Vinylamine reactor outlet pneumatic control valve assembly

Abstract

The utility model relates to the field of chemical engineering automatic control equipment, in particular to a vinylamine reactor outlet pneumatic control valve assembly which comprises a pneumatic high-pressure adjusting angle valve A and a pneumatic high-pressure adjusting angle valve B which are arranged in parallel, and two process valves are respectively connected in series in front of and behind the pneumatic high-pressure adjusting angle valve A and the pneumatic high-pressure adjusting angle valve B; and the controller is electrically connected with the pneumatic high-pressure adjusting angle valve A and the pneumatic high-pressure adjusting angle valve B and is used for switching the pneumatic high-pressure adjusting angle valve A and the pneumatic high-pressure adjusting angle valve B. The utility model has the following beneficial effects: the technical scheme is simple in process, saves a flash tank, a pipeline and auxiliary instruments and facilities, optimizes the field operation layout, and improves the production efficiency. Maintenance is safe, control means are increased, the service life of control is prolonged, maintenance cost is saved, operation can be carried out in an emergency state, and process safety is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of automatic control equipment of chemical industry, especially ethylene amine reactor outlet pneumatic control valve assembly. BACKGROUND

[0002] Ethylene amine production process using ethanol amine method, installs the flash tank 41 to the outlet of reactor, carries out condensation to reactor outlet material. Figure 1 As shown in the figure, the outlet pipeline on the bottom of the flash tank 41 is connected with a single seat pneumatic valve 42, and a liquid level transmitter 43 and a liquid level gauge 44 are installed on the flash tank 41, the single seat pneumatic valve 42 is electrically connected with the liquid level transmitter 43, and is used for adjusting the liquid level of the flash tank 41.

[0003] Because the outlet material of the flash tank exists in the state of high-pressure high-temperature gas-liquid mixture, the regulating valve at this place is in a flash and cavitation state for a long time, the failure rate of the regulating valve is high, and it is difficult to control, and parking is often caused. INVENTION CONTENTS

[0004] The utility model aims at providing a kind of ethylene amine reactor outlet pneumatic control valve assembly, with the characteristics of easy control, low parking risk.

[0005] The above technical purpose of the utility model is realized by the following technical scheme: ethylene amine reactor outlet pneumatic control valve assembly, comprising:

[0006] Pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B, both are connected in parallel, and two process valves are connected in series before and after pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B;

[0007] Controller, electrically connected with pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B, is used to switch pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B.

[0008] As preferred, the actuator of pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B is start-up diaphragm type or piston type.

[0009] As preferred, pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B are accident keeping type.

[0010] As preferred, pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B are both equipped with instrument air storage tank.

[0011] As preferred, pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B both include valve core and valve seat, and valve core and valve seat adopt cascade multistage sealing, with four sealing points.

[0012] As preferred, the cylinder gas path part of pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B is provided with a guard valve.

[0013] Preferably, a blowdown pipe is arranged in front of the pneumatic high-pressure regulating angle valve A and the pneumatic high-pressure regulating angle valve B respectively, and the blowdown pipe is connected to a sewage pool, and two blowdown valves are arranged on each blowdown pipe.

[0014] In summary, the utility model has the following beneficial effects:

[0015] First, the technical scheme has a simple process, saves the flash tank, the pipeline and the auxiliary instrument facilities, and optimizes the field operation layout.

[0016] Second, compared with the previous mode, the double process valves are arranged in front of and behind the pneumatic high-pressure regulating angle valve, so that the process medium can be effectively isolated when the control valve is overhauled, and the overhauling is safer.

[0017] Third, the technical scheme does not cause disturbance to normal production of the device, but increases the control means, that is, even if any one of the pneumatic high-pressure regulating angle valves fails, the other pneumatic high-pressure regulating angle valve can be automatically switched.

[0018] Fourth, in the above technical scheme, the control valve is selected and optimized, that is, the conventional pneumatic single-seat valve is changed into the pneumatic high-pressure regulating angle valve with cascade sealing, so that the service life of the control is prolonged, and the maintenance cost is saved.

[0019] Fifth, in the above technical scheme, the gas circuit of the pneumatic high-pressure regulating angle valve is provided with a guard valve and a gas storage tank, so that the process safety can be ensured in an emergency state. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic diagram of a control valve process before optimization in the background art;

[0021] Figure 2 is a schematic diagram of a control valve process after optimization in the embodiment;

[0022] Figure 3 is a schematic diagram of the appearance of the pneumatic high-pressure regulating angle valve A and the pneumatic high-pressure regulating angle valve B;

[0023] Figure 4 is a sectional view of the pneumatic high-pressure regulating angle valve A and the pneumatic high-pressure regulating angle valve B.

[0024] In the drawings, 11 is the pneumatic high-pressure regulating angle valve A; 12 is the pneumatic high-pressure regulating angle valve B; 13 is a controller; 21 is a feed pipeline; 22 is a discharge pipeline; 31 is a process valve; 32 is a blowdown pipe; 33 is a sewage pool; 34 is a blowdown valve; 41 is a flash tank; 42 is a single-seat pneumatic valve; 43 is a liquid level transmitter; and 44 is a liquid level meter. DETAILED DESCRIPTION

[0025] The utility model will be further explained in detail below in combination with the drawings.

[0026] The embodiments are merely illustrative of the utility model, and are not intended to limit the utility model, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as the modifications are within the scope of the claims of the utility model, they are protected by the patent law.

[0027] Embodiment:

[0028] As Figure 2 The control valve assembly comprises pneumatic high-pressure regulating angle valve A11 and pneumatic high-pressure regulating angle valve B12, both of which have the same parameters and are arranged in parallel, the front ends of both are connected to the ethylene amine feed pipeline 21, and the rear ends are connected to the discharge pipeline 22; in normal production, one of the regulating angle valves is selected at random, and when maintenance is required, the regulating angle valve can be switched to the other one. Since the process medium at the outlet of the flash tank 41 comprises liquid ammonia, hydrogen, ethanol amine and ethylene amine, and the typical feature is gas-liquid mixed phase, the regulating valve at this position is in a flash and cavitation state for a long time, the failure rate of the regulating valve is relatively high, and it is difficult to control, which often causes shutdown. Therefore, the application uses a pneumatic high-pressure regulating angle valve suitable for this working condition, and the flash tank 41, auxiliary equipment and facilities and pipeline arrangement are saved. The valve is of A-B redundant control type, and the control means is improved and the risk of shutdown is reduced by changing the single-loop control of the liquid level before optimization to reactor feed selection control. The pressure before the valve is above 22 MPa, and the pressure after the valve is reduced to below 2 MPa. The pneumatic high-pressure regulating angle valve A11 and the pneumatic high-pressure regulating angle valve B12 are each connected in series with two process valves 31 before and after the valves. A blowdown pipe 32 is arranged before the pneumatic high-pressure regulating angle valve A11 and the pneumatic high-pressure regulating angle valve B12, respectively, and the blowdown pipe 32 is connected to a sewage pool 33. Two blowdown valves 34 are arranged on each blowdown pipe 32.

[0029] The pneumatic high-pressure regulating angle valve A11 and the pneumatic high-pressure regulating angle valve B12 are simultaneously electrically connected with a controller 13, and the controller 13 is used for remotely switching the pneumatic high-pressure regulating angle valve A11 and the pneumatic high-pressure regulating angle valve B12. Remote control of the opening and closing of the valve by the controller 13 belongs to the prior art, and will not be described here.

[0030] The actuator of the pneumatic high-pressure regulating angle valve A11 and the pneumatic high-pressure regulating angle valve B12 is a start-up diaphragm type or a piston type, is of an accident holding type, and is provided with an instrument air storage tank. A guard valve is arranged in the cylinder gas path part of the pneumatic high-pressure regulating angle valve A11 and the pneumatic high-pressure regulating angle valve B12.

[0031] As Figure 3 And Figure 4As shown, the valve inner part sealing form of pneumatic high pressure regulating angle valve A11 and pneumatic high pressure regulating angle valve B12 is cascade multistage sealing, with four sealing points. The valve body material is not less than 316L, the valve inner part material is at least 316L+STL, the valve cover material is at least 316L+STL, the valve body connection mode is flange connection or welding, the valve body pressure resistance grade value is 2500#, the valve body and valve inner part temperature resistance is above 220 DEG C. The valve cover has heat dissipation function, and the packing seal uses flexible graphite. The leakage level of the valve is not less than ANSI V. Because the working conditions of pneumatic high pressure regulating angle valve A11 and pneumatic high pressure regulating angle valve B12 belong to typical flash evaporation with cavitation characteristics harsh working conditions, and the process material has strong corrosion and permeability, therefore the above valve body material is the minimum requirement for this working condition.

[0032] The functions and characteristics of the actuators of pneumatic high pressure regulating angle valve A11 and pneumatic high pressure regulating angle valve B12 are as follows:

[0033] The cylinder is single-acting form, can be kept in case of accident, so the cylinder gas path part must be configured with a security valve, fault position off. The cylinder is configured with a digital intelligent valve positioner, with feedback function, with HART protocol. The cylinder spring is corrosion resistant. The top of the cylinder must be configured with a rain cap, the rain cap is made of stainless steel metal material or metal square bar treatment, with mushroom-shaped built-in exhaust hole. No matter how the valve is installed, all the exhaust nozzles of the cylinder are always arranged downward. The cylinder must be configured with an air filter pressure regulating valve. The air tank at least meets the pneumatic valve 5 times full stroke adjusting action, its accessories at least include a stainless steel on-site pressure gauge (including a stainless steel root valve), a safety valve (including a stainless steel root diameter valve), an inlet end and an outlet end process valve 31, a bottom blowdown valve 34.

Claims

1. An ethylene amine reactor outlet pneumatic control valve assembly characterized by, The utility model relates to a kind of high-pressure pneumatic regulating angle valve, including: Pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B, both are in parallel, and two process valves are connected in series before and after pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B; Controller, electrically connected with pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B, for switching pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B.

2. The ethyleneamine reactor outlet pneumatic control valve assembly of claim 1, wherein, The actuator of pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B is start diaphragm or piston.

3. The ethyleneamine reactor outlet pneumatic control valve assembly of claim 1, wherein, Pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B are accident keeping type.

4. The ethyleneamine reactor outlet pneumatic control valve assembly of claim 1, wherein, Pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B are equipped with instrument air storage tank.

5. The ethyleneamine reactor outlet pneumatic control valve assembly of claim 1, wherein, Pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B include valve core and valve seat, and valve core and valve seat adopt cascade multistage seal, with four sealing points.

6. The ethyleneamine reactor outlet pneumatic control valve assembly of claim 1, wherein, The cylinder gas path part of pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B is provided with guard valve.

7. The ethyleneamine reactor outlet pneumatic control valve assembly of claim 1, wherein, Pneumatic high-pressure regulating angle valve A and pneumatic high-pressure regulating angle valve B are respectively provided with blowdown pipe before, and blowdown pipe is connected to sewage pool, and two blowdown valves are arranged on each blowdown pipe.

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