CN108585227A - A kind of high-temperature sulfuric acid calcium type Brine pre -heater surface antiscaling method - Google Patents

Abstract

The invention discloses a kind of high-temperature sulfuric acid calcium type Brine pre -heater surface antiscaling methods, it is characterised in that is achieved by the following technical programs：10.3 12.5g/L dead plasters are added in the brine for needing high temperature preheating as crystal seed；It is preheated by the way of heating up step by step, heating rate is 2~4 DEG C/min, and it is 0.130 0.170kg/s to control mass flow；Optimum experimental, the stringent run time for controlling heat transmission equipment.Present invention incorporates the crystal forms of calcium sulfate under hot conditions to have achieved the purpose that prevent calcium sulfate type brine high temperature preheating fouling using temperature programming while the run time of stringent control device.

Description

A method for preventing scaling on the surface of a high-temperature calcium sulfate type brine preheater

technical field

The invention relates to a method for preventing fouling of a preheater in the process of preheating calcium sulfate type brine at high temperature, and belongs to the field of sea brine resource development.

Background technique

The solubility of calcium sulfate belongs to inverse solubility. Under high temperature conditions (above 100°C), the solubility of calcium sulfate is relatively low, and a certain amount of calcium sulfate is contained in calcium sulfate type brine, so the scaling problem of calcium sulfate is in heat exchange. The equipment is relatively prominent. The calcium sulfate type of calcium scale is characterized by rapid scaling and hard texture. It is not easy to remove by pickling and mechanical descaling. On the other hand, scaling seriously affects the heat exchange efficiency of heat exchange equipment. Research Calcium sulfate type brine high temperature preheating anti-scaling problem is of great significance to solve the scaling of heat exchange equipment.

At this stage, the methods for calcium sulfate anti-scaling are mainly divided into chemical methods and physical methods. The chemical anti-scaling method is to use the chemical properties of the chemical anti-scaling agent itself to prevent or slow down the formation of scale. The current chemical anti-scaling method is mainly the softening method. , acidification method, and antiscalant methods. However, chemical antiscaling has many disadvantages. At present, antiscalants mainly contain phosphorus, which can easily cause eutrophication of water bodies. At the same time, the cost of antiscalants is relatively high. The best way to prevent scale is to choose non-polluting physical methods to prevent scale, but the general magnetic treatment, ultrasonic and other methods have poor scale inhibition effect on calcium sulfate type calcium scale. Calcium sulfate mainly has three different crystals due to the influence of temperature, etc. The crystal form of water, and the scaling of calcium sulfate is particularly serious under high temperature conditions. The current anti-scaling method of seed crystal method does not take into account the crystal form of calcium sulfate. Generally, gypsum is used as the crystal seed, which is suitable for the transportation of calcium sulfate-type brine at low temperature, and cannot achieve scale inhibition effect at high temperature. , but will aggravate calcium sulfate scaling. Studying the antiscaling effect of different crystal forms of calcium sulfate as seed crystals has important guiding significance for the antiscaling of calcium sulfate brine high temperature preheating.

Contents of the invention

The technical problem to be solved by the present invention is that the high temperature (above 100°C) of calcium sulfate type brine is serious in anti-scaling and lack of high-efficiency cleaning technology, the loss of heat exchange equipment is serious, and the heat exchange efficiency is low. Solve the preheating of calcium sulfate type brine from the source scaling problem.

The present invention is achieved through the following technical solutions:

(1) Add 10.3-12.5g/L anhydrous calcium sulfate as crystal seed in the brine that needs high temperature preheating;

(2) Preheating is carried out by means of step-by-step heating, the heating rate is 2-4°C/min, and the mass flow rate is controlled at 0.130-0.170kg/s;

(3) Experimental optimization, strictly control the running time of heat exchange equipment.

The beneficial effect of the invention is that it can remarkably reduce the preheating fouling amount of calcium sulfate type brine under high temperature conditions.

Detailed ways

The present invention will be further described in detail below in combination with specific embodiments.

Example 1:

Using calcium sulfate brine in Feicheng as raw material, a detachable small tube heat exchanger is used to exchange heat for calcium sulfate brine. For seed crystals, the mass flow rate of the brine is 0.164kg/s, and the temperature of the brine is heated to 120°C at a speed of 2°C/min. After 30 days of operation of the tube-and-tube heat exchanger, the test showed that the temperature of the last tube dropped by 0.5°C. Disassemble the detachable tube-and-tube heat exchanger to observe the fouling of the tube-and-tube heat exchanger. The heater has only a thin layer of rough yellow calcium scale,

Example 2:

Using calcium sulfate brine in Feicheng as raw material, a detachable small tube heat exchanger is used to exchange heat for calcium sulfate brine. For seed crystals, the mass flow rate of the brine is 0.152kg/s, and the temperature of the brine is heated to 120°C at a speed of 3°C/min. After 25 days of operation of the tube and tube heat exchanger, the test shows that the temperature of each tube of the tube and tube heat exchanger does not change. Disassemble the detachable tube and tube heat exchanger to observe the fouling of the tube and tube heat exchanger, and it can be observed that The tube heat exchanger basically does not have fouling,

Example 3:

Using Feicheng calcium sulfate brine as raw material, a detachable small tube heat exchanger is used to exchange heat and heat up calcium sulfate brine. Test conditions: add anhydrous calcium sulfate as a crystal seed in brine at a temperature of about 103°C to ensure The content of calcium sulfate seed crystals in the brine is 10.3g/L, the mass flow rate of the brine is 0.131kg/s, and the temperature of the brine is heated to 119°C at a speed of 4°C/min. After 26 days of operation, the test shows that , The temperature of each tube of the tube-and-tube heat exchanger does not change much. Disassemble the detachable tube-and-tube heat exchanger to observe the fouling of the tube-and-tube heat exchanger. It can be observed that there is basically no scaling in the tube-and-tube heat exchanger.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the methods and principles of the present invention shall be included within the protection scope of the present invention.

Claims (1)

1. a kind of high-temperature sulfuric acid calcium type Brine pre -heater surface antiscaling method, it is characterised in that include the following steps：

(1) 10.3-12.5g/L dead plasters are added in the brine for needing high temperature preheating as crystal seed；

(2) it is preheated by the way of heating up step by step, heating rate is 2~4 DEG C/min, and it is 0.130- to control mass flow 0.170kg/s；

(3) optimum experimental, the stringent run time for controlling heat transmission equipment.