RU2178885C2 - Apparatus for determining flash point of combustible liquids - Google Patents

Abstract

FIELD: systems for investigating organic liquids. SUBSTANCE: apparatus includes closed chamber having heater mounted in its wall, exhaust valve arranged on cover of chamber and having cylinder with ventilation openings and piston coaxial with cylinder. Pickup for detecting flash point includes high-voltage transformer, intermediate transformer, electric discharger. Signal divider, high frequency generator, counter and locking member are also units of flash point pickup. Apparatus also includes high-voltage pulse generator. Outlet of said generator is connected with terminals of primary winding of high voltage transformer, heater, temperature pickup, unit for indicating temperature. Outlet of said unit is connected with first control inlet of high-voltage pulse generator. EFFECT: enhanced reliability of apparatus. 1 dwg

Description

 The invention relates to devices for the study of organic liquids and can be used to determine the flash point of flammable liquids - various oils, petroleum products, etc.

 The device can also be used in chemical, petrochemical and other industries, as well as for research work to determine the flash point of flammable liquids in both open and closed crucibles.

 A device for determining the flash point of flammable liquids, containing an open crucible, a heating element, an ignition device, a temperature meter, a breakdown indicator made in the form of a series connection of a high voltage transformer winding, a control relay coil and a pair of electrodes located above the crucible [1].

 However, the known device has additional electrodes and a high voltage transformer, which complicates the design of the device. A high-voltage transformer, which is energized during the operating time of the device, reduces the safety of the measurement.

 Closest to the invention is a device for determining the flash point of flammable liquids, comprising a chamber with a heater installed in its walls, a cover with an exhaust valve made in the form of a cylinder with ventilation holes and a piston coaxial with it, a high-voltage transformer, a generator of high-voltage pulses, an electric spark gap, mounted above the level of the test fluid, a fluid temperature sensor, a flash sensor made in the form of a permanent magnet placed on the piston, and magnetically controlled contact located in the upper part of the cylinder [2].

 However, the known flash sensor does not allow to record the flash point of the liquid studied in an open crucible. The disadvantage of this device is the loss of physical properties of a permanent magnet during operation under the influence of high temperature.

 Installation on the camera cover of a second pair of electrodes, which is constantly under high voltage to fix the flash, is impossible for structural reasons (there is not enough space on the camera cover to install an additional pair of electrodes). For this reason, the flash lock described above [1] is not suitable for applying the flash point determination of flammable liquids in a closed crucible.

 The purpose of the invention is improving the reliability of determining flash points and expanding the scope.

 This goal is achieved by the fact that an intermediate transformer, a signal divider, a high-frequency generator, a counter and a locking element, which together with a high-voltage transformer and an electrode system are a flash sensor, are added to the device’s circuit, while one of the spark gap electrodes is connected to one of the secondary terminals windings of a high-voltage transformer, and the other electrode with its other output through the primary winding of an intermediate transformer, the signal divider has two inputs, one of which connected to the first output of the secondary winding of the intermediate transformer, and the second to the output of the high-frequency generator, the second output of the intermediate transformer is connected to a common point in the circuit, the counter input is connected to the output of the signal divider, and its output to the input of the gate element, whose output is the output of the sensor outbreaks.

 The drawing shows the design of the camera and a block diagram of the device.

 A device for determining the temperature of flammable liquids contains a closed chamber 1 with a heater 2 located in its walls, an exhaust valve located on the cover 3 of the chamber 1 and consisting of a cylinder 4 with ventilation holes 5 and a piston 6 coaxial with it, a high-voltage transformer 7, an intermediate transformer 8 , a high-voltage pulse generator 9 connected to the primary winding of the high-voltage transformer 7, a temperature sensor 10, a temperature display unit 11, the output of which 12 is connected to the control input 13 of the generator high-voltage pulses 9, a signal splitter 14 having two inputs, one of which is connected to a high-frequency generator 15, the other to one of the terminals of the secondary winding of the intermediate transformer 8, and its second output is connected to a common point of the circuit, counter 16, input which is connected to the output of the signal divider, and the output is connected to the input of the locking element 17, whose output is connected to the control inputs 18,19,20, high-voltage pulse generator 9, display unit 11, heater 21, respectively, an electric spark gap 22 Together with two electrodes, it forms an electrode system placed in the chamber 1 above the level of the test liquid 23, one of the electrodes of which is connected to one of the terminals of the secondary winding of the high voltage transformer 7, and the other electrode of the spark gap is connected to its other output through the primary winding of the intermediate transformer 8.

 The device operates as follows.

The test liquid 23 is heated to a temperature 10-15 ^° C below the expected flash point. The level of the signal from the temperature sensor 10, at this stage, is lower than the setting of the actuation of the temperature display unit 11, and therefore the high-voltage pulse generator 9 is blocked at the control input 13. The electric arrester is de-energized. The piston 6 is lowered - under the influence of gravity - to the base of the cylinder 4 and closes the exhaust hole 24 in the cover 3. Steam forms above the surface of the liquid.

 When the liquid reaches the temperature of the specified setting, the display unit 11 removes from its output 12 a signal blocking the generator 9. The device enters the measurement mode. Electric sparks periodically appear between the electrodes of the spark gap 22, and an electrical signal of the same frequency appears on the secondary winding of the intermediate transformer 8, but with a certain time duration, and at the output of the signal splitter 14, the number of pulses, the number of which is counted by counter 16, is immediately reset. However, in this mode, the number of pulses has such a value that the output of the locking element 17 does not block the operation of the high-voltage pulse generator 9.

 At a liquid temperature equal to the flash point, flammable gases that accumulate above the surface of the liquid flash under the influence of an electric discharge. In this case, the discharge time between the electrodes (due to the fact that the discharge occurs under other conditions) will change significantly. Consequently, the number of counted pulses at the counter output will be different than without a flash, and the locking element 17 will work, at the same time it will block the generator 9 at the control input 18, record the reading of the temperature display unit 11 on the board and turn off the power supply 21 at the control inputs 19 and 20, respectively . The pressure is triggered through the exhaust valve 24 and the ventilation holes 5. Reliability of fixing the flash temperature is ensured by the precise operation of the shut-off element and does not depend on the flash temperature.

 The described device can also be successfully used to determine the flash point of flammable liquids in an open crucible. In this case, from the circuit it is necessary to exclude the piston 6 mounted above the exhaust valve 24, of the chamber cover 3.

Sources of information
1. M. L. Goreltsev and L. M. Lifshits. A device for determining the flash point of flammable liquids // A. S. of the USSR 625153, class. G OI N 25/50, BI 35, 1978.

 2. Mikheev G. M., Antonov V. I. A device for determining the flash point of flammable liquids // USSR Patent 1806359 A, cl. GOIN 25/52, BI 12.1993, -2s. class G OI N 25/52.

Claims (1)

 A device for determining the flash point of flammable liquids, containing a chamber with a heater installed in its walls, a cover with an exhaust valve made in the form of a cylinder with ventilation holes and a piston coaxial with it, a high-voltage transformer, the primary winding of which is connected to a high-voltage pulse generator, and the secondary to an electric spark gap, a liquid temperature sensor connected to an indication unit, the output of which is connected to the first control input of the high-voltage pulse generator s, a flash sensor, the output of which is connected to the control input of the display unit, with the control input of the heater and with the second control input of the high-voltage pulse generator, characterized in that it further comprises an intermediate transformer, a signal divider, a high-frequency generator, a counter and a shut-off element, which together with the high-voltage transformer and the electrode system are flash sensors, while one of the electrodes of the arrester is connected to one of the terminals of the secondary winding of the high-voltage trans the formatter, and the other electrode with its other output through the primary winding of the intermediate transformer, the signal divider has two inputs, one of which is connected to the first output of the secondary winding of the intermediate transformer, and the second to the output of the high-frequency generator, the second output of the intermediate transformer is connected to the common point of the circuit, the counter input is connected to the output of the signal divider, and its output is connected to the input of the gate element, whose output is the output of the flash sensor.