A small scale freezing seawater desalination crystallizer

Abstract

A small frozen seawater desalination crystallizer includes an upper end bearing, an upper end cover, a rotating shaft, a lower end cover, a lower end bearing, a fixed tube plate, a shell, an outer layer crystallization tube, an inner layer crystallization tube, an annular plate, an inner scraper, an outer scraper, a tool holder, a refrigerant inlet pipe, a refrigerant outlet pipe, a conveying pipe, a water inlet pipe, a first outlet ice water pipe, a second outlet ice water pipe and a variable frequency motor. The device mainly completes the freezing crystallization desalination of seawater through the continuous indirect heat exchange between the seawater in the inner layer crystallization tube and the seawater outside the outer layer crystallization tube and the refrigerant between the inner and outer layers of the crystallization tube, realizes the continuous ice formation of the inner and outer layers of the crystallization tube at the same time by the refrigerant, increases the heat exchange area and improves the heat exchange efficiency, and has great industrial application prospect.

Description

Technical Field

[0001] This invention patent relates to the field of seawater desalination, and more particularly to a small-scale frozen seawater desalination crystallizer. Background Technology

[0002] The vast majority of Earth's water resources exist in the form of seawater, making seawater desalination a crucial method for producing fresh water. Seawater desalination mainly employs methods such as distillation, membrane methods, reverse osmosis, and freezing. In the seawater freeze-desalination process, the crystallizer is a vital component. Currently, crystallizers are mainly of two types: direct and indirect. Indirect crystallizers primarily consist of a scraper and a crystallization tube. If the scraper rotates, the crystallization tube remains stationary, and vice versa. In existing crystallizers, seawater typically crystallizes inside or on the outer layer of the crystallization tube, resulting in a small heat exchange area and low heat exchange efficiency.

[0003] In the existing technology, the crystallizer disclosed in Chinese patent CN105600859A relies on a motor to drive multiple scrapers through a belt pulley, which has low transmission efficiency. Increasing the number of crystallization tubes to increase the heat exchange area results in a complex structure. The refrigerant between the shell and the crystallization tubes comes into contact with the atmosphere, resulting in the loss of some energy and a relatively low cold energy utilization rate. Summary of the Invention

[0004] The problem to be solved by this invention is to overcome the shortcomings and deficiencies of the prior art. This device completes the freezing, crystallization and desalination of seawater by continuously and indirectly exchanging heat between the seawater inside the inner crystallizer tube and the seawater outside the outer crystallizer tube with the refrigerant between the inner and outer layers of the crystallizer tube. This achieves simultaneous and continuous freezing of the inner and outer layers of the crystallizer tube by the refrigerant, increases the heat exchange area, improves the heat exchange efficiency, and has a small size and compact structure, which has great prospects for industrial application.

[0005] The present invention is accomplished through the following technical solution: a small-scale frozen seawater desalination crystallizer includes an upper end bearing (1), an upper end cover (2), a rotating shaft (3), a lower end cover (4), a lower end bearing (5), a fixed tube sheet (6), a shell (7), an outer crystallization tube (8), an inner crystallization tube (9), an annular plate (10), an inner scraper (11), an outer scraper (12), a blade holder (13), a refrigerant inlet pipe (14), a refrigerant outlet pipe (15), a conveying pipe (16), a water inlet pipe (17), a first outlet ice water pipe (18), a second outlet ice water pipe (19), and a variable frequency motor (20). The inner crystallizer tube (9) passes through and is fixed on the fixed tube plate (6). The top end cap (2) is fixed to the top end with screws. The upper side end is provided with a first outlet chilled water pipe (18). The outer crystallizer tube (8) is sleeved on the outside of the inner crystallizer tube (9) and fixed on the fixed tube plate (6). The lower end of the outer crystallizer tube (8) and the lower end of the inner crystallizer tube (9) are sealed by welding with an annular plate (10). The fixed tube plate (6) is provided with a refrigerant inlet pipe (14) and a refrigerant outlet pipe (15) located between the outer crystallizer tube (8) and the inner crystallizer tube (9). The conveying pipe (16) is connected to the refrigerant inlet pipe (14). There are 12 pipes, which are evenly distributed between the outer crystallizer tube (8) and the inner crystallizer tube (9). The fixed tube plate (6) and the lower end cap (4) are fixed on the shell (7) with screws. The lower end of the shell (7) is provided with a water inlet pipe (17), and the upper side end is provided with a second outlet chilled water pipe (19).

[0006] The rotating shaft (3) is located in the inner crystallization tube (9) and is fixed by the upper bearing (1) of the upper end cap (2) and the lower bearing (5) of the lower end cap (4); the inner scraper (11) is fixed on the rotating shaft (3) to peel off the ice crystals inside the inner crystallization tube (9), and the number is 4; the knife holder (13) is fixed on the rotating shaft (3) located at the lower end of the inner scraper (11); the outer scraper (12) is fixed on the knife holder (13) to peel off the ice crystals outside the outer crystallization tube (8), and the number is 4; the variable frequency motor (20) rotates the inner scraper (11) and the outer scraper (12) on the knife holder (13) through the rotating shaft (3).

[0007] The beneficial effects of this invention are: 1. This device mainly achieves seawater freezing and crystallization desalination by continuously and indirectly exchanging heat between the seawater inside the inner crystallization tube and the seawater outside the outer crystallization tube with the refrigerant between the inner and outer layers of the crystallization tube; 2. This device realizes continuous freezing of the refrigerant with the inner and outer layers, increases the heat exchange area, improves the heat exchange efficiency, has a compact structure, and has great industrial application prospects. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of the present invention.

[0009] Figure 2 yes Figure 1 AA cross-section view.

[0010] The labels in the attached diagram are as follows: 1-Upper bearing; 2-Upper end cover; 3-Rotating shaft; 4-Lower end cover; 5-Lower bearing; 6-Fixed tube sheet; 7-Shell; 8-Outer crystallizer tube; 9-Inner crystallizer tube; 10-Annular plate; 11-Inner scraper; 12-Outer scraper; 13-Scraper holder; 14-Refrigerant inlet pipe; 15-Refrigerant outlet pipe; 16-Transfer pipe; 17-Water inlet pipe; 18-First outlet chilled water pipe; 19-Second outlet chilled water pipe; 20-Variable frequency motor. Detailed Implementation

[0011] The invention will now be described in detail with reference to the accompanying drawings: as shown in the drawings Figures 1 to 2 As shown, a small-scale frozen seawater desalination crystallizer includes an upper end bearing (1), an upper end cover (2), a rotating shaft (3), a lower end cover (4), a lower end bearing (5), a fixed tube sheet (6), a shell (7), an outer crystallization tube (8), an inner crystallization tube (9), an annular plate (10), an inner scraper (11), an outer scraper (12), a blade holder (13), a refrigerant inlet pipe (14), a refrigerant outlet pipe (15), a conveying pipe (16), a water inlet pipe (17), a first outlet ice water pipe (18), a second outlet ice water pipe (19), and a variable frequency motor (20). The inner crystallizer tube (9) passes through and is fixed on the fixed tube plate (6). The top end cap (2) is fixed to the top end with screws. The upper side end is provided with a first outlet chilled water pipe (18). The outer crystallizer tube (8) is sleeved on the outside of the inner crystallizer tube (9) and fixed on the fixed tube plate (6). The lower end of the outer crystallizer tube (8) and the lower end of the inner crystallizer tube (9) are sealed by welding with an annular plate (10). The fixed tube plate (6) is provided with a refrigerant inlet pipe (14) and a refrigerant outlet pipe (15) located between the outer crystallizer tube (8) and the inner crystallizer tube (9). The conveying pipe (16) is connected to the refrigerant inlet pipe (14). There are 12 pipes, which are evenly distributed between the outer crystallizer tube (8) and the inner crystallizer tube (9). The fixed tube plate (6) and the lower end cap (4) are fixed on the shell (7) with screws. The lower end of the shell (7) is provided with a water inlet pipe (17), and the upper side end is provided with a second outlet chilled water pipe (19).

[0012] The rotating shaft (3) is located in the inner crystallization tube (9) and is fixed by the upper bearing (1) of the upper end cap (2) and the lower bearing (5) of the lower end cap (4); the inner scraper (11) is fixed on the rotating shaft (3) to peel off the ice crystals inside the inner crystallization tube (9), and the number is 4; the knife holder (13) is fixed on the rotating shaft (3) located at the lower end of the inner scraper (11); the outer scraper (12) is fixed on the knife holder (13) to peel off the ice crystals outside the outer crystallization tube (8), and the number is 4; the variable frequency motor (20) rotates the inner scraper (11) and the outer scraper (12) on the knife holder (13) through the rotating shaft (3).

[0013] The working principle of this invention is as follows: During operation, the refrigerant enters from the refrigerant inlet pipe (14) located between the outer crystal tube (8) and the inner crystal tube (9), and is transported to the bottom end between the outer crystal tube (8) and the inner crystal tube (9) through the conveying pipe (16). After absorbing heat, it vaporizes and flows out from the refrigerant outlet pipe (15) located between the outer crystal tube (8) and the inner crystal tube (9). Seawater enters from the water inlet pipe (17) at the lower end of the shell (7), and exchanges heat with the refrigerant and freezes on the inner side of the inner crystal tube (9) and the outer side of the outer crystal tube (8), respectively. The rotating shaft (3) drives the inner scraper and the outer scraper (12) fixed on the scraper holder (13) to peel off the ice crystals on the inner side of the inner crystal tube (9) and the outer side of the outer crystal tube (8), respectively. The obtained ice crystals flow out from the first outlet ice water pipe (18) at the upper end of the side of the inner crystal tube (9) and the second outlet ice water pipe (19) at the upper end of the side of the shell (7), respectively.

Claims

1. A small-scale frozen seawater desalination crystallizer, comprising an upper end bearing (1), an upper end cap (2), a rotating shaft (3), a lower end cap (4), a lower end bearing (5), a fixed tube sheet (6), a shell (7), an outer crystallization tube (8), an inner crystallization tube (9), an annular plate (10), an inner scraper (11), an outer scraper (12), a scraper holder (13), a refrigerant inlet pipe (14), a refrigerant outlet pipe (15), a conveying pipe (16), a water inlet pipe (17), a first outlet chilled water pipe (18), a second outlet chilled water pipe (19), and a variable frequency motor (20); the inner crystallization tube (9) passes through and is fixed on the fixed tube sheet (6), the top end of which is fixed to the upper end cap (2) by screws, and the upper side end is provided with the first outlet chilled water pipe (18); the outer... The outer crystal tube (8) is sleeved on the outside of the inner crystal tube (9) and fixed on the fixed tube plate (6); the lower end of the outer crystal tube (8) and the lower end of the inner crystal tube (9) are sealed by welding through an annular plate (10); the fixed tube plate (6) is provided with a refrigerant inlet pipe (14) and a refrigerant outlet pipe (15) located between the outer crystal tube (8) and the inner crystal tube (9); the conveying pipe (16) is connected to the refrigerant inlet pipe (14), and there are 12 of them, which are evenly distributed between the outer crystal tube (8) and the inner crystal tube (9); the fixed tube plate (6) and the lower end cap (4) are fixed on the shell (7) by screws; the lower end of the shell (7) is provided with a water inlet pipe (17), and the upper side is provided with a second outlet chilled water pipe (19).

2. A small-scale frozen seawater desalination crystallizer according to claim 1, characterized in that, The rotating shaft (3) is located in the inner crystallization tube (9) and is fixed by the upper bearing (1) of the upper end cap (2) and the lower bearing (5) of the lower end cap (4); the inner scraper (11) is fixed on the rotating shaft (3) to peel off the ice crystals inside the inner crystallization tube (9), and the number is 4; the knife holder (13) is fixed on the rotating shaft (3) located at the lower end of the inner scraper (11); the outer scraper (12) is fixed on the knife holder (13) to peel off the ice crystals outside the outer crystallization tube (8), and the number is 4; the variable frequency motor (20) rotates the inner scraper (11) and the outer scraper (12) on the knife holder (13) through the rotating shaft (3).

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