RU2402044C1 - Pneumatic source of seismic signals - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: pneumatic source of seismic signals has cylindrical housing made in the form of thick-wall tube, which contains inlet and outlet compressed air channel, high pressure accumulation chamber, damping and control chambers. Into the latter there placed is activation sensor located in its upper zone, stock moved and passing through the above chambers and having the inner channel connecting the control chamber to HP accumulation chamber, and three pistons: lower one which is made as per valve type, which covers the exhaust hole in edge zone of lower part of housing, middle one and upper one made from magnetic material. Upper piston divides control and damping chambers, and middle one divides damping and accumulation ones. Working areas of pistons follow the following ratio: S_work.l.<S_work.mid., where S_work.l - working area of lower piston, S_work.mid. - working area of middle piston. In central part of damping chamber there is partition with magnetic element attracting the upper piston, and having through channel connecting upper and lower parts of damping chamber.

EFFECT: reaching smooth operation of device at decrease of actuation time, and decreasing the value of spread of this time.

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Description

The invention relates to seismic exploration and can be used in devices for generating seismic waves.

Numerous devices for generating seismic energy are currently known, for example:

"Pneumatic source of seismic signals [SU copyright certificate for invention No. 10556102],

"Pneumatic generator of elastic signals" [SU copyright certificate for invention No. 1045184],

"Source for marine seismic exploration" [SU copyright certificate for invention No. 17878722],

"Pneumatic source of seismic signals" [RU patent for utility model No. 80964] and others.

Common signs of pneumatic sources are the presence of a housing with a movable cylinder, a fixed rod with pistons, sealing elements, a pneumatic line with valves controlling and working pneumatic chambers, the flow of compressed air from which creates pulses of elastic energy.

Common shortcomings of the aforementioned pneumatic sources are the long sizes of the sealing elements and, as a result, the insufficient reliability of the sealing of the elements of the devices, as well as the contacting of the moving elements of the devices with the external environment and the possibility of their pollution.

Technical solutions are also known in which the movable element is a rod, and the body and its cylindrical elements are stationary: a source of seismic waves [US patent No. 3653460], air gun [US patent No. 4047591], air source of seismic signals [copyright certificate SU No. 1625220], seismic air emitter [RU patent for invention No. 2204848], downhole source of seismic signals [RU patent for invention No. 2240581] and others.

These devices include a housing with exhaust windows, a movable rod with pistons, control and accumulation chambers, sealing elements, a pneumatic line with valves.

The disadvantages of these devices include insufficiently short response time.

The closest analogue to the claimed device is a pneumatic source of seismic signals [copyright certificate SU No. 548815]. It contains a cylindrical body, sealing elements, pneumatic lines, a rod with three pistons, chambers for accumulating compressed gas and controlling the operation of the device, an exhaust window and an electromagnet. The operation of the device occurs when the electromagnet is turned on, which attracts the rod and moves it from its place.

The disadvantage of this device is the inability to smoothly brake the rod after the device is triggered, as well as the insufficiently fast response of the source, which leads to a spread in the duration of the response time and makes it impossible for a pneumatic source to emit high-frequency seismic signals.

The objective of the invention is to achieve smooth operation of the device while reducing response time and reducing the magnitude of the dispersion of this time.

The essence of the claimed invention is characterized in that the pneumatic source of seismic signals has a cylindrical body in the form of a thick-walled pipe containing an inlet and outlet channel of compressed gas, a high-pressure storage chamber, a damper and a control chamber with an actuation sensor located in the latter located in its upper zone, which can be moved and a rod passing through the aforementioned chambers with an internal channel in it connecting the control and accumulation chambers with high pressure and three pistons: it is made according to the type of valve that covers the exhaust hole in the boundary zone of the lower part of the housing, the middle and upper are made of magnetic material, while the upper piston separates the control and damper chambers, and the middle piston separates the damper and accumulator, and the working areas of the pistons are subject to the following ratio :

S _work <S _{working time} ,

where S _slave - working area of the lower piston,

S _Sat. - working area of the middle piston;

in the central part of the damper chamber, a partition is made with a magnetic element attracting the upper piston and having a through channel connecting the upper and lower parts of the damper chamber.

The technical result consists in solving the problem with those technical means and techniques that are described below in the description. The composition of all nodes and parts included in the inventive device is new, thanks to it, the result of effective operation is achieved and the above-described disadvantages of existing analogs are eliminated, including the closest one, namely, a damper unit in the form of a damper chamber located between the storage chamber is introduced into the pneumatic source of seismic signals and camera control. From diametrically opposite sides vertically at the ends of the damper chamber are placed pistons. In the central part of the damper chamber, a partition is made with an opening for the passage of the rod. In the body of the partition are vertically elongated channels connecting the parts of the damper chamber above and below the partition. In the baffle of the damper chamber there is a magnetic element capable of attracting the upper piston. The partition is rigidly fixed to the inner surface of the housing and therefore does not move.

The drawing shows the claimed pneumatic source of seismic signals with the corresponding nodes and parts indicated by numbers:

1 - cylindrical body;

2 - stock;

3 - magnet sensor response;

4 - the upper piston;

5 - the middle piston;

6 - the lower piston;

7 - sealing elements;

8 - storage camera;

9 - an exhaust opening;

10 - control camera;

11 - inductor;

12 - non-magnetic conductive frame;

13 - load-bearing armored cable;

14 - pneumatic line;

15 - hole control camera;

16 - damper chamber;

17 - a partition;

18 - channel;

19 - liquid;

20 - a magnetic element;

21 - an internal magnetic circuit;

22 - external magnetic circuit;

23 - ring;

24 - channel located in the stock;

25 - shutoff valve;

26 - closed valve;

27 - valve;

28 - discharge line;

29 - pressure seal.

The pneumatic source of seismic signals contains a cylindrical body 1 made of a thick-walled pipe. Inside the housing 1 there is a rod 2 with a permanent magnet 3 located on its upper part, which is part of the pickup sensor, and the upper, middle and lower pistons 4, 5, 6, equipped with sealing elements 7. The working area of the lower piston 6 is less than the average working area piston 5. The lower piston 6 is made as a valve.

In the boundary zone of the lower part of the housing 1 there is a high-pressure storage chamber 8 and an exhaust outlet 9 blocked by the lower piston 6. In the upper part of the housing there is a control chamber 10, in which the inductance coil 11, which is a second part of the operation sensor, is wound around a non-magnetic conductive frame 12 mechanically and electrically connected to the housing 1. An inductance coil is electrically connected to the frame by one pole and the armored conductive insulated residential conductor with the second cable 13, passed inside the pneumatic line 14, and communicating with the control chamber 10 with the hole 15, which serves as the input and output channel of the compressed gas. In this case, the armor of the load-carrying cable is mechanically and electrically connected with the housing 1.

Between the storage chamber 8 and the control chamber 10, there is a damper chamber 16, divided by a partition 17 into lower and upper parts, which communicate with each other through a channel 18 formed by the gap between the rod 2 and the hole in the partition 17. The lower compartment of the damper chamber may be partially filled with liquid 19 to increase resistance to overflow through the channel 18. The partition 17 is mechanically connected to the housing 1 and includes a magnetic element in the form of a permanent magnet 20 of cylindrical shape with radial magnetization , the inner 21 and outer 22 magnetic cores are also cylindrical in shape and a ring 23 made of a strong non-magnetic material, such as a titanium alloy, which serves to increase the strength of the device. The partition 17 is a fixed element of the magnetic system, and the piston 4, made of ferromagnetic material and in contact with the partition 17 in the initial position due to the forces of magnetic attraction, plays the role of the movable element.

The working chamber 8 and the control chamber 10 communicate with each other through a through channel 24 passing inside the rod 2. The through channel 24 in the working chamber 8 is closed by a shut-off valve 25, which is capable of passing compressed gas only in one direction from the control chamber 10 to the working chamber 8.

The pneumatic line 14 and the electrical communication line in the form of an armored cable 13 connected at one end to the housing 1, the second end are connected to the control panel containing a normally closed valve 26 connecting the pneumatic line 14 with a compressor (not shown), a valve 27 connecting the pneumatic line 14 with discharge line 28 and pressure seal 29, through which the electrical communication line is connected to the seismic station.

The operation of the claimed device is as follows.

In the initial position, the rod 2 is in its lowest position. In this case, the piston 6 hermetically closes the exhaust outlet 9, and the piston 4 is tightly pressed against the magnet 20 of the partition 17. To prepare the device for operation along the pneumatic line 15, gas is supplied under pressure to the control chamber 10. Compressed gas fills the control chamber 10 and flows through the channel 24 located in the rod 2 into the storage chamber 8 through the shut-off valve 25. As a result, the gas pressure in the chambers 8 and 10 is equalized and reaches the operating value. So that at the working pressure of the gas the rod 2 was stationary, the area of the pistons are selected as follows:

S _pa.b. <S _Sat. ,

where S _slave - working area of the lower piston 6,

S _Sat. - the working area of the middle piston 5.

In order for the device to work, open the valve 27 and thereby connect the pneumatic line 15 to the gas discharge line. The gas pressure in the control chamber 10 drops. Due to the difference in the working areas of the pistons 5 and 6, upward force acts on the stem. When this force becomes greater than the force of mutual attraction of the magnet 20 and the piston 4 and the force of the residual gas pressure in the control chamber to the piston 4, the rod begins to move upward, while the piston 6 releases the window 9, through which a sharp release of compressed gas into the surrounding space occurs.

The force of attraction between the magnet 20 and the piston 4 drops sharply with an increase in the gap between them, which contributes to a sharper opening of the exhaust opening 9.

Further, when the rod 2 moves upward, gas and liquid of the damper chamber flow along the channel 18 from its lower part to the upper one, which leads to smooth braking and stop of the rod 2.

When the permanent magnet 3, located in the upper part of the rod 2, approaches the inductor 11, the induction emf is induced in the latter, and a current pulse is transmitted via cable 13 to the control panel, signaling the operation of the device.

To bring the device to its initial state, compressed gas is again supplied to the control chamber 10, under the action of which the piston 4 moves down together with the rod 2 until it contacts the magnet 20.

The placement of the magnetic element in the inventive device, in contrast to its closest analogue, provides the opposite effect - holding the rod in its original position and the device as a whole from being triggered, while in the closest device the rod is attracted through an intermediate telescopic assembly to ensure the operation of the compared device. In addition, the presence of a response sensor in the upper zone of the control chamber distinguishes the claimed device from the closest analogue.

Example. The inventive pneumatic source of seismic signals was made at the enterprise of the city of Saratov in the form of a prototype, it was successfully tested.

Claims (1)

A pneumatic source of seismic signals, characterized in that it has a cylindrical body in the form of a thick-walled pipe, containing inlet and outlet channels of compressed gas, a high-pressure storage chamber, a damper and a control chamber with an actuation sensor located in the latter, located in its upper zone, movable and a rod passing through the aforementioned chambers with an internal channel connecting it to the control and storage high-pressure chambers and three pistons: the lower one, made according to the type of valve a panel that covers the exhaust hole in the boundary zone of the lower part of the housing, the middle and upper, made of magnetic material, while the upper piston separates the control and damper chambers, and the middle - the damper and accumulator, and the working areas of the pistons are subject to the following ratio:
S _work <S _{working time} ,
where S _pa - working area of the lower piston,
S _work - working area of the middle piston;
in the central part of the damper chamber, a partition is made with a magnetic element attracting the upper piston and having a through channel connecting the upper and lower parts of the damper chamber.