CN108455716A - For fertilizer production line upper circulation water cooling system good antiscale property method - Google Patents

Abstract

For fertilizer production line upper circulation water cooling system good antiscale property method, it is characterised in that：Good antiscale property method is as follows：A, sulfuric acid control loop water ph value 7.5 8.3 is dropped evenly to recirculated water;B, hardness≤7mmol/L or less of control loop water is drained by benefit；C, pH value 7.5 8.3 and hardness≤7mmol/L recirculated waters below temperature≤45 DEG C are controlled by temperature controller to squeeze on fertilizer production line in required equipment.Advantage of the present invention：The invention discloses one kind being used for fertilizer production line upper circulation water cooling system good antiscale property technology, avoid the fouling of circulating water cooling system completely using the technique, cooling equipment is also avoided because fouling needs cleaning during shutdown or there is a situation where the various influence productions such as leakage maintenance shut-downs, circulating water cooling system can be simultaneously reached water-saving purpose with long-period stable operation.And the process, investment is small, and operating method is simple, and principle easily-learned easily mastered can be widely popularized utilization.

Description

For fertilizer production line upper circulation water cooling system good antiscale property method

Technical field

The invention belongs to chemical production technical inventions, and in particular to be used for fertilizer production line upper circulation water cooling system anti-caking Dirty method.

Background technology

Fertilizer production line upper circulation water cooling system industrially uses extensive, circulation cooling equipment scaling, heat exchange effect Rate is low, equipment is because the fouling accident that occurs leaking and stop is very common, generally can largely drain to reduce recirculated water index and set It changes, circulation water consumption is big.The operation quality of circulation directly determines the safe and stable operation of master device, therefore Circulation prevents from fouling and reduces water consume to be a problem in urgent need to solve.

Invention content

The purpose of the present invention provides aiming at current above-mentioned deficiency and is used for fertilizer production line upper circulation water cooling system anti-caking Dirty method.

The method of the present invention is as follows：

A, sulfuric acid, control loop water ph value 7.5-8.3 are dropped evenly to recirculated water;

B, hardness≤7mmol/L or less of control loop water is drained by benefit；

C, pH value 7.5-8.3 and hardness≤7mmol/L recirculated waters below temperature≤45 DEG C are controlled by temperature controller to beat Enter on fertilizer production line in required equipment.

Advantage of the present invention：The invention discloses one kind being used for fertilizer production line upper circulation water cooling system good antiscale property technique skill Art avoids the fouling of circulating water cooling system using the technique completely, also avoids cooling equipment because fouling needs cleaning during shutdown Or there is a situation where the various influence productions such as leakage maintenance shut-downs, circulating water cooling system can be with long-period stable operation, together When can reach water-saving purpose.And the process, investment is small, and operating method is simple, principle easily-learned easily mastered, Ke Yiguang It is general to promote the use.

Specific embodiment

The present invention is as follows：

A, sulfuric acid control loop water ph value 7.5-8.3 is dropped evenly to recirculated water;

B, hardness≤7mmol/L or less of control loop water is drained by benefit；

C, pH value 7.5-8.3 and hardness≤7mmol/L recirculated waters below temperature≤45 DEG C are controlled by temperature controller to beat Enter on fertilizer production line in required equipment.

1. using the sulfuric acid control loop water ph value 7.5-8.3 for dropping evenly no objectionable impurities to circulating water pool, inhibit to follow The process of the concentration of bicarbonate ion in ring water.

2. using the technic index of control cooling equipment leaving water temperature≤45 DEG C, bicarbonate ion is inhibited to be thermally decomposed For lime deposit and carbon dioxide gas, sediment is prevented（Dirt）With the generation of carbon dioxide gas.

3. circulation suitably mends draining, hardness≤7mmol/L of control loop water is hereinafter, control cycles of concentration and suppression The concentration of calcium ions and magnesium ions in recirculated water processed reduces the concentration of calcium bicarbonate and magnesium bicarbonate.

Production technology of the present invention is the base for normally adding corrosion inhibiting and descaling agent and sterilization algae removal medicament in circulation On plinth, by studying recirculated water fouling mechanisms, finding recirculated water fouling the main reason for is presence because of bicarbonate ion, In the continuous cyclic process of recirculated water, water can react as follows with the carbon dioxide in air：H₂O+CO₂→HCO3^-, bicarbonate Radical ion is combined with calcium ions and magnesium ions, generates calcium bicarbonate and magnesium bicarbonate molecule, and calcium bicarbonate and magnesium bicarbonate are highly unstable, It is heated to be decomposed into calcium carbonate and magnesium carbonate and carbon dioxide, chemical formula Ca（HCO3）₂ CaCO₃ +CO₂, calcium carbonate and carbonic acid Magnesium will adhere to precipitation on heat transmission equipment surface and form dirt, when carbon dioxide gas exchanges heat by cooling column air pump, the quilt from water Cold wind is brought into atmosphere, and the acidity of recirculated water declines, and pH value can rise, and pH value, which can rise, can lead to the dense of bicarbonate ion Degree rises, and can produce more calcium bicarbonates and magnesium bicarbonate, these calcium bicarbonates and magnesium bicarbonate again can be in heat exchanger surfaces Fouling, with the extension of time, dirt can be more and more, the pH value of recirculated water can be higher and higher, and water temperature also can be higher, cooling tower Evaporation capacity is bigger, and general interference method is to reduce circulating water PH value and hardness, quantity of exchanged water is very using the method for largely changing water Greatly.This is also the big reason of recirculated water water consumption.If equipment fouling, even if largely cooling equipment can not be alleviated by changing water The problem of fouling, because the water pipe circulation area after fouling becomes smaller, water becomes smaller, and the water temperature after exchanging heat is just high, calcium bicarbonate Decomposition can be connected and generate calcium carbonate scaling.Therefore it is controlled using following process from fouling mechanisms：

1, sulfuric acid is added into circulating water pool for continuous uniform, adjusts pH value 7.5-8.3, and alkalinity of water is recycled when PH controls normal also not Good height.It is Corrosive water quality less than 7.5 or less, non flouling behaviour, but to equipment, there are acid corrosions.It is fouling tendency water quality higher than 8.3, Bicarbonate ion concentration is high, and equipment scaling probability increases at geometry multiple.（If there is particular factory is in sour gas environment In, water is for a long time acidity, then needs plus alkali is adjusted）.Control is optimum range in 7.5-8.3, makes recirculated water between corrosive water Between matter and fouling tendency water quality, corrosion and fouling are avoided the problem that.Circulating water pool is equipped with online PH detectors, continuous uninterrupted Detection circulating water pool in pH value, PH instrument wants periodic check.

2, leaving water temperature≤45 DEG C of control loop water heat transmission equipment.When equipment leaving water temperature is higher than 45 DEG C, calcium bicarbonate It can be thermally decomposed with magnesium bicarbonate, generate calcium carbonate and magnesium carbonate sediment fouling, while the corrosivity gas that splits the carbon dioxide off Body is finally taken out of by wind to atmosphere on cooling tower top.Water temperature height also illustrates that heat exchange water is inadequate or circulating water temperature is high, Adjustment water or water temperature in time inhibit calcium bicarbonate and bicarbonate finally within the scope of leaving water temperature≤45 DEG C of heat transmission equipment Magnesium can be thermally decomposed.Thermometer is installed in cooling equipment water outlet, continuously monitors temperature on-line.

1, draining, the control loop water hardness and cycles of concentration are mended by recycling hydrologic(al) budget.The purpose of draining is control loop The water hardness and cycles of concentration are basicly stable, avoid hardness and the fluctuating range of cycles of concentration.Recirculated water heat exchange load can be adopted again With draining for every eight hours, daily draining gently may be used in heat exchange load, but the tonnage drained wants balanced, using per tour or daily row The tonnage of water wants of substantially equal, and water examination interval time wants balanced, and final purpose is to recycle the water hardness in control operational process It is basicly stable with cycles of concentration.Drainpipe will install flowmeter and be measured, and amount as required is drained.

2, when circulation thermic load is big, circulating water temperature is high, and heat transmission equipment leaving water temperature times is more than so after increasing water At 45 DEG C, in order to avoid fouling, circulating water PH value can be reduced, pH value is close to 7.5, but should not be low by adjusting acid adding amount In 7.5, the total amount that bicarbonate radical and calcium bicarbonate and magnesium bicarbonate decompose thus is reduced as far as possible, reduces knot to greatest extent Dirt, equipment can also extend service life.On the contrary when circulation thermic load is low, cycle coolant-temperature gage is low, the water outlet of heat transmission equipment When temperature is less than 40 DEG C or less, pH value can be close to 8.3, but not surpass 8.3, and economically considering can be circulating water temperature Degree properly increases, and operation during this period is also safety.

3, since the benefit for controlling the PH of cycle water, the leaving water temperature of heat transmission equipment therefore circulation drains purpose It is very clear, it is exactly the cycles of concentration and total hardness of control loop water.General displacement can be than using large excretion and large complement mode control The circulation using water wisely about 70% or more of system.For example, by using process above, 200,000 tons of sulphur-burning sulphuric acid plant, cycle Big hundredweight of water system displacement or so/day；200000 tons of pyrite concentrate sulphuric acid plant, about 150 tons or so/day of displacement.Such as Fruit does not use process above, 200,000 tons of sulphur-burning sulphuric acid plant, about 500 tons or so/day of displacement；200000 tons of pyrite concentrate system Sour device, about 700 tons or so/day of displacement, water consumption are larger.

Claims (1)

1. being used for fertilizer production line upper circulation water cooling system good antiscale property method, it is characterised in that：Good antiscale property method is as follows：

A, sulfuric acid control loop water ph value 7.5-8.3 is dropped evenly to recirculated water;

B, hardness≤7mmol/L or less of control loop water is drained by benefit；

C, pH value 7.5-8.3 and hardness≤7mmol/L recirculated waters below temperature≤45 DEG C are controlled by temperature controller to beat Enter on fertilizer production line in required equipment.