scholarly journals XXV. On the thermal effects of fluids in motion.— Part IV

1862 ◽  
Vol 152 ◽  
pp. 579-589 ◽  
Keyword(s):  
High Pressure ◽  
Thermal Effects ◽  
Carbonic Acid ◽  
Low Pressure ◽  
Cooling Effect ◽  
Porous Plug ◽  
Pressure Side ◽  
Atmospheric Air ◽  
Elastic Fluid ◽  
The Difference

In the Second Part of these researches we have given the results of our experiments on the difference between the temperatures of an elastic fluid on the high- and low-pressure sides of a porous plug through which it was transmitted. The gases employed were atmospheric air and carbonic acid. With the former, 0°·0176 of cooling effect was observed for each pound per square inch of difference of pressure, the temperature on the high-pressure side being 17°·25. With the latter gas, 0°·0833 of cooling effect was produced per lb. of difference of pressure, the temperature on the high-pressure side being 12°·844. It was also shown that in each of the above gases the difference of the temperatures on the opposite sides of the porous plug is sensibly proportional to the difference of the pressures.

scholarly journals III. On the thermal effects of fluids in motion

1860 ◽  
Vol 10 ◽  
pp. 502-502
Keyword(s):  
Thermal Effects ◽  
Carbonic Acid ◽  
Cooling Effect ◽  
Porous Plug ◽  
Heating Effect ◽  
New Apparatus ◽  
The Difference ◽  
The Government ◽  
Government Grant ◽  
Elastic Fluids

In our paper published in the Philosophical Transactions for 1854, we explained the object of our experiments to ascertain the difference of temperature between the high- and low-pressure sides of a porous plug through which elastic fluids were forced. Our experiments were then limited to air and carbonic acid. With new apparatus, obtained by an allotment from the Government grant, we have been able to determine the thermal effect with various other elastic fluids. The following is a brief summary of our principal results at a low temperature (about 7° Cent.). Further experiments are being made at high temperatures, which show, in the gases in which a cooling effect is found, a decrease of this effect, and an increase of the heating effect in hydrogen. The results at present arrived at indicate invariably that a mixture of gases gives a smaller cooling effect than that deduced from the average of the effects of the pure gases.

XXIII. On the thermal effects of fluids in motion. —Part IV

1863 ◽  
Vol 12 ◽  
pp. 202-202
Keyword(s):  
Thermal Effect ◽  
Thermal Effects ◽  
Low Pressure ◽  
Porous Plug ◽  
Atmospheric Air ◽  
The Difference ◽  
Two Sides

A brief notice of some of the experiments contained in this paper has already appeared in the ‘Proceedings.’ Their object was to ascertain with accuracy the lowering of temperature, in atmospheric air and other gases, which takes place on passing them through a porous plug from a state of high to one of low pressure. Various pressures were employed, with the result (indicated by the authors in their Part II.) that the thermal effect is approximately proportional to the difference of pressure .on the two sides of the plug.

Practical Considerations When Conducting a Transient Analysis of a Heat Exchanger Tube Rupture

2012 ◽  
Author(s):  
David R. Thornton ◽  
Robert A. Sadowski ◽  
Philip A. Henry
Keyword(s):  
High Pressure ◽  
Heat Exchanger ◽  
Transient Analysis ◽  
Low Pressure ◽  
Lower Pressure ◽  
Pressure Side ◽  
Analysis Methodology ◽  
Large Pressure ◽  
Process Plants ◽  
Shell And Tube

As part of operations, petrochemical and process plants sometimes require the exchange of heat between a high pressure fluid and a lower pressure fluid in shell-and-tube heat exchangers. In most cases, the high pressure fluid exists on the tubeside and the lower pressure is on the shellside. While rare, it is possible for a tube inside the exchanger shell to rupture suddenly, releasing the high pressure fluid into the shellside. If the pressure of the high pressure fluid exceeds the design pressure of the low pressure shell or its attached piping, it might be possible for the resulting pressure in the low pressure side to exceed permitted values. In such cases, API 521 provides guidance on assuring that sufficient pressure relief is available to limit the pressures on the heat exchanger(s)’ low pressure side. An overpressure analysis per API 521 can include both steady-state and transient analysis methods for determining that the pressures remain within acceptable levels. In situations where a large pressure differential exists between the high and low pressure sides of the exchanger, the transient, hydraulic analysis of the tube rupture event can be used as a tool to help mitigate over pressure. After briefly discussing the analysis methodology, this paper discusses some of the practical considerations and decisions that normally go into conducting the analysis.

Reducing Energy Consumption for Seawater Desalination through the Application of Reflux-Recycle Concepts from Oil Refining

2013 ◽  
Vol 295-298 ◽  
pp. 1456-1462 ◽  
Author(s):  
K. E. Ting ◽  
H.T. Ng ◽  
H.C. Li
Keyword(s):  
High Pressure ◽  
Energy Consumption ◽  
Specific Energy Consumption ◽  
Low Pressure ◽  
Hybrid Membrane ◽  
Oil Refining ◽  
Pressure Side ◽  
Seawater Desalination ◽  
Feed Concentration ◽  
Membrane Processes

The application of the concepts in oil and gas distillation to membrane desalination process to lower the energy cost for seawater desalination was studied in this paper. Drawing on the close analogy between multistage RO and conventional distillation separation processes, a hybrid membrane processes employing reflux and recycle concepts was developed. Reflux in membrane processes involves taking a portion of the effluent stream on the high pressure side and sending it to the low pressure side of the membrane, while recycle involves taking a portion of the permeate stream on the low pressure side and sending it to the high pressure side of the membrane. A predictive model was developed to study the effect of reflux and recycle on the specific energy consumption (SEC) and permeate quality when compared to conventional systems. In this study, the water permeability coefficients of membranes and brine recycle ratios were investigated. The results show that the SEC for a hybrid membrane processes comprising of RO and NF membrane was lower than conventional methods with the same recovery and feed concentration, suggesting that it is feasible to apply reflux and recycle concepts of distillation on desalination. Through the careful selection of RO membranes and NF membranes, benefits of reflux and recycle can be enjoyed for seawater desalination.

Practical Experience With a Mobile Methanol Synthesis Device

2014 ◽  
Author(s):  
Eric R. Morgan ◽  
Tom Acker
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Methanol Synthesis ◽  
Low Pressure ◽  
Practical Experience ◽  
Gaseous Hydrogen ◽  
Water Mixture ◽  
Pressure Side ◽  
Northern Arizona ◽  
Northern Arizona University

Northern Arizona University has developed a methanol synthesis unit that directly converts carbon dioxide and hydrogen into methanol and water. The methanol synthesis unit consists of: a high pressure side that includes a compressor, a reactor, and a throttling valve; and a low pressure side that includes a knockout drum, and a mixer where fresh gas enters the system. Methanol and water are produced at high pressure in the reactor and then exit the system under low pressure and temperature in the knockout drum. The remaining, unreacted recycle gas that leaves the knockout drum is mixed with fresh synthesis gas before being sent back through the synthesis loop. The unit operates entirely on electricity and includes a high-pressure electrolyzer to obtain gaseous hydrogen and oxygen directly from purified water. Thus, the sole inputs to the trailer are water, carbon dioxide and electricity, while the sole outputs are methanol, oxygen, and water. A distillation unit separates the methanol and water mixture on site so that the synthesized water can be reused in the electrolyzer. Here, we describe and characterize the operation of the methanol synthesis unit and offer some possible design improvements for future iterations of the device, based on experience.

Pressure Variation in Low Pressure Side of Shell and Tube Heat Exchanger After Tube Rupture

2014 ◽  
Author(s):  
Ganesh S. Katke ◽  
M. Venkatesh ◽  
N. P. Gulhane
Keyword(s):  
High Pressure ◽  
Heat Exchanger ◽  
Low Pressure ◽  
Pressure Variation ◽  
Operating Pressure ◽  
Pressure Side ◽  
Tube Heat Exchanger ◽  
Analytical Algorithm ◽  
Shell And Tube ◽  
Design Pressure

This paper presents an analytical algorithm to determine the pressure variation on the Low Pressure side of a Shell and Tube Heat Exchanger (STHE) after a tube rupture and its validation using CFD simulation. STHEs are often used for exchanging heat between high-pressure (HP) and low-pressure (LP) fluids in the chemical process industry. In case tube rupture occurs in a STHE having a large pressure difference between HP and LP side, there is a risk of release of significant quantity of fluid from the HP side to the LP side. The consequent pressure build-up can lead to the failure of LP side pressure envelope. Generally, design pressure of the LP side is about 10–20% higher than the operating pressure of the LP side fluid, but well below the operating pressure on the HP side. There is no well-established methodology to design the LP side to withstand sudden release of high pressure fluid following a tube rupture. Three dimensional analyses were carried out using Computational Fluid Dynamics to study the pressure variation in LP side (shell side) of a Gas Cooler and to validate the results obtained from the analytical algorithm. It has been observed that the pressure on the LP side exceeds the design pressure instantaneously due to generation of a pressure pulse after tube rupture. This may lead to damage of LP envelope (shell) and internal structure of STHE.

XV. On the thermal effects of fluids in motion - Part II

1854 ◽  
Vol 144 ◽  
pp. 321-364 ◽  
Keyword(s):  
Thermal Effects ◽  
Low Pressure ◽  
Cooling Effect ◽  
Cotton Wool ◽  
Low Pressures

In the last experiment related in our former paper, in which a low pressure of air was employed, a considerable variation of the cooling effect was observed, which it was necessary to account for in order to ascertain its influence on the results. We therefore continued the experiments at low pressures, trying the various arrangements which might be supposed to exercise influence over the phenomena. We had already interposed a plug of cotton wool between the iron and copper pipes, which was found to have the very important effect of equalizing the pressure, besides stopping any solid or liquid particles driven from the pump, and which has therefore been retained in all the subsequent experiments.

Design and Test Plan of the Supercritical CO2 Compressor Test Loop

2008 ◽  
Author(s):  
Takao Ishizuka ◽  
Yasushi Muto ◽  
Masanori Aritomi
Keyword(s):  
High Pressure ◽  
Critical Point ◽  
Thermal Efficiency ◽  
Supercritical Co2 ◽  
Thermal Power ◽  
Low Pressure ◽  
Fiscal Year ◽  
Pressure Side ◽  
Test Loop ◽  
Pressure Compressor

Supercritical carbon dioxide (CO2) gas turbine systems can generate power at a high cycle thermal efficiency, even at modest temperatures of 500–550°C. That high thermal efficiency is attributed to a markedly reduced compressor work in the vicinity of critical point. In addition, the reaction between sodium (Na) and CO2 is milder than that between H2O and Na. Consequently, a more reliable and economically advantageous power generation system can be created by coupling with a Na-cooled fast breeder reactor. In a supercritical CO2 turbine system, a partial cooling cycle is employed to compensate a difference in heat capacity for the high-temperature — low-pressure side and low-temperature — high-pressure side of the recuperators to achieve high cycle thermal efficiency. In our previous work, a conceptual design of the system was produced for conditions of reactor thermal power of 600 MW, turbine inlet condition of 20 MPa/527°C, recuperators 1 and 2 effectiveness of 98%/95%, Intermediate Heat Exchanger (IHX) pressure loss of 8.65%, a turbine adiabatic efficiency of 93%, and a compressor adiabatic efficiency of 88%. Results revealed that high cycle thermal efficiency of 43% can be achieved. In this cycle, three different compressors, i.e., a low-pressure compressor, a high-pressure compressor, and a bypass compressor are included. In the compressor regime, the values of properties such as specific heat and density vary sharply and nonlinearly, dependent upon the pressure and temperature. Therefore, the influences of such property changes on compressor design should be clarified. To obtain experimental data for the compressor performance in the field near the critical point, a supercritical CO2 compressor test project was started at the Tokyo Institute of Technology on June 2007 with funding from MEXT, Japan. In this project, a small centrifugal CO2 compressor will be fabricated and tested. During fiscal year (FY) 2007, test loop components will be fabricated. During FY 2008, the test compressor will be fabricated and installed into the test loop. In FY 2009, tests will be conducted. This paper introduces the concept of a test loop and component designs for the cooler, heater, and control valves. A computer simulation program of static operation was developed based on detailed designs of components and a preliminary design of the compressor. The test operation regime is drawn for the test parameters.

Practical Experience With a Mobile Methanol Synthesis Device

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Eric R. Morgan ◽  
Thomas L. Acker
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Synthesis Gas ◽  
Methanol Synthesis ◽  
Low Pressure ◽  
Practical Experience ◽  
Gaseous Hydrogen ◽  
Distillation Unit ◽  
Water Mixture ◽  
Pressure Side

A methanol synthesis unit (MSU) that directly converts carbon dioxide and hydrogen into methanol and water was developed and tested. The MSU consists of: a high-pressure side that includes a compressor, a reactor, and a throttling valve; and a low-pressure side that includes a knockout drum, and a mixer where fresh gas enters the system. Methanol and water are produced at high pressure in the reactor and then exit the system under low pressure and temperature in the knockout drum. The remaining, unreacted recycle gas that leaves the knockout drum is mixed with fresh synthesis gas before being sent back through the synthesis loop. The unit operates entirely on electricity and includes a high-pressure electrolyzer to obtain gaseous hydrogen and oxygen directly from purified water. Thus, the sole inputs to the trailer are water, carbon dioxide, and electricity, while the sole outputs are methanol, oxygen, and water. A distillation unit separates the methanol and water mixture on site so that the synthesized water can be reused in the electrolyzer. Here, we describe and characterize the operation of the MSU and offer some possible design improvements for future iterations of the device, based on experience.

Effects of Processing Equipment on Howard Mold and Rot Fragment Counts of Tomato Catsup

1987 ◽  
Vol 50 (1) ◽  
pp. 28-37 ◽  
Author(s):  
RUTH BANDLER ◽  
PARIS M. BRICKEY ◽  
STANLEY M. CICHOWICZ ◽  
JOHN S. GECAN ◽  
PHILIP B. MISLIVEC
Keyword(s):  
United States ◽  
High Pressure ◽  
Pilot Plant ◽  
Nationwide Survey ◽  
Low Pressure ◽  
Eastern United States ◽  
The West ◽  
Processing Equipment ◽  
The Difference ◽  
Pilot Plant Study

Two studies were done to determine the effects of processing equipment on Howard mold and rot fragment counts of tomato catsup. In a pilot plant study in 1980, batches of catsup with known cut-out rot levels were produced and processed through various types of comminution equipment. Urschel and Fitzpatrick mills and homogenizers at 500 to 700 and 1500 to 2000 psi increased mold counts more than twofold over the range of data obtained. Contrary to previous reports, Urschel mills increased rot counts significantly. A nationwide survey was conducted in 1983 to determine if similar effects would be found with well-characterized commercial products. Data were obtained on inline and finished products from 164 lots of catsup produced at 16 plants located across the country. Urschel and Fitzpatrick mills tended to increase mold counts over twofold and caused a slight increase in rot counts. High pressure homogenizers (≥2000 psi) tended to decrease mold counts; low pressure homogenizers (<2000 psi) increased them. Homogenization at any pressure reduced rot counts dramatically. Although mold counts were highest for catsup produced in the eastern United States and lowest for catsup produced in the West, milling and low pressure homogenization were also most prevalent in the East and least prevalent in the West. When the effects of these types of comminution were removed, the difference between regions diminished. Compared with the norm, rainfall levels for the growing regions involved in this survey were fairly typical.

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