Cooling liquid self-circulation double-mechanical-seal sand pump

Abstract

The utility model provides a cooling liquid circulation double mechanical seal sand pump, which relates to the field of oil and gas well drilling and comprises a main shaft, a mechanical seal pump cover and a sealing seat, the main shaft penetrates through the sealing seat and the mechanical seal pump cover, and an outer side mechanical seal device and an inner side mechanical seal device are respectively arranged on the mechanical seal pump cover and the sealing seat. An inner side mechanical seal moving ring with a pumping function is arranged between the outer side mechanical seal device and the inner side mechanical seal device, the inner side mechanical seal moving ring is fixed on the main shaft sleeve, the upper end and the lower end of the seal seat are respectively provided with a discharge interface and an access interface, the discharge interface is communicated right above the inner side mechanical seal moving ring, and the access interface is communicated right above the inner side mechanical seal moving ring. And the access interface is communicated with the lateral lower part of the inner side mechanical seal moving ring. By means of the pumping function, in the running process of the sand pump, pressure difference is generated at the position of a cooling liquid discharging connector and the position of a cooling liquid discharging connector, and therefore the cooling liquid can achieve a self-circulation loop, and the lubricating and cooling effects on a mechanical seal device are achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of oil and gas drilling, especially relates to a cooling liquid self-circulation double-mechanical seal sand pump. BACKGROUND

[0002] Sand pump is the most commonly used equipment for drilling fluid delivery in oil and gas drilling industry, and the mechanical seal device (referred to as: mechanical seal) used by the sand pump is a key component for sealing the liquid to be delivered, which forms a dynamic sealing pair between the friction end face of the hard alloy dynamic ring and the hard alloy static ring through the pre-pressure of the spring. Because the rotational speed of the sand pump is high, the relative linear velocity between the dynamic ring and the static ring is high, and the heat and wear caused by friction are also large. When the inlet of the pump is not filled with liquid into the pump body, the mechanical seal device lacking timely cooling is prone to high temperature and burning due to dry friction.

[0003] In recent years, double-mechanical seal sand pumps have appeared on the basis of traditional sand pumps. Commonly used is an integrated double-mechanical seal, which integrates two mechanical seals into one, and the spring is arranged in the middle to apply pre-tightening pressure to the dynamic rings of the two mechanical seals. After installation, the two seals form a cavity in the middle together with the mechanical seal pump cover and other parts, and cooling liquid or lubricating liquid is added in the cavity to cool and lubricate the friction pair of the mechanical seal. Due to the spring arrangement on the inside, when the sand pump is running, the pump pressure of the material chamber is too high, which is greater than the spring pressure, and the outside dynamic ring is pushed open, causing the two cavities to communicate and leak internally, and the material enters the middle cavity to mix with the lubricating cooling liquid and fail. Generally, the pump with this structure needs to pass compressed air into the lubricating and cooling circuit for pressurization to prevent internal leakage. This not only has a complex structure, but also has certain accident risks. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a cooling liquid self-circulation double-mechanical seal sand pump to solve the problems of poor cooling effect of the mechanical seal of the traditional sand pump, prolonging the service life of the mechanical seal, and pressure failure.

[0005] The utility model is implemented by the following technical scheme: a cooling liquid self-circulation double-mechanical seal sand pump, which comprises a main shaft, a mechanical seal pump cover and a sealing seat, the main shaft and the shaft sleeve pass through the mechanical seal pump cover and the sealing seat, the mechanical seal pump cover and the sealing seat are respectively provided with an outside mechanical seal device and an inside mechanical seal device, the inside dynamic ring of the inside mechanical seal device has a pumping function, the pumping ring and the inside dynamic ring of the inside mechanical seal device are designed as one whole, the sealing seat is respectively provided with a discharge interface and an access interface at the upper end and the lower end, the discharge interface is connected to the upper side of the pumping ring, and the access interface is connected to the lower side of the pumping ring. When the main shaft and the shaft sleeve and the pumping ring rotate, the discharge interface is in a high-pressure area, and the access interface is in a low-pressure area.

[0006] Further, the sealing seat and the main shaft form a stepped annular cavity, and the inner dynamic ring is installed in the annular cavity with a larger diameter.

[0007] Further, the access interface communicates with the annular cavity with a smaller diameter between the sealing seat and the main shaft, and the discharge interface communicates with the annular cavity with a larger diameter between the sealing seat and the main shaft, and the cavity is filled with cooling liquid; when the main shaft and the pumping ring rotate, the annular cavity with a larger diameter generates a liquid pressure higher than that of the annular cavity with a smaller diameter, thereby providing a dynamic pressure difference required for the self-circulation of the cooling liquid; when the inner dynamic ring rotates, the cooling liquid in the annular cavity with a larger diameter where the inner dynamic ring is located generates a pressure higher than that of the annular cavity with a smaller diameter due to the rotation of the pumping ring, thereby providing a dynamic force for the self-circulation of the cooling liquid.

[0008] Further, the outer mechanical seal device comprises a spring, a dynamic ring and a static ring, the dynamic ring is in contact with the static ring, the spring is arranged on one side of the dynamic ring, and the dynamic ring forms a dynamic sealing surface with the static ring under the pressure of the spring.

[0009] Further, the outer mechanical seal device is arranged in dynamic sealing between the mechanical seal pump cover and the main shaft and the shaft sleeve, the inner mechanical seal is arranged in dynamic sealing between the sealing seat and the main shaft and the shaft sleeve, and the annular cavity is located between the mechanical seal pump cover, the outer mechanical seal device, the sealing seat, and the inner mechanical seal device.

[0010] Further, the discharge interface and the access interface are connected with a cooling liquid bottle through pipelines respectively to form a cooling liquid circulation loop.

[0011] Further, a plurality of notches are formed in the pumping ring to improve the circulation efficiency of the cooling liquid.

[0012] The cooling liquid self-circulation double mechanical seal sand pump has the following beneficial effects.

[0013] The inner dynamic ring with the pumping function is arranged, so that a pressure difference is generated at the discharge interface and the exclusion interface of the cooling liquid during the operation of the sand pump, and kinetic energy is provided for the self-circulation of the cooling liquid. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings required in the following embodiment or prior art description will be briefly introduced, and the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained according to the structures shown in the drawings without creative labor for those skilled in the art.

[0015] Fig. 1It is a schematic view of a cooling liquid self-circulation double mechanical seal sand pump;

[0016] Fig. 2 It is a partial schematic view of the utility model;

[0017] Fig. 3 It is a schematic view of the appearance of the inner mechanical seal device;

[0018] In the drawing, 1-pump shell, 2-impeller, 3-main shaft, 4-mechanical seal pump cover, 5-outer mechanical seal device, 6-seal seat, 7-inner mechanical seal device, 8-shaft sleeve, 9-pump base, 51-spring, 52-outer dynamic ring, 53-outer static ring, 61-discharge interface, 62-connection interface, 71-inner dynamic ring, 72-inner static ring, 73-inner static ring seat, 74-spring group. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be described clearly and completely below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. The components of the embodiments of the utility model described and shown in the drawings can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the claimed utility model, but only represents selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the utility model.

[0021] As Figs. 1-3 shown, a cooling liquid self-circulation double mechanical seal sand pump, comprising pump shell 1, impeller 2, main shaft 3, mechanical seal pump cover 4, outer mechanical seal device 5, seal seat 6, inner mechanical seal device 7, shaft sleeve 8 and pump base 9.

[0022] The outer mechanical seal device 5 is located in the annular space formed by the impeller 2, the mechanical seal pump cover 4 and the seal seat 6, and the outer dynamic ring 52 and the outer static ring 53 of the mechanical seal device 5 form a dynamic sealing surface under the pressure action of the spring 51 and the inner mechanical seal device 7, which separates the annular space into a fluid material space and a lubricating cooling liquid cavity.

[0023] The upper end and the lower end of the seal seat 6 have a discharge interface 61 and a connection interface 62 of lubricating cooling liquid, which are connected with the corresponding interfaces of the outer hanging cooling liquid bottle respectively, and the lowest liquid level is higher than the corresponding interface of the discharge port.

[0024] The inner dynamic ring 71 is installed on the main shaft 3 and rotates with the main shaft 3 (the shaft sleeve 8), so that the lubricating cooling liquid near the inner dynamic ring 71 has higher local pressure than other positions, the lubricating cooling liquid with the local pressure is continuously sent out from the discharge interface 61, the cooling liquid in the externally hung cooling liquid bottle is supplemented into the cavity from the access interface 62, so that the lubricating cooling liquid realizes circulating flow, the heat generated by the friction pair of the outer dynamic ring 52 and the outer static ring 53 of the outer sealing device 5 is taken away, and the lubricating cooling effect on the outer sealing device 5 is achieved.

[0025] The inner dynamic ring 71 is in contact with the inner static ring 72, the spring group 74 is uniformly distributed on the other side end face of the inner static ring seat 73 and is pressed tightly, the inner static ring 72 forms a dynamic sealing surface with the inner dynamic ring 71 under the pressure of the spring 74, and the inner sealing device 7 is arranged at the tail of the sealing seat 6.

[0026] The inner dynamic ring 71 is located between the sealing seat 6 and the main shaft 3 (the shaft sleeve 8), and two communicating annular cavities are formed between the sealing seat 6 and the main shaft 3 (the shaft sleeve 8), the inner dynamic ring 71 is connected to a larger one of the two communicating annular cavities, the access interface 62 is connected to a smaller annular cavity, and the discharge interface 61 is connected to a larger annular cavity, when local high pressure is generated near the inner dynamic ring 71, in fact, local high pressure is generated in the larger annular cavity, and local low pressure is generated in the smaller annular cavity, so that the lubricating cooling liquid realizes circulating flow.

[0027] In the above embodiment, the basic principle and main features of the utility model and the advantages of the utility model are described. It should be understood by those skilled in the art that the utility model is not limited by the above embodiment, the above embodiment and the description in the specification are only to illustrate the principle of the utility model, and the changes and variations made by those skilled in the art without departing from the spirit and scope of the utility model should be within the protection scope of the claims of the utility model.

Claims

1. A self-circulating dual-pump sand screen with cooling fluid, characterized in that, The utility model relates to a kind of sealing device of pump, including main shaft (3) and shaft sleeve (8), machine seal pump cover (4) and sealing seat (6), main shaft (3) passes through machine seal pump cover (4) and sealing seat (6), the outer side machine seal device (5) and inner side machine seal device (7) are respectively installed on the machine seal pump cover (4) and sealing seat (6), the inner side machine seal device (7) between the outer side machine seal device (5) is provided with the inner dynamic ring (71) with pumping function, the inner dynamic ring (71) is fixed on main shaft (3), the sealing seat (6) upper and lower ends are provided with discharge interface (61) and access interface (62) respectively, the discharge interface (61) is communicated with the inner dynamic ring (71) directly above, the access interface (62) is communicated with the inner dynamic ring (71) side below, when main shaft (3), inner dynamic ring (71) rotates, discharge interface (61) is in high pressure area, and access interface (62) is in low pressure area.

2. The cooling liquid self-circulation dual-pump sand screen according to claim 1, characterized in that, Two annular cavities are formed between the sealing seat (6) and the main shaft (3), and the inner dynamic ring (71) is located in the larger one of the two annular cavities.

3. The cooling liquid self-circulation dual-pump sand screen according to claim 2, characterized in that, When the inner dynamic ring (71) rotates, the cooling liquid in the annular cavity where the inner dynamic ring (71) is located generates a higher pressure than in the other cavity, so that the cooling liquid generates a self-circulation power.

4. The self-circulating dual-pump sand screen of claim 1, wherein, The outer side machine seal device (5) includes a spring (51), an outer dynamic ring (52) and an outer static ring (53), the end face of the outer dynamic ring (52) is in contact with the outer static ring (53), the spring (51) is arranged on one side of the outer dynamic ring (52), and the outer dynamic ring (52) forms a dynamic sealing surface with the outer static ring (53) under the pressure action of the spring (51).

5. The self-circulating dual-pump sand screen of claim 1, wherein, The inner side machine seal device (7) includes an inner static ring (72), an inner dynamic ring (71), an inner static ring seat (73) and a spring group (74), the inner dynamic ring (71) is in contact with the inner static ring (72), the spring group (74) is uniformly distributed on the other side end face of the inner static ring seat (73) and presses it tightly, and the inner static ring (72) forms a dynamic sealing surface with the inner dynamic ring (71) under the pressure action of the spring group (74).

6. The self-circulating dual-pump sand screen of claim 2, wherein, The outer side machine seal device (5) is arranged between the machine seal pump cover (4) and the main shaft (3), the inner side machine seal device (7) is arranged between the sealing seat (6) and the main shaft (3), and the annular cavity is located between the machine seal pump cover (4), the main shaft (3), the sealing seat (6) and the inner side machine seal device (7).

7. The self-circulating dual-pump sand screen of claim 1, wherein, The discharge interface (61) and the access interface (62) are respectively connected to a cooling liquid bottle through a pipeline to form a cooling liquid circulation passage.

8. The self-circulating dual-pump sand screen of claim 1, wherein, A plurality of notches are formed in the inner dynamic ring (71) to improve the cooling liquid circulation efficiency.

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