CZ4177U1 - Counter for radial-type gas meters - Google Patents

Description

(54) Utility model name:

Counter for radial gas meters

CZ 4177 U

Counter for radial gas meters

Technical field

The technical solution concerns the engineering industry and electrical engineering, where the measuring part of the gas meter is mechanical and the evaluation, display and transmission part is electronic.

BACKGROUND OF THE INVENTION

Industrial gas meters are manufactured as mechanical meters of flow rate of gaseous medium with a roller counter. Remote transmission of flow rate data is ensured by separate sensors - transmitters, connectable to the gas meter, or by a reed contact, which senses the position of one roller of the meter of the meter. The built-in reed contact is not resistant to an external, intentionally created magnetic field, which can invalidate the data for remote transmission.

Calibration of the gas meter is performed by changing the gear ratio of the gas meter counter gear or by changing the dimensions and position of the turbine rings.

The cylindrical counter with the transmission system has a mechanical resistance which causes a decrease in the overall accuracy and stability of the gas meter. The essence of the technical solution

The technical solution consists in replacing the mechanical counter with the sensors with an electronic counter. This eliminates many of the disadvantages of a mechanical measuring system.

A magnet is mounted in the turbine of the radial gas meter which, when the turbine rotates under the influence of the flowing medium, generates an alternating magnetic field proportional to the speed. This field is sensed by a magnetic transducer from which pulses come to the electronic counter circuits. Calibration of the gas meter is done by setting the dividing ratio of the electronic divider according to the calculation or from the tables.

The advantage of electronic control over mechanical control is in simplicity, accuracy, speed and stability. Remote data transmitters are electronic, resistant to the effects of magnetic fields.

Overview of pictures

The attached drawing - Fig. 1 shows a block diagram of an electronic counter of a radial gas meter.

Examples

Fig. 1 is a block diagram of an electronic counter showing the direction of the pulse signals. The voltage pulses from the output of the magnetic sensor 1 are processed by the electronic counter circuitry 2, which adjusts the shape of the pulse signals, their length of 4177 U ku, multiples of pulses, pulse splitting and ensures communication with other circuits.

Calibration of the radial gas meter is done by setting the code of the two-pole switches in the preset divider χ by calculation or from tables. The table shows the ratio between the calibration correction value and the combination of preset divider switches.

By setting the correct switch combination, the electronic counter circuitry X, which further controls the LCD display 4, shows the total flow of gaseous medium.

In addition, the electronic counter 2 controls two pulse transmitters for remote transmission, the NAMUR 5 transmitter and the open collector 6 transmitter. to DIN 19 234 - NAMUR. This transmitter is usually used to measure the instantaneous flow of the medium. The open collector 6 transmitter transmits increments of several orders of magnitude larger than the NAMUR transmitter (eg 1000 L), and thus normally copies the LCD display condition. This transmitter is typically used for remote indication and registration of the total flow rate of gaseous medium, and for volume correction in gas conversion devices. Both transmitters are galvanically separated by an optical element from the electronic counter circuits

2. The sensor χ is placed in a magnetically conductive metal housing, which ensures the resistance of the sensor to the external magnetic field, and thus the gas meter cannot be influenced.

The electronic counter circuits with peripherals are supplied from the power supply module 7 with protection components against accidental failure (short circuit in the electronics).

Industrial applicability

Radial turbine gas meters are used to accurately measure the flow rate of natural gas, town gas, propane-butane, air and other gaseous media. They are suitable as a measuring instrument for payments, industrial measurement and energy balance.

Claims (1)

PROTECTION REQUIREMENTS Counter for radial gas meters, displaying and emitting total flow of gas, characterized in that it consists of a sensor (1) with a magnetically conductive metal cover, electronic counter circuits (2), a preset divider (3) with code setting switches during calibration , LCD displays (4), NAMUR transmitters (5), open collector transmitters (6), and power supply module (7) with protective components.