. The quantity of a material submitted a feeder is regulated special damper, and also speed of movement of a tape.

Lamellar feeders are intended for transportation and uniform giving of loose materials of mountain–concentrating manufacture from one capacity (the bunker, a funnel) in other capacities, in working cars or on warehouses. The feeder cloth, as a rule, represents steel шарнирную a design which is a component of the conveyor for giving of a loose material in open–cast mines and at concentrating factories.

Spiral (screw) feeders represent a pipe or a trench in which the working body — the screw is placed. The rotating core placed in a horizontal or inclined trench, moves loose or мелкокусковой cargo along a trench. Productivity adjustment is made by increase in speed of rotation of the screw. Screw feeders are intended, basically, for continuous and uniform giving of a loose material. A scope is acquisition of plants and technological lines with the set dosage of a material.

Shaking feeders are cars of the continuous transportation which working body is the tray making back and forth motions, intended for uniform giving not sticky, loose materials from bunkers, funnels and other capacities in technological cars or transporting devices.

Vibrating feeders are intended for uniform giving not sticky loose materials for installation under bunkers on horizontal sites as loading devices or metering devices. Material delivery on working body which is a round pipe occurs at the expense of her oscillative motions.

Drum–type feeders are applied as to giving of well loose, granular and small–lumpy cargoes, and for крупнокусковых cargoes. For giving of well loose, granular and small–lumpy cargoes feeders have a smooth internal surface of a drum, and for giving large–lumpy cargoes — a ridge surface.

Disk (plate–shaped) feeders are applied to loose cargoes. Disk feeders are supplied by the loading device from which cargo gets on a disk rotating round a vertical axis and is dumped from him by motionlessly fixed scraper. Speed of rotation of a disk gets out such that сбрасывание cargo didn't occur under the influence of centrifugal force.

Chain feeders applied for large–lumpy cargoes, have the so–called chain curtain blocking a final aperture of the bunker. At rotation of driving chain drum press to a tray a cargo layer, regulating speed of his sliding.

Pneumatic screw feeders (canyons–pumps) apply to giving loose dust–forming materials and from usual screw feeders. Differ that on an exit the material is grasped and transported by a current of air.

A feeder choice on base of the multicriterion analysis

The problem of scientists, designers and operatives – to provide proof rate of unloading of mountain weight from heat–sink capacities by increase of maintainability of a feeder and a non–admission of the compelled idle times of a mining site and a hoist engine because of a feeder, connected with electric equipment refusals. It can be reached performance of a complex of technical actions:

— Use of the reserve electric motor, kinematically connected with high–speed shaft of a driving feeder reducer;

— Realization of a food of the reserve electric motor from the reserve magnetic actuator connected from a network;

— Maintenance of automatic inclusion of the reserve engine at refusal of the worker;

— Presence of light indexation which would signal about inclusion of each electric motor.

Thus, working out of the constructive scheme of a feeder of the raised technological level is the actual problem which decision is rather necessary for high–efficiency mines.

The choice of a rational design of a feeder of the raised technological level can be made by comparison of feeders with model of a fictitious reference feeder which has the highest properties (parameters) reached in various types of feeders.

Estimation of a technological level of feeders taking into account their functional maintenance can be carried out by a technique.

According to this technique it is possible to calculate technological levels of feeders of various designs and to choose the best.

The complex indicator of a technological level of a feeder is defined in such order.

1. "Specific indicators" (x_ij), which turn out the relation of private indicators (b_ij) to the basic technical parameter of a feeder (λ_i), for which one of appointment indicators is recommended to accept are defined.

2. 2. For definition of base values of "specific indicators", value of "specific indicators" (x_ij) bring in the table–matrix:

where n — quantity of the private indicators accepted for an estimation of a technological level of a feeder;

m — number of feeders in the considered set.

For value of "base specific indicators" (x_iб) accept the maximum values of specific indicators which choose from each column of the table–matrix.

where {x_iб} — dynamic model of the fictitious reference car which has the highest properties, already reached in different cars.

3. Are defined technical equal j–th car behind private indicators it is defined under the formula:

For a base design of a feeder

4. Define destiny of participation (m_ij) a private indicator in their total sum at n the selected indicators and participation factor (φ_ij) each private indicator:

5. Total value of private indicators of a technological level of j feeders (Ψ_j) taking into account participation factors it is defined under the formula

6. 6. A complex indicator of a technological level of j feeders (Π_j) define under the formula:

      According to [3] for the basic technical parameter (λ_i) a feeder it is accepted his weight, kg.

      For a technological level estimation there were accepted such parameters of a feeder:

В1 — The maximum productivity, Q, м³/ч;

В2 — Maximum largeness a piece of a transported material, а мах, мм;

В3 — Width (diameter) cargo–carrying body, м;

В4 — Capacity of an occasion, N, kW.

      Definitions of a technological level of feeders were defined in such order.

      The data collected under catalogs about technical parameters of feeders it is brought in tab. 1.

      Table 1 — Specifications on feeders

      Table 2. — Definition of specific indicators X_ij=B_ij/λ_j

      Table 3. — technological level Definition on own indicators τ_ij=X_ij/B_ij  τ_iб=1

      Table 4. — Definition of a share of participation of indicators in general quantity m_ij=τ_ij/Στ_ij  m_iб=1/n

      Table 5. — intermediate : (1 — m_ij )

      Table 6. — Definition of a share of participation of indicators in general quantity φ_iб=1

      Table 7. — Total values of each indicator j–th feeder (Ψ_j) taking into account participation factors (φ_ij)

      From the received results of calculations of technological levels of feeders of various models probably to draw such conclusion:

—"Shaking feeder ПК—10П " (fig. 1) which has П_j = 0,7733;

—This feeder probably to accept as base for working out of a feeder of the raised technological level.

The feeder has designation ПК–10П, where:

П — a feeder;

К — shaking;

10 — width of a mobile tray, dm;

П — manufacturing of Petrovskij factory of coal mechanical engineering.

The conclusion

      From the received results of multicriterion analysis a technological level the greatest at a shaking feeder, him we will accept for the further improvement of his design. Shaking a feeder represents the car of the continuous transportation which working body is the tray making back and forth motions. The feeder works with the greatest return only in that case when the quantity of a submitted material strictly corresponds to his processing ability. Reduction or increase in this quantity negatively affects productivity of cars and can lead to car breakage. From long–term operating experience of shaking feeders, the electric motor overload is a failure principal cause.

The list of sources

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2. Grigoriev V. N, Clerks of Century А, Pukhov J.S.Transportnye of the car for underground razrabotok. th.: bowels, 1984. — 384 with.

3. A technique of an estimation of quality of mountain cars / Malt of Century, Sychev of h.p., Radkevich J.M., Laktionov B. I.— Scientific bases of creation of the high–efficiency in a complex–mechanized mines with vychislitelno–logic management. Under the editorship of Malt of Century of I., 1974, with. 162 – 166.

4. Budishevsky Century О, Muhopad N.D., Sulima A.A., Kislun V. A. Shahtny transport. — Donetsk: type. "Novy svit", 1997. — 349.

5. Transport at the mountain enterprises. B.A.Kuznetsov, A.A.Rengevich, V.G.Shorsh, etc. — М: Nadra, 1976. — 552.

6. Guzenkov P.G.Detal_ of cars.М "Vishcha shkola", 1975.

. Reshetov D.N.detail of cars. The textbook for high schools. M, "Mechanical engineering", 1975.