Upgrading the pump, replacing the mechanical seal and improving the pump performance мақала

Upgrading the pump, replacing the mechanical seal and improving the pump performance

Khurmankhan Maral

maral1001@bk.ru

teacher, Pavlodar chemical and mechanical college, city of Pavlodar, Kazakhstan

Umurzakova Sabina Beibitovna

umurzakovasabina@mail.ru

teacher, Pavlodar chemical and mechanical college, city of Pavlodar, Kazakhstan

Omarbekova Inara Kasymkhanovna

inara_19@mail.ru

teacher, Pavlodar chemical and mechanical college, city of Pavlodar, Kazakhstan

Annotation:The article deals with issues related to replacing the mechanical seal of the h-004 pump. In many ways, single end seals will wear out from mechanical impurities, and if they are not properly used, which slow down the process and can allow products to leak.

The purpose of this work is to eliminate the pulverization of a small fraction of the pumped product , which occurs in the operation of the pump in petrochemical processes.

Keywords: centrifugal pump, mechanical seal, sealing.

In the presidential address “Kazakhstan 2050”, country leader N. A. Nazarbayev underlined that the oil and gas complex of Kazakhstan is a locomotive for the entire economy and contributes to the development of other industries, that an effective oil and gas sector of the economy should be created. Due to the development of the share of the country's oil and gas industry has grown over the past 5 years from 14.7% to 25.8%, which indicates the stable growth dynamics of the oil and gas industry.

Pavlodar petrochemical plant is the largest enterprise in Kazakhstan for the production of petroleum products. MLP "PNHZ " is the only enterprise in Kazakhstan with a set of technological installations that provides deep processing of oil up to 85%, which corresponds to the level of the best producers of petroleum products.

Today, the main goal of the Pavlodar petrochemical plant is producing demanded products in the volume necessary for the needs of the country and corresponding to the requirements of the world market. The main way to achieve this goal is creating a modern production base as a result of modernization and technical re-equipment of existing production, as well as the construction of new high-tech facilities.

The Isomerization process Unit and Naphtha Splitter are an integral part of the plant's production. The isomerization unit and Naphtha Splitter is used to produce commercial naphtha with an octane number not lower than 88.5, which is a high-octane component of gasoline AI-92-K2, AI-95-K2, as well as light and heavy naphtha for further refinements.

Pumping equipment plays a very large and important role in the life of the plant. Correct and unyielding operation of pumping equipment is an indispensable factor in the operation of the entire installation, which allows us to learn the importance of maintenance, installation and proper operation of pumps.

The object of research is a cantilever centrifugal pump N-004 of the USP40-380 type of isomerization unit and a naphtha Splitter.

Pumps are hydraulic machines that convert the mechanical energy of the drive motor into the energy of the fluid flow, which serves to move and supply all types of liquids. According to the principle of operation, there are: centrifugal , rotary, piston, screw, and there are also special pumps. These include: electromagnetic, pneumatic, and so on.

Centrifugal pumps are units consisting of a shell in the form of a snail and an electric motor, connected by a gear coupling and mounted on a common Foundation plate, which have suction and discharge pipes. The main working body is the impeller mounted on a shaft that is connected to the electric motor via a plate coupling.

In our time, oil and gas equipment failure often occurs, at this stage, consider the horizontal cantilever single-stage centrifugal pump H-004 model USP40-380 isomerization unit and naphtha Splitter. Pump N-004 model USP40-380, technological position A100-N-004A, is designed for the circulation of alkali in the K-002 column.

Main parts of the centrifugal pump

The lion's share of all pumps produced in the world are console pumps of various types and designs. According to experts published at various times in specialized publications related to pumping topics, the number of console pumps in pieces is from 59 to 72% of the total fleet of pumps produced in the world. This figure is due to the simple design of the cantilever pump compared to other types of pumps. The elementary principle of the cantilever pump ensures its wide distribution both in municipal equipment and in complex liquid supply systems of military equipment and spacecraft.

Console pumps have long proven themselves only on the positive side. Their external simplicity bribes the future owner. But behind this simplicity lies a universal device that is ready to perform any tasks. The cantilever pump is designed for pumping liquid in both cold and hot conditions. An important and distinctive feature is that the composition of the pumped liquid may include impurities. Their concentration should not exceed 0.1%. Given the relatively high productivity, this figure is actually very high. The size of some solid particles is limited to 0.2 mm.

An alkaline NaOH solution from the bottom of the K-002 column is fed to the suction of the h-004A/B alkali circulation pumps. After pumping the pumps, passing the heater T-012, the alkali is distributed into two streams. The first flow is supplied from above the bottom of the nozzle where the dry gas is washed with an alkaline solution, the second stream is fed below the bottom part of the bottom nozzle of the column to the spray nozzle to protect the column from contact with corrosive gas by washing the walls of the scrubber an alkaline solution.

The temperature of the alkali at the outlet of the heater T-012 is controlled by the device POS. TIA-0096.

If the concentration of the circulating alkaline solution decreases below 2% (wt.) NaOH, the spent alkali from the h-004A pumps/B is sent to the waste alkali degassing tank E-009.

Our idea is to replace a single mechanical seal with a double mechanical seal. Why at this time, from this pump through water flushing come out in small fractions of alkali? The answer is as follows: since we know that a centrifugal cantilever pump when pumping an alkaline solution has mechanical impurities in the composition of the product being pumped.

Currently, the cantilever type of centrifugal pumps is considered the most advanced in the field of high performance.Among the total volume of pumping equipment produced, console-type pumps account for 65 %. These units have gained popularity due to their very simple design, ease of repair and maintenance, and fairly high efficiency.

By its design, the cantilever pump is a type of centrifugal pump, which is characterized by the presence of a working centrifugal wheel.

The main advantages of the cantilever pump housing design, which allows installation of the pressure pipe vertically and horizontally, are the following:

- direct attachment of the flanged motor to the pump body (provides the least impact of vibration on the structure);

- the presence of a mechanical seal, independent of the direction of rotation (provides ease of operation);

- the possibility of quick start and fast stop of the pump operation;

- high characteristics of vibroacoustics (reduced noise level).

Based on the General situation and based on the totality of all the above-mentioned facts, we can determine: when pumping the product, a single mechanical seal does not sufficiently seal the pumping medium, and replacing the double mechanical seal will eliminate the pulverization of a small fraction of the alkaline solution.

Based on the evidence, we can draw the following conclusion. Double mechanical seal is the best replacement for improved performance and impermeability through o-rings.

The double mechanical seal will last much longer, since the new SBTU cooling system will be operated during the water wash process and will perform more thorough sealing, as well as deep cooling and detailed lubrication. The seal will allow the pump to operate for a long time.

List of sources used

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2. Dunton T.A. An Introduction to Time Waveform Analysis. / T.A. Dunton. – Universal Technologies. – 1999. P. 120 – 128.

3. Jones C.M. Pumping station design / С. M. Jones. - Pumping station design. – 2006. P. 20 – 24.

4. Ryndin V. V. Application of the Mathcad system for static analysis of experimental data / V. Ryndin, Yu. Volkova / / Science and technology of Kazakhstan. - 2008. Р. 95.

5. Perevoschikov S. I. Reduction of hydrodynamic vibration of centrifugal pumps.– 1997. P. 50–56.