RU2746866C1 - Automated acid extractor centrifuge for production of cellulose nitrates - Google Patents

Abstract

FIELD: centrifuges.SUBSTANCE: invention relates to centrifuges with pulsating sediment. An automated acid-spinning centrifuge for the production of cellulose nitrates contains housing, a rotor located inside the housing, a frame, a main shaft with a hydraulic cylinder located inside the frame, an oil station and a main shaft drive. The rotor is two-stage. The design of the cascades is a perforated shell with a bottom and filter screens installed inside. The first stage is a pusher. The centrifuge contains a unit for eliminating the decomposition of cellulose nitrates and a device for regulating the frequency of the pusher strokes. The body is connected to the centrifugal collector, contains partitions dividing its internal space into five cavities, a flushing device, and irrigation nozzles. The rotor contains feeding discs with a device for adjusting the gap between them.EFFECT: increased efficiency and safety of the existing production of cellulose nitrates.1 cl, 3 dwg

Description

SUBSTANCE: invention relates to centrifuges with pulsating sediment.

A centrifuge with a pulsating rotor for unloading sediment is known, containing a housing, a feeding device, a device for unloading solid and liquid phases, a rotor equipped with a rotary motion drive, receivers of the clarified and thickened phase, a filter element in the form of a metal sieve, a conical funnel, a disk moving backward - progressively, rod and rotor (Processes and devices of the chemical industry / Romankov P.G., Kurochkina M.I., Mozzherin Yu.Ya.-L .: Chemistry, 1989, p. 145).

The disadvantages of this device include:

- the complexity of the design;

- big sizes;

- impossibility of recuperating the liquid phase due to the absence of washing devices and low efficiency of phase separation.

A centrifuge with pulsating sludge discharge is known, containing a sealed casing, a rotor located inside the casing, a frame having a base and a cover, an oil station, a main shaft with a hydraulic cylinder and a main shaft drive located inside the frame (A.S. No. 591227 dated 08/07/1976) ...

The disadvantages of this centrifuge include:

- the absence of a filter element between the rotor and the pusher of the hydraulic cylinder rod, which does not exclude the carryover of the phase separation product outside the rotor location zone, which, in turn, reduces the efficiency of the installation.

It is known from a centrifuge with pulsating sludge discharge that it contains a sealed casing, a rotor located inside the casing, a frame, a main shaft with a hydraulic cylinder located inside the frame, an oil station and a main shaft drive. In this case, the rotor consists of an outer drum with a perforated shell and a pusher, between which a filter element made of fabric is placed, and the pusher itself is connected to the hydraulic cylinder rod (utility model patent No. 186792 dated June 14, 2017).

The disadvantages of the utility model include:

- impossibility of recuperating the liquid phase due to the lack of washing devices;

- the impossibility of using for separation of media containing a ternary acid mixture with a high concentration of acids, due to the lack of appropriate material design of a fabric filter resistant to the processed environment.

A centrifuge is known from the prior art, which contains a sealed casing, a rotor located inside the casing, a frame, a main shaft with a hydraulic cylinder, an oil station and a main shaft drive located inside the frame, the rotor being a two-stage rotor, the first cascade containing a pusher and filter screens, and the second is a perforated shell with a bottom and with filter screens installed inside, while the rotor is equipped with a feed cone with an equalizing ring and a protective cone, and underwater collectors are attached to the centrifuge casing for supplying flushing liquid to the separation zone (utility model patent No. 171742 dated 14.06. 2017).

We took this device as a prototype.

The disadvantages of the prototype are as follows:

- the cone-shaped shape of the feed and protective cone, which increases the time spent on the passage of the suspension from the loading point to the inner surface of the rotor, and leads both to an increase in the likelihood of clogging of cellulose nitrates in the loading zone, as well as to the complexity of their cleaning;

- the absence of a washing device for removing the remains of cellulose nitrates (hereinafter NC) from the back cover of the housing, adhered during the operation of the centrifuge, leading to an imbalance of the basket;

- the absence of an inspection hatch on the front cover of the centrifuge, which serves simultaneously as an inspection hatch and an ejection surface to relieve excess pressure in case of decomposition of the NC, which increases the risk of an uncontrolled explosion of equipment;

- the absence of a viewing light in the loading device does not allow to visually control the process of feeding the NC into the centrifuge, and it is not possible to quickly eliminate the NC blockage of the centrifuge feeding zone;

- the lack of a device for regulating the gap of the feed and protective cones, which does not allow to adjust the operation of the centrifuge to squeeze out the suspension of various brands of NTs.

The aim of the claimed technical solution is to improve the efficiency and safety of the existing production of NC.

The goal is achieved by the fact that the claimed technical solution contains: a housing located inside the housing, a rotor, a frame, a main shaft with a hydraulic cylinder, an oil station and a drive of the main shaft, located inside the frame, while the rotor is two-stage, and the first cascade performs rotational and reciprocating movements, the second the cascade only rotation, contains a pusher and filter sieves (not shown in the figure), and the second is a perforated shell with a bottom and with filter sieves installed inside, a viewing lamp installed on the loading device, a decomposition elimination unit, and on the front cover of the housing there is inspection hatch (knockout surface), a device for regulating the frequency of the pusher strokes, while the body contains partitions dividing the inner space of the body into five cavities, which exclude mixing of washing solutions of acids, a flushing device to remove the residues of NC from the rear of the rotor and the body, irrigating the nozzle and, for washing the NC from acids, as well as the housing is connected by a centrifugal collector, the rotor contains feed discs with a device for adjusting the gap between them.

FIG. 1 shows the centrifuge body (in section);

in fig. 2 is a front view;

in fig. 3 is a side view,

Where:

an automated acid-extraction centrifuge for the production of cellulose nitrates is made with a protective casing 1 of rotating drives and mechanisms (main shaft with hydraulic cylinder, oil station, main shaft drive is not shown in Fig.);

- with a device for regulating the frequency of strokes of the pusher 3 of the first stage 15 of the rotor 2, which reciprocates. Device 3 is an electrically adjustable valve installed on the oil line;

- with a fugate collector 4, which is a steel box with partitions, on which the gas phase abruptly changes its direction of movement, freeing itself from liquid droplets then flowing into the drain pipeline;

- with a unit for liquidation of decomposition of NTs 5, which in case of decomposition of NTs inside the rotor 2 supplies an acid mixture in large quantities to reduce the temperature of the solid phase, and which is a pipe with a longitudinal conical cut through which the NTs are irrigated;

- with partitions 6 on the inner side of the centrifuge body 16, which prevent mixing of ternary acid mixtures with different concentrations of acids inside the body 16 and carry out their separate output. The partitions are made in the form of steel rings of the corresponding diameter installed between the rotating rotor 2 and the centrifuge body 16, the rings are welded to the body 16 in the places providing the formation of cavities 7 for separate withdrawal of liquids with different concentrations of acids;

- with four irrigation nozzles 8, supplying an acid mixture with a decreasing concentration and water inside the rotor 2 of the centrifuge for washing the solid phase;

- with a device for adjusting the gap 9 between the feeding disks (disks) 10, which allows you to adjust the thickness of the cake NTS and, thereby, to carry out acid extraction of NTS of various brands;

- with feeding disks 10, the flat shape of which ensures the passage of the suspension of the minimum distance from the loading device to the walls of the rotor 2, which reduces the specific volume of the NC located on the disks 10 and, accordingly, the risk of its decomposition, reduces the possibility of clogging the NC located in the loading zone, and so it also simplifies their cleaning;

- with flushing devices 11, to remove the residues of NC from the rear cover of the housing 16, equipped with nozzles that flush the NC from the rear side of the rotor 2 to prevent decomposition of the NC and imbalance of the centrifuge;

- with an inspection hatch 12 on the front cover of the housing 16, which simultaneously serves as an inspection hatch and an ejection surface for relieving excess pressure in the event of decomposition of the NC. The knockout surface is a hatch fixed on the front cover of the centrifuge with the help of special mechanisms that simultaneously open when the design pressure in the centrifuge is exceeded;

- with a loading device 13, equipped with a flow-through inspection lamp 14, for visual control of the feed of the NC suspension in order to regulate the feed pump feeding the suspension and uniform flow of the NC into the interdisk space of the centrifuge;

- the design of the cascades is a perforated shell with a bottom and with filter screens installed inside, the first cascade 15 being a pusher.

The device works as follows:

the main unit of the centrifuge is a two-stage cylindrical rotor 2, cantilevered on the shaft.

The operation of the device begins with the rotation of the electric motor, which transmits the torque to the shaft installed in the bed through the V-belt transmission. The speed is regulated by a frequency converter.

The pusher rod moves inside the shaft in bronze bushings. On the front of the shaft and rod, the cascades of the rotor 2 are installed, and on the back - the hydraulic cylinder. On the front flange of the bed, a body 16 is attached, which has cavities 7 for the centrate and a rectangular flange for unloading the sediment. Attached to the body is a loading device 13 equipped with a flow-through inspection lamp 14, four nozzles 8 for flushing liquid and a centrifugal collector 4.

The reciprocating movement of the pusher is carried out from the hydraulic cylinder, the piston of which is set in motion by supplying oil under pressure from the oil station.

The suspension through the loading device 13, equipped with a flow-through inspection lamp 14, enters the space between the feed discs 10, spins up and centrifugal force, being evenly distributed on the screens of the first cascade 15. The liquid phase of the suspension goes through the screens into the housing 16 and through the centrifuge collector 4 is removed from the centrifuge , and the solid phase remains on the sieves.

As a result of the reciprocating movements of the rod, with the sieves of the first cascade 15 fixed to it, the sludge moves along the sieves of the first cascade using stationary feeding disks 10. As the solid phase moves along the surface of the sieves of the first and second cascade, it is washed with the help of irrigation nozzles 8, and the centrifuge is removed through correspondingly spaced cavities 7 formed by partitions 6 in the housing 16 of the rotor 2 of the centrifuge.

As a result of the strokes, the sediment moves along the entire length of the first cascade 15 of the rotor 2 and is poured onto the sieves of the second cascade.

When the rod moves from the frame, the fluoroplastic scrapers of the screens of the first cascade 15 push the sediment on the screens of the second cascade and move it along the rotor 2 to the unloading hopper (not shown in the figure). When the rod moves to the bed, the sediment is poured from the first cascade 15 to the second.

The moisture content of the sediment is regulated by the number of revolutions of the rotor 2, which is set by the frequency converter, and the number of pulses of the pusher. The number of reciprocating strokes of the pusher is regulated by an electrically adjustable valve installed on the oil line. In addition, the moisture content of the sludge is regulated by the gap between the feeding discs 10.

In case of decomposition of NC in the centrifuge body, a decomposition elimination unit NC 5 is provided, which, in case of decomposition of NC inside the rotor 2, a large amount of acid mixture to reduce the temperature of the solid phase.

The claimed technical solution meets the criteria: novelty, in terms of the totality of distinctive features, inventive step and industrial level, tk. can be used in the production of NC, which is an intermediate product for use in the industry of special chemistry, as well as used to obtain civilian products.

Claims (2)

1. An automated acid-spinning centrifuge for the production of cellulose nitrates, containing a housing, a rotor located inside the housing, a frame, a main shaft with a hydraulic cylinder, an oil station and a main shaft drive located inside the frame, while the rotor is two-stage, the design of the cascades is a perforated shell with a bottom and with filter sieves installed inside, and the first cascade is a pusher, characterized in that it contains a unit for eliminating the decomposition of cellulose nitrates, a device for regulating the frequency of the pusher strokes, the body is connected to a centrifuge collector, contains partitions dividing its internal space into five cavities, a washing device that irrigates nozzles, and the rotor contains supply discs with a device for adjusting the gap between them. 2. The automated acid-spinning centrifuge for the production of cellulose nitrates according to claim 1, characterized in that it contains an inspection light installed on the loading device, a protective cover of the drive and mechanisms, and there is an inspection hatch on the front cover of the housing.

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