1. A petroleum middle distillate composition comprising a Major proportion of a petroleum middle distillate and a minor proportion, sufficient to limit the sedimentation rate of the paraffins contained in said middle distillate, of at least one additive consisting of a product with an average molecular weight of about 300 to 10,000 resulting from the reaction of at least one aliphatic dicarboxylic compound selected from maleic and alkylmaleic anhydrides, alkenyl succinic anhydrides containing 10 to 32 carbon atoms in the alkenyl radical, and -the corresponding dicarboxylic acids and lower alkyl diesters, and at least one primary amine with general formula (I)
7
where R1 represents a monovalent saturated aliphatic radical containing 1 to 32 carbon atoms, Z is selected from the groups NR where R represents a hydrogen atom or a monovalent saturated aliphatic radical containing 1 to 32 carbon atoms, n is a whole number from 2 to 4, and mi is whole number from 1 to 4; whereby said primary amine is used in a proportion of 0.3 to 0.8 moles per mole of said dicarboxylic compound and said reaction is carried out at a temperature of 120 C. to 200 C., and continued until all the volatile products consisting of water andor alcohol formed during the reaction have evolved.
2. A composition according to claim 1 wherein the primary amine (I) consists of at least one polyamine with formula
8
which corresponds to general formula (I) where Z represents the NH group, m is 1 to 4, n is 2 to 4, and R1 is a linear monovalent saturated alophatic radical containing 12 to 32 carbon atoms.
3. A composition according to claim 1 wherein the primary amine (I) consists of at least one polyamine with formula
9
which corresponds to general formula (I) where R1Z represents the group NR2R3 where R2 and R3, which may be identical or different, are each an alkyl radical containing 1 to 24 carbon atoms, n is 2 to 4 and m is 1 to 4.
4. A composition according to any one of claims 1 to 3, wherein the dicarboxylic compound is selected from the group consisting of maleic anhydride, methylmaleic anhydride, n-octadecenyl succinic anhydride and dodecenyl succinic anhydride.
5. A composition according to any one of claims 1 to 4, wherein the reaction is carried out in a hydrocarbon solvent with a boiling point between 70 C. and 250 C. and comprises mixing said dicarboxylic compound with said -compound with formula (I) at a temperature of 30 C. to 80 C. and heating the resulting mixture to a temperature of 120 C. to 200 C. for a period of 1 to 8 hours.
6. A composition according to any one of claims 1 to 5, wherein the middle distillate containing paraffins is a middle distillate with a distillation range between range 150 and 450 C., preferably a gas oil cut with a distillation range from an initial boiling point of 160 C. to 190 C. to a cut point of 350 C. to 390 C.
7. A composition according to any one of claims 1 to 6, wherein the proportion of said additive is 20 to 2000 grams per ton of middle distillate.
8. A method for limiting the sedimentation rate of the paraffins contained in a hydrocarbon mixture comprising introducting into said hydrocarbon mixture a minor proportion, sufficient to reduce the sedimentation rate of the paraffins, of at least one additive consisting of a product with an average molecular weight of about 300 to 10,000 resulting from the reaction of at least one aliphatic dicarboxylic compound selected from maleic and alkylmaleic anhydrides, alkenyl succinic anhydrides containing 10 to 32 carbon atoms in the alkenyl radical, and the corresponding dicarboxylic acids and lower alkyl diesters, and at least one primary amine with general formula (I):
10
where R1 represents a monovalent saturated aliphatic radical containing 1 to 32 carbon atoms, Z is selected from the groups NR where R represents a hydrogen atom or a monovalent saturated aliphatic radical containing 1 to 32 carbon atoms, n is a whole number from 2 to 4, and m is a whole number from 1 to 4; whereby said primary amine is used in a proportion of 0.3 to 0.8 mole per mole of said dicarboxylic compound; and said reaction is carried out at a temperature of 120 C. to 200 C., and continued until all the volatile products consisting of water andor alcohol formed during the reaction have evolved.
9. A hydrocarbon middle distillate composition comprising a major proportion of a hydrocarbon middle distillate and a proportion of 20 to 2000 parts per million of the total composition weight, of at least one compound with the general formula (I):
R1Z(CH2)nNHmH
where R1, Z. n and m are as defined in claim 1, as an additive for reducing the sedimentation rate of the paraffins.
10. A hydrocarbon middle distillate composition comprising a major proportion of a hydrocarbon middle distillate and a proportion of 20 to 2000 parts per million of the total composition weight, of at least one compound with the general formula (I)
R1Z(CH2)nNHmH
where R1, Z, n and m are as defined in claim 1, as an anti corrosion additive.
11. A composition according to any one of claims 9 to 10, wherein the compound of the general formula (I) consits of at least a polyanine having one of the following formula
R1NHCH2)4nNHmH
11
where m is from 1 to 4, n is from 2 to 4, R1 is a linear, monovalent, saturated aliphatic radical containing 12 to 32 carbon atoms and R2 and R3, identical or different, are each an alkyl radical containing 1 to 24 carbon atoms.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A pump control system for pressurized water supply systems comprising:
primary supply pumps that supply chilled water or hot water from a return header to a primary supply header via refrigerators, heat pump chillers, or boilers;
secondary supply pumps that are provided with inverters and supply chilled water or hot water from said primary supply header to a secondary supply header;
a flow sensor that measures the flow from said secondary supply header to said return header;
a pressure difference sensor that measures the pressure difference between said secondary supply header and said return header; and
a controller of the secondary supply pumps that determines a supply pressure from the secondary supply pumps using a flow rate measured with said flow sensor, carries out prescribed calculations based on this supply pressure and a discharge pressure measured with said pressure difference sensor, and outputs a control signal corresponding to the calculated result to said inverters.
2. A pump control system in accordance with claim 1, wherein said controller determines the supply pressure from the secondary supply pumps by substituting a flow rate value measured with said flow sensor for the formula containing the flow rate as a variable.
3. A pump control system in accordance with claim 1, wherein said controller outputs the rotational frequency control signal corresponding to the result of calculation to said inverters.
4. A pump control system for pressurized water supply systems comprising:
primary supply pumps that supply chilled water or hot water from a return header to a primary supply header via refrigerators, heat pump chillers, or boilers;
secondary supply pumps that are provided with inverters and supply chilled water or hot water from said primary supply header to a secondary supply header;
a flow sensor that measures the flow from said secondary supply header to said return header;
a pressure difference sensor that measures the pressure difference between said secondary supply header and said return header; and
a controller of the secondary supply pumps that contains an input-output processing portion which determines said inverter rotational frequency by performing calculations, based on said discharge pressure measured with said pressure difference sensor and a supply pressure calculated by selecting the fixed resistance K0 of the entire system, pipeline constants K1 and K2, and a constant n determined using the formula of head of friction loss using a signal obtained by the measurement with said flow sensor and an external input signal or using tables in the data storage portion.
5. A pump control system in accordance with claim 4, wherein the outside air temperature input signal is used as said external input signal.
6. A pump control system in accordance with claim 4, wherein the seasonal change input signal is used as said external input signal.
7. A pump control system in accordance with claim 4, wherein the load change input signal is used as said external input signal.
8. A pump control system in accordance with claim 7, wherein the load availability factor change input signal is used as said load change input signal.
9. A pump control system in accordance with any one of claims 1 to 8, wherein said controller contains an input-output processing portion that determines said inverter rotational frequency so that the discharge pressure from said secondary supply header is a prescribed constant discharge pressure for a prescribed period from the start of operation.
10. A pump control system in accordance with any one of claims 1 to 8, wherein said controller contains an input-output processing portion that determines said inverter rotational frequency so that the discharge pressure from said secondary supply header is increased by a prescribed value for a prescribed period at every prescribed time interval.
11. A pump control system in accordance with any one of claims 4 to 8, wherein a monitor signal input portion that inputs monitor input signals into said input-output processing portion, a monitor display portion and a data memory portion are provided.
12. A pump control system in accordance with any one of claims 1 to 8, comprising an operation display portion that is provided in said controller and displays the operating status.
13. A pump control system in accordance with any one of claims 1 to 8, comprising a primary external communication portion that is provided in said controller and displays the operating status in a remote place via the remote communication means.
14. A pump control system in accordance with any one of claims 1 to 8, comprising a secondary external communication portion that is provided in said controller and changes the settings of parameters necessary for operation from a remote place via the external communication means.