CN218339000U

CN218339000U - Secondary steam pipeline structure of acid bath multistage flash system and shell pass flushing system

Info

Publication number: CN218339000U
Application number: CN202221674041.5U
Authority: CN
Inventors: 梁翌; 王梅娟
Original assignee: Jinguang Fiber Jiangsu Co ltd
Current assignee: Jinguang Fiber Jiangsu Co ltd
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2023-01-20
Anticipated expiration: 2032-06-30

Abstract

The utility model discloses a multistage flash distillation system's of acid bath secondary steam pipeline structure and shell side rinse-system, the one end of secondary steam pipeline and the steam inlet of preheater are connected, and the other end is connected with the play steam port of evaporimeter, the secondary steam pipeline is including the first horizontal pipe, first return bend, first vertical pipe, second return bend, second horizontal pipe, the third return bend that connect gradually to and the vertical pipe of second, wherein the second horizontal pipe is established in the top horizontal line top position of preheater. In the backwash liquid in the preheater, overflowing backwash liquid can not be stored in the first horizontal pipe in a large amount, and only one part of the backwash liquid can go upwards along the first vertical pipe and can not reach the tail end of the first vertical pipe, so that the backwash liquid can not reach the evaporator, and the effect of preventing overflowing backwash liquid from entering the evaporator is achieved. The utility model discloses do not use the butterfly valve on the secondary steam pipeline, through the change of structure, effectively prevent backwash liquid refluence to the evaporimeter in to investment cost has been reduced.

Description

Secondary steam pipeline structure of acid bath multistage flash system and shell pass flushing system

Technical Field

The utility model relates to a, especially, relate to a secondary steam pipeline structure and multistage flash distillation system of acid bath.

Background

When the shell pass backwashing of the preheater is carried out in the current multistage flash evaporation system, backwash liquid enters the shell pass of the preheater from a backwash liquid inlet pipeline, flows to the preheater at the tail end in sequence after the shell pass of the preheater is filled, and the backwash liquid enters the shell pass of a surface condenser cleaning surface condenser after the backwash liquid at the tail end comes out from a backwash liquid outlet at the tail end, and then returns to a backwash liquid tank, so that the circulation is formed for cleaning the shell pass of the preheater. In the process, as the corresponding evaporator is connected with the shell pass of the preheater through the secondary steam pipeline, backwash liquid can enter the evaporator, in order to avoid the backwash liquid from entering the evaporator, a butterfly valve is installed on the secondary steam pipeline, the valve is closed when the shell pass of the preheater is cleaned, but the valve is fully opened in daily production, namely the valve is specially used for the backwash process of the preheater, the use frequency is not high, the valve is operated once every month, because the caliber of the secondary steam pipeline is relatively large, the investment of fixed assets is increased, the investment of projects is increased, if the valve is not closed tightly or damaged, the valve needs to be replaced, and the operation cost is also increased.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: the utility model aims at providing a reduce cost and the high multistage flash distillation system's of acid bath secondary steam pipeline structure of stability, another purpose of the utility model is to provide a shell side rinse-system who contains above-mentioned secondary steam pipeline.

The technical scheme is as follows: the utility model discloses a multistage flash distillation system's of acid bath secondary steam pipeline structure, the one end of secondary steam pipeline is connected with the steam inlet of pre-heater, and the other end is connected with the play steam port of evaporimeter, the secondary steam pipeline is including the first horizontal pipe, first return bend, first vertical pipe, second return bend, second horizontal pipe, the third return bend that connect gradually to and the vertical pipe of second, wherein the second horizontal pipe is established in the top water flat line top position of pre-heater.

Further, the length of the first horizontal tube is less than the length of any one of the first vertical tube, the second horizontal tube, and the second vertical tube.

Further, the length of the second vertical pipe is greater than the length of the first vertical pipe.

Furthermore, the elbow radii of the first elbow pipe, the second elbow pipe and the third elbow pipe are equal to the pipe diameter.

Further, the length of the first vertical pipe is 2.47 to 12.5 times the length of the second horizontal pipe.

In another aspect, the shell-side flush system of the present invention includes the above-described piping structure.

Furthermore, the shell pass flushing system comprises a plurality of groups of preheaters, secondary steam pipelines and evaporators, and a demister is arranged between each evaporator and each secondary steam pipeline.

The utility model discloses a working process: backwash liquid in the preheater, partly flow along the backwash liquid pipeline, partly can spill over from the steam inlet of preheater and get into the secondary steam pipeline, because the setting of first horizontal pipe is very short, spill over backwash liquid and can't be preserved in a large number in first horizontal pipe, only can partly upwards walk along first vertical pipe, nevertheless because the volume that spills over backwash liquid is limited, can't reach the end of a vertical pipe, and then can't reach in the evaporimeter to the effect that the backwash liquid that has prevented to spill over gets into the evaporimeter has been played.

Has the advantages that: compared with the prior art, the utility model has the advantages of as follows: a butterfly valve is not used on a secondary steam pipeline, backwash liquid is effectively prevented from flowing back to an evaporator through structural change, so that investment cost is reduced, a twelve-stage flash evaporation system is used in a 25 ten thousand/a cellulose fiber project acid station workshop in the viscose fiber industry as an example, 15 sets of flash evaporation systems are used in the project, each set of flash evaporation system is cancelled with the butterfly valve, about 15 ten thousand yuan can be reduced, and about 225 thousand yuan can be reduced in the whole project.

Drawings

FIG. 1 is a schematic view of the structure of the secondary steam pipeline of the present invention;

FIG. 2 is a shell side backwash flow chart of the preheater of the flash evaporation system of the present invention;

reference numeral, 1, a preheater; 2. an evaporator; 3. a demister; 4. a secondary steam line; 41. a first horizontal tube; 42. a first bend pipe; 43. a first vertical tube; 44. a second bend pipe; 45. a second horizontal tube; 46. a third bend; 47. a second vertical tube; 5. a heater; 6. a flushing fluid tank; 7. a washing liquid pump; 8. a surface condenser; 9. a gas-liquid separator.

Detailed Description

The technical solution of the present invention will be further explained with reference to the accompanying drawings.

As shown in fig. 1, the present embodiment provides a secondary steam pipeline structure of an acid bath multistage flash evaporation system, where the secondary steam pipeline 4 includes a first horizontal pipe 41, a first elbow pipe 42, a first vertical pipe 43, a second elbow pipe 44, a second horizontal pipe 45, a third elbow pipe 46, and a second vertical pipe 47, where one end of the first horizontal pipe 41 is connected to a steam inlet of a preheater 1 in the acid bath multistage flash evaporation system, the other end of the first elbow pipe 42 is connected to one end of the first elbow pipe 42, the other end of the first elbow pipe 42 is connected to one end of the first vertical pipe 43, the other end of the first vertical pipe 43 is connected to one end of the second elbow pipe 44, the other end of the second elbow pipe 44 is connected to one end of the second horizontal pipe 45, the other end of the second horizontal pipe 45 is connected to one end of the third elbow pipe 46, the other end of the third elbow pipe 46 is connected to one end of the second vertical pipe 47, and the other end of the second vertical pipe 47 is connected to a steam outlet of an evaporator 2.

Specifically, in the secondary steam pipeline structure, in order to reduce the alkali liquor entering the pipe section during backwashing, the first horizontal pipe 41 is set as short as possible; the first elbow pipe 42 and the second elbow pipe 44 are used for pipeline transition, and the smooth transition of each elbow is kept, wherein the elbow radius R of the first elbow pipe 42 and the second elbow pipe 44 is equal to the pipe diameter D, the second horizontal pipe 45 is arranged above the top horizontal line of the preheater 1, and the length of the first horizontal pipe 41 is smaller than that of any one of the first vertical pipe 43, the second horizontal pipe 45 and the second vertical pipe 47; the length of the second vertical pipe 47 is greater than the length of the first vertical pipe 43; the length of the first vertical pipe 43 is 2.47 to 12.5 times the length of the second horizontal pipe 45.

As shown in fig. 2, the present embodiment is illustrated with a shell-side rinse system containing 12 pre-heaters 1, 14

evaporators

2 and 4 surface condensers 8.

The embodiment provides a shell side flushing system of an acid bath multistage flash system, which comprises a preheater 1, an evaporator 2, a demister 3, a secondary steam pipeline 4, a heater 5, a flushing liquid tank 6, a flushing liquid pump 7, a surface condenser 8 and a gas-liquid separator 9.

In the shell pass flushing system, 12 pre-heaters 1 are connected through backwash liquid pipelines in sequence, the liquid outlets of the pre-heaters 1 located at the head and the flushing liquid tanks 6 are connected through backwash liquid pipelines, the pre-heaters 1 located at the tail ends are connected with surface condensers 8, the surface condensers 8 are connected through backwash liquid pipelines, the surface condensers 8 located at the tail ends are connected with gas-liquid separators 9 through backwash liquid pipelines, and the gas-liquid separators 9 are connected with the liquid inlets of the flushing liquid tanks 6 through backwash liquid pipelines.

Except the preheater 1 positioned at the head, the other preheaters 1 are respectively communicated with corresponding evaporators in the evaporators 2 through a secondary steam pipeline 4, the evaporators 2 which are not communicated with the preheaters 1 are communicated with a surface condenser 8 through steam pipelines, the communicated steam pipelines are provided with butterfly valves, the secondary steam pipelines 4 between the preheaters 1 and the evaporators 2 are not provided with butterfly valves, and through the communication of a first horizontal pipe 41, a first bent pipe 42, a first vertical pipe 43, a second bent pipe 44, a second horizontal pipe 45, a third bent pipe 46 and a second vertical pipe 47, the backwashing liquid is effectively prevented from flowing back to the evaporators 2 from the steam pipelines under the condition that the butterfly valves are not arranged.

When the acid bath multistage flash system carries out backwashing on the shell side of the preheater 1, the trend of backwashing liquid is as follows: the backwash liquid enters the shell pass of the preheater 1 positioned at the front end from the backwash liquid inlet pipeline, flows to the preheater 1 at the tail end in sequence after the shell pass of the preheater 1 at the front end is filled, and after the backwash liquid comes out from the backwash liquid outlet of the preheater 1 at the tail end, the backwash liquid enters the surface condensers 8 connected with each other in sequence to clean the shell pass of the surface condensers, and then returns to the backwash liquid tank 6, and the backwash liquid in the backwash liquid tank 6 is pumped into the shell pass of the preheater 1 positioned at the front end through the flushing liquid pump 7, so that circulation is formed to clean the shell pass of the preheater 1.

The secondary steam pipeline 4 of the embodiment is used as follows: acid bath multistage flash system is when carrying out 1 shell side backwash of preheater, the butterfly valve is not established to preheater 1 and the steam conduit of evaporimeter 2, reform transform the steam conduit into secondary steam conduit 4, backwash liquid in preheater 1, some flows along the backwash liquid pipeline, partly can spill over from the steam inlet of preheater 1 and get into secondary steam conduit 4, because the setting of first horizontal pipe 41 is very short, spill over backwash liquid and can't leave in a large amount in first horizontal pipe 41, only can partly upwards walk along first vertical pipe 43, but because the volume of spilling over backwash liquid is limited, can't reach the end of a vertical pipe 43, and then can't reach in evaporimeter 2, thereby played the effect that prevents to spill over backwash liquid and get into evaporimeter 2.

In order to prevent the backwash liquid from reaching the end of the first vertical pipe 43, the service conditions and the length and height of the secondary steam pipe need to be limited, and the limited conditions and length and height can be calculated according to the formula disclosed in the handbook of chemical pipelines and the prior art. Calculate for 90mbar with water ring vacuum pump vacuum degree, reachs the utility model discloses the limiting condition that well secondary steam pipeline used to compare with the ordinary secondary steam pipeline who establishes the butterfly valve with adding, data in the following table are obtained.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

From the above table can see, in the utility model discloses in raise the secondary steam pipeline 4 between preheater 1 and evaporimeter 2 at preheater 1 entry, keep the first horizontal pipe 41 of preheater 1 entry as short as possible simultaneously, keep the smooth transition of each elbow simultaneously, elbow radius R = pipe diameter D, just so can cancel original butterfly valve, secondary steam is compared with before and must not exceed 60% at this section's pressure loss simultaneously, this limit value is calculated for 90mbar with the water ring vacuum pump vacuum degree that present system used, change the corresponding recalculation if the condition, just so can not influence the system operation, vertical pipe section difference in height between preheater 1 and the secondary steam pipe section 4 also has corresponding restriction, so both guaranteed that the preheater can normal production and backwash, the investment and the operation cost of production line have also been reduced.

Claims

1. The utility model provides a multistage flash distillation system's of acid bath secondary steam pipeline structure, its characterized in that, the one end of secondary steam pipeline (4) is connected with the steam inlet of preheater (1), and the other end is connected with the play steam port of evaporimeter (2), secondary steam pipeline (4) are including first horizontal pipe (41), first return bend (42), first vertical pipe (43), second return bend (44), second horizontal pipe (45), third return bend (46) that connect gradually to and second vertical pipe (47), and wherein the top level line top position at preheater (1) is established to second horizontal pipe (45).

2. The secondary steam piping structure of the acid bath multi-stage flash system according to claim 1, wherein the length of the first horizontal pipe (41) is smaller than the length of any one of the first vertical pipe (43), the second horizontal pipe (45), and the second vertical pipe (47).

3. The secondary steam piping structure of an acid bath multi-stage flash system according to claim 1, wherein the length of the second vertical pipe (47) is greater than the length of the first vertical pipe (43).

4. The secondary steam piping structure of an acid bath multi-stage flash system according to claim 1, wherein the elbow radii of the first elbow (42), the second elbow (44), and the third elbow (46) are equal to the pipe diameter.

5. The secondary steam piping structure of the acid bath multi-stage flash system according to claim 1, wherein the length of the first vertical pipe (43) is 2.47 to 12.5 times the length of the second horizontal pipe (45).

6. A shell side flushing system, characterized in that it comprises a pipe structure according to any one of claims 1-5.

7. The shell-side flushing system of claim 6, comprising a plurality of sets of preheaters (1), secondary steam pipes (4) and evaporators (2), wherein a demister (3) is arranged between the evaporators (2) and the secondary steam pipes (4).