CN-224201500-U - Liquid ammonia tank field instrument air supplementing device during overhaul

Abstract

The utility model relates to an instrument air supplementing device for a liquid ammonia tank area during overhaul, which comprises an instrument air storage tank, an external network main pipe and a downstream air supply pipeline, wherein the external network main pipe and the downstream air supply pipeline are connected with the instrument air storage tank, a pressure gauge and an air distribution tank are sequentially arranged on the downstream air supply pipeline, the air distribution tank is connected with a user end, the instrument air supplementing device further comprises a nitrogen cylinder group and a storage platform, a first stop valve, a check valve and an air supplementing channel are sequentially arranged on the external network main pipe along the air inlet direction, one end of the air supplementing channel is connected into the external network main pipe through a second stop valve, and the other end of the air supplementing channel is connected with the nitrogen cylinder group. By adding a stop valve, a check valve and an air supplementing channel on the main pipe of the boundary region, the nitrogen cylinder group can be timely accessed under the abnormal condition during annual maintenance, and instrument air can be timely supplemented as an alternative scheme. The mode can not only meet the requirement of instrument air supply of a small-scale device, but also avoid automatic opening of the pneumatic regulating valve of the liquid ammonia storage tank due to pressure loss, ensure environmental protection and safety, and have higher flexibility without changing the distribution and trend of the original pipeline.

Inventors

• TAO LEI
• ZHOU JIAN
• CHEN BING
• ZHU KAIJIN

Assignees

• 实联化工(江苏)有限公司

Dates

Publication Date

20260505

Application Date

20250604

Claims (5)

1. 1. The utility model provides a liquid ammonia tank field instrument air replenishing device during overhaul, includes instrument air storage tank (7) and outer net house steward (8) and downstream air feed pipeline (9) that link to each other with it, be provided with manometer (10) and gas separation jar (11) on the downstream air feed pipeline (9) in proper order, gas separation jar (11) link to each other with user's end (12), its characterized in that still includes nitrogen cylinder group (1) and is used for placing storage platform (13) of nitrogen cylinder group (1); The external network main pipe (8) is sequentially provided with a first stop valve (5), a check valve (4) and an air supplementing channel (3) along the air inlet direction, one end of the air supplementing channel (3) is connected into the external network main pipe (8) through a second stop valve (6), and the other end of the air supplementing channel (3) is connected with the nitrogen cylinder group (1).
2. 2. A liquid ammonia tank farm instrument air replenishment device during overhaul according to claim 1, characterised in that the nitrogen cylinder group (1) consists of several cylinders of nitrogen.
3. 3. The instrument air supplementing device for the liquid ammonia tank farm during overhaul according to claim 1, wherein the air supplementing channel (3) is a pressure-resistant hose, and a pressure reducing valve (2) is arranged at the joint of the nitrogen cylinder group (1) and the air supplementing channel (3).
4. 4. The instrument air supplementing device for the liquid ammonia tank farm during overhaul according to claim 1, wherein a safety valve (14) is externally connected to the instrument air storage tank (7).
5. 5. A liquid ammonia tank farm instrument air replenishment device according to claim 1, wherein the customer premises (12) is provided with an oxygen detector (15).

Description

Liquid ammonia tank field instrument air supplementing device during overhaul Technical Field The utility model relates to the field of chemical production devices, in particular to an instrument air supplementing device for a liquid ammonia tank area during overhaul. Background The liquid ammonia storage tank is a key storage device in the fields of chemical industry, refrigeration and the like and is used for maintaining production continuity, and the safe operation of the liquid ammonia storage tank depends on accurate control of an instrument air system on a pneumatic regulating valve. Under the conventional working condition, instrument air is supplied by an air compressor or an air separation device, but during the annual overhaul period, the air separation device is required to be shut down for maintenance, an enterprise is usually switched to a standby oil-free screw compressor to serve as a temporary air source, and meanwhile, a certain amount of liquid ammonia is still required to be stored for driving according to design requirements. However, the overhaul period is long, the overhaul project is complex, and the temporary air source is easy to suddenly lose pressure due to the problems of equipment aging, load fluctuation and the like, so that the air pressure of the instrument is suddenly reduced. In the prior art, the standby oil-free screw compressor is adopted as a temporary air source, and the obvious defect is that the temporary air source is generally far away from an air source point in a tank field due to consideration of supply of the temporary air source in the period annual maintenance, the air supply stability is possibly insufficient in long-distance transportation in the overhauling period, and the long-time requirement in the overhauling period is difficult to match. Secondly, the traditional gas storage tank has limited capacity and short buffering time, and cannot cover the rush-repair period of sudden voltage loss. And thirdly, when sudden pressure loss occurs, the pneumatic regulating valve of the liquid ammonia storage tank is automatically switched to an open state based on a design principle of fault-safety so as to avoid overpressure explosion of the storage tank, but the action can cause leakage of liquid ammonia, thereby causing atmospheric pollution and safety risk. Disclosure of utility model Aiming at the problem that a standby oil-free screw compressor is used as a temporary air source during overhaul to easily cause sudden instrument air pressure loss and generate ammonia leakage in the prior art, the utility model provides an instrument air supplementing device for a liquid ammonia tank area during overhaul, which comprises an instrument air storage tank, an external net main pipe and a downstream air supply pipeline, wherein the external net main pipe and the downstream air supply pipeline are connected with the instrument air storage tank; The external network main pipe is sequentially provided with a first stop valve, a check valve and an air supplementing channel along the air inlet direction, one end of the air supplementing channel is connected into the external network main pipe through a second stop valve, and the other end of the air supplementing channel is connected with the nitrogen cylinder group. Further, the nitrogen cylinder group consists of a plurality of cylinders of nitrogen. Furthermore, the air supplementing channel is a pressure-resistant hose, and a pressure reducing valve is arranged at the joint of the nitrogen cylinder group and the air supplementing channel. Further, a safety valve is externally connected to the instrument air storage tank. Further, the user side is provided with an oxygen detector. Compared with the prior art, the utility model has the following beneficial effects: By adding a stop valve, a check valve and an air supplementing channel on the main pipe of the boundary region, the nitrogen cylinder group can be timely accessed under the abnormal condition during annual maintenance, and instrument air can be timely supplemented as an alternative scheme. The instrument air supply of the small-scale device can be met by the mode, the automatic opening of the pneumatic regulating valve of the liquid ammonia storage tank due to the pressure loss is avoided, the environment protection safety is ensured, the distribution and trend of the pipeline of the external network main pipe are not required to be changed, the operation is convenient and fast in a mode of manually connecting an external air supplementing channel, and the device has higher flexibility. Drawings FIG. 1 is a schematic diagram of the overall structure of the present utility model; In the figure, 1, a nitrogen cylinder group, 2, a pressure reducing valve, 3, an air supplementing channel, 4, a check valve, 5, a first stop valve, 6, a second stop valve, 7, an instrument air storage tank, 8, an external net main pipe, 9, a downstream air supply pipeline, 10, a pres