Pneumatic composite having mass balancing

Abstract

A blower device for delivering at least one medium includes a blower having a housing with an inlet and an outlet, a nozzle, which is fluidically connected and arranged on the housing such that at least one medium can flow there through. The nozzle is designed to effect a negative pressure on the at least one medium at least in some sections. At least one sensor is arranged in the effective region of the nozzle and designed to measure at least parameters of the at least one medium which are required to determine the mass of the at least one medium.

Claims

1. A mixer blower device for mixing air and a gas, the mixer blower device comprising: a. a mixer blower having a housing with an inlet and an outlet, b. a nozzle, which is fluidically connected and arranged on the housing such that the air can flow through the nozzle, the nozzle being designed to effect a negative pressure on the air flowing through the nozzle, and c. a mass flow sensor arranged in an effective region of the nozzle and designed to measure a mass of only the air flowing through the nozzle; wherein the nozzle has a supply element having a gas valve via which the gas is supplied by means of the negative pressure generated by the nozzle, a supplied quantity of the gas being controlled exclusively by the negative pressure of the air flowing through the nozzle, the supplied quantity of the gas being determined based on an opening position of the gas valve, and the opening position of the gas valve being pneumatically determined by the negative pressure of the air flowing through the nozzle; the mass flow sensor is electronically connected to a control system or a regulation system, the control system or the regulation system receives the mass for the air from the mass flow sensor as a value via an electronic signal line; the control system controls a speed of an impeller of the blower as a function of the value of the mass of the air flowing through the nozzle measured by the mass flow sensor, or the regulation system regulates the speed of the impeller of the blower as a function of the value of the mass of the air flowing through the nozzle measured by the mass flow sensor until the measured value corresponds to a set value stored in the regulation system; and the control system or the regulation system includes a storage device that stores a predefined characteristic curve, which determines the speed of the impeller of the blower as a function of a heating output required for a burner.

2. The mixer blower device according to claim 1, wherein an electronic evaluation unit is provided which receives a sensor signal from the mass flow sensor, the electronic evaluation unit converting the sensor signal to an electronic signal which is assigned to the mass of the air.

3. The mixer blower device according to claim 1, wherein the nozzle has an additional channel through which at least part of the air flows, the mass flow sensor being arranged in the additional channel.

4. The mixer blower device according to claim 3, wherein the additional channel runs substantially parallel to the nozzle and leads into a region of the nozzle which lies in front of a nozzle section, in the direction of flow, in which the cross-section of the nozzle is minimal.

5. The mixer blower device according to claim 1, wherein the nozzle has at least two supply lines for the air, the second supply line being designed in the form of a channel and the mass flow sensor being arranged within the second supply line.

6. The mixer blower device according to claim 1, wherein the nozzle is designed as a Venturi nozzle and is arranged such that it is directly connected to the inlet of the housing.

7. The mixer blower device according to claim 1, wherein the blower is designed as a radial blower for burners premixing the air and the gas, wherein said premixing takes place at least partially via the nozzle.

8. A method for regulated operation of the mixer blower device according to claim 1, the method comprising: arranging the mass flow sensor in the effective region of the nozzle, measuring the value of the mass of the air flowing through the nozzle, passing the measured value to the regulation system via the electronic signal line, the regulation system regulating the speed of the impeller of the mixer blower as the function of the value measured by the mass flow sensor until the value measured by the mass flow sensor corresponds to the set value stored in the regulation system, regulating the speed changing a quantity of the gas supplied to the nozzle pneumatically with respect to a change in mass of the air.

9. The method according to claim 8, wherein the quantity of the gas supplied to the nozzle is changed at substantially the same time and in a linear relationship to the change in mass of the air by controlling or regulating the speed.

10. A method for controlled operation of mixer blower device according to claim 1, the method comprising: arranging the mass flow sensor in the effective region of the nozzle, measuring the value of the mass of the air flowing through the nozzle, passing the measured value to the control system via the electronic signal line, the control system controlling the speed of the impeller of the mixer blower as the function of the value measured by the mass flow sensor, controlling the speed changing a quantity of the gas supplied to the nozzle pneumatically with respect to a change in mass of the air.

11. The method according to claim 10, wherein the quantity of the gas supplied to the nozzle is changed at substantially the same time and in a linear relationship to the change in mass of the air by controlling or regulating the speed.

12. The mixer blower device according to claim 1, wherein the nozzle includes a narrow cross-section disposed between an inlet and an outlet of the nozzle, the narrow cross-section having a cross-section smaller than a cross-section of the inlet of the nozzle and smaller than a cross-section of the outlet of the nozzle.

13. The mixer blower device according to claim 12, wherein the cross-section of the inlet of the nozzle is the same as the cross-section of the outlet of the nozzle.

14. The mixer blower device according to claim 1, wherein a cross-section of an inlet of the nozzle is the same as a cross-section of an outlet of the nozzle.

15. A mixer blower device for mixing air and a gas, the mixer blower device comprising: a. a mixer blower having a housing with an inlet and an outlet, b. a nozzle, which is fluidically connected and arranged on the housing such that the air can flow through the nozzle, the nozzle being designed to effect a negative pressure on the air flowing through the nozzle, and c. a mass flow sensor arranged in an effective region of the nozzle and designed to measure a mass of the air flowing through the nozzle; wherein; the nozzle has a supply element via which the gas is supplied by means of the negative pressure generated by the nozzle, a supplied quantity of the gas being controlled by the negative pressure of the air flowing through the nozzle; the supply element includes a gas valve, the supplied quantity of the gas being determined based on an opening of the gas valve, and the opening of the gas valve being pneumatically controlled by the negative pressure of the air flowing through the nozzle; the mass flow sensor is electronically connected to a control system or a regulation system, the control system or the regulation system receives the mass of the air from the mass flow sensor as a value via an electronic signal line; the control system controls a speed of an impeller of the mixer blower as a function of the value measured by the mass flow sensor, or the regulation system regulates the speed of the impeller of the blower as a function of the value measured by the mass flow sensor until the measured value corresponds to a set value stored in the regulation system; and the control system or the regulation system includes a storage device that stores a predefined characteristic curve, which determines the speed of the impeller of the mixer blower as a function of a heating output required for a burner.

Description

(1) The invention is illustrated schematically by way of example in the figures below, the same reference numerals being used to identify identical elements.

(2) These are as follows:

(3) FIG. 1 is a schematic view of the blower device according to the invention,

(4) FIG. 2 is a schematic representation of an alternative embodiment of the nozzle

(5) FIG. 3 is a schematic representation of another alternative embodiment of the nozzle.

(6) FIG. 1 is a schematic representation of a device comprising a blower 1 for delivering a mixture of air and gas. The blower 1 has a housing 2 with an inlet 3 and an outlet 4, a nozzle 5 being fluidically connected directly to the housing 2 at the inlet 3. A blower impeller 12 driven by a motor 10 is arranged inside the housing 2. The nozzle 5 is designed as a Venturi nozzle, an inlet region with a large cross-section tapering to a section with a much narrower cross-section in accordance with this type of nozzle, the cross-section then widening again towards the inlet 3 of the housing 2 to substantially return to its original value. Operating the blower impeller 12 generates a flow. In this process, air is taken in through the Venturi nozzle 5, amongst other things, and accelerated in the region with a reduced cross-section, thus forming a negative pressure. A supply element 8 is arranged on the Venturi nozzle 5 in the region with a reduced cross-section, through which the fuel, preferably gas, can be supplied. The quantity of gas supplied is determined as a function of the opening position of the gas valve 13, which is affected by the negative pressure of the nozzle 5 and determines the opening position. The quantity of gas supplied is thus directly and linearly dependent on the negative pressure value, i.e. the speed of the blower impeller 12. The sensor 6 for determining the air mass flowing through the Venturi nozzle 5 is arranged in the effective region of the Venturi nozzle 5. In the illustrated embodiment, the sensor 6 is fixed to the inner wall of the Venturi nozzle 5 in such a way that the sensor 6 is exposed directly to the main flow of the incoming air. In the schematic representation, the sensor 6 is shown in enlarged scale next to the Venturi nozzle 5, this sensor being electronically connected to a regulation system 9 via an electronic signal line 11 and passing the measured values to the regulation system 9 via the signal line 11. The regulation system 9 is connected to the motor 10 to adjust the speed of the blower impeller 12 as a function of the values measured by the sensor 6.

(7) FIG. 2 illustrates an alternative embodiment of the Venturi nozzle 5, the remaining elements being assumed to be identical to FIG. 1. The nozzle 5 has an additional channel 7 in the inlet region in which the sensor 6 is arranged. An ancillary flow is taken in through the additional channel 7, this being designed such that the mass of the main flow can be estimated by measuring the ancillary flow. The losses in a well-designed Venturi nozzle 5 are so minimal that they can easily be tolerated. The additional channel 7 runs substantially parallel to the outer wall of the nozzle 5 and leads back into the main flow of the nozzle 5 in a region which lies in front of the nozzle section, in the direction of flow, in which the cross-section of the nozzle 5 is minimal.

(8) FIG. 3 shows another alternative embodiment of the arrangement of the sensor 6, the features not illustrated in FIG. 1 also being used in this embodiment. The nozzle 5 has two supply lines, a first supply line conveying a main flow and a second supply line conveying an ancillary flow. The sensor 6, which measures the supplied air mass and conveys it to the regulation system via a signal line, which is not illustrated, is arranged in the second supply line, which is substantially channel-shaped.

(9) During operation of the blower 1 as shown in FIG. 1 or the embodiments shown in FIGS. 2 and 3, the air mass taken in via the blower impeller 12 is measured using the sensor 6 and the measured value is passed via an electrical signal line 11 to a regulation system 9, the regulation system regulating the speed of the impeller 12 of the blower 1 as a function of the value measured by the sensor 6 until the measured value corresponds to a set value stored in the regulation system 9. The sensor 6 is arranged in the effective region of the Venturi nozzle 5 and measures the mass of combustion air passing through the Venturi nozzle 5. The Venturi nozzle 5 creates a negative pressure as the air flows through, this pressure affecting the opening position of the gas valve via a supply element 8 or an additional line, and thus creating a wider opening position of the gas valve 13 and thus a greater amount of gas supplied as a result of a greater negative pressure in the presence of larger air masses. By changing the speed of the impeller 12, the quantity of gas supplied is adjusted accordingly both automatically and pneumatically. This adjustment takes place at substantially the same time and in a linear relationship to the change in the supplied air mass.

(10) Alternatively, a control system 9 can be used instead of a regulation system 9, the speed being controlled via a stored characteristic curve, but the value achieved is not returned and checked against a set value.

(11) The invention is not limited to the preferred embodiments described above. Instead, there are a number of conceivable alternatives which make use of the illustrated solution even in embodiments which are fundamentally different. For example, if the air mass is not measured directly by the sensor, an electronic evaluation unit may be provided which evaluates a signal from the sensor and converts it to an electronic signal which can be assigned to the mass flowing through.