SU924544A1 - Device for continuous extraction of suspension liquid phase - Google Patents

Description

The invention relates to analytical instrumentation and, being a device for sampling the liquid phase of the suspension directly in the process apparatus, can be used in systems for automatic analytical control of liquid media in the chemical, hydraulically metallurgical and other industries.

A device for sampling the liquid phase of a suspension is known, which comprises a vertical pipe-clarifying flow dispenser and a valve system. Through the open lower end of the clarifier tube, immersed in the suspension, the latter enters the dispenser and after 2-3 minutes (after deposition of solid particles) enters the analyzer 11-.

The drawback of the device is a periodic mode of control of the composition of the suspension, as well as low reliability of the valve system, additional communications for flushing with condensate when working with aluminate and other pulps prone to the formation of gypsum precipitates.

The closest device is a continuous sampling device.

suspension containing the measuring chamber in the form of a pipeline installed in the process apparatus 2. The pipeline is made of a dielectric material with a tapered and bent down the upper end. At the lower end of the pipe, the solid phase is released from the suspension. The resulting difference in the specific gravity of the suspension in the apparatus and the liquid phase in the pipe gives rise to the last upstream of the liquid phase 21.

Use of this device

15 for the system of automatic control of the composition of the liquid phase and the concentration of solid particles in suspensions of alumina production is difficult for the following reasons; the open lower end of the pipeline does not allow the setting of the mode of deposition of solid particles with different specific gravity (the device is used only for heavy suspensions);

25 aluminate suspensions of alumina production possess the property of K1 installation and release of gypsum sediment-on the walls, therefore conditions are created in the upper narrowed and curved part of the pipeline

for making sludge and pipeline throat growth. In addition, in the presence of air bubbles in the suspension (evaporation for suspensions with elevated temperature, from operating pumps), the latter accumulate in the upper part, blocking the narrow part of the pipeline in a bend (air block). The presence of air bubbles reduces the accuracy of the measurement of electrical conductivity by conductometric m & a method, and the use of an acoustic method for the speed of ultrasound propagation is generally impossible. Installing and removing sensors in a pipe for routine inspections and maintenance requires the entire device to be removed from their process unit.

The purpose of the invention is to expand the field of use and increase the availability of the device and the representativeness of the sample being measured.

The goal is achieved by the fact that in the device for continuous extraction of the liquid phase of the suspension, containing a measuring chamber in the form of a pipeline installed in the process apparatus, the measuring chamber is equipped with a cone which is installed coaxially with the lower part of the pipeline, pointing inwards and at a distance from the lower end of the pipeline, the base of the cone is made with a diameter greater than the diameter of the pipeline, and the upper end of the pipeline is located above the surface of the suspension.

The presence of a cone in the lower part of the pipeline and fixing it with a gap leads to the fact that the directional flow of the suspension through the gap between the cone and the pipeline acquires a turbulent motion inside the measuring chamber from forming the cone to the wall of the chamber. The vortex streams of constantly flowing liquid mix it up and create conditions for fluid renewal and self-purification by entrainment of the precipitating particles.

The diameter of the base of the cone exceeds the diameter of the tube of the measuring chamber and protects the lower part of the tubes from the entry of air bubbles into the chamber through the gap. Thus, it is possible to use the acoustic method of measuring and and measuring the accuracy of the conductometric method of measurement.

In addition, the possibility of establishing a gap of various sizes will make it possible to control suspensions with different specific gravities of solid particles.

Extraction of the upper open part of the pipe above the surface of the suspension

causes free access for the installation and maintenance of the sensors and the release into the atmosphere of the vapor-gas mixture with increasing temperature of the suspension.

The drawing shows the device, General view.

The device contains a measuring chamber 1 in the form of a pipe segment and a cone 2 fixed to the lower part of the Pipeline. The cone 0 is reinforced with a gap coaxially with the lower part of the pipeline, pointing inwards with the help of plates at three points. The size of the gap depends on the density of the controlled suspension 5 and is chosen experimentally.

The cone can be solid or hollow with a bottom.

In the upper part of the measuring chamber in the clarified area 0 sensors of electrical conductivity, velocity of ultrasound propagation and temperature are placed.

The device works in the following 5 ways.

The device is installed in a cartridge filter tank, where the suspension is fed from wet grinding mills. The device is placed in suspension between the filter cartridge sections. With forced agitation in the filter container, the suspension acquires a linear speed of movement. Getting through the gap in the lower part of chamber 1, the flow with 5 solid particles moving along

the inclined part of the side surface of the cone 2, changes the direction of motion, the transition to the turbulent regime.

Under the action of gravity, solid particles lose speed and, after settling, are carried away by the flow. The liquid phase, also acquiring turbulent motion in the vertical plane due to its lower density, moves to the upper part of the chamber. The continuous movement of solids and filtrate constantly updates the clarified portion of the filtrate.

A cone, installed in the lower Q part with the tip inward, allows to create vortex flows of continuously flowing liquid and to provide an increase in the speed of mixing of the suspension in the lower part of the pipe, which leads to a decrease in transport

lagging changes in the composition of the liquid-phase in the upper part of the pipe. In addition, the eddy slurry flows that occur when a fluid flow hits a cone / prevents its overgrowing, since solid particles

suspension, acquiring a circular movement from the side surface of the cone constantly cleaned (knock) crystallizing sediment, preventing the formation of films on the surface

Claims (2)

Claim A device for the continuous selection of the liquid phase of the suspension, containing taken into account during the examination 1. USSR author's certificate No. 378750, cl. G 01 N 1/10, 1971. 2. USSR copyright certificate 20 "421922, cl. G 01 K 27/08, 1971.