CN1103945A - Compound agent for carbon steel-water heat pipe hydrogen removing - Google Patents

Abstract

The invention is concerned with hydrogen-removing chemical with CuO as its main ingradient. While the chemical is combined with chemical passivation technique, it can effectively overcome inconsistency of steel and water in water heat transfer pipeline, so as to improve its work stability and double the service life of th pipeline.

Description

Compound agent for carbon steel-water heat pipe hydrogen removing

The present invention relates to a kind of technical field of handling with the metal material surface of chemical method.

Heat pipe with its efficiently heat transfer property attracted attention by the engineering industry, and carbon steel-water heat pipe is because its cost is low, makes simply, advantages such as adaptive temperature wide ranges are in the industrial application widely that obtains day by day.But owing to be used as the incompatibility of the carbon steel and the working media-water of tubing, make under the condition of in heat pipe anoxic, water and steel produce electrochemical reaction, generate tri-iron tetroxide and hydrogen, the hydrogen that generates is accumulated in the heat pipe, hinder flowing and heat release of working substance steam, cause the heat transfer property in the heat pipe to descend gradually, thus finally entirely ineffective.The carbon steel-water heat pipe of industrial use in the past for avoiding the incompatibility of tube wall and working solution, generally adopts copper material tube wall or copper iron multiple tube, makes that like this production cost of products improves greatly, has limited this product in industrial being extensive use of.At present on the inconsistent problem at carbon steel-water heat pipe and water, the method for employing has two kinds: a kind ofly use the chemical liquids passivation in the carbon steel tube wall, promptly at steel pipe inwall generation one deck tri-iron tetroxide passivating film, the while also can add corrosion inhibiter in working solution; Another kind is a valve of loading onto row's hydrogen at the cold junction of heat pipe, discharges non-condensing gas termly.More than two kinds of methods all undesirable; Add corrosion inhibiter in passivation and the working solution, though can make hydrogen generation speed reduce by 10 ³-10 ⁶Doubly, make carbon steel-water heat pipe can normally use about 3 years usually, but still can not satisfy long-life requirement of industrial heat exchanging device.

Because the unstability of passivating film, along with long use, can accumulate the hydrogen of non-condensing in the pipe more and more, in order to overcome the shortcoming that above-mentioned technology exists, purpose of the present invention, on the basis of existing chemical liquids passivating technique, provide a kind of and hydrogen generation rapid-action dehydrogenation complexing agent, the hydrogen of non-condensing can constantly be removed rapidly, thereby the carbon steel-water heat pipe working life is prolonged greatly, use this heat exchanger cheaply that the reliable technique assurance is provided widely for industrial.

Carbon steel pipe inwall with the chemical agent passivation, formed the film of layer of even tri-iron tetroxide, though this film can stop the electrochemical reaction of water and steel preferably, but because this film still has trickle slit, still can make sub-fraction carbon steel and water that the chance that contacts is arranged, thereby chemical reaction should take place at the hydrogen and the ferriferrous oxide film of the cold junction (upper end) of heat pipe more than 180 ℃ in generation hydrogen:

, hydrogen is eliminated.But in the practical application; because cold junction temperature can not remain on (temperature of heat pipe is generally at 80-250 ℃) more than 180 ℃; make above-mentioned chemical reaction carry out very slowly, moreover ferriferrous oxide film is limited in the amount of cold junction, obviously only depends on passivating film not reach tangible dehydrogenation effect.Therefore the more effective dehydrogenation agent of also essential increase, new dehydrogenation agent must possess following condition: (1) in carbon steel-water heat pipe normal working temperature scope (80-250 ℃) can not decompose voluntarily, but easily by hydrogen reduction; (2) the reduction afterproduct nontoxic, do not have corrosion, and do not influence the operate as normal of heat pipe; (3) do not react with water and steam; (4) obtain low price easily.Based on above-mentioned consideration and a large amount of scientific experiment research, it can be the compound dehydrogenation agent of Main Ingredients and Appearance with CuO with the hydrogen rapid-action that the present invention has selected for use more than heat pipe minimum operating temperature (80 ℃), and satisfies above-mentioned condition fully.Carbon steel-water heat pipe hydrogen removing agent of the present invention is the compound powder column of a kind of dehydrogenation, and its composition (weight) is:

CuO????65-81%

Cu????15-25%

Fe ₂O ₃4-10%

The compound powder column of dehydrogenation of the present invention is produced by following processing step: the CuO(purity 99.0%, 50～100 orders that at first take by weighing powdery by above-mentioned ratio of components), Cu(purity more than 80%, 100 orders) Fe ₂O ₃(purity more than 90%, 50～100 orders) mixing is with the medicinal powder that mixes, in the powder column mould that design processes in advance, with mixed powder compression molding, briquetting pressure 6-8Kg/cm ², then with in type compound powder column under 600-760 ℃ of temperature, sintering 15-35 minute, after the taking-up, cooling promptly obtained the compound powder column of dehydrogenation that uses in the heat pipe naturally.With the compound powder column of prepared dehydrogenation, be placed on the termination of the carbon steel-water heat pipe condensation end after the chemical passivation technical finesse then, this carbon steel-water heat pipe promptly has better dehydrogenation effect, thereby improves greatly its heat exchange performance and service life.

The compound powder column of dehydrogenation of the present invention better consist of CuO72%, Cu18%, Fe ₂O ₃10%; Best group becomes CuO75%, Cu20%, Fe ₂O ₃5%.Our experiments show that the desirable dosage of the compound powder column of dehydrogenation of the present invention in heat pipe is 0.5-0.6 gram CuO/100cm ²Internal surface area.The external form of the compound powder column of dehydrogenation of the present invention can be in column type, star column type, the polygon prism type etc. any.But consider convenient processing and manufacture; Guarantee the intensity (not easy fracture) of powder column; Easy for installation and fixing factor such as difficulty or ease, still better with column type.When designing compound powder column mould, the length (L of its powder column _o) and diameter (d _o) scope should be:

d _o=1/2(d _Bore-d _{The topping up external diameter of pipe}) * (50-75%)

L _o＝ $\frac{\mathrm{<figure-callout\; id="1"\; label="W"\; filenames="931200164\_DRIMG1.png"\; state="\{\{state\}\}">W</figure-callout>}}{\frac{1}{4}\mathrm{\&pi;}{d}_0^{2}p}$ W: powder column quality P: grain density

According to the mould of the required compound powder column of dehydrogenation of above-mentioned parameter design different size carbon steel-water heat pipe, by making the compound powder column of the dehydrogenation that adapts with it through mold pressing, sintering with described mixed powder.The optimal sintering temperature of the compound powder column of making dehydrogenation of the present invention is 600-620 ℃, and sintering time is 20 minutes.

A large amount of experimental results show that, the carbon steel-water heat pipe of laying with the compound powder column of dehydrogenation of the present invention, its dehydrogenation effect is (Fig. 1) very obviously, its working life can reach 6-8 (use the accelerated test predication method: the Arrhenius curve), near or reach anticorrosion, the compatible performance of copper material heat pipe with working solution.In addition, because the compressive resistance of carbon steel tube wall is than the copper material height of equal thickness, so it more can adapt to higher serviceability temperature, characteristics such as carbon steel-water heat pipe is easy to process, with low cost in addition, its application prospect is extremely considerable.

Example 1

Take by weighing powdery CuO(99.0%, 100 orders) 72g, the Cu(85%100 order) 18g, Fe ₂O ₃(95%100 order) 10g mixes, and to obtain diameter be that 4-5mm is long be the cylindrical grain of 30mm in compression molding in mould (as Fig. 2), puts into stove 620 ℃ of sintering 20 minutes, takes out nature and cools off and obtain the compound powder column of dehydrogenation.

During use, be installed in the cold junction (Fig. 3) of heat pipe, used 4320 hours, the cold junction wall is not seen variation (Fig. 1).

Description of drawings:

The cold pipe temperature of Fig. 1-heat pipe with along the variation diagram (test period: 4320 hours) of pipe range

1 uses dehydrogenation complexing agent of the present invention

2 tube walls are through chemical passivation

3 without any processing

Fig. 2-processing powder column die drawing

1 depression bar end

2 mould stamens

3 pressure

The compound powder column of Fig. 3-dehydrogenation is at the scheme of installation of heat pipe cold junction.

1 heat pipe topping up pipe

2 heat pipe cold junction heads

3 fixing powder column mount pads

The compound powder column of 4 dehydrogenations

5 hold-down screws

6 heat pipe wall

Claims (7)

1, a kind of carbon steel-water heat pipe hydrogen removing agent is characterized in that the compound powder column of a kind of dehydrogenation, and its composition (weight) is;

CuO???65-81%

Cu????15-25%

Fe ₂O ₃4-10%。

2, carbon steel-water heat pipe hydrogen removing agent as claimed in claim 1 is characterized in that the better composition (weight) of compound powder column is:

CuO????72%

Cu????18%

Fe ₂O ₃10%

3, carbon steel-water heat pipe hydrogen removing agent as claimed in claim 1 is characterized in that the best composition (weight) of compound powder column is:

CuO????75%

Cu????20%

Fe ₂O ₃5%

4, carbon steel-water heat pipe hydrogen removing agent as claimed in claim 1, the external form that it is characterized in that the compound powder column of dehydrogenation can be in column type, star column type, the polygon prism type any.

5, carbon steel-water heat pipe hydrogen removing agent as claimed in claim 1, the external form that it is characterized in that the compound powder column of dehydrogenation is column type preferably.

6, a kind of method of making the described carbon steel-water heat pipe hydrogen removing agent of claim 1 is characterized in that manufacturing process steps is CuO, Cu, the Fe that takes by weighing powdery by described ratio of components ₂O ₃Mixing is with the medicinal powder compression molding in the powder column mould that mixes, briquetting pressure 6-8kg/cm ², then with in type compound powder column at 600-760 ℃ of sintering 15-35 minute, take out the nature cooling.

7, the method for making carbon steel-water heat pipe hydrogen removing as claimed in claim 6 agent is characterized in that compound powder column is preferably in 600-620 ℃ of sintering 20 minutes.

Images