The advantages of ejectors - simplicity, reliability, low weight and low capital cost - can be diminished when condensers are used and a water ring pump is added, particularly in view of the high consumption levels of cooling water or power.

JetEval 3.0 has been developed to take maximise the efficiency of existing ejector systems in respect of both performance and operating costs.
 

• Establishes the operating parameters required to ensure your existing system achieves its full potential.
• Investigates opportunities to reduce operating costs using criteria such as the impact of cost variation of steam, cooling water and power.
• Promotes efficient use of resources.
• Eliminates time spent performing tedious and complicated calculations to identify optimum operating conditions.
• Multi-currency facility allows costs to be calculated in US$, British pounds or any other user defined currency.

JetEval will be of use to process engineers, plant engineers and energy managers with an interest in saving money and achieving plant performance by improving understanding of their vacuum producer.
 

Four versions of JetEval 3.0 are supplied:

1. JetEval with Surface Condensers
2. JetEval with Direct Condensers
3. JetEval with Surface Condensers with Water Ring Pump
4. JetEval with Direct Condensers with Water Ring Pump

A 30 day e-mail and fax support service is provided.
The software comes with comprehensive electronic documentation and examples.
Please note that Microsoft Excel is not supplied with JetEval.

Click here to download an example. File size is 410Kb.

Software Application
Click here to view a list of applications for which JetEval can be used.

Four Stage Systems
In-line arrangements of ejectors and inter-stage condensers with an after-condenser (direct or surface) can be evaluated for suitability and operating costs.

The compression of each stage is limited to the key values between 1.6 and 10. Motive steam expansion is limited to values between 10 and 8000. Condensers are water-cooled and parallel water supply used. Separate programs are available for systems with surface and direct condensers and those using water ring pump for the final stage.

Five Stage Systems
A separate page allows an independent single stage to be examined for compression between 5 and 10 and for motive steam expansion between 8000 and 1,000,000. This can be used to evaluate 5 stage ejector systems where the above limitations practically apply.

Principle of Operation
In this group of programs the operating parameters of the vacuum producer are known. The motive steam usage is therefore a determined parameter. There is however the possibility of testing and optimising some of the other input parameters. Such evaluation, with the aid of iteration, establishes the impact of the other operating parameters on the performance of the vacuum producer. This can lead to significant improvement in its performance.

Source of Data
The performance of the ejectors is based on the graphical correlation of compression with motive steam expansion to produce the entrainment ratio. The raw data is based on practical performance data published in International Chemical Engineering and has been tested against ejector manufacturers and other published data.

N.B. This software is not a design tool for ejectors or condensers but evaluates the different aspects of ejector sizing. Where the system proposed input values these should only be treated as guideline values. Only the conventional single nozzle designs, in-line with conical inlet and exit are considered.
 

• SCN1 Summary sheet - general contents of the spreadsheets
• SCN2 Input gas composition and conditions - on this sheet the composition and the conditions of the suction mixture are selected.
• SCN3 Operating parameters of ejectors and condensers - the ejectors and condenser are selected and modifies to establish a preferred arrangement; up to 4 ejectors in series can be chosen; three inter-stage condensers and one after-condenser can be added.
• SCN4 Summary of arrangement of component parts of vacuum producer, their main thermal parameters, utility requirements and operating costs. This sheet can be used from the very beginning, as it will demonstrate the progress to the complete system. As all the cost are added the cost of the total operation will emerge.
• SCN5 Cost relationships of Ejectors, condensers and cooling water pumps - The costs of these component parts of the system can be selected considering different materials of construction.: the installation factors can also be selected and approximated costs for the system determined.
• SCN6 Operating costs of ejector systems - the costs of the utilities are entered in this sheet; the factors for determination of annualised plant and its maintenance costs can be determined.
• SCN7 Estimate of approximate sizes of ejectors - the sizes for the different components are given: the size of the steam nozzle and the diffuser details can be checked as well as the inlet/outlet nozzle sizes as well as entry and exit pressure losses are evaluated.
• SCN8 High expansion ejector stage - 5^th stage - this independent sheet allows the user to consider the possibility of adding an additional front stage. The addition of this stage would extent the application of a vacuum producing system to 0.01 mbar.
• SCN9 Selection of optimal conditions - in this sheet, using the One and Two Data Inputs Tables or the Solver and the input and calculated data from sheet SC3 are used for optimisation. The calculated relationships can be tabulated and then used for graphic presentation The Excel is very useful in this kind of evaluations.
• SCN10 Testing of an ejector stage - this stand alone sheet can be used to examine an ejector stage for its performance in isolation.
• SCN11 Air leakage in vacuum tightness - three different and simple methods is given to estimate and determine the level of air leakage. The calculated air leakage values can be considered in the main system calculations in sheet SC3.
• SCN12 Saturation in vapour/gas mixtures - the composition of the gas/vapour mixtures generally and at the condensers are evaluated with the aid of this sheet. Condensation conditions for some other selected vapours than water vapour can also be considered. Other vapours where vapour pressure vs. temperature relationships are known can be added.

• ESR1 Summary sheet - general contents of the spreadsheets
• ESR2 Input gas composition and conditions - on this sheet the composition and the conditions of the suction mixture are selected.
• ESR3 Operating parameters of ejectors, Water Ring Pump (WRP) and condensers - the ejectors and condenser are selected and modified to establish a preferred arrangement; up to 3 ejectors in series can be chosen; three inter-stage condensers can be added. The WRP is in the last stage. The WRP can be a single or a double stage.
• ESR4 Summary of arrangement of component parts of vacuum producer, their main thermal parameters, utility requirements and operating costs. This sheet can be used from the very beginning, as it will demonstrate the progress to the complete system. As all the cost are added the cost of the total operation will emerge.
• ESR5 Cost relationships of Ejectors, condensers and cooling water pumps - The costs of these component parts of the system can be selected considering different materials of construction.: the installation factors can also be selected and approximated costs for the system determined.
• ESR6 Operating costs of ejector systems - the costs of the utilities are entered in this sheet; the factors for determination of annualised plant and its maintenance costs can be determined.
• ESR7 Estimate of approximate sizes of ejectors - the sizes for the different components are given: the size of the steam nozzle and the diffuser details can be checked as well as the inlet/outlet nozzle sizes as well as entry and exit pressure losses are evaluated.
• ESR8 High expansion ejector stage - 5^th stage - this independent sheet allows the user to consider the possibility of adding an additional front stage. The addition of this stage would extent the application of a vacuum producing system to 0.005 mbar.
• ESR9 Selection of optimal conditions - in this sheet, using the One and Two Data Inputs Tables or the Solver and the input and calculated data from sheet SC3 are used for optimisation. The calculated relationships can be tabulated and then used for graphic presentation.
• ESR10 Testing of an ejector stage - this stand alone sheet can be used to examine an ejector stage for its performance in isolation.
• ESR11 Air leakage in vacuum tightness - three different and simple methods is given to estimate and determine the level of air leakage. The calculated air leakage values can be considered in the main system calculations in sheet SC3.
• ESR12 Saturation in vapour/gas mixtures - the composition of the gas/vapour mixtures generally and at the condensers are evaluated with the aid of this sheet. Condensation conditions for some other selected vapours than water vapour can also be considered. Other vapours where vapour pressure vs. temperature relationships are known can be added.

• EDN1 Summary sheet - general contents of the spreadsheets
• EDN2 Input gas composition and conditions - on this sheet the composition and the conditions of the suction mixture are selected.
• EDN3 Operating parameters of ejectors and condensers - the ejectors and condenser are selected and modifies to establish a preferred arrangement; up to 4 ejectors in series can be chosen; three inter-stage condensers and one after-condenser can be added.
• EDN4 Summary of arrangement of component parts of vacuum producer, their main thermal parameters, utility requirements and operating costs. This sheet can be used from the very beginning, as it will demonstrate the progress to the complete system. As all the cost are added the cost of the total operation will emerge.
• EDN5 Cost relationships of Ejectors, condensers and CW pumps - The costs of these component parts of the system can be selected considering different materials of construction.: the installation factors can also be selected and approximated costs for the system determined.
• EDN6 Operating costs of ejector systems - the costs of the utilities are entered in this sheet; the factors for determination of annualised plant and its maintenance costs can be determined.
• ECD7 Estimate of approximate sizes of ejectors - the sizes for the different components are given: the size of the steam nozzle and the diffuser details can be checked as well as the inlet/outlet nozzle sizes as well as entry and exit pressure losses are evaluated.
• EDN8 High expansion ejector stage - 5^th stage - this independent sheet allows the user to consider the possibility of adding an additional front stage. The addition of this stage would extent the application of a vacuum producing system to 0.01 mbar.
• EDN9 Selection of optimal conditions - in this sheet, using the One and Two Data Inputs Tables or the Solver and the input and calculated data from sheet SC3 are used for optimisation. The calculated relationships can be tabulated and then used for graphic presentation The Excel is very useful in this kind of evaluations.
• EDN10 Air leakage in vacuum tightness - three different and simple methods is given to estimate and determine the level of air leakage. The calculated air leakage values can be considered in the main system calculations in sheet SC3.
• EDN11 Saturation in vapour/gas mixtures - the composition of the gas/vapour mixtures generally and at the condensers are evaluated with the aid of this sheet. Condensation conditions for some other selected vapours than water vapour can also be considered. Other vapours where vapour pressure vs. temperature relationships are known can be added.

• EWD1 Summary sheet - general contents of the spreadsheets
• EWD2 Input gas composition and conditions - on this sheet the composition and the conditions of the suction mixture are selected.
• EWD3 Operating parameters of ejectors, water ring pumps (WRP) and condensers - the ejectors and condenser are selected and modified to establish a preferred arrangement; up to 3 ejectors in series can be chosen; three inter-stage condensers can be added. The water ring pump is the last in any arrangement.
• EWD4 Summary of arrangement of component parts of vacuum producer, their main thermal parameters, utility requirements and operating costs. This sheet can be used from the very beginning, as it will demonstrate the progress to the complete system. As all the cost are added the cost of the total operation will emerge.
• EWD5 Cost relationships of Ejectors, WRP, condensers and CW pumps - The costs of these component parts of the system can be selected considering different materials of construction: the installation factors can also be selected and approximated costs for the system determined.
• EWD6 Operating costs of ejector systems - the costs of the utilities are entered in this sheet; the factors for determination of annualised plant and its maintenance costs can be determined.
• EWD7 Estimate of approximate sizes of ejectors - the sizes for the different components are given: the size of the steam nozzle and the diffuser details can be checked as well as the inlet/outlet nozzle sizes as well as entry d exit pressure losses are evaluated.
• EWD8 High expansion ejector stage - 5^th stage - this independent sheet allows the user to consider the possibility of adding an additional front stage. The addition of this stage would extent the application of a vacuum producing system to 0.01 mbar.
• EWD9 Selection of optimal conditions - in this sheet, using the One and Two Data Inputs Tables or the Solver and the input and calculated data from sheet SC3 are used for optimisation. The calculated relationships can be tabulated and then used for graphic presentation The Excel is very useful in this kind of evaluations.
• EWD10 Air leakage in vacuum tightness - three different and simple methods is given to estimate and determine the level of air leakage. The calculated air leakage values can be considered in the main system calculations in sheet SC3.
• EWD11 Saturation in vapour/gas mixtures - the composition of the gas/vapour mixtures generally and at the condensers are evaluated with the aid of this sheet. Condensation conditions for some other selected vapours than water vapour can also be considered. Other vapours where vapour pressure vs. temperature relationships are known can be added.