A shell and tube heat exchanger for preventing algae and scaling

Abstract

The present invention discloses a shell and tube heat exchanger for preventing algae and scaling. Several groups of baffles are arranged in the shell, and each group of baffles includes small baffles and large baffles arranged in sequence; a spacing tube is also arranged in the shell, and the spacing tube passes through the large baffle and the small baffle in sequence; the large baffle is annular, and the outer diameter of the large baffle is equal to the diameter of the shell; the small baffle is circular; and several guide plates are also arranged in each group of baffles, and the guide plates are vertically fixed on the side of the large baffle facing the water outlet, and the guide plates are arc-shaped. The device of the present invention enables the water in the shell and tube heat exchanger to continuously change the direction of the water flow, and at the same time form turbulence, and the water flow has a strong scouring force, so that the scouring effect of water on the inner surface of the shell and the outer surface of the heat exchange tube is significantly increased, and the algae plants are prevented from growing and scaling on the inner surface of the shell side of the heat exchanger and the outer surface of the heat exchange tube, so that the shell side of the heat exchanger has a significant effect of preventing algae and scaling.

Description

Technical Field

[0001] The invention relates to the technical field of shell and tube heat exchangers, and in particular to a shell and tube heat exchanger for preventing algae and scaling. Background Art

[0002] Shell and tube heat exchangers are popular in the chemical, pharmaceutical, food and other industries due to their simple and compact structure and low cost. The tube side of the shell and tube heat exchanger is easy to clean. Even if the tube side is blocked, it is easy to mechanically clean it by disassembling the shells at both ends. However, the shell side of the shell and tube heat exchanger cannot be disassembled for mechanical cleaning. Before the water in the circulating water pool enters the shell side, there are often a large number of active microorganisms (such as algae) and suspended matter, which can easily cause a large number of active microorganisms to adhere to the inner surface of the shell on the shell side and the outer surface of the heat exchange tube. Once these active microorganisms are attached in large numbers in the shell side, they will rapidly reproduce and grow under suitable temperature and environment conditions, which can easily cause the shell side to be blocked, affecting the efficiency of heat exchange, and even causing the heat exchanger to lose its heat exchange effect. In addition, since the water in the circulating water pool contains a large amount of Ca 2+ Mg 2+ Isocations and CO3 2- 、HCO3 - Anions such as ions can easily form scale on the inner wall of the shell and the outer wall of the heat exchange tube when the water flow rate in the shell side is not large, affecting the efficiency of heat exchange.

[0003] The baffles of the traditional structure can only make water flow from the inner wall of the shell to the vicinity of the center in one direction. The water flow in the heat exchanger is short and the flow rate is slow, which makes it easy to form algae and scale on the inner wall of the shell and the outer surface of the heat exchange tube. Therefore, many spiral baffles appeared later. For example, application number 201910498389 discloses a bent 3-point spiral baffle heat exchanger, and application number 201821969180 discloses a silicon carbide shell and tube heat exchanger with high heat exchange efficiency. Spiral baffles are used in heat exchangers, but the manufacturing process of this heat exchanger is complicated and the cost is high; the change of water flow direction is limited and the water flow speed is unchanged, the flushing force is small, and the algae and scale removal effect is not very prominent. Therefore, a shell and tube heat exchanger is needed now. Through the improvement of the baffle, it can not only continuously change the direction of water flow, but also increase the flushing force of water flow, so that water forms turbulence between the inner surface of the shell of the heat exchanger and the outer surface of the heat exchange tube, with significant anti-algae and anti-scale effects, simple production and low cost. Summary of the invention

[0004] The present invention aims at the deficiencies of the prior art and provides a shell-and-tube heat exchanger for preventing algae and scaling. By improving the baffles and introducing the guide plates, the water in the shell-and-tube heat exchanger can form turbulence with strong scouring force, thereby increasing the scouring effect of water on the inner surface of the shell and the outer surface of the heat exchange tube, preventing algae from growing and scaling on the inner surface of the shell side of the heat exchanger and the outer surface of the heat exchange tube, thereby achieving significant algae and scaling prevention effects on the shell side of the heat exchanger.

[0005] The present invention is achieved through the following technical scheme, which provides a shell-and-tube heat exchanger for preventing algae and scaling, the shell-and-tube heat exchanger includes a shell and a heat exchange tube bundle, the heat exchange tube bundle is fixed on the tube sheets at both ends of the shell, and the two ends of the shell are respectively provided with a water inlet and a water outlet; a plurality of groups of baffles are arranged in the shell, and the heat exchange tube bundle passes through each group of baffles horizontally; each group of baffles includes small baffles and large baffles arranged in sequence, and the large baffles are parallel to the small baffles; the cross-section of the large baffle is annular, and the outer diameter of the large baffle is equal to the diameter of the shell; the cross-section of the small baffle is circular, and the circumference of the small baffle is formed by the distance between the inner wall of the shell and the outer diameter of the large baffle. The area of ​​the ring is equal to the area of ​​the inner circle of the large baffle; the large baffle, the small baffle and the center of the shell cross section are located on the same straight line; each group of baffles is also provided with a number of guide plates, the guide plates are vertically fixed on the side of the large baffle facing the water outlet, and the guide plates are arc-shaped; the guide plates pass through the gaps of the heat exchange tube bundle, one end of the guide plates is connected to the inner wall of the shell, and the other end is located on the inner circle of the large baffle; at least three spacing tubes are also provided in the shell, the spacing tubes pass through the large baffle and the small baffle in turn, one end of the spacing tube is fixed on the tube plate close to one end of the shell water outlet, and the other end is fixed on the large baffle close to the shell water inlet.

[0006] Preferably, the spacing between each set of baffles is the same.

[0007] Preferably, the spacing between the large baffles and adjacent small baffles is the same.

[0008] Preferably, three spacing tubes are arranged in the shell, and the distances between the spacing tubes and adjacent spacing tubes are equal. The spacing tubes can not only determine the spacing between the baffles, but also play a role in fixing the baffles.

[0009] Preferably, one end of the distance tube is fixed on a tube plate close to one end of the shell water outlet, and the other end is fixed on a large baffle close to the shell water inlet.

[0010] Preferably, each set of baffles is provided with 4 to 12 guide plates. The number of guide plates can be set according to the diameter of the heat exchanger shell. The larger the diameter of the heat exchanger shell, the more guide plates are set.

[0011] Preferably, the opening direction of the arc of the guide plate is evenly distributed on the large baffle in a clockwise or counterclockwise direction.

[0012] Preferably, the interval between the guide plate and the small baffle is 0 to 100 mm. That is, when the guide plate can be fixed between the large baffle and the small baffle, the distance between the guide plate and the small baffle is 0 mm; when the guide plate is only fixed on one side of the large baffle and there is a gap between the guide plate and the small baffle, the distance between the guide plate and the small baffle is ≤100 mm. A distance of 0 mm is likely to form a heat exchange dead zone behind the small baffle, affecting the heat exchange efficiency; a distance that is too large is not very good for the formation of eddy currents, and also affects the heat exchange efficiency and does not achieve the effect of the present invention, so the most suitable distance is about 50 mm.

[0013] Preferably, the interval between the guide plate and the small baffle is 50 mm.

[0014] Preferably, the distance between the other end of the guide plate and the center of the large baffle is greater than 0 mm and less than or equal to 10 mm. One end of the guide plate is fixed to the inner wall of the shell, and the other end converges to the center of the large baffle, which has a good guide effect. However, if the other end of the guide plate is located at the center of the large baffle, the guide plates are connected together, and a dead angle is easily formed between the guide plates, which affects the effect of preventing algae and scaling.

[0015] The beneficial effects of the present invention are:

[0016] 1. The device of the present invention achieves the anti-algae and anti-scaling effect on the shell side of the heat exchanger by changing the structural shape of the baffle of the heat exchanger. The area of ​​the baffle is divided into several small areas, and the flow direction of the water is changed by a "guide plate" in each small area, so that the flow direction of the water is changed from flowing toward the center to turbulent flow toward the center, then to the periphery, and then to the center, so that the water forms turbulence between the inner surface of the shell side of the heat exchanger and the outer surface of the heat exchange tube. Due to the formation of turbulence, the flow direction of the water changes, the water flow becomes longer, and the flow rate of the water is significantly increased, thereby increasing the scouring force of the water, thereby increasing the scouring effect of the water on the inner surface of the shell and the outer surface of the heat exchange tube, preventing the growth of algae and the formation of scale on the inner surface of the shell side of the heat exchanger and the outer surface of the heat exchange tube, thereby achieving a significant anti-algae and anti-scaling effect on the shell side of the heat exchanger.

[0017] 2. The device of the present invention has a simple structure, and the large and small baffles and guide plates are easy to manufacture and simple to install. Compared with the spiral baffles, the manufacturing cost and installation cost are much lower, and the overall cost of the shell and tube heat exchanger is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2The flow direction of water in the existing heat exchanger shell (the arrow indicates the flow direction of water, note: the heat exchange tube bundle is omitted on the large baffle and the small baffle);

[0020] Figure 3 is the flow direction of water in the shell of the present invention (the dotted line and arrow indicate the flow direction of water, note: the heat exchange tube bundle is omitted on the large baffle);

[0021] Figure 4 This is a schematic diagram of the structure in which the heat exchange tube bundle is omitted inside the shell;

[0022] Figure 5 It is a schematic diagram of the structure of the fixed-distance tube and the large baffle and the small baffle (the heat exchange tube bundle is omitted on the large baffle and the small baffle);

[0023] As shown in the figure:

[0024] 1. Shell, 2. Large baffle, 3. Small baffle, 4. Heat exchange tube bundle, 5. Guide plate, 6. Spacer tube, 7. Tube sheet, 8. Water inlet, 9. Water outlet. DETAILED DESCRIPTION

[0025] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0026] As described in the background art, the baffles in the existing shell-and-tube heat exchangers are generally circular or spiral. By modifying the baffles, the flow rate of water in the shell may change, but the direction of the water flow remains basically unchanged. There are still dead corners in the shell, and the inner wall of the shell and the tube bundle cannot be effectively flushed.

[0027] Based on this, the present invention provides a shell and tube heat exchanger for preventing algae and scaling, such as Figure 1As shown, the shell-and-tube heat exchanger includes a shell 1 and a heat exchange tube bundle 4, the heat exchange tube bundle 4 is fixed on the tube sheets 7 at both ends of the shell 1, and the two ends of the shell 1 are respectively provided with a water inlet 8 and a water outlet 9; a plurality of groups of baffles are arranged in the shell 1, and the heat exchange tube bundle 4 passes through each group of baffles horizontally; each group of baffles includes a small baffle 3 and a large baffle 2 arranged in sequence, and the large baffle 2 is parallel to the small baffle 3; the cross-section of the large baffle 2 is annular, and the outer diameter of the large baffle 2 is equal to the diameter of the shell 1; the cross-section of the small baffle 3 is circular, and the circumference of the small baffle 3 is 1 / 4 of the circle formed by the inner wall of the shell 1 The area is equal to the area of ​​the inner circle of the large baffle 2; the center of the circle of the large baffle 2, the small baffle 3 and the cross section of the shell 1 is located on the same straight line; each group of baffles is also provided with a plurality of guide plates 5, the guide plates 5 are vertically fixed on the side of the large baffle 2 facing the water outlet 9, and the guide plates 5 are arc-shaped; the guide plates 5 pass through the gap of the heat exchange tube bundle 4, one end of the guide plates 5 is connected to the inner wall of the shell 1, and the other end is located on the inner circle of the large baffle 2; at least two spacing tubes 6 are also provided in the shell 1, the spacing tubes 6 pass through the large baffle 2 and the small baffle 3 in turn, and the two ends of the spacing tubes 6 are fixed on the tube sheets 7 at both ends of the shell 1.

[0028] The spacing between each group of baffles is the same. The spacing between the large baffles 2 and the adjacent small baffles 3 is the same.

[0029] Three spacing tubes 6 are arranged in the shell 1. The distances between the spacing tubes 6 and the adjacent spacing tubes 6 are equal. One end of the spacing tube 6 is fixed to the tube sheet 7 at one end of the water outlet 9 of the shell 1, and the other end is fixed to the large baffle 2 near the water inlet 8. There are 4 to 12 guide plates 5 in each group of baffles. The arc-shaped opening direction of the guide plate 5 is evenly distributed on the large baffle 2 in a clockwise / or counterclockwise direction. The interval between the guide plate 5 and the small baffle 3 is 0 to 100 mm. The interval between the guide plate 5 and the small baffle 3 is 50 mm. The distance between the other end of the guide plate 5 and the center of the large baffle 2 is greater than 0 mm and less than or equal to 10 mm.

[0030] The shell and tube heat exchanger of the present invention can change the flow direction of water. The flow direction of water in the shell 1 of the existing shell and tube heat exchanger is as follows: Figure 2As shown, the present invention changes a baffle into a group of baffles, and each group of baffles is provided with a large annular baffle 2 and a small circular baffle 3; because the large baffle 2 and the small baffle 3 are arranged in sequence in the shell 1, the direction of the water flow will change after passing through each baffle, and the shell-and-tube heat exchanger can be flushed without dead ends. At the same time, a guide plate 5 is arranged inside each group of baffles, and the guide plate 5 is vertically fixed on the large baffle 2. After the water flows through the large baffle 2, it enters the space formed between the guide plates 5. Under the action of the arc-shaped guide plate 5, the direction of the water flow changes from flowing toward the center to flowing toward the center and then swirling toward the inner wall of the shell 1 (such as Figure 3 As shown), water forms turbulence between the inner surface of the heat exchanger shell and the outer surface of the heat exchange tube. Due to the formation of turbulence, the flow direction of water changes, the water flow becomes longer, the water flow rate is significantly increased, and the scouring force of water is increased, thereby increasing the scouring effect of water on the inner surface of the shell and the outer surface of the heat exchange tube, preventing the growth and scaling of algae plants on the inner surface of the shell side of the heat exchanger and the outer surface of the heat exchange tube, so that the shell of the heat exchanger can achieve the anti-algae and anti-scaling effect. Since the area of ​​the ring formed between the circumference of the small baffle 3 and the inner wall of the shell 1 is equal to the area of ​​the inner circle of the large baffle 2, through such a setting, the flow rate of water passing through the large baffle 2 and the small baffle 3 each time remains unchanged and the direction is constantly changing. The setting of the guide plate 5 increases the flow rate of water, which is equivalent to accelerating the water flow each time it passes through the guide plate 5, increasing the scouring force of the water flow, and virtually forming multiple water flow accelerators. Not only does it ensure that the water flow has no dead corners, but it also increases the flushing force, effectively preventing algae and scaling.

[0031] Example

[0032] A shell-and-tube heat exchanger for preventing algae and scaling, the shell-and-tube heat exchanger is a horizontal shell-and-tube heat exchanger, comprising a shell 1 and a heat exchange tube bundle 4, the heat exchange tube bundle 4 is fixed on the tube sheets 7 at both ends of the shell 1, and the two ends of the shell 1 are respectively provided with a water inlet 8 and a water outlet 9; a plurality of groups of baffles are arranged in the shell 1, and the heat exchange tube bundle 4 passes through each group of baffles horizontally; each group of baffles comprises a small baffle 3 and a large baffle 2 arranged in sequence, and the large baffle 2 is parallel to the small baffle; the spacing between each group of baffles is the same. The spacing between the large baffle 2 and the adjacent small baffles 3 is the same. The cross section of the large baffle 2 is annular, and the outer diameter of the large baffle 2 is equal to the diameter of the shell 1; the cross section of the small baffle 3 is circular, and the area of ​​the ring formed between the circumference of the small baffle 3 and the inner wall of the shell 1 is equal to the area of ​​the inner circle of the large baffle 2. The center of the cross section of the large baffle 2, the small baffle 3 and the shell 1 is located on the same straight line.

[0033] Four guide plates 5 are provided in each baffle group. The guide plates 5 are vertically fixed on the side of the large baffle 2 facing the water outlet 9, and are arc-shaped; the guide plates 5 pass through the gap of the heat exchange tube bundle 4, one end of the guide plate 5 is connected to the inner wall of the shell 1, and the other end is located on the inner circle of the large baffle 2, and the distance from the center of the large baffle 2 is 5mm; the opening direction of the arc of the guide plate 5 is evenly distributed on the large baffle 2 in a counterclockwise direction. The interval between the guide plate 5 and the small baffle 3 is 50mm.

[0034] Three spacing tubes 6 are provided in the shell 1, and the distances between the spacing tubes 6 and adjacent spacing tubes 6 are equal. The spacing tubes 6 pass through the large baffle 2 and the small baffle 3 in sequence. One end of the spacing tube 6 is fixed on the tube sheet 7 at one end of the water outlet 9 of the shell 1, and the other end is fixed on the large baffle 2 close to the water inlet 8.

[0035] Of course, the above description is not limited to the above examples. Technical features not described in the present invention can be achieved by or by using existing technologies, which will not be described here. The above embodiments and drawings are only used to illustrate the technical scheme of the present invention and are not limitations of the present invention. The present invention is described in detail with reference to the preferred implementation methods. Ordinary technicians in this field should understand that changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention do not depart from the purpose of the present invention, and should also fall within the scope of protection of the claims of the present invention.

Claims

1. A shell and tube heat exchanger for preventing algae and scaling, the shell and tube heat exchanger comprising a shell and a heat exchange tube bundle, the heat exchange tube bundle is fixed on the tube sheets at both ends of the shell, and the two ends of the shell are respectively provided with a water inlet and a water outlet; characterized in that: The shell is provided with a plurality of groups of baffles, and the heat exchange tube bundle passes through each group of baffles horizontally; each group of baffles includes a small baffle and a large baffle arranged in sequence, and the large baffle is parallel to the small baffle; the cross section of the large baffle is annular, and the outer diameter of the large baffle is equal to the diameter of the shell; the cross section of the small baffle is circular, and the area of ​​the ring formed between the circumference of the small baffle and the inner wall of the shell is equal to the area of ​​the inner circle of the large baffle; the large baffle, the small baffle and the center of the shell cross section are located on the same straight line; each group of baffles is also provided with a plurality of guide plates, and the guide plates are vertically fixed on the side of the large baffle facing the water outlet, and the guide plates are arc-shaped; The plate passes through the gap of the heat exchange tube bundle, one end of the guide plate is connected to the inner wall of the shell, and the other end is located on the inner circle of the large baffle; at least three spacing tubes are also arranged in the shell, and the spacing tubes pass through the large baffle and the small baffle in sequence, one end of the spacing tube is fixed on the tube plate close to one end of the shell water outlet, and the other end is fixed on the large baffle close to the shell water inlet; the spacing between each group of baffles is the same; the opening direction of the arc of the guide plate is evenly distributed on the large baffle in a clockwise or counterclockwise direction; the interval between the guide plate and the small baffle is 0~100mm; the distance between the other end of the guide plate and the center of the large baffle is greater than 0mm and less than or equal to 10mm.

2. The shell and tube heat exchanger according to claim 1, characterized in that: The distances between the large baffles and the adjacent small baffles are the same.

3. The shell and tube heat exchanger according to claim 1, characterized in that: Three distance tubes are arranged in the shell, and the distances between the distance tubes and adjacent distance tubes are equal.

4. The shell and tube heat exchanger according to claim 3, characterized in that: One end of the distance pipe is fixed on a tube plate close to one end of the water outlet of the shell, and the other end is fixed on a large baffle close to the water inlet of the shell.

5. The shell and tube heat exchanger according to claim 1, characterized in that: Each set of baffles is equipped with 4 to 12 guide plates.

6. The shell and tube heat exchanger according to claim 1, characterized in that: The interval between the guide plate and the small baffle is 50 mm.

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