RU2708110C1 - Fibrous materials sorting device - Google Patents

Abstract

FIELD: pulp and paper production.SUBSTANCE: invention relates to pulp and paper production and can be used for cleaning fibrous materials. Summary: fibrous materials sorting device includes sorting with gradual loading of sorted fibrous material, mass output through gate valves to purified mass outlet, water inlet and supply through gate valves for flushing of sorts, sensors of input and output pressures of weight of each sort to control pressure difference in them and subsequent decision making, when preset pressure difference is exceeded, it is necessary to flush sortings, flow meters, gate valves for discharge and dilution of waste water from sortings in basins to ensure required concentration and normal operation of next stage of sorting and arrangement of multistage sorting. Positive effect is achieved due to earlier determination of the beginning of pressure grades clogging, smooth flushing with subsequent smooth return to initial optimum mode of pressure grades operation without stopping the device operation process and maintaining sorting in non-salient state, obtaining minimum losses of suitable paper fiber, at the same time, as a result, the quality and performance of the device for sorting fibrous material is increased.EFFECT: technical result consists in improvement of productivity and quality of fibrous suspension sorting.3 cl, 1 dwg

Description

FIELD OF THE INVENTION

The present invention relates to pulp and paper production and can be used for sorting fibrous materials.

State of the art

In the paper industry, pressure sorters are widely used for cleaning paper slurries, which are used for rough and fine sorting. The essence of the sorting process is to pass the waste paper through the holes, the size and shape of which ensures the separation of the particles containing in the mass, while sorting the paper suspension should be subject to a number of conditions, such as the content of contamination in the waste paper, its concentration, productivity [3]. Otherwise, clogging of pressure screening occurs and its efficiency decreases until it stops, the degree of wear of sorting units increases. Therefore, it becomes necessary to wash the sorting with the removal of foreign matter during the sorting process without stopping its operation, while minimizing the discharge of suitable fiber into waste [3, 6].

A known method of sorting fibrous materials [7], in which the pressure transducers continuously change the pressure of the input fluid from a maximum to a minimum, and also continuously change the pressure of the output fluid from a maximum to a minimum while the fiber clogging is destroyed. The disadvantage of this method is the low productivity of sorting due to the variable inlet pressure, and the maximum inlet pressure should be less than optimal than if the sorting worked without changing the inlet pressure, otherwise clogging of the pressure sorting, as well as the absence of washing it [4].

A known method of sorting fibrous materials [8], in which a suspension of cellulose is supplied from the inlet to the outlet of the pump and reduce the pressure to which the paper suspension is subjected and the input stream is controlled by controlled pressure reduction. The disadvantage of this method is the low productivity of sorting by reducing the input pressure when clogging the sorting and the absence of washing it.

Of the known analogues, the closest in technical essence to the present invention and the achieved result is a method of sorting fibrous materials [9], which includes loading the fibrous material into the inner cavity of the sorting element, sorting the fiber through the gaps between the turns of the sorting element, removing the sorting waste through the central outlet of the journal . During the sorting process, the pressure head of the fibrous material is monitored using a pressure gauge and, with the pressure increasing to the maximum value, the fiber materials are stopped loading, the gaps between the turns of the sorting element are reduced, and the water is subsequently supplied through the central inlet with the sorting waste removed through the central outlet followed by the resumption of the sorting process. The disadvantage of this method is the rough control of the input pressure when determining the start of clogging sorting, stopping the sorting process when washing sorting, as well as the possibility of partial washing and, as a consequence, a decrease in its productivity.

SUMMARY OF THE INVENTION

The aim of the present invention is to increase the productivity and sorting quality of the fibrous material. This goal is achieved by the fact that during the sorting operation, the difference between the input and output pressures of the fibrous material is controlled, and when the preset value of the pressure difference in one of the pressure sortings is exceeded, it is washed without stopping the sorting process of the fibrous material as a whole.

This goal is achieved in that the device of fibrous materials containing the loading of fibrous material into the inner cavity of the sorting element, sorting the fiber through the gaps between the turns of the sorting element, while in the process of sorting, the pressure value of the supplied fibrous material is controlled by a pressure gauge and with the pressure increasing to the maximum values carry out the termination of the loading of fibrous materials, followed by the supply of water through the central inlet with the outlet a waste sorting house with water through a central outlet, followed by the resumption of the sorting process.

In a preferred embodiment, the pressure sensors monitor the difference in pressure between the input sorted and the output cleaned mass to determine the start of clogging of the pressure screen, the pressure valve is flushed, the pressure screen is flushed, the waste valve is controlled by the waste valve, the output of the screened mass is regulated by the valve, the output of the cleaned mass is controlled sorting. Using a flow meter, and an adjustable gate valve, diluting with water a paper suspension, the mass concentration in the intermediate waste pool is maintained, which is pumped to the inlet of the next pressure screen. The operation of subsequent sortings is identical to the work of the first pressure sorting. According to the proposed option, with an increase in the pressure difference between the input and output masses, the sorting washing process begins with each step, increasing the water supply for washing it, increasing the waste discharge and reducing the usable mass until the pressure difference becomes the initial one. This will lead to the return from the washing process to the sorting process of the fibrous material, by transferring the adjustable valves of the washing water supply, the output of the cleaned mass, and the discharge of waste into the initial position, which maintains the pressure screening in an unclogged, working condition, while ensuring its optimal mode of operation is not stopping the sorting process as a whole, which distinguishes it from the prototype.

The list of drawings of the invention

In FIG. 1 is a process diagram of a device in accordance with the present invention.

Information confirming the possibility of carrying out the invention

In FIG. 1 is a flow chart of a 3-stage direct sorting model. A device for sorting fibrous materials contains:

- 1 entry flushing water

- 2 entry of fibrous material

- 5, 15, 25 pressure sorting

- 4, 14, 24 adjustable water supply valves for washing sortings 5, 15, 25

- 10, 20 adjustable water supply valves for diluting waste from sorting output 5, 15

- 3, 13, 23 sensors input 6, 16, 26 output pressure of the fibrous material

- 9, 19, 27 adjustable gate valves for the output of the cleaned mass to the output 30

- a flow meter 7, an adjustable gate valve 8 for outputting waste fiber material from sorting 5 into the intermediate pool 11

- a flow meter 17 adjustable valve 18 for outputting waste fiber material from sorting 15 into the intermediate pool 21

-12, 22 pumps for supplying mass from pools 11.21 to the input of sorts 15, 25, respectively

- 28 adjustable waste discharge valve to exit 29 - defective.

Practically any pressure sorting can be used as pressure screening, having an inlet pipe for feeding paper suspension, an inlet for supplying washing water, an outlet pipe for leaving the cleaned mass, and an outlet pipe for dumping waste. The washing process for grades 5, 15 25 is asynchronous in time and can start at any time. The initial position of the elements of the device is as follows:

adjustable valves 4, 14, 24 - closed

Adjustable gate valves 8, 18, 28 - open 5-10% [1]

Adjustable gate valves 9, 19, 27 - open 100%.

The fibrous material enters the pressure screening 5, where it is cleaned. Determining the pressure difference of the fibrous material between the input sensor 3 and the output sensor 6, the pressure sorting 5 is monitored. The established difference between the input and output pressures is optimal and serves as a criterion for the normal, pressure sorting work 5. P = | Pbx | - | Pn | ± δP, where δP is the preset pressure bias, designed to exclude the generation of flushing on / off. With clogging of pressure screening, as a rule, the inlet pressure rises and when the current pressure exceeds a predetermined value Pi> P, the flushing process begins. Simultaneously changes to the same discrete (a small value in% is selected empirically) the operation of the following nodes of the device:

- the adjustable valve 4 opens and the flow of flushing water increases for washing the sorting 5

- the adjustable gate valve 9 closes and the yield of the cleaned mass decreases from sorting 5

- the adjustable gate valve 8 opens and the output of waste from sorting 5 into the pool 11 increases

If the new value of the pressure difference Pi of sorting 5 is greater than or equal to the specified pressure P, then the washing process will continue, i.e. the amount of water supplied for washing the sorting will increase even more, the amount of washing waste from sorting 5 will increase, and the output of the purified mass will decrease at output 30. Those. the adjustable valves 4, 8 will open, and the adjustable valve 9 will close proportionally to the discrete. This will happen until the pressure difference Pi decreases below the preset pressure P. This means that the strainer in the pressure screen is washed and the fibrous material must be returned from the waste outlet to the outlet of the cleaned mass 30. The process of completing the washing of screening 5 by simultaneously changing on the discrete operation of the following device nodes:

- the adjustable valve 4 closes and the flow of rinse water for rinsing the sort 5 decreases

- the adjustable gate valve 9 opens and the supply of the cleaned mass increases from the sorting output 5 to the output 30

- closes the adjustable valve 8 and decreases the yield of waste from sorting 5 into the intermediate pool 11.

The process of completing the flushing will occur until the adjustable valves 4, 8, 9 reach their initial position.

Fibrous material that has not been cleaned in sorting 5 at the waste outlet has an increased value relative to the input mass concentration [1, 4]. The amount of waste is constantly changing, the value of the flow meter 7 is used to control the water supply valve 10, which, by changing its position, maintains a given concentration of paper slurry in the pool 11, necessary for the normal operation of the next sorting 15. The fibrous material from the output of the sorting waste 5 is accumulated in the pool 11. The paper suspension from the intermediate pool 11 by the pump 12 is fed to the input of the sorting 15, which also controls the pressure difference between the input and output material of paper slurry using pressure sensors 13, 16. The work of pressure screening 15 is identical to the work of sorting 5. Fibrous material that has not been cleaned in sorting 15 is accumulated in the pool 21, where it is prepared for the next cleaning in sorting 25, by accumulation, dilution with water and fine-tuning it to the required concentration in the pool 21 with an adjustable valve 20 for supplying water. The paper slurry from the intermediate pool 21 is pumped to the sorting input 25 by a pump 22, which also controls the pressure difference between the input and output materials of the paper slurry using pressure sensors 23, 26. The work of pressure sorting 25 is identical to the work of sorts 5 and 15 with the difference that waste through an adjustable valve 28 is discharged to exit 29 marriage. Maintaining concentration in pools 11 and 21 is ongoing and depends only on the amount of fibrous material entering them. Since the quantity of waste is constantly being selected for suitable fibrous material, it decreases from sorting to sorting. The level is also monitored in the intermediate basins 11, 21 to exclude their overflow.

Thus, unlike analogs, the proposed device for sorting fibrous material prevents the possibility of clogging of pressure screening in its very initial stage, which makes it difficult for the fibrous material to pass through the gaps of the sieve, using smooth adjustment of the transition from the operating mode of sorting to the washing mode and vice versa, which does not entail additional clogging sorting as a result of these transitions. Rinsing does not stop the sorting process of the fibrous material as a whole, and also supports sorting in a clean, non-clogged state, which leads to minimal loss of usable paper fiber, and as a result, the quality and productivity of the device

List of references

1. S.N. Ivanov “Paper Technology”, Moscow, 2006

2. B.Z. Smolyanitsky. Waste paper recycling. M. - Forestry 1980

3. M.V. Vanchakov, A.V. Kuleshov, G.N. Konovalova Technology and equipment for waste paper processing St. Petersburg 2011

4. The technology of pulp and paper production in 3t. SPb, Polytechnic 2004

5. LesPromInform No. 1 (41) 2007. Resource-saving technology for waste paper processing

http://www.lesprominform.ru/jarchive/articles/itemshow/974

6.http: //y-sevastyanova.narod.ru/olderfiles/1/sortirovanie_i_ochistka celljulozv

7. US patent No. 6348130 B1, B21C 9 / 00.19.02.2002,

8. US patent No. 8177937 B2, D21C 7/12, 05/15/2012

9. Patent RU No. 2635792 D21D 5/06 07/01/2017

10. http://sbo-paper.ru/publications/massmedia_pack/paper+recycling/ Paper Wholesalers Union “Paper and Cardboard Processing”.

Claims (3)

1. A device for sorting fibrous material, including pressure screening, to the input of which fibrous material is supplied with a pressure sensor controlling the pressure of the supplied mass using a contact pressure gauge, and with increasing pressure to the limit value, the loading of fibrous materials is stopped, followed by the supply of washing water through the inlet with the removal of waste sorting with water through the outlet and with the subsequent resumption of the sorting process characterized in that from the input the washing water through the first adjustable valve enters the washing inlet of the first sort, the output of the cleaned mass of the first sort is connected to the second pressure sensor and through the second adjustable valve is connected to the output of the cleaned mass, and the waste output of the first sort is connected through the first a flowmeter, a third adjustable valve at the inlet of the first intermediate pool, which also receives rinsing water through a fourth adjustable valve. 2. A device for sorting fibrous material according to claim 1, characterized in that, from the output of the first intermediate pool, the mass is supplied by the first pump to the second sorting input connected to the third pressure sensor, the second sorting washing input is connected to the washing water through the fifth adjustable valve, the outlet is cleaned mass of the second sort is connected to the fourth pressure sensor and through the sixth adjustable valve is connected to the output of the cleaned mass, and the waste output of the second sort is connected through the second flow meter, with dmuyu adjustable valve input to the second intermediate basin in which the washing water is also supplied through eighth adjustable valve. 3. The device for sorting fibrous material according to paragraphs. 1 and 2, characterized in that, from the output of the second intermediate pool, the mass of the second pump is fed to the input of the third sort, connected to the fifth pressure sensor, the washing input of the third sort is connected to the washing water through the ninth adjustable valve, the output of the cleaned mass of the third sort is connected to the sixth sensor pressure and through the tenth adjustable valve is connected to the output of the cleaned mass, and the waste output of the third sort is connected to the reject output through the eleventh adjustable valve.

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