JPH02302495A - Overhead corrosion simulator - Google Patents

Abstract

PURPOSE: To provide the subject simulator provided with many cells each containing a plurality of temperature measurement probes and a plurality of corrosion measurement probes and being capable of measuring the corrosion rates on the metal surface of a heat exchanger at various temperatures.

CONSTITUTION: An inclined U-tube is provided inside a water box 10, the tube 12 is connected in series to a plurality of cells 14a-14h each having a baffle wall, each cell is provided with means for monitoring corrosion, namely probes 26 and 28 each having a thermocouple for measuring temperature. The cells 1a to 1h for collecting a liquid and a gas are separated from each other by their baffle walls to form a set of cells spaced from each other by the baffle walls, and the liquid is collected by the cell set. Since the gas phase exists just over the collected liquid phase, corrosion can be measured in both phases in the cell and the liquid phase.

COPYRIGHT: (C)1990,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to the liquid and gas phases of petroleum distillation equipment in order to be able to introduce corrosion inhibitors for the control of corrosion in petroleum distillation equipment. The present invention relates to an improved apparatus for investigating corrosion in both phases of petroleum distillation equipment, and more particularly to an overhead corrosion simulator for simulating the corrosion profile of petroleum distillation equipment.

[Conventional technology]

Crude oil is distilled in refineries to produce various petroleum components such as gasoline, fuel oil, and lubricating oil.

This is accomplished by fractionation and refining equipment, which exposes the refining equipment to corrosion as corrosive components are contained in the crude oil and carried along the refining zone. Corrosion occurs on the surfaces of equipment, especially on the internal surfaces of condensing and heat exchange units. The most severe points of water-induced corrosion activity are near the points where water first condenses.

In the past, there have been many systems and devices for corrosion detection, but they have considerable shortcomings in obtaining a suitable corrosion profile. For example, equipment may be inspected for corrosion using ultrasonic test units that measure metal thickness by reflected sound waves. This corrosion investigation method is limited to cases where many failures in purifiers occur on the surfaces of heat exchange equipment, such as condensers or continuous fan tubes, because the tube surfaces are inaccessible without closing the purifier. It is not possible to measure metal losses in such areas.

Weight loss coupons are used to detect metal loss rates and are placed in the process stream. Data obtained with such weight loss coupon systems only indicates corrosion at the point in the system where the weight loss coupon is placed. It has been found that in order to use corrosion rates to predict equipment conditions, the most corrosive points in the system must be monitored, typically at the point where water first condenses at the water's dew point. It's about to start. This location is found on tube surfaces within heat exchange equipment and continuous fans, where weight loss coupons cannot be easily placed, so the weight loss coupon system cannot be used at such points. cannot be adopted. Furthermore, the point at which water first condenses changes over time, so fixed placement of weight loss coupons is only of value for a limited time. Finally, weight loss coupon systems cannot quickly recognize brief upsets.

Electrical resistance type probes have also been used, but these also always read the corrosion rate only at a point in the system and are subject to the same limitations as weight loss coupon systems.

However, electrical resistance type probes are superior to weight loss coupon systems because they generate data more quickly and overcome the problem of quickly recognizing short failures.

Although flow sampling is effective in monitoring corrosion activity and recognizing malfunctions, they cannot differentiate between extremely severe localized pitting (holes) or slow corrosion of the system.

Furthermore, as described in US Pat. No. 3,649,167, a device for measuring corrosion potential is known which analyzes the situation of initial condensation when the ambient temperature reaches the dew point of the water. However, this device does not indicate metal loss or corrosion activity.

A device that solved many of these problems was U.S. Patent No. 433.
No. 5072, which is also referred to herein. In the Barnett et al. patent, an overhead corrosion simulator is described that allows monitoring of a liquid environment in contact with metal surfaces on the process side of an oil refinery. The details of the overhead corrosion simulator of the Barnett et al. patent are as follows.

The Barnett et al. patent eliminates the above-mentioned conventional methods by allowing the corrosion rate present at any point in an overhead system to be quickly and accurately measured, thereby allowing process control programs to be monitored and optimized. This solves the problem of measuring corrosion in oil refinery equipment. The Barnett et al. patent is an overhead corrosion simulator, which is a compact overhead system that simulates the corrosive environment present on the condenser surface of a monitored bus process unit. This overhead corrosion simulator receives a slipstream of a hydrocarbon process gas stream at a temperature significantly above the water dew point, cools this slipstream, and cools the slipstream over a range of temperature differences above and below the dew point. to measure the corrosion rate. Corrosion rates at various temperatures are examined to obtain a corrosion profile for the equipment, and corrosion inhibitors are then injected at appropriate locations to reduce corrosion for the particular branch steam encountered. Electrical resistance type probes can be used to measure corrosion activity.

In addition to corrosion measurements, Barnett et al.'s overhead corrosion simulator can be used to measure the release of hydrogen elements from corrosion reactions where hydrogen blister action is likely to occur. The Barnett et al. patent also allows for the use of a weight loss specimen system to measure corrosion, particularly where extensive corrosion is present. In water-dominant phase systems, polar probes such as those used in water cooling programs may also be used to measure corrosion potential. It should also be understood that Barnett et al.'s overhead corrosion simulator can be mounted in combination with any corrosion measurement equipment as desired. Temperature measurement probes can be used to measure temperature at various points in the overhead corrosion simulator to correlate temperature and corrosion rate. Additionally, sampling lines may be provided at various points along the coil for the extraction of condensate samples to perform other appropriate tests to aid in analyzing the corrosion protection program.

Accordingly, the Barnett et al. patent provides a novel and improved device that can quickly and accurately measure the corrosion rate present at any point in oil refinery equipment in order to quickly and effectively improve the onset of corrosion control. It was something to offer.

The Barnett et al. patent provides a corrosion simulator that simulates the corrosive environment that exists on the surface of a condenser or heat exchange device used in oil refining equipment; A water box with a coil is provided for measuring corrosion occurring on metal surfaces, through which a stream of hydrocarbon vapor is passed and cooled, and a plurality of corrosion detection means and temperature detection means are arranged on the coil. It was designed to measure corrosion that occurs at various temperatures by attaching it at points along the line, allowing a temperature-corrosion profile to be obtained.

[Problem to be solved by the invention]

The present invention overcomes the problems encountered when using devices such as those of Barnett et al. In the Barnett et al. device, the probe used was brought into contact only with the liquid phase obtained by condensing vapor from an oil refinery. Although Barnett et al.'s device was a significant improvement over previously existing devices, it was limited to measuring corrosion in the liquid phase and did not allow for the possibility of corrosion in both the liquid and gas phases. could not be measured.

The present invention significantly improves the measurement concept of Barnett et al. without modifying the measurement concept. The present invention receives a gaseous process gas stream sample, condenses the process gas stream sample in a designated heat exchange device, and
This specified heat exchange device has baffles arranged periodically along its length, these baffles forming cells that collect the condensed liquid, above which there is a gas space, A plurality of corrosion measuring probes are arranged in this cell along with a temperature measuring probe, and these probes are brought into contact with the liquid phase and the gas phase.

each cell having a plurality of temperature measurement probes and a plurality of corrosion measurement probes arranged therein is repeated to form a gradual temperature gradient along the length of the improved overhead corrosion simulator comprising a number of arrangement cells; This temperature gradient allows accurate determination of dew point and precise measurement of corrosion potential in both the liquid and gas phases along the length of the overhead corrosion simulator.

Improved overhead corrosion simulators, such as the device of Barnett et al., supra, can use electrical resistance-type probes to measure corrosion rates, or insert weight-loss coupons at the probe location. , the actual corrosion state of this weight loss specimen can be measured. When using these weight loss coupons, such measurements require more time than instantaneous readings from electrical resistance type probes.

It is therefore an object of the present invention to quickly and accurately measure the corrosion rate present at every point in a petroleum refinery when the metal is in contact with both the liquid and gaseous phases, thereby quickly and effectively determining the corrosion situation. An object of the present invention is to provide an improved overhead corrosion simulator that can be used to improve corrosion control programs controlled by the addition of corrosion inhibitors.

Another object of the invention is to reflect the corrosive environment present in condensing or heat exchange equipment installed in oil refineries, whether the corrosive environment is due to liquid-to-metal contact or gas-to-metal contact. An object of the present invention is to provide an improved overhead corrosion simulator.

Still another object of the present invention is to provide an improved overhead corrosion simulator that can be installed in an oil refinery to measure corrosion occurring on the metal inner surfaces of heat exchange equipment, the simulator having a water box and a an angled U-tube, the U-tube including a baffle wall forming a plurality of cells arranged in series, and means for monitoring corrosion, i.e., means for inserting a probe, the probe further comprising: includes a thermocouple to measure temperature, and a baffle wall separates a cell that collects liquid and gas, the cells are arranged in series in a U-tube having an inlet and an outlet, and a buckle wall separates the cells in spaced pairs. and allow the liquid to collect within the cells, so that there is a gas phase directly above the collected liquid phase, thus providing an opportunity to measure corrosion in both the gas and liquid phases within each cell. provide.

Yet another object of the invention is to produce a controlled temperature drop in the range of 40°C to 70°C, which temperature drop in each cell is in the range of 6°C to 8°C, with the result that condensation occurs by checking the dew point. It is an object of the present invention to provide an improved overhead corrosion simulator that can obtain precision in investigating the corrosion potential present in both gas and liquid phases.

〔Example〕

Referring to FIGS. 1 to 3, the overhead corrosion simulator according to the present invention includes a substantially rectangular water box 10, which is placed on a pedestal 11, for example. A U-shaped tube 12 is arranged inside the water box 10. 8 in series with U-shaped tube 12
Cells 14a to 14h are formed in series. In particular, as is clear from FIG. 2, a steam inlet 16 and a steam outlet 18 are provided on the side of the water box 10, and an overhead steam line leading from a fractionation column of an oil refinery (not shown) to condensate or a heat exchange device is provided. Process gas (steam) may be introduced into the steam inlet 16, passed through the eight cells 14a to 14h of the U-tube 12, and exhausted through the steam outlet 18 and returned to the appropriate location in the oil refinery. This return position is chosen such that the pressure there is lower than the pressure at the inlet, so that such pressure relationship allows steam to flow into the U-tube 12.

Referring to FIGS. 1 and 6, a partition wall 20 extends along the center of the U-shaped tube 12 in the water box 10, forming a cooling water passage along the U-shaped tube 12 in the water box 10. . Referring to FIG. 2, a cooling water inlet 22 and a cooling water outlet 24 are provided on the side of the water box 10 where the steam inlet 16 and the steam outlet 18 are located. However, the steam inlet 16 is, for example, on the right side with respect to the partition wall 20, and the cooling water inlet 22 is, for example, on the left side with respect to the partition wall 20. Therefore, the flow direction of the cooling water is opposite to the flow direction of the steam, and by controlling the temperature of the cooling water and the flow rate of the cooling water, the steam flowing through the U-shaped pipe 12 is directed to each cell 14a to 14a.
The temperature can be lowered continuously every 4 hours.

For example, the temperature decreases from 6°C to 8°C for each cell 14a to 14h.
in the range of ℃.

As shown in FIGS. 1, 3 and 4, the U-shaped tube 1
2 is inclined with respect to the horizontal, and the cell 14a near the steam inlet 16 is at the highest position, and the adjacent cells are at the lowest position in order, and the cell 14h near the steam outlet 18 is at the highest position.
is the lowest position.

The water box 10 has a vertical dimension of 3 inches (94 cm), a horizontal dimension of 1 inch (43 cm), and a height of 8.25 inches (21 cm). Steam inlet 16 and steam outlet 18
The lateral distance between them is 7.5 inches (15 cm), and the height difference between steam inlet 16 and steam outlet 18 is 2.5 inches (6 cm). However, this dimension is for illustrative purposes only and is not intended to limit the invention.

FIG. 5 shows cells 14a of the U-tube 12 near the steam inlet 16, each cell being defined by a baffle wall 12a provided within the U-tube 12. baffle wall 1
2a includes at least a vertical wall portion extending upward from the bottom inside the U-shaped tube 12, so that the liquid condensed from the vapor flowing in from the direction of the arrow collects after the puffful wall 12H, and the gas phase and liquid are separated in each cell. A phase is formed.

-11 each! Two probes 26 and 28 are arranged in the channels 14a to 14h. One probe 26 is inserted so as to contact the liquid phase within the cell, and the other probe 28 is inserted so as to contact the gas phase above the liquid phase. Furthermore, a drain or sampling tube 30 is connected to each cell 141 to 14h near the end of the cell where condensed liquid always exists (i.e., near the baffle wall 12a). 2, each tube 30 is connected to a collection section 32. In this way, the liquid sample can be collected. , this liquid sample can be discarded or used for analysis.

As described above, each cell 14 is connected to the steam flowing through the U-shaped tube 12.
The temperature can be continuously lowered every 14 hours. The temperature gradually decreases from cell 14a to cell 14h. In the embodiment, eight cells 141~
Although 14 h are provided, in the present invention, other numbers of cells, for example 4 to 20 cells, preferably 6 to 10 cells, may be provided as necessary. This provides the possibility to determine the exact dew point and to determine changes in the composition of the condensed liquid and the vapor in contact with the condensed liquid. The temperature can be carefully varied by controlling the cooling water supply temperature and the cooling water supply. Such control can be performed manually or automatically by providing an automatic temperature control device. Each cell therefore operates at a different equilibrium, providing the best opportunity to measure dew point and corrosion potential.

FIG. 4 shows an enlarged view of the inclined U-tube 12 of the overhead corrosion simulator according to the present invention, and further shows that a drain or sample tube 30 is provided for each cell 14a to 14h. There is. Each of the cells 141-14h is formed between a pair of baffle walls similar to the baffle walls 12a of FIG. 5 arranged in series along substantially the entire length of the U-shaped tube 12, and are formed similarly to each other. This U-tube 12 is arranged in a closed stainless steel structure, and the closed stainless steel structure is designed to provide a counterflow of cooling water in order to obtain the above temperature gradient.

The temperature gradient that can be achieved with the present invention is such that the cell 14h near the steam outlet 18 is approximately 40°C to 70°C lower than the temperature of the process gas to which it is supplied or the temperature of the cell 14a near the steam inlet 16. Preferably, it is adapted to operate at .

As the probes 26 and 28, known probes can be used, such as those described in the aforementioned US Pat. No. 4,335,072. The probe is of the electrical resistance type, measuring corrosion by resistance to electrical current, and may also include a separate thermocouple to simultaneously measure temperature.

As described in the aforementioned US Pat. No. 4,335,072, the most severe points of water corrosion are near the points where water first condenses. This point constantly moves due to changes in the partial pressure of the gas, changes in the composition of the gas, variations in total pressure, as well as variations in temperature, etc. The overhead corrosion simulator of the present invention has a plurality of temperature regions formed by cells 141 to 14h provided in series by the baffle wall 12a in the inclined U-shaped tube 12, thereby changing the position of the most severe point of corrosion. It is to monitor. Having these multiple cells 14a-14h allows corrosion rates to be measured at all points in the system, with different temperature ranges, so that the results are consistent with actual operation within the refinery equipment. By comparison, the corrosion potential at any location in the overhead system of an operating refinery facility can be quickly and accurately determined.

As previously mentioned, different corrosion measurement probes can be used in each temperature range. For example, an electrical resistance type probe can be used to measure corrosion rate in mls/year. Such probes work on the principle that electrical resistance changes as the probe corrodes, providing an insight into corrosion rates.

As the cross-sectional area decreases, the electrical resistance increases and this increased electrical resistance can be read from a suitable recording device connected to the corrosion simulator of the invention. One such probe is manufactured by Rohrbach Instruments and carries the trademark CORRO3OMET.
It is commercially available as BR. In some installations, particularly those where extensive corrosion is present, the corrosion measurement probe may be of the retractable coupon type. The coupon can be in sheet-like form or can be mounted as a cylinder. Where hydrogen blistering is a problem, the probe can be a hydrogen probe that measures the release of elemental hydrogen from the corrosion reaction. Furthermore, it should be understood that any combination of probes can be used in the overhead corrosion simulator of the present invention.

In addition to the corrosion probes, a temperature probe auxiliary to each corrosion probe allows temperature versus corrosion rate relationships to obtain a temperature corrosion profile. This is achieved in that the corrosion probe inserted into each cell of the device of the invention is equipped with a thermocouple, twenty thermocouples measuring the temperature and allowing this temperature to be read out at the request of the operator.

In operation, slipstreams of hydrocarbon process gas streams are withdrawn from the center of the steam line where these vapors reside.

These vapors are best collected by inserting a vapor sample tile into the vapor line, which is connected to an overhead corrosion simulator. The vapor sample tile can be inserted through the pipeline assembly through a process line valve or packing gland located in the process line.

The vapor sample tile is mounted so that the vapor sample is collected at or near the center of the process line. This improves the operation of the overhead corrosion simulator by ensuring that the sample taken is initially in a vapor state. The length of the vapor sample tile is specified 1 and installed such that the above position is achieved. Preferably, the vapor sample tile is made of a non-corrosive alloy material, such alloys as e.g. Monel
400 alloy. The support rods and plates and nuts and screws that support the vapor sample tiles should be made of Monel 400, or other non-corrosive alloy material such as 304 stainless steel, or the same non-corrosive alloy material. Preferably, if a packing gland is used, the packing material is Teflon (
registered trademark) or other environmentally resistant plastic materials. All other parts of the probe are made of ordinary carbon steel.

Probes typically range from ambient pressure to 350 psi (
pressure range (including) and ambient temperature up to 550〒 (
The steam sample tile of such an overhead corrosion simulator is shown in FIG. 7.

In FIG. 7, the vapor sample tile is supported by support ronds and plates, and the necessary equipment for mounting via process line valves or packing glands is shown.

A plurality of such vapor sample tiles are then placed in direct connection with the overhead corrosion simulator of the present invention. Care must be taken to minimize the spacing between the non-sampling end of the steam sample tile and the inlet end of the overhead corrosion simulator of the present invention. In addition, the tube or pipe spacing between the vapor sample tile and the overhead corrosion simulator inlet should be insulated or heated so that there is no condensation or at least minimal condensation between the sampling point and the overhead corrosion simulator inlet. Should be traced.

In operation, a branch vapor of a process gas stream is obtained from an overhead steam line of an oil refinery, preferably by using the vapor sample tile described above, and is passed through a U-tube 12 provided with cells with sloped baffle walls. be done. Valves are provided to control the flow of steam to the overhead corrosion simulator and to control the flow of opposing cooling water. The cooling water is supplied from the cooling water outlet 2 of the water box 12.
The steam is also discharged from the steam outlet 18.

Each cell is provided with a corrosion and temperature probe 26, 28 as described above. These probes 26, 28 make it possible to measure the corrosion potentiometer temperature, and other devices measure the flow rate according to the devices installed in each cell and the monitoring device of the overhead corrosion simulator. The water pressure is regulated by any regulator that can be attached to the cooling water supply and maintained at the desired level at all times, ensuring uniform cooling along the U-tube 12 and a stable temperature in each cell of the U-tube 12. The angled U-tube 12 is maintained fully submerged to provide control. As the cooling water passes through the water box 10, its temperature increases so that each cell operates at a slightly higher temperature than the previous cell due to the counterflow of cooling water.

In other words, the cells on the inlet side that directly receive the process gas operate at a higher temperature, and the subsequent cells operate at a lower temperature. These cells preferably operate at a temperature between 6 and 8 degrees Celsius lower than the previous cell, as described above.

Compared to the above US patent, the present invention has corrosion and temperature probes arranged in the angled U-tube 12 so that each probe of each cell detects either the liquid condensed within the cell or the vapor in direct contact with the liquid. can be placed in contact with the Accordingly, the present invention can measure the corrosion potential of both the liquid and gas phases as well as the temperature of the liquid and gas.

This improvement provides better control of the equipment, better measurement of accurate dew point, and improved corrosion potential for both liquid and gas phases.

This device can be installed in the overhead line of an operating oil refinery and can quickly and accurately measure the corrosion potential of both liquid and gas phases. From these readings, operators can activate corrosion potentials and add corrosion control chemicals as needed to protect equipment.

The following table shows an example of test results obtained with the device of the invention. Table 1 shows the measurement results using the probe brought into contact with the gas phase, and Table 2 shows the measurement results using the probe brought into contact with the liquid phase.

111KI to WK5 are corrosion rates (1
/1000 inches/year).

PROBE# TEMP(F) 1tlK I
WK 21 255 0.2
0.03 253 2.8 2.1
5 253 0.0 0.0?
245 0.0 0.09 23
8 0.0 0.611 232
0.0 0.813 229 0
．． 00.515 224 0.0 0
．． 3 table PROBE# TEMP(F) WKI
WK22 253 15.4 0.0
4 250 g, 9 Q, 46
248 0.0 0.08 2
42 8.4 0.010 235
9.2 0.012 230 1
2.2 0.714 220 7.5
1.8WK3 4 on the palanquin 5 on III
o, o o, o o,.

O, 03, 4 [IFF o, o　　　o, o　　o,.

O,0OFF 0FF O,80,00,0 1,20,00,0 0,90,00,0 1,50,60,1 WK3 WK4 WK5 0.0 OFF 0FF O,60,6G,5 0.0 0.0 0.0 0.0 0.0 0.0 0.9 0.0 0.0 0.3 0.4 0.1 1.3 0.4 0.9 As is clear from the above explanation , according to the invention, to quickly and accurately measure the corrosion activity of the internal surfaces of condensing or heat exchange equipment in both the liquid and gas phases by means of a corrosion simulator installed and operated in a petroleum refinery or petroleum plant. I can do it. This measurement can be monitored by a monitoring device and used to optimize corrosion inhibitor dosing.

[Brief explanation of drawings]

FIG. 1 is a plan sectional view of an overhead corrosion simulator according to the present invention, FIG. 2 is a side view of FIG. 1, and FIG.
Figure 4 is an enlarged detailed view of Figure 3, Figure 5 is a front view of Figure 4, and Figure 5 is a U
FIG. 6 is a cross-sectional view showing one cell of the U-shaped tube, FIG. 6 is a plan view of the U-shaped tube, and FIG. 7 is a diagram showing a steam sample tile. 10...Water box, 12...U-shaped tube, 14
a-14h...Cell, 26/28...Probe. Figure 1 Figure n Figure 2 Figure 6 Figure 7 Procedural amendment (method) % formula % 1. Display of the case 1999 Patent Application No. 107931 2 Name of the invention Overhead corrosion simulator 1 Person making the amendment Related Patent applicant name: Nalco Chemical Company 4, agent address: 8-10-6, Toranomon-chome, Minato-ku, Tokyo 105
Subject of amendment (1) "Representative of applicant" column of application (2) Power of attorney (3) Clearance 1 7. Contents of amendment (1) (2) As shown in the attached sheet (3) B8 + 10 removed (Inner room - (-19 none) 8, List of attached documents (1) Application for correction, letter (2) Power of attorney and translation (1 copy each) (3) Sei 8g!1lTh4 1 Written amendment to legal procedures (voluntary) 1999 September 13, 2016 Director General of the Japan Patent Office Yoshi 1) Moon Takeshi 1, Indication of the case 1999 Patent Application No. 107931λ Name of the invention Overhead corrosion simulator 3, person making the amendment Relationship to the case Patent applicant 4, Agent Person Address: Shizuka Toranomon Building, 8-10 Toranomon-chome, Minato-ku, Tokyo 105 Telephone number: 504-07215 Subject of amendment (1) “Claims” column in the specification (2) “Claims of the invention” in the specification "Detailed Description" column 6, Contents of amendment (1) The claims are amended as shown in the attached sheet. (2) Page 17 of the specification, lines 111 to 122 “4
0°C to 70°C” is corrected to “about 4°C to about 26°C”. (3) Page 17, line 133 of the specification: “6°C to 8°
Correct CJ from r3°C to 4.5°CJ. (4) Page 19, line 111 of the specification: “6°C to 8°
C' is corrected from r3°C to 4.5°CJ. (5) Page 22, line 200 of the specification [from 40°C to 7
0°C" is corrected to "4°C to 26°C." (6) "550 yen" on page 27, line 4 of the specification is r2
Correct to 88°C. (7) Page 27 of the specification, line 5 r 1000″F”
is corrected to r538°C. (8) Page 29, line 111 of the specification [6°C to 8°
Adjust Cl from 13 °C to 4.5 °CJ. 7. List of Attached Documents Claims 1 copy 2. Claims 16 A petroleum refinery having a fractionating column, the fractionating column being connected to a condensing and/or heat exchange device by an overhead steam line. an overhead corrosion simulator for simulating and measuring corrosion activity on an internal surface of said condensing and/or heat exchange device, wherein said corrosion activity occurs when internal metal surfaces are in contact with condensing liquid and in contact with vapor; The overhead corrosion simulator includes a water box and an inclined U-tubular corrosion simulator disposed within the water box, and the U-tubular corrosion simulator is connected to the overhead steam line. said U-tubular tube having an inlet connected to said U-shaped tube for receiving a branch vapor of a hydrocarbon process gas stream at a temperature substantially the same as the operating temperature and substantially above the dew point of water in the stream; the corrosion simulating device includes panful walls forming a plurality of cells arranged in series;
The cells include means for connecting corrosion probes and temperature probes, the probes being adjusted to contact the vapor and liquid phases within each cell, and the cells providing measurements of branch vapors of the condensing process gas stream. incrementally repeating along a temperature range below the entry temperature of the branch vapor of the process gas stream, and the U-tubular corrosion simulator is connected to an outlet, the outlet being connected to an outlet of the U-tubular. The water box is connected to a point in the oil refinery such that a sufficient pressure drop is achieved through the overhead corrosion simulator to ensure steam movement through the corrosion simulator, and the water box further directs cooling water. a U-shaped tubular corrosion simulation having an inlet and an outlet to allow the cooling water to flow, the cooling water flow lowers the temperature relative to the incoming stream of the branch steam of the process gas stream, and the corrosion probe and the temperature probe are inclined. An overhead corrosion simulator that can measure the corrosion rate at various temperatures in both the gas phase and the liquid phase in each cell that forms the overhead corrosion device. Claim 1 wherein the z8 corrosion probe includes a temperature probe for measuring temperature and corrosion rate and obtaining a temperature-corrosion profile for the condensation and/or heat exchange device.
Overhead Corrosion Simulator as described in . 3. The overhead corrosion simulator of claim 1, further comprising a sample line in each cell to sample the condensed liquid phase collected after the baffle wall of each cell. 4. further comprising means for regulating the flow of a branch steam of the process gas stream and means for regulating the supply of cooling water to control the temperature drop through the inclined U-tubular corrosion simulator; 3. The overhead corrosion simulator of claim 2, wherein the corrosion monitoring device regulates the process gas passing through the inclined U-tubular corrosion simulator within a predetermined temperature reduction range. 5. The inclined U-tubular corrosion simulator can collect liquid after the baffle wall of each cell so that the corrosion probe and temperature probe are sufficiently immersed; 2. The overhead corrosion simulator of claim 1, wherein the overhead corrosion simulator is inclined from the inlet to the outlet at an angle such as to provide sufficient steam space for insertion of the simulator. 6. The overhead corrosion simulator of claim 1, further comprising a sample line for sampling chloride, vapor (pH), salt, or a mixture thereof in each cell of the inclined U-tubular corrosion simulator. 7. A device for simulating and measuring corrosion activity on the inner surface of a condensing and/or heat exchange device installed in a petroleum refinery, the device having a steam line above the fractionation column; The steam line includes an alloy sampling quill, the sampling quill is positioned in the steam line to obtain a sample of steam at the center of the steam line, and the sampling quill is configured to conduct an overhead corrosion simulation. the overhead corrosion simulating device includes a water box and an inclined U-shaped tube provided in the water box;
Corrosion probe and temperature probe connection means comprising baffle walls arranged in series, each set of baffle walls forming a cell, each cell connecting a corrosion probe and a temperature probe at two locations within each cell. the probes are adjusted such that when installed such a first probe of each cell is connected to the vapor space and such a second probe is connected to the liquid space; The tube has an inlet connected to a sampling quill, which is subsequently connected to an overhead steam line to process hydrocarbons at a temperature substantially above the dew point of water within the sampling gas stream. the U-tube further having an outlet connected to the U-tube and comprising means for regulating the flow of the branch vapor of the process gas stream; has a cooling water inlet and an outlet;
means for regulating the flow of branch steam of the process gas stream, the flow of cooling water opposing the flow of branch steam of the process gas stream, and means for supplying regulated cooling water to an inlet of the cooling water; adjust the temperature of the steam flowing through the U-tube, each cell containing two probes, and a plurality of cells connected in series to adjust the temperature of the steam flowing through the U-tube. Probes and corrosion probes are installed.
Apparatus wherein the probe measures temperature and corrosion rate and obtains a temperature-corrosion profile for metals in contact with both gas and liquid phases of a condensing and/or heat exchange device. 8. The apparatus of claim 7, wherein the angled U-tube slopes downwardly from the inlet to the outlet. 9. The method of claim 8, further comprising a sample line disposed in each cell to obtain a sample of the liquid, the liquid sample being monitored for chloride, pH, salinity, or a mixture thereof. Device. 10. The water box includes a plurality of baffle walls, the baffle walls being arranged in an alternating manner to provide adjacent connected compartments, the compartments forming a winding or sinusal sortal path for the cooling water; An angled U-tube has a plurality of connected legs in each cell so that liquid collected between the baffle walls forming the cell can be collected and analyzed, and each cell has both corrosion probes. and two means for inserting the temperature probe such that one is in contact with the liquid and the gas and the other is not.

Claims (1)

[Scope of Claims] 1. In an oil refinery having a fractionating column, and the fractionating column is connected to a condensing and/or heat exchange device by an overhead steam line, the condensing and/or heat exchange device is an overhead corrosion simulator for simulating and measuring corrosion activity on internal surfaces, such corrosion activity including activity where internal metal surfaces are in contact with condensed liquid and in contact with steam; comprises a water box and an inclined U-tubular corrosion simulator disposed within the water box, the U-tubular corrosion simulator being connected to the overhead steam line and at substantially the same operating temperature. the U-tubular corrosion simulator comprises a plurality of cells arranged in series, the U-tubular corrosion simulator having an inlet for receiving a branch vapor of a hydrocarbon process gas stream at a temperature substantially above the dew point of water in the stream; including a baffle wall forming a
The cells include means for connecting corrosion probes and temperature probes, the probes being adjusted to contact the vapor and liquid phases within each cell, and the cells providing measurements of branch vapors of the condensing process gas stream. incrementally repeating along a temperature range from 40°C to 70°C below the entry temperature of the branch vapor of the process gas stream, and the U-tubular corrosion simulator is connected to an outlet, the outlet being The water box is further connected to a point in the oil refinery such that a sufficient pressure drop is achieved through the overhead corrosion simulator so as to ensure the movement of steam through the U-tubular corrosion simulator. an inlet and an outlet for opposing flows of cooling water, the flow of cooling water providing a temperature reduction relative to the incoming stream of branch steam of the process gas stream, and a corrosion probe and a temperature probe that are inclined; An overhead corrosion simulator that can measure corrosion rates at various temperatures in both the gas phase and liquid phase in each cell forming a tubular corrosion simulator. 2. Each corrosion probe includes a temperature probe to measure temperature and corrosion rate and obtain a temperature-corrosion profile for the condensation and/or heat exchange device.
Overhead Corrosion Simulator as described in . 3. The overhead corrosion simulator of claim 1 further comprising a sample line in each cell to sample the condensed liquid phase collected after the baffle wall of each cell. 4. further comprising means for regulating the flow of a branch steam of the process gas stream and means for regulating the supply of cooling water to control the temperature drop through the inclined U-tubular corrosion simulator; The corrosion monitoring device measures the temperature drop from 50°C to 6°C through the inclined U-tubular corrosion simulator.
The overhead corrosion simulator according to claim 2, wherein the overhead corrosion simulator is adjusted in a temperature reduction range of 0°C. 5. The inclined U-shaped tubular corrosion simulator,
After the baffle wall of each cell, the angle is such that liquid can be collected so that the corrosion and temperature probes are sufficiently immersed, and that there is sufficient vapor space in which the corrosion and temperature probes are inserted. The overhead corrosion simulator of claim 1, wherein the overhead corrosion simulator is sloped from the inlet to the outlet. 6. The overhead corrosion simulator of claim 1, further comprising a sample line for sampling chloride, pH, salt, or a mixture thereof in each cell of the inclined U-tubular corrosion simulator. 7. A device for simulating and measuring corrosion activity on the inner surface of a condensing and/or heat exchange device installed in a petroleum refinery, the device having a steam line above the fractionation column; The steam line includes an alloy sampling quill, the sampling quill being positioned in the steam line to obtain a sample of steam near the center of the steam line passing through the steam line, and the sampling quill simulating overhead corrosion. connected to an inlet of the apparatus, the overhead corrosion simulating apparatus comprises a water box and an inclined U-tube disposed within the water box, the U-tube including a baffle wall disposed in series, and a The baffle walls form cells, each cell including corrosion probe and temperature probe connection means for connecting a corrosion probe and a temperature probe at two locations within each cell, the probes being connected to one another in each cell when installed. a first probe connected to the vapor space and a second such probe connected to the liquid space, the U-tube having an inlet connected to a sampling quill; A quill is subsequently connected to the overhead steam line to permit sampling of branch steam of the hydrocarbon process gas stream at a temperature substantially above the dew point of water in the sampling gas stream, and the U-tube further has an outlet connected to the U-tube and includes means for regulating the flow of a branch steam of the process gas stream, the water box having a cooling water inlet and an outlet, the water box having a cooling water inlet and an outlet; is opposed to the flow of the branch steam of the process gas stream and includes means for supplying regulated cooling water to the cooling water inlet, cooperating with the means for regulating the flow of the branch steam of the process gas stream. Adjusting the temperature of the steam flowing through the U-shaped pipe,
Each cell includes two probes, and a plurality of cells are connected in series to provide a plurality of temperature probes and corrosion probes in series cells along the U-tube, and the probes are configured to provide temperature and corrosion probes. Apparatus for measuring the rate and obtaining temperature-corrosion profiles for metals in contact with both the gas phase and the liquid phase of a condensing and/or heat exchange device. 8. The apparatus of claim 7, wherein the angled U-tube slopes downwardly from the inlet to the outlet. 9. further including a sample line placed in each cell to obtain a sample of liquid, the liquid sample being chloride, pH (PH);
9. A device according to claim 8, adapted to monitor , salinity or a mixture thereof. 10. The water box includes a plurality of baffle walls, the baffle walls being arranged in an alternating manner to provide adjacent connected compartments, the compartments forming a winding or sinusal sortal path for the cooling water; An angled U-tube has a plurality of connected legs in each cell so that liquid collected between the baffle walls forming the cell can be collected and analyzed, and each cell has both corrosion probes. and two means for inserting the temperature probe, one in contact with the liquid and the gas, the other not.