FR2688578A1 - Regulating unit for a premix liquefied-gas burner - Google Patents

Abstract

Regulating unit for a premix liquefied-gas burner comprising a comparator circuit measuring the effective temperature of a fluid heated by the burner, by means of a heat exchanger, and being subject to the action of a reference signal generator, and which acts on a valve feeding gas to the burner depending on the result of the reference/effective temperature comparison. The comparator circuit (16) is followed by a time-delay member (19) which the comparator circuit (16) can trigger as soon as the effective value has come sufficiently close to the preset reference, the time-delay member (19) acting during its functioning on the assembly (10, 18) feeding the burner with fuel as if there was an increase in the charge of the burner.

Description

The present invention relates to an adjustment unit

  for a single premix liquefied gas burner

  only with primary air, including a circuit

  parator measuring the effective temperature of a fluid heated by the burner, via a heat exchanger, and undergoing the action of a set signal generator, and which acts on a valve ensuring the gas supply to the burner according to the result of

  the setpoint / actual temperature comparison.

  On pre-mix burners of the above type

  tee running on liquefied gas, noises may arise at

  time of flame extinction due to the closure-

  re the valve if the burner is stopped during a run

  reduced load If the primary air share increases,

  these noises can reach a level such as the use

  tion of liquefied gas is no longer possible.

  On known control units, the load of the burner

  their is reduced if the difference between the setpoint and the actual value decreases, and the burner supply

  is cut if the two values are close enough

  healthily from each other But this cut causes

more or less loud noises.

  The present invention therefore aims to avoid these

  disadvantages and to propose a suppressing adjustment unit

  mant noises at the time of extinction of the flames.

  This goal is achieved by the fact that the comparator circuit

  is followed by a timer that the circuit compares

  erator can trigger as soon as the actual value has

  sufficiently close to the preset setpoint, the organ-

  -2 no timer acting during its operation on the valve supplying the burner with fuel as if it

  there was an increase in the burner load.

  This procedure ensures that the burner load, shortly before it is extinguished, is increased for a short time so that the cut-off is made at the time of a high burner load, which avoids the above-mentioned noises. According to another characteristic of the invention, it can in this context be expected that the operation of

  the timer element lasts approx. 3 seconds.

  This ensures that the burner is under a char-

  sufficiently high age before cutting off the fuel supply, without however during this brief lapse of

  time there is wasted energy.

  Hereinafter, the invention is described with the figures of the drawing in support, which show:

  Fig 1, the diagram of a heating installation

  tee of an adjustment unit according to the invention;

  Fig 2, the diagram of the adjustment unit for the ins-

  heating installation according to fig 1.

  In the heating installation according to FIG. 1, a heat exchanger 1 is heated by a burner 2 arranged at the bottom of a heating chamber 3 which channels the

  burnt gases on the heat exchanger 1.

  The burner 2 comprises several mixing tubes 4 supplied with liquefied gas by a distributor tube 5 In addition, the burner 2 comprises a cooling system

  6 which is connected upstream and downstream of a circulating pump

  culation by pipes 7, 8 on the return 14, the pump

  eg pumping a fluid to be heated towards the heat exchanger

their 1.

  The gas supply to the distributor tube 5 is as-

  secured by a proportional effect solenoid valve 10, which

  undergoes the action of an adjustment unit 11 and a regulation

pressure tor 18 mounted downstream.

  -3- The primary heat exchanger 1 is connected by a

  flow pipe 12 to a set of heating radiators

  fage 13 which is connected, by a return pipe 14, in the-

  what is the circulation pump 9 planned for?

says heat exchanger 1.

  In the outlet pipe 12 is provided a thermometer

  mometric 15 which is connected to the adjustment unit 11 which

  further includes a setpoint signal generator 17.

  As shown in fig 2, the thermometric probe

  that 15 is connected to the comparator circuit 16 on the input of which is also connected the signal generator

  instruction 17 On the other hand, at the output of the compa-

  timer 16 is connected to a timer 19 which commu-

  nique with the pressure regulator 18 which is also connected

  if directly to an output of the comparator circuit 16 by a line 21 Likewise, the solenoid valve 10 is connected to a

  output of comparator circuit 16 by line 22.

  A signal is emitted by the comparator circuit 16 for

  open the solenoid valve 10 when a sufficient difference

  large is reached between the flow temperature and the preset temperature preset on the set signal generator 17, signal applied directly to the solenoid valve 10 which opens, the pressure regulator 18 receiving a corresponding signal to adjust the load

of the burner 2.

  If the difference between the actual value and the

  sign goes down to a determined value, the temporal organ

  sator 19 is triggered and sends to the pressure regulator

  sion 18 a signal which increases the power of the br -

  their At the same time, the solenoid valve 10 is maintained in

  position opened by the output signal from the temporary organ

  gatekeeper 19 while the corresponding signal from the

cooked comparator 16 disappears.

  After the timer 19 has stopped, the signal ensuring the opening of the solenoid valve 10 for approx 1 to 3 seconds disappears, and the solenoid valve closes, which

4 _ 2688578

stops the burner.

  Due to increased burner load

  2, noises normally arising when such burns stop

  their premixed with liquefied gas are removed.

Claims (2)

R E V E N D I C A T I O N S   1 control unit for a liquefied gas burner premixed only with primary air,   comprising a comparator circuit measuring the temperature   effective erasure of a fluid heated by the burner, via a heat exchanger, and   bissant the action of a signal generator of   sign, and which acts on a valve ensuring the supply   gas ration of the burner according to the result of the   setpoint / actual temperature comparison, characteristic   laughed at by the fact that the comparator circuit (16)   is followed by a timer (19) that the circuit   cooked comparator (16) can trigger as soon as the   their workforce is close enough to the   preset setpoint, the timer member (19) acts   during its operation on the assembly (10, 18) supplying the burner with fuel as if it   there was an increase in the burner load.   2 adjustment unit according to claim 1, charac-   terrified by the fact that the functioning of the organ-   no timer - (19) lasts for about 3 seconds.