CN215766622U

CN215766622U - Alumina dissolving-out casing heat exchanger

Info

Publication number: CN215766622U
Application number: CN202121703411.9U
Authority: CN
Inventors: 杨林; 邱峰; 邢国春; 王薇
Original assignee: Northeastern University Engineering and Research Institute Co Ltd
Current assignee: Northeastern University Engineering and Research Institute Co Ltd
Priority date: 2021-07-26
Filing date: 2021-07-26
Publication date: 2022-02-08
Anticipated expiration: 2031-07-26

Abstract

The utility model relates to an alumina digestion sleeve heat exchanger, which comprises a plurality of digestion sleeves arranged in a matrix manner, wherein each digestion sleeve comprises an outer pipe, an inner pipe and an anti-impact structure, and the inner pipe is arranged in the outer pipe; the two ends of the outer pipe are connected with end heads to seal the end part of the outer pipe and the outer part of the inner pipe, the other end of each end head is connected with a flange through a conical section, adjacent inner pipes are connected and communicated through a U-shaped pipe and are fastened through the flanges by fasteners; the outer pipe is provided with a plurality of process pipe orifices which are respectively connected with connecting pipes of an inlet or an outlet of the ore pulp; the scour protection structure sets up between inner tube and outer tube, including wear-resisting pipe, wear-resisting pipe support, wear-resisting pipe box is established outside the inner tube, corresponds the technology mouth of pipe position that the ore pulp got into, and wear-resisting pipe support is fixed between wear-resisting pipe and outer tube. The utility model changes the original steam heating into ore pulp self-heating, is provided with an expansion anti-scouring structure, reduces the erosion of the slurry to the heat exchanger and prolongs the service life.

Description

Alumina dissolving-out casing heat exchanger

Technical Field

The utility model belongs to the technical field of metallurgical production, and particularly relates to an alumina dissolution casing heat exchanger.

Background

The dissolution and dilution sub-item in the alumina process is an important link, and the dissolution casing is important equipment in the sub-item. The former process of dissolution and dilution is as follows: desilicication ore pulp → secondary steam preheating section → new steam condensate preheating section → new steam heating section → heat preservation digestion section → digestion flash → digestion ore pulp for dilution.

At present, primary ore pulp is preheated by secondary steam, the secondary steam is connected with a shell pass of a heat exchanger, a sleeve is connected with a tube pass, and the more the number of stages of a flash evaporator is, the more steam is saved by a dissolving-out device. However, heating with steam increases the steam requirement throughout the process.

In the last 80 th century, the alumina Nabo and Ribo alumina plants in Germany adopted the process, and the amount of raw slurry treated by each group of pipelined digestion devices was 40m³And 80m³In two specifications, the dissolution device is called a sleeve type canalization dissolution device. The primary ore pulp is sent into a pipeline through a diaphragm pump and carries out sleeve heat exchange with high-temperature slurry after being heated and dissolved out by fused salt (or steam), thereby achieving the purpose of preheating the primary ore pulp. In the ore pulp preheating section, the outer pipe is generally cold raw ore pulp, and the inner pipe is dissolved high-temperature ore pulp, so that heat can be better recovered. But the technology is not continuously applied because no proper pulp heat exchange equipment exists.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects in the prior art, after the German sleeve type pipeline digester is analyzed and researched, the existing digestion sleeve is improved for improving the energy utilization rate, saving energy and reducing emission, and the original heating mode is improved in the process. The utility model provides an alumina dissolution casing heat exchanger, which changes the original steam heating into ore pulp self-heating, is provided with an expansion scour prevention structure, reduces the erosion of the ore pulp to the heat exchanger, and prolongs the service life.

An alumina digestion sleeve heat exchanger comprises a plurality of digestion sleeves arranged in a matrix manner, wherein each digestion sleeve comprises an outer pipe, an inner pipe and an anti-impact structure, and the inner pipe is arranged in the outer pipe; the two ends of the outer pipe are connected with end heads to seal the end part of the outer pipe and the outer part of the inner pipe, the other end of each end head is connected with a flange through a conical section, adjacent inner pipes are connected and communicated through a U-shaped pipe and are fastened through the flanges by fasteners; the outer pipe is provided with a plurality of process pipe orifices which are respectively connected with connecting pipes of an inlet or an outlet of the ore pulp; the scour protection structure sets up including wear-resisting pipe, wear-resisting pipe support between inner tube and outer tube, wear-resisting pipe box is established outside the inner tube, corresponds the technology mouth of pipe position that the ore pulp got into, and wear-resisting pipe support is fixed between wear-resisting pipe and outer tube.

The number of the inner tubes is three, and the inner tubes are arranged in the outer tube in a regular triangle shape.

The utility model has the beneficial effects that:

1. the heat exchanger provided by the utility model is changed from original steam or condensed water heating into slurry heating, and the dissolution casing pipe is a double-layer convection heat exchange device; namely, the shell side medium is heated slurry, the tube side medium is cold slurry, and the hot slurry is used for heating the cold slurry.

2. By applying the heat exchanger provided by the utility model, a dissolution flash system is omitted, the process flow is greatly simplified, and process equipment is saved; the device greatly reduces the demand on the steam quantity, reduces the heat loss in the system and achieves the effects of energy conservation and emission reduction.

3. The heat exchanger provided by the utility model is provided with the expansion anti-scouring structure, so that erosion of slurry to the inner pipe of the heat exchanger is reduced, and the service life of the heat exchange pipe is prolonged. The scour protection structure is simple in structure, remarkable in effect, convenient to install, economical and practical.

4. An anti-impact structure is arranged between the inner pipe and the outer pipe of the digestion sleeve, namely an anti-impact and wear-resistant structure is provided for the shell side feed inlet, and the service life of the heat exchanger is prolonged.

Drawings

FIG. 1 is a front view of a heat exchanger provided by the present invention;

FIG. 2 is an enlarged partial view of the left end of FIG. 1;

FIG. 3 is a schematic view of the impingement structure of the present invention;

FIG. 4 is a side view of FIG. 3;

wherein the content of the first and second substances,

1-a dissolution casing, 2-an anti-scour structure and 3-a shell side ore pulp inlet connecting pipe; 4-an outer tube; 5-inner tube; 6-wear resistant pipe; 7-wear-resistant pipe support.

Detailed Description

For better understanding of the present invention, the technical solutions and effects of the present invention will be described in detail by the following embodiments with reference to the accompanying drawings.

As shown in fig. 1-2, an alumina digestion sleeve heat exchanger, which is used in an alumina industrial digestion and dilution section, is one of important devices in an alumina process, and comprises a plurality of digestion sleeves 1 arranged in a matrix form, wherein the digestion sleeves 1 comprise an outer pipe 4, an inner pipe 5 and an anti-scouring structure, and the inner pipe 5 is arranged inside the outer pipe 4; the both ends of outer tube 4 are connected with the end and are sealed 4 tip and the inner tube 5 outside with the outer, and the end other end is connected with the flange through the conic section, and adjacent inner tube 5 is connected and communicates with each other through U type union coupling to adopt the fastener to pass through the flange fastening. The outer pipe 4 is provided with a plurality of process pipe orifices for connecting with connecting pipes of an inlet or an outlet of ore pulp, or connecting adjacent outer pipes, and two adjacent outer pipes are connected through a U-shaped pipe. In the embodiment, the number of the inner pipes 5 is three, the inner pipes are arranged in the outer pipe 4 in a regular triangle shape, and a certain pipe interval is satisfied, and the certain pipe interval is calculated according to the center distance of the heat exchange pipe 6-2 in GB/T151-2014 Heat exchanger 6.3.1.2.

Because the feeding of sleeve pipe shell side is changed into the ore pulp by steam, its erosion to inner tube 5 aggravates greatly, and is very serious to the corruption of inner tube 5, in order to alleviate, protect inner tube 5 not corroded the destruction, guarantees life, the heat exchanger is provided with scour protection structure 2, plays the effect of protection, prevention erosion to inner tube 5. As shown in fig. 3-4, the erosion prevention structure 2 is disposed between the inner tube 5 and the outer tube 4, and includes a wear-resistant tube 6 and a wear-resistant tube support 7, in this embodiment, the wear-resistant tube is made of hard alloy; the wear-resistant pipe 6 is sleeved outside the inner pipe 5 and corresponds to the position of a process pipe orifice through which ore pulp enters, and the wear-resistant pipe support 7 is fixed between the wear-resistant pipe 6 and the outer pipe 4. The anti-scouring structure 2 prevents ore pulp from directly scouring the inner pipe 5 but scours the wear-resistant pipe 6, and then radial scouring is changed into axial flow, so that the inner pipe 5 is protected and is not seriously corroded.

In this embodiment, the outer tube 4 is provided with two process tube openings.

During heat exchange, cold ore pulp is introduced into the inner pipe 5 and flows in the matrix-type dissolution sleeve 1, the ore pulp with certain heat enters the heat exchanger from the shell side ore pulp inlet connecting pipe 3, the ore pulp is scoured on the wear-resistant pipe 6 through the shell side ore pulp inlet connecting pipe 3, then the radial scouring along the shell side ore pulp inlet connecting pipe 3 is changed into axial scouring along the outer part of the inner pipe 5, the heat exchange is carried out with the cold ore pulp in the inner pipe 5, and finally the cold ore pulp flows out of a process pipe orifice connected with the connecting pipe of an ore pulp outlet on the outer pipe 4.

Claims

1. An alumina dissolution casing heat exchanger is characterized in that: the digestion device comprises a plurality of digestion sleeves arranged in a matrix manner, wherein each digestion sleeve comprises an outer pipe, an inner pipe and an anti-impact structure, and the inner pipe is arranged in the outer pipe; the two ends of the outer pipe are connected with end heads to seal the end part of the outer pipe and the outer part of the inner pipe, the other end of each end head is connected with a flange through a conical section, adjacent inner pipes are connected and communicated through a U-shaped pipe and are fastened through the flanges by fasteners; the outer pipe is provided with a plurality of process pipe orifices which are respectively connected with connecting pipes of an inlet or an outlet of the ore pulp; the scour protection structure sets up including wear-resisting pipe, wear-resisting pipe support between inner tube and outer tube, wear-resisting pipe box is established outside the inner tube, corresponds the technology mouth of pipe position that the ore pulp got into, and wear-resisting pipe support is fixed between wear-resisting pipe and outer tube.

2. The alumina-digestion double-tube heat exchanger according to claim 1, characterized in that: the number of the inner tubes is three, and the inner tubes are arranged in the outer tube in a regular triangle shape.