RU2416078C2 - Universal device for analysis of granulometric composition of suspensions - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: device consists of rotating precipitating portion. A precipitator consists of a stabilising chamber, precipitating chamber and of a channel for centrate drainage. The precipitating chambers are divided with partitions with orifices for liquid flow. Precipitation is performed from a moving layer of liquid, while drying of sediment is done through additional orifices in the partitions between the chambers. The precipitating chamber rotates on a faceplate. A flat removable precipitating plate is set on the bottom of this chamber. Bigger particles settle near the partition between the stabilising and precipitating chambers, while finer particles settle further from the sad partition downstream on the flat removable precipitating plate. A rotating pipe line supplies suspension into the precipitator. The device is also equipped with a stationary portion of centrate reception made in form of a jacket for reception of centrate. A convex bottom of the jacket is inclined.

EFFECT: sedimentation of both large and fine particles of suspension during analysis, easy unloading of sediment with minimal losses and with maintaining order of settled particles.

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Description

FIELD OF THE INVENTION

The invention relates to precipitation centrifuges and is intended for research work.

State of the art

The prototype of the claimed device is a centrifuge (Russian patent document No. 2252824), including a casing with technological nozzles and a rotor installed in it on the shaft, consisting of a conical-cylindrical shell and a cover. The shell is located with the possibility of axial movement, and a disk with blades located inside the rotor on the shaft divides the inner space of the rotor into two parts. There is a friction unit. The rotor is located with the possibility of axial movement and stop when the shaft rotates, is equipped with a braking device and is connected to the shaft via a sliding bearing and a friction unit for connecting the shaft to the shell. The working surface of the friction unit is made of a material with a large value of the coefficient of sliding friction, such as fiberglass.

The advantage of this device is that it has increased performance.

The disadvantage of this device is that its design does not allow to collect sediment in a differentiated size state.

An analogue of the proposed device is a centrifuge with controlled selection of separation products (RF Patent No. 2323230). The invention relates to a device for separating liquid and other mixtures, while suspended particles can be in any state of aggregation.

The objective of the invention is to develop a continuous centrifuge design that allows you to control the apparatus performance, fractional composition of separation products, the number of selected separation products, and also allows you to quickly and conveniently disassemble the working part of the centrifuge for regular preventive maintenance, which is necessary in the case of using a centrifuge in the food industry.

The problem is solved by supplying a centrifuge with a continuously variable speed drive, by supplying a centrifuge with valves for the separation of separation products, adjustable in height of the selection of fractions and their throughput, by supplying the centrifuge with shirts for receiving separation products with connectors equipped with eccentric shutters.

The advantage of this device is the ability to obtain fractions with different particle size distribution.

The disadvantage of this device is that the possible sediment will be distributed over a large area of the shell, and this will complicate its collection for analysis. The range of sizes of suspended particles in each fraction is quite wide, this reduces the accuracy of the analysis.

Disclosure of invention

The objective of the invention is to develop a device for particle size analysis of suspensions of solid particles in a liquid. In this case, it is necessary to provide the possibility of determining the mass of each fraction of suspended particles. The number of fractions into which the suspension can be divided should be as large as possible. The range of particle sizes in each fraction should be as narrow as possible, and the particle size distribution of the suspension as wide as possible, that is, the apparatus should precipitate both large and tiny suspended particles. It is also necessary to determine the exact particle size and shape. The design of the apparatus should make it possible to easily unload the sediment with its minimum losses, without disrupting the order of the settled particles. Thus, the new apparatus should cover a wide range of research tasks and become universal.

In devices for studying the particle size distribution of suspensions, previously known, the main reason for the low efficiency is their narrow purpose and the inability of the design to convenient and accurate analysis of sediment.

A device is proposed consisting of a precipitator 1 (drawing, a), which rotates on the faceplate 2. The faceplate 2 is supported by a bearing 3 and rotated by a motor 4. And also the proposed device consists of: a suspension supply buffer 5 supported by a fixed support 6; fixed pipeline 7; adjusting valve 8; rotating pipeline 9 with funnel 10; and also from an annular shirt for receiving a centrate 11, which rests on a fixed support 12. A shirt 11 for receiving a centrate is provided with an inclined bottom of a convex shape and a fitting 13 for withdrawing the centrate from it. The inclined bottom of the shirt 11 allows you to almost completely remove the centrate from the shirt, which will positively affect the accuracy of the study. Precipitator 1, in turn, consists of a stilling chamber 14, a settling chamber 15, a discharge channel for the centrate 16, a partition 17 with a main opening 18 and an additional hole 19 between the stilling and settling chambers, a partition 20 with a main opening 21 and an additional opening 22 between the settling a chamber and a channel for removing the centrate. And also the precipitation chamber 15 is equipped with a removable flat vertical precipitation plate 23, which is installed on the bottom of this chamber.

The operation of the device is as follows. The torque from the motor 4 is transmitted to the faceplate 2 and the precipitator 1. The speed can be adjusted as necessary.

At the beginning of the work precipitator 1 is allowed to unwind to the operating speed. Next, fill the supply buffer 5 with suspension 24 (drawing, a) and open the valve 8, adjusting the flow rate of the suspension. Suspension through a stationary pipeline 7 is fed into a rotating pipeline 9 through its funnel 10. Through a rotating pipeline 9, a suspension is fed into a stilling chamber 14, where the turbulization of the suspension flow acquired in the rotating pipeline is reduced, and the energy of the impact of the jet on the bottom of the precipitator is dissipated in the stilling chamber. By centrifugal force, the suspension is pressed to the vertical bottom of the precipitator 1. Under the action of the suspension portions newly coming from the rotating pipeline, the latter flows into the precipitation chamber through the main hole 18 in the partition 17 and the additional hole 19 in the same partition. The cross section of the hole 19 is several times smaller than the cross section of the hole 18, this is necessary for the final stage of centrifugation and will be described below.

The cross section of the sedimentation chamber is larger than that of the other passage sections through which the suspension flows. Once in the sedimentation chamber, the flow moves laminarly upward, while larger particles, under the action of centrifugal force, settle out of the moving liquid layer closer to the partition 17, and smaller particles (under the same force) move further from the partition 17, thus being distributed , in size on the precipitation plate 23. The centrate 25, free of suspended particles, flows through the holes in the baffle 20 and is sent to the jacket 11 to divert the centrate by the outlet channel of the centrate 16. In the jacket 11, the centrate accumulates, flowing down from its walls and the inclined bottom, and is discharged through the fitting 13, after which it can be analyzed.

When centrifugation ends and the suspension ceases to flow from pipeline 9, the last portions of the liquid slowly leave the stilling chamber 14 through the additional hole 19. And also, the last portions of the liquid leave the sedimentation chamber 15 through the additional hole 22 in the baffle 20. Thus, the sediment plate 23 remains almost dry sediment of solid particles distributed by size.

By adjusting the diameter of the additional holes 19 and 22 (for example, by turning the nozzles in them), as well as by adjusting the suspension flow rate with a crane 8 and the precipitator speed 1, it is possible to configure the device to work with suspensions having a wide particle size distribution and different mass contents of the suspended phase. This allows us to talk about the wide versatility of the proposed device.

Next, the rotation and the precipitation plate 23 are stopped, removed together with the precipitate 26 (drawing, b). Depending on the experimental conditions, the precipitate can be dried directly on the precipitation plate or weighed wet immediately after receipt. For weighing, the precipitate is divided into the required number of "N" fractions (drawing, b) and removed from the precipitation plate with a blade or other similar tool. Next, the particles of each fraction are microscopic to determine their size and shape. The data obtained are sufficient to build the dependence of particle sizes and mass of the fraction containing these particles.

When implementing the invention, the following results can be obtained:

1. The proposed device will allow you to explore the particle size distribution of a wide range of suspensions of various origin and purpose.

2. The width of the particle size range can be chosen by the researcher and can be arbitrarily narrow, which means that the research results can be highly accurate.

3. The proposed device provides easy direct access to each fraction of settled particles. This will allow you to accurately and directly weigh and microscope them.

Brief description of the attached figures

The drawing shows a sketch of a longitudinal section of the proposed device for the study of particle size distribution of the suspension.

Claims (1)

A device for studying the particle size distribution of suspended solids in a liquid by centrifugal precipitation, consisting of a rotating precipitating part, characterized in that it includes a precipitating chamber, which consists of a stilling chamber, a precipitation chamber, a centrate discharge channel, the precipitating chambers being separated by partitions with openings for fluid movement, while the deposition occurs from a moving liquid layer, and the sediment is drained through additional holes in the partitions between the chambers, about the sowing chamber is made rotating on the faceplate and a flat interchangeable precipitation plate is installed on its bottom, with larger particles settling closer to the partition between the stilling and settling chambers, and smaller particles farther from the specified partition along the flow direction on the flat interchangeable precipitation plate , a rotating pipeline that provides suspension to the precipitator, and a fixed portion of the centrate reception, made in the form of a jacket for receiving the centrate, the convex bottom of which has a slope.

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