ITPD20010028A1 - STEAM GENERATOR WITH AUTOMATIC WATER FILLING SYSTEM. - Google Patents

Description

TITLE

NEW STEAM GENERATOR WITH SYSTEM OF

AUTOMATIC WATER LOADING

DESCRIPTION

The present invention relates to steam generation boilers with an automatic water loading system. The innovation finds particular, if not exclusive application, in the sector of equipment that uses steam to carry out their domestic or industrial functions such as ironing systems, cleaning machines, pressure washers, hydrojet extraction systems, combined vacuum cleaners, etc.

One of the efficiency parameters of steam generators is the ability to guarantee a constant quantity of steam for as long as possible. Many continuous steam generators consist of an electrically heated vaporization chamber supplied with cold water from a separate tank.

The efficiency of the steam production system also depends on the ability of the charging system to keep the pressure level in the vaporization chamber as constant as possible.

The various known mechanisms for controlling the water level in the vaporization chamber are affected by various mechanical, electrical, limescale deposit, overheating and cooling problems. Patent application PD2000A000279 owned by the same applicants of this patent describes a steam generator having a lower portion of the top of the vaporization chamber and located at the substantially lower level of the water to be vaporized. A small resistance and a thermostat inserted in the lower part of the top of the vaporization chamber act as a low water level detector: when the water is consumed and does not touch the lower part of the top, the electrical resistance overheats this part of the vaporization chamber. , the thermostat detects this overheating and controls the operation of the pump for filling the vaporization chamber with cold water from the tank; the top-up water touches the lower part of the vaporization chamber ceiling, cooling it and causing the intervention of the thermostat that blocks the pump.

This steam generator has the drawbacks of being linked to the material of the tank and to the two-level top shape of the vaporization chamber.

To obviate all the aforesaid drawbacks, a new type of steam generator has been studied and implemented with a vaporization chamber of any material and shape and with a new extremely sensitive probe.

The new steam generator consists in its main parts of a vaporization chamber with main electric heating resistance, a new water level probe, a tank for cold water topping up, a pump and parts accessory such as pressure switches, solenoid valves, and the like.

In particular, the vaporization chamber has any shape, for example regular, parallelepiped, cylindrical or that required and necessary for the appliance that uses the steam.

On one side of the vaporization chamber there is a hole or through housing that allows the insertion and fixing of the new water level probe.

The filling duct or hole of the vaporization chamber is located on the top of the chamber itself, near or vertically of the probe so that the filling water invests or otherwise affects the probe itself as quickly as possible.

The new probe consists of a generally parallelepiped or cylindrical heat conducting body with an end flange for its attachment to the vaporization chamber wall.

Inside the probe body there is an electrical resistance thermometer while a thermostat is fixed on the flange of the body itself, or in another suitable position.

The probe thus constituted, once inserted, applied and fixed on the wall of the vaporization chamber, is located inside said vaporization chamber. Basically, the lower edge of the probe will identify the minimum water level in which it is necessary to fill the vaporization chamber, while the upper edge of the probe will identify the maximum level, at which the filling of the vaporization chamber is interrupted.

The thermostat of the probe is electrically connected to the filling pump of the vaporization chamber.

In normal operation, the water in the vaporization chamber submerges the body of the probe and the main resistance thermometer of the vaporization chamber heats the water generating the steam.

The electrical resistance thermometer of the probe heats the body of the probe itself while the thermostat of the probe continuously monitors the temperature of the probe itself.

The probe comes out of the water in whole or in part when the water to be vaporized decreases in level and consequently the heat generated by the thermoresistance of the probe increases the temperature of the probe itself. This increase in the temperature of the probe is detected by the thermostat which activates the pump by taking water from the tank and introducing it into the vaporization chamber. The added water hits the probe, cooling it. The probe itself cools down when the water level has risen reaching the lower limit temperature; at this point the thermostat commands the stop of the filling pump.

Both the dimensions, the materials, and the thermal and thermoelectric characteristics of the various parts of the probe are studied and related in order to have a high sensitivity of the probe. A very small difference in level is obtained between the maximum level and the minimum level of water in the vaporization chamber.

The steam generator constructed as described above has considerable advantages:

Maintains a substantially constant level of the water to be vaporized with consequent stability of water-vapor-pressure relationships,

• introduces smaller quantities of cold water, drastically reducing the internal temperature changes of the vaporization chamber,

• has a more homogeneous production of steam and a less variable pressure value,

• high sensitivity to changes in water level,

• there are no malfunctions due to limescale,

• continuous operation even in positions that are not perfectly horizontal, elimination of electrical imbalances or other.

For explanatory and non-limiting purposes of the characteristics of the present invention, an example of embodiment of the system according to the invention is now described, with reference to the annexed schematic drawings.

Figure 1 shows the new steam generator, while figures 2 and 3 show the two moments of low and high water level.

The cold water tank (1) is equipped with a level reader (2) which, by means of the acoustic signal or warning light (3), warns the user of the lack of water.

The vaporization chamber (6) heats the water contained in it through the main resistance (7). At the same time the resistance (12.2) of the probe (12) heats the body (12.1) of the probe (12) itself and the heat is absorbed by the water of the vaporization chamber (6).

When the preset pressure is reached, the pressure switch (9) cuts off the power supply to the resistances (7, 12.2). The steam is delivered by means of a solenoid valve (10) operated by a control button of the steam utilization equipment. The consequent lowering of pressure triggers the pressure switch (9) which reinserts the main resistance (7) to maintain the operating pressure and the resistance (12.2) of the probe (12).

When the water inside the vaporization chamber (6) falls below the level (X, figure 2) of the probe body, the heat generated by the electrical resistance (12.2) overheats the probe body (12.1) and the thermostat ( 13) of the probe itself activates the pump (4) for topping up.

The pump (4) takes the water from the tank (1) and introduces it into the vaporization chamber (6) through a nozzle or filling hole (8) so that the incoming water invests or in any case licks the probe (12 ).

As soon as the water level rises above the level of the probe (Y, figure 3) the greater heat of the body (12.1) of the probe (12) generated by its resistance (12.2) has been absorbed by the water of the vaporization chamber ( 6) and consequently the thermostat (13) intervenes again, interrupting the operation of the pump (4).

This system allows for frequent and short injections of cold water so as not to compromise the pressure that has formed inside the boiler.

In this way the curve indicating the pressure values (p) of the new system (n) with respect to time (t) is less wide than the traditional systems (v) and the pressure excursion during the working and working phase is reduced. sampling, as shown in figure 4.

The traditional pressure switch detects the pressure (with a much lower delta) and therefore is activated only in the case of the end of work, thus avoiding the intervention of the pressure switch which disconnects the main water heating resistance during the refill phase and thus allowing continuous and effective work. .

Claims (5)

CLAIMS 1. Steam generator with main resistance characterized by having a water level probe consisting of a heat conducting body, an electrical resistance thermometer and a thermostat, and where the heat conducting body has a generally linear shape with a connection flange at one end to the wall of the steam generators, and where the thermo-resistance is contained in whole or in part inside the heat-conducting body, and where the thermostat is applied to the heat-conducting body in a suitable position such as to detect the thermal variations of said probe. 2. Steam generator as per claim 1, characterized in that said level probe is applied to the wall of the vaporization chamber at a height comprised between the maximum and minimum levels of the water to be vaporized, and where the thermostat is connected to the steam generator top-up pump by activating and deactivating it according to the temperature of the probe. 3. Steam generator as per claims 1, 2, characterized in that the vaporization chamber is filled by means of a pump, which takes water from an accessory tank, which is activated or deactivated by said probe. 4. Steam generator as per claims 1, 2, characterized by the fact that the probe is inserted in whole or in part inside the vaporization chamber, equipped with a main resistance, in an area where it is subject to both complete drowning in the refill water is at complete emersion. 5. Steam generator with probe as per claims 1, 2, characterized by the fact that the top-up water inlet is placed exactly above the probe or in any case the filling water affects or touches the probe.