CN108591992B - A scale-free steam generator - Google Patents

Abstract

The invention discloses a scale-free steam generator, which comprises a water supply module, an evaporation cavity, a heating module, an exhaust module, a liquid discharge module and a liquid distribution module, wherein the liquid distribution module is arranged in the evaporation cavity and comprises: the liquid distribution groove is positioned below the water supply port of the water supply module; the two ends of the evaporation surface are provided with height differences, the edge of the upper end is in butt joint with at least part of the edge of the liquid distribution groove, and the edge of the lower end is communicated with the water inlet of the liquid discharge module; the edges of the liquid distribution groove, which are in butt joint with the evaporation surface, are horizontally arranged; the scale-free steam generator adopts a gas-liquid separation method to discharge high-concentration waste liquid, avoids accumulation of scale in the device, forms a uniform liquid film on the evaporation surface, greatly improves the evaporation efficiency, and has the advantages of low cost, compact structure, strong practicability, long service life and the like.

Description

A scale-free steam generator

Technical Field

The invention relates to the technical field of steam generators, and in particular to a scale-free steam generator.

Background technique

Steam generators generate steam by heating water supply and are widely used in catering, medical, cleaning and other industries. However, most steam generators on the market will form scale on the evaporation surface or in the pipeline after a period of use, which greatly reduces the heating efficiency of the steam generator and even blocks the pipeline. The scale problem seriously limits the service life of the steam generator.

The current common method to solve the scale problem is to use chemical descaling agents such as acetic acid for regular cleaning, or add softeners to the water. This method is usually used in industrial boilers, but not in food-grade steam generators in the catering and medical industries. The second method is to use distilled water or purified water as the water supply, which can significantly prevent the accumulation of scale, but this method increases the cost of use and also limits the expansion of steam generators into the household market.

In recent years, some people have proposed some scale-free steam generator structures suitable for food processing. For example, the patent document with publication number CN105864738A discloses a scale-free steam generator, which includes a heating body and a water storage chamber arranged therein. The bottom of the water storage chamber is inclined and has a water outlet arranged downwardly. The bottom of the water storage chamber is connected to the side wall of the water storage chamber by a large arc transition surface. The water storage chamber of the above device is cylindrical, and the inner surface is smooth without corners, so scale cannot accumulate; when the water is discharged at a large R angle and a large slope at the bottom of the water storage chamber, the downward impact of water is very large, and the scale is flushed into the water receiving tank through the drain pipe; the water inlet pipe and the steam generator have a downward inclination angle, which is conducive to the discharge of water scale.

However, the above-mentioned steam generator has the problems of high processing cost, compact structure, large heat loss, low thermal efficiency, etc.

Summary of the invention

The invention provides a scale-free steam generator, which has the advantages of high thermal efficiency, compact structure, low cost and long maintenance period.

A scale-free steam generator comprises a water supply module, an evaporation chamber, a heating module, an exhaust module and a liquid discharge module, and also comprises a liquid distribution module installed in the evaporation chamber, the liquid distribution module comprising:

A liquid distribution tank, located below the water supply port of the water supply module;

The evaporation surface has a height difference at both ends, the edge of the upper end is connected to at least part of the edge of the liquid distribution groove, and the edge of the lower end is connected to the water inlet of the drainage module; the edge of the liquid distribution groove connected to the evaporation surface is set horizontally.

The present invention can further reduce the water supply flow rate by setting the liquid distribution groove, realize sufficient liquid separation in the depth direction, and the overflowed water forms a uniform liquid film on the evaporation surface. In addition, the bottom end of the evaporation surface is connected with the water inlet of the drainage module to realize rapid drainage and avoid scale formation.

The liquid distribution groove may be in various shapes such as round, strip, curved, etc. In order to improve efficiency and facilitate manufacturing, preferably, the liquid distribution groove is a strip groove, and the edges of the two long sides are respectively connected to the evaporation surface inclined outward.

In order to improve space utilization and generation efficiency, preferably, the inclination angle of the evaporation surface is 50° to 85°.

Preferably, the roughness of the evaporation surface is Ra0.5 to Ra15. The evaporation surface is roughened to increase the vaporization core and improve the evaporation efficiency.

Preferably, the evaporation surface is provided with a plurality of buffer sections in the height direction, and the water is re-distributed after being decelerated through the buffer sections, so as to increase the contact time between the water and the evaporation surface.

In order to replenish the water flow evenly, preferably, the water supply module includes a water supply chamber connected to the water supply pipeline and installed in the evaporation chamber, the water supply chamber is located above the liquid distribution tank, and the bottom of the water supply chamber is provided with a water supply slit extending along the length direction of the liquid distribution tank. The above structure can increase the water in the liquid distribution tank evenly and in small amounts, further improving the uniformity of the water film on the evaporation surface.

The shape of the water supply chamber can be adjusted as needed. To facilitate manufacturing and installation, preferably, the water supply chamber is an extension of the water supply pipeline in the evaporation chamber.

The heating module can be installed in many ways as long as it can heat the evaporation surface. In order to improve the generation efficiency, preferably, the heating body of the heating module is arranged between the two evaporation surfaces, and a heat-conducting medium is filled between the heating body and the back of the evaporation surface.

In order to improve the generation efficiency and ensure full utilization of energy, preferably, a temperature sensing element is installed between the two evaporation surfaces to monitor the internal temperature of the steam generator. When the temperature is high, it means that all the feed water in the evaporation chamber has evaporated, then the water pump is controlled to increase the feed water flow rate or reduce the heating power of the heating body; when the temperature is too high to be controlled, the power supply of the heating body is cut off to prevent accidents.

In order to improve the steam quality, preferably, the exhaust module comprises:

a saturated steam pipeline, connected to the steam outlet of the evaporation chamber;

A superheated steam pipeline, wherein the pipeline is installed in the evaporation chamber near the heating body, with both ends extending out of the evaporation chamber, and one end of which is connected to the saturated steam pipeline;

The air supply pipeline is connected to the other end of the superheated steam pipeline.

In order to ensure that the water film has sufficient residence time on the evaporation surface, preferably, a drainage slit is formed between the edge of the lower end of the evaporation surface and the inner wall of the evaporation chamber. The drainage slit can slow down the flow rate.

In order to improve the utilization rate of energy, preferably, the water supply module includes a preheating section for exchanging heat with the water receiving box of the drainage module.

The liquid distribution modules can be arranged in series in multiple parallel configurations, which is suitable for steam generators with higher heating temperatures. They can also be used under conditions of smaller heights and larger lengths and widths, making full use of space while increasing the heat exchange contact surface, which is conducive to uniform film formation of water on the evaporation surface.

Beneficial effects of the present invention:

The scale-free steam generator of the present invention adopts a gas-liquid separation method to discharge high-concentration waste liquid, avoiding the accumulation of scale in the device, forming a uniform liquid film on the evaporation surface, greatly improving the evaporation efficiency, and has the advantages of low cost, compact structure, strong practicality, and long service life.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a scale-free steam generator according to Example 1.

FIG. 2 is a schematic cross-sectional view of the scale-free steam generator of Example 1. FIG.

FIG3 is a schematic cross-sectional view of the scale-free steam generator of Example 2. FIG.

FIG. 4 is a schematic cross-sectional view of a scale-free steam generator of Example 3. FIG.

Explanation of the reference numerals: 1. water supply pipeline, 2. liquid inlet slit, 3. evaporation chamber, 4. liquid distribution trough, 5. evaporation surface, 6. heating body, 7. saturated steam pipeline, 8. superheated steam pipeline, 9. liquid discharge slit, 10. water collecting box, 11. temperature sensing element, 12. evaporator casing, 13. air supply pipeline.

Detailed ways

Example 1

As shown in Figures 1 and 2, the scale-free steam generator of this embodiment includes: a water supply pipeline 1, a liquid inlet slit 2, an evaporation chamber 3, a liquid distribution tank 4, an evaporation surface 5, a heating body 6, a saturated steam pipeline 7, a superheated steam pipeline 8, a drainage slit 9, a water receiving box 10, a temperature sensing element 11, an evaporator housing 12 and an air supply pipeline 13.

In the embodiment, the liquid inlet slit 2 is a slit arranged on the water supply pipeline 1 from wide to narrow, which reduces the water supply flow rate and appropriately separates the liquid in the depth direction. The width of the slit is determined by the water supply flow rate.

In this embodiment, the evaporation surface 5 is a mountain-shaped slope, which achieves uniform film-forming heating of water.

In this embodiment, the heating body 6 is a heating rod with an aluminum shell, which is bent and placed inside the evaporation surface 5. The superheated steam pipeline 8 is located below the heating body 6 to fully utilize the space and evenly heat.

In this embodiment, the evaporation surface 5 and the liquid distribution tank 4 are aluminum castings, and the interior is reserved for the installation space of the heating body 6 and the superheated steam pipeline 8. The evaporation surface 5 is roughened to increase the vaporization core and improve the evaporation efficiency.

In this embodiment, a temperature sensing element 11 is also installed inside the evaporation surface 5 to monitor the internal temperature of the steam generator. When the temperature is high, it means that all the feed water in the evaporation chamber has evaporated, so the water pump is controlled to increase the feed water flow rate or reduce the heating power of the heating body accordingly; when the temperature is too high to be controlled, the power supply of the heating body is cut off to prevent accidents.

Its working principle is that the feed water from the water supply pipeline 1 enters the evaporator shell 12 through the water inlet, is buffered and separated by the liquid inlet slit 2, and then flows into the liquid distribution tank 4. In the liquid distribution tank 4, the feed water is preliminarily heated, and then flows into the evaporation surface 5 after being evenly distributed in the depth direction, and forms a uniform liquid film on the evaporation surface to perform falling film evaporation.

After evaporation, part of the feed water enters the evaporation chamber 3 in the form of saturated steam, and part of the feed water flows down the heating surface 5 but still does not evaporate, and then flows out of the evaporation chamber 3 through the drainage slit 9 as waste liquid, passes through the water receiving box 10 and flushes away the scale. The water receiving box 10 is made of insulating material and needs to be cleaned regularly to remove the accumulated liquid and scale.

Under the action of pressure difference, the saturated steam in the evaporation chamber 3 enters the superheated steam pipeline 8 inside the evaporation surface 5 through the exhaust port and the saturated steam pipeline 7 to be further heated, and finally forms superheated steam to enter the steam supply pipeline 13.

Example 2

As shown in Figure 3, the scale-free steam generator of this embodiment includes: a water supply pipeline 1, a liquid inlet slit 2, an evaporation chamber 3, a liquid distribution tank 4, an evaporation surface 5, a heating body 6, a saturated steam pipeline 7, a superheated steam pipeline 8, a drainage slit 9, a water receiving box 10, a temperature sensing element 11, an evaporator shell 12 and an air supply pipeline 13.

In the embodiment, the liquid inlet slit 2 is a slit arranged on the water supply pipeline 1 from wide to narrow, which reduces the water supply flow rate and appropriately separates the liquid in the depth direction. The width of the slit is determined by the water supply flow rate.

In this embodiment, the evaporation surface 5 is provided with a plurality of buffer sections in the height direction on the basis of the peak-shaped slope. After the water flows through the buffer section and slows down, the water is redistributed to increase the contact time between the water and the evaporation surface 5 .

In this embodiment, the heating body 6 is a heating rod with an aluminum shell, which is bent and placed inside the evaporation surface 5. The superheated steam pipeline 8 is located below the heating body 6 to fully utilize the space and evenly heat.

In this embodiment, the evaporation surface 5 and the liquid distribution tank 4 are aluminum castings, and the interior is reserved for the installation space of the heating body 6 and the superheated steam pipeline 8. The evaporation surface 5 is roughened to increase the vaporization core and improve the evaporation efficiency.

In this embodiment, a temperature sensing element 11 is also installed inside the evaporation surface 5 to monitor the internal temperature of the steam generator. When the temperature is high, it means that all the feed water in the evaporation chamber has evaporated, so the water pump is controlled to increase the feed water flow rate or reduce the heating power of the heating body accordingly; when the temperature is too high to be controlled, the power supply of the heating body is cut off to prevent accidents.

Its working principle is that the feed water from the water supply pipeline 1 enters the evaporator shell 12 through the water inlet, is buffered and separated by the liquid inlet slit 2, and then flows into the liquid distribution tank 4. In the liquid distribution tank 4, the feed water is preliminarily heated, and then flows into the evaporation surface 5 after being evenly distributed in the depth direction, and forms a uniform liquid film on the evaporation surface to perform falling film evaporation.

After evaporation, part of the feed water enters the evaporation chamber 3 in the form of saturated steam, and part of the feed water flows down the heating surface 5 but still does not evaporate, and then flows out of the evaporation chamber 3 through the drainage slit 9 as waste liquid, passes through the water receiving box 10 and flushes away the scale. The water receiving box 10 is made of insulating material and needs to be cleaned regularly to remove the accumulated liquid and scale.

Under the action of pressure difference, the saturated steam in the evaporation chamber 3 enters the superheated steam pipeline 8 inside the evaporation surface 5 through the exhaust port and the saturated steam pipeline 7 to be further heated, and finally forms superheated steam to enter the steam supply pipeline 13.

Example 3

As shown in Figure 4, the scale-free steam generator of this embodiment includes: a water supply pipeline 1, a liquid inlet slit 2, an evaporation chamber 3, a liquid distribution tank 4, an evaporation surface 5, a heating body 6, a saturated steam pipeline 7, a superheated steam pipeline 8, a drainage slit 9, a water receiving box 10, a temperature sensing element 11, an evaporator housing 12, and an air supply pipeline 13.

In the embodiment, the liquid inlet slit 2 is a slit arranged on the water supply pipeline 1 from wide to narrow, which reduces the water supply flow rate and appropriately separates the liquid in the depth direction. The width of the slit is determined by the water supply flow rate.

In this embodiment, the evaporation surface 5 is in the form of multiple mountain-shaped slopes connected in series, which is suitable for steam generators with higher heating temperatures. It can also be used under conditions of smaller height and larger length and width, making full use of space and increasing the heat exchange contact surface, which is conducive to uniform film formation of water on the evaporation surface.

In this embodiment, the heating body 6 is a heating rod with an aluminum shell, which is bent and placed inside the evaporation surface 5. The superheated steam pipeline 8 is located below the heating body 6 to fully utilize the space and evenly heat.

In this embodiment, the evaporation surface 5 and the liquid distribution tank 4 are aluminum castings, and the interior is reserved for the installation space of the heating body 6 and the superheated steam pipeline 8. The evaporation surface 5 is roughened to increase the vaporization core and improve the evaporation efficiency.

In this embodiment, a temperature sensing element 11 is also installed inside the evaporation surface 5 to monitor the internal temperature of the steam generator. When the temperature is high, it means that all the feed water in the evaporation chamber has evaporated, so the water pump is controlled to increase the feed water flow rate or reduce the heating power of the heating body accordingly; when the temperature is too high to be controlled, the power supply of the heating body is cut off to prevent accidents.

Its working principle is that the feed water from the water supply pipeline 1 enters the evaporator shell 12 through the water inlet, is buffered and separated by the liquid inlet slit 2, and then flows into the liquid distribution tank 4. In the liquid distribution tank 4, the feed water is preliminarily heated, and then flows into the evaporation surface 5 after being evenly distributed in the depth direction, and forms a uniform liquid film on the evaporation surface to perform falling film evaporation.

After evaporation, part of the feed water enters the evaporation chamber 3 in the form of saturated steam, and part of the feed water flows down the heating surface 5 but still does not evaporate, and then flows out of the evaporation chamber 3 through the drainage slit 9 as waste liquid, passes through the water receiving box 10 and flushes away the scale. The water receiving box 10 is made of insulating material and needs to be cleaned regularly to remove the accumulated liquid and scale.

Under the action of pressure difference, the saturated steam in the evaporation chamber 3 enters the superheated steam pipeline 8 inside the evaporation surface 5 through the exhaust port and the saturated steam pipeline 7 to be further heated, and finally forms superheated steam to enter the steam supply pipeline 13.

To sum up, the scale-free steam generator of this embodiment discharges high-concentration waste liquid, avoids the accumulation of scale in the device, forms a uniform liquid film on its evaporation surface, and greatly improves the evaporation efficiency; it also has the advantages of low cost, compact structure, high safety, strong practicality, and long service life.

Claims (6)

1. A scale-free steam generator, comprising a water supply module, an evaporation chamber, a heating module, an exhaust module and a liquid discharge module, characterized in that it also comprises a liquid distribution module installed in the evaporation chamber, the liquid distribution module comprising: A liquid distribution tank, located below the water supply port of the water supply module; The evaporation surface has a height difference at both ends, the edge of the upper end is butted against at least part of the edge of the liquid distribution groove, and the edge of the lower end is connected to the water inlet of the drainage module; the edge of the liquid distribution groove butted against the evaporation surface is arranged horizontally; The liquid distribution groove is a strip-shaped groove, and the edges of the two long sides are respectively connected to the evaporation surface inclined outward; The inclination angle of the evaporation surface is 50° to 85°; The heating body of the heating module is arranged between the two evaporation surfaces, and a heat-conducting medium is filled between the heating body and the back of the evaporation surface; The exhaust module comprises: a saturated steam pipeline, connected to the steam outlet of the evaporation chamber; A superheated steam pipeline, wherein the pipeline is installed in the evaporation chamber near the heating body, with both ends extending out of the evaporation chamber, and one end of which is connected to the saturated steam pipeline; The air supply pipeline is connected to the other end of the superheated steam pipeline. 2. The scale-free steam generator according to claim 1 is characterized in that the water supply module includes a water supply chamber connected to the water supply pipeline and installed in the evaporation chamber, the water supply chamber is located above the liquid distribution trough, and a water supply slit extending along the length direction of the liquid distribution trough is provided at the bottom of the water supply chamber. 3. The scale-free steam generator according to claim 2, characterized in that the water supply chamber is an extension of the water supply pipeline in the evaporation chamber. 4. The scale-free steam generator according to claim 1, characterized in that a temperature sensing element is installed between the two evaporation surfaces. 5. The scale-free steam generator according to claim 1, characterized in that a liquid drainage slit is formed between the edge of the lower end of the evaporation surface and the inner wall of the evaporation chamber. 6. The scale-free steam generator according to claim 1, characterized in that the water supply module includes a preheating section for exchanging heat with a water receiving box of the drainage module.