DE1250955B - Electrical monitoring device for burner systems - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

UTSCHES

PATENT OFFICE

EDITORIAL

Int. Cl

F23n

German class: 24 m -3

Number 1250 955

File number. St 195821 a / 24 m

Filing date: August 9, 1962

Display day. September 28, 1967

V '/ .C

The invention relates to an electrical monitoring device for burner systems, with a thermal safety switch and an optical one Flame monitoring device

There are only known electrical monitoring devices for burner systems, in which the fuel supply in Dependence on the light of the flame is influenced in such a way that when the flame is extinguished Fuel supply is interrupted Also it is no longer new to achieve this photosensitive effect To use means such as photocells. A photocell works either with a sensitive one Relay that works directly due to the current flow through the photocell, or it is connected to a less sensitive relay, which requires an amplification of the signal current through the cell. Instead of an optical one Relays that react to influences have also devices that respond to the temperature of the exhaust gases used

These known control devices have a very complex structure and have numerous electrical devices are therefore particularly prone to failure and for this reason do not guarantee efficient work with absolute certainty the monitoring device On the other hand, attempts have been made to get by with simpler control systems, but one had to do without one or the other safety device this monitoring device does not work satisfactorily, for example when the fuel has not ignited within a certain time, the flame goes out, the power fails or any of the facilities has malfunctions

The invention was based on the knowledge that the previously known monitoring devices for burner systems are not yet with the required security against interference

It was therefore the task to solve a monitoring device to develop that practically against all malfunctions occurring in the burner system appeals to

The solution to this problem is that in emem circuit em bimetal switch with the heating resistor of the safety switch is connected in series, this circuit being a second circuit is connected in parallel with a much lower resistance and in this second circuit the Flameguard arrest intervenes

The present monitoring device has a Bunetallsafety switch that the burner

Electrical monitoring device for
Burner systems

Applicant.

White-Rodgers Limited,
Maikham, Ontario (Canada)

representative

Dr. H Wittek, patent attorney,

Heidelberg-Schherbach, Im Grund 20

Claimed priority

Canada February 10, 1962 (842 014)

turns off if the fuel is not within a

so certain time is ignited, and also has emen light-responsive switch that disables the safety switch when the Fuel is ignited. There is also a branch circle low Widei level parallel to the heating resistor of the safety switch, the emen relay contact contains, which is closed when the burner is switched on, and which also emen silicon controlled rectifier included in Series is connected to this contact and is considered to be more sensitive Switch is used. The silicon controlled rectifier is normally open and has em Control element, which is connected to a flame-responsive element in the m series Resistance in the opposite behavior to the amount of light falling on it stands The control circle is designed so that its resistance decreases when responsive to the flame Element is illuminated this increases the Potential at the control element in such a way that the signal-controlled rectifier ignites and the The heating resistor of the safety switch switches off. The invention provides an automatic one

Control system for burners, which with security on failure of ignition, going out of the Flame, power failure, non-response of the light-sensitive element and failure of individual Appeals to parts

Another advantage of the invention is the creation of a positive acting, simple burner control system the flame control version, which is a minimum of relatively inexpensive Components required

709 649/155

3 4

Further objects and advantages of the invention result in sufficient light being obtained directly or by reflection, from the following description of the conductivity required for its work

Drawing shown embodiment, while it is the other hand in the absence

With the monitoring device according to the drawing of the burner flame, sufficient against outside light

tion is the Antnebsmotoi 12 'of the oil burner 10' 5 is protected

via the current containing the relay contact 203. The relay contacts 201, 202 and 203 are Circuit 209 parallel to the primary winding 56 'of the Trans- simultaneously actuated by the motor relay coil 20' formator switched by a suitable. When this is de-energized, contacts 201 and closes

Alternating current source is fed in parallel to the opening of the contacts 202 and 203 In the simplest case, circuit 209 is via conductor OK

74 and 76 of the transformer 54 switched, with des- mode of operation

sen secondary winding the ignition device 52. It is assumed that in the case of the illustrated

is connected to the control system the room thermostat 14 'closes,

The oil burner 10 'contains in the usual way that the burner is to be switched on.

Blower and the fuel pump, which when they 15 coil 20 'is then energized via a current path, the

driven by motor 12 ', secondary burner coil 58', conductor 213, safety switch 30 ',

nerduse a mixture of remote-dusted oil and conductors 212 and 211, diode 204, room thermostat 14 ',

Supply combustion air, which is then passed through conductor 210, motor relay coil 20 ', conductor 214, heating

Sparks at the electrodes of the ignition device 52, resistance 40 ', conductors 215 and 216, heating resistor

Ao 32 ', coil switch 38' and conductor 217 is ignited. As a result

With one side of the transformer secondary excitation of the motor relay coil 20 ', the close

coil 58 'is one end of the motor relay coil 20' relay contacts 202 and 203 and opens relay con-

Via conductor 210, room thermostat 14 ', which on the clock 201 The closing of the relay contact 203

The temperature of the heated by the burner leads to the activation of the Antnebsmotors 12 '

Room responds, diode 204, conductors 211 and 212, 25 circuit 209, and by closing the relay

Bunetallfeder 30 'of the thermal safety switch contact 202 is the cathode of the silicon-controlled

ters and conductor 213 connected th rectifier 206 to the secondary coil 58 'of the

The other ends of the motor relay coil 20 'and Tiansformators connected so that the like the Transfoimatoi secondary coil 58 'are ready to work over 206 because the light-dependent resistor 214, heating resistor 40 'of the spool switch, 30 stood 50' is not yet illuminated, is its resistance 215 and 216, heating resistance 32 'of the safety stand very high (in the order of magnitude of safety switch, bimetallic spring 38 'of the spool switch 10 million ohms) and the control element and conductor 217 connected. Diode 205 is flier relay coil for motor 206 α of the silicon-controlled rectifier 20 'connected in parallel ßende current so small that the rectifier 206

The safety switch is normally in the open circuit state However, if the bimetal spring 30 'closed, if the ignition is not within a certain specified For a while by the heating resistor 32 'th time, the heat generated by the is heated and this receives full current, it bends through the heating resistor 32 'flowing current entich through and thereby opens the contact. It winds the bimetallic spring 30 'of the safety switch negulated in the open position and must be deformed by hand 40, whereby the motor relay coil 20 'is de-energized be switched on again This type of safety circuit and the motor circuit 209 of the internal combustion engine 12 ' switch is commonly used. Its construct- is opened

tion and mode of operation are on the relevant Assuming that the contacts of the switches 30 ',

Is known in the art 14 'and 38' are closed and that burner 10 '

There is a circuit to short-circuit the heater 45 is ignited, so the light from the burner flame falls

Resistor 32 'of the safety switch is provided on resistor 50' and sets its resistance

This contains a silicon-controlled rectifier down to approximately 2000 ohms.

206, the anode of which with the junction b of the resistance causes such an increase

Conductor 215 and 216 is connected via conductor 218 of the current flow to the control element 206 a that the

and whose cathode becomes conductive with the junction of the 50 silicon-controlled equivalent 206. There

Conductor 217 and the transformer secondary coil 58 'the resistance of the current path, which conductor 218,

via conductors 219 and 220, relay contact 202 and rectifier 206, conductors 219 and 220, relay contact

Conductor 221 is connected to clock 202 and conductor 221 is longer than the

The silicon-controlled equivalent 206 is one of the current path, which conductor 216, Heizaus four layers of existing PNPN semiconductors with 55 resistance 32 ', coil switch 38' and conductor 217 entemem Control element 206a, which with the behavior, is m this way the heating resistor 32 'des Bmdungsstelle α of conductor 210 and motor relay coil of safety switch effective by short circuit 20 'via conductor 224, high-dependent resistor 50' switched off the system. A larger one flows and conductor 225 is connected to current via the heating resistor 40 'of the coil switch,

The photosensitive element 50 'consists of 5o and after a certain time the bimetallic

a semiconductor, which in the absence of light of the spring 38 'heated so far that their deformation to

Burner flame an extremely high electrical opening of the conductor 217, bimetallic spring 38 'and

see resistance, leads under the action of the Lieh heating resistor 32 'existing current path

However, the burner flame is sufficiently conductive. As a result, the heating resistor 32 'has no effect

The light-sensitive element 50 'is placed in front of 65 more on the bimetallic spring 30'

part of the interior of the burner housing by igniting the rectifier 206 for

End of the blowpipe attached It was fixed - the motor relay coil 20 'em holding circle formed,

placed that the element at this point either consists of secondary coil 58 ', conductor 213,

Safety switch 30 ', conductors 212 and 211, permanent locking diode, as described above with reference to the

204, room thermostat 14 ', conductor 210, motor relay - failed ignition was described,

coil 20 ', conductor 214, heating resistor 40', conductor 215 If, thirdly, the power fails, without

and 218, rectifier 206, conductors 219 and 220, considering the duration, will motor relay coil 20 '

Relay contact 202 and conductor 221 5 de-energized, and the same effect occurs as they do

After the burner 10 'has had enough heat on hand of the flame going out

supplies has been described to the temperature of the heated room

on the setting of the room thermostat 14 'if fourth, a short circuit between points

bring, the thermostat opens, so that the and control element 206 α enters - the occur

Motor relay coil 20 'is de-energized and the relay io can, if there is a short circuit in resistor 50'

Contact 203 opens, which leads to the shutdown of the or is exposed to the wrong light, ie

Antnebsmotors 12 'leads The bimetallic spring 38' cools other light than the burner flame - so will

and closes the branch circuit again, the control system for these errors with certainty

Conductor 217, coil switch 38 ', heating resistor 32' and react as the control element 206 «receives power

Conductor 216 exists Since the burner flame is extinguished 15 and rectifier 206 consequently ignites.

lst, Widei resumes its high position 50 ', a current path is established over seconds

Resistance to and rectifier 206 is non-darspule 58 'of the transformer, conductor 217, coil

conductive switch 38 ', heating resistor 32' of the safety switch

The diode 206 serves as a buffer, which the verters, conductors 216 and 218, rectifiers 206, conductors

Use of the cheaper DC relay 20 'enables 20 219 and 223, relay contact 201, conductors 222 and 212,

light diode 204 prevents jerk current to safety switch 30 'and conductor 213 The safety

Silicon-controlled rectifier 206 flows into switch 30 'is therefore within approximately one

if you leave diode 204 out of the circuit, open it for a third of the time described above and that

was Gleichnchier 206 power during the positive control system permanently switch off

Let through tive half-waves of the alternating current «5 Fifthly, the control circuit also has a say

and the current during the negative half-wave safety on the failure of individual parts. if

lock Under these circumstances, the rectifier 206 has interrupted its circuit,

Safety resistor 32 'during the negative occurs the same control sequence em as above

Half-waves be conductive and therefore finally described in relation to the failure of the ignition

Open safety switch 30 '. If a short circuit occurs in the rectifier,

Instead of the diode 204 in the manner shown, the control system behaves as above in FIG

to be arranged in the circuit, it can also be used for connection with the failure of the flame

Correct circuits of the ignition relay circuit in series trolle is described If the diodes 204 or

to the motor relay coil 20 '. If at- 205, the motor relay coil 20 'or the heating resistor

For example, the ignition relay circuit between points a 35 stands 32 'or 40' does not work, the control

and b is applied, the diode 204 at point c system cannot operate the burner

m series to the motor relay coil 20 'are connected, albeit element 206 as a silicon controlled

The arrangement has the following safety rectifier is described, but it goes without saying that it remains: in the thyratron).
State of high resistance and thus holds the In the above description, the be-Gleichnchter 206 was in a non-conductive state Since the preferred form and embodiment of the invention be-heating resistor 32 'of the safety switch in the It goes without saying, however, that the circuit remains The bimetallic spring 30 'wards 45 various changes and modifications and opens after a certain time, so that the device described is de-energized and consequently the motor relay coil 20' is de-energized without the other motor circuit 209 being opened by the contact of the languages described deviate from the invention
Safety switch 30 'can only be operated by hand. It is therefore within the scope of the invention if the 50 ignition device is not switched on again as a continuous ignition at the same time as the motor is switched on for a specific cooling time, with the rest being switched on

Second, the circuit is automatically opened, no detrimental effect on the relay switch the burner flame goes out under the pre-cycle 203 occurs that the control circuit imitates all of them via an ignition relay Has carried out steps, motor relay coil 20 '55 is this purpose, the line 74 through a switch the holding circuit described above is energized If the interrupted, which is controlled by the ignition relay the flame goes out or is temporarily interrupted the resistance of the hchtabhan- spule increases with the circuit between the heating resistor gigen resistance 50 'immediately so worth that equal 32' and coil switch 38 'connected, while the after 206 is deleted. This switches the motor relay 60 to the other end of the ignition relay coil via a diode in coil 20 'is de-energized and motor circuit 209 is open. That leads to the conductor 210. The installation of this diode is The work of the Brennei is stopped immediately a certain time the coil switch closes current flow from the right side of the secondary winder 38 ', since the treatment 58 'supplied by the heating resistor 40' is caused by the safety switch 30 ', room warmth missing The control circuit now repeats the 65 thermostat 14 ', ignition relay winding, heating resistor initial startup sequence, trying so the burner 32 ', silicon controlled rectifier 206 and relay flame re-ignite if the flame does not contact 202 to the left of the secondary winding appears within a certain time, the 58 'takes place to avoid otherwise the effect was

manner of the necessary to control the ignition device Bobbin switch canceled and the safety switch 30 'respond constantly

Claims (2)

Patent claims 1. Electrical monitoring device for burner systems with a thermal safety switch and an optical flame monitoring device, characterized in that a bimetal switch (38 ') with the heating resistor (32') of the safety ^{switch (300 m in} series) is connected in a circuit, this circuit being a second circuit (Conductors 218 to 221 with rectifier 206 and relay contact 202) is connected in parallel with a significantly lower resistance and the flame guard device (50 ') intervenes in this second circuit. 2 Electrical monitoring device according to claim 1, characterized in that a normally open short-circuit switch (206) is placed in the second circuit, which is closed by the influence of the burner flame on light-sensitive means (50 '). Documents considered.
German outbuildings No. 1069 806,
302,
Swiss patent specification No. 352 083 1 sheet of drawings 709 649/155 9 67 © Bundesdruckerei Berlin