SI7811166A8 - Self-controlling device for a pneumatic transport of powdery materials - Google Patents

Description

FIELD OF THE INVENTION

The invention relates to a self-regulating device for pneumatically transporting dusty material through pipelines, even when the material is in the form of dust or very fine particles. As such, the invention falls within the field of the technique of Packaging and Transmission of a Mark under the International Patent Classification B65.

Technical problem

Pneumatic transport of powdered or finely ground material causes various problems such as abrasion of the transported material caused by its mixing with the carrier gas stream, which leads to an increase in the mass of the transmission and thus often congestion of the pipeline, ensuring continuous and steady transmission with a permanent optimum flow of material without undesirable delays, congestion, abrasion of transported material and various plant organs. The present invention enables the automatic regulation of pneumatic conveyance of materials, which in addition eliminates any known defects that have accompanied the previously known devices.

The state of the art

Several devices are known for the pneumatic transport of dusted or finely ground material. Thus, for example, in U.S. Pat. 2 822 333 a device is required, which ensures the pneumatic transport of finely ground material and which is provided with a material distributor in the form of a wheel with blades, as well as means for producing pressurized air current, which is introduced into the mixing chamber with the shredded material , in which the chamber is provided with a separating grid, which ensures homogeneous mixing of air or gas, with the material in the intended mixing chamber, having a grid-like partition, which contributes to a uniform distribution of gas or air current through the mass of the material, thus facilitating the transport of these fine particles. However, although this procedure has practical values, it also has many disadvantages, of which it is important to point out a very important fact, which is reflected in the towers, which in this way mix the carrier gas current and the material causes a very strong abrasion of the material, which causes the proportion of fine particles enlarging these very often leads to congestion of the pipeline.

In another device, known from French Patent Document No. 1 152 269, and which represents a significant improvement in the technique of pneumatic transport of sputtered material, it is contemplated to introduce the sputtered material into the transport pipelines by direct supply of fluidized sputtered material from the column in which the sputtered material is is in a constantly hovering state in free air, whereby the pressure of the air blown with the aid of the injector is equalized by the height of the suspended pole of the dusted material. Such a procedure had its good side, which did not require any valves or valves in the fluidization device, thus eliminating material abrasion and frequent shutdowns due to congestion of the pipeline. However, this procedure had its disadvantages and disadvantages, which made it unsuitable for use in all related industries. Specifically, the process had to be regulated in such a way that the dispensing of the dusted material was carried out in quantities below some critical amount, with congestion occurring in the conduit.

In the French patent file no. 2 236 ”58, the Applicants described a device for regulating the flow, that is, the weight of the sputtered material through a pneumatic conveyor piping system, into which a gas stream was introduced, the pressure of which equaled the height of the fluidized mass triggered by the material, and the pressure being weighed to provide a predetermined quantity

41097 gas, which will be commensurate with the amount of dusted material introduced into the fluidization chamber to maintain pressure at the predetermined height in that chamber. Regardless of the improvements achieved, the process could not be carried out without a special regulatory body that mechanically, in contact with the material being transferred, transmitted the control procedures. It was because of this mechanical exposure to the material being transferred that the organ was exposed to abrasion and / or failure.

Description of a solution to a technical problem with a description of the solution pictures

Continuing their research in the field of pneumatic transport of salvaged material, applicants have found a solution in the form of devices for the automatic regulation of pneumatic transport in a suitable transport facility, which, in addition, does not show the disadvantages of previously known devices.

The device according to the invention, for use in a pneumatic conveyor plant, consists of a storage column, in which the transport material is held and at the bottom of which is formed a deposit with a flank at an angle of natural rash, and a shipping section, in which the material is introduced. from the storage chamber and which is equipped with a porous bulkhead for fluid discharge, a pressure gas pipeline, which in certain quantities, is injected by means of an injector over the porous partition in the shipping section, in the direction of the axis of the inlet opening into the transport pipeline and pipeline. for supplying filuidizing gas, the discharge port of which is located below the porous bulkhead in that shipping section.

The device according to the invention works in such a way that, in order to reduce the coal's natural deposition of the deposits at the bottom of the storage chamber, fluidization of the material in the deposit is carried out by passing the gas stream through the porous barrier and through the transport material, and to achieve the desired flow through drainage pipelines, the standardized pressure Pf is determined to rule below the surface of the porous barrier in order to establish a pressure Pc = Pf above that porous barrier, so that with each increase in the pressure Pc above the pressure Pf, the quantity of material shipped increases. decrease in gas flow through porous barrier, under pressure Pf, while in case of decrease in pressure Pc below the pressure Pf, which also reduces the amount of material shipped, there is an increase in gas flow through the porous barrier and through the transport material.

In the apparatus according to the invention, a powder material directly from the lower chamber of the storage column, in which the deposited material is deposited, is introduced into the piping system for the pneumatic transport of the sputtered material. This storage column can be of any shape and volume, for example, can be cylindrical or in the form of a funnel hopper, the upper space of which is maintained at a certain constant pressure.

The transfer of the sputtered material from the storage column to the pneumatic conveying pipeline is carried out by means of a passage or discharge chamber, which, for example, may take the form of a hollow parallelopiped.

The dispensing chamber is provided with material fluidization means consisting of a porous barrier and a fluidising gas injector, as well as means for the pneumatic transport of the dusted material, consisting of a pressure gas pipeline, at the end of which is located an injector with an exhaust opening above the porous fluidization barrier, wherein, at the axial and opposite directions of the injector discharge port, there is an opening of a drainage line for fluidized sputtered material.

In the lower zone of the storage column, which is in connection with the dispatch chamber, while the device is not in operation, a sidewall is formed at a natural rash angle, the size of which depends on the nature and the fineness of the dusted material,

41097 to be transported.

In the apparatus according to the invention, it is adjusted that the edge of the bed formed during the stationary standstill extends tangentially and in contact with the injector of the gas supply line under pressure. The distance between the edge of the slope rate can be easily adjusted by means of an evening device or a smaller reduction in the height of the discharge opening from the storage column above the level of the porous fluidization barrier.

In order for the material of which the deposit consists to flow into the gas stream ejecting from the injector outlet, this dusty material is fluidized by the flow of pressurized gas through a porous fluidization barrier. In this way, the angle of discharge of the deposit is reduced, so that the edge of its foot is moved further beyond the exhaust port for the compressed gas, which erupts from the injector.

In order to allow the fluidization gas to flow through the porous barrier and through the layer of dusted material lying on that barrier and to be fluidized, it is necessary to establish a certain pressure Pf below the porous barrier, which is determined by the type and fineness of the material for transport and according to the minimum height of the sputtered material in the storage column, so it is also necessary to maintain this pressure Pf in the dispatch chamber. When these pressures are established, a state of equilibrium is established at both sides of the porous barrier, between the pressure Pf at the bottom and the pressure Pc at the top of that porous barrier.

Once the predetermined equilibrium between the pressures Pf and Pc is restored, then a gas fluidization stream is maintained through the porous partition and through the deposited sputtering material, which allows the sputtered material to flow into the tube from the injector, which further feeds it into the pipe system of the conveyor. However, if the pressure Pc above the porous barrier rises above the value of the pressure Pf, which rules below the porous barrier, the fluidized gas stream will no longer be able to flow through the porous barrier and through the sputtered material, and thus the injector does not receive the sputtered material. According to the nature of the dust material, the instantaneous difference between the pressure Pc and the pressure Pf, expressed in absolute values, can be only a few percent. This difference in pressures is caused by the collapse of the deposited material in the storage column and inside the dispatch chamber. Immediately afterwards, the conditions for normal operation are restored, which can be represented as sinusoidal oscillations around some normalized value.

When the normalized pressure Pf for fluidization is determined for a certain value of the deposition of the dusted material and is constantly maintained during operation, the pneumatic transport of the dusted material in the manner described above is regulated by itself, ie. automatically, so that transportation takes place regularly and evenly.

The invention will be described in more detail with reference to the accompanying drawings, which show, by way of example, two examples of devices for pneumatically transporting powdered material according to the invention.

As shown in Figure 1, the pneumatic conveying device consists of a receiving chamber 1, a discharge chamber 2, a pipeline? for the compressed gas ending with the gas injector 8, the porous fluidization bulkheads 4 of the pipeline 5 for the fluidizing gas of the pipeline 10 for pneumatic transport and the suction hopper 11.

The receiving chamber 1 is purged and dusted with material from the funnel 14, for example, the conical bottom of a hopper.

While no gas is flowing through the compressed gas line 3 and the fluidizing gas line 5, a layer of sputtered material is established at the bottom of the receiving chamber 1, the discharge rate 6 of which, through its leading edge 7, extends up to close to the gas outlet opening of the injector 8, and the range of this discharge 6 is regulated by the height of the control latch 9 or by the corresponding control assembly.

In the arrangement of elements described above, the transition of the dusted material

41097 from chamber 1 to pipeline 10 for transportation and dispatch is made through the dispatch chamber 2 as soon as a gas current is provided at the intended pressure in the pipeline 3 for the compressed gas and in the pipeline 5 for the fluidizing gas, respectively. Due to this current, a decrease in the coal fluxes of the steppe 6 results in a material dust deposition at the outlet of the intake chamber 1, so that the edge 7 feet (.) Moves far beyond the exhaust port of the gas injector 8.

In order to ensure uniform delivery of certain quantities of dusted material through pipeline 10, a certain pressure Pf must be established in the discharge chamber 2 and in the space 15 below the porous fluidization barrier 4, and this pressure adjustment is performed by the control valve 13 included in the pipeline 5. Above the porous fluidization barrier 4 some pressure Pc is established, the value of which depends on the type of material sputtered, the amount of that material to be transported and the amount of gas pressure in the gas pipeline 3.

As soon as the pressure Pc above the porous fluidization barrier 4 drops below the pressure value Pf in the space 15, a strong flow of gases, which passes through the porous fluidization barrier 4, is established and fluidizes the material on it, which then moves towards the opening of the gas injector 8, where it is being trapped by the gas flow from that injector and being drawn toward the suction funnel 11 of the discharge pipeline 10. In the event of a rise in pressure Pc to above the pressure value Pf for fluidization, the flow of gas decreases or stops altogether, so that the movement of rate 6 of the deposited material slows down. , thereby reducing the delivery of material to the exhaust port of the gas injector 8, or terminating the delivery completely.

From the foregoing, it can be observed that the device according to the invention for pneumatically transporting the sputtered material is fully self-regulating, and that the flow of the transported material through the drainage pipes is about a standard amount per unit time, which is predetermined by the pressure Pf for fluidization, thus eliminating any risk congestion congestion congestion 10.

Figure 2 shows the dispatch device, which consists of two concentric chambers, of which the outer, annular chamber 21 serves as the receiving chamber and the inner, cup-shaped chamber 22 serves as the dispatch chamber. The height of this inner discharge chamber 22 above the porous bulkhead 24 is variable and is adjustable relative to the porous fluidization bulkhead 24. A pipeline 23 for supplying the compressed gases into the gas injector 28 was conducted through the bottom of the inner discharge chamber 22. height relative to the porous fluidization barrier 24, which separates the lower zone of the receiving chamber 21 from the exhaust space 35, which terminates the discharge opening of the fluidization gas line 25 and incorporates a control valve 33. From the upper part of the interior, the discharge chamber 22 extends upstream drainage pipe 30 with suction hopper 31 mounted inside the dispensing chamber 22 in conjunction with the gas injector 28.

As long as no gas flows through the conduit 23 for the compressed gas and the conduit 25 for the fluidizing gas, at the bottom of the receiving chamber 21, around the conical floor, the inner discharge chamber 22, a deposit of sputtered material is formed, whose rash rate 26 surrounds the conical bottom chamber 22, and the deposit extends over the entire surface of the porous fluidization barrier 24. The distance between the front edge 27 of the rash rate 26 and the exhaust opening of the gas injector 28 is controlled by adjusting the relative height of the discharge chamber inlet opening 22 above the porous fluidization barrier 24.

As soon as gas flow is established in the compressed gas pipeline 23 and in the fluidized gas pipeline 25, the dusted material from the receiving chamber 21 is transferred to the cavity of the discharge chamber 22, where it is trapped by gas current from

4109.?.

gas inductor 28 and drawn by that current into the suction hopper 33 and further through the drainage line 30.

In order to maintain the predetermined delivery of the dusted material through the drainage pipe 30, it is necessary to establish a pressure Pf in the space 35 below the porous partition 24, the height of which is regulated by the control valve 33. The fluid for fluidization of the sediment on the porous fluidization partition 24 is passed through the pipeline 25 into the distribution pipe. space 35. As soon as a predetermined pressure Pc is established above the porous fluidization barrier 24, the height of which depends on the flow of propellants through the pipeline 23 and on the amount of sputtered material, there will be a discharge of that material through the drain pipeline 30.

In the event that the pressure level Pc above the fluidizing porous partition 24 drops to below the value of the pressure Pf in the distribution space 35 through the porous partition 24 and through the deposition rate of the deposited material in the receiving chamber 23, a strong gas flow is established, which will cause this deposition. fluidize and drain to the inside of the discharge chamber 22, where it will reach the engagement zone of the gas injector 28, which will blow the entrapped material into the suction funnel 31 and then into the drainage pipe 30. When the pressure Pc rises to above the pressure value Pf, the flow of fluidizing gases it is reduced, and in the extreme case the flow of gas is completely interrupted. From that moment on, the angle of ejection of the deposit and its rate 26 increased greatly, so that the delivery of the dusty material d <gas injector 28 was greatly reduced or stopped altogether.

It can be concluded from the front i2 deposition that, in this case, the dispensing of the dusted material takes place under the conditions of self-regulation, as was the case with the plant shown in Figure 1, so that the dispatching can be performed without any risk that the drainage pipeline 30 will be clogged , iii that the shipping chamber 22 will be filled up and clogged with dusted material._

In an industrial plant according to FIG.

Pneumatic transport of calcined alumina with a grain diameter of 3.50 / u was carried out. The diameter of the storage chamber (1) was 0.40 m and its height was 5.50 m, while the length of the pipeline (10) was 50 m and its diameter was 0.325

m.

Air was used as fluidization gas and for transport, so that the total air flow in pipelines (5) and (3) was 19 Nnf / min.

The fluidization pressure Pf below the fluidization barrier (4) was 0.30 bar, while the pressure in the pipeline (3) 20 sowed air was 0.40 bar.

The mass of the unit so transported was 5.26 t / h.

Claims (2)

PATENT REQUIREMENTS A self-regulating device for the pneumatic transport of dusty material, characterized in that it consists of a vertical receiving chamber (3,21) and a dispatch chamber (2,22) with both a receiving chamber (3,23) and a dispatch chamber (2,22) ) at its bottom by a porous fluidization barrier (4,24) drawn from the fluidization gas space (15,35) to which a fluidized gas supply line (5,25) is fitted, in which a control valve (13,33) is installed ), where a gas pipeline (10.30) was connected to the discharge chamber (2.22) with a suction funnel (11.31) and a gas injector (8) was passed through the bottom of the discharge chamber (2.22). 28) which is connected to the supply pipeline (3,23) and coaxially fitted with the suction funnel (11,31) of the dispatch pipeline (10,30). Device according to claim 1, characterized in that a regulating latch (9) is mounted on the connection opening of the discharge chamber (2), and that the discharge chamber (22) is height-adjustable relative to the porous fluidization barrier (24) ).