Palletised Cask Filling System
Proposed Solution
Two flow stragegies will be investigated:
Two stage; Fast Fill - Slow Fill
Three stage; Medium Fill - Fast Fill - Slow Fill
The proposed soultion will use a coriolis flow meter to dictate the end of the higher flowrate stages based on volume. The slow fill stage and fill completion will be dictated by a guided radar level guage. A constant speed centrifugal pump will be utilised in conjuction with throttling butterly valve to provide the variable flow rate.
In order to evaluate the proposed system meets the requirements a test rig has been designed and constructed in Alloa, progress images can be seen here. The test rig is controlled by a PCS7 system designed as part of this project. The software functionality has also been specified as part of the project however the programming has been outsourced to a control integration provider. The diagram below shows the trial process configuration. Items PU01, VA10 and VA11 are manually controlled and will have no interface to the PCS7 system. The following items will be controlled / monitored by the PCS7 system.
FT01 Siemens Sitrans-FCS400 coriolis flowmeter with Sitrans-FCT030 transmitter
VA01 Bray valve with series 6A (Sipart) positioner
LT01 Siemens LG250 guided radar level transmitter
The basic requirement of the PCS7 system is to control the valve position during the following two separate filling strategies with variable control parameters. All data related to each test is also recorded for later review.
Strategy 1 - Fast Fill / Slow Fill 1.
The valve is regulated to achieve a fast flowrate until a fixed volume has been measured by the flowmeter. 2. The valve is then regulated to achieve a slow flowrate until a pre-set level has been measured by the level transmitter.
Strategy 2 - Medium Fill / Fast Fill / Slow Fill 1.
The valve is regulated to achieve a medium flowrate until a fixed volume has been measured by the flowmeter. 2. The valve is regulated to achieve a fast flowrate until another fixed volume has been measured by the flowmeter. 3. The valve is then regulated to achieve a slow flowrate until a pre-set level has been measured by the level transmitter.
The PCS7 programming is now complete and will be connected to the test rig in the coming days, a two day commissioning period has also been allowed before caring out the proving trials. Screen shots of the PCS7 human machine interface can be seen here.
