RU2493484C2 - Steam generator - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: boiler is equipped with flexible electric heaters of cable or tape type and a reflecting screen, and its outer surface is made with grooves arranged along a helical line, where flexible electric heaters are laid, at the same time grooves for the cable type of electric heaters are made in the form of a semicircumference, and for the tape type they are "П"-shaped.

EFFECT: increased service life of a steam generator, higher efficiency of steam generation and reduction of costs for maintenance and repair of a steam generator.

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Description

The invention relates to steam generators designed to generate process steam of low and medium pressures of low productivity, which are in demand in enterprises of light, food and other industries.

Known steam generator [1], containing a boiler, inside of which are installed electric heaters in the form of tubular heating elements.

In addition, a steam generator [2] is known that contains a boiler, inside of which three electrodes are installed as electric heaters.

The main disadvantage of the above steam generators is that when steam is formed on the surface of the electric heaters, scale is formed, which reduces the efficiency of steam generation and their service life, and also increases the cost of their maintenance.

The present invention is directed to solving the technical problem of eliminating these disadvantages:

- increasing the efficiency of vaporization;

- increase the life of the steam generator;

- reducing the cost of maintenance and repair of the steam generator.

The technical result, which consists in eliminating these shortcomings in a steam generator containing a boiler with inlet and outlet pipes, inside which electric heaters are installed in the form of tubular electric heaters or electrodes and water level control sensors, is achieved due to the fact that the boiler is equipped with flexible electric heaters: cable or tape type and a reflective screen, and its outer surface is made with grooves located along a helical line into which flexible electric heaters fit, while the grooves for the cable type of electric heaters are made in the form of a semicircle, and for the tape type U-shaped.

The invention is illustrated by drawings, where figure 1 schematically shows a General view of a steam generator; figure 2 shows the design of the boiler with flexible electric heaters: (a) - cable type, (b) - tape type.

The steam generator contains a boiler 1, on the outer surface of which in the grooves located along the helical line, flexible electric heaters 2 are installed, which are externally fenced by a reflective screen 3. On the lid of the boiler 1, water level sensors in the boiler are fixed:

D ₁ - upper level control sensor;

D ₂ - sensor control the lower level;

D ₃ - sensor for monitoring the lack of water in the boiler 1.

In addition, the boiler 1 has pipelines water 4 and steam 5.

A drain valve 6, a non-return valve 7, an electric pump 8 and an electrovalve 9 are installed on the water pipeline 4.

An exhaust valve for steam 10, a pressure gauge 11, a pressure switch 12 and a pressure relief valve 13 are installed on the steam pipeline 5.

The steam generator operates as follows.

When the steam generator is turned on in the three-phase current network, voltage is supplied to the control circuits and power circuits, as indicated by the light bulb.

In the absence of water in the boiler 1 or its insufficient level, which is signaled by the control sensors D ₃ and D ₂ , voltage is applied to the solenoid valve 9 and electric pump 8 (Fig. 1)

In this case, through the water pipe 4 and the check valve 7, the boiler 1 is filled with water.

Upon reaching the water level to the sensor D ₂ is the inclusion of electric heaters 2.

When the water level reaches the sensor D ₁ , the solenoid valve 9 and the electric pump 8 are turned off. The filling of the boiler 1 with water stops. The process of vaporization takes place. Steam from the boiler is discharged through the exhaust valve 10.

When the water level drops to the sensor D ₂ , the electrovalve 9 and the electric pump 8 are turned on again.

When the water level in the boiler 1 drops to the sensor D ₃ , the electric heaters 2 are turned off and an audible alarm sounds when there is no water in the boiler 1.

The pressure in the boiler 1 is regulated using the pressure switch sensor 12.

If the steam pressure in the boiler 1 rises above a predetermined one, the pressure switch 12 disconnects the electric heaters 2 from the electric network and the vaporization stops.

In order to increase the use of efficiency of flexible electric heaters 2, on the one hand, grooves are made along the outer surface of the boiler 1, in which flexible electric heaters 2 are laid in a spiral, and on the other hand, a reflective screen 3 is installed (Fig. 2). In this case, the grooves are made for electric heaters of cable type (figa) in the form of a semicircle, and for the tape type (fig.2b) of a U-shaped.

The steam generator circuit provides:

- the release of steam through the safety valve 13 in the event of failure of the sensor pressure switch 12;

- visual control of the vapor pressure in the boiler 1 by means of a pressure gauge 11.

Information sources

1. Copyright certificate SFI 1638444 A1, F22B, 1/28 published March 30, 1991

2. Patent RU 2315232 C2, F22B 1/30, published January 20, 2008.

Claims (1)

A steam generator, consisting of a boiler with an inlet and outlet pipe, inside which electric heaters are installed in the form of electric heating elements or electrodes and water level control sensors in the boiler, characterized in that the boiler is equipped with flexible cable or ribbon type electric heaters, and its outer surface is made with grooves located along a helical line into which flexible electric heaters fit, while the grooves for the cable type of electric heaters are made in the form of a semicircle, and for tape type - U-shaped.

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