A sealing repair method for POC dry gas holder

Abstract

The present invention belongs to the technical field of gas holder maintenance in enterprises such as metallurgy and petrochemical industry, and specifically relates to a method for repairing the seal of a POC dry gas holder. After the gas holder stops operating and the piston lands, all the sealing oil is drained. The compensation demand is calculated, and then the sealing overlap point is adjusted. The compensation amount is symmetrically adjusted at the sealing connection point to reduce the circumferential tension and improve the fitting amount of the rubber block and the side plate, indirectly achieving radial compensation. In view of the actual wear amount of the rubber block, the present invention adds rubber blocks with appropriate lengths to local positions, which neither increases the tension in other parts nor eliminates the circumferential tension of the rubber block, achieving the purpose of extending the service life of the rubber block.

Description

Technical Field

[0001] The present invention belongs to the technical field of the repair of gas holders in metallurgical, petrochemical and other enterprises, and specifically relates to a method for repairing the seal of a POC dry gas holder. Background Art

[0002] The piston seal rubber of the POC dry gas holder adopts reinforced nitrile rubber. Its working principle is as follows: As the gas production and consumption change, the piston moves up and down. A sealing device is arranged in the oil groove around the steel piston. The sealing rubber part adopts reinforced nitrile rubber. During the movement process, it fits with the cabinet wall through the sealing rubber and fills about 1.8 meters deep sealing oil. Through the lever counterweight force application mechanism, it is closely attached to the cylindrical cabinet body to reduce the leakage amount of the sealing oil, thereby ensuring that the gas does not leak during the movement of the piston. At the same time, the height of the sealing oil is measured by a piston oil groove liquid level detector to ensure the safety of the piston seal system. The sealing oil slowly flows down along the inner wall of the side plate through the extremely small gap between the side plate of the cabinet body and the sealing rubber in the piston oil groove and enters the bottom oil groove of the gas holder. The sealing oil in the bottom oil groove enters the oil pump station through a pipeline. After oil-water separation, the sealing oil is pumped into the reserve oil tank located in the upper part of the gas holder through an oil riser pipe, and then flows out through the overflow hole of the reserve oil tank and flows into the piston oil groove along the inner wall of the side plate, thus forming a circulating supply system for the sealing oil.

[0003] When the seal of the gas holder wears to a certain extent, it will cause uneven stress on the piston seal rubber of the gas holder, resulting in its damage or an increase in the oil leakage amount, causing the sealing oil level to drop rapidly. When it drops to a certain extent and the oil level pressure is lower than the gas pressure, gas leakage accidents will occur after the gas pressure breaks through the piston seal oil groove of the gas holder.

[0004] The gas holder is a major hazard source. The sealing rubber blocks are at the bottom of the 1.8-meter-deep oil groove and run reciprocally in the 98-meter-high gas holder for a long time. The rubber blocks slide and rub against the gas holder wall, and they are all replaced after wear. Due to the adjustment of the operation mode, the wear of the rubber blocks is aggravated. Analysis of the rubber blocks removed in the early stage shows that the wear amount reaches about 50% of the design value, but the sealing effect can no longer meet the sealing requirements. In order to eliminate potential hazards, the measure of replacing the sealing rubber blocks has always been taken. The rubber blocks around the 300,000-cubic-meter gas holder have a diameter of 63 meters. After being connected, the total length is about 198 meters. There are a total of 5 layers of sealing rubber blocks, and all 160 rubber blocks are replaced. First, 280 tons of sealing oil are discharged, and the sludge in the oil groove with a length of 198 meters and a width of 0.3 - 0.4 meters is cleaned. Secondly, 730 sets of sealing rubber pressing devices, including wire ropes, pressing T-shaped irons, alder wood, etc., are gradually disassembled, and the sealing blocks are disassembled section by section. Finally, each sealing block is installed and the pressing device is adjusted. The replacement construction period is long and the maintenance cost is high.

[0005] The total length of the sealing rubber blocks of the thin oil tank is 198 meters, and there are 165 rubber blocks in 5 layers. After wear, the conventional method is to replace them, and there was no previous repair case. Summary of the Invention

[0006] The object of the present invention is to: extend the operation cycle of the gas holder and reduce the maintenance cost. After the lean oil gas holder operates to a certain stage, a sealing repair method is provided to restore the sealing requirement. By measuring the wear amount, the seal is adjusted and appropriately compensated to extend the sealing life of the gas holder.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A method for repairing the seal of a POC dry gas holder. The gas holder stops operating. After the piston lands, all the sealing oil is drained. The compensation requirement is calculated, and then the seal overlap point is adjusted. The compensation amount is symmetrically adjusted at the seal connection point to reduce the circumferential tension and improve the fitting amount of the rubber block and the side plate, indirectly realizing radial compensation.

[0009] The features of the present invention also include:

[0010] After the sealing oil of the gas holder is drained, the wear amount of the rubber block is measured, and the remaining service life is calculated according to the operation cycle. When the remaining amount exceeds 50%, compensation measures are taken for the rubber block.

[0011] The specific operation steps are as follows: First step: Cut each section of the sealing block between the columns and observe the springback amount of the cut. When the springback amount exceeds 1 cm, synchronously cut the other four sections, and naturally fill the compensation block; Second step: Cut the rubber blocks on both sides of the cutting point in the first step respectively, measure the springback amount of the cut, and increase the filling amount by 1-5 mm wider than the cut to appropriately compensate the cutting point in the first step, and fill to achieve overall free compensation; Third step: Adjust each compensation block to be flat and press it tightly with an angle steel to prevent it from falling off or shrinking towards the piston side; Fourth step: Adjust the weight of the pressing device; Fifth step: Adjust the remaining three sections according to the first four steps, and the adjustment amount is increased according to the actual compensation; Sixth step: Inject oil and supply gas, raise the piston, observe the starting frequency of the oil pump, and adjust the pressing device until it reaches the best state.

[0012] Further preferably, in the second step, the increased filling amount is 1-3 mm wider than the cut; more preferably, in the second step, the increased filling amount is 2 mm wider than the cut.

[0013] Specific operation steps for installing the compensation block:

[0014] First, loosen the compression positioning nut of the reinforced nitrile rubber strip and the upper rubber strip pressing plate of the reinforced nitrile rubber strip, pull out the bolt, cut the reinforced nitrile rubber strip, pull out the alder, insert and fix the supplemented and lengthened rubber block, place the alder, install and fix the bottom rubber strip pressing plate at the bottom of the supplemented and lengthened rubber block, connect the positioning bolt, place the upper rubber strip pressing plate and the compression positioning nut, and then connect them to form an integral body with the overall reinforced nitrile rubber strip.

[0015] By analyzing the assembly structure and sealing principle of the rubber blocks in the gas holder, the rubber blocks are divided into four parts inside the gas holder, and each part is elastically fixed by a row of pressing devices. After long-term wear, the circumferential tension of the rubber blocks between the pressing devices affects the further fitting of the rubber blocks to the sides. In view of the actual wear amount of the rubber blocks, the present invention adds rubber blocks with appropriate lengths to local positions, which neither increases the tension in other parts nor eliminates the circumferential tension of the rubber blocks, achieving the purpose of extending the service life of the rubber blocks.

[0016] The beneficial effects of the present invention are as follows:

[0017] According to the interaction principle of lengthening the sealing rubber strip and adding force by the lever counterweight, after the worn sealing rubber strip is supplemented and lengthened and the force is applied by the lever counterweight, it fits tightly with the side plate of the cylindrical cabinet body, reducing the leakage amount of the sealing oil, eliminating the major safety accident of gas pressure breaking through the piston sealing oil groove of the gas holder caused by the reduction of the oil level, and reducing the number of times of replacing all the sealing reinforcing nitrile rubber strips.

[0018] By installing and supplementing and lengthening rubber blocks on one side of the corner of the column of the POC gas holder, the sealing rubber strip can be lengthened. As the number of supplementing points increases, the sealing rubber strip within one circle of the gas holder piston is lengthened as a whole, and then through the lever counterweight force application mechanism, it is forced to fit tightly with the cylindrical cabinet body, reducing the leakage amount of the sealing oil; thus achieving the purpose of supplementing and lengthening the sealing rubber strip.

[0019] Conventionally, increasing the radial compensation causes skew to 730 sets of pressing devices, with a low sealing effect and uneven stress, which instead increases the wear amount of the rubber blocks. The solution of the present invention to the sealing rubber blocks according to the total compensation amount, the offset amount of the pressing devices and the misalignment compensation not only solves the problems of increased maintenance cost for replacing the sealing rubber blocks and reduced effective operation time, but also solves the adverse effects brought by the conventional radial increase in compensation.

[0020] This installation technology is simple, convenient to replace, requires little investment and yields great results. Applying this set of equipment to the piston sealing rubber of the new POC dry gas holder solves the problem of potential equipment safety hazards caused by the wear of the sealing rubber, ensuring the safe and stable operation of the new POC dry gas holder.

[0021] Compared with the prior art, the beneficial effects of the present invention are: extending the service life of the sealing rubber blocks by about 2 years, reducing the procurement cost of the sealing rubber, and shortening the maintenance period by more than 50%. Brief Description of the Drawings

[0022] Figure 1 It is a schematic diagram of Embodiment 1 of the present invention.

[0023] 1 - Reinforcing nitrile rubber strip; 3 - Supplementing and lengthening rubber block; 4 - Bottom rubber strip pressing plate; 5 - Upper rubber strip pressing plate; 6 - Bolt; 7 - Nut; 8 - Alder. Detailed implementation manners

[0024] The present invention will be further described below in conjunction with the accompanying drawings of the specification:

[0025] Example 1: 300,000 m³ blast furnace gas holder (No. 2)

[0026] The starting times of the 6 groups of oil pumps of this gas holder exceeded 40 times (according to the design requirements). After the piston landed, all the sealing oil was drained. The wear amount of the rubber blocks was measured, and the remaining service life was calculated based on the operation cycle. The remaining amount was 68%, and it was decided to take compensation measures for the rubber blocks.

[0027] First step: Cut each section of the sealing blocks between the columns, observe the springback amount of the cutting edge. When the springback amount exceeds about 15 mm, synchronously cut the other four blocks, and naturally fill the compensation blocks; Second step: Cut the rubber blocks on both sides of the cutting point in the first step respectively, measure the springback amount of the cutting edge to be about 8 mm, increase the filling amount by 10 mm wider than the cutting edge, and appropriately compensate the cutting edge in the first step to achieve overall free compensation by filling; Third step: Adjust the flatness of each compensation block and press it tightly with angle steel to prevent it from falling off or shrinking towards the piston side; Fourth step: Adjust the counterweight of the pressing device; Fifth step: Adjust the remaining three sections according to the first four steps, and there is springback in all of them, and increase according to the amount; Sixth step: Inject oil and supply gas, raise the piston, observe the starting frequency of the oil pump, and adjust the pressing device until the best state.

[0028] Specific operation steps for installing the compensation blocks:

[0029] First, loosen the compression positioning nut 7 of the reinforced nitrile rubber strip and the upper rubber strip pressing plate 5 of the reinforced nitrile rubber strip 1, pull out the bolt 6, cut the reinforced nitrile rubber strip, pull out the alder 8, insert the supplemented and lengthened rubber block 3 and fix it well, place the alder 8, install and fix the bottom rubber strip pressing plate 4 at the bottom of the supplemented and lengthened rubber block, connect the positioning bolt 6, place the upper rubber strip pressing plate 5 and the compression positioning nut, and then connect them to the overall reinforced nitrile rubber strip to form an integral body.

[0030] Example 2: 300,000 m³ blast furnace gas holder (No. 1)

[0031] The starting times of the 6 groups of oil pumps of this gas holder exceeded 40 times (according to the design requirements), reaching 46 times. It was originally planned to replace the rubber blocks. After the piston landed, all the sealing oil was drained. It was found that the wear amount of the rubber blocks did not exceed 50%, and the gas holder had been in operation for 3 years. It was decided to try to take compensation measures for the rubber blocks.

[0032] Step 1: Cut each sealing block between the columns and observe the springback amount of the cutting edge. When the springback amount exceeds about 12 mm, synchronously cut the other four pieces, and naturally fill the compensation block. Step 2: Cut the rubber blocks on both sides of the cutting point in the first step respectively, measure the springback amount of the cutting edge to be about 6 mm, increase the filling amount to be 8 mm wider than the cutting edge, appropriately compensate the cutting edge in the first step, and fill to achieve overall free compensation. Step 3: Adjust the flatness of each compensation block and press it tightly with the angle steel to prevent it from falling off or shrinking towards the piston side. Step 4: Adjust the counterweight of the pressing device. Step 5: Adjust the remaining three sections according to the first four steps. There is springback in all of them, and the amount is increased according to the measurement. Step 6: Inject oil and supply gas, raise the piston, observe the starting frequency of the oil pump, and adjust the pressing device until it reaches the best state.

[0033] Specific operation steps for adding the compensation block:

[0034] First, loosen the pressing and positioning nut 7 of the reinforced nitrile rubber strip and the upper rubber strip pressing plate 5 of the reinforced nitrile rubber strip 1, pull out the bolt 6, cut the reinforced nitrile rubber strip, pull out the alder 8, insert and fix the additional lengthened rubber block 3, place the alder 8, install and fix the bottom rubber strip pressing plate 4 at the bottom of the additional lengthened rubber block, connect the positioning bolt 6, place the upper rubber strip pressing plate 5 and the pressing and positioning nut, and then connect them to form an integral body with the overall reinforced nitrile rubber strip.

Claims

1. A method for repairing the seal of a POC dry gas holder, characterized in that, When the gas holder stops running, all the sealing oil is drained after the piston lands. Calculate the compensation demand, then adjust the sealing overlap point, symmetrically adjust the compensation amount at the sealing connection point, reduce the circumferential tension, improve the fitting amount of the rubber block and the side plate, and indirectly achieve radial compensation. After the sealing oil of the gas holder is drained, measure the wear amount of the rubber block, calculate the remaining service life according to the operation period. When the remaining amount exceeds 50%, take compensation measures for the rubber block. Step 1: Cut each section of the sealing block between the columns and observe the springback amount of the cut. When the springback amount exceeds 1 cm, synchronously cut the other four pieces and naturally fill the compensation block. Step 2: Cut the rubber blocks on both sides of the cutting point in the first step respectively, measure the springback amount of the cut, and make the filling amount 1-5 mm wider than the cut to appropriately compensate the cutting point in the first step and achieve overall free compensation by filling. Step 3: Adjust each compensation block to be flat and press it tightly with angle steel to prevent it from falling off or shrinking towards the piston side. Step 4: Adjust the counterweight of the pressing device. Step 5: Adjust the remaining three sections according to the first four steps, and adjust the amount according to the actual additional compensation. Step 6: Inject oil and supply gas, raise the piston, observe the starting frequency of the oil pump, and adjust the pressing device until it reaches the best state. Specific operation steps for installing the compensation block: First, loosen the compression positioning nut of the reinforced nitrile rubber strip and the upper rubber strip pressing plate of the reinforced nitrile rubber strip, pull out the bolt, cut the reinforced nitrile rubber strip, pull out the alder, insert the supplemented and lengthened rubber block and fix it, place the alder, install and fix the bottom rubber strip pressing plate at the bottom of the supplemented and lengthened rubber block, connect the positioning bolt, place the upper rubber strip pressing plate and the compression positioning nut, and then connect them with the overall reinforced nitrile rubber strip to form an integral body.

2. The method for repairing the seal of a POC dry gas holder according to claim 1, characterized in that, In the second step, the filling amount is 1-3 mm wider than the cut.

3. The method for repairing the seal of a POC dry gas holder according to claim 2, characterized in that, In the second step, the filling amount is 2 mm wider than the cut.

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