RU2816817C1 - Installation for application of metal coating on powder material by carbonyl method - Google Patents

Abstract

FIELD: various technological processes.

SUBSTANCE: invention relates to application of metal coating on powder material by carbonyl method. Said apparatus comprises, in a closed pipeline, a coating metal carbonyl synthesis reactor and a metal carbonyl decomposition reactor for applying a metal coating on the surface of the powder. Each of the above reactors is installed on a separate vibration mechanism, is made with possibility of gas sampling and is equipped with a filter installed respectively after the synthesis reactor and the decomposition reactor. Said plant also comprises a gas holder, a gas flow purification reactor with the possibility of the purified gas outlet into the atmosphere and a circulation pump, which are placed between two buffer tanks for compensation of gas pulsations, installed after the decomposition reactor. At that, installation is additionally equipped with nitrogen supply system, rotameters for determination of volumetric flow rate of gas of synthesis reactor and decomposition reactor, manometers of synthesis reactor and decomposition reactor and gas analyser for analysis of working gas for content of nickel tetracarbonyl.

EFFECT: higher quality of powder material with applied metal coating.

1 cl, 1 dwg

Description

The invention relates to the field of powder metallurgy and can be used for coating metals, alloys, compounds, in particular for metallization of powder materials using the carbonyl method.

The closest is an installation for applying a metal coating to a powder material using the carbonyl method, containing in a closed pipeline a coating metal carbonyl synthesis reactor and a metal carbonyl decomposition reactor for applying a metal coating to the surface of the powder, installed on a vibration mechanism, with the ability to take gas samples from the synthesis reactor and decomposition reactor, gas flow purification reactor and circulation pump, gas flow purification reactor is configured to release purified gas into the atmosphere, gas flow purification reactor and circulation pump are placed between two buffer tanks to compensate for gas pulsations installed after the decomposition reactor, and a gas holder, means measurements of plant indicators, the synthesis reactor and the decomposition reactor are equipped with filters, each of which is installed respectively after the synthesis reactor and the decomposition reactor (Patent for invention No. 2747204 dated 05.28.2020 IPC B22F 1/02, B22F 1/025, B22F 1/0081, C23C 16/44, С23С 16/4415, С23С 16/16, publ. 04/29/2021 bulletin. No. 13).

The disadvantage of this installation is the low quality of the resulting finished powder material with an applied metal coating due to the large amount of defects in the finished powder material, due to the fact that:

1. There is no calculation of the amount of nickel transferred between the synthesis reactor and the decomposition reactor.

2. Low accuracy of gas flow calculations in the synthesis reactor due to the fact that the gas flow (CO) is measured in front of the synthesis reactor, and to calculate the transferred nickel it is necessary to measure the gas flow that has already passed through the synthesis reactor (since tetracarbonyl gas is formed in the synthesis reactor nickel).

3. Difficulty in taking samples directly from the synthesis reactor and decomposition reactor along sampling lines, due to the peculiarities of the metallization process and the amplitude-frequency characteristics (AFC) of the reactors.

4. Unstable operation of the installation, leading to possible self-ignition during the reaction of CO gas with oxygen between metallization processes, as well as high toxicity of the installation after completion of the metallization process.

5. Increased gas consumption for filling the installation and increased time for filling and unloading powder material.

These disadvantages directly affect the low quality of the powder material and are eliminated by the proposed new design of an installation for applying metal coating to powder material using the carbonyl method.

The technical result to which the invention is aimed is to improve the quality of the resulting powder material with an applied metal coating due to a reduction in the percentage of defects in the finished powder material, which is achieved due to the presence in the installation of a rotameter to determine the volumetric gas flow rate immediately before the decomposition reactor, which makes it possible to measure the flow rate of the already reacted gas, increasing the accuracy of calculations to determine the progress of the process of applying a metal coating to a powder material, by eliminating destabilization of the processes due to the presence of a nitrogen supply system, which eliminates ignition during the reaction of oxygen and CO gas, as well as by reducing the percentage of defects due to the presence of a system in the installation separate gas filling, allowing the individual reactors of the plant to be filled with gas between metal coating processes on the powder material and due to the possibility of sampling gases located after the filters of the synthesis reactor and decomposition reactor.

The technical result is achieved in that an installation for applying a metal coating to a powder material using the carbonyl method, containing in a closed pipeline a coating metal carbonyl synthesis reactor and a metal carbonyl decomposition reactor for applying a metal coating to the surface of the powder, each of the mentioned reactors being installed on a separate vibration mechanism, designed with the ability to take gas samples and equipped with a filter installed respectively after the synthesis reactor and decomposition reactor, as well as a gas flow purification reactor with the ability to release purified gas into the atmosphere and a circulation pump, which are located between two buffer tanks to compensate for gas pulsations installed after the reactor decomposition, and gas holder, unlike the known installation, is additionally equipped with a nitrogen supply system equipped with a fine-tuning reactor, with the possibility of separately purging the installation, synthesis reactor, decomposition reactor and gas holder, rotameters for determining the volumetric gas flow rate of the synthesis reactor and decomposition reactor, reactor pressure gauges synthesis and decomposition reactor for monitoring the working environment in each of the above-mentioned reactors, and a gas analyzer for analyzing the working gas for the content of nickel tetracarbonyl.

The figure shows a schematic diagram of an installation for applying a metal coating to a powder material using the carbonyl method.

In the figure the positions are indicated:

1 - valve for supplying gases to the installation during purging;

2 - valve for releasing gases from the installation into the reactor for purifying the gas flow during purging;

3 - inlet tap of the synthesis reactor bypass system;

4 - output valve of the synthesis reactor bypass system;

5 - outlet valve for purging the synthesis reactor;

6 - inlet valve for purging the synthesis reactor;

7 - inlet valve of the decomposition reactor bypass system;

8 - output valve of the decomposition reactor bypass system;

9 - output valve for purge of the decomposition reactor;

10 - inlet valve for purging the decomposition reactor;

11 - input valve for switching the supply of compressed air for unloading powder from the decomposition reactor;

12 - output valve for switching the supply of compressed air for unloading powder from the decomposition reactor;

13 - gas supply valve No. ₂ to the installation;

14 - valve for supplying gas N ₂ to the decomposition reactor;

15 - gas supply valve N ₂ to the gas tank;

16 - valve for supplying CO gas to the installation;

17 - valve for supplying CO gas to the gas tank;

18 - valve for supplying CO gas to the decomposition reactor;

19 - valve for supplying gas N ₂ to the synthesis reactor;

20 - valve for supplying CO gas to the synthesis reactor;

21 - automatic valve for releasing gases from the installation into the gas flow purification reactor;

22 - _O2 gas sampling valve;

23 - tap for sampling nickel tetracarbonyl gas from the synthesis reactor;

24 - tap for sampling nickel tetracarbonyl gas from the decomposition reactor;

25 - gas supply valve from the gas tank to the installation;

26 - valve for releasing gases from the gas tank into the gas flow purification reactor;

27 - compressed air supply valve for unloading powder from the decomposition reactor;

28 - valve for releasing gases from the synthesis reactor into the gas flow purification reactor during purging;

29 - valve for unloading powder from the decomposition reactor;

30 - closed pipeline;

31 - synthesis reactor;

31a - synthesis reactor filter;

32 - decomposition reactor;

32a - decomposition reactor filter;

33 - gas flow purification reactor;

34 - circulation pump;

35 - buffer capacity

36 - gas tank

37 - N2 gas supply system;

38 - gas fine-tuning reducer N2;

39 - CO gas fine-tuning reducer;

40 - synthesis reactor pressure gauge;

41 - synthesis reactor rotameter;

42 - decomposition reactor pressure gauge;

43 - rotameter of the decomposition reactor;

44 - gas analyzer

The installation for applying a metal coating to a powder material using the carbonyl method contains a closed pipeline 30 in which a coating metal carbonyl synthesis reactor 31 and a metal carbonyl decomposition reactor 32 for applying a metal coating to the surface of the powder are installed.

The synthesis reactor 31 is installed on an individual vibration mechanism. After the synthesis reactor 31, a filter 31a is installed to clean the gas flow from possible particles of the synthesis reactor with subsequent supply to the rotameter 41.

The decomposition reactor 32 is mounted on an individual vibration mechanism. After the decomposition reactor 32, a filter 32a is installed to clean the gas stream from possible particles of the decomposition reactor with subsequent supply to the buffer tank 35.

Filters 31a and 32a prevent the entry of concentrated solid particles when sampling gases. Solid concentrated particles, in the absence of filters, during gas analysis lead to false gas data. The received false data on gases lead to incorrect calculations that are carried out to determine the end time of the process, i.e. optimal mode to obtain a suitable product, otherwise, due to incorrect calculations, a defect will be obtained in the form of a product with a metal coating that is insufficient in size or a defect in the form of a product with an excess metal coating in size.

Installation of reactors 31 and 32 on individual separate vibration mechanisms makes it possible to ensure the uniformity of the created vibro-fluidized layer and move on to improving the quality of the resulting finished powder material.

The installation contains a gas flow purification reactor 33, located after the gas discharge valve from the installation into the gas flow purification reactor during purging 2, an output valve for switching the compressed air supply for unloading powder from the decomposition reactor 12, an automatic gas discharge valve from the gas stream purification reactor installation 21, after valve 26 for discharging gases from the gas holder, after valve for discharging gases 28 from synthesis reactor 31 into gas flow purification reactor 33. Gas flow purification reactor 33 is configured to release purified gas into the atmosphere.

The circulation pump 34 is installed between two buffer tanks 35, which are installed after the decomposition reactor 32. Buffer tanks 35 are necessary to compensate for gas pulsations.

The installation is equipped with a gas holder 36, which is necessary for storing and replenishing the missing CO gas.

The installation additionally contains a nitrogen supply system 37, equipped with a fine-tuning gearbox 38. In this case, the nitrogen supply system is configured to purge both the entire installation and a separate synthesis reactor 31, and a separate decomposition reactor 32, and a gas flow purification reactor 33.

Purge of the synthesis reactor 31 is carried out using valve 5 of the output valve 5 for purge of the synthesis reactor 31, inlet valve 6 for purge of the synthesis reactor 31, valve 19 for supplying gas No. ₂ to the synthesis reactor 31; valve 28 for releasing gases from the synthesis reactor 31 into the gas flow purification reactor 33 during purging.

Nitrogen purging of the decomposition reactor 32 is carried out using the inlet valve 11 for switching the supply of compressed air for unloading powder from the decomposition reactor 32, the output valve for switching the supply of compressed air for unloading powder from the decomposition reactor 32, and the valve 14 for supplying gas N ₂ to the decomposition reactor 32, tap 12 for discharging gases from the decomposition reactor 32 into the gas flow purification reactor 33.

The gas tank 36 is purged with nitrogen through valve 15 for supplying gas N ₂ to the gas tank through valve 26 for discharging gases from the gas tank 36 into the gas flow purification reactor 33.

In this case, it is possible to carry out separate purging of the installation without a synthesis reactor 31, without a decomposition reactor 32, and without a gas tank 36. Such purging is carried out through the N2 gas supply valve 13 into the installation by means of the inlet valve 3 of the synthesis reactor bypass system 31, the output valve 4 of the reactor bypass system synthesis 31, inlet valve 7 of the decomposition reactor bypass system 32, output valve 8 of the decomposition reactor bypass system 32, valve 2 for discharging gases from the installation into the gas flow purification reactor 33 during purging.

The presence of a nitrogen supply system 37 allows for the removal of oxygen from the installation components. To determine the amount of oxygen in the installation, it is necessary to take a gas analysis from tap 22 for sampling O ₂ gas. The oxygen content in the installation is determined as a percentage. For the installation to operate, there must be no more than 0.2% oxygen in the system. To do this, the installation is purged with nitrogen in order to displace oxygen; later the nitrogen will be replaced by carbon monoxide gas (CO - working gas). In this case, the presence of nitrogen gas in the system is not critical. Nitrogen does not allow contact between oxygen and carbon monoxide (CO), as well as the nickel tetracarbonyl gas that appears during operation (TKN - working gas, a synthesis product in the synthesis reactor of 31 carbon monoxide and nickel, TKN is necessary for the decomposition reaction in the decomposition reactor), so otherwise, an explosion reaction will occur under certain conditions that may appear during the operation of the installation if the oxygen content is significant. Thus, the nitrogen supply system 37 makes it possible to stabilize the operation of the entire installation, eliminate spontaneous ignition in the installation, and eliminate the formation of defects, thereby increasing the quality of the resulting powder material.

The gas flow purification reactor contains a system for separately filling the synthesis reactor 31, the decomposition reactor 32 and the gas tank 36 with gas.

The installation is configured to take gas samples from synthesis reactors 31 and decomposition 32 after filters of reactors 31a and 32a, respectively. Samples are taken directly, without separate lines. Such sampling in the installation makes it possible to increase the accuracy of calculations to determine the progress of the process of applying a metal coating to a powder material, which will improve the quality of the resulting powder material.

The installation is also equipped with means for measuring the parameters of the installation; to determine the volumetric gas flow rate, it additionally contains a rotameter 41 of the synthesis reactor 31 and a rotameter 43 of the decomposition reactor 32. In this case, the installation contains a pressure gauge 40 and a rotameter 41 at the entrance to the synthesis reactor 31, a pressure gauge 42 and a rotameter 43 at entrance to the decomposition reactor.

Pressure gauge 40 at the entrance to the synthesis reactor 31 to determine the pressure in the synthesis reactor 31 to control the working environment; if the pressure decreases or exceeds, the process of obtaining the final powder material is impossible.

A rotameter 43 is installed at the entrance to the decomposition reactor 32 to determine the flow of TKN gas going into the decomposition reactor 32 (readings from this rotameter are required to calculate the amount of nickel transferred per hour from the synthesis reactor to the decomposition reactor), allowing you to configure the optimal operating mode of the installation. For example, if the reading on the rotameter 41 of the synthesis reactor 31 is three times greater than on the rotameter 43 of the decomposition reactor 32, then the synthesis and decomposition reactions are equivalent (since in the synthesis reactor 31 the gas decreases in volume, and in the decomposition reactor it increases.

A pressure gauge 42 is installed at the entrance to the decomposition reactor 32 to determine the pressure in the decomposition reactor 32 (the readings of pressure gauges 40 and 42 are required to control the working environment).

An installation for applying metal coating to powder material using the carbonyl method operates as follows.

Nickel powder and nickel shot are placed in synthesis reactor 31.

Powder is placed into the decomposition reactor 32 for subsequent nickel plating.

The heating of the gas flow purification reactor 33 is turned on.

To check the sealing of the installation:

- open valves 13, 1 and valves 6, 5, 10, 9. Using fine-tuning reducer 38, gas N2 (Nitrogen) is supplied to a pressure value of 6 kPa, valves 13 and 1 are closed. When the pressure is maintained, valve 2 is opened to release nitrogen gas into the gas flow purification reactor 33.

To purge the synthesis reactor 31 with Nitrogen gas, valves 19, 28 are opened. Valve 6 is moved to the position for supply to the synthesis reactor 31, valve 5 is moved to the position for the outlet from the synthesis reactor 31. Using a fine-tuning reducer 38, Nitrogen gas is supplied. After purging the synthesis reactor 31, valve 22 is opened to determine the amount of oxygen remaining in the synthesis reactor 31 in %. When the amount of oxygen in synthesis reactor 31 reaches no more than 0.2%, valve 22, 19, 28 is closed.

To purge the synthesis reactor 31 with CO gas, open valves 20, 28. Using a fine-tuning reducer 38, CO gas is supplied until a uniform blue flame appears in the gas flow purification reactor 33. The valve 28 is closed and using a fine-tuning reducer the pressure is set to 2.5 kPa . The valve 20 closes. The synthesis reactor 31 is ready for operation.

Then the decomposition reactor 32 is purged with nitrogen gas. To do this, tap 14 is opened, tap 11 is moved to the position on tap 10, tap 10 is moved to the position on the decomposition reactor 32. Tap 9 is moved to the position on tap 12, tap 12 is moved to the direct position from tap 9. Using a fine-tuning gearbox 38 Nitrogen gas is supplied. After purging the decomposition reactor 32, valve 22 is opened to determine the amount of residue in the oxygen decomposition reactor in %. When the amount of oxygen in the decomposition reactor reaches no more than 0.2%, valves 22, 14 are closed. Valve 11 is moved to position on valve 27, valve 12 is moved to position on valve 29.

After this, the decomposition reactor 32 is purged with CO gas. First, valve 18 opens, valve I is moved to the position on valve 10, valve 12 is moved to the direct position from valve 9. Using a fine-tuning gearbox 38, CO gas is supplied until a uniform blue flame appears in the gas flow purification reactor 33. Valve 12 is moved to position tap 29 and using fine-tuning gearbox 38 set the pressure to 2.5 kPa. The valve 18 is closed, the valve 11 is moved to the position on the valve 27, the valve 12 is moved to the position on the valve 29. The decomposition reactor 38 is ready for operation.

Purging of the installation without synthesis reactor 31 and decomposition reactor 32 with Nitrogen gas is carried out by opening valve 13. Valve 1 is moved to the position on the circulation pump 34, valves 3, 4, 7, 8 are opened. Valve 2 is moved to the position from the buffer tank 35. Using Nitrogen gas is supplied to the fine-tuning reducer 38. After purging the installation without synthesis reactor 31 and decomposition 32, valve 22 is opened to determine the amount of oxygen remaining in the installation without synthesis reactors 31 and decomposition 32 in %. When the amount of oxygen in the decomposition reactor 32 reaches a value of no more than 0.2%, valve 13 is closed, valve 1 is moved to the straight position, valve 3, 4, 7, 8 is closed, valve 2 is moved to the straight position.

Then the installation without synthesis reactor 31 and decomposition 32 is purged with CO gas. To do this, tap 16 is opened, tap 1 is moved to the position on the circulation pump 34, tap 3, 4, 7, 8 is opened, tap 2 is moved to the position from the buffer tank 35. Using the fine-tuning reducer 38, CO gas is supplied until a uniform blue flame appears in the gas flow purification reactor 33. Valve 2 is moved to the straight position and the pressure is set to 2.5 kPa using the fine-tuning reducer 38. Tap 16 is closed, tap 1 is moved to the straight position, taps 3, 4, 7, 8 are closed. The installation is ready for operation.

Blowing gas tank 36 with CO gas: valve 17, 26 opens. Using fine-tuning reducer 38, CO gas is supplied until a uniform blue flame appears in the gas flow purification reactor 33. Valve 26 is closed and using fine-tuning reducer 38, gas tank 36 is filled to the required volume. Tap 17 closes. Gas tank 36 is ready for operation.

When carrying out the process of metallization of powder material, taps 5, 6, 10, 9, 25 are moved to the straight position, the circulation pump 34 is turned on, the heating and vibration of the decomposition reactor 32 is turned on, and the vibration of the synthesis reactor 31 is turned on. During the process, the working gas is analyzed for tetracarbonyl content nickel from synthesis reactor 31 by opening valve 23 to gas analyzer 44. The working gas is also analyzed for nickel tetracarbonyl content from decomposition reactor 32 by opening valve 24 to gas analyzer 44.

After the process is completed, the vibration mechanism and heating in the decomposition reactor 32 are turned off, the vibration mechanism in the synthesis reactor 31 is turned off, the circulation pump 34 is turned off, the synthesis and decomposition reactor is purged with Nitrogen gas until the ignition and combustion of the flame in the gas flow purification reactor 33 completely stops. valve 19 opens, valve 6 is moved to the position on the synthesis reactor 31, valve 28 is opened, valve 5 is moved to the position on valve 28. Nitrogen gas is supplied using fine-tuning reducer 38. At the end of the purge, valve 19, 28 is closed.

Purging the decomposition reactor with Nitrogen gas after metallization is carried out as follows. The valve 14 opens, the valve 11 is moved to the position on the valve 10, the valve 10 is moved to the position on the decomposition reactor, the valve 9 is moved to the position on the valve 12, the valve 12 is moved to the straight position. Using a fine-tuning reducer, Nitrogen gas is supplied until the ignition and combustion of the flame completely stops. The valve 14, 25 is closed, the valve 11 is moved to the straight position, the valve 12 is moved to the position on the valve 29.

The heating of the gas flow purification reactor 33 is turned off.

The resulting powder is discharged from the decomposition reactor 32 with compressed air by opening the valve 29, 27.

For the subsequent startup of the installation, purging with Nitrogen and CO gas will only be required for the synthesis reactor 31 and decomposition reactor 32.

Due to the fact that the installation for applying a metal coating to a powder material using the carbonyl method, containing in a closed pipeline a coating metal carbonyl synthesis reactor and a metal carbonyl decomposition reactor for applying a metal coating to the surface of the powder, each of the mentioned reactors being installed on a separate vibration mechanism, is made with the ability to take gas samples and is equipped with a filter installed respectively after the synthesis reactor and the decomposition reactor, as well as a gas flow purification reactor with the ability to release purified gas into the atmosphere and a circulation pump, which are located between two buffer tanks to compensate for gas pulsations installed after the decomposition reactor , and the gas holder, unlike the known one, the installation is additionally equipped with a nitrogen supply system equipped with a fine-tuning reactor, with the possibility of separately purging the installation, synthesis reactor, decomposition reactor and gas holder, rotameters for determining the volumetric gas flow rate of the synthesis reactor and decomposition reactor, pressure gauges of the synthesis reactor and a decomposition reactor for monitoring the working environment in each of the above-mentioned reactors, and a gas analyzer for analyzing the working gas for the content of nickel tetracarbonyl, an increase in the quality of the resulting powder material with an applied metal coating is achieved due to a decrease in the percentage of defects in the finished powder material.

Claims (1)

An installation for applying a metal coating to a powder material using the carbonyl method, containing in a closed pipeline a coating metal carbonyl synthesis reactor and a metal carbonyl decomposition reactor for applying a metal coating to the surface of the powder, each of the mentioned reactors being installed on a separate vibration mechanism, configured to take gas samples and is equipped with a filter installed respectively after the synthesis reactor and decomposition reactor, as well as a gas flow purification reactor with the possibility of purified gas being released into the atmosphere and a circulation pump, which are located between two buffer tanks to compensate for gas pulsations installed after the decomposition reactor, and a gas holder, different in that it is additionally equipped with a nitrogen supply system equipped with a fine-tuning gearbox, with the possibility of purging separately the installation, synthesis reactor, decomposition reactor and gas tank, rotameters for determining the volumetric gas flow rate of the synthesis reactor and decomposition reactor, pressure gauges of the synthesis reactor and decomposition reactor for control working medium in each of the above reactors, and a gas analyzer for analyzing the working gas for the content of nickel tetracarbonyl.

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