CN202268113U - Constant-pressure meter - Google Patents

Abstract

The utility model belongs to laboratory instruments, in particular to an isobarometer used for a liquid saturated vapor pressure measuring device. The isobarometer comprises a first vertical pipe (21), a second vertical pipe (22), and a third vertical pipe (23). pipe (24), the second vertical pipe (22) and the third vertical pipe (23) are connected by a second elbow (25), and the pipe diameter at the top of the second elbow (25) is smaller than that of the first The pipe diameter of the other parts of the two elbows (25), the middle part of the second elbow (25) is a trumpet-like structure (27) that is small in the middle and two ends are big. The utility model has the advantages of simple structure and convenient operation, and can reduce the probability of backflow phenomenon of the isobarometer.

Description

Isobarometer

technical field

The utility model belongs to laboratory instruments, in particular to an isobarometer used for a liquid saturated vapor pressure measuring device.

Background technique

The saturated vapor pressure of a pure substance refers to the pressure of the vapor when the gas-liquid two phases are in equilibrium at a certain temperature. The device for measuring the saturated vapor pressure of a liquid in the laboratory includes a constant temperature tank, a numerical pressure gauge, and an air pump. An isobarometer is installed in the constant temperature tank. The upper end of the isobarometer is connected to a condensing pipe, and the condensing pipe is connected to the numerical pressure gauge and the air pump through a conduit. The isobarometer in the prior art is as shown in Figure 1, comprises the first standpipe (21), the second standpipe (22), the 3rd standpipe (23), the first standpipe (21) and the second standpipe The pipes (22) are connected through a first elbow (24), and the second vertical pipe (22) and the third vertical pipe (23) are connected through a second elbow (25). During the experiment, earlier ethanol (26) is added in the isobaric gauge, respectively stay one section ethanol (26) in the 3rd standpipe (23) and the first elbow (24), guarantee the 3rd standpipe (23) and The space between the first elbow (24) has only ethanol (26) vapor. If the left and right liquid levels of ethanol (26) at the first elbow (24) place are equal, then the saturated vapor pressure of ethanol (26) between the third vertical pipe (23) and the first elbow (24) is the same as that of the first The pressure above the ethanol (26) in the vertical pipe (21) is equal, and the pressure above the ethanol (26) in the first vertical pipe (21) can be measured by a numerical pressure gauge, and the measured value is the saturation of the ethanol (26). Vapor Pressure. The liquid level of ethanol (26) left and right at the first elbow (24) place needs to be regulated by the air supply of the air pump. When the students are in the experiment, due to the poor control of the air supply speed of the air pump, the ethanol (26) of the first elbow (24) ) is easily washed into the third standpipe (23) so as to merge with the ethanol (26) of the third standpipe (23), causing the failure of the experiment. This phenomenon is commonly known as backflow. After backflow occurs, the isobaric gauge needs to be taken off to make the ethanol (26) be divided into two sections again, which is troublesome to operate. If the isobaric gauge itself is in a heated state in the constant temperature bath, it will be even more cumbersome to handle.

Utility model content

The purpose of the utility model is to provide an isobaric gauge which reduces the occurrence probability of backflow phenomenon.

The solution of the utility model to solve the technical problem is: an isobaric gauge, comprising a first vertical pipe, a second vertical pipe, and a third vertical pipe, and the first vertical pipe and the second vertical pipe pass through a first bend connection, the second vertical pipe and the third vertical pipe are connected through a second elbow, the diameter at the top of the second elbow is smaller than the diameter of other parts of the second elbow, and the middle part of the second elbow is A trumpet-shaped structure with a small middle and two large ends.

When students are operating, once the air supply speed of the air pump is too fast, the liquid at the first elbow will be pressed to the second elbow by pressure, because the diameter of the top of the second elbow is smaller than the other parts of the second elbow The middle part of the second elbow is a horn-shaped structure with a small middle and two big ends. The liquid that is pressed to the second elbow is not easy to pass through the top of the second elbow with a smaller diameter, which reduces the phenomenon of backflow. probability. In case some liquid passes through the top of the smaller pipe diameter, the experiment can continue because the liquid at the first bend has not completely mixed with the liquid at the third vertical pipe.

As a further technical solution, a branch pipe is provided between the trumpet-shaped structure and the second vertical pipe.

Since the branch pipe is set between the trumpet-shaped structure and the second vertical pipe, the liquid that is pressed to the top of the second pipe will follow the branch pipe to the second vertical pipe and then return to the first pipe, further reducing the possibility of backflow. probability.

The utility model has the advantages of simple structure and convenient operation, and can reduce the probability of backflow phenomenon of the isobarometer.

Description of drawings

Fig. 1 is the structural representation of pressure gauge in the prior art;

Fig. 2 is a structural representation of the utility model;

Fig. 3 is a schematic diagram of the utility model in use.

Detailed ways

As shown in Figure 2, a kind of isobaric gauge comprises a first vertical pipe 21, a second vertical pipe 22, and a third vertical pipe 23, and a first elbow 24 is passed between the first vertical pipe 21 and the second vertical pipe 22. Connection, the second vertical pipe 22 and the third vertical pipe 23 are connected by the second elbow 25, the pipe diameter at the top of the second elbow 25 is smaller than the pipe diameter of the other parts of the second elbow 25, the second elbow The middle part of 25 is a horn-shaped structure 27 with a small middle and two big ends, and a branch pipe 28 is arranged between the horn-shaped structure 27 and the second vertical pipe 22 .

When the isobarometer is in use, as shown in Figure 3, the entire device including the isobarometer is called a liquid saturated vapor pressure measuring device, and the liquid saturated vapor pressure measuring device also includes a constant temperature tank 1, a numerical pressure gauge 3 and an air pump 4. An isobarometer, a thermometer 6 and an agitator 7 are arranged in the constant temperature tank 1, and the upper end of the first standpipe 21 of the isobarometer is connected to the condensing pipe 5, and the condensing pipe 5 communicates with the numerical pressure gauge 3 and the air pump 4 through the conduit 8.

Claims (2)

1. an equipressure is counted; Comprise first vertical tube (21), second vertical tube (22), the 3rd vertical tube (23); Be connected through first bend pipe (24) between first vertical tube (21) and second vertical tube (22); Be connected through second bend pipe (25) between second vertical tube (22) and the 3rd vertical tube (23), it is characterized in that: the caliber of the top end of said second bend pipe (25) is less than the caliber of other parts of second bend pipe (25), the big horn-like structure (27) in little two in the middle of the middle part of second bend pipe (25) is.

2. a kind of isobaric meter as claimed in claim 1 is characterized in that: between said horn-like structure (27) and second vertical tube (22) arm (28) is set.

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