Vacuum pump in vacuum metallurgy

Each work of vacuum metallurgy needs to meet a certain degree of vacuum, and the requirements for different degrees of vacuum are also different.liquid_ring_vacuum_pump

Nowadays, a variety of pumps have been produced, which are constructed according to different pumping principles. They have different characteristics and reach different starting and stopping pressures, which is suitable for a certain range of pressures.rotary-vane-vacuum-pump-vacuum-thermoforming

Since the various pumps reach different pressures, the two or more pumps can be matched to meet the needs when the working pressure is low.

The gas generated in vacuum metallurgy may contain different substances, such as dust, fine metal particles, water vapor, volatile organic compounds, harmful gases, etc., and appropriate measures should be added to the pump or piping system to ensure smooth pumping and pump operation. Good, long life and no impact on the environment.rotary-vane-vacuum-pumps

Roots vacuum pump in paper mill

In small and medium-sized paper mills, most of them use low-speed small paper machines. For example, 1092 single cylinder (double cylinder) round wire machine, 1575 round mesh double cylinder paper machine, 1575 short net double cylinder paper machine, 1575 long net multi-cylinder paper machine, 1760 long net multi-cylinder paper machine. Most of the vacuum pumps that these paper machines used in the past were water ring pumps. With the advancement of technology, energy conservation and environmental protection, in the past ten years, the Roots vacuum pump and the Roots pump have been widely used in the vacuum system of paper machines at home and abroad. Satisfactory results can be obtained by matching the specifications of the machine with the relevant technical requirements of the paper type.rotary_vane_vacuum_pump

The choice of Roots vacuum pumps in the vacuum system of paper machines is based on several reasons:

(1) The effect of vacuum on the pumping speed and paper dryness of different quantitative papers The vacuum degree requirements of different quantitative paper sheets under different dryness. For example, when the basis weight is 24 g/m2, in order to obtain a dryness of 13%, the degree of vacuum must be 160 mmHg, and similarly, when the basis weight is 30 g/m2 and 65 g/m2, a dryness of 15% and 20%, respectively, is obtained. The degrees must be 200 mmHg and 450 mmHg, respectively. As this increases the thickness of the sheet due to the quantitative increase, it is necessary to increase the dryness in order to increase the wet strength of the wet sheet.vacuum-pump-vacuum-thermoforming

(2) Requirements for vacuum system according to the papermaking process From the working characteristics and characteristic curves of the ZBK11 wet four-leaf Roots vacuum pump, it can be clearly seen that the vacuum is in the range of 250-550 mmHg, and the curve is horizontal, and its essence is The pumping capacity of the pump remains essentially the same.

(3) Economical effect of using Roots vacuum pump The performance characteristics of Roots vacuum pump and water ring pump have been described in the previous chapters. What about the economic and technical benefits of the Roots pump and the water ring pump? This is also a concern of the paper industry. Take the practice of paper mills as an example to illustrate the following issues:

Roots vacuum pumps save energy. The Roots vacuum pump is highly efficient and is not generally comparable to a water ring vacuum pump. Rather, it means that the power consumed per unit of pumping capacity (so-called specific power) in the high efficiency zone (with a vacuum in the range of 100-200 mmHg) is much lower than that of the water ring pump. The reason is that the high-efficiency zone of the water ring pump is in the range of 400 mmHg of vacuum. In the paper machine net parts and felts similar to the factory, the vacuum requirements are less than 400mmHg, so the use of the Roots pump is the strength of the pump.Roots_Vacuum_Pump

Roots Vacuum Pump for Sale

The temperature rise of Roots vacuum pump refers to the difference between the highest temperature and room temperature measured in all parts of the pump exterior under the condition of stable operation of the limit vacuum or rated vacuum. The types of thermometers used to measure temperature rise are not limited, but they should have the measurement accuracy of <1 C. When marking the temperature rise, it should also indicate the room temperature at that time, the cooling conditions of the pump, including cooling methods, such as water cooling should indicate the temperature of the inlet and outlet water.vacuum-pump-in-vacuum-filtration

The outlet pressure of Roots vacuum pump refers to the pressure of measuring the jacket near the exhaust port corresponding to a certain inlet pressure value under the condition of stable operation of Roots vacuum pump. The outlet pressure can be measured at the same time as the pumping rate, starting from the appropriate value close to the limit vacuum until about the allowable inlet pressure of the pump. Measure the outlet pressure corresponding to each inlet pressure value.liquid_ring_vacuum_pump

The measuring position of the outlet pressure is specified in the standards issued by the Ministry. The distance between the pressure measuring tube and the flange of the pump outlet should not be greater than the diameter of the pump outlet, and the opening plane of the pressure measuring tube should be parallel to the direction of the airflow. The insertion depth is 1/4 d, but not greater than 50 mm.rotary-vane-vacuum-pumps

Vacuum Pump for Vacuum Furnace

To ensure high vacuum, besides reliable gas tightness and vacuum pipeline of furnace, appropriate vacuum pump equipment is also needed.vacuum-pump-paper-industry

The requirement of vacuum pump is put forward according to the condition of reducing period. After the pressure block is installed in the furnace and the furnace is closed, the air in the furnace must be extracted. Then, as the charge is heated, the inhaled and combined gases (water vapor and carbon dioxide) are separated from the briquette. When these gases precipitate at higher temperatures, they can greatly increase the blast furnace pressure and destroy the vacuum process, even in small quantities. In addition, when carbon dioxide and water vapor rush into hotter areas, gram reacts with silicon and precipitated water vapor. Therefore, it is necessary to ensure the rapid and full extraction of the released gas.Roots_Vacuum_Pump

Therefore, the vacuum pump should complete the following tasks: first, to ensure that a large number of gases are pumped out under normal pressure at the beginning of the cycle; second, to maintain a considerable gas extraction speed under low pressure throughout the operation cycle.rotary_vane_vacuum_pump

Liquid ring vacuum pump in vacuum conveying

The vacuum suction solid device is mainly composed of a nozzle, a feed pipe, a separator, a gas pipe, a dust remover and a vacuum pump.Roots_Vacuum_Pump

The liquid ring vacuum pump sucks solid powder materials and is characterized by reliable operation, simple structure, convenient operation and low noise. Since water is used as a medium, even if the air contains a small amount of dust, it enters the vacuum pump and is mixed with water, and is often discharged from the vent hole along with the water, and the wear on the pump is small. In addition, the particularly outstanding feature is that its working characteristic curve and suction process requirements are relatively close, which can ensure the smooth operation of the suction.vacuum-pump-system-in-metal-casting

When the degree of vacuum changes from 0 to 60%, the gas volume changes only between 695 and 616 m8/hour, and the rate of change is only 11.4%. Such a small change can satisfy the suction requirement.rotary_vane_vacuum_pump

In the vacuum suction, three kinds of liquid ring vacuum pumps are commonly used.

liquid ring vacuum pump by vacuum distillation

Correct Use of Cooling Tower and Cooling Condenser of Liquid Ring Vacuum Pump

We all know that the liquid ring vacuum pump usually uses water as working fluid, in the process of water suction and discharge to achieve the purpose of vacuum pumping. In the process of water suction and dispatch, because water strikes the pump wall, impeller and disc to do work and generate heat. If we continuously use water to suck in and drain out water, it will not produce water ring pump because of the increase of working fluid temperature. Vacuum decreases, but in many cases water or other working fluid is needed to be recycled. At this time, cooling towers or condensers are needed to make the liquid ring vacuum pump work normally.rotary-vane-vacuum-pumps

Cooling tower is a heat dissipation device, which uses the principle of evaporation and heat absorption of water to dissipate waste heat generated in industry or refrigeration and air conditioning to ensure the operation of the system. It can reduce the temperature of cooling water. Using this principle, we can solve the problem that the circulating liquid temperature of the liquid ring vacuum pump keeps rising and the vacuum degree is reduced. In the drainage port of the liquid ring vacuum pump, we connect a pipeline to the cooling tower, which reduces the temperature of the water by cooling the tower, and then let the water flow into the storage tank or pool so that the temperature of the circulating liquid can be controlled during the continuous working process of the liquid ring vacuum pump, thus solving the problem of the vacuum reduction of the liquid ring vacuum pump due to the increase of the temperature of the circulating liquid.liquid_ring_vacuum_pump

In the process of vacuum distillation or vacuum cooling, because the temperature of the exhausted gas is too high, the temperature of the liquid ring vacuum pump will rise, which will reduce the vacuum degree of the liquid ring vacuum pump, so we need to connect a condenser to the inlet of the liquid ring vacuum pump. After cooling, the temperature of the gas will decrease, and then it will be pumped into the liquid ring vacuum pump, which will solve the problem of vacuum drop caused by excessive temperature.roots-vacuum-pump-for-vacuum-casting

Vacuum Pump in Coal Mine

The vacuum pump used in coal mine is 2BV water ring vacuum pump. The maximum vacuum obtained is 3300 Pa. The pump can be started in tens of seconds. The drainage arrangement is shown in Figure 1. The water ring vacuum pump is an axial single-acting structure, the impeller and the pump body are installed relatively eccentrically. Therefore, when the impeller rotates, the water is thrown around by the impeller. Because of the centrifugal force, the water forms a closed water ring which is approximately equal thickness depending on the shape of the pump chamber. The inner surface of the upper part of the water ring is just tangent to the impeller wheel, and the inner surface of the lower part of the water ring is just right to the top of the blade. Contact (actually the blade has a certain insertion depth in the water ring). A crescent-shaped space is formed between the impeller wheel and the water ring. According to the blade, the impeller is divided into several closed chambers with different volume, which rotate with the impeller.liquid_ring_vacuum_pump


If the upper part of the impeller is used. As a starting point, the volume of the small chamber increases from small to large when the impeller rotates 180 degrees, and is connected with the suction port on the end surface. At this time, the gas is absorbed, and at the end of the suction, the small chamber is isolated from the suction port. When the impeller continues to rotate, the small chamber becomes smaller and compresses the gas; when the small chamber is connected with the exhaust port, the gas is discharged out of the pump. The suction pipe of the vacuum pump is connected with the first stage pump housing of the main pump. The drainage pipe of the vacuum pump guides the water in the pump room ditch. The water sealing pipe of the vacuum pump continuously supplies water to the vacuum pump for sealing, and a one-way valve is installed on the discharge pipe of the balance chamber. Before starting the pump, open the valve and then start the vacuum pump. At this time, the solenoid valve opens automatically and fills the pump. Four mine water pumping houses have designed a wall 1 m3 water tank for vacuum pump irrigation.rotary-vane-vacuum-pumps

2BV water ring vacuum pump can achieve centrifugal pump without bottom valve drainage, need to set up water tank, artificial irrigation, water demand is not much, but the vacuum pump and motor to occupy the ground area, and one with one. The start-up time of the two pumps is also different. Each mine can choose freely according to the actual situation, which can achieve economic operation, high efficiency and energy saving, and meet the requirements of (design code for underground drainage in coal mine).liquid-ring-vacuum-pump-for-food-processing