DE1199240B - Process and device for the automatic regulation of the voltage of an electrostatic dust collector - Google Patents

Description

GERMAN

PATENT OFFICE

EDITORIAL

German class: 12 e-5

Number:
File number:
Registration date:
Display day:

1199 240
B61329III / 12e
17th February 1961
August 26, 1965

The German patent 1080 979 is one such Process for the automatic control of the voltage of an electrostatic dust collector has become known, in which an interplay of tension-increasing and tension-reducing Impulses acting on the variable transformer and in the case of which, in addition to the number of in a certain The flashover intensity for determining the voltage change is used.

According to this method, the filter voltage is automatically adjusted so high that a certain Rollover power occurs. Under the existing operating conditions, this causes a sufficiently high power consumption of the electrostatic dust collector within adjustable Limits, whereby by setting the target value the number and intensity of the rollover a favorable amount for the temporal mean value of the total degree of dedusting is achieved.

According to a preferred embodiment of the main patent, depending on the number and Strength of the flashovers regulated in such a way that directed according to the respective control deviation Current pulses act at time intervals on the drive motor of the regulating transformer, which increase or decrease the voltage respectively.

According to the invention, this method is further developed in such a way that only the additional electricity or watt-hour consumption due to the flashovers, the current consumption of which _{exceeds a permissible adjustable value (/ perm} ), is used as the actual value for the control. Compared to the method according to the main patent, the specified current strength / _{zuI reduces} the area size b of the time integral of the flashover pulses

J (TI ₀ ) dt to the new area size c of the time integral

Procedure and device for automatic
Regulation of the voltage of an electrostatic
Dust collector

Addendum to the patent: 1080 979

Applicant:

Dr.-Ing. Herbert Brandt,

Rothemühle via Olpe (Westf.)

Named as inventor:
Dr.-Ing. Herbert Brandt,
Rothemühle via Olpe (Westf.)

J (I-hui) dt

and prevents a disadvantageous downward regulation of the electrical power in the E-filter if the current temporarily drops to a lower value I _{0 due to changing operating conditions.}

A further simplification of the new process is achieved in a manner known per se by that the response time of the control device is set so that very small, short flashovers are not covered by the measurement.

The new method and the facilities used to carry it out are shown in the drawing in preferred embodiment shown.

F i g. 1 shows a device for detecting the

for the process decisive measurands in the scheme, shown are parts of a three-phase four- '

>, ladder counter with a pointer switching device after the Main patent;

Fig. 2 is an example of the entire circuit of an electrostatic precipitator using the measuring and Control devices that are also included in the main patent ·.;. to be used preferentially;

F i g. 3 summarizes the main measured values to be observed in the scheme.

In detail, the figures illustrate the following process sequence and the associated ones Facilities.

A variable transformer 4 is connected to a low-voltage distribution with the alternating current phases R and S via the fuse elements 1, the main contactor 2 ', the overcurrent relay 3. Between. see this and the high-voltage transformer 10 is another overcurrent relay 6 to protect the system. The high-voltage transformer 10 is supplied via a rectifier bridge 11, the positive

509 658/426

tive pole is connected to earth via a protective resistor 13, the spray electrodes of an electrostatic precipitator 12 with high voltage direct current. The collecting electrodes of the electrostatic precipitator are under the insertion of a Protective resistor 32 to earth. The trip contact 3 'and an auxiliary contactor are used for the overcurrent relay 3 33 arranged; for the overcurrent remsS a second one Contact 9 '.

The rectifier bridge 20 belongs to the mains current transformer 19 for the control current Switching on the system by means of button 31, the auxiliary contactor 25 is connected to voltage. Contact 25 ' this contactor closes and at the same time sets the main contactor and the timer 16 with the two pulse relays 17 and 18 under tension. The contacts 2 'of the main contactor then switch the high-voltage rectifier a.

Electricity meters 7 or T or 7 ″ are connected at a suitable point to the power supply line to the electrostatic precipitator.

The flashover current in the main circuit is detected, for example, by means of a current transformer 5 in the current coil of the counter 7. An overcurrent relay 8, which actuates the switch 9, can be connected in parallel with the current transformer 5. This means that the meter will only record part of the watt-hour consumption within the time during which a flashover occurs (see area «in the diagram of the main patent). However, a second counter 7 ″ can act in the opposite direction of rotation on the measuring mechanism shaft in such a way that a controllable current I. _{ml is} subtracted from the main current /. This permissible current can be switched on at the same time by the overcurrent relay 8 during the rollover time Δ t . in this way, only the upper current peaks of rollovers, which go beyond the permitted power consumption / _ztl! be detected by the measurement.

The response time of the relay 8 can be kept short compared to the rollover period. she can but also deliberately set so that very small short flashovers that the electrostatic precipitator do not disturb, but rather promote, not be captured by the measurement.

An electricity meter 7 'can, for example, also use a current transformer in the form shown by dash-dotted lines 5 'must be switched into the direct current circuit of the electrostatic precipitator.

The area integral is thus used as the actual value for regulation in accordance with the method according to the main patent

b = J (II ₀ ) Ut

used.

F i g. 3 shows schematically the measured values obtained by the various counter circuits just described can be detected. The hatched areas show with

a = flat

the current consumption of the counter 7, which is switched on by the overcurrent relay 8 only during the rollover time J t .

b = J (II ₀ ) Ut

results, for example, from the measurement by means of an electricity meter T when this is connected to the direct current circuit of the E-filter 12 via a current transformer 5 ′.

c = / (/ - / _perm ) d /

would result if a second electricity meter 7 " in the opposite direction of rotation on the counter? would act, e.g. B. in the two-dot chain drawn circuit.

The switching device connected to the measuring mechanism shaft consists of a pointer 26, which is of a Spring 27 is pressed against an adjustable fixed stop 14. A pawl 15 engages in a ratchet wheel 21, which is firmly connected to the pointer 26. The pointer 26 is electrical depending on the position Contact with a busbar 28 or a busbar 29, or there is a gap between the two. This electrical contact closes an auxiliary circuit on which the drive motor 30 of the variable transformer lies. Depending on the position of the pointer on 28 or 29, the motor turns in one or other direction and thus a higher or. Caused lowering the tension. By adjustment of the resistors 24 connected upstream of the motor can correspond to the prevailing operating conditions the speed of rotation of the motor for one or the other direction of rotation is adjusted by hand will.

The use of a three-phase four-wire meter has the advantage that it is a component in the list only needs to be changed slightly in order to produce an embodiment according to the invention.

Instead, the commercially available overconsumption counters (subtraction counters) on register additional consumption above an adjustable load limit in a second meter, be used.

The load limit can be shifted by an externally adjustable multi-step gear. this can be done automatically by a slow measuring device, which only shows the mean effective value without short-term fluctuations in load due to filter breakdowns or slight drops in current as a result Brief increase in the internal resistance of the filter in the event of streaking in the gas.

Claims (4)

Patent claims: 1. A method for the automatic control of the voltage of an electrostatic dust collector, in which an interplay of voltage-increasing and voltage-reducing pulses acts on the variable transformer and in which, in addition to the number, the intensity of the flashovers is used to determine the voltage change, according to patent 1 080 979, characterized in that only the additional consumption of electricity or watt hours occurring in comparison to a permissible value (7 _perm ) due to the number and intensity of the flashovers occurring in the time unit serves as the actual value for the control. 2. The method according to claim 1, characterized in that only the electricity or watt-hour consumption the more violent flashovers occurring in the unit of time than the actual value for the control serves. 3. The method according to claims 1 or 2, characterized in that the measured variables for Actual value and target value are stored electrically and as storage capacitor counters to serve. 4. Device for performing the method according to one or more of claims 1 to 3, characterized in that for voltage regulation and for forming the difference between the actual and nominal value currents Serve transducers. Documents considered: German Auslegeschrift No. 1080 969. 1 sheet of drawings S »658/426 3.65 © Bundesdruckerei Berlin